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.

Robust Adaptive Tracking Control for Nonlinearly Parameterized High-Order Systems With Unmatched Disturbances

“…Obviously, V k is continuously differentiable, positive definite and radically unbounded. Differentiating (20), one has…”

“…Among them, nonlinearly parameterized characteristics are also common in uncertain high-order nonlinear systems, such as diesel engine air path systems [16], air vehicle systems [17] and other physical systems [18][19]. In addition, controlled systems are often affected by external disturbances [20][21][22][23], for example, electromagnetic disturbances widely exist in the transmission process of electronic signals [21]. The existence of unknown parameters and external disturbances may lead to instability of the system and even cause great damage.…”

Constrained attitude control of flexible spacecraft with external disturbances and stochastic uncertainties on SO(3)

“…Recently, a number of studies have proposed various approaches to solve high-precision attitude control problem, including positive position feedback control approach, 5 input shaping technique, 6 disturbance observer technique, 7,8 and adaptive methodology. [9][10][11] Among them, adaptive methodology is popular because it can simultaneously deal with the unmeasurable modal vibration, rigid-flexible coupling terms, parametric uncertainties and external disturbances.…”

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.…”