基于组合控制的电液执行机构气门阀运动误差控制仿真研究

Simulation Research on Valve Motion Error Control of Electro-hydraulic Actuator Based on Composite Control

当前,发动机气门阀回程着落时不稳定,导致其跳动幅度较大。针对此问题,设计电液执行机构控制系统,并对气门阀运动位移和速度进行仿真验证。建立电液气门阀驱动平面简图,分析液压执行机构驱动方式。给出3种不同状态下伺服阀阀芯位置变化过程,从而得到气门阀液压驱动变化表达式。分析神经网络PID控制系统和跟踪微分器过滤原理,设计组合控制系统。为了验证不同干扰条件下气门阀运动位移和速度产生的误差,通过MATLAB软件对其进行仿真验证。仿真结果表明:在受到相同外界干扰条件下,采取传统PID控制系统,气门阀运动位移和速度的最大误差偏大,误差跳动幅度偏大;采用组合控制系统,气门阀运动位移和速度的最大误差偏小,误差跳动幅度偏小。采取组合控制系统,系统能够抑制外界的干扰,气门阀回程着陆时相对稳定,从而降低气门阀位移和速度的输出误差。

At present,the return landing of the engine valve is not stable,which results in a large jump range.Therefore,the control system of the electro-hydraulic actuator was designed,and the movement displacement and speed of the valve were simulated.The driving plan of the electro-hydraulic valve was established,and the driving mode of the hydraulic actuator was analyzed.The change process of the position of the servo valve core in three different states was given,and the expression of the change of the valve hydraulic drive was obtained.The neural network PID control system and the filter principle of tracking differentiator were analyzed,and the combined control system was designed.In order to verify the error of valve movement displacement and speed under different interference conditions,it was simulated and verified by using MATLAB software.The simulation results show that under the condition of the same external interference,the maximum errors of the valve movement displacement and speed are larger and the error jump amplitudes are larger when the traditional PID control system is adopted;the maximum errors of the valve movement displacement and speed are smaller and the error jump amplitudes are smaller when the combined control system is adopted.Combined control system can suppress the external interference,and the valve return landing is relatively stable,thus the output errors of the valve displacement and speed are reduced.