A screw axis identification method for serial robot calibration based on the POE model

Purpose - The purpose of this paper is to propose a screw axis identification (SAI) method based on the product of exponentials (POE) model, which is concerned with calibrating a serial robot with m joints equipped with a stereo-camera vision system. Design/methodology/approach - Different from conventional approaches, like the circle point analysis (CPA) or the system theoretic method which must collect a great deal of data, the identification of the joint parameters for the proposed method only needs to measure m + 1 times for n (n >= 3) target points mounted on the manipulator end-effector. Findings - In this approach, the joint parameter, called a screw or twist, together with the actual value of joint angle can be obtained by linearly solving a closed-form expression. Further, this method avoids calibrating the hand-eye relationship and the exterior parameter of the robot. Originality/value - Finally, the stability and accuracy of the SAI method are evaluated by simulation experiments, and it is also verified well in practical experiments.