一种PID参数闭环整定的新方法研究

A New Closed-loop Approach for PID Tuning

对于被控对象模型未知的控制系统,利用闭环阶跃响应所得数据进行PID控制器的参数调节,此方法仅需用PD控制器对被控对象进行一次闭环阶跃响应即可根据关系式得出PID控制器的比例系数、积分时间常数,以及微分时间常数.从闭环阶跃响应中获取超调量与峰值时间两个性能指标,以及控制器增益、控制器微分时间常数,经过一系列模型为二阶时滞加纯滞后的被控对象试验测试可得:所求PID控制器参数中的比例系数、积分时间以及微分时间分别与响应中的控制器增益、控制器微分时间常数、超调量,以及峰值时间成一定的函数关系.新整定方法与SIMC法(令τ_c=θ)相比,不仅使得到的系统鲁棒性更高,而且在控制系统的响应性能上也更优越.

A simple and new method is proposed for the PID controller tuning for an unidentified system by using closed-loop responses. The proposed method requires only one step test in the closed-loop system in which the process is controlled by the PD controller. A series of data is obtained from closed-loop step response,contain the overshoot, the corresponding time to reach the peak, controller＇s proportional gain and the controller＇s derivative time. Based on a range of second-order with delay test processes, two simple analytical correlations can be derived for the proportional gain, integral time and derivative time as equations set respectively. The proposed method is compared with the SIMC tuning rule, and not only gives good robustness, but also possess fine performance.