Study on the Structural Configurations and Pressure Regulation Characteristics of the Automatic Pressure Regulating Valve in the Electronically Controlled Pneumatic Brake System of Commercial Vehicles

Abstract

Based on the classification of automated driving by the SAE (Society of Automotive Engineers) and the working principle of the ECPBS (Electronically Controlled Pneumatic Brake system), the requirements and the control modes of the APRV (Automatic Pressure Regulating Valve) were concluded. Four structural configurations for APRV were proposed to meet the requirements of the ECPBS. To study the pressure regulating characteristics of the APRV of different structure configurations, a simulation model was established, and a test bench was built. Through experiments, the correctness and the reliability of the simulation model were verified. The pressure regulation characteristics of the APRV of different structure configurations under different control conditions were revealed, and the suitable levels in the SAE automated driving classifications for automatic pressure regulators of different structure configurations were determined; thus, the theoretical underpinning to improve driving safety and develop automated driving was provided.

Study on the Pressure Regulation Method of New Automatic Pressure Regulating Valve in the Electronically Controlled Pneumatic Brake Systems in Commercial Vehicles

“…After processing the information, the decision-making layer generates a control signal for the ECPBS and realizes the real-time monitoring and control of the braking process [17]. Figure 1 is the principle drawing of the ECPBS for driving automation in commercial vehicles [3]. It can be seen from the figure that the APRV is installed in the front of each wheel brake chamber.…”

“…In addition, it must also be able to complete braking when the electronic control fails. Figure 2 shows the LF-APRV, which is composed of high-speed switching valve, high-speed inlet valve, high-speed exhaust valve, and relay valve [3]. The high-speed switching valve can realize the switching of two gas circuits.…”

“…The forces on the piston are the gas pressure on the upper and lower surfaces of the piston, friction force, and viscous damping force. The piston motion equation [3] is as follows:…”

“…Therefore, the study of the pressure regulation methods for the APRV has mainly focused on the control method of the highspeed solenoid valve. Hanwei Bao et al [3], based on a functional analysis of the ECPBS in commercial vehicles, put forward four different structures for the APRV. After comparing the pressure response characteristics of the four APRV structures, the structure with the best performance was determined.…”

Highly Redundant Safety Scheme and its Experimental Validation for the Electronic-Controlled Pneumatic Braking System of Commercial Vehicle for Autonomous Driving

“…Simulation results showcased effective fault diagnosis of the differential braking system, enhancing vehicle active safety. Bao H [17][18][19][20] designed an electronically controlled air pressure braking system with an automatic pressure regulating valve for commercial vehicles targeted at driving automation. Through comparative structural analysis via simulation and experiments, they verified that the electronically controlled, human-independent decoupling structure of the automatic pressure regulating valve effectively enhances braking safety and reliability, meeting both commercial vehicle braking requirements and the needs of autonomous driving.…”