SGCMG框架伺服系统动力学建模与低速控制

Dynamics Modeling and Low Rate Control of Gimbal Servo System for Single Gimbal Control Moment Gyro

单框架控制力矩陀螺(SGCMG)框架伺服系统内部存在的各种干扰会严重影响陀螺的力矩输出精度。为了实现力矩输出的高精度控制,需要对框架伺服系统进行精确动力学建模与控制。通过对作用于航天器上SGCMG的详细动力学分析,建立了框架伺服系统动力学模型,其中考虑了动静不平衡干扰力矩以及摩擦力矩。基于正弦永磁同步电机,利用自抗扰理论设计了框架伺服系统内外环控制器。仿真结果表明,在忽略转子不平衡所引起的高频干扰力矩的前提下,此控制器能对内外环存在的所有建模及未建模干扰进行准确估计和补偿,保证了框架的高精度控制。通过仿真还得到了转子不平衡对框架控制精度的影响量级,将为进一步研究如何抑制不平衡振动提供参考依据。

In order to ensure the high precision of output torque, the precise dynamics modeling and control of gimbal servo system were studied. By thorough dynamics analysis of single gimbal control moment gyro （SGCMG） mounted on the spacecraft, the dynamic model of gimbal servo system was established, taking into account the largest disturbing torque along the gimbal axis resulted from rotor imbalance and the friction torque. For the gimbal servo system using a sinusoidal permanent magnetic synchronous motor （PMSM）, the inner and outer loop controllers were both designed based on the active disturbance rejection control （ADRC） theory. The simulation results demonstrate that under the assumption that the high-frequency disturbing torque resulted from rotor imbalance is ignored, the modeled and unmodeled disturbance existing in both loops were estimated and compensated exactly using the ADRC controller, so that the high precision control of gimbal servo system was ensured. The results also show the effect level of the rotor imbalance on gimbal control precision.