Control Moment Gyro Singularity-Avoidance Steering Control Based on Singular-Surface Cost Function

Abstract

Although control moment gyros have the advantage of producing large output torques, their singularities hamper their use in spacecraft. Many studies have investigated steering laws to avoid singularities. Some of these steering laws are capable only of local avoidance. On the other hand, global steering laws require complex calculations that have to be performed offline. In this study, to establish a semiglobal singularity-avoidance method that does not require a large amount of offline calculation, a geometrical singularity-avoidance steering law is proposed by introducing a cost function. This function is termed the surface cost, and it calculates the relation between singular surfaces and the given command torque. The steering law keeps the cost function low by adding perturbation torques to the angular momentum trajectories of control moment gyros. The effectiveness of the proposed steering law is validated numerically and experimentally.