基于新型终端滑模的航天器执行器故障容错姿态控制简

 针对受干扰的刚体航天器冗余执行器存在故障与控制受限的姿态跟踪控制问题，提出一类基于新型指数形式的非奇异快速滑模面（ENFTSM）与趋近律的姿态容错控制器设计方法。当部分推力器发生故障时，假设剩余推力器具有输出饱和特性且能提供足够推力保证航天器执行任务，相比一般终端滑模控制器，本文设计的控制器不仅能使系统状态以更快的速度到达平衡点，且不需要在线对执行器故障信息进行检测和分离。基于Lyapunov方法证明本文设计的控制器能保证闭环系统稳定，且能有效地抑制外部干扰、控制受限和执行器故障等约束。最后对提出的控制算法进行了数值仿真，其结果表明了该控制器的有效性。

Novel Terminal Sliding Mode Based Fault Tolerant Attitude Control for Spacecraft Under Actuator Faults

An exponent nonsingular fast terminal sliding mode (ENFTSM) control law is investigated in this paper for a rigid spacecraft with redundant thrusters in which thruster faults, and control input saturation as well as external disturbances have to be explicitly considered simultaneously. More specifically, in this proposed control scheme, fast convergence of spacecraft attitude tracking is achieved and faster reaching time can be guaranteed in comparison with the terminal sliding mode. When thruster fault occurs, the control parameters are adjusted dynamically in such a fashion that no fault detection and isolation mechanism is required in advance, and only the remaining active thrusters are assumed to be able to produce a combined force sufficient to allow the spacecraft to perform the given operations within the saturation magnitude. Lyapunov stability analysis shows that the resulting closed-loop system is stable it can withstand the effect of external disturbances, control input saturation and even faults by appropriately choosing the design parameters. The attitude tracking performance using the controller is evaluated through a numerical example.