Steering Law of Control Moment Gyroscopes for Agile Attitude Maneuvers

摘要

This Note presented a steering law that not only provides the required attitude control torque but also controls the gimbals to their final target gimbal angles, eliminating the need for gimbal reorientation in agile, large-angle, and rest-to-rest multitarget maneuvers. The stability of the gimbal angle control is analyzed using a Lyapurov function, and it is shown that convergence to the final angles declines when the quadratic form becomes too small. To improve convergence, the steering law is modified by including a weighting matrix, which depends on the prescribed feedforward torque profile. On the basis of numerical simulations and considering some performance metrics, the following advances are demonstrated. First, a simply implemented steering law with desirable final gimbal angles is identified as an effective means to reduce total maneuver time and to steer the gimbals away from singularities. Second, a modified steering law effectively converges gimbals to their final angles and resolves the issue of repeatability. Consequently, a spacecraft could continuously perform agile multitarget maneuvers.