Pneumatic booster regulators (PBR) are in great demand in modern pneumatic systems for their energy-saving abilities. A new booster regulator with energy recovery (VBA-R) was proposed, and its energy efficiency was investigated by introducing the concept of air power. On the basis of quality-alterable gas thermodynamics, an energy efficiency assessment and pressure response model for VBA-R was proposed. First, a model was solved using MATLAB/Simulink software, and an alternative experiment was designed to verify the mathematical model and performance improvement. The results showed that the simulation was consistent with the experiment. We also can conclude that, first of all, the energy efficiency decreases with the increasing of supply pressure and flow-rate consumption; a VBA-R has the highest efficiency when its diameter ratio is closest to 1.3. Finally, a recovery chamber helped to improve the performance of the VBA-R, which included a boost ratio improvement of 15–25% and an efficiency improvement of 5–10% compared with a conventional VBA booster regulator. This research lays the foundation for optimism regarding the proposed booster regulator.

This study aims to propose an analysis method for resolving the pressure response of a pneumatic brake circuit considering the effect of a transmission pipe. Pneumatic brake systems (PBS) are widely used in commercial vehicles. The pressure response characteristic of the PBS is the key factor affecting braking performance. By using the thermodynamics of a variable-quality system, the pressure response model of the brake chamber is established, which includes the dynamic model of the pipe considering the unsteady friction and heat transfer. The partial-differential control equations of pipe are solved by introducing the constrained interpolation profile (CIP) method, and a virtual chamber model is proposed to set the boundary condition so as to solve the pressure response in the brake chamber simultaneously. Thus, the regularity of the brake pressure response is obtained by considering the influence of the pipe. Lastly, the model is verified experimentally. The present study indicates that the main factors that affect the pressure response delay are the pipe length and the combination forms of the sonic conductances of the orifices inlet and outlet. Furthermore, it helps to verify that the CIP method is an effective way of solving the pressure response of a brake circuit because of its high accuracy. The present study serves as a foundation for the design and analysis of a PBS.

In order to adapt the development of vehicle driving automation technology for driving conditions under different levels of automation and based on the independently invented LF automatic pressure regulating valve (LF-APRV) for electronically controlled pneumatic brake systems (ECPBS), the dynamic PWM coupling pressure regulation method is proposed. This method realizes pressure regulation by adjusting the duty cycle of the control signal of the LF-APRV at different stages in the pressure regulation cycle. A co-simulation model was established to verify the feasibility of the method, and a test system was built to verify the correctness of the co-simulation model. Through the test, the pressure regulation performance of dynamic PWM coupling pressure regulation method and conventional on/off pressure regulation method was compared. The results show that the new method can improve the stability of pressure regulation, although the response time increases; under the new method, the overshoot of the pressure rising from 0 to 0.5 MPa was reduced by 69%, and the overshoot of the pressure decreasing from 0.5 MPa to 0.2 MPa was basically 0. Finally, tests and simulations showed that the dynamic PWM coupling pressure regulation method can meet the continuous graded braking requirements of vehicles, and the pressure response has good tracking performance on the target pressure.

This paper presents a control-oriented Linear Parameter-Varying (LPV) model for commercial vehicle air brake systems with the electro-pneumatic proportional valve based on the nonlinear mathematical model, a set of discrete-time linearized models at different target pressures with the q-Markov Cover system identification method. The scheduled parameters for the LPV model were the brake chamber pressure, which was controlled by the electro-pneumatic proportional valve. On the basis of the LPV model, a family of Model Predictive Control (MPC) controllers with a Kalman filter was designed at each operation point. Then, the gain-scheduled MPC was designed over the entire operating range with the switched strategy, which was validated by experimental data. Furthermore, compared with the PID controller, the performance of the system was improved with a gain-scheduled MPC controller.

In contrast to the traditional pneumatic braking system, the electronic-controlled pneumatic braking system of commercial vehicles is a new system and can remedy the defects of the conventional braking system, such as long response time and low control accuracy. Additionally, it can adapt to the needs and development of autonomous driving. As the key pressure regulating component in electronic-controlled pneumatic braking system of commercial vehicles, automatic pressure regulating valves can quickly and accurately control the braking pressure in real time through an electronic control method. By aiming at improving driving comfort on the premise of ensuring braking security, this paper took the automatic pressure regulating valve as the research object and studied the pressure change rate during the braking process. First, the characteristics of the automatic pressure regulating valve and the concept of the pressure change rate were elaborated. Then, with the volume change of automatic pressure regulating valve in consideration, the mathematical model based on gas dynamics and the association model between pressure change rate and vehicle dynamic model was established in MATLAB/Simulink and analyzed. Next, through the experimental test of a sample product, the mathematical models have been verified. Finally, the key structure parameters affecting the pressure change rate of the automatic pressure regulating valve and the influence law have been identified; therefore, appropriate design advice and theoretical support have been provided to improve driving comfort.

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.