Abstract: The caliper braking force is the fundamental signal of the electronic mechanical braking system(EMB), and its accurate estimation is one of the core technologies of EMB. However, under anti lock braking(ABS) conditions, the caliper braking force exhibits high-frequency and large fluctuation characteristics, and conventional estimation methods are difficult to simultaneously meet the requirements of response speed and accuracy. In response to this issue, this paper proposes a high-speed motion clamp force estimation method based on corrected extended Kalman filter(C-EKF), and its effectiveness is verified through real vehicle testing. Firstly, establish a physical model of the EMB motor and caliper, and combine the braking force stroke data from actual vehicle testing to construct a force displacement fitting curve for the clamping and releasing process of the caliper. Secondly, analyze the characteristics of braking force changes at the moment of clamping and releasing under ABS working conditions, provide a calculation formula for instantaneous braking force changes, and estimate the braking force using the C-EKF method. Finally, the effectiveness of the method was verified through simulation and real vehicle testing. The experimental results show that the braking force estimation accuracy based on C-EKF has improved by 12.93% and 5.99% compared to Kalman filter(KF) and extended Kalman filter(EKF), respectively, and the response time has been shortened by 36.3 ms and 10.3 ms, respectively.

Key words: electromechanical brake, brake force estimation, extended Kalman filter, anti-lock braking control, vehicle dynamics