一种用于SGCMG奇异规避的CVP轨迹规划

A CVP Method for Trajectory Programming Based on Singularity Avoidance of SGCMG

采用单框架控制力矩陀螺(SGCMG)作为执行机构的小型敏捷卫星在姿态机动过程中存在着奇异问题。本文从SGCMG姿态控制系统整体出发,将奇异问题转化为状态约束的动态控制问题,基于控制变量参数化(CVP)方法,设计了一种用于SGCMG奇异规避的轨迹规划。该算法在实现小型敏捷卫星大角度姿态机动过程无奇异的基础上,将SGCMG框架角转速的最优轨迹通过CVP方法进行分段线性规划。这种规划策略对框架伺服系统的算法设计无复杂要求,仅需要简单的加减速控制,从而节约了星上资源。在轨迹规划实现过程中,考虑了工程实际中的约束条件,可以按照姿态机动任务要求规划出一条综合考虑能量资源和目标精度的最优轨迹。仿真结果表明:该算法实现了姿态参数轨迹和星体角速度轨迹的平缓变化,目标误差在1×10^(-3)量级,星体在机动过程中运行稳定,SGCMG不会出现奇异现象。

The small-scale agile satellite using single gimbal control moment gyroscope(SGCMG)as the actuator has singular state that obstructs continuous changes of the total angular momentum vector during the attitude maneuver.This paper transforms the singular problem into a dynamic control problem with state constraints in the view of overall attitude control system.The implementation of singular circumvention is based on control variable parameterization(CVP)method to obtain an optimal trajectory.This algorithm divides gimbal angular speed programming into piecewise linear in the large-angle attitude maneuver task.There is no complicated requirement for the algorithm design of the gimbal servo system.It results in benefit of resources saving that simple acceleration and deceleration control is implemented on gimbal system.In the process of trajectory planning,the constraints in engineering are taken into consideration.An optimal trajectory that comprehensively considers energy resources and target accuracy can be planned according to the requirements of the attitude maneuver task.The simulation results show that the algorithm achieves a gentle change of the attitude parameters and the satellite angular velocity trajectory.The maneuvering error is in the order of 1×10-3.The satellite runs stably and SGCMG does not have singularity during the maneuvering process.