Dynamic Analysis and Adaptive Parameter Estimation for Variable Speed Control Moment Gyros with Uncertainty

This paper studied the dynamic model of Variable Speed Control Moment Gyros (VSCMG) with uncertainty. The configuration uncertainty and the rotator's inertia uncertainty are introduced into the dynamic model; the effect of uncertainties is also discussed. A new Jacobian matrix is defined to describe the effect of uncertainties. Compared with the traditional definition, this new definition includes the information of installation angle and rotator's inertia. A new steering law is designed based on singularity value decomposition theory. The linearization of dynamic model is discussed and an adaptive parameter estimation method is then proposed to deal with the parameter uncertainty. Monte Carlo approach is used for the simulation. The results show that the proposed parameter estimation method could reduce the output torque error effectively. In the same time, the estimation value can reach to its actual value quickly. It means that the proposed method could counteract the effect of uncertainties, which makes the system dynamics and output torque character dissatisfied, and the system performance is guaranteed.