敏捷卫星姿态机动的非线性模型预测控制

Nonlinear model predictive control of agile satellite attitude maneuver

针对以金字塔构型控制力矩陀螺(CMG)为执行机构的敏捷小卫星开展了先进机动控制算法的研究。在考虑控制力矩陀螺力矩约束及增量约束情况下,设计了基于非线性模型预测控制(NMPC)方法的卫星姿态快速机动控制律及操纵律。通过多种仿真分析了控制器设计参数变化对卫星姿态机动的影响,并与终端滑模控制方法进行了比较。实验结果表明,增大跟踪性能加权矩阵或延长预测时域均可以提高卫星姿态机动速度,缩短卫星姿态机动时间。设计的控制方法能够使卫星姿态在18s内实现40°的大角度快速机动,姿态指向精度和稳定度分别为0.01°和0.04(°)/s,与终端滑模控制方法相比,机动速度及稳态性均得到提高。本文方法为敏捷小卫星的在轨应用方式提供了理论支撑。

By taking apyramid configuration Control Moment Gyro（CMG）as the actuator,an advanced maneuver control algorithm was explored.In consideration of the constraint or incremental constraint of control torque for the CMG,the control law and manipulation law for the satellite attitude fast maneuver were designed based on the Nonlinear Model Predictive Control（NMPC）method,and the impact of satellite attitude maneuver controller parameters on tracking performance was analyzed by different simulations.The simulation results indicate that increasing tracking performance weighting matrix and lengthening predicting time domain,the satellite attitude maneuver speed can be improved and the maneuver time can be shortened.The designed control method can achieve 40°attitude maneuver in the 18 s,and the corresponding pointing accuracy and stability are 0.01°and 0.04（°）/s,respectively.Simulation results were also compared with that the terminal sliding-mode control method,and it shows that the control performance of satellite attitude maneuver has been improved.The proposed control method in this paper provides a theoretical support for the in-orbit applications of agile small satellites.