反作用飞轮非理想电磁力矩对卫星姿态的影响

Effect of non-ideal electromagnetic torque in reaction wheel on satellite attitude

摘要:

针对反作用飞轮中存在的力矩波动和力矩跳动这2种非理想电磁力矩,分析其产生机理,建立了轮控微小卫星姿态稳定控制系统的仿真模型.分析了力矩波动系数和力矩波动频率、力矩跳动幅值和跳动持续时间对卫星姿态的影响,最后给出抑制非理想电磁力矩的措施.分析和仿真表明:当卫星姿态控制精度要求较高时,非理想电磁力矩的影响不容忽视.力矩波动使卫星姿态发生同频率波动,在飞轮转速过零时力矩波动的影响最大,力矩跳动使卫星姿态发生偏差.避免反作用飞轮转速过零、提高力矩波动频率、降低力矩波动系数、减小力矩跳动幅值和跳动持续时间均可有效降低非理想电磁力矩对卫星姿态的影响.

Abstract:

The torque ripple and the torque jumping exist in the electromagnetic torque of reaction wheel.The mechanisms of these two kinds of non-ideal electromagnetic torque are analyzed.The simulation model of micro-satellite attitude control system controlled by reaction wheel is constructed.Then the effect of the torque ripple coefficient,the torque ripple frequency,the torque jumping amplitude,and the duration of jumping torque on micro-satellite attitude are analyzed.Finally the methods to eliminate the non-ideal electromagnetic torque are proposed.The results show that the effect of non-ideal electromagnetic torque cannot be neglected in case that the required controlling precision of satellite attitude is higher.The ripple torque and the jumping torque make satellite attitude generate identical frequency ripple and bias error,respectively,and the effect of these two kinds of torque on micro-satellite attitude is maximum under zero-crossing rotate speed of reaction wheel.The methods,such as preventing zero-crossing rotate speed of reaction wheel,improving the torque ripple frequency,lowering the torque ripple coefficient,and decreasing the torque jumping amplitude and duration,can reduce the effect of non-ideal electromagnetic torque on satellite attitude effectively.