Space robot tracking control via pulse-width modulation of thrusters

This paper examines the pulse-width modulation of thruster force for translational trajectory tracking control of a space robot. Using the maximum frequency in the desired trajectory, and knowledge of the space robot´s differential equations of motion, an estimate on the upper bound of the frequency of the trajectory tracking control law while the space robot is tracking is determined. This frequency is used as an initial guess for empirically selecting an appropriate pulse-width modulation frequency along with appropriate thruster forces levels.