服务机器人小型关节回差测量的实验研究

Experiment research on hysteresis measurement of the small-size joint of service robot

小型关节作为机器人姿态控制的核心部件,对机器人的性能有直接影响。回差是表征小型关节传动精度的关键指标,其测量和评价是提高小型关节性能的基础。迄今对小型关节回差的测量主要基于其主要组件减速器进行,而对小型关节的整体回差研究几乎为空白。为探究小型关节整体回差的产生机理及其基本规律,依托所研发的测试机对小型关节的整体回差进行了实验研究,在对小型关节的结构组成、整体回差的组成和测量模型分析的基础上对A、B、C 3款小型关节进行4项动态测量实验,发现几何回差和弹性回差是影响关节整体回差的主要因素;转速对其整体回差的影响小于弹性变形,在负载相同与不同转速下测量的结果相差在0.05°;并发现在一定条件下,关节的动态回差与负载近似呈线性关系;最后对关节整体回差进行了静态测量实验,并与动态测量实验进行了对比,发现静态测量结果小于动态测量,相差在0.1°左右。对小型关节整体回差测量的实验研究为建立面向小型关节的全局质量评价体系提供了坚实的基础。

As the core component for robot posture control,small-size joints have a direct influence on the robot performance.Hysteresis is a key index characterizing the transmission precision of small-size joint.Hysteresis measurement and evaluation are the foundation for improving the performance of small-size joint.Up to now,the hysteresis measurement of small-size joint is performed mainly based on its main component—reducer.Little research has been done on the overall hysteresis of the small-size joint.In order to investigate the generation mechanism of total hysteresis of small-size joint and its basic law,an experiment study on the overall hysteresis of the small-size joint was conducted based on the developed tester.Based on the analysis on the structural composition of small-size joint,the composition of total hysteresis and the measurement model,4 dynamic measurement experiments on small-size joints A,B and C were conducted.It is found that the geometric hysteresis and elastic hysteresis are the main factors influencing the total hysteresis of the joint.The revolution speed has less influence on the total hysteresis than elastic deformation.Under the conditions of the same load and different revolution speeds,the difference of the measurement results is 0.05°.It is also found that under certain condition,the dynamic hysteresis and load of the joint show an approximate linear relationship.Finally,a static measurement experiment on the total hysteresis of the joint was conducted,and the result was compared with that for dynamic measurement experiment.It is found that the static measurement result is less than the dynamic measurement result,and the difference is about 0.1°.The experiment study on the total hysteresis measurement of small-size joint in this paper lays a solid foundation for establishing the overall quality evaluation system facing to small-size joints.