基于Popov超稳定理论的非线性电液伺服系统自适应控制研究

Adaptive Control of Electro-hydraulic Servo System with Dead-zone Nonlinearity Based on Popov Criterion

由于电液伺服系统死区非线性的存在,在正弦信号输入时,系统输出中存在高次谐波,使系统输出信号严重失真,对系统性能分析造成影响。本文基于Popov超稳定理论,设计了一种模型参考自适应控制(MRAC)系统,能消除死区对系统输出的影响,其稳定性分析显示,它能使跟踪误差迅速消失。从仿真结果上看,它能有效跟踪参考模型输出,改善系统的响应特性。

The dead zone phenomenon occurs in electro-hydraulic servo system, the output of such systems corresponding to a sinusoidal input contains higher harmonic besides the fundamental, which causes the system output distortion and has effects on system analysis. To compensate for the system, a model reference adaptive control （MRAC） design was proposed based on Popov criterion, it can cancel the dead-zone effect for improving output tracking. Stability analysis shows that the adaptive scheme can eliminate the tracking err fast. As illustrated in a simulation example, with the proposed MRAC controller, the transient response of the compensated system can be improved and accurate tracking can be achieved.