A control scheme for the reduction of thruster-manipulator interactions in space robotic systems

Abstract

Space manipulators mounted on an on-off thruster-controlled base are envisioned to assist in the assembly and maintenance of space structures. When handling large payloads, manipulator joint and link flexibility become important, for they can result in payload-attitude controller fuel-replenishing dynamic interactions. In this paper, the dynamics model of an N-flexible-joint space manipulator is developed. The model of a three-flexible-joint manipulator mounted on a six-degree-of-freedom spacecraft is used to compare three different on-off thruster attitude control systems. Two variations of a classical control scheme are suggested to minimize such undesirable dynamic interactions, as well as thruster fuel consumption.