Nonlinear Controller Design for Tracking Task of a Control Moment Gyroscope Actuator

Abstract

Control moment gyroscopes (CMG) are widely used as actuators for attitude control of satellites and spacecraft, which requires the controller to fulfill the tracking task of a CMG in a wide operating range, despite its highly coupled nonlinear behavior. A variety of control techniques were proposed for tracking task of the CMG unit, model 750, from Educational Control Products (ECP), but a few accomplished it in a wide operating range, e.g., the linear parameter-varying approach. Another one that may accomplish it is the nonlinear control approach. Therefore, this article proposes a nonlinear controller design based on feedback linearization for the tracking task of the CMG unit in a wide operating range. To cope with a singularity that would appear in the control signal computation, the proposed controller has a cascade structure composed of an outer tracking controller and an inner velocity controller, both based on the input-output linearization approach. The designed controller is validated via numerical simulations and real-time practical experiments.