微分控制的实质及其改进路径

Essence of differential control and its improvement path

PID控制算法结构简单、稳定性好,可靠性高,有一套成熟工程整定方法。问世70余年后,仍然是使用最为广泛的回路控制算法。由于微分控制具有超前控制作用,对于容量滞后大如温度等对象,引入微分控制在提高系统的稳定性、减小超调量、提高控制精度。但是如果微分控制使用不当,会导致系统的振荡。通过对微分控制时域表达式的分析,揭示微分控制超前控制的实质,以及微分控制作用引入后对控制指标的影响,在此基础上提出了微分控制算法的改进路径。

PID control algorithm has simple structure,good stability and high reliability,and has a set of mature engineering tuning method.More than 70 years after it came out,it is still the most widely used loop control algorithm.Because of the leading control function of differential control,the introduction of differential control can improve the stability of the system,reduce the overshoot and improve the control accuracy for the object with large capacity lag such as temperature.However,if the differential control is not used properly,the system will oscillate.By analyzing the time domain expression of differential control,this paper reveals the essence of lead control of differential control,and the influence of differential control on control index.On this basis,the improvement path of differential control algorithm is proposed.