Observer-Based Sliding Mode Control for Flexible Spacecraft With External Disturbance

Abstract

In this paper, attitude stabilization control for flexible spacecraft subject to external disturbance without angular velocity and flexible mode variables measurement is considered. First, an adaptive law is constructed to estimate the upper bound of a lumped disturbance consisting of flexible accessories and external disturbance. Based on the proposed adaptive law, an adaptive observer is established to estimate angular velocity and the lumped disturbance. Besides, for the case where flexible modal variables cannot be measured, a flexible modal variable observer-based sliding mode control law is proposed. Simulations are performed to verify the validity of the proposed control law. The simulation results show that the proposed control law can eliminate the influence of external disturbance for flexible spacecraft under the situation that angular velocity and flexible modal variables cannot be measured.

A Low-Complexity PD-Like Attitude Control for Spacecraft With Full-State Constraints

“…For these reasons, achieving high accuracy attitude control for spacecraft system has become a challenging problem. Over the past few years, the demanding issue of spacecraft attitude control has attracted profound attention and numerous control laws are available; for instance, backstepping method [9], eventtriggered control [10,11], model predictive control (MPC) [12,13], sliding mode control (SMC) [14][15][16][17], non-fragile output-feedback control [18,19], adaptive control [20], fuzzy control [21], fault-tolerant control [22], disturbance observer-based control [23][24][25][26][27], etc.…”