Three planes method on measuring and compensation of parallel robot

Abstract

Precise calibrations are necessary to satisfy requirements of a parallel robot.To accomplish this,a coordinate measuring machine(CMM) was adopted and a novel measurement method-the three planes method—was studied.The plane equation was measured to gain the position of the parallel robot.The error equations of a six degrees of freedom(DOF) parallel robot were established.Error parameters for the three planes method were obtained in order to implement error measurement and error compensation.The method was verified with a six DOF parallel manipulator with parallel tracks.The results show that after calibration,the error between the nominal and measured poses achieve the same level as the manipulator′s repeatability,which is much improved than without calibration.