新型球面并联机构运动学分析及尺度综合  

Kinematics Analysis and Scale Synthesis of a Novel Spherical Parallel Mechanism

作　　者：常振 王成博[1] 王高峰[1] 高建设[1] Chang Zhen;Wang Chengbo;Wang Gaofeng;Gao Jianshe(School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学机械与动力工程学院,河南郑州450001

出　　处：《机械传动》2022年第6期45-51,共7页Journal of Mechanical Transmission

基　　金：国家自然科学基金(U1304510);河南省高等学校重点科研项目(19A460008)。

摘　　要：针对球面并联机构应用于机器人仿生领域时出现的耦合度高、控制不便、灵活性不足等问题,提出了一种具有半解耦特性的新型3分支球面并联机构。基于螺旋理论对机构进行了自由度分析,通过矢量法求解了机构运动学正反解并分析了机构的解耦特性。该机构具有绕X轴、Y轴、Z轴转动的3个自由度,其中,绕Z轴的转动仅由1个分支控制,其余两分支共同控制机构做绕X轴、Y轴的运动。基于微分变换法得到雅可比矩阵并讨论了奇异位形。以奇异位形和杆件干涉为约束条件,采用边界搜索法确定了机构的工作空间。基于机构的解耦特性提出了一种具有解耦系数的全域均值灵巧度,以工作空间和全域均值灵巧度为优化目标,采用粒子群优化算法(PSO)对机构结构参数进行了尺度综合。机构优化后,工作空间增大且在该空间内运动性能良好。研究为球面并联机构的样机设计和其他半解耦机构的尺度综合提供了理论依据。In order to solve problems of high coupling degree,inconvenient control and insufficient flexibility when spherical parallel mechanism is applied in the field of robot bionics,a novel three-branch spherical parallel mechanism with semi-decoupled characteristics is proposed.Based on the screw theory,the degree of freedom(DOF)of the mechanism is analyzed.The forward and inverse kinematics solutions of the mechanism are solved by the vector method and the decoupling characteristics of the mechanism are analyzed.The mechanism has a 3-DOF to rotate around the X axis,Y axis,Z axis,and the rotation around the Z axis is controlled by only one branch,while the other two branches jointly control the mechanism to move around the X axis,Y axis.Jacobian matrix is obtained based on differential transformation method and singular configuration is discussed.The workspace of the mechanism is determined by the boundary search method with singular configuration and bar interference as constraints.Based on the decoupling characteristics of the mechanism,a global mean dexterity with decoupling coefficient is proposed.Taking the workspace and global mean dexterity as the optimization goals,the particle swarm optimization algorithm(PSO)is used to synthesize the structure parameters of the mechanism.After the optimization,the workspace is enlarged and the motion performance in this space is good,which provides a theoretical basis for the prototype design of the spherical parallel mechanism and the scale synthesis of other semi-decoupling mechanisms.

关 键 词：球面并联机构 螺旋理论 雅可比矩阵 尺度综合 

分 类 号：TH112[机械工程—机械设计及理论]