提出一种利用激光跟踪仪标定机器人工具坐标系的方法。利用激光跟踪仪确定机器人的基坐标系,将机器人基坐标系与激光跟踪仪的测量坐标系统一。通过机器人运动学方程获得机器人末端连杆坐标系相对基坐标系的变换关系,利用激光跟踪仪测量拟合得到机器人工具坐标系,利用坐标变换初步确定机器人工具参数。通过机器人单轴旋转运动对工具坐标系原点进行修正,最终确定工具参数。最后通过机器人重定位运动对误差进行计算。实验结果表明,修正后x,y,z坐标的RMS(root mean square,均方根)误差分别为0.1271,0.1413和0.1174mm,精度是修正前的2.5倍。
A robot tool coordinate system calibration method based on the laser tracker is presented. The robot base coordinate system is determined by the laser tracker, and then the coordinate systems of the robot and laser tracker measurement are unified. By using the robot kinematic equations, the transformation relationship between the robot end effecter coordinate system and its base coordinate system is obtained. The robot tool coordinate system is measured and fitted by the laser tracker, and then the parameters of TCF (tool control frame) are preliminarily established using the coordinate transformation. Using the single axis rotation of the robot, the TCP (tool centre point) is corrected with the TCF and then is ultimately determined. Finally, the errors are calculated by the robot's reorientation movement. Experiment results show that the RMS errors for x, y and z coordinates after correction are 0. 127 1, 0. 141 3 and 0. 117 4 mm, respectively; the accuracy is 2. 5 times as much as that before correction.