Design of PWM controller for sampled-data system using digitally redesigned PAM controller

Two issues are addressed: Digital redesign of a continuous-time system with an input time delay, and translation of the pulse-amplitude modulated (PAM) controller obtained by the newly proposed digital redesign method into an equivalent pulse-width modulated (PWM) controller. A tuning parameter is introduced into the PAM controller so that the digitally controlled sampled-data states closely match the original continuous-time input time-delay states. Also, the principle of equivalent areas is applied to convert the newly developed PAM controller into an equivalent PWM controller so that the PWM controlled states closely match the PAM controlled states for a relatively longer sampling period. Two illustrative examples are provided to demonstrate the effectiveness of the proposed method.