Research on Full Brake-By-Wire System and Clamping Force Estimation Strategy Based on Redundant Drive Motors

In this study, a full brake-by-wire system with a dual-drive motor as a redundant power source and a planetary roller screw (PRSM) as a motion conversion mechanism is proposed for automated driving and wire-controlled chassis. Its parameters are matched, and the prototype is trial-produced. Aiming at the proposed full brake-by-wire system, a clamping force estimation control strategy is proposed that comprehensively considers electric caliper dynamics, stiffness, and friction models. In particular, considering the influence of motor temperature on the output torque, a temperature estimation model based on the proximal policy optimization-reinforcement learning (PPO-RL) algorithm was proposed, which was proven to effectively predict the motor temperature with an average error of only 1.06%. Finally, a hardware-in-the-loop test was performed, and the experimental results verified the effectiveness and superiority of the proposed system and control strategy, with a fast response, good clamping force continuous-following effect, and high clamping force estimation accuracy.