A practical design of multiloop robust PID control systems

In this paper, a new design scheme of multiloop predictive self-tuning PID controllers is proposed for multivariable systems. The proposed scheme first uses a static precompensator as an approximately decoupling device in order to roughly reduce the interaction terms of the controlled object. The static matrix precompensator is adjusted by an on-line estimator. Furthermore, by regarding the approximately decoupled system as a series of single-input single-output subsystems, a single-input single-output PID controller is designed for each subsystem. The PID parameters are calculated on-line based on the relationship between the PID control and the generalized predictive control laws. The proposed scheme is numerically evaluated on a simulation example. (C) 2004 Wiley Periodicals, Inc.