工业机器人绝对定位误差补偿方法

Absolute Positioning Error Compensation Method for Industrial Robot

现场环境下工业机器人连续作业运行容易导致定位漂移问题,利用外部高精度测量系统获取其末端执行器精确三维位置信息是机器人绝对定位误差的有效补偿方式。针对误差补偿三维测量高效率、高精度、高适应性要求,提出了一种基于工作空间测量定位系统的工业机器人精度补偿方法。利用测量定位系统的动态特性,设计了针对机器人工作轨迹空间的网格划分策略,根据定位误差实际分布情况调整网格边长,通过采集网格节点绝对定位误差矢量值,研究了反距离加权算法以完成轨迹关键节点定位误差矢量的插值计算,最终完成末端执行器绝对定位误差补偿。试验结果表明,所研究方法实时性好、效率高,安装20kg负载补偿后机器人绝对定位误差平均值由1.36mm降为0.19mm,提升了约86%,能够显著改善工业机器人现场作业精度。

When an industrial robot is operational continuously in industrial field,the position of the end effector would drift.Using external high-precision measurement system to get the accurate 3D position coordinate of the end effector is an effective method of compensating the absolute positioning error of the robot.The measurements required efficient,high-precision and adaptability,to deal with these problems,in this paper,an error compensation method of industrial robot based on workspace measurement and positioning system is proposed.Based on the dynamic performance of the system,a meshing strategy for robot workspace is designed.The grid edge length could be adjusted according to the actual distribution of positioning errors.After collecting the absolute positioning error vector values of grid nodes,for the interpolation calculation of the position error vector at key trajectory nodes,the inverse distance weighting algorithm is studied to realize the compensation of the position errors of the end effector.The experimental results exhibit that after installing 20kg load,the average absolute positioning error of the robot is reduced from 1.36mm to 0.19mm,the absolute positioning accuracy of the robot is improved by about 86%after compensation.It indicates that this proposed highefficient method can significantly improve the site operation accuracy of the industrial robot.