Finite-Time Attitude Tracking Control of Rigid Spacecraft With Multiple Constraints

This article addresses the finite-time attitude tracking control problem for rigid spacecraft subject to magnitude constraints on both angular velocities and control torques. The nonlinear transformation technique and a smooth saturation model-based method are introduced to tackle the problem of multiple constraints. Through the nonlinear transformation and the input saturation model, the magnitude constraint issue is converted to a bounded problem of the transformed states and the model input. Then, a finite-time attitude control scheme is proposed for rigid spacecraft based on the backstepping approach and the robust control technique. With the derived control law, the attitude tracking errors can be driven to a small neighborhood of zero even when there exist magnitude constraints imposed on angular velocities and applied control torques. Finally, several numerical simulation examples are carried out to show the efficiency of the designed control protocol.