基于速度椭球的3SPS-1PS并联髋关节试验机尺度综合分析

Dimension Synthesis for a 3SPS—1PS Parallel Hip Joint Simulator Base on Velocity Ellipsoid

对一种用于评价人工髋关节材料的3SPS—1PS并联髋关节试验机的结构参数进行了尺度综合分析。将速度椭球概念应用到试验机尺度综合中,利用速度椭球特性,即在给定任务条件下,速度椭球的长轴长度越短,驱动器的驱动速度越低。速度椭球长轴长度等价于其雅克比矩阵最大奇异值,因此为了获得最小驱动速度,以雅克比矩阵的最大奇异值的最小值为尺度综合目标,对3SPS—1PS并联髋关节试验机进行了尺度综合,并利用尺度综合得到的参数对工作空间进行了仿真分析。结果表明,尺度综合后的试验机可达工作空间包含任务空间,满足实验要求。

Dimension synthesis for a parallel hip joint simulator with 3SPS—1PS manipulator is carried out. On the basis of velocity ellipsoid,the parallel hip joint simulator is optimized for getting a lower driving velocity. According to the velocity ellipsoid equations,the long axis of the velocity ellipsoid is equivalent to its maximum singular value of Jacobi matrix. In order to get the lower driving velocity,the maximum singular value is selected as the aim of the dimension synthesis to optimize the parameters of the parallel hip joint simulator,and the working space of the parallel hip joint simulator is carried out according to the optimized parameters. The simulation results show that the actual working space contains the task working space,so the optimized parameters satisfy the test requirement.