Abstract:

The technological development trend of intelligent and electrified commercial vehicles puts forward higher requirements for the pressure dynamic control effect of its braking system. Overshoot in the pressure control process can easily cause frequent switching of control modes， which ultimately affects the braking safety of the vehicle. This paper takes the new generation of axle modulator as the research object， focuses on the analysis of the dynamic characteristics of its pilot chamber pressure and brake chamber pressure， and proposes a multi-mode pressure tracking control method based on the rapid pressure build-up characteristics of the pilot chamber. This method tracks and controls the brake chamber pressure according to the pressure state in the pilot chamber when the system needs to be rapidly pressurized， thus effectively avoiding the problem that the response speed and control accuracy of the traditional PID controller are difficult to balance. This paper first uses Matlab/Simulink to model the system， focusing on the analysis of the dynamic relationship between the pressure of the pilot chamber and the pressure of the brake chamber. Secondly， a multi-mode pressure tracking control method of axle modulator based on pilot chamber pressure estimation is proposed. Finally， the model verification test and pressure tracking test are completed through the hardware-in-the-loop test bench based on dSPACE. The test results verify the effectiveness of the control method proposed in this paper. Compared with the traditional PID controller， the control method proposed in this paper effectively improves the pressure tracking dynamic control effect， and it is convenient for engineering application.

Key words: electronic braking system of commercial vehicle, pilot chamber, multi-mode pressure tracking control, bench test