The coordinate measurement principal of flexible and on-line visual inspection system based on universal industrial robot is introduced.In order to obtain closed-loop and accurate coordinate transformation

distance accuracy calibration model of robot is established by adopting MD—H convention.The same calibration points used to compensate link parameters are registered to the laser tracker coordinate based on singular value decomposition.The transformations from the robot base frames to the car fame are determined.Experiment results show that the method is practical with simple operation and satisfactory precision of ±0.30 mm.