Large valve sealing surface in-position measurement robot and its parameter identification

Aiming at the current problems of low accuracy and low automation of large gate valve sealing surface measurement, an on-position measurement system specifically for large gate valve sealing surface measurement is studied and the calibration method to improve the accuracy of the robot is analyzed. The error caused by the flexible deformation of the connecting rod is considered. First, the DH model of the robot is established, and then the model is updated according to different error sources, and the iterative least squares method is used to calibrate the geometric error parameters and the deformation error parameters of the robot segmentally. The flatness variation of the standard marble plane measured by the calibrated robot is reduced from 34.9μm to 17μm; the error of the gate valve sealing surface model angle measured by the robot is 0.63% compared with the CMM, and the opening dimension can be obtained compared to the CMM.