基于优化非线性控制的液压制动系统压力跟踪仿真研究

Pressure Tracking Simulation of Hydraulic Braking System Based on Optimized Nonlinear Control

为提高车辆制动过程中控制系统的响应速度,设计车辆液压制动非线性PID控制优化系统,并对制动压力跟踪效果进行仿真。给出车辆液压制动系统平面图,分析车辆行驶和制动过程中液压系统的工作原理。采用数学模型对车辆液压制动系统进行简化,针对输入的不确定性设计了非线性PID控制系统。采用遗传算法对非线性PID控制系统进行优化,给出了液压制动非线性PID控制系统的优化流程。在不同初始状态和不同压力信号条件下,采用MATLAB软件对制动压力跟踪误差进行仿真,并与优化前的仿真结果进行对比和分析。结果表明:在非线性PID控制系统中,液压制动压力跟踪误差较大,控制参数调整速度较慢;在遗传算法优化后的非线性PID控制系统中,液压制动压力跟踪误差较小,控制参数调整速度较快。采用遗传算法优化非线性PID控制系统,可以提高整个系统的反应速度,获得良好的制动效果。

In order to improve the response speed of the control system in the process of vehicle braking, the nonlinear PID control optimization system of vehicle hydraulic braking was designed, and the effect of braking pressure tracking was simulated.The plane graph of the vehicle hydraulic braking system was given, and the working principles of the hydraulic system in the process of vehicle driving and braking were analyzed.The mathematical model was used to simplify the hydraulic brake system of the vehicle, and the nonlinear PID control system was designed for the input uncertainty.The genetic algorithm was used to optimize the nonlinear PID control system, and the optimization process of the nonlinear PID control system of the hydraulic brake was given.Under the conditions of different initial state and different pressure signal, MATLAB software was used to simulate the tracking error of the brake pressure, and the simulation results were compared and analyzed with those before optimization.The simulation results show that in the nonlinear PID control system, the tracking error of the hydraulic brake pressure is large, and the adjustment speed of control parameters is slow;in the nonlinear PID control system optimized by genetic algorithm, the tracking error of hydraulic brake pressure is small, and the adjustment speed of control parameters is fast.By using the genetic algorithm to optimize the nonlinear PID control system, the response speed of the whole system can be improved and good braking effect can be obtained.