1.Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China
2.State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China
3.Shanghai Aircraft Manufacturing Co. Ltd, Shanghai 200436, China
Abstract：A general pose testing method of industrial robot is proposed. The basic principle is to use laser tracker to measure the robot’s absolute pose indirectly by measuring 4 reference points fixed on its end, and to compare the real pose with the command pose to test the pose accuracy and repeatability. In this process, the reference points’ coordinates and the robot base coordinate system are calibrated synchronously by multi-pose constrain and a nonlinear calibration algorithm is designed. This testing method is illustrated with a KUKA KR210 R2700 industrial robot with a drilling end effector. The pose accuracy and repeatability of the robot are 0.3 mm and 0.06 mm, which are in accordance with the nominal index. And the coordinate deviation of the tool center point (TCP) from direct measurement is less than 0.015 mm. It is obvious that the testing method is accuracy enough for the requirements of robot pose testing and does not require special mechanical tools. The calibration residual is reduced to 0.35 mm by the nonlinear calibration method. It proves the calibration method has good robustness and can effectively reduce the error caused by inaccurate kinematics model of the robot.
2018, Vol. 39 
