Design and implementation of a self-tuning PID controller

PID control schemes based on the classical control theory, have been widely applied to real control systems, and there have been a lot of works on the tuning of PID parameters, as they affect control performance. Several self-tuning and auto-tuning PID techniques have been reported for systems with unknown or slowly time-varing parameters. None, however, is applicable to discrete-time system with unknown dead time. In this paper. a self-tuning PID control algorithm is proposed based on the relationship between the PID control law and the generalized minimum variance control law which is one of self-tuning control strategies. The proposed control scheme is practically evaluated on a temperature control system of a polybutene reactor. Copyright (C) 1998 IFAC.