Abstract: In order to describe the robot poses in the world coordinate system of the off-line programming system, a precise calibration method of robot's base frame using dual quaternion was proposed. Firstly, on the basis of the robot kinematics model established by the product-of-exponential formula, a calibration model for robot's base frame using dual quaternion was derived, which obtains the unified description of robot poses between the world coordinate system and the robot's base frame. Then, with the dual quaternion constraints, the Lagrangian multiplier method was employed to obtain the optimum pose in solving a minimum-variance problem. Finally, calibration experiment on a serial 6-DOF industrial robot was performed, which indicated that the method is effective and easier to get solutions for robot's base frame calibration in industry environment. The calibration algorithm can not only provide theoretical reference but also provide useful advices to robot hand-eye system calibration and multi-robot coordination.

Key words: robot base frame, world coordinate system, calibration, dual quaternion