Agenda

Research on System Identification of Vehicle Model for Model Based Reinforcement Learning Automated Parking

F2020-ACM-004

ACM - Automated and Connected Mobility

Dr. Shaoyu Song, Tongji University, CHINA
Prof. Dr.-Ing. Hui Chen, Tongji University, CHINA
Dr. Jiren Zhang, Tongji University, CHINA
Mr. Fengwei Hu, Tongji University, CHINA

Interaction-aware planning and optimal control strategies for automated parking can be derived by model-based reinforcement learning (MBRL). For MBRL based parking, collision avoidance and performance guarantee benefit from the use of vehicle model integrated in the agent for planning parking trajectory. However, the vehicle model significantly influences the training process and final parking accuracy. To improve the parking performance, a model refined RL based automated parking is proposed using system identificated transfer function model. Vehicle kinematic model, dynamic bicycle model, speed and steering transfer function models approximating the longitudinal and lateral dynamic characters of the chassis control are used for comparison in this study.

To obtain the identificated model, first, the kinematic model is adopted in reinforcement learning, which is implemented with Monte Carlo tree search (MCTS) and neural network (NN), a less precise parking planner is obtained and the order sequence. Second, the real vehicle data are collected to obtain response characteristics of chassis control system using the order sequence. Then, the vehicle model is used to train a reinforcement learning model. The receding horizon search scheme for the motion planning and control is realized via tree search guided by trained NN. The NN learns the experience of tree search. MCTS search stronger moves for parking, resulting in the reinforcement of parking planning and control in the next iteration. In order to speed up the off-line learning process, multithreading parallel computing is employed, which encourages each instance of simulation with different strength of action exploration. A sampling strategy of increasing sampling times on-the-fly is proposed to promote the robustness of the proposed algorithm.

The influence of different vehicle models on the learning process and control is studied by the simulations. It shows that low order transfer function models are preferable for the proposed method. The real vehicle experiment validates the effectiveness of the proposed method.

Coupling Apollo with the CommonRoad Motion Planning Framework

F2020-ACM-019

ACM - Automated and Connected Mobility

Ms. Xiao Wang, Technische Universität München, GERMANY
Ms. Anna-Katharina Rettinger, Technische Universität München, GERMANY
Prof. Dr.-Ing. Matthias Althoff, Technische Universität München, GERMANY
Dr. Md Tawhid Bin Waez, Ford Motor Company, UNITED STATES

Positioning Sensor System for Transmodular Mobility

F2020-ACM-042

ACM - Automated and Connected Mobility

Mr. David Bierbuesse, RWTH Aachen University, GERMANY
Mr. Eduard Heidebreicht, RWTH Aachen University, GERMANY
Mr. Tobias Meinert, RWTH Aachen University, GERMANY
Mr. Mauricio Chaves-Vargas, upBUS UG (haftungsbeschränkt), GERMANY
Prof. Dr. Renato Negra, RWTH Aachen University, GERMANY
Prof. Dr. Kai-Uwe Schröder, RWTH Aachen University, GERMANY

Worldwide, regions are on the verge of collapse due to an ongoing urbanization and an increasing number of cars. To relieve overcrowded roads, future urban mobility has to become more flexible and more efficient. The idea of transmodular mobility is to change and share different transportation carriers within a higher-level transportation system. This enables and combines the efficient use of different carrier systems like railways, buses, ropeways or aircraft and increases passenger convenience. Practically, this would mean that different transportation carriers share the same kind of passenger cabins. For instance, a passenger cabin can perform as a bus to reach small and narrow streets and for particular tracks, it would transform into an urban ropeway to benefit from its higher passenger throughput. However, the critical part of this transformation is the coupling process. Therefore, reliable coupling interfaces are required which must be precisely aligned to perform a successful coupling procedure. In this regard, reliable sensor systems are required which can provide precise positioning data of the coupling interfaces for their counterparts.

Conventionally, automotive sensors for range detection purposes either consist of radar or sonar-based systems. Automotive radars are known for a comparable large detection range and can cover up to hundreds of meters. However, the resolution is typically in the range of a few centimeters and even more. Sonar-based systems feature less detection range and are mostly used for short-range detection of obstacles in direct proximity to the sensor. Due to their high resolution and low production costs, they are used for a wide range of park assist systems. Nevertheless, what conventional radar and sonar-based sensor systems have in common is that they do not distinguish between particular obstacles without further signal processing. This means, objects around the sensor can be detected but cannot be identified. However, object identification can be achieved by more advanced systems like LIDAR, camera-based or radar-based imaging techniques. This, in turn, comes with an increasing amount of signal processing and production costs.

This paper presents a new concept of a positioning sensor system for transmodular mobility without the need for complex image and signal processing capability. It is based on a sonar system approach, in which the transmitting nodes and receiving nodes are separated. Thereby, the transmitting node can serve as a reference point on the target object (e.g. passenger cabin) and the receiving node can be placed on the locating object (e.g. transportation carrier), respectively. In this regard, both objects are related to each other in a local reference system. The sensor system is extended by an auxiliary radio link for synchronization purposes. It can cover a range of more than 5 meters with a maximum positioning resolution in the millimeter range.

Human vs. Automation - Who Drives the Future?

F2020-ACM-044

ACM - Automated and Connected Mobility

Dr.-Ing. Václav Jirovský, Czech Technical University in Prague, Faculty of Transportation Sciences/Faculty of Mechanical Engineering, CZECH REPUBLIC

Human species is currently standing on a junction, where it shall decide how it will further develop new technologies. Within the rapid technological evolution during last hundred years, human was designing technology to support him in many challenges - to lift heavier things, to reach further distances, to heal more people. With introduction of IT technologies, numerous visionary high-tech solutions entered homes. High capacity modern communication technologies allow human not only to share large amount of data, but also not to share any information – people share bytes, but according to social scientists they don’t share valuable information as they did in past. While i.e. standard for road vehicle brakes had 8 pages in 1970s, current print has more than 80, but does not contain 10 times more information. Human has silently entered an era, where technology is often created for technology, not for human. In today’s daily life, it is much more difficult to find valid and valuable information in data smog. Similar applies to road transportation – a socio-technological system, whose control is widely decentralized. We are searching for solutions to enhance transport safety and to increase infrastructure throughput in new technologies, while we forget that transport is not the source of the problem, but the consequence of human’s need to move. Thus, the solution is not on a technological level, but on a system organization level.

One of the highly promoted technological solution is autonomous driving. However, if we study the literature we cannot find anything explaining the automation as the only right way and as an achievable solution to road transport problems. No in-depth interdisciplinary study exist about the influence of autonomous road transportation on the society. The numbers showing positive expectations have more economical and marketing background, rather than technological or social. Every new product or prototype is being promoted with standard marketing approach. MIT’s social study on management in technological companies points out incompetent decision making on high levels of management primarily due to complexity of modern technological systems, which cannot be understood neither by one CEO, nor by number of narrow oriented specialists. Still, the evolution of autonomous systems in the past decade is at least interesting. We are already attacking physical limits of sensors. New algorithms have to pursue the chase for low energy demands. Yet, the human brain needs just about 25 Watts at full load, while it is able to perform highly complex and accurate probabilistic estimations. When driving a road vehicle, average driver does a mistake emerging into an accident once in ca. 270 000 km. This leads to an average driver’s reliability of 99,99996% on a driven distance. According to several accident researches, majority of accidents is caused by minority of drivers. The proposed article is aiming to discuss the achievable safety benefits of autonomous driving in comparison with human driver and with changes on system level, thus pointing out the main pillars of comprehensive autonomous road transport study.

Assessing the Readiness of Infrastructure for Automated Vehicles from a Safety Perspective

F2020-ACM-065

ACM - Automated and Connected Mobility

Mrs. Lina Konstantinopoulou, EuroRAP, BELGIUM
Mr. Anthony Germanchev, ARRB, AUSTRALIA
Mr. Marko Ševrović, University of Zagreb, CROATIA
Mr. James Bradford, iRAP, UNITED KINGDOM

Evaluating Autonomous Functions Performance Through Simulation Using Interoperable Sensor, Vehicle, and Environment Models

F2020-ACM-067

ACM - Automated and Connected Mobility

Dipl.-Ing. Serge Laverdure, ESI Group, FRANCE
Dr. Mokrane Hadj-Bachir, ESI Group, FRANCE
Ing. Philippe De Souza, ESI Group, FRANCE
Dr. Dominique Gruyer, Ifsttar, FRANCE

The evaluation, validation, certification, and homologation of connected and automated autonomous vehicles will require more and more virtual testing because of a new level of system complexity the automotive industry has never faced before. Ensuring the robustness, accuracy, and reliability of the perception stages of an “intelligent” and automated vehicle is recognized as one of the challenges for the transition of future mobility means to the higher levels of autonomous driving. From a technological perspective, safety is enforced using combinations of sensors systems exploiting different physics principles used by GPS, by optical sensors, by near or thermal infrared sensors, by electromagnetic sensors and by ultrasonic sensors.

The consistency of the performance verification, expected for the embedded processing relying on artificial intelligence software stacks, depends on the driving environment’s characteristics. It is now obvious that real testing should evolve accordingly and should be completed by virtual testing. Therefore, the industry has embraced the idea of introducing simulation methods to support such validation.

At ESI and with our strategic research and development partner University Gustave Eiffel (merge between previously IFSTTAR and 5 other organisms) we are working on the development of new interoperable and interconnected simulation solutions offering the proper agility related to the integration of new methods.

In the new generations of simulation platform, the problem is to address a complex multi-layer simulation task not only processed by one software and one computer but by several interoperable remote platforms (i.e Dynamics vehicle modelling, sensors modelling, communication modelling, and traffic modelling…). Such a simulation platform must respect important constraints such as the interconnection with real-time data management and processing software, or the capability to share the simulation components, the processing stages, and the driving functions across multiple applications and/or computers.

Simulation can evaluate the performance of complex systems from well-defined scenarios and configurations. It intervenes in several phases of system manufacturing in the design and exploitation phases. With virtual prototyping, simulation can be used to predict in real time the system behavior with respect to its control in order to implement optimal strategies. It is also used for verification, validation and improvement of choices in the design phases.

Our technical paper aims to present what we did with partners and customers in order to confirm the value brought by such new simulation solution.

Keys words: ADAS, Autonomous-vehicles, Sensors, Interoperability, Real-time.

Real-time Trajectory Planning and Vehicle Control for Automated Turning Traveling to the Specified Exit Point

F2020-ACM-069

ACM - Automated and Connected Mobility

Dr. Eng. Takeshi Takiyama, Osaka City University, JAPAN
Dipl.-Ing. Jinichi Fujita, Osaka City University , Graduate school., JAPAN

Methodology for Automated Definition of Critical Scenarios

F2020-ACM-073

ACM - Automated and Connected Mobility

Mr. Thaddäus Menzel, IDIADA Fahrzeugtechnik GmbH, GERMANY
Mr. Thiago de Borba, IDIADA Fahrzeugtechnik GmbH, GERMANY

The field of automated driving has been the focus of research in both, academia and industry in the recent decades. Thanks to the advancements in sensor technology currently used for Advanced Driver Assistance Systems (ADAS), automatization of several parts of the driving task was enabled. However, the introduction of new technologies into the market requires a testing phase. Different test methods can be applied to assess the automated driving functions and their features. Nevertheless, the systematic test of functions for driver assistance systems requires the identification and analysis of a huge number of traffic scenarios. Since most traffic scenarios are not challenging, an approach that automatically generates critical driving scenarios can reduce the testing efforts and costs.

This paper presents a methodology for automated definition of critical scenarios, which is composed of seven steps: define a critical maneuver, define the logical scenario, model the critical maneuver using a mathematical description, define the assessment criteria, obtain the concrete scenarios, specify a performance improvement method, and obtain the boundary scenarios. Firstly, Independent if the validation/homologation is based on a virtual or a field test, the tests should be focused on the most critical situations, since the test phase is costly. The selection of critical scenarios, based on critical maneuvers, is an important phase to develop testing methods. Thus, the critical maneuver selected was the lane change maneuver.

The logical scenario defined describes the event where Ego drives in highway, presenting certain speed and acceleration, and due to a traffic jam, the front vehicle and the rear vehicle, on the adjacent lane, are stationary and there is a considerable distance between Ego and the rear vehicle. After, the mathematical modelling of the lane change maneuver was performed. Composed of three parts, the trajectory planning, which is responsible to generate the desired trajectory that ensure a safe lane change maneuver based on different driver style, the second is the vehicle model, which describes the longitudinal and lateral motion of the Ego vehicle, and the last is the driver model, which is responsible to drive Ego vehicle along to the planned trajectory.

The assessment criteria was based on the safety distances and on the maximum lateral acceleration performed during the maneuver. The concrete scenarios were generated by variating three parameters, in this case, relative velocity between Ego and the front vehicle, the distance between Ego and the front vehicle, and alpha, the coefficient that affects the lane change time. Then, the performance improvement approach was applied, using the k-Nearest Neighbor Classifier, to reduce the computational elapsed time. After completing the first six steps, the concrete scenarios have been classified as critical and non-critical. Lastly, through the analysis of each neighbor point, it was possible to reduce the result space, to a few number of scenarios that can be easily manipulated, the boundary scenarios. Thus, the proposed methodology shown to be an efficient method for the definition of critical scenarios, since thousands of scenarios could be generated and classified in a matter of seconds.

Sensor Time Synchronization in Smart Road Infrastructure

F2020-ACM-083

ACM - Automated and Connected Mobility

Mr. Numan Senel, Technische Hochschule Ingolstadt, GERMANY
Prof. Dr. Gordon Elger, Technische Hochschule Ingolstadt, GERMANY
Prof. Dr. Andreas Festag, Fraunhofer IVI Applied Research Center for Connected Mobility and Infrastructure, GERMANY

In smart cities, infrastructure-side sensors are already used to increase safety, to mitigate traffic congestion and to reduce pollution caused by vehicles. In the future, infrastructural safeguarding is expected to get a large potential due to availability of advanced infrastructure sensors(camera,radar,lidar) and vehicle-to-infrastructure(V2I) communications. In principle, installations of infrastructure-side sensor systems can be divided into two main categories as temporary and permanent. Permanent systems are typically installed for highly used part of urban environments such as city centers, whereas temporary systems are setup for events in cities(concerts,sports games,etc.) with a temporally high density of traffic participants. For both categories different networking options(wired,wireless) as well as sensor data fusion methods (centralized, decentralized data fusion) are possible in order to meet requirements of the specific use case. In this paper, we consider two main architecture options:(1)wired networking with centralized data fusion(centralize architecture) and (2)wireless networking with decentralized data fusion(decentralized architecture).

In the centralized network architecture, the we assume that raw data from multiple sensors will be transmitted to a central processor unit(master). In this architecture, a single node handles the data processing and the fusion process. In the decentralized network architecture, every sensor is equipped with a computing and a communication component. Sensors use a co-located processor unit(slave) to, preprocess data and to transmit these data to a master node. In both architecture options, the master node will be responsible for combining all inputs from multiple sensors to form a common estimate for future state. A centralized architecture requires high-bandwidth connectivity between the sensors and the master, whereas the preprocessing in the decentralized approach has lower demands on the networking bandwidth.

Considering the two architectures the synchronization of the sensor time strongly impacts the state estimation. Sensor nodes need to synchronize their operation and collaborate to accomplish the sensing task. For example, in order to track a vehicle, sensors need to report the location and detection time of vehicle to master node. Then, the master node combines the information to estimate the location and velocity of the vehicle. Evidently, if the sensors do not have a common timescale, the state estimation will be inaccurate. Other aspect is how old the fused data(estimation) are before it delivered to road participants. When road participants receive a current estimation at the timestamp T2, these data represent state at time T1. The time difference between T1 and T2 depends on primarily on the network delay and process time of sensor data. For performance evaluation of the network options with respect to time synchronization the data processing will be separated as an additional source of delay.

In this paper, we study the two architecture options for a smart road infrastructure. The study is based on prototype system using the Robot Operating System(ROS) and cameras, whereas also other sensors(radar,LiDAR) are considered. We specifically assess the impact of sensor time synchronization on the reliability of the sensor data fusion and evaluate the latency between the acquisition of sensor data and reception of the data by the road participants.

Scenario Based Testing of Automated Driving Systems: A Literature Survey

F2020-ACM-096

ACM - Automated and Connected Mobility

Dipl.-Ing. Demin Nalic, University of Technology Graz, AUSTRIA
Dipl.-Ing. Tomislav Mihalj, TU Graz, AUSTRIA
Dipl.-Ing. Maximilian Bäumler, TU Dresden, GERMANY
Dipl.-Ing. Matthias Lehmann, TU Dresden, GERMANY
Prof. Dr.-Ing. Arno Eichberger, TU Graz, AUSTRIA

Research on Electromagnetic Vibration and Noise Characteristics of Double-rotor Permanent Magnet Synchronous In-wheel Motor

F2020-ADM-030

ADM - Advanced Vehicle Driveline and Energy Management

Prof. Dr.-Ing. Lijun Zhang, Tongji University, CHINA
Mr. Jie Xu, Tongji Univeristy, CHINA
Dr.-Ing. Dejian Meng, Tongji Univeristy, CHINA

This paper presents a method based on the finite element simulation, the electromagnetic field, electromagnetic force, electromagnetic vibration and electromagnetic noise characteristics of a double-rotor permanent magnet synchronous in-wheel motor under multiple operating conditions are systematically studied. On the integration of previous methods, a program of multi-physics modeling and analysis of electromagnetic vibration and noise of motor is set up. Firstly, a new electromagnetic structure design of double-rotor permanent magnet synchronous in-wheel motor is proposed. Based on Maxwell stress equation, the analytical model of the radial electromagnetic force of the motor is established. The spatial domain, time domain and frequency domain analysis of the internal and external electromagnetic force and torque ripple of the double-rotor permanent magnet synchronous in-wheel motor are carried out by means of finite element simulation. Analysis shows that the radial electromagnetic force before the 5th order is mainly influential, tangential electromagnetic force before the 4th order is mainly influential.

With the increasing of order, the amplitude is gradually reduced. The amplitude of the first order is the highest. According to the different modeling methods of stator windings, four finite element models in 3D structural field are designed for the double-rotor permanent magnet synchronous in-wheel motor. Then, the effects of quality and stiffness of the effective length and end of stator windings on the stator modal frequency are summarized and compared. The results show that the effect of winding mass and stiffness on the overall modal frequency of the stator is nearly canceled. After that, the 3D structural field model of the double-rotor permanent magnet synchronous in-wheel motor is used to simulate the transient dynamics under radial concentrated force loading. Based on the simulation results, the inner and outer lateral deformation of stator is analyzed in time domain and frequency domain.

Finally, the harmonic response analysis of 3D structural field model of the double-rotor permanent magnet synchronous in-wheel motor is proposed, and the 3D sound field boundary element model of electromagnetic noise is established. The acoustic boundary element analysis under multiple operating conditions is carried out, including sound pressure analysis of stator surface, sound pressure analysis of field point and analysis of sound pressure frequency response characteristics at different field points. The results show that the electromagnetic noise of motor is more sensitive to the high frequency excitation, and the sensitivity of the electromagnetic noise in the radial position is significantly larger than that of the axial position. The analysis process proposed in this paper can provide support for the prediction, optimization and analysis of influencing factors of electromagnetic vibration and noise during the period of motor design.

Raising the Thermal Limits of an Electrical Motor Based on an Air Gap Winding by Applying Improved Laminated Layers and Optimized Cooling Duct Geometries

F2020-ADM-040

ADM - Advanced Vehicle Driveline and Energy Management

Dr. Joerg Sauerhering, Otto-von-Guericke-University-Magdeburg, GERMANY
Dr. Gunar Boye, Otto-von-Guericke-University-Magdeburg, GERMANY
Prof. Dr. Frank Beyrau, Otto-von-Guericke-University-Magdeburg, GERMANY
Mr. Sergey Perekopskiy, Otto-von-Guericke-University-Magdeburg, GERMANY
Mrs. Olena Stamann, Otto-von-Guericke-University-Magdeburg, GERMANY

Due to their electro-mechanical behaviour, electrical motors are able to generate high power densities. For a 20 kg motor based on a modified air gap winding, a mechanical load of 80kW is theoretically possible. However, the achievable power density is generally limited by the thermal loads induced by Joule heating due to the Ohmic resistances in the motor’s wiring.

This paper discusses the potentials of cooling channel modifications, such as the overall geometry as well as surface variations, to enhance the convective heat transfer from the solid material in the coolant with focus on motors using an air gap winding. The convective heat transfer acts as a relevant thermal resistance, which becomes critical at elevated loads, because it is lies between the wiring, acting as a heat source, and the liquid coolant, acting as heat sink. The thermal resistance of the interface material between the wiring and the stator is in the same order of magnitude as the convective heat transfer. These non-metallic materials such as foils, coatings and glues for electrical insulation and mechanical bonding are highly limited in their temperature resistance. To evaluate the behaviour of modified cooling channels and investigate novel interface materials under motor-like conditions, experimental and numerical methods are employed to determine thermo-physical properties, heat and mass transfer and finally the temperature distributions. The experimental results are discussed in comparison with numerical and analytical models and validated thereby.

Because of the limited possibilities for experimental investigations within a real electrical motor, a flat test bed, based on the boundary conditions of an existing 16” wheel hub motor was developed. The Ohmic heating was realised, applying a thin sheet foil of Inconel, so that specific heat loads up to 100 kW/m² could be realised. Here, the surface temperature could be measured contact-free at a high optical resolution, using infrared thermography. The most advantageous test bed feature is the optical accessibility of cooling channels which allows the visualisation of fluid flow regimes.

As results, the influence of large-scale coolant duct geometry modifications on the motor temperatures and hydraulic characteristics as well as of small-scale modifications will be presented in comparison to non-modified geometries. Also, the outcomes and capabilities of novel thermal interface materials consisting of laminated foils will be discussed and an outlook on a modified motor design to increase the thermal limits will be given.

Efficient commercial powertrains – How to achieve a 30% GHG reduction in 2030

F2020-ADM-054

ADM - Advanced Vehicle Driveline and Energy Management

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Mr. Dieter van der Put, FEV Group GmbH, GERMANY

In order to reduce greenhouse gas emissions from the transport sector, the EU has agreed on new regulations to limit CO2 emissions of new heavy-duty vehicles over 16 tons by 15% from 2025 onwards and by 30% from 2030 onwards compared to the 2019 reference. These CO2 targets pose a major challenge, especially for the heavy-duty sector. The increase in freight traffic and vehicle size as well as weight restrictions limit the reduction potential of energy consumption. Moreover, the total costs of ownership (TCO) play a decisive role in which technologies find their way into this competitive market. Recent studies show that new energy sources from renewable energies will not have a noticeable effect on reducing CO2 emissions in the transport sector until 2030.

In this transition, a significant portion will be achieved by vehicle measures, like e.g. aerodynamic and rolling resistance improvements, as well as intelligent mobility vehicle functionalities.

To reduce CO2 emissions of long-haul trucks, the focus during the next decade will continue to be on optimizing the efficiency of the powertrain driven by a combustion engine. The improvement of the combustion efficiency is one part of the possible and necessary measures.

An additional potential is to recycle a part of the waste energy, generated during operation, wherever and whenever it can be used efficiently. Because of region specific legislations, applications and market demands, prior to 2025 a short term flexible integration is key, therefore requiring a modular architecture. It consists of four major systems:
– Energy converters for recovering loss energy from braking operation and exhaust enthalpy like Integrated Starter Generator (ISG) or Waste Heat Recovery systems (WHR)
– Electrically supported aftertreatment solutions to also meet the next level of emission limits
– 48V board network
– Electrified engine components like electrically driven auxiliaries, electrically assisted charging or an electrically driven low-pressure EGR pump to allow the combustion engine to be optimized throughout the entire operating range
The presentation describes the concept of such a modular electrified HD Longhaul Truck. Based on driving cycle simulations, the potential of the various modules, different configurations and applications are estimated.

Furthermore, measures like alternative fuels (e.g. CNG, LNG, H2) will become available to further reduce CO2 emissions. As further initiative in this paper, intelligent mobility vehicle functionalities will be presented, making use of truck and cloud connectivity information and adapted to the customer specific truck operation requirements.

Combined Cycle Gas Turbine System Optimization for Extended Range Electric Vehicles

F2020-ADM-055

ADM - Advanced Vehicle Driveline and Energy Management

Dr. Eng. Charbel Mansour, Lebanese American University, UNITED STATES
Ms. Aya Barakat, Lebanese American University, UNITED STATES

Capacity Characteristics Analysis and Remaining Useful Life Estimation Method of Ternary Lithium Battery Pack

F2020-ADM-060

ADM - Advanced Vehicle Driveline and Energy Management

Mr. Weijian Li, South China University of Technology, CHINA
Prof. Dr. Fengchong Lan, South China University of Technology, CHINA
Prof. Dr. Jiqing Chen, South China University of Technology, CHINA
Dr. Yigang Li, South China University of Technology, CHINA

Objective: Lithium-ion batteries have been widely used in electric cars as the source of power with its advantages of high energy density. The development and use of electric vehicles are affected by the performance degradation of the battery with cycling and ageing. However, the present researches on the battery cycle life are mainly focused on the single cell rather than battery packs, which is different from the actual situation of electric vehicles provided energy by battery packs. This paper examines the degradation characteristics of the battery pack during the charge and discharge cycle and suggest effective model to characterize the capacity degradation and predict the remaining useful life (RUL) of lithium-ion battery pack.

Methods: An experiment was carried out for researching the degradation characteristics of the ternary lithium battery pack which is used in a electric car. The battery pack is tested for 400 charge and discharge cycles, in which the voltage and capacity data of the battery pack are collected through battery management system and test equipment. Random vector functional link (RVFL) network model is trained to track the pack’s degradation trend over its cycle life based on experimental data analysis. Compared with RVFL, several approaches such as statistical models, Kalman filtering and Particle filtering are also applied to predict the remaining useful life of the pack.
Results: From the analysis of experimental data, the remaining useful life of the battery pack drops from 37.271 Ah to 36.094 Ah after 400 cycles. At the end of discharge, the voltage distribution of the batteries in the battery pack is inconsistent, with a maximum difference up to 0.28V. When individual batteries reach the upper limit of charge or lower limit of discharge more quickly, the energy of the battery pack cannot be fully utilized and the remaining useful life is limited. The prediction results show that, Kalman filter and particle filter have errors in battery RUL prediction due to the form of state function. It can be seen in the prediction results at cycle 300 that RVFL model is more accurate to predict the battery pack remaining useful life trend.

Conclusion: Different from the remaining life of a single battery, the inconsistency of battery capacity within a battery pack is an important factor limiting the overall battery pack life. The degree of capacity inconsistency of the batteries in the battery pack will further increase with cycling and ageing of the pack. Data-driven prediction models, such as SVM, neural network models, when performing predictions in 100 cycles, the amount of data available for training is insufficient to accurately predict RUL. Model-driven Kalman filtering and particle filtering prediction methods are limited by the form of model equations. As the number of cycles increases, Kalman filtering and particle filtering prediction methods are less accurate than SVM and RVFL.

Application of PM Gearset in Automotive Gearbox

F2020-ADM-069

ADM - Advanced Vehicle Driveline and Energy Management

Ing. Ondřej Miláček, CTU in Prague, CZECH REPUBLIC
Prof. Gabriela Achtenová, CTU in Prague, CZECH REPUBLIC

A New Engine Concept to Control the Ignition Timing of HCCI Combustion: Piston Assisted Compression Ignition (PACI)

F2020-ADM-073

ADM - Advanced Vehicle Driveline and Energy Management

Dr. Louis Sileghem, Ghent University, BELGIUM

The New Solutions of Energy Utilization of the Exhaust Gases of the Internal Combustion Engines Through Hybrid Turbochargers

F2020-ADM-081

ADM - Advanced Vehicle Driveline and Energy Management

Ing. Rares Lucian Chiriac, "Transilvania" University, ROMANIA
Prof. Dr.-Ing. Anghel Chiru, "Transilvania" University, ROMANIA

Dog Clutch Without Circular Backlash – Design Optimization Using Multi-Body Simulationx

F2020-ADM-083

ADM - Advanced Vehicle Driveline and Energy Management

Ing. Michal Jasný, Czech Technical University in Prague, CZECH REPUBLIC
Dr.-Ing. Michal Hajžman, University of West Bohemia, CZECH REPUBLIC
Dr.-Ing. Radek Bulín, University of West Bohemia, CZECH REPUBLIC

The idea of a dog clutch without circular backlash is based on a unique and patented mechanical blocking mechanism which secures the clutch in desired positions – engaged or neutral. Using this blocking mechanism, we can shape the dogs in the way not common for dog clutches ¬ narrower tip than root. This design minimizes the amount of circular backlash typical for dog clutches and thereby improves ride quality. It also enables disengagement under load which can fasten the gearshift of the dog clutch already being a quick gearshift device. Using external synchronization is necessary. Prototype of the dog clutch with blocking mechanism was successfully tested and proven functional. Improved design regarding to test results will be presented.

Manufacturing of prototypes and their testing is very money- and time-consuming. The same can be said about optimizing the design through comparison of multiple variants. Using multi-body simulation software seems very convenient in this situation. The very basic model of a dog clutch consisting of two dog rings engaging into each other has been already made. Further optimization can be divided into two tasks.
Firstly, the dog clutch with blocking mechanism was initially designed to cooperate with the gear selector system based on manual (MT) or automated manual (AMT) gearboxes. This means that the driver or gearshift actuator acts on the gearshift mechanism until it senses that the gear is fully engaged and cannot move any further. Only then the gearshift force is removed. This ensures that the dog clutch is pushed to its furthest position possible and the blocking mechanism is securely engaged. The first task is to adapt the dog clutch on the gear selector mechanism with kinematic endpoints – typically sequential shifting. In this case the endpoint of the dog clutch depends on the dimensional precision of affected components. In order to provide secure blocking under every circumstance, modification requiring additional flexible part might be necessary. This should make the dog clutch with blocking mechanism suitable for wider variety of applications.

Secondary, quality of the engagement process is affected by large number of parameters. Good gearshift is usually wanted to be quick and silent. This can be controlled using mainly these parameters – mismatch speed, gearshift force, number of dogs, angles of their sides and faces, height of the dogs. Multi-body model created for previous task will be used for design optimizations to fulfill the quality criteria.

Keywords: Dog Clutch; Circular Backlash; Multi-Body Simulation; Engagement Process; Gearshift Quality

Suitability of Using Electric Vehicles in Asia Countries

F2020-ADM-085

ADM - Advanced Vehicle Driveline and Energy Management

Mr. Tiande MO, Hong Kong Productivity Council, CHINA - HONG KONG
Prof. LAU Kin Tak, Swinburne University of Technology, AUSTRALIA
Dr. Chi Kin POON, Hong Kong Productivity Council, CHINA - HONG KONG
Xiaohua Ge, Swinburne University of Technology, AUSTRALIA
Mr. Yu LI, Hong Kong Productivity Council, CHINA - HONG KONG
Mr. Chuliang SHAN, Hong Kong Productivity Council, CHINA - HONG KONG

Data-Based Parameterization of Thermal Models of a Gearbox

F2020-ADM-126

ADM - Advanced Vehicle Driveline and Energy Management

Dipl.-Ing. Erwin Brosch, Forschungsinstitut für Kraftfahrwesen und Fahrzeugmotoren Stuttgart, GERMANY
Mr. M. Sc. Alfons Wagner, Forschungsinstitut für Kraftfahrwesen und Fahrzeugmotoren Stuttgart, GERMANY
Prof. Dr.-Ing. Hans-Christian Reuss, Forschungsinstitut für Kraftfahrwesen und Fahrzeugmotoren Stuttgart, GERMANY

Conventional gear units are installed in almost all vehicles manufactured and developed these days in particular Battery Electric Vehicles (BEV). Despite the already very high sophisticated development of gearboxes, the focus on optimizing mass and efficiency is still important in development. Especially for BEV the efficiency becomes very important. A remarkable feature of a high efficient transmission of a BEV is the low mass and resulting reduced thermal masses. An additional significant challenge is posed by generally higher engine speed of BEVs, which leads to an increase of heat influx in the gearboxes. Overall, the thermal stability of the transmission units decreases, thus the importance of the temperature monitoring is increased. Oftentimes a model is needed for this, especially for topics such as thermal design with regard to temperature distribution or cooling effects on the surface. Under certain conditions having such a model on a test bench facilitates the avoidance of setting a temperature measuring point.

In the scope of this work, a potential solution is shown to infer the inner temperature of the gearbox by using measurable temperature on the outer surface. The surface temperatures of the gearbox can be measured on a test bench by sticking sensors onto it. Furthermore using thermal imaging cameras or other methods based on infrared enable contact free measurements. In order to be able to deduce the inner temperature prevailing in the gearbox from these easily determined surface temperatures, a well-known and frequently used thermal model is created, which is based on the simple foundation of thermal networks. For this concrete application, a thermal network with a small number of thermal nodes and therefore low complexity is created. One node represents the point to be observed inside the gearbox, the others are either a heat sink or heat source or a point where the temperature is known or measured.
Even these relatively simple models reveal a large number of parameters. These need to be determined, because each thermal source or sink as well as each transition needs to be parameterized. Determining these parameters demands detailed knowledge of the particular transmission unit. To avoid this, a method from the field of machine learning is applied. For this purpose, the gearbox to be modelled or an identical gearbox is analyzed on a test bench. Both, external and internal temperatures are recorded. In addition, data such as speed and power, which are usually available anyway, are required. Based on a sufficiently large data set, the optimization criterion for the approach is created.

A method, which is based on evolutionary algorithms is verified using the example of a single-stage differential transmission. For this purpose, measurements on a driveline test bench are collected and evaluated. A model and its parameters are determined and subsequently compared with temperature measurements, derived from the inside of the transmission unit.

Improving Efficiency and Power Density of Hydrogen Engines of Positive Ignition Single-Fuel and Compression Ignition Dual-Fuel designs

F2020-CAF-001

CAF - Conventional and Alternative Fuels and Lubricants

Dr. Alberto Boretti, Prince Mohammad Bin Fahad University, SAUDI ARABIA

The latest advances in power density and efficiency of internal combustion engines (ICEs), both diesel direct injection (DI) compression ignition (CI), and gasoline positive ignition (PI), DI and jet ignition (JI), ICEs, are transferrable to single fuel or dual fuel hydrogen engines (H2-ICEs). H2-ICEs have the potential to deliver peak efficiency about 50%, peak power efficiency above 46%, and cycle average efficiency above 35% when fitted to hybrid powertrains. The major hurdles to achieve these performances are the development of hydrogen injection system. Dual fuel DI diesel-hydrogen CI ICEs have the potentials to deliver extremely low emissions of the regulated pollutants, NOx, unburned hydrocarbons (HC), CO and particulate matter (PM), and CO2 emission. Hydrogen PI ICEs with DI and JI have the potentials to deliver extremely low emissions of the regulated pollutant NOx, practically zero emissions of regulated pollutant PM, and practically zero emission of CO2 (while a small amount of lubricating oil may end up in the combustion chamber, but this amount is negligible).

The PI ICEs allow much higher power densities, being the combustion event controlled by the turbulent mixing rather than vaporization, mixing and diffusion times. Thus, combustion duration is about independent of the engine speed in PI ICEs but increasing with the engine speed in CI ICEs. While combustion of hydrogen only in a CI engine is still troublesome, needing added research and development, much simpler is the use of hydrogen and diesel in a dual fuel CI engine accepting the DI of both diesel and hydrogen. While the dual-fuel DI diesel-hydrogen CI ICEs are a workable short-term replacement of the traditional hydrocarbon fueled PI ICEs, as cryogenic H2-ICES may share infrastructure and fuel system technology with LNG-ICEs, the hydrogen PI ICEs with DI and JI are an even better environmentally-friendly proposal while offering better performances. Simulations are presented for a dual duel diesel-hydrogen engine featuring two injectors per cylinder, one for the diesel and one for the hydrogen.

The coupling of a pilot/pre-injection of diesel with a main injector of hydrogen is straightforward. Mixed modes of combustion are possible injecting part of the hydrogen before, and a part after the diesel injection ignition. The engine has a super turbocharging, where the turbocharger shaft is connected to the crankshaft by gears and a continuously variable transmission. Steady-state maps are presented in detail. Even if this aspect is not investigated, thanks to the super turbocharging, the engine has excellent transient behaviors, in decelerations (energy recovery) as well as accelerations (no turbo-lag). Dual fuel CI ICEs have also the advantage of a hydrogen city driving delivering extremely low emissions of pollutants as well as CO2, and a diesel interstate and rural areas driving delivering still relatively low emissions of pollutants as well as CO2.

Fluid Dynamics Analysis of Bubble Generation Process in Engine Oil Based on Model Experiments

F2020-CAF-007

CAF - Conventional and Alternative Fuels and Lubricants

Dr. Masao Ishihama, Kanagawa University, JAPAN

Bubbles generated in oil pans adversely affect engine lubrication performance. For example, if air bubbles enter the lubrication system to much, they will cause bearing damage and heat exchange performance deterioration. However, the generating process of these bubbles has not been analyzed enough to be used in engine design. Therefore, as a typical case of bubble generation, observation was made with a high-speed camera in a model experiment in which a sprocket on a horizontal axis was rotated near an oil pool surface. These phenomena observed in the experiment were analyzed using fluid dynamics theory.

From the high-speed photographs, three phenomena were identified as the bubble generation processes: 1) releasing air trapped in the pockets between the sprocket teeth, 2) separation of bubbles from the bottom of an oil surface valley caused by oil flow around the rotating sprocket, and 3) entrapment of air by oil droplets dropping on the oil surface.

The first process mentioned above was found to be explained by a model in which liquid accumulated in a channel flows downstream when a weir is suddenly released.

The second process was modeled by the combination of velocity potentials caused by gravity and circulation around the rotating sprocket. The numerical simulation based on this model met well with experiment results.

Concerning the third process, the development of oil film ridge on the rotating sprocket, which becomes large oil droplets entrapping air in bulk oil reserved in a pan, was investigated. To predict the influences of design factors, fundamental equations of motion governing the phenomenon were derived. Order estimation of terms in the equations caused by centrifugal force, viscosity and surface tension was conducted. Then, the equations were solved numerically. As a result, effects of such factors as oil viscosity, surface tension, and gravitational potential on the growth of oil ridge were identified.

Concerning also the third process, formulation and numerical calculation of air trapping in a cavity caused by oil droplet were conducted using surface tension mechanics. This formulation enabled us to calculate the process in which the gravitational and capillary pressures in the oil pool reduced the cavity inlet diameter of the cavity dug down by the oil drop. This theory can explain the experimental result that two oil droplets falling successively tend to generate bubbles. As a result, we improved the method of predicting bubble generation using dimensionless numbers such as Froude and Weber numbers.

These studies will guide our future lubrication system design.

Customer-Focussed Automatic Test Course Design

F2020-DGT-007

DGT - Digital Transformation

Mr. Florian Grober, Volkswagen AG, GERMANY
Dr.-Ing. Andreas Janßen, Volkswagen AG, GERMANY
Prof. Dr.-Ing. Ferit Küçükay, TU Braunschweig, GERMANY

Customer centricity gains increasing importance in vehicle development. With respect to durability testing and approval of prototypes, it causes the requirement for testing procedures which highly comply with the occurring loads during customer operation. In this manner, lightweight construction is enabled and considerable economic advantages are raised by avoiding oversizing as well as undersizing of components. As current state of the art, vehicle manufacturers use special test courses on proving grounds or public roads which must be endured damage-free by the vehicle prototype until a compulsory mileage is reached. Alternatively, the course’s loads can be reproduced on a test rig to reduce the required test time. The definition of these test courses is based on long-standing experiences. According to new trends in the automotive sector, as for example electrification and shared mobility, it can be predicted that the customer loads will change in accelerating cycles. Correspondingly, these previous experiences cannot be used offhandedly for such new questions and existing test courses become invalid. To solve the described problem of inflexibility, this article presents a technology for automatic generation of appropriate test courses from customer field data. The developed algorithm transforms customer-oriented load spectra into a test course that reproduces the occurred loads as good as possible. For this purpose, digital map data is combined with measured track load data and consecutive road segments are assembled to a complete test course by heuristic methods. This resulting course requires a minimum driving distance and induces approximately the same loads as the destination load spectra derived from customer field data. The optimisation can be processed simultaneously for several different load channels. Via using automation and heuristics, a good performance arises and enables a fast as well as flexible generation of tailored test courses pursuant to current demands. In contrast to the inflexible test course concept used so far, the described technique represents a good improvement of customer-oriented testing methodology. Therefore, it provides a great novelty value. In the article, the process of an automatic test course design is demonstrated and validated by means of a real example, which shows the practical applicability. The latter is also proved by the fact that the described method has already been used successfully in the research and development of Volkswagen AG.

upBUS – Electrical, autonomous driving, transmodular bus for public transport systems

F2020-DGT-012

DGT - Digital Transformation

Mr. Tobias Meinert, Institute of Structural Mechanics and Lightweight Design of RWTH Aachen University, GERMANY
Mr. Mauricio Chaves-Vargas, upBUS UG (haftungsbeschränkt), GERMANY
Mr. David Bierbüsse, Chair of High Frequency Electronics, GERMANY
Mr. Eduard Heidebrecht, Chair of High Frequency Electronics of RWTH Aachen University, GERMANY
Prof. Dr.-Ing. Renato Negra, Chair of High Frequency Electronics of RWTH Aachen University, GERMANY
Prof. Dr.-Ing. Kai-Uwe Schröder, Institute of Structural Mechanics and Lightweight Design of RWTH Aachen University, GERMANY

Worldwide, regions are on the verge of collapse due to the ongoing urbanization and an increasing number of cars. In order to relieve overcrowded streets, the airspace above the ground must be opened for urban mobility. Aircraft taxis are the logical option to develop urban airspace for private transport. However from a long-term perspective, these won’t be the solution to the aforementioned traffic congestion problems. In addition to the high energy consumption, aircraft taxis would rather shift individual traffic from the ground level to the airspace. Therefore, only a further development of public transport will be able to solve current and future problems.
upBUS offers the solution by combining the development of two different transport systems, urban ropeways and autonomous electric busses.

Ropeway systems are an ideal solution to use the airspace above the street level. They are known for their low investment and operating costs, their short construction times without traffic obstruction, minimal space and energy requirements, as well as enormous routing flexibility. On the other hand, ropeways are characterized by the problem of network integration, as the stations cannot be positioned in any necessary place. There are also areas, such as historic towns, which cannot be crossed by ropeways. The upBUS approach is to merge urban ropeways and autonomous mini buses into a modular system. On the ground level the vehicles act as autonomous electric buses. In a ropeway station they transform into a ropeway cabin. This transformation process works fully automatically during operation and passengers do not have to switch between different transportation systems. The upBUS vehicle consists of three parts. The electric drive technology and all sensors for autonomous driving are integrated into a skateboard which acts as the driving unit. The ropeway provides a suspension with a connector plate. The third part, the passenger cabin, can either connect to the driving unit or to the connector plate of the ropeway suspension. Thereby, upBUS benefits from the flexibility of buses in combination with the high passenger throughput of urban ropeways. With the upBUS concept, urban ropeways are not a stand-alone solution any longer and can be easily integrated into the public transportation system.

The key technology of this transformation concept can be separated into three parts. First, a specific kind of coupling radar is developed, which provides precise positioning data in order to align the bus with the ropeway suspension. If the parts are aligned within the range of a few centimeters a lifting mechanism in the driving unit hoists the cabin into the suspension. Guiding elements align the two parts within a few millimeters. At this point coupling-interfaces on the roof of the cabin couple with counterparts on the suspension while coupling-interfaces between driving unit and cabin decouple. The cabin leaves the station as a ropeway. The transformation process works vice versa. This paper explains in detail the advantages of this new mobility system and describes the technical parts of the transformation process by designing a first prototype which demonstrates the key-technology in November 2020.

New Approaches to Digitalizing the Design and Validation Process of Complex Mount Bearings with the Focus on Durability

F2020-DGT-016

DGT - Digital Transformation

Dipl.-Ing. Steven Ernst, Chair of Automobile Engineering - Technische Universität Dresden, GERMANY
Dipl.-Ing. Felix Schmid, Chair of Automobile Engineering - Technische Universität Dresden, GERMANY
Dr.-Ing. Kay Büttner, Chair of Automobile Engineering - Technische Universität Dresden, GERMANY
Prof. Dr.-Ing. Günther Prokop, Chair of Automobile Engineering - Technische Universität Dresden, GERMANY

With the continuous digitalization of the vehicle development process, virtual design methods play an increasingly important role. Representative load profiles, which can be determined for example with the aid of multi-body system simulation, are required for the reliable design and validation of complex elastomeric bearings such as engine mounts for conventional and electrified drive trains. Due to the complex material properties and complex designs of today's elastomer and hydro mounts, the virtual representation of these components is a challenging task.

In already published researches (46th Conference of the “DVM Arbeitsgruppe Betriebsfestigkeit”) it could be shown that the current standard characterization of elastomeric bearings using static and dynamic stiffness as well as loss angle is only partly appropriate to build up and parameterize exact models for the virtual load data determination. On the basis of multi-axial load tests of selected engine mounts, which are done at the highly dynamic component test rig of the Chair of Automotive Engineering of the TU Dresden, physical effects with relevance for the durability could be determined. These are multi-axial static, dynamic and transient changes in stiffness and damping properties. With the knowledge of these effects, a complex model was developed which is designed for the representation of high dynamic loads, hydraulic damping and superposition effects of multi-axial excitations. The model is to be used primarily to calculate operating load signals using multi-body system simulation.

Within the context of the research described here, a complex multistep parameter identification procedure based on particle swarm optimization is presented. With this method it is possible to use complex stochastic signals to identify the model parameters. The first step is to determine the static stiffness of the bearing model in the considered main direction. The uniaxial dynamic parameters are identified afterwards. In the following, the dependence of the uniaxial dynamic parameters on the deformation amplitude is evaluated. Finally, the parameters of the model elements are identified which are dependent on the deformation of the secondary directions (multi-axial model components). The described procedure allows a modularization of the complex bearing model, whereby the model complexity can be adapted according to the application.

Multi-axial test rig measurements showed a significant improvement in the image quality of measured load signals compared to standard models for the newly developed model and the parameter identification process. The simulation error is used as evaluation criterion and the signal damage is considered by means of a standard fatigue strength evaluation. Different types of elastomeric and hydromounts are investigated for validation. Furthermore, the simulation quality of the modelling process outside the fitting range is evaluated. With the help of these investigations it can be deduced that the methods work robustly and will be suitable for practical use after a few adjustments. The investigations contribute to an improved and validated digital representation of elastomeric bearings with a focus on load data determination.

A Method for User-Friendly PID-Parameter Optimization for Highly Dynamic Component Test Benches

F2020-DGT-031

DGT - Digital Transformation

Mr. Kai Wolter, Karlsruher Institut für Technologie - Institut für Produktentwicklung, GERMANY

Proportional-integral-differential controllers (PID controllers) are one of the most widespread controller architectures and are used in a large number of technical systems [1]. When operating highly dynamic test benches to investigate the system behaviour of powertrain components with rotating movements, the controllers are often used as speed controllers. In order to reproduce the complex phenomena in such a powertrain as accurately as possible, the high dynamics of the test bench is required. This means that the test bench must be able to vary the speed highly dynamically and at the same time have the least possible unwanted influences on the system under investigation. This enables the system to be disconnected from the overall system to be specifically examined on the test bench with a virtual representation of the remaining system. A large part of this required system dynamics depends on the parameters of the PID controller. The adjustment of the parameters is often based on empirical knowledge and empirical methods, which have existed for several decades and consider a highly simplified system dynamics [2]. These procedures are easy to use, but are characterized by a high experimental effort and limited optimization potential. In addition, there are more and more approaches to perform the controller adjustment using metaheuristic algorithms [3, 4]. These work with detailed system models and are able to map the system behaviour in detail. Consequently, they offer a high optimization potential. Since these approaches are based on detailed knowledge about the adjustment procedure and the system to be optimized, they are not yet practicable for test bench operation with varying systems.

Therefore, the authors present in this paper a method that allows to combine the easy handling of the empirical procedures with the optimization potential of metaheuristics. Thus, the user does not need to have a profound knowledge of control engineering and is guided through the adjustment process in the form of targeted support. For this purpose, the construction of system models by using a library based approach and the possibility of automatic system identification as well as a new optimization function are presented. For these only characteristic values such as overshoot, settling time or rise time have to be selected and a qualitative decision has to be made. This enables a simple and robust adjustment of the controllers.

Literature
[1] Tiwari, P.: Optimization of PID Parameter In Control System Tuning With Multi-Objective Genetic Algorithm 4 (2014) 5, S. 7
[2] Ziegler, J. G. u. Nichols, N. B.: Optimum Settings for Automatic Controllers. Journal of Dynamic Systems, Measurement, and Control 115 (1993) 2B, S. 220
[3] Zhang, J., Zhuang, J., Du, H. u. Wang, S.’a.: Self-organizing genetic algorithm based tuning of PID controllers. Information Sciences 179 (2009) 7, S. 1007–1018
[4] Fan u. Joo (Hrsg.): Design for auto-tuning PID controller based on genetic algorithms. 2009

Optimization Design of Large-displacement Motorcycle Emission Testing Procedures

F2020-EPV-014

EPV - Emissions and Pollutants Caused by Vehicles

Mr. Wanli Yuan, CCIC West Testing Company Limited, CHINA
Mr. Tiande Mo, Hong Kong Productivity Council, CHINA - HONG KONG
Mr. Yu Li, Hong Kong Productivity Council, CHINA - HONG KONG
Mr. Baomin Duan, CCIC West Testing Company Limited, CHINA
Mr. Wei Zhong, China Quality Certification Centre, CHINA

Economic and/or practical points to be addressed
The large-displacement motorcycles, which engine displacements above 600cc, usually have good acceleration, strong power and large heat dissipation. Due to strict emission requirements leads by the new China IV emission standards that give rise to various problems during tests cycles, and the existing testing facilities and conditions cannot fully meet the testing requirements for such motorcycles. Therefore, the test cycle for the emission of pollutants from large-displacement motorcycles needs to be optimized to further ensure the detection accuracy and better provide accurate data support for large-displacement motorcycles.

Methodology
China is currently implementing the China IV emission standards (GB 14622-2016, GB 18176-2016) for motorcycles. Compared with European Union IV emission standards, the most important feature is the durability assessment for actual pollution control devices. This paper makes a detailed comparative analysis for the limitation and detection method of the Type I test, Type II test, Type III test, Type IV test, Type V test and On-Board Diagnostics (OBD) system test for the large-displacement motorcycles, and designed an optimized emission testing technology for large-displacement motorcycle emission test procedures.

Main scientific and technical
Through the analysis for a large number of test results of large-displacement motorcycles, it is considered that they are similar to other types of motorcycles in single emission test procedures for type II test, type III test, type IV test, and OBD system test. However, special features are found in Type I test and Type-V test because of differences in displacement, acceleration and heat dissipation in large-displacement motorcycles. In consequence, it is necessary to optimize the testing technology to provide improvement in emission detection method to ensure the data accuracy. It is believed that the following factors will have an impact on the emission results and shall be strictly controlled and improved:
1. Impact from the fuel;
2. Impact from the driving behavior;
3. Impact from the testing equipment and the ambient environment during the test;
4. Impact from the vehicle maintenance during the test.

Through a large number of motorcycle tests, it has been fully verified that the above four factors have significant impacts on the emission results. The research and verification carried out on the emission test of large-displacement motorcycles can determine how to optimize these four factors to ensure the data accuracy for the emission test of large-displacement motorcycles.

Achieved results
Several factors that impact the large-displacement motorcycles emission test have been fully verified, indicating that the test procedures need to be precisely optimized that suggesting for testing procedures are summarized and given in the following four factors, thereby reducing emission detection errors and ensuring the test accuracy.
1. Standardized training method for the driver
2. Environmental condition control method
3. Environmental background gas concentration control method
4. Fuel control method and requirements

Analytical Investigation of Tire Induced Particle Emissions

F2020-EPV-027

EPV - Emissions and Pollutants Caused by Vehicles

Mr. Toni Feißel, TU Ilmenau, GERMANY
Prof. Dr.-Ing. Klaus Augsburg, TU Ilmenau, GERMANY

Research and/or Engineering Question/Objective:
The fine dust contribution (<10µm) of motor vehicles represents a considerable health risk for people in urban areas. Due to an increasing percentage of electric vehicles, exhaust emissions are steadily reduced. Consequently, particles from non-exhaust sources (brake, tire and road ware) are considered to be the future main vehicle related pollutant. While regenerative braking, tungsten carbide coatings and filter devices can effectively reduce brake wear emissions, there is currently no methodology available in order to reduce tire wear particles, road abrasion and resuspension. In addition, the tire is one of the main sources of environmental microplastic pollution. Although there are initial approaches to determine the emission characteristics of tire and road ware particles, there is a lack of basic understanding of the underlying physical processes.

Methodology:
The particle flow around the vehicle wheelhouse is dominated by highly dynamic vortex structures. The numerical flow simulation (CFD) is a well suited tool for the investigation of these processes and allows a detailed analysis of the particle-flow interaction. Within this paper, a CFD flow model of a vehicle wheelhouse is presented, which analytically describes the underlying physical effects of particle dispersion by the vehicle tire. The CFD model was applied in order to define a suitable measurement strategy for the measurement of TRW particles based on a measurement vehicle.

Results:
In order to develop a CFD Modell for tire-induced particle emissions, comprehensive analysis of mesh generation, geometric influencing factors and turbulence models was conducted. An essential element of the presented model is the modelling of the wheel rotation, tire-road contact and tire-profile related effects. In addition, particle models were adapted according to the physical properties of tire and road wear particles. In a second step, the CFD methodology was applied in order to design a constant volume sampling system (CVS) which ensures a maximum sampling and transport efficiency for TRW particles.

Limitations of this study:
In general, numerical simulation requires strong simplification of the physical problem and can cover aspects of the flow and particle behavior only partially. Thus, more experiments are necessary to fully validate the CFD model.

What does the paper offer that is new in the field in comparison to other works of the author:
The paper offers a new CFD-based tire and road wear model including flow processes in proximity to the tire-road interface, in order to describe tire induced particle emissions.

Conclusion:
Within this paper a novel CFD-based methodology is presented whereby special emphasis was placed towards the modelling of tire-induced particle emissions. This model was applied in order to design a constant volume sampling system that ensures a maximum sampling as well as transport efficiency for TRW particle measurement.

KEYWORDS – Tire and Road Wear Particles (TRW), Particle Resuspension, Non-Exhaust-Emissions, Computational Fluid Dynamics (CFD), Constant Volume Sampling System (CVS)

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High Fuel Pressure and Multiple Injection of Gasoline for the Particle Emission Reduction Under Cold Conditions

F2020-EPV-028

EPV - Emissions and Pollutants Caused by Vehicles

Mr. Naoki Yoneya, Hitachi, Ltd., JAPAN
Mr. Sebastian Blochum, Technical University of Munich, Institute of Internal Combustion Engines, GERMANY
Prof. Dr.-Ing. Georg Wachtmeister, Technical University of Munich, Institute of Internal Combustion Engines, GERMANY
Mr. Yoshihito Yasukawa, Hitachi Automotive Systems Europe GmbH, GERMANY
Mr. Yuki Sugiyama, Hitachi Automotive Systems, Ltd., JAPAN

The global warming and the drain on fossil fuel resources are serious concerns which lead to a desire to improve the fuel efficiency of vehicles and reduce exhaust emission. Considering the market penetration of battery electric vehicles (BEV) and the Well to Wheel CO2 emission, hybrid electric vehicles (HEV) are expected to be the majority for the next decades. As a result, the development of an internal combustion engine is still highly required. The gasoline direct injection (GDI) engine is a promising solutions for complying with future CO2 regulations.

However one of the biggest challenges in GDI engines is to reduce PN (Particulate number) emission. EU commission started the PN emission limit from 2017 with Real Driving Emission (RDE) in the frame of Euro 6d-Temp, which required the Gasoline Particle Filter (GPF) application for most of the gasoline vehicles. The regulation will become further stringent after 2020 by extending the acceptable temperature range down to -7℃. Therefore, the PN reduction technology under extreme cold condition needs to be developed. In this paper, within a collaboration between Hitachi and Technische Universität München (TUM), high fuel pressure up to 50MPa and the multiple injection up to 5 times are investigated as promising countermeasures.

First, the spray measurement was carried out, to clarify the effect of the high fuel pressure and multiple injections on the spray. The penetration reduction could be confirmed only at low load conditions, which was not the case at middle to high loads. With the increase of the injection amount, the benefit of the shorter injection duration by higher pressure seems to be cancelled by the high injection velocity. Therefore the multiple injection is necessary to actively control the penetration and reduce the spray wall impingement.

Next, the thermodynamic engine test for PN emission measurement and the endoscope measurement for PN source identifications are carried out. For realizing the cold environment condition, an engine cooling facility was installed to the single cylinder research engine, which can cool down the engine head down to -7℃. The PN reduction effect of the high fuel pressure up to 50MPa was investigated by the optical measurement. PN could be reduced at low load due to the better homogeneity and less wall wetting, but the tendency was not consistent at mid-high load. The reason was estimated to be the longer penetration, cancelling the benefit of better evaporation and causing wall wetting.

The DoE-based optimization of the multiple injection strategy was carried out, as the initial screening of the promising multiple injection concept. The response surface model was built up, and promising injection concepts were obtained. The optimized injection strategy with triple injection showed the best PN reduction effect.
Based on the DoE results above, the promising injection strategies were further investigated with higher fuel pressure and larger number of injections. Finally 5 times injection with 50MPa showed the significant PN reduction at the high load area.

Real-Time Torque Estimation of an Air Conditioner Compressor for the CO2 Emissions Reduction from an Engine Vehicle

F2020-EPV-071

EPV - Emissions and Pollutants Caused by Vehicles

Mr. Jung-Myung Kwak, Hanon systems, REPUBLIC OF KOREA
Mr. Yong-Hee Kim, Hanon systems, REPUBLIC OF KOREA
Mr. Peter Zawadzky, TE, GERMANY
Mr. Simon Scherner, TE, GERMANY

The Control Strategy Research on Reduction of High-Frequency Noise and Vibration for Permanent Magnet Synchronous Motor

F2020-MCF-002

MCF - Mobility Comfort

Ms. Lulu Wei, Jilin University, CHINA
Prof. Fangwu Ma, Jilin University, CHINA
Dr. Hongbin Yin, Shandong University of Technology, CHINA
Dr. Liang Wu, Jilin University, CHINA
Mr. Hui Gao, China Automotive Technology and Research Center Co., Ltd., CHINA

Vibration Transmissibility Analyses of Asymmetric Cantilevered Structures with Screw Fastening by Mode Equivalent Factors

F2020-MCF-006

MCF - Mobility Comfort

Dr. Gyoko Oh, Tokyo Roki Co., Ltd., JAPAN

The majority of fatigue failures in automotive components are due to vibrations, and it is important to analyze vibration response properties. Using the measured data of a symmetric sample and four kinds of asymmetric screw fastening cantilevered structures consisting of a steel block, copper weights, steel pipes, and joints modeling the components, vibration parameters of the first translational resonance, the second translational resonance, and the rotating direction resonance peaks were identified through analytical models of viscous damping. The influence degrees of the second and the rotating direction resonances were taken into account using mode equivalent factors of the amplitudes, and a simplified analytical method with high accuracy was proposed and verified.

The samples which were supplied for measurements had a main mass m and a main length l, as well as added masses mad and added lengths lad. The measured vibration response data were summarized, and the transmissibility curves were plotted in figures according to the resonance frequency in a lateral excitation. To treat the sample as one mass point and as the Voigt model, a physical model was built and the equation of motion was set up. Equations of vibration transmissibilities of the system were obtained by solving the equations of motion. The equations were directly used for the translational mode 1. For the translational mode 2, the maximum vibration amplitudes were not always at the tip of the sample, and a mode equivalent factor η2 was used. The equation for the composed transmissibility was written as T=T1+η2 T2, where η2 = 0 at f ≦ f1. For the rotating mode θ and φ, and the third translational mode 3, mode equivalent factors ηϑ, ηφ, and η3 could also be used, and the equation for the total transmissibility was written as T＝T1+ηϑ Tϑ+η2 T2+ηφ Tφ+η3 T3 ＝T1+∑ηn Tn, where ηn = 0 at f ≦ fn-1, and subscript n indicates the mode. The vibration parameters were identified using the measured peak data, and the theoretically calculated transmissibility curves using the parameters were compared with the measured curves. The calculated curves accorded closely with the measured curves over frequency. The frequency ratios f2/f1 of the second translational response peak to the first one were 5.6-11.2, and their transmissibility ratios T2/T1 were 0.02-0.18.

The lowest transmissibilities of the valley between the two resonance peaks were 0.3-0.49, and excessive damping did not occur. In the samples with rotating vibration around the vertical axis, the f1 and the f2 declined when the added mass increased, but the spring coefficient did not greatly change. In the samples with rotating vibration around the node in the vertical direction, the f2 declined greatly when the added mass increased, and the spring coefficient also declined greatly. By changing the parameters of the model, vibration characteristics of similar systems can be estimated and predicted theoretically with the mode equivalent factors, indicating general versatility of this method.

Start-Up Transient Vibration Analysis and Control of a Vehicle Equipped with a 3-Cylinered Engine

F2020-MCF-012

MCF - Mobility Comfort

Dr. Yan Jin, China Automotive Engineering Research Institute Co. Ltd, CHINA

Factors Affecting Squeak Characteristics of Plastic Parts And Its Prevention Solutions

F2020-MCF-020

MCF - Mobility Comfort

Mr. Amit Kumar, Mahindra & Mahindra Ltd, INDIA
Mrs. Edlin Lewis, Mahindra & Mahindra Ltd., INDIA
Mr. Mohammed Riyazuddin, Mahindra & Mahindra Ltd., INDIA
Mr. Raghavendran Prasath, Mahindra & Mahindra Ltd., INDIA
Mr. Sandeep Shukla, Mahindra & Mahindra Ltd., INDIA

Study and Reduce the Interior Noise Roughness During Acceleration

F2020-MCF-057

MCF - Mobility Comfort

Dr. Yan Jin, China Automotive Engineering Research Institute Co. Ltd, CHINA

Vibro-Acoustic Reciprocity Analysis Using Dodecahedral Sound Source and its Application for Material Assessment

F2020-MCF-062

MCF - Mobility Comfort

Mr. Nitesh Anerao, Mahindra & Mahindra Ltd., INDIA
Mr. Tulesh Kumar, Mahindra & Mahindra Ltd., INDIA

NVH (Noise, Vibration and Harshness) is an important aspect of vehicle design since it is one of the biggest influencing factors for customer while making decision to buy a vehicle. Hence, automotive engineers strive to design superior cabin compartment to maintain pleasant levels of noise, vibration and the overall experience within the vehicle. Transfer function analysis is primarily used to quantify the relative relationship between source and receiver region.

The focus of this paper is to measure vibro-acoustic transfer function using reciprocity approach instead of direct impact test measurement to evaluate the frequency response of heavy layer barrier materials. Normally, it is difficult to mount and quantify the correct response of such heavy damped materials in usual random incidence sound transmission test since its performance is very sensitive to leakage (less than 1% required). The purpose of demonstrating the vibro-acoustic reciprocity in a vehicle is to show that the principle works good even for non-linear system like vehicle, in most cases where mutual coupling effects are negligible and hence at most area the frequency response for tested material holds true even at vehicle level. The reciprocal measurement involves usage of dodecahedral sound source to acoustically excite the cabin from desired seating location and accelerometers being placed at all the response locations of interest on vehicle body. In case of direct measurement, vehicle body is excited using impact hammer and acoustic pressure is measured at desired seating location. It is observed that transfer function calculated with direct and reciprocal measurements showed a good match with overall deviation of less than 2 dB on an average. The reciprocal measurement based transfer function can be used as a logical input for prediction of receiver level sound pressure data/sound quality or prediction of source strength depending on the subject of requirement for dynamic tests. The validation helps in optimizing the traditional approach for measuring structural response using vibro-acoustic transfer function in frequency range of 80 - 5000 Hz. The traditional method involving impact hammer test for predicting response at various points in vehicles is a time taking process and inaccessible measurement locations are prone to error. The linearity of the reciprocity measurement is checked for various locations in vehicles and found to be working satisfactorily in frequency range of 80 - 5000 Hz where frequencies till 1000 Hz are very well correlated and deviations are observed above 1000 Hz comparatively for all measurement locations.

The main idea of this paper is the application of above reciprocity principle for assessment of acoustic materials used for noise control. The reciprocal approach of predicting transfer function is used to capture frequency response of heavy layer barrier material which uniquely characterizes its behavior. To verify that material comparison holds true, comparison of two test samples with known performance are also made and it is seen to correctly quantify the frequency behaviour of one sample with respect to other.

Vibration Behavior of Powertrain Test Benches - Measurement, Analysis and Modelling

F2020-MCF-066

MCF - Mobility Comfort

Mr. Alfons Wagner, FKFS - Research Institute of Automotive Engineering and Vehicle Engines Stuttgart, GERMANY
Dipl.-Ing. Erwin Brosch, FKFS - Research Institute of Automotive Engineering and Vehicle Engines Stuttgart, GERMANY

Electric powertrains have unique characteristics, which imply new requirements and need additional testing methods within the powertrain test benches. This work presents a unique vibration model of a complete powertrain test bench based on both measurements and theoretical analysis of a real hardware system. The modelling method is a contribution towards understanding and analyzing the new vibration behavior of the electric powertrain on powertrain test benches, which refers to a shift towards higher frequencies.

The procedure, which is developed in this work is based on a model of the physical vibration path of a driving machine within a test bench. The model is created and validated based on measurement data that are obtained from several tests then the overall model of the vibration of the complete test bench is constructed. Based on the entire mechanical system of the test bench, a simplified physical model of an individual machine within the test bench is first created in Matlab Simulink. Then, the individual models are combined together to form an overall system model including coupling parameters. The simplified model is constructed as an oscillatory multi- body mass spring damper system composed of several individual components. Special attention is taken when modelling the linking conditions in order to obtain realistic results from the overall model. The parameters existing in the model are determined either empirically from test data or theoretically with the help of the test bench documentation.

In order to verify the individual model, several tests are carried out. For this purpose, high-resolution vibration measurement technology is applied to an existing test bench machine. In addition to that, vibration sensors are installed on the machine base and bed. Different speeds are approached and measurement data are recorded under steady state conditions in addition to dynamic tests. These tests are carried out under no load conditions. The test bench machine is also operated with and without explicit imbalance excitation and the relevant measurements are recorded synchronously at high frequency of 1 kHz. During verification procedure of the individual components, the model is compared with the measurement data and the deviations are iteratively eliminated by adapting the parameters used in the previous iteration. This procedure is repeated until the model matches the measurement data of the real test bench machine and the error is within a specified tolerance band. Finally, the measurements are repeated for the entire test bench and the overall model is validated.

Based on a simplified physical model of a test bench machine the vibration behavior of the entire test bench is modelled using measurement data of no-load tests at several speed with and without explicit imbalance excitation. Studying the vibration behavior of powertrain test benches allows the testing of electric and electrified powertrains safely on existing test benches.

Kalman Filter Based Active Noise Control for Vibro-Acoustic Cavities

F2020-MCF-088

MCF - Mobility Comfort

Dr. Amrita Puri, Indian Institute of Technology, Jodhpur, INDIA
Prof. Subodh V. Modak, IIT Delhi, INDIA
Prof. Kshitij Gupta, IIT Delhi, INDIA

This paper explores use of the Kalman filter to estimate modal states in Modal Filtered-X LMS algorithm. Modal Filtered-x LMS (M FxLMS) algorithm is an adaptive algorithm, recently proposed by the authors, to minimize global acoustic potential energy of a vibro-acoustic cavity for reducing global level of noise in the cavity. For a weakly coupled vibro-acoustic cavity, global acoustic potential energy can be expressed as sum of squares of modal amplitudes of rigid walled acoustic modes of the cavity. Therefore, the algorithm was formulated to minimize sum of squares of modal amplitudes of the rigid walled acoustic modes.

The M FxLMS algorithm turned out to be modal counterpart of the conventional FxLMS algorithm. In the conventional FxLMS algorithm, sum of squares of pressures at the location of microphones is minimized and hence, values of acoustic pressure at the location of error microphones and physical secondary path impulse responses are used. A physical secondary path impulse response represents the variation of acoustic pressure at location of error microphone when secondary source is driven by an impulse function. In the M FxLMS algorithm, sum of squares of modal amplitudes of some chosen acoustic modes is minimized and hence, values of modal amplitudes of the chosen acoustic modes and modal secondary path impulse responses are used.

A modal secondary path impulse response represents the variation of modal amplitude of a particular acoustic mode when secondary source is driven by an impulse function. In the earlier study, modal amplitude of the acoustic modes are obtained using information of acoustic pressure at some discrete locations inside the cavity and information of the chosen acoustic mode shapes at those locations. In that approach, number of the acoustic pressure sensors must be adequately more than number of the acoustic modes contributing in desired frequency range. In a view of reducing number of the acoustic pressure sensors, this paper explores use of Kalman filter to estimate modal amplitudes of the acoustic modes. A modal model of the vibro-acoustic cavity is used in the formulation of Kalman filter for estimation of modal amplitudes of acoustic modes.

A numerical study is carried out on the same irregular vibro-acoustic cavity which was used for the earlier study. An acoustic disturbance acting inside the cavity and a structural disturbance acting on the flexible surface of the cavity are considered. An acoustic control source is used as a secondary source. The study is carried out for three frequencies: a cavity controlled resonance, a panel controlled resonance and an off-resonance frequency. It is found that with the use of Kalman filter; only 6 microphones are required as against the 18 microphones required in the previous approach for the accurate estimation and then, control of modal amplitudes of first 12 acoustic modes.

Concept Level Performance Improvement in Frame with Light-Weighting

F2020-MML-026

MML - Manufacturing, Materials and Lightweight Solutions

Mr. Mihir Bhalerao, Mahindra & Mahindra Ltd., INDIA
Mr. Samir Rawte, Mahindra & Mahindra Ltd., INDIA
Mr. Jeyevijeyan RS, Mahindra & Mahindra Ltd., INDIA
Mr. Hareesh Krishnan, Mahindra & Mahindra Ltd, INDIA

Amongst passenger vehicles, SUVs are mainly constructed Body-on-Frame as it has better off-road capabilities. Frame design must take into consider the vehicle architecture, geometric and functional interfaces, crashworthiness and local and global stiffnesses. The stiffness of the frame directly affects critical vehicle dynamics & NVH characteristics. The vehicle frame contributes to roughly 10% of total vehicle weight. Hence, Light-weighting of the frame will result in significant weight reduction of the overall vehicle. Weight of the vehicle is a critical parameter in fuel economy, material cost and dynamics.

The frame design is a critical platform architecture development as it has direct linkage to architectural dimensions and the platform modularity definitions. Currently, the frame is designed in 3D CAD and taken through a CAE loop. The frame design is iterated until it meets the pre-defined performance targets. This results in extended duration for the architecture freeze and subsequently the entire product development process.
To speed upthe frame design process, a method is proposed to optimize the frame design with respect to the global stiffnesses and weight at the concept stage, even before the first level CAD is prepared. The paper focuses on parameterizing the ladder frame of a vehicle, running structural simulations with a parametric beam model, correlating with the actual values and finally generating a frame concept model from optimization to be taken further for detailed engineering.

The ladder frame is parameterized based on the geometry and sections of the side-members and locations and sections of the cross-members and 46 parameters were generated. The simulations were run in a commercial software where the frame was modelled as beam elements and the joints are modeled as rigid joints. Loads & constraints are applied as per the stiffness test protocols and global stiffnesses are simulated. The results from the simulation were correlated with test results as well as 3D CAE values for internal benchmarks with 90% accuracy. A Design of experiments was run which resulted in a mathematical model which was used to perform optimization.

The optimization generated a concept frame with 20% weight reduction and a 50% increase in Bending and Torsional Stiffness. The results matched with 3D CAE simulation results and the frame taken forward for detailed engineering.
Extremely low simulation time make it possible to run multiple iterations and perform optimization very quickly. The sensitivity and direction of goodness of each parameter which is an output from the simulation helps in further detailing the design. As this new process enables front-loading of CAE during the concept stage which accelerates the process of product development.

Keywords: Frame Design, Global Stiffness, Light-weighting, Parametric Model, Concept Development

The Lightweight Design of Anticollision Beam of 7075 Aluminum Alloy patch panel mixed with Corbon Fiber Reinforced Composites

F2020-MML-031

MML - Manufacturing, Materials and Lightweight Solutions

Dr. Eng. Zhimin Liu, BAIC Motor Co.Ltd., CHINA
Mr. Leigang Chen, BAIC Motor Co.Ltd., CHINA

With the wide application of aluminum alloy in the automotive field, and the reduction of the cost of carbon fiber, the application of aluminum alloy and carbon fiber hybrid materials has become an important direction of the future development of automotive materials. The development of friction stir welding technology makes the connection between different materials easy to realize. In addition, with the development of hot forming technology of ultra-high strength steel and the reduction of hot forming process cost, hot forming products of high-strength aluminum alloy represented by 7075 aluminum alloy began to be applied in automobile industry.

As for the rear anticollision beam, with the increase of energy absorption requirement for low-speed collision, extruded aluminum alloy has been widely applied in the middle and high-end automobiles due to its low process cost. However, due to the limitation of extrusion process, the flexibility of extruded aluminum design is poor, which is not conducive to further lightweight. Therefore, the hot forming technology of 7075 high strength aluminum alloy is considered to further optimize the rear anti-collision beam.Based on friction stir welding prepared for mixed materials, designed four kinds of structure anti-collision beams, which were respectively made of 340LA steel, 6082 extruded aluminum alloy, 7075 hot-forming aluminum alloy and 7075 hot-forming aluminum alloy which patched with carbon fiber reinforced composite (CFRP) plate were designed for one car. In addition, the energy absorption box is designed with several kinds of materials, which were medium-strength steel, extruded aluminum, stamped aluminum and carbon fiber composite respctively. Based on the crash simulation analysis using LS-DYNA, deformation nephogram and curves of maximum invasion of four kinds anti-collision beams were obtained

The results of the intrusion of collider based on crash simulation in the rear low speed impact, indicated that four kinds of bumpers both met the collision requirements by optimizing the shape and size of the anti-collision beam and energy absorption box. Because of the creative using the technology of aluminum hot-forming, as well as friction stir welding of carbon fiber composite patch panel between aluminum plate, the weight of the anti-collision beam assembly was reduced from 4.82kg to 1.10kg, and the weight of this new anti-collision beam assembly mixed with 7075 aluminum and CFRP was 1.38 kg lighter than the 2.52 kg of 6082 extruded aluminum beam assembly. In addition, the results of energy absorption curves shown that the energy absorption box of the new anti-collision beam with has a higher energy absorption effect.

Design And Analysis of Light Weight Helical Gear Limited Slip Differential For Racing Car Applications

F2020-MML-047

MML - Manufacturing, Materials and Lightweight Solutions

Mr. Shrinivas Tarte, BAJAJ Auto India, INDIA

The purpose of this paper is to study and designing of light weight limited Slip Differential. The LSD is transmission device that improves traction capabilities leading to high performance road cars, racing cars. Concentrating on the ability of Helical gear limited slip differential to adapt to different cornering conditions, we designed light weight differential for achieving better performance in racing cars. For the designing purpose mathematical equations were used. All the parts of differential are design under static condition and modeled. Design was then iterated to give various models and analysis was carried out on each design for the improvement. Testing of this differential is then carried out on a Formula SAE car in order to verify the performance of differential. This paper considers use of differential in Formula SAE or similar auto racing competition. Casing of differential that is designed consist of 2 parts left hand casing and right hand casing, Left hand casing gives support to 3 planetary gears which is in mesh with left sun gear. Right hand casing gives support to all planetary gears and right sun gear along with star idler. The planetary gears of left and right casing are in mesh. On extension of both casing there is provision for taper roller bearing mount. Differential is provided with mounting of sprocket.

Differential is a device that differentiates or splits the engine torque and allow both drive wheels to rotate at different speed hence the name differential. Commonly used differential (open differential) allows each of driving wheels to rotate at different speed when each wheels travels different distance through the turn. But it splits the torque equally between both the drive wheels. When one of the drive wheel looses traction due to slippery condition or cornering neither of the wheel gets torque for the propulsion of vehicle. the maximum torque that can be supplied by the engine to the wheels is limited by the traction capabilities of the tire. Since the torque is distributed equally between both wheels, the maximum total torque transferred to the ground is twice the maximum torque available at the tire with the least traction. This is a major disadvantage for low traction situation such as on off-road terrain, or in cases of large weight transfer like that occurring during racing.

During tight cornering weight is transferred from the vehicles inside wheels to the outside ones. The open differential will lead to slipping of the inside wheel thus decreasing the rate of acceleration out of a corner
To overcome this problem Limited slip differential is used. As it differentiates torque and speed, it improves cornering stability and better traction control with direct impact on handling characteristic of car.
In the racing application due to cornering condition, leading to weight transfer on wheels hence there are different traction load on different wheel. Also inertia and weight plays an important role in overall performance of a car. Hence LSD is used which fulfill the needs of different tractional load requirement by differentiating torque

Carbon Fiber Composite Chassis Components, Opportunities and Challenges

F2020-MML-059

MML - Manufacturing, Materials and Lightweight Solutions

Dr. David Wagner, Ford Motor Company, UNITED STATES
Mr. Daniel Mainz, Ford Motor Company, GERMANY
Mr. Thomas Gerhards, Ford Motor Company, GERMANY
Dr. Xiaoming Chen, Ford Motor Company, UNITED STATES

Crashworthiness of C-SMC: a Structural Battery Case for Automotive Application

F2020-PIF-017

PIF - Passive and Integral Safety

Mr. Federico Coren, Tu Graz, Institut of Automotive Engineering, AUSTRIA
Mr. Philipp S. Stelzer, Institut für Polymer Product Engineering, Johannes Kepler University Linz - JKU, AUSTRIA

Collision Prediction for Irreversible Pre-Crash Safety Measures

F2020-PIF-033

PIF - Passive and Integral Safety

Mr. Robert Lugner, CARISSMA Institute of Safety in Future Mobility, TH Ingolstadt, GERMANY
Mr. Maximilian Inderst, CARISSMA Institute of Safety in Future Mobility, TH Ingolstadt, GERMANY
Mr. Gerald Sequeira, CARISSMA Institute of Safety in Future Mobility, TH Ingolstadt, GERMANY
Mr. Kilian Schneider, CARISSMA Institute of Safety in Future Mobility, TH Ingolstadt, GERMANY
Prof. Dr.-Ing. Thomas Brandmeier, CARISSMA Institute of Safety in Future Mobility, TH Ingolstadt, GERMANY

The precise and reliable prediction of vehicle movements based on information from environmental sensors such as radar, camera or LiDAR is an essential constituent of future pre-crash safety functions triggering irreversible actuators. These predictions require novel motion models that go beyond the state-of-the-art and the comparatively low requirements regarding accuracy in today's AEB systems. Because of this, methods for existing driver assistance systems are not suitable for the prediction of crash parameters in inevitable crash situations and the subsequent activation of irreversible systems with ASIL D classification like prospective smart airbags.

The proposed highly accurate inevitability model allows the integration of a specially adapted motion model for worst-case assessment within the physical limits. The focus is on integration into pre-crash functionality with near-field environment models in order to provide reliable information of the expected crash constellation to subsequent crash severity estimation. An adapted single-track model describes the nonholonomic vehicle behavior. Physically possible trajectories for crash avoidance are calculated using Kamm circle as the limitation for the vehicle accelerations. This model is modified to minimize the dependency on the unavailable and hence only roughly estimated vehicle parameters of the collision partner. Innovative concepts for crash severity estimation require detailed information on the expected collision parameters (location, angle, velocities) as well as the estimated times to the inevitable collision.

Depending on the application and the traffic scenario, this information can then be categorized into collision classes. These classes can be defined according to standard crash test scenarios (ODB40, AZT, etc.).
Particularly interesting examples for the inevitability model are critical traffic situations with crossing vehicles. This paper focuses on the effects of different scenario constellations in the urban to rural speed range, on the inevitability model, and the subsequent crash severity prediction. Therefore, heat maps are presented as a suitable tool for the evaluation of the scenarios. They provide a simple illustration of how critical the unavoidable collision is as well as the functional requirements of pre-crash systems in different situations.

The proposed model is the groundwork for further developments and investigations towards a holistic methodology for pre-crash safety systems. The prototype application in a CARISSMA research vehicle is currently in preparation. In addition, the presented methodology will also be extended to investigations of sensor requirements and system tolerances. This enables the comprehensive analysis of sensor systems and algorithms, which are essential components of future irreversible safety systems.

Parameterization of Standard Test Scenarios of Automated Vehicles Using Accident Simulation Data

F2020-PIF-038

PIF - Passive and Integral Safety

Dipl.-Ing. Martin Urban, Fraunhofer Institute for Transport and Infrastructure IVI, GERMANY
Dipl.-Ing. Jorge Lorente Mallada, Toyota Motor Europe, BELGIUM
Dipl.-Ing. Maria Pohle, Fraunhofer Institute for Transport and Infrastructure IVI, GERMANY
Dr.-Ing. Christian T. Erbsmehl, Fraunhofer Institute for Transport and Infrastructure IVI, GERMANY
Dr.-Ing. Pablo Puente Guillen, Toyota Motor Europe, BELGIUM
Dipl.-Ing. Satoshi Taniguchi, Toyota Motor Corporation, JAPAN
Dr.-Ing. Tom Landgraf, Fraunhofer Institute for Transport and Infrastructure IVI, GERMANY

Research objective
In February 2019, the Japanese society of automotive Engineers published a white paper titled »Proposal for the Autonomous Driving Vehicle Test Scenarios Standards«. This white paper presents in a comprehensive way the current development state of a validation method for safety performance, with the aim of safely introducing automated driving systems to the market. As part of the validation method, the white paper proposes thirty highway scenarios that should be used to validate automated driving. The scenarios are defined by combining the road geometry (main road; marge; branch; ramp), the ego vehicle behaviour (lane keep; lane change) and the surrounding environment or behaviour of other vehicles (Cut In; Cut out; Acceleration; Deceleration; synchronic behaviour). The objective of this research is to define the important parameters regarding the behaviour of the ego vehicle in relation to the opponent vehicle, in addition to several geometric and physical parameters needed for the analysis.

Methodology
Based on police recorded accident data, the Fraunhofer IVI has developed a methodology for creating simulation files in order to recreate and obtain the pre-crash phase of these accidents. More than 8,000 cases are available in the current simulation database with around 2,000 of this are highway cases. The simulation results contain detailed trajectories for each participant involved in the accident with speed, acceleration and trajectory information. Each of the 2,000 highway accidents is assigned to one of the thirty scenario groups using a three-step database analysis.
After the assignment process, parameters such as longitudinal and lateral distance, velocity and acceleration or deceleration are calculated for each accident. Subsequently, a statistical analysis is executed for each group that delivers the mean values and standard deviation for each parameter.

Results
The methodology used to obtain the important parameters for each scenario can be recreated and applied to any other database containing similar information to the database used for this study.
The result of the analysis presented in this abstract is a statistical description of the highway scenarios proposed by the white paper. It allows configuring test scenarios for automated vehicles and systems with real world parameters from accident simulations based on accident data recorded by the police in Saxony. Around 2,000 reconstructed accidents are the basic data for the statistical description of thirty highway scenarios.

Limitation
The police recorded accidents on highways in Saxony are the basic data of this study. Therefore, using data from different topographic regions, other traffic regulations or other driver education requirements, may modify the parameters and the results of the analysis.

Key Words
automated driving, test definition, accident scenario, simulation

A Methodology for Building Simulation Files from Police Recorded Accident Data (for ADAS Effectiveness Assessment)

F2020-PIF-039

PIF - Passive and Integral Safety

Mr. Martin Urban, Fraunhofer Institute for Transportation and Infrastructure Systems, GERMANY
Dr.-Ing. Christian T. Erbsmehl, Fraunhofer Institute for Transport and Infrastructure IVI, GERMANY
Dipl.-Ing. Jorge Lorente Mallada, Toyota Motor Europe, BELGIUM
Dr.-Ing. Pablo Puente Guillen, Toyota Motor Europe, BELGIUM
Dipl.-Ing. Satoshi Taniguchi, Toyota Motor Corporation, JAPAN

Research objective
European Institutions have reached an agreement for a new General Safety Regulation (GSR) that mandates the implementation of certain ADAS systems into new vehicles from 2022. This includes advanced emergency braking (AEB) and emergency lane keeping system (ELK), among other systems. In order to assess the performance of such systems, it is required to analyse the pre-crash phase of accidents, which can be done by means of simulating crashes. One widespread database of simulation input data is the GIDAS-PCM, which contains around 10,000 accident reconstructions from two German investigation areas (Dresden, Hannover) since the year 1999. This paper focuses on developing a novel method for generating the pre-crash phase based on police recorded accidents. This allows generating simulations of a large number of accidents. The simulation results can later be used in combination with ADAS models to understand the effectiveness of those systems.

Methodology
The Fraunhofer IVI has access to all police reported accidents within Saxony (region in Germany) since the year 2010. The dataset for one accident contains up to 100 variables including injury severity, accident location and type of accident, among others. The available data contains up to 1 million accidents including fatal accidents, accidents with severe or slightly injured participants as well as accidents with material damage only. Using the information recorded by the police, the description of the accident and the aerial picture of the accident site as a basis, it is possible to create the trajectory for each participant. In order to obtain information on the speed profile of the participants involved in the accident, an analysis of in-depth accident data is carried out that defines the mean values and standard deviation of the speed profiles. The trajectory and speed profiles are used to reconstruct the accident scene and the pre-crash phase with the help of an accident reconstruction software. This information is later extracted and can be used to carry out an effectiveness assessment of ADAS systems which could have been beneficial to the participants.

Results
The newly developed method for creating simulation files by drawing on data from police recorded accidents delivers one main simulation case for each accident and up to 900 variations by using the mean values and standard deviations of initial speed, collision speed and additional parameters. Currently, the Fraunhofer IVI has ~10,000 simulation cases from 2018 and 2019, from which 1.2 million variations can be generated.

Limitation
This methodology has been developed based on the input data available at the Fraunhofer IVI, for the region of Saxony. An expansion of this methodology to other regions or countries would be subject to further studies on the availability of the required input data.

Key Words
accident analysis, simulation, effectiveness assessment, ADAS

Development of an Advanced Vehicle Restraint Systems with Special Consideration of Small Occupants with help of an Adaptive Steering Column

F2020-PIF-042

PIF - Passive and Integral Safety

Mr. Felix Bentgens, Trier University of Applied Sciences, GERMANY
Prof. Dr.-Ing. Peter Koenig, Trier University of Applied Sciences, GERMANY
Mr. Marco Mueller, Trier University of Applied Sciences, GERMANY
Dr. Jaikumar Mayakrishnan, Hindustan Institute of Technology & Science, INDIA
Mr. Raghavendran Pala Raviramachandran, Hindustan Institute of Technology & Science, INDIA

Research and/ or Engineering Questions/ Objective

In the event of an accident, in today’s vehicle belt, airbag systems and steering columns absorb the kinetic energy of occupants in front crashes. Most steering columns are equipped with a deformation device, which provides limited forward displacement of the steering wheel when being impacted dynamically by the occupant. As these features perform on fixed force levels, they deform less when loaded with lower energy, so e.g. when impacted by a smaller occupant. So especially for small occupants the maximum available forward displacement is not used, so they will be decelerated on a higher g-levels than needed.
Student researchers of Trier University of Applied Sciences, Germany, and Hindustan Institute of Technology and Sciences, India, started a joint research program with support of the German DAAD and investigated solution to provide maximum forward displacement for occupants of all sizes. This solution could improve vehicle safety significantly in Western markets with in average larger people (correlating approx. with 50%ile dummy) as well as Asian markets with an in average smaller population (correlating approx. with 5%ile dummy).

Methodology

In current legislation, safety systems such as the steering column must be validated in tests using 50%ile Hybrid III dummies only. A component simulation model with a standard restraint system was set up using HyperMesh and LS-Dyna to investigate kinematics and injury pattern for all available dummy sizes (5-50-95%ile). For the steering column a damping device was developed allowing adaptive force levels with help of magnetorheological fluids.

Results

Various load levels could be developed for the different dummy sizes. The kinetic energy thus could be dissipated over a longer distance so occupant injuries have been reduced. Feasibility studies on the advanced damper have proven the potential of the approach.

Limitations of this study

To date, there is no technical implementation to determine the exact mass of an occupant in a vehicle, therefore only the seat position can be used as indicator for the mass and size. Nevertheless, a progressive absorption characteristic is included which will not load the occupants more than in today’s systems.

What does the paper offer that is new in the field including in comparison to other work by the authors?

Magnetorheological fluids suffer of the problem of sedimentation, so their usage in rarely used restraint systems is critical. The design presented will ensure high level of dilution throughout the vehicle life, what is unique in the market. The solution thus can improve safety for a wide range of occupants in passenger cars and helps minimize or even prevent injuries.

Conclusions

The method provides a general approach for an efficient way of improving occupant safety over a wide range of occupant sizes.

Tagging Real-World Scenarios for the Assessment of Autonomous Vehicles

F2020-PIF-048

PIF - Passive and Integral Safety

Mr. Erwin de Gelder, TNO, NETHERLANDS
Dr. Olaf Op den Camp, TNO, NETHERLANDS

Automatic Car Reverse Braking System Based on a ToF Camera Sensor

F2020-PIF-049

PIF - Passive and Integral Safety

Mr. Rodrigo Negri de Azeredo, Federal University of Parana - UFPR, BRAZIL
Prof. Dr. Ondrej Vaculin, Technische Hochschule Ingolstadt - THI, GERMANY
Prof. Dr. Gustavo Henrique da Costa Oliveira, Federal University of Parana - UFPR, BRAZIL

The proposed paper presents a feasibility study on Time-of-Flight (ToF) cameras for Reverse Autonomous Emergency Braking systems (reverse AEB) and the application of computer vision techniques for automatic target identification in the real-time.

The consumer testing organisations play an important role in the expansion of vehicle safety systems. The New Car Assessment Programme (NCAP) organisations assess vehicle safety considering different areas, for instance in Europe the rating of EuroNCAP consists of four categories: Adult Occupants, Child Occupants, Vulnerable Road Users (VRU) and Safety Assists. One of the tested systems is Autonomous Emergency Braking (AEB), which activates automatically the vehicle's brakes in order to prevent or reduce the severity of a collision. The new EuroNCAP protocol, effective from January 2020, brought the application of AEB also to reverse motion of vehicles to prevent accidents with pedestrians. The Reverse AEB automatically activates brakes when a potential obstacle behind the vehicle is detected. The system has the ability to reduce a significant number of accidents, particularly during parking manoeuvres.

The proposed work aims to investigate the suitability of the innovative PMD technology with a ToF Camera for the reverse AEB. Following the protocol guidelines for the assessment test conditions, the Vehicle Under Test (VUT) should be tested with speeds of -4 and -8 km/h with impact offsets of 25, 50 and 75%. The protocol considers an adult pedestrian target.

However, the presented research goes beyond the requirements of the protocol and addresses the case of a certified child target, which is more dangerous because of its smaller size. The work consists of a data acquisition phase with a real ToF camera sensor in a scenario according to the guidelines of the AEB VRU Systems protocol from EuroNCAP. The camera generates point clouds information in 3D format, which is acquired at a rate of 10 FPS (frames per second). The captured 3D data are stored and used as an input for the development in MATLAB/Simulink, where the identification algorithm is implemented. It locates the child target's position and determines the distance relative to the vehicle. Further, a decision-making system decides to activate the brakes according to their limits, avoiding collision with the target on one hand side and reducing false positive issues on the other hand side. In order to simulate the braking manoeuvre, the vehicle dynamic model is developed in a MATLAB/Simulink environment. Finally, the paper summarizes the advantages and disadvantages of the application of the proposed technology.

Estimation of the Impact of Human Body Variation on Its Crash Behavior Using Machine Learning Methods

F2020-PIF-051

PIF - Passive and Integral Safety

Mr. Franz Plaschkies, Technische Hochschule Ingolstadt / CARISSMA, GERMANY
Prof. Ondrej Vaculin, Technische Hochschule Ingolstadt, GERMANY

The capabilities of virtual development of safety systems for occupant safety are increasing with the growth of acceptance, computational power and the usability of tools. Nevertheless, nowadays car safety systems are primarily developed using single statistical representations of humans, like the 5%-ile female or the 50%-ile male body. Hence variation of anthropometry existing in the real-world is only covered to a very limited extent.

Recently, several studies developed fast calculating models using methods of rigid body simulation or metamodeling. They suggested investigating rapid or even near-real-time prediction-models for variations of outer parameters, such as airbag characteristics or crash pulse. In contrast, the proposed paper aims to get insight into the impact of human body variation on its crash behavior. This behavior can then be related to a model of a specific percentile. The objective of this approach is to run one simulation with a single representation of a human body and get data for deviated models based on previous simulations. Therefore, the main advantage of this concept is the reduction of the simulation time, needed to get all results of the occupants with different sizes (body mass index, statue, the ratio of sitting height and statue).

To test the feasibility of the approach, a 2D rigid body system was created as a simplified model using LS-Dyna and Python. It represents a car´s occupant who is restrained by a lap and shoulder belt under the influence of a crash pulse. The joint characteristics were modeled via spring, damper and friction definitions aiming for human-like behavior.

To create a database, extensive simulations were carried out by varying the dimensions of body parts, applying a Latin-Hypercube Design Of Experiments scheme. The parameter limits were taken from UMTRI´s human shape database. Since the minimal model provides a very limited set of reasonable assessment channels, only kinematic responses like maximum displacement and acceleration of the head and chest were evaluated.

The obtained results seem to prove expected correlations between mass and maximum acceleration as well as forward displacement. For the model´s training, different combinations of features and targets are tested. For example, the results from simulations with one body measure set are used as feature-vector, while the target-vector is formed by the kinematic characteristics of diverging human representations. After normalizing the data, various regression and machine learning algorithms were applied and their performance evaluated.

Experimental and Simulative Analysis of Tire Enveloping Characteristics Based on a Tire Measurement Database

F2020-VDC-011

VDC - Vehicle Dynamics and Controls

Dipl.-Ing. Yun Pang, Technische Universität Dresden, GERMANY
Dipl.-Ing. Tobias Schramm, Technische Universität Dresden, GERMANY
Dipl.-Ing. Jan Kubenz, Technische Universität Dresden, GERMANY
Prof. Dr.-Ing. Günther Prokop, Technische Universität Dresden, GERMANY

Coordinated Control of AFS and DYC for 4WID-EVS Handling and Stability Based on Driving State Prediction

F2020-VDC-042

VDC - Vehicle Dynamics and Controls

Dr. Cong Liu, Beijing Institute of Technology, CHINA
Prof. Dr. Hui Liu, Beijing Institute of Technology, CHINA

Considering that the driver's response was not timely under extreme conditions, and there was a time delay between the driver's behavior and the actuator, which would destabilize the vehicle. A coordinated control strategy based on driving state prediction was designed for improving 4WID-EVS lateral stability and handling performance through direct yaw moment control system (DYC) and active front steering (AFS). Firstly, the coordinated control strategy of AFS and DYC was designed, which consisted of two parts: (1) A stability judgeing method based on sideslip angle and sideslip angular velocity phase plane was proposed. The phase plane stability boundary coefficient was adjusted by the road adhesion coefficient, which divided the coordination control region reasonably, so as to judge whether the vehicle was unstable and switched the appropriate subsystem. (2) A driving state prediction algorithm based on data stream mining technology and Markov theory was proposed.

The fuzzy control theory which had good robustness was applied, the driving state in the future were made as the inputs, which could determine the weight coefficients of AFS and DYC in advance and effectively avoid the potential danger of entering the unstable state. Secondly, the nonlinear 3-dof vehicle model was used as the reference model, and AFS control strategy was designed based on model predictive control (MPC) theory. At the same time, in order to avoid no solution in the calculation process and improve the convergence speed of the solution process, the relaxation factor was introduced. The quadratic programming algorithm was adopted to find the optimal solution, so as to adjust the front wheel angle in real time to follow the desired path. In order to make up for the deficiency of AFS control strategy, the feedforward - feedback DYC control strategy was designed.

A variable weight coefficient LQR feedback control strategy was proposed, and the matrix weight coefficient could be adjusted in real time according to the vehicle steering state in the future and the road adhesion coefficient at the present. Finally, the accuracy and real-time of the prediction algorithm were verified according to different and actual driving cycle data. The simulation experiments of typical working conditions were carried out based on commercial dynamics simulation software to verify the effectiveness of the coordinated control strategy. The simulation results showed that the coordinated control method of AFS and DYC proposed had better effect of driving stability control, which provided a new method for the design of vehicle active safety.

KEY WORDS: distributed drive, coordination control, data stream mining, Markov, MPC

Validity Quantification of Driver-in-the-Loop Simulation in Motorsport

F2020-VDC-047

VDC - Vehicle Dynamics and Controls

Mr. Thomas Schwarzhuber, BMW Motorsport, GERMANY
Mr. Lukas Wörle, BMW Motorsport, GERMANY
Dr.-Ing. Michael Graf, BMW Motorsport, GERMANY
Prof. Arno Eichberger, Graz University of Technology, AUSTRIA

Driving simulators are indispensable tools to be competitive in motorsport, for drivers as well as engineers. Fidelity and validity of a driver-in-the-loop simulator determine its utility for car setup development, drivers’ training and race strategy investigations. The conclusions drawn from race preparations at a driving simulator take its validity at the vehicle’s dynamic limits as a basis.

A high level of simulator fidelity does not necessarily imply validity of research outcomes. Actuators, ergonomics and screen size as well as track model, vehicle model and motion cueing algorithms could influence simulator validity. Whereas the impact of track and vehicle model can be quantified, the impact of simulator motion on simulator validity is not yet holistically defined as objective data. Therefore, a method which quantifies the overall validity and the impact of individual simulator components is of high interest for further development.

The methodology to quantify simulator validity is based on driving style identification. A method was introduced earlier in our department to categorize race drivers, driving at the limit of a vehicle’s dynamic capabilities. From a motorsport engineer’s point of view the overarching objective of simulator development is to have minimum deviation in driving style between track and simulator tests. Race drivers’ driving style is defined, but not readily apparent, by their interactions with steering wheel and pedals. Recorded data of simulator and track operation is processed to calculate metrics during specific vehicle states. In this work the resulting driver metrics are further processed to driving style deviation metrics which describe discrepancies between race track and simulator operation. An evaluation of the derived metrics allows simulator validity quantification. The impact of motion stimuli on simulator validity is compiled using the introduced method to prove its relevance.

As a result, the here presented method serves as a measure of motorsport simulator validity. Additionally, the method allows to quantify driving style deviation at variable simulator setups. The impact of various simulator components on simulator validity can be analyzed consequently.

A limitation of the developed methodology is that the driver metrics are only validated for the classification of professional race drivers, driving the cars at the limit of their dynamic capabilities. Furthermore, validated track and vehicle models are mandatory requirements to evaluate the impact of motion stimuli on absolute validity of the simulator.

Knowledge about the impact of various components on simulator validity will provide objective guidance for future driving simulator development. In this particular case, research on evaluation and optimization of motion cueing algorithms will be carried out which is motivated by the obtained findings. Special focus will be on the motion stimuli while driving the simulated vehicle close to its dynamic limits.

Impact on the Quality of Automated Lateral Driving When Implementing an 2DOF Steering Model and Vary Driving Dynamic Quantities

F2020-VDC-070

VDC - Vehicle Dynamics and Controls

Mr. Julian Staiger, TU Delft, NETHERLANDS

Subjective Perception Prognosis of Divergent Data Sets of the Shift Strategy of Modern Dual-Clutch Transmissions on the Basis of Simulation Results

F2020-VDC-074

VDC - Vehicle Dynamics and Controls

Dipl.-Ing. John Köber, Karlsruhe Institute of Technology (KIT), IPEK - Institute of Product Engineering, GERMANY
Prof. Dr.-Ing. Albert Albers, Karlsruhe Institute of Technology (KIT), IPEK - Institute of Product Engineering, GERMANY
Paula Marta Jacobs, TU Braunschweig, GERMANY
Ercan Karakus, Hochschule Albstadt-Sigmaringen, GERMANY

The objectification of customer, user and supplier requirements in the development process is an important task to translate abstract requirements into the language of the product developers. However, this is particularly challenging in complex contexts, such as the adjustment of shift points of a transmission, since this system has a very strong interaction with the overall system. The subjective adjustment currently takes place very late in the development process, in the so-called hardware phase of the overall vehicle integration.

However, the adjustment and definition of the shift points of modern dual clutch transmissions is a fundamental part of today's vehicle developments. In particular, the subjective perception of the application engineers in the context of so-called driveability is decisive for the milestone release of data statuses in the automotive product development process. Currently, a large part of the application process, including the associated validation, is thus based on global test drives with physical prototype vehicles. Due to the necessity of prototype vehicles, this process can only take place at a correspondingly late stage in the product development process. This results in a rigid application and validation process that is very closely timed.

If subsequent changes to the data status are necessary after the very time-consuming and cost-intensive process, it is hardly possible to validate the resulting adjustments to the overall customer perception of the product. Thus, it can happen that vehicles are introduced to the market without final validation of the subjective drivability, or a cost-intensive postponement of this must be effected. Simulation models can be used to meet this discrepancy between the time requirements and the desire for sufficient validation.

On the basis of this motivation, this thesis deals with the question of how the subjective perception of drivability as a dependency of diverging application data of dual clutch transmissions can be predicted on the basis of simulation results.

First, possible influencing factors are identified which have the greatest influence on subjective perception in the context of the shift strategy. On the basis of a selected series data set, it is shown how it can be specifically adapted to achieve a sportier or more comfortable driving style depending on the factors identified. In order to measure the real influence on subjective perception, a test person study was then carried out, whereby the deviations of the adjusted data set from the series data set were always to be evaluated. In order to be able to use directly comparable results for the correlation analysis, the diverging data sets are simulated and evaluated with regard to their expected deviations from the series data set. Based on the simulation results and the statistical analysis of the test person study, a model is then developed to correlate time-dependent simulation data with subjective assessments of diverging data sets. This approach enables a prognosis to be made regarding the subjective perception of drivability.

Finally, a method for validation is presented, how this approach can be transferred to another vehicle segment with an alternative automatic transmission concept.

Development of Lateral Control for Different Electric Vehicle Drive and Steering Systems

F2020-VDC-075

VDC - Vehicle Dynamics and Controls

Dipl.-Ing. Amauri da Silva Junior, Technische Hochschule Ingolstadt, GERMANY
Prof. Dr.-Ing. Christian Birkner, Technische Hochschule Ingolstadt, GERMANY
Mr. Naveen Shirur, Technische Hochschule Ingolstadt, GERMANY

Design and Development Of An In-Wheel Suspension With Novel Automatic Camber Control Strategy For Improved Handling

F2020-VDC-081

VDC - Vehicle Dynamics and Controls

Mr. Sameer Rafiq Shah, University of Michigan - Dearborn, UNITED STATES
Mr. Dilip Kumar, Sir M. Visvesvaraya Institute of Technology, INDIA
Mr. Nishant Tiwari, Sir M. Visvesvaraya Institute of Technology, INDIA

Drive-by-Wire Vehicle Traction Control System with Predefined Safety Limits

F2020-VDC-089

VDC - Vehicle Dynamics and Controls

Ing. Denis Efremov, Czech Technical University in Prague, Faculty of Electrical Engineering, Department of Control Engineering, CZECH REPUBLIC
Dr.-Ing. Tomas Hanis, Czech Technical University in Prague, Faculty of Electrical Engineering, Department of Control Engineering, CZECH REPUBLIC
Ing. David Vosahlik, Czech Technical University in Prague, Faculty of Electrical Engineering, Department of Control Engineering, CZECH REPUBLIC
Dr.-Ing. Martin Klauco, Institute of Information Engineering, Automation, and Mathematics, Slovak University of Technology in Bratislava, SLOVAKIA

A drive-by-wire system seems to be a crucial technology for future road vehicles, including personal and commercial cars and urban road mobility platforms. The augmentation of human driving capabilities in the domain of maneuver safety and driving performance is beneficial. The most important benefit comes for autonomous driving, where the drive-by-wire represents technological enablers. The drive-by-wire architecture provides straight forward means of vehicle dynamics control system implementation. Mechatronics systems replace direct mechanical control links. Such a solution brings a possibility to change the inputs commanded by the driver according to the driving conditions.
The drive-by-wire vehicle dynamics control algorithm is proposed in this work, which helps the driver to steer, drive, and brake the car within predefined safety limits. The set of vehicle maneuvers represented by state values, where the vehicle wheels’ sliding motion stays in defined limits, is defined in previous work. This set is called the Driving Envelope (inspired by aerospace application, namely the flight envelope used for modern aircraft).

The safety limits of car maneuvers are represented by the Driving Envelop in vehicle states (speed, sideslip angle, and cornering speed in the center of gravity). The control system design protecting safety limits violation is presented in this work. The control functionality based on Model Predictive Control (MPC) approach, as both states and inputs constraints, are respected during optimization. The vehicle dynamics control system is denoted Driving Envelop Protection, again inspired by the flight control system and flight envelope protection functionality. The lateral vehicle dynamics is controlled using the MPC objective designed to track reference steering angle of the front axle commanded by the driver. The longitudinal vehicle dynamics is controlled based on wheel angular velocities of the front and rear axles, commanded from pedals. The optimization process is constrained by vehicle maneuver boundaries defined by the driving envelope. Hence, the car is protected from getting into a critical spin situation, wheel blocking, and loss of wheels’ traction.

The algorithm is validated using virtual ride tests on a simulator with an implemented high-fidelity twin-track model. During the experiments, an uncontrolled car was compared with the same but controlled vehicle on a couple of different maneuvers, including double-lane change tests, obstacle avoidance tests, and slalom ride tests.

Hybrid Approach to Identify Kinematic Points of a Suspension System

F2020-VDC-094

VDC - Vehicle Dynamics and Controls

Dipl.-Ing. Clemens Deubel, Chair of Automobile Engineering - Technische Universität Dresden, GERMANY
Mr. Peter Hoffmann, Technische Universität Dresden, GERMANY
Mr. Chao Liu, Chair of Automobile Engineering - Technische Universität Dresden, GERMANY
Dipl.-Ing. Jan Kubenz, Chair of Automobile Engineering - Technische Universität Dresden, GERMANY
Prof. Dr.-Ing. Günther Prokop, Chair of Automobile Engineering - Technische Universität Dresden, GERMANY

A Real-Time and Calibration-Free Lane Departure Warning System for AUTOSAR-Based ECUs

F2020-VES-002

VES - Vehicle Electronics and Software

Mr. Islam Gamal, Mentor Graphics, EGYPT
Mr. Ahmed Hamed, Mentor Graphics, EGYPT

I. THE PROPOSED ALGORITHM
A real-time, calibration-free and AUTOSAR-compliant lane departure warning system algorithm is proposed. First, the region of interest (ROI) is extracted to reduce the outlier lines in the image. Then, pre-processing stage is carried out using Gaussian pyramid to smooth the image and reduce its dimensions, which decrease the unnecessary details in the image. A lane detection stage is then developed based on Edge Drawing Lines (EDLines) algorithm that is a real-time line segment detector, which has false detection control. After that, basic machine learning (ML) concepts are employed in the lane filtering and clustering stage to reject the lines with low probability of being lane boundaries. Based on these lines, an advanced reference-counting algorithm is introduced to track the lanes, between consecutive frames taken by a single front camera, and predict the missing lanes.

II. EXPERIMENTAL RESULTS
According to ISO 17361:2017 standard, the environment conditions required to test LDWS are flat and dry asphalt, lane markings are directly visible by the driver and horizontal visibility range shall be greater than 1 km. The stated conditions in the standard describe an ideal environment, but real life is not ideal. To guarantee that the driver safety is accomplished by our system, the system is tested by a various challenging weather and illumination conditions: clear, cloudy, rainy, day, sunset and night. ISO 17361:2017 standard tests, which are Warning generation in a curve, Repeatability and False alarm, are also performed on the proposed system successfully. The proposed system achieves detection rate of 99.41%, departure rate of 100% and average processing time of 100 milliseconds milliseconds on ECU with TC397 microcontroller up to 300 MHz and 6.9 MB RAM.

III. CONCLUSIONS
Calibration phase consumes a lot of time and effort for getting its knowledge, configuring calibration modules and performing the calibration itself to the system parameters. In addition, calibration process costs a lot of money for buying both calibration tools and AUTOSAR XCP calibration module.
In this paper, a new reliable and robust algorithm to implement an LDWS that is AUTOSAR-compliant and do not require calibration, as it does not have parameters that need to be tuned and adjusted to make the system work properly, is introduced. Hence, the proposed system saves time, effort and money required by calibration process. Moreover, it is efficient to be used in the self-driving systems in the Original Equipment Manufacturers (OEMs) cars that are composed of either AUTOSAR-based or non-AUTOSAR-based ECUs

Procedure for the Safety Assessment of an Autonomous Vehicle Using Real-World Scenarios

F2020-VES-014

VES - Vehicle Electronics and Software

Mr. Erwin de Gelder, TNO, NETHERLANDS
Dr. Olaf Op den Camp, TNO, NETHERLANDS

The development of Autonomous Vehicles (AVs) has made significant progress in the last years and it is expected that AVs will soon be introduced on our roads. An important aspect in the development of AVs is the assessment of their safety. As traditional methods for safety assessment of vehicles are not feasible to be performed for AVs within reasonable time and cost, new approaches need to be worked out. Among these, real-world scenario-based assessment is widely supported by many players in the automotive field. Scenario-based assessment allows for using virtual simulation tools in addition to physical tests, such as on a test track, proving ground, or public road.

We propose a procedure for real-world scenario-based road-approval assessment considering three stakeholders: the applicant, the assessor, and the (road or vehicle) authority. In this procedure, the applicant applies for the approval of one specific AV, the assessor assesses this AV and advises the authority, and the authority sets the requirements for the AV and decides whether this specific AV is approved for road testing The challenges are as follows. Firstly, the tests need to be tailored to the operational design domain (ODD) and dynamic driving task (DDT) description of the AV. Secondly, it is assumed that the applicant does not want to disclose all of the detailed test results because of proprietary or confidential information contained in these results. Thirdly, due to the complex ODD and DDT, many test scenarios are required to obtain sufficient confidence in the assessment of the AV. Consequently, it is assumed that due to limited resources, it is infeasible for the assessor to conduct all (physical) tests.

We propose a systematic approach for determining the tests that are based on the requirements set by the authority and the AV’s ODD and DDT description, such that the tests are tailored to the applicable ODD and DDT. Each test comes with metrics that enables the applicant to provide a performance rating of the AV for each of the tests. By only providing a performance rating for each test, the applicant does not need to disclose the details of the test results. In our proposed procedure, the assessor only conducts a limited number of tests. The main purpose of these tests is to verify the fidelity of the results provided by the applicant. Still, the applicant needs to conduct many tests, but this is assumed to be feasible because the applicant can utilize virtual simulation tools to conduct (a part of) the tests whereas this is not possible for the assessor due to proprietary or confidential information. To illustrate the proposed procedure, an example is presented.

Agile Software Design Verification and Validation (V&V) for Automated Driving

F2020-VES-017

VES - Vehicle Electronics and Software

Dr. Yixiao Li, Nagoya University, JAPAN
Prof. Dr. Yutaka Matsubara, Nagoya University, JAPAN
Mr. Daniel Olbrys, Toyota Research Institute - Advanced Development, Inc., UNITED STATES
Mr. Kazuhiro Kajio, Toyota Research Institute - Advanced Development, Inc., JAPAN
Mr. Takashi Inada, Toyota Research Institute - Advanced Development, Inc., JAPAN
Prof. Dr. Hiroaki Takada, Nagoya University, JAPAN

A STPA-based Approach for Systematic Security Analysis of In-vehicle Diagnostic and Software Update Systems

F2020-VES-020

VES - Vehicle Electronics and Software

Jinghua Yu, Tongji University, CHINA
Prof. Dr. Stefan Wagner, University of Stuttgart, GERMANY
Prof. Dr. Feng Luo, Tongji University, CHINA

With the continuing innovations in the safety and intelligence of automobiles, the connectivity of vehicles increases which comes with also increasing security challenges. The in-vehicle diagnostics and software update system, which is an essential part of modern vehicles that supports remote diagnostics and Over-The-Air (OTA) firmware or configuration updates, is a common attack goal in automobiles. Adversaries can inject malicious software into vehicles or steal sensitive information through in-vehicle channels. Therefore, security needs to be considered during system design. Security analysis discusses potential security issues and derives related items, like threats, risk assessment and constraints, to guide secure design.

However, all security analyses of such an in-vehicle system are threats-oriented, which start from threat identification and assess risks of identified threats. In this paper, a top-down system-oriented approach is proposed on the basis of the System-Theoretic Process Analysis (STPA) approaches, which are a set of hazard analysis techniques based on the System-Theoretic Accident Model and Processes (STAMP). Since constructing control structures is an essential step in the STPA approaches, it is hard to apply STPA to systems with few control actions and a strong focus on data flows. The proposed approach extends the original STPA from the perspective of data flows and is applicable for software-intensive or data-flow-based systems.

We propose an abstract system model of in-vehicle diagnostics and software update systems and use it to propose a security analysis guideline. We identify losses, hazards, insecure function behaviours and loss scenarios of this class of systems to support concrete analyses and present an example case.

Comparing with other threat-oriented approaches, the STPA-based approach shifts from focusing on threats to system vulnerabilities. The former cannot be controlled by system designers, but the latter can. The proposed approach provides a new perspective for recognizing system and security issues and is efficient to prevent the system from known or even unknown threats.

Furthermore, the STPA approaches have been proved to be suitable for high-level systems, like socio-technical systems, and applicable for various fields, including safety, security and privacy. As an extension of the STPA approaches, the proposed one can be well integrated into the analysis at a higher level and perform a co-analysis of vehicle systems between safety and security with a unified analysis framework.

Programme

Organised by

Paper Theme

Company

Research on System Identification of Vehicle Model for Model Based Reinforcement Learning Automated Parking

F2020-ACM-004

Coupling Apollo with the CommonRoad Motion Planning Framework

F2020-ACM-019

Positioning Sensor System for Transmodular Mobility

F2020-ACM-042

Human vs. Automation - Who Drives the Future?

F2020-ACM-044

Assessing the Readiness of Infrastructure for Automated Vehicles from a Safety Perspective

F2020-ACM-065

Evaluating Autonomous Functions Performance Through Simulation Using Interoperable Sensor, Vehicle, and Environment Models

F2020-ACM-067

Real-time Trajectory Planning and Vehicle Control for Automated Turning Traveling to the Specified Exit Point

F2020-ACM-069

Methodology for Automated Definition of Critical Scenarios

F2020-ACM-073

Sensor Time Synchronization in Smart Road Infrastructure

F2020-ACM-083

Scenario Based Testing of Automated Driving Systems: A Literature Survey

F2020-ACM-096

Research on Electromagnetic Vibration and Noise Characteristics of Double-rotor Permanent Magnet Synchronous In-wheel Motor

F2020-ADM-030

Raising the Thermal Limits of an Electrical Motor Based on an Air Gap Winding by Applying Improved Laminated Layers and Optimized Cooling Duct Geometries

F2020-ADM-040

Efficient commercial powertrains – How to achieve a 30% GHG reduction in 2030

F2020-ADM-054

Combined Cycle Gas Turbine System Optimization for Extended Range Electric Vehicles

F2020-ADM-055

Capacity Characteristics Analysis and Remaining Useful Life Estimation Method of Ternary Lithium Battery Pack

F2020-ADM-060

Application of PM Gearset in Automotive Gearbox

F2020-ADM-069

A New Engine Concept to Control the Ignition Timing of HCCI Combustion: Piston Assisted Compression Ignition (PACI)

F2020-ADM-073

The New Solutions of Energy Utilization of the Exhaust Gases of the Internal Combustion Engines Through Hybrid Turbochargers

F2020-ADM-081

Dog Clutch Without Circular Backlash – Design Optimization Using Multi-Body Simulationx

F2020-ADM-083

Suitability of Using Electric Vehicles in Asia Countries

F2020-ADM-085

Data-Based Parameterization of Thermal Models of a Gearbox

F2020-ADM-126

Improving Efficiency and Power Density of Hydrogen Engines of Positive Ignition Single-Fuel and Compression Ignition Dual-Fuel designs

F2020-CAF-001

Fluid Dynamics Analysis of Bubble Generation Process in Engine Oil Based on Model Experiments

F2020-CAF-007

Customer-Focussed Automatic Test Course Design

F2020-DGT-007

upBUS – Electrical, autonomous driving, transmodular bus for public transport systems

F2020-DGT-012

New Approaches to Digitalizing the Design and Validation Process of Complex Mount Bearings with the Focus on Durability

F2020-DGT-016

A Method for User-Friendly PID-Parameter Optimization for Highly Dynamic Component Test Benches

F2020-DGT-031

Optimization Design of Large-displacement Motorcycle Emission Testing Procedures

F2020-EPV-014

Analytical Investigation of Tire Induced Particle Emissions

F2020-EPV-027

High Fuel Pressure and Multiple Injection of Gasoline for the Particle Emission Reduction Under Cold Conditions

F2020-EPV-028

Real-Time Torque Estimation of an Air Conditioner Compressor for the CO2 Emissions Reduction from an Engine Vehicle

F2020-EPV-071

The Control Strategy Research on Reduction of High-Frequency Noise and Vibration for Permanent Magnet Synchronous Motor

F2020-MCF-002

Vibration Transmissibility Analyses of Asymmetric Cantilevered Structures with Screw Fastening by Mode Equivalent Factors

F2020-MCF-006

Start-Up Transient Vibration Analysis and Control of a Vehicle Equipped with a 3-Cylinered Engine

F2020-MCF-012

Factors Affecting Squeak Characteristics of Plastic Parts And Its Prevention Solutions

F2020-MCF-020

Study and Reduce the Interior Noise Roughness During Acceleration

F2020-MCF-057

Vibro-Acoustic Reciprocity Analysis Using Dodecahedral Sound Source and its Application for Material Assessment

F2020-MCF-062

Vibration Behavior of Powertrain Test Benches - Measurement, Analysis and Modelling

F2020-MCF-066