基于相角裕度优化的PID参数整定方法研究

Study on Tuning Methods of PID Controllers Based on Phase Margin Optimization

针对复杂工业过程的大滞后、参数不确定等特性,提出一种新的鲁棒PID控制器参数整定方法。该方法通过使系统开环传递函数的相角裕度最大化,来求取各个PID参数。由于该方法的稳定裕量是通过取明确依赖于频率的模型来获得,从而避免了陷入保守性。仿真结果表明,使用本文提出的控制器整定方法,在命令输入发生阶跃变化时,控制系统都有很好的动态响应,同时在系统参数发生变化或存在未建模动态时,也能保证系统的稳定鲁棒性。

Aiming at kinds of long-time delay and uncertainties of system parameters in complex industry process, a novel method for tuning PID parameters was proposed. The tuning problem was solved by maximizing the phase margin of the Nyquist curve of the open loop transfer function. The stability margin can be obtained through the model which depend on frequency without falling into conservatism. Simulation results show that good response of the control system is due to the step change of command and the system has good robustness when system parameter changes or modeling is uncertain.