含死区和饱和的非线性系统PID控制器设计

Design of PID Controller for Nonlinear System with Dead-zone and Saturation

基于死区饱和的描述函数模型以及线性系统PID控制器参数稳定域确定的方法,提出一种含有死区饱和的非线性系统PID控制器设计方法。针对非线性环节的不同正弦输入幅值,给出一种新的等效逆Nyquist曲线。可从不同的正弦输入幅值时PID参数稳定域的交集中选取PID控制器参数。该控制器可以有效地减轻非线性的影响。对于开环不稳定的对象,加入一个参考输入预过滤器。所建议的方法,可以使含死区饱和环节的闭环系统稳定。仿真实例表明,该方法有效。

Based on the describing function model of dead-zone and saturation and the method of determi- ning the stabilizing region of PID controller for linear system, an approach is presented for the design of PID controller for a given nonlinear system with dead-zone and saturation. The new equivalent inverse Nyquist plots are given for the different sinusoidal input amplitudes of nonlinear component, and the pa- rameters of PID controller are selected from the intersection sets of stabilizing controller parameter region for different sinusoidal input amplitudes. The controller can effectively mitigate the nonlinear effect. For unstable open-loop system, a prefilter is added on the reference input. The proposed approach can be used to stabilize the closed-loop system with nonlinearity. The simulation examples demonstrate the valid- ity of the proposed approach.