Flexible spacecraft attitude robust tracking control based on fractional order sliding mode

A new robust fractional order sliding mode controller is proposed for flexible spacecraft attitude tracking control. The fractional differential operator is used both in the sliding surface and control input because of its rapid convergence and information memory, and the new controller has the dual advantage of a fractional differential operator and a sliding mode control, so that the flexible spacecraft attitude tracking control system has rapid convergence and strong robustness to external load disturbances and parameter variations. Furthermore, the stability of the whole system is proved by Lyapunov theory and fractional stability theory, and the convergence advantages of a fractional order sliding surface are analyzed. Numerical simulations are also included to reinforce the analytic results and to validate the excellent effect of the new robust fractional order sliding mode controller.