L2-gain based adaptive sliding mode coordinated attitude control of satellite formation with time-varying delays

With the consideration of communication time-varying delays and input time-varying delays, as well as parametric uncertainties and external disturbance, an adaptive sliding mode L2-gain attitude coordinated controller is proposed for satellite formation under a general undirected interaction topology. Firstly, an adaptive sliding mode controller is developed, in which the adaptive technique is employed to estimate the upper bound of the perturbation suffered from parametric uncertainties of the inertia matrix. A Lyapunov-Krasovskii function with information of time-delays is constructed to prove the asymptotic stability of the closed-loop system theoretically. Then, the controller is improved to ensure high robustness in the sense of L2-gain to the total perturbation from both error of parameter estimation and external disturbance, in which time-varying delays are also included explicitly. Numerical simulations demonstrate the effectiveness of the proposed attitude coordinated controller.