Modified PID Control Using Model Driven Control for Stable Plants

In this paper, we examine PID (Proportional-Integral-Derivative) control using model driven control for stable plants. PID control systems work as one of powerful methods for controlling several plants. However, PID control remains a difficulty. That is, when P-parameter, I-parameter and D-parameter in the PID controller are adjusted using previously proposed methods, the admissible sets of P-parameter, I-parameter and D-parameter, which guarantee the stability of PID control system, are related each other. Therefore if P-parameter is changed, the admissible set of I-parameter and D-parameter which make the feedback control system stable is also changed. If the admissible sets of P-parameter, I-parameter and D-parameter are independent each other, then we can easily settle P-parameter, I-parameter and D-parameter in the PID controller to achieve desirable control specifications. However, no paper gives the admissible sets of P-parameter and I-parameter which are independent each other. The purpose of this paper is to overcome this problem and propose modified PID control systems such that the stability of control system is guaranteed and the admissible sets of P-parameter, I-parameter and D-parameter, which guarantee the stability of PID control system, are independent each other. The modified PID control system is built based on fusion of the idea of the model driven control and the parametrization of all stabilizing controllers for stable plants. A numerical example is illustrated to show the effectiveness of the proposed method.