基于激光跟踪仪的机器人运动学参数标定方法

Calibration of Robot Kinematic Parameters Based on Laser Tracker

工业机器人的连杆参数误差是影响其绝对定位精度的最主要因素,为改善机器人的绝对定位精度,借助了高精度且可以实现绝对坐标测量的先进测量仪器——激光跟踪仪,以及功能强大的CAM2 Measure 4.0配套软件,从机器人自身的运动约束出发,构建起实际的D-H模型坐标系,进而对运动学参数进行了修正,获得了关节变量与末端法兰盘中心位置在基坐标系下的准确映射关系.结果表明,标定后的平均误差及均方根误差均改善了400/0以上,且该方法易于实现,通用性强,能明显改善精度.

Link parameter errors of the industrial robot contribute to the most influence on its accuracy. In order to improve the accuracy of the robot, a laser tracker, which can implement highly accurate measurement and absolute distance measurement （ ADM）, as well as the corresponding CAM2 Measure 4.0 software were employed. Based on the movements constrain of the robot itself, the actual D-H model coordinate frames were rebuilt. Accordingly, the kinematic parameters were identified and precise mapping from the joint variables to the center position of the end-effector in the base frame was obtained. Results show that mean error and root mean sguare error are improved more than 40%. The proposed calibration method is practical and generic. In addition, it can achieve better accuracy.