NEW DESIGN METHODS OF ACTUATOR SATURATION COMPENSATORS FOR PROPORTIONAL, INTEGRAL AND DERIVATIVE CONTROLLERS

This paper proposes five new schemes of saturation compensator designs for PID (proportional, integral and derivative) controllers. Unlike p revious works, these are derived using frequency domain techniques. Ba sed on stability analysis of the compensated systems, comparisons of s tabilities of the compensation schemes relative to each other are esta blished, with the result that their relative orders depend only on the PI/PID parameters. A new class of variable-structure compensators is also proposed. These variable-structure compensators combine the advan tages of their individual constituents to achieve better results. Desi gn procedures, for both fixed-and variable-structure compensators, are then presented as the main theme of this paper. Results for the relat ive stabilities and design procedures are illustrated with examples, s howing the validity and superiority of the proposed methods.