Boundary adaptive iterative learning control for flexible satellite system with input constraint

This paper is concerned with the constrained vibration control problem of a flexible satellite system in the presence of unknown external disturbances. Therein, the dynamic model of satellite system is governed as a high order partial differential equation. Unknown disturbances directly result that existing approaches fail in solving the precise control problem for the considered system. To this end, this paper proposes a boundary adaptive iterative learning controller. During the design of the control law, in response to the input constraint which is described by a saturation function model, a hyperbolic tangent function is employed. Novel adaptive learning laws are proposed to learn the upper bounds of disturbances exerted at the solar panels and the centerbody. The closed-loop stability is theoretically proved through a Lyapunov–Krasovskii composite energy function. Numerical simulations are provided to represent the effectiveness of the proposed control method.