关键词: 车辆动力学, 液压执行单元, 平方根容积卡尔曼滤波, 滑模控制算法, 硬件在环试验

Abstract: In order to enhance the braking and safety performances of hub motor-driven electric vehicle, the estimation and control of cylinder pressure in hydraulic braking system are studied. Firstly, a mathematical model for the loop control valve of key component in hydraulic actuation unit is established to analyze its hydraulic and electrical characteristics. Then the state equation for the loop solenoid valve is set up by using square root cubature Kalman filtering algorithm, to estimate the lift of solenoid valve and hence accurately calculate the current flow rate of brake fluid and the pressure in wheel cylinder. Next, according to the p-V characteristics, the control algorithm of solenoid valve lift is designed based on sliding mode variable structure algorithm, so the braking pressure in wheel cylinder can be controlled by adjusting the lift of solenoid valve. Finally, both Matlab/Simulink-AMESim co-simulation and hardware-in-the-loop test are conducted to verify the algorithms adopted. The results show that the proposed algorithm for the estimation and control of cylinder pressure in hydraulic braking system can accurately follow the control target value, enhancing the braking performance of hub motor-driven electric vehicle

Key words: vehicle dynamics; hydraulic actuation unit; square root cubature Kalman filtering; sliding mode control algorithm; hardware-in-the-loop test