Robot base frame calibration method based on dual quaternion

GAO Yuan, LIU Xiaoping, WANG Gang, LIANG Jiangang

(School of Automation, Beijing University of Posts and Telecommunications, Beijing 100876, China)

Abstract: Aiming at the problem of unified coordinate system involved in the robot calibration with the help of laser tracker, the transformation relation between robot nominal base frame and the fitting base frame of spatial geometric method by laser tracker was researched, a calibration method of robot base frame using dual quaternion was proposed and applied. The 7DOF serial robot kinematics model was established by the productofexponential formula, and calibration model for robot base frame using dual quaternion was derived. The results indicate that the calibration method can calculate the rotation and translation of the calibration equation at one time, overcome the error transfer in the traditional posestep calculation process and improve the calibration accuracy directly. The calibration method is useful to other problem that formulates in the same mathematical form, such as robot handeye system calibration and multirobot coordination.

Key words: robot base frame; calibration; dual quaternion