Monocular vision calibration method of the stereo target for robot pose measurement

The full pose measurement of industrial robot was valuable to robot assembly and robot calibration. In order to decrease the influence of ambient light and expand the target movement space, an active target was designed, and a method of the target calibration based on monocular vision was proposed. The initial pair was selected to enhance the accuracy of the translation vector which was decomposed from essential matrix. Then, images were added one by one and they all were used in the bundle adjustment to compute the high accuracy of 3D structure in the whole scene. Further, the points of the calibration board was adopted as the scale factor, and all the information was transformed into metric. The experimental results demonstrated that the 3D reconstruction precision is less than 0.035 mm, and the method could satisfy the requirement of stereo target calibration. Besides, the robot pose is effectively identified, and the position accuracy is improved by 37%.