基于会切场推力器无拖曳系统建模及参数优化

随着卫星重力测量技术的突破性进展，对航天器试验环境要求也在不断提高，航天器受到的残余扰动必须尽可能减小。作为中国将来重力场测量卫星备选主推力器的会切场推力器，其推力器的控制精度直接决定了测量的准确性。文章首先通过PID方法设计了位移模式下的无拖曳控制器，该控制器在预估阻力系数、参考质量与卫星本体的位移差、速度差等性能方面有良好的表现，在应对卫星运行时的突发情况时表现出很强的稳定性。但PID参数没有达到最优解，在此基础上对于该模型的控制精度进行优化，用遗传算法对PID控制的参数进行筛选。结果分析表明，会切场推力器的控制精度有所改善，NTW方向上的速度和位移误差均减小；推力阻力和显著减少；控制精度提高，更好地满足使用需求。

Drag free system modeling and parameters optimization based on cusped field thruster

With the breakthrough progress of the satellite gravity measurement technology, the demand for the spacecraft's experimental environment increases, and the residual disturbance of the spacecraft must be reduced as far as possible.As the cusped field thruster of China's future alternative gravity thrusters for measuring satellites, the control accuracy of thrusters directly determines the measurement accuracy. A drag free controller with state mode was designed by the PID method. The controller performs well in predicting the performance of the drag coefficient, the reference mass, the displacement difference and the speed difference of the satellite body. When dealing with satellite operation sudden situation it showed strong stability. However, the PID parameters didn′t reach the optimal solution. Based on this, the control accuracy of the model was optimized. The genetic algorithm was used to filter the PID control parameters. The results show that the control accuracy of the cut off thruster has improved, the speed and displacement errors in the NTW direction are reduced, the thrust resistance is significantly reduced, the control accuracy is improved, and the requirement is better satisfied.