组合体机动中可变形桁架运动规划研究

Study on motion planning of variable geometry truss during multibody maneuvering

目前对空间组合体中可变形桁架(Variable Geometry Truss,VGT)运动规划问题的研究集中在各级均为单自由度或离散二状态等简单结构的情形,未解决所有可调长度杆都能够自由运动的复杂结构运动规划问题。文章根据组合体的几何关系,建立了递推位姿运动学模型,再由自由漂浮系统动量守恒,建立了微分运动学模型。给出了单级VGT变化序列与运动时间分开设计的两步运动规划方法,并在优化目标中加入能量项,给出了多级冗余VGT的运动规划方法。最后通过仿真验证了算法的有效性,在算例中优化指标为J=0.879 8,该方法对以VGT作为空间操作机构的组合体研究具有一定工程指导意义。

Most of current researches about variable geometry truss（VGT）motion planning only focus on the situation that each bay has single degree of freedom.Motion planning of VGT whose each bay are variable multiple links were investigated.Kinematic model was set up based on the geometrical relationship.Considering momentum conservation of the freefloating system,velocity kinematic model was formulated.A method of designing moving sequence and moving time separately was proposed for motion planning of single bay VGT.Additionally,multi-bay VGT motion planning problem was solved by energy optimum.Simulation results show that the algorithm is effective,and the optimizing index is 0.879 8.The method has practical benefits to the space operation system with VGT.