采用单框架控制力矩陀螺和动量轮的航天器姿态跟踪控制研究

Attitude Tracking Control of a Spacecraft Using Single Gimbal Control Moment Gyros and Momentum Wheels

研究利用单框架控制力矩陀螺(SGCMGs)和动量轮(MWs)组成的混合执行机构,完成航天器的姿态跟踪控制。由于现有的奇异避免操纵律无法保证SGCMGs的完全可控,而且无法精确地输出指令力矩,本文提出一种SGCMGs&MWs的混合执行机构方案。首先建立了带有混合执行机构的系统动力学模型,并基于此模型设计了姿态跟踪控制律。然后利用奇异值分解的方法将指令控制力矩进行分解,并分别分配给SGCMGs和MWs,从而当SGCMGs接近奇异时,使MWs输出沿奇异方向的指令力矩。在完成指令力矩分配后再分别设计SGCMGs和MWs的操纵律。数值仿真结果表明,利用此混合执行机构能够实现力矩的准确输出,并且SGCMGs在奇异时仍然可控,从而验证了所设计操纵律的有效性及此方案的可行性。

Attitude tracking control for a spacecraft with Single Gimbal Control Moment Gyros （SGCMGs） and Momentum Wheels（MWs） as hybrid actuators was investigated. As the usual steering laws can not ensure the full controllability of SGCMGs and can not output command torque exactly, a scheme of hybrid actuator consisting of SGCMGs and MWs was proposed. At first, the dynamic model of the system with the hybrid actuator was constructed, and an attitude tracking control law based on the model was designed. By means of singular value decomposition, the command torque is distributed to SGCMGs and MWs, enabling MWs generate the torque along the singular direction when SGCMGs are near singular states. Then, the steering laws were designed respectively for SGCMGs and MWs. The simulation results have shown that, the hybrid actuator can generate exact torque and the SGCMGs are still controllable when singular states appear. Therefore, the validity of the steering law and the feasibility of the hybrid actuator scheme are demonstrated.