一种基于D-H参数的7自由度机械臂机构精度综合方法研究  

Research on the precision synthesis method of a 7 DOF manipulator based on D-H parameters

作　　者：高跃 房立金 姜雪洁 巩云鹏[1] Gao Yue;Fang Lijin;Jiang Xuejie;Gong Yunpeng(SchoolofMechanical Engineering&Automation,Northeastern University,Shenyang110819,China;Schoolof Robot Science&Engineering Northeastern Unicersily,Shenyang 110819,China)

机构地区：[1]东北大学机械工程与自动化学院,沈阳110819 [2]东北大学机器人科学与工程学院,沈阳110819

出　　处：《仪器仪表学报》2022年第4期137-145,共9页Chinese Journal of Scientific Instrument

基　　金：辽宁省中央引导地方科技发展专项(2021JH6/10500132)资助。

摘　　要：提出了一种基于最佳精度模型的机械臂机构精度综合的方法,利用遗传算法对D-H参数公差优化分配,为机械臂的精度设计提供理论依据。以一种基于双电机伺服驱动关节的7自由度协作机械臂为研究对象,机械臂的几何定位精度的设计目标为1.4 mm,建立该型机械臂末端执行器的几何定位误差模型;对参数误差进行敏感性分析,找出对机械臂末端执行器几何定位误差影响相对较大的参数误差;根据最佳精度数学模型,利用遗传算法对D-H参数公差优化分配;经过对误差仿真计算分析,机械臂的最大几何定位误差为1.226 7 mm,均值为0.485 9 mm,方差为0.216 5 mm,满足设计要求。为该机械臂的制造装配提供了理论参考依据。与基于最小成本模型的精度综合法相比,提出的精度综合方法不需要统计加工制造成本信息,能够确保机械臂的设计精度满足设计要求,可用于单个或者小批量生产制造机械臂的精度设计。A precision synthesis method of manipulator mechanism based on the optimal precision model is proposed. The genetic algorithm is used to optimize the tolerance allocation of D-H parameters, which provides a theoretical basis for the precision design of the manipulator. Taking a 7 DOF cooperative manipulator based on the dualmotor servo drive joint as the research object, the geometric positioning accuracy of the manipulator is designed to be 1.4 mm. The geometric positioning error model of the end-effector of the manipulator is established. The sensitivity analysis of parameter errors is implemented to find out the parameter errors which have a relatively great influence on the geometric position errors of the end-effector of the manipulator. According to the optimal precision mathematical model, the genetic algorithm is used to optimize the tolerance allocation of D-H parameters. After error simulation calculation and analysis, the maximum geometric positioning error of the manipulator is 1.226 7 mm, with an average value of 0.485 9 mm and variance of 0.216 5 mm. This result meets the design requirements and provides a theoretical reference for the manufacturing and assembly of the manipulator. Compared with the precision synthesis method based on the minimum cost model, the precision synthesis method proposed in this paper does not need statistical manufacturing cost information and can ensure that the design precision of the manipulator meets the design requirements. It can be used for the precision design of single or small-batch manufacturing manipulators.

关 键 词：7自由度机械臂 几何定位误差 敏感性分析 精度综合 遗传算法 

分 类 号：TH115[机械工程—机械设计及理论]