Abstract
In this paper, we propose a PID control design method for decentralized control systems from the inverse linear quadratic problem viewpoint by using the structure of controllers obtained by the ILQ(Inverse Linear Quadratic) design method. First, we show an optimal decentralized PID design method for systems with relative degree no more than 2 and block diagonal decoupling matrix. Then, we derive a necessary and sufficient condition for the stability of the closed loop system using our proposed design method of decentralized PID control in the case where the decoupling matrix is not block diagonal. Moreover, we show that a desired transient response with decoupled input/output characteristics can be achieved by our decentralized PID controller. Finally, we illustrate the effectiveness of our proposed method by simulation.
