A Design of Self-Tuning PID Controller with a Time-Delay Compensator

Abstract PID control schemes have been widely used for various process control systems for a long time. However, since such processes have relatively large dead times and uncertainties caused by modeling errors and system fluctuation, it is non-trivial to determine suitable PID parameters. In this paper, a design scheme of self-tuning PID controllers is proposed for unknown processes with dead times. This scheme is equipped with a parallel feedforward compensator to compensate for the dead times. The PID control system is then designed for the augmented system. The PID control parameters are determined adaptively based on on-line process identification and the relationship between the minimum variance control law and PID control law.