Design of a multivariable self-tuning PID controller

PID controllers have been widely employed in real processes, and PID parameters strongly affect the control performance. Therefore, lots of schemes for tuning PID parameters have been proposed. Although fixed PID controllers are applied mainly, it is impossible to maintain good control performance for time-variant systems. In addition, most of the controlled objectives are multi-input multi-output systems in actual processes. Generally, the inputs and outputs of the systems have mutual interferences. Therefore, it is needed to calculate control parameters which decouple each interferences. In this paper, a multivariable implicit self-tuning PID control scheme is proposed. The effectiveness of the proposed method is evaluated by numerical simulation examples.