top of page
This paper describes a new holistic motion control approach for personalized and efficient vehicle dynamics. The control system is part of Continental’s Holistic Driverless Technologies and contributes to the Program Autonomous Driving making cars intelligent and driving safer than ever before. The goals and use-case scenarios of the key functionalities, the logical architecture and the common interface structure leading to best reusability of existing system elements will be presented in the paper. An object oriented design pattern maps the overall system into parent and child systems along different chain of effects. The chains are either build for specific purposes or represent emergent properties like waste heat. Examples of parent/child system pairs are vehicle/chassis, chassis/corner or corner/actuator. Each system distinguishes internally between information providers (observer functions) and managers. Observer functions provide information for the own and the parent level and coordinate limits received from the child level. Manager functions determine requests to control the respective child system. The application of holistic motion control is demonstrated using the example of an electric vehicle with wheel individual electric motors at the front axle and friction brakes at each corner. Vehicle level longitudinal and lateral requests are determined by a dynamic feedforward control with personalizable vehicle responsiveness and damping characteristics. The central element on chassis level is a Model Predictive Controller (MPC) requesting corner module forces while accounting for limits of stability and energy. A twin track model is used to describe the dynamics of the chassis. Time variant system matrices are generated by linearization and discretization at every sampling instant. Tire-road friction circles constraining the admissible forces at the wheels are approximated by polygons. The purpose of these measures is to ensure the applicability of convex quadratic programming suitable for real time embedded optimization. Corner modules process the incoming stream of chassis requests and generate a stream of requests to the actuators. A corner module MPC framework at the front axle is able to optimally split the wheel braking torque among the redundant actuators, while providing anti-lock braking features by wheel slip regulation. This approach offers fast transient response, without compromising the energy recuperation efficiency of the electric motors taking different dynamic authorities of friction brake and electric motor into account. Continental is aware of its responsibilities in the transformation of mobility and energy efficiency and has actively taken up the challenges. In doing so, we are paving the way to deliver intelligent and sustainable mobility far into the future, while at the same time making a significant contribution to maintaining the attractiveness of personal mobility.
Dr.-Ing. Thomas Raste, Continental AG, GERMANY Dr.-Ing. Andree Hohm, Continental AG, GERMANY Dipl.-Ing. Alfred Eckert, Continental AG, GERMANY