工业机器人机械零位的敏感性分析与实验研究

Sensitivity Analysis and Experimental Research on Mechanical Zero Position of Industrial Robot

针对工业机器人的定位精度较差以及标定不准等问题,课题组从机器人机械零位(预标定)入手,以LR20型六自由度工业机器人为研究对象,借助激光跟踪仪对机械零位进行测量,采用逐层递进的方式,从肉眼观察、塞尺触碰和参数辨识三个维度去实现回零。首先推导出机械零位误差模型,并用MATLAB的Simulink模块分析出末端位置敏感度,然后在机器人机械零位误差测试平台上完成多梯度修正实验,最后对机器人控制程序中的零位参数进行补偿。在三次回零后分别进行20点的验证实验,结果发现绝对位置平均误差改善了52%、88%、95%以上,明显地改善了机器人定位精度,验证了回零方案的可行性,同时为后续机器人标定以及实时补偿工作奠定了基础。

Aiming at the problems of poor positioning accuracy and inaccurate calibration of industrial robot,the research group starts with the robot mechanical zero position(pre calibration),takes LR20 six degree of freedom industrial robot as the research object,measures the mechanical zero position with the help of laser tracker,and realizes zero return from the three dimensions of naked eye observation,feeler gauge touch and parameter identification in a layer by layer manner.Firstly,the mechanical zero position error model is derived,and the end position sensitivity is analyzed with the Simulink module of MATLAB.Then the multi gradient correction experiment is completed on the robot mechanical zero position error test platform.Finally,the zero position parameters in the robot control program are compensated.After three zeroing,20 point verification experiments are carried out respectively.The results show that the average absolute position error is improved by more than 52%,88%and 95%,which significantly improves the positioning accuracy of the robot,verifies the feasibility of the zeroing scheme,and lays a foundation for subsequent robot calibration and real-time compensation.