Design of a Pulse-Width-Modulation Spacecraft Attitude Control System Via Digital Redesign

摘要

This paper proposes a design method for pulse-width modulation (PWM) control systems. In the method, a discrete-time (DT) control system of the amplitude modulation type is first designed, and then it is converted into a PWM control system. Apulse width and a delay time for each PWM input are determined based on the principle of equivalent area (PEA) so that the output error between the DT and PWM control systems can be as small as possible. In this paper, the DT controller is determined bythe digital redesign of a given continuous-time (CT) controller. The digital redesign method is also based on the PEA. Thus, in spite of the inherent nonlinearity of the PWM input, linear control theories can be employed in the controller design. Theeffectiveness of the proposed method is illustrated through computer simulation using a linear model of the Japanese HOPE spacecraft.