重车联合制动电液比例控制系统仿真与实验研究

根据重型车辆联合制动电液比例控制系统的组成和工作特性，分析了其主要控制元件电液比例／伺服减压阀的数学模型，建立了比例／伺服阀控制制动缸系统的非线性数学模型，并给出了制动系统的线性化传递函数；根据所选的具体比例阀特性和系统参数，计算了液压固有频率和PID闭环系统特性。分别进行了闭环系统数字仿真计算、控制系统台架试验和某50 t重型车辆的实际控制试验，三者的数据基本吻合。试验数据表明，采用电液比例阀控制制动缸的联合制动系统具有高响应、高精度的优点。

Simulation and Experiment Research on Electro Hydraulic Proportional Control for Heavy Vehicle Blend Brake System

A blend brake system of heavy vehicle Was proposed. The main control part of the system is an electro hydraulic proportional servo valve, through the analysis of its control property and system feature, a nonlinearable model of the brake cylinder controlled by the valve was deduced. The transfer function of the system was also obtained, and the hydraulic inherent frequency and the PID closed-loop system feature were calculated according to the selected valve feature and the systematic parameters. A PID closed-loop control system was formed. The simulated result is consistent with that tested in bench and on the site with the heavy vehicle of 50 t. The experimental data show that the proposed control method has the quality of quick response and high precision.