Braking systems development is currently facing a shift in the engineering and testing activities. Traditionally pedal feel tuning and performance refinement have been major issues, but along with electrification, the increasing level of driving automation is shifting development efforts into different directions. For a brake system, the task of autonomous driving (with or without human presence) mandates redundancy in many subsystem elements. Therefore, a strong effort in understanding how to set targets is needed to correctly develop and validate reliable systems. In this paper, the authors are initially defining a set of performance key factors, which will be used to define the global characteristics of the system. It is not necessary to deeply investigate the performance of the system to validate the operation of a vehicle equipped with a redundant braking system, but in the concept phase it is certainly useful to investigate how different architectures could potentially influence the vehicle performance. Having investigated the structure of the system, the authors suggest how targets could be set for a vehicle equipped with a redundant braking system. This study is mainly focused on understanding and validating how failures affect the general performance of the vehicle. Primarily this paper shows how partial system failures (ESP, EPB, iBooster) affect the general braking performance, mainly in terms of deceleration, stopping distance, front/rear modulation, on slope braking performance and finally time-to-lock. The main output of this study is the definition of a validation matrix (a so called Design Validation Plan), which is certainly a necessary step in order to perform a robust Vehicle Target Setting (VTS). A list of metrics is also proposed by the authors. The target book generation needs to be as versatile as possible, in order to be adapted to the full range of available systems in the market, particularly when the systems allow automated driving levels higher than L3.
BrakeBetter: Mr. Deaglán Ó Meachair; Applus IDIADA: Ing. Fabio Squadrani, Mr. Carlos Joe Sierra, Mr. Gerard Perez, Mr. Jeremie Clement, Mr. Narcis Molina