Minimum-Power Robotic Maneuvering Using Control-Moment Gyroscopes

Abstract

Control-moment gyroscopes (CMGs) are power-e‐cient actuators that typically provide high torques to large spacecraft. In this study, we propose the use of CMGs in actuating a space robotic arm, whose tasks include manipulating a payload. This paper derives the full nonlinear equations of motion for a three degree-of-freedom system with a mass-center ofiset and incorporates a closed-loop control design. Under a controlled motion, we demonstrate that a CMG-driven robotic arm can manipulate a payload with minimal changes to the system energy. By investigating how a payload afiects the dynamics for single-body and multi-body systems, we flnd that the equations of motion and expressions for power are simpler when the individual bodies are moved sequentially. However, by comparing both sequential and simultaneous body motions for randomly chosen maneuvers, we show that less energy is expended on average when the bodies are controlled simultaneously.