基于3-RRR非对称球面并联机构的假肢肩关节机构优化设计  

Optimization design of prosthetic shoulder joint based on three-RRR asymmetric spherical parallel mechanism

作　　者：陈文斌 张宇霖 付豪 范翔 熊蔡华 梁杰俊一 CHEN WenBin;ZHANG YuLin;FU Hao;FAN Xiang;XIONG CaiHua;LIANG JieJunYi(State Key Laboratory of Digital Manufacturing Equipment and Technology,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学机械科学与工程学院,数字制造装备与技术国家重点实验室,武汉430074

出　　处：《中国科学：技术科学》2022年第9期1434-1446,共13页Scientia Sinica(Technologica)

基　　金：国家重点研发计划(编号:2018YFB1307201,2020YFC2007802);国家自然科学基金(批准号:52075191,U1913205,52027806,U1913601,52005191);华中科技大学学术前沿团队资助项目;湖北省自然科学基金(编号:2020CFB424)资助

摘　　要：由于具有紧凑的空间布局和良好的结构刚度等特点,3自由度球面并联机构在肩、腕等多自由度关节的设计方面具有潜在的优势,但现有球面机构设计方法未结合人体肩关节工作空间呈非对称形貌、灵巧运动能力呈非对称分布的特点开展针对性的设计.本文以3-RRR非对称球面并联机构为原型,开展假肢肩关节机构参数优化研究,旨在改善非对称球面并联假肢肩关节机构的运动学性能.为此,首先确定了机构的参数化模型,在推导机构运动学正反解和速度雅可比矩阵的基础上,以机构工作空间对人体肩关节工作空间的覆盖程度最大、机构灵巧性最高和输入轴最大力矩最小为目标对机构的参数进行多目标优化设计.利用基于三角模糊数的模糊层次分析法计算各个指标的权重,以加权求和法从优化求解的Pareto解集中筛选出满足需求的最优机构参数.根据该最优机构参数设计的假肢肩关节机构,其工作空间能够有效覆盖人体肩关节的工作空间.和现有对称配置的球面并联机构相比,其机构灵巧性和最大关节力矩得到有效改善.研究工作可为假肢肩关节的设计与应用提供理论基础.Due to its compact spatial layout and good structural stiffness,the three-DOF spherical parallel mechanism has potential advantages in designing multidegree of freedom joints,such as the shoulder and wrist joints.However,existing spherical mechanism design methods do not consider the characteristics of the asymmetric shape of the human shoulder workspace and the asymmetric distribution of dexterous motion ability.Considering the three-RRR asymmetric spherical parallel mechanism as the prototype,this paper investigates the parameter optimization of the prosthetic shoulder joint mechanism to improve the kinematic performance of the asymmetric spherical parallel prosthetic shoulder joint mechanism.First,the parametric model of the mechanism is determined.Based on the derivation of the forward and inverse kinematics solution and the Jacobian velocity matrix,the multiobjective optimization design of the mechanism parameters is with the goal of the maximum coverage of the mechanism workspace to the human shoulder workspace,the maximum dexterity of the mechanism,and the minimum torque of the input shaft.The weight of each index is calculated by the fuzzy analytic hierarchy process based on a triangular fuzzy number,and the optimal mechanism parameters are selected from the Pareto solution set by the weighted summation method.The working space of the bionic shoulder joint mechanism designed according to the optimal mechanism parameters can effectively cover the working space of the human shoulder joint.Compared with the existing parallel mechanisms,its dexterity is improved,and the maximum joint torque is reduced.Thus,this study can provide a theoretical fundament for the design and application of prosthetic shoulder joints.

关 键 词：假肢肩关节 3-RRR球面并联机构 多目标优化设计 模糊层次分析法 

分 类 号：TH112[机械工程—机械设计及理论]