时变指向约束下姿态参数空间离散化路径规划方法

Parameter Space Discretization Method for Attitude Motion Planning under Time-variant Pointing Constraints

为满足深空探测器在复杂动态环境约束下的姿态机动任务需求,解决时变指向约束下姿态路径规划求解困难、路径优化性能差的问题,提出了一种基于修正罗德里格斯参数(MRP)和动态路径搜索的姿态参数空间离散化路径规划方法。通过MRP空间的笛卡尔网格划分和非奇异空间构建,实现航天器姿态的参数空间离散化和指向约束表征。考虑指向约束的时变动态特性,在三维动态空间中搜索初始到目标姿态的机动路径,并引入路径节点的时间特性,在约束冲突时对路径进行实时修正,设计非奇异空间时变约束路径搜索算法,生成执行路径节点序列。进一步,对生成的路径节点进行插值拟合,基于逆动力学方法计算角速度和控制力矩,完成姿态机动轨迹规划。仿真结果验证了该方法的有效性,可为深空探测器在时变指向约束下规划出姿态机动执行路径。

In order to meet the requirement of attitude maneuvering tasks of the deep space probe under the complex dynamic environment constraints,and solve the problems of difficult attitude path planning and poor path optimization performance under time-varying pointing constraints,an attitude parameter space discretization path planning method based on modified rodrigues parameters(MRP)and dynamic path searching is proposed.Through the Cartesian grid division and non-singular map construction of the MRP space,the discretization of the parameter space of the spacecraft attitude and the characterization of the pointing constraints are realized.Considering the dynamic characteristics of time-varying pointing constraints,the path searching algorithm is used to search the maneuvering path from the initial attitude to the target attitude in the dynamic 3D map,the time characteristics of the path nodes are introduced,and the path is corrected in real time when the constraints conflict.A nonsingular space path searching algorithm under time-variant constraints is designed,and the sequence of path nodes for execution is generated.Furthermore,interpolation path fitting is performed on the path nodes generated by the path search algorithm,the angular velocity and control torque are calculated based on the inverse dynamics method,and the attitude maneuver trajectory planning is completed.The simulation results verify the effectiveness of the method proposed in this paper.The attitude maneuvering for execution of deep space probe under the time-varying orientation constraints can be obtained.