Generalised minimum-variance stochastic self-tuning controller with pole restriction

An algorithm to incorporate pole restriction into the generalised minimum-variance stochastic self-tuning controller is proposed. The closed-loop poles of the system are restricted to a user-chosen circle in the z-plane to meet maximum percentage overshoot and settling time specifications. A deadband introduced to the basic pole restriction algorithm leads to a piecewise time-invariant controller. The deadband algorithm reduces computational requirements and enhances the stability robustness of the system. Finally, simulation results indicate that in the control of a plant that changes bandwidth significantly during operation, the pole restriction controller is superior to its pole placement counterpart.