针对航天器快速姿态机动控制问题,考虑存在参数不确定性、外部干扰、推力器安装偏差以及控制输入饱和受限的多约束条件下,提出了一类自适应终端滑模有限时间控制方法,显式地引入推力器输出的饱和幅值,确保闭环系统在有限时间内快速收敛到滑模面的邻域内;同时,通过引入参数自适应学习律,使得控制器的设计不依赖于参数不确定性、外部干扰以及推力器安装偏差信息;此外,基于Lyapunov稳定性定理对所提出的控制器进行了理论分析.并通过给定某型航天器参数进行了数值仿真,结果表明在考虑多约束情况下,系统具有较快的收敛速度,且具有很好的动态性能,从而验证了所设计方案的有效性、可行性.
An adaptive terminal sliding-mode-based finite-time control scheme is proposed for the attitude maneuver control of a spacecraft, in which the parameters uncertainty, external disturbances, thruster misalignment and input saturation are taken into account simultaneously. By considering the saturation magnitude of the thruster output, this scheme ensures the closed-loop for a rapid convergence into the neighborhood of the sliding surface in a finite period of time. The self-adaptive law for the parameters makes the control design independent of the parameter uncertainty, the external disturbances and the thruster misalignment. The controller is analyzed by using Lyapunov stability theorem. Numerical simulation is performed on an aircraft model with given parameters. Experimental results show a rapid-convergence and desired performances when multiple constraints are considered, thus, validating the effectiveness and feasibility of the designed scheme.