Linear-Quadratic Tracking Control of a Commercial Vehicle Air Brake System

Abstract

This paper proposes to utilize linear-quadratic tracking (LQT) control to reduce the air brake system response time and vehicle stopping distance, and hence, to significantly improve the system performance of a commercial vehicle air brake system equipped with electro-pneumatic proportional valve actuators. The nonlinear dynamic model of the air brake system, consisting of a control actuator (a proportional valve) and braking actuator (the brake chamber), is developed and linearized using the q-Markov COVariance Equivalent Realization (q-Markov Cover) method in our early work. Based on the linearized dynamic model, an infinite horizon LQT controller is designed along with Kalman state estimation at each linearized operational condition. To apply the LQT control law over a wide operational range to track the target pressure, the designed controller was interpolated between the neighboring controllers to have a control law cover the entire operational range. To validate this control law, the control scheme is implemented into a dSPACE unit and validated through bench tests under different supply and reference pressures. The LQT control performance is also compared with the PID (proportional-integralderivative) one. The bench test results confirm the effectiveness of the proposed control scheme.

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

“…The research of APRV has mainly focused on the control strategy and electric circuit. Hu Dawei et al proposed the MPC, LQT and LPV control models in order to reduce the response time of the pressure regulating valve in the ECPBS of commercial vehicles, which was verified by the test bench and compared with the data of a PID control model, thus effectively improving the response speed of the pressure-regulating valve and the performance of the ECPBS of commercial vehicles [14][15][16]. Bin Zhang et al, proposed a self-correcting PWM control algorithm for high-speed on/off valves to maintain and improve the original dynamic performance under changing pressures [17].…”