双通道继电特性及其应用——SISO情形

A Two-channel Relay and Its Application--The SISO Case

研究了 SISO系统中引入双通道继电特性后的单位反馈闭环系统 .基于描述函数法和 Nyquist稳定判据给出了该系统极限环振荡的存在条件和稳定条件 .建立了极限环振荡信息与前向通道频率特性的关系 .在此基础上提出了双通道继电反馈方法的两种应用 ,即提取过程多象限多点频率特性和控制系统操作性能的闭环监测 .仿真取得了非常好的结果 。

The two channel relay feedback of SISO systems is analyzed in depth. With the use of the describing function method and Nyquist stability criterion, the existence and stability conditions for corresponding limit cycle oscillation are presented. Furthermore, the relation between the information of the limit cycle and the frequency characteristic of the forward path is built. On the basis of these conclusions, two ways to apply two channel relay feedback--extracting multi point frequency characteristics in multiple quadrant and closed loop performance monitoring--are given. Simulations show satisfying results and verify the method presented in this paper.