直线驱动型并联机器人工作空间分析与优化

摘要

Aiming to solve the complicated problem of linear driving parallel robot workspace with less study,according to the structure and kinematics model of linear driving parallel robot with the limits of the Hooke joint and the singularity to the workspace,the numerical search method was used to solve the workspace of the parallel robot with the tendency of size,shape,and symmetry of the workspace with respect to the different sets of architectural parameters chosen for the manipulator.A new approach was presented to the architecture optimization of the linear driving parallel robot based on the performance of a weighted sum of global dexterity index and a new performance index-space utility ratio (SUR),and the mathematic model of parameters optimization was set up based on the objective function of this ratio.Particle swarm optimization was used to optimize the parameters of the linear driving parallel robot,the optimal parameters were obtained based on the performance of the space utility index with the global dexterity index in different environments.This method was helpful in designing the linear driving parallel robot and other types of parallel robot.In the end,the laser tracker was used to measure the actual workspace to compare with the theoretical model,which verified the theoretical model of the workspace,laid the foundation for the subsequent optimization of the linear driving parallel robot.%与旋转驱动型相比,直线驱动并联机器人具有更大的工作空间,但存在工作空间求解较复杂、精度不高和优化目标不合理的问题.针对上述问题,根据并联机器人的结构和运动学模型,提出了一种极坐标变步长迭代搜索法求解并联机器人工作空间,分析各结构参数变化对工作空间的形状、尺寸、对称性的影响趋势.提出一种综合机器人灵巧度与工作空间利用率的全局混合性能指标,并以此为目标函数建立了结构参数优化的数学模型,利用粒子群算法对不同工况下机器人尺寸参数进行优化,得到基于机器人操作性能和工作空间利用率的最优参数,对不同权重下优化得到的参数进行仿真,验证了目标函数的正确性和有效性.通过激光跟踪仪测出的实际工作空间与理论工作空间模型进行对比,验证了工作空间理论模型的正确性,为后续的尺度综合研究打下基础.