Design and Experiment of Control Architecture and Adaptive Dual-Loop Controller for Brake-by-Wire System With an Electric Booster

Abstract

Brake-by-wire (BBW) is a critical technology in modern automotive and lays a solid foundation for intelligent vehicles. A control strategy to take full advantage of this system both in the active brake and the conventional boosting brake is essential for the BBW system, which is a challenging issue because of its complex structure and high requirement for rapid dynamic response and control accuracy. To get satisfying performance and control effect, this article designs a new type of electric booster installing on the electrohydraulic brake (EHB) system that can realize active brake control and brake boosting simultaneously, and then, a synthetic control architecture special for this system is put forward. First, the system principle and detailed modeling are given. Then, an adaptive dual-loop brake pressure control approach is proposed where a modified PID controller is used as the outer control loop to track the desired pressure and an inner loop named adaptive current control is employed to guarantee the brushless direct electric motor (BLDC) performance of tracking current considering the parametric variation and system uncertainties. Besides, the stability of the inner loop control is proven. Meanwhile, a user-defined brake-boosting framework is designed to realize the electric boosting brake. Simulation and experimental validation are implemented to demonstrate the feasibility of the system and the effectiveness of the control strategy design eventually, manifesting that the proposed BBW system and its control strategy can obtain satisfying performance.