Kinematic Calibration Of A Manufacturing Steel-joints Robot—Trivariant-b

This dissertation deals with the kinematic calibration of a5DOF hybrid robot-TriVariant-B, including position analysis, error modeling, parameter identification,error compensation, computer simulation and experimental verification. Thefollowing creative work has been completed.1．The inverse position analysis is carried out by the method of vector chain. Andthe forward position of2DOF parallel mechanism is formulated using the method ofNewton-Raphson.2．On the basis of inverse and forward position analysis, the geometric errormodel of parallel mechanism of TriVariant-B robot is formulated by the method ofvector chain. In this process the key point is that geometric error of passive joint ofcan be divided into two parts-permitted error and restricted error. This kind of methodis proved to be simple and universal.3．The identification model using laser tracker is achieved, and then a three-stepkinematic calibration is carried out,(1) to identify the error of the measuringcoordinate;(2) to identify the relative and absolute home errors of each limb;(3) toidentify the rest source errors using the laser tracker. The confidence degree ofidentified results can be enhanced in this algorism for the errors to be identified ineach step are in the same order.4．The error compensation method is carried out by modifying the inputs of thesystem. According to the features of TriVariant-B and the measuring method, themeasuring trajectory is determined. Computer simulation results show that the methodis robust. The feasibility and effectiveness of the proposed kinematic calibrationmethod is verified by experimental results.