小型控制力矩陀螺扰动建模及性能指标分析

为实现遥感卫星的高精度指向能力，对遥感卫星星上常用执行机构控制力矩陀螺扰动及性能指标评定进行了研究。首先，充分考虑小型控制力矩陀螺的静动不平衡量以及框架轴的安装误差，根据动量定理和动量矩定理建立了完整的星载小型控制力矩陀螺的动力学模型，并对所建立模型的正确性进行了理论分析和仿真验证；其次，将含有扰动特性的小型控制力矩陀螺应用到星上，建立了整星动力学模型，并选用合适的框架伺服控制系统和转子伺服控制系统，完成整星的姿态稳定控制任务；最后，采用数值仿真的方式分析了陀螺转子静动不平衡因素以及框架角测量误差对星体姿态精度和稳定度带来的影响。结合任务要求，对小型控制力矩陀螺设计提出静动不平衡量等指标要求，以期使其满足星上光学有效载荷的成像要求。

Disturbance Modeling and Performance Index Evaluation of the Small Control Moment Gyroscope

Control moment gyro (CMG) is widely used as the actuator for attitude control on satellites recently. To realize high precise pointing capability of a high resolution remote sensing satellite, the disturbance modeling and performance index evaluation of CMG were discussed. Firstly, considering the static and dynamic imbalances of the rotor and installation errors, the small CMG dynamic model was constructed by means of the theorem of momentum and theorem of angular momentum. The validity of this model was analyzed based on an experience model of a flywheel and testified by numerical simulation. Secondly, a cluster of the CMGs were adopted and the whole satellite dynamic model was derived. To complete the mission of the satellite attitude stabilization control, the reasonable servo control systems of the gimbals and the rotor were selected. Finally, the influences of the CMG disturbances on the attitude precision and satellite stability were analyzed in detail. According to the space mission of the high resolution remote sensing satellite, the constraint condition of the CMG performance index was obtained to meet the imaging requirements of the optical payloads.