四阶球面并联机械手指向轨迹最优动态规划

Optimal Dynamic Planning of Finger Direction Trajectory for Fourth-order Spherical Parallel Manipulator

球面并联机械手可以有效地用于定位任务的执行,利用姿态优化可提高平行腕关节的动态特性,所使用的指标是基于简化到移动平台的机械手惯性矩阵,可很容易地算出腕部总动能。首先,针对每个指向方向寻找导致最佳动态操纵能力的姿态来解决冗余。然后,通过Bezier曲线在球体表面上规划一个路径;优化问题的性能函数通过球面姿态驱动平台,该球面姿态沿一个有用的方向赋予最大角加速度,实现并联机械手快速定位最优任务规划。通过在多体软件环境中进行的逆动力学分析,在机械手控制过程中,相对于选取的对比算法具有更佳的上升时间、超调量以及调节时间,体现了所提算法的控制有效性。

The spherical parallel manipulator can be effectively used in the execution of positioning tasks.The dynamic characteristics of the parallel wrist joint can be improved by using attitude optimization.The index used in this paper is based on the inertia matrix of the manipulator simplified to the mobile platform,and the total kinetic energy of the wrist can be easily calculated.Firstly,the redundancy is solved by searching for the posture that leads to the optimal dynamic control capability for each direction.Then,a path is planned on the surface of the sphere through the curve;the performance function of the optimization problem is driven by the spherical attitude platform,which gives the maximum angular acceleration along a useful direction,and achieves the optimal task planning for rapid positioning of parallel manipulators.Through the inverse dynamics analysis in multi-body software environment,the control process of the manipulator in this paper has better rise time,overshoot and adjustment time than the selected control algorithms,which reflects the control effectiveness of the proposed algorithm.