Kinematic Calibration of Serial Manipulators Using Relative Measurements

In this paper, an approach to the kinematic calibration of serial manipulators with six revolute joints in general using relative position and orientation measurements is presented, and a Thermo CRS A465 is used for illustration. The definition of the errors used for the calibration process are first introduced, then the kinematic model that describes the manipulator pose (position and orientation) using the kinematic parameters is discussed. The pose of the manipulator is specified by six independent position and orientation parameters. The kinematic model presented is based on the nominal Denavit-Hartenburg (DH), along with the kinematic error model that describes the changes in the manipulator pose to the relative errors between the nominal and actual DH parameters. The results of two simulated measurements using the position and orientation are presented, and the performance of the kinematic error identification technique is discussed.