Adaptive sliding mode based controller design for spacecraft attitude stabilization

An adaptive sliding mode controller that take the advantage of adaptive control method and sliding mode control method is designed for rigid spacecraft with external bounded disturbances. By using adaptive control law, the external disturbances can be estimated which can thus improve the robustness of the control system. System vibration is eliminated by substituting the signal function with hyperbolic tangent function. The designed controller is applied in spacecraft attitude stabilization system, and we analysis the asymptotic stability of the close loop system by employing Lyapunov stability theory. The simulation results show that this method has a good robustness to external disturbances. High precision attitude stabilization control is achieved.