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.