Kinematic Calibration of Serial Manipulators Using Relative Measurements

Kinematic calibration is necessary to enhance the accuracy of robotic manipulators. It is typically desired to perform this task in both a cost-effective and time-efficient manner. Many techniques exist in the literature that achieve both goals. In this thesis, a novel model-based kinematic calibration method using relative measurements is developed and implemented, which has proven to be useful for optical measurements, and is capable of achieving the same level of accuracy as the typical absolute measurement methods. Furthermore, the effects of measurement noise, the number of measured poses, and the best pose configurations for kinematic calibration are investigated. Both a Thermo CRS A465 and a 7 DOF WAM Arm were used in this thesis. The results for the WAM Arm lead to a significant improvement in the end-effector pose accuracy. The implication is that the relative measurement concept is a valid tool for model-based kinematic calibration of serial manipulators.