In order to improve the braking performance and safety performance of electric vehicles driven by a hub motor, the cylinder pressure estimation and pressure control of its hydraulic braking system are studied. In this paper, a mathematical model is established for the solenoid valve, a key component of the hydraulic actuator, and the hydraulic and electrical characteristics of the solenoid valve are studied. A state equation is established for the solenoid valve, and the square root volume Kalman filter (SRCKF) algorithm is used to estimate the solenoid valve spool position. The brake fluid flow and brake wheel cylinder pressure are calculated based on the spool position. Finally, a solenoid valve spool position control algorithm based on sliding mode variable structure algorithm is designed, and the brake pressure in the brake wheel cylinder is controlled by adjusting the spool position. Matlab/Simulink-AMESim software simulation and hardware-in-the-loop were used to verify the algorithm. Simulation results show that the brake cylinder pressure can be estimated accurately, and the pressure control algorithm can accurately follow the control target value.

中文翻译：

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电动轮车液压控制单元的压力估算和压力控制

为了提高由轮毂电动机驱动的电动汽车的制动性能和安全性能，研究了其液压制动系统的气缸压力估计和压力控制。本文建立了电磁阀的数学模型，液压执行器的关键部件，并对电磁阀的液压和电气特性进行了研究。建立电磁阀的状态方程，并使用平方根体积卡尔曼滤波器（SRCKF）算法估算电磁阀滑阀位置。根据阀芯位置计算出制动液流量和制动轮缸压力。最后，设计了一种基于滑模变结构算法的电磁阀滑阀位置控制算法，并通过调节阀芯位置来控制制动分泵中的制动压力。使用Matlab / Simulink-AMESim软件仿真和硬件在环验证了该算法。仿真结果表明，可以准确地估计制动缸压力，并且压力控制算法可以准确地遵循控制目标值。