A Control-Oriented Linear Parameter-Varying Model of a Commercial Vehicle Air Brake System

Abstract

<jats:p>This paper presents a control-oriented LPV (Linear Parameter-Varying) model for commercial vehicle air brake systems, where a pneumatic valve actuator is used to control the brake chamber pressure. To improve the brake system response time and reduce the vehicle stopping distance, the traditional treadle valves used in the air brake system are replaced by electro-pneumatic valves. Also, to develop the model-based brake control strategy, a nonlinear mathematical model is developed based on Newton’s second law, fluid dynamics of the orifice, force balance of spool, and solenoid dynamic characteristics. The brake chamber dynamics is also considered during the charging and discharging processes. The developed nonlinear model is calibrated based on both valve actuator geometry and test bench experimental results. It is proposed to model the nonlinear system in the LPV form so that gain-scheduling controllers can be developed. To obtain the LPV model, system identification is conducted using the calibrated nonlinear model to obtain a set of linearized models under different brake chamber pressure levels, and the resulting identified linear models are assembled to form the LPV model with brake chamber pressure as the varying parameters. A linear infinite-horizon continuous-time LQR (Linear Quadratic Regulator) controller was designed for the braking system based on the developed LPV model with the fixed parameter to demonstrate the effectiveness of the developed LPV model.</jats:p>

Gain-Scheduled Model Predictive Control for a Commercial Vehicle Air Brake System

“…Through Newton's second law, fluid dynamics, and the ideal gas state equations, a nonlinear mathematical model from the input voltage signal to the output pressure in the brake chamber was established, as shown in Equation ( 2) below. The detailed modeling process can be found in [26].…”

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

“…Finally, the entire nonlinear mathematical model architecture is shown in Figure 6. The details of the modeling process can be found in our early work [28].…”

“…The main contributions of this paper are three-fold: a) the LQT controllers are designed based on the Linear Parameter-Varying (LPV) model of the air brake system with the proportional valve to improve the performance of the system at each operating point, where the detailed modeling work is shown in our early work [28]; b) the designed controllers are interpolated to cover the entire operating range; and c) the interpreted LQT controller is validated on a test bench and the simulation and experimental results are compared with that of the PID controller.…”

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

“…A good pressure regulation method can ensure that the APRV can meet the braking requirements of various working conditions. Therefore, study of the pressure regulation method of APRV is of great significance for the safety and comfort of commercial vehicle braking [2].…”