A Design of Self-Tuning PID Control Systems Based on Pole-Assignment Method

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