电液伺服试验机的QFT控制研究

由于电液伺服试验机系统内存在较强的时变特性和非线性,并且试件等负载特性经常变化,导致系统存在很大的参数不确定性.当被控系统的参数等特性发生变化时,采用固定参数的传统PID控制难以获得满意的控制效果,如果重新调整参数又极大地增加了控制操作的复杂性.为解决此问题,采用定量反馈理论(QFT)的控制器设计方案,对电液伺服试验机...

Research on QFT Control for Electro hydraulic Servo System

The electro-hydraulic servo system has strong non-linearity, and, there is a large parameter uncertainty due to the change of the specimen and external working conditions. It is often difficult to obtain satisfactory control effect by using traditional PID control. When the system parameters change, the performance of the PID control will decline. If the parameters are adjusted again, the complexity of the control operation will be greatly increased. In addition, the high frequency amplitude-frequency characteristic of electro-hydraulic servo position system decreases, and it is difficult for PID control to adjust the high frequency part of the system. In this paper, quantitative feedback theory (QFT) is used to control the electro-hydraulic servo system. QFT is suitable for controlling uncertain systems, and can "tailor" the system performance in different frequency bands. It can widen the system bandwidth and improve the high frequency performance of the system. The simulation results of electro-hydraulic servo position system show that QFT controller has higher control precision and stronger robustness than PID control.