Robust Adaptive Variable Structure Control of a Flexible Spacecraft Containing Input Nonlinearity/Dead-Zone

摘要

In this paper, an approach to the vibration suppression of a three-axis stabilized flexible spacecraft is investigated during attitude maneuvering in the presence of bounded model uncertainty, external disturbances and control input nonlinearity/dead-zone. The approach of the current study is the construction of an adaptive variable structure output feedback controller to stabilize uncertain dynamics systems with explicitly considering nonlinearity/dead-zone in the control input. It is shown that the controller guarantees the global reaching condition of the sliding mode in uncertain systems. The significant advantages of this control include the following: (ⅰ) the presented adaptive variable structure output feedback controller can derive the trajectories of an uncertain system with input nonlinearity/dead-zone onto the sliding mode, and (ⅱ) the variable structure output feedback control can also be achieved through adaptive control without knowing the boundaries of the uncertainty and perturbation terms in advance.