航空学报 > 2022, Vol. 43 Issue (5): 625569-625569   doi: 10.7527/S1000-6893.2021.25569

机器人先进制造与装配技术专栏

考虑关节回差的工业机器人精度补偿方法

田威1, 程思渺1, 李波1, 廖文和2   

  1. 1. 南京航空航天大学 机电学院, 南京 210016;
    2. 南京理工大学 机械工程学院, 南京 210094
  • 收稿日期:2021-03-25 修回日期:2021-05-12 发布日期:2021-06-29
  • 通讯作者: 田威 E-mail:tw_nj@nuaa.edu.cn
  • 基金资助:
    国家自然科学基金(52005254,52075256);国家重点研发计划(2018YFB1306800,2019YFB1310101);国防基础科研项目(JCKY2018605C002)

An error compensation method of an industrial robot with joint backlash

TIAN Wei1, CHENG Simiao1, LI Bo1, LIAO Wenhe2   

  1. 1. College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
    2. School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
  • Received:2021-03-25 Revised:2021-05-12 Published:2021-06-29
  • Supported by:
    National Natural Science Foundation of China (52005254, 52075256); National Key R&D Program of China (2018YFB1306800, 2019YFB1310101); National Defense Basic Scientific Research Program of China (JCKY2018605C002)

摘要: 工业机器人由于绝对定位精度低的缺点一直难以应用于航空航天高精制造领域。影响机器人定位误差的因素较多,对精确建立其误差模型提出了严峻的挑战。现有的建模方法通常将机器人定位误差与其位姿关联,忽略了同一位姿下关节回差对其定位误差的影响。为提高工业机器人绝对定位精度,提出了一种考虑关节回差的工业机器人误差相似度精度补偿方法。基于改进的Denavit-Hartenberg模型建立了包含机器人几何误差、坐标系误差和传动误差的综合辨识模型,利用最小二乘法辨识了关节回差。根据辨识得到的关节回差等参数构建了误差相似度模型,使用3种型号的机器人验证了该方法对提高机器人绝对定位精度的可行性和通用性,最终通过KUKA KR500-3机器人进行了制孔试验验证。试验结果表明,该方法相较于传统方法将机器人定位误差降低了约0.1 mm,精度提高了30%以上,制孔孔位精度从0.701 mm提升至0.134 mm,为有效提高工业机器人的绝对定位精度提供了一种技术手段。

关键词: 工业机器人, 关节回差, 误差相似度, 参数辨识, 精度补偿

Abstract: Because of the low absolute positioning accuracy, industrial robot is difficult to be used in aerospace high precision manufacturing. There are many factors that affect the positioning error of robot, which poses a severe challenge to the accurate establishment of its error model. The existing modeling methods usually associate the robot's positioning error with its pose, ignoring the influence of joint backlash on its positioning error in the same pose. In order to improve the absolute positioning accuracy of industrial robot, an error similarity accuracy compensation method for industrial robot considering joint backlash is proposed. Based on the improved Denavit-Hartenberg model, a comprehensive identification model including robot geometric error, coordinate system error and transmission error is established, and the joint backlash is identified by using the least square method. According to the identified parameters such as joint backlash, the error similarity model is constructed. Three types of robots are used to verify the feasibility and universality of the method for improving the absolute positioning accuracy of the robot. Finally, the drilling experiment is conducted by KUKA KR500-3 robot. The experimental results show that, compared with the traditional method, the positioning error of the robot is reduced by about 0.1 mm, the accuracy is improved by more than 30%, and the hole position accuracy is improved from 0.701 mm to 0.134 mm. From these results it is concluded that this method provides a technical means to effectively improve the absolute positioning accuracy of industrial robot.

Key words: industrial robot, backlash, error similarity, parameter identification, error compensation

中图分类号: