基于多体动力学特性的机械手时间最优轨迹规划

Trajectory Optimization of Manipulator for Minimum Working Time Based on Multi-body Dynamic Characters

基于系统动力学模型,针对2点间获取具有最优工作时间负载轨迹问题进行了系统研究。考虑到机械手本身构型特点及动力学模型的完备性与通用性,以多体动力学理论为指导,建立在罗德里格公式定义的系统构件旋转矩阵和Chales定理基础上,采用拉格朗日原理构建系统动力学模型。进而采用线性迭代法(Iterative linear programming,ILP)与系统动力学方程修正相结合的方法,并以一维时间搜索法获取系统最优工作周期。最后针对一3自由度空间机械手进行工作周期优化仿真,并对仿真结果进行分析。

A computational technique is developed for obtaining the time-optimal trajectory of a manipulator to carry a specified pay load for a given two-end-point task based on the system dynamic model. Considering the inherent configurations of manipulators as well as the generality and integration of dynamic modeling, the transformation matrices of system components are defined by Rodrgiuez formula according to Chales theory based on the multi-body dynamics. Then, the system dynamic model is derived via Lagrangian approach. The method combining the iterative linear programming （ILT） with the dynamic correcting is developed to determine the system minimum working time of manipulators by one dimensional searching approach along the time axis. At last, one numerical example involving a 3-DOF spatial manipulator using the approach is presented and the results are discussed.