Abstract:Aiming at the problem when using ArUco tags are not accurate in long distance measurement, an improved pose estimation method is proposed. First, an array feature ring is designed on the basis of ArUco marker, and the accuracy of center detection is judged based on constant cross ratio. Secondly, the linear fitting relationship between the ArUco marker corner and the center of the array ring is established by using the weighted least square method to realize the corner correction. Finally, EPnP+LM algorithm is used for pose estimation. A mechanical arm visual positioning system was designed to verify the effectiveness of the proposed method. Experimental results show that the maximum translation error of the proposed method is 8.72mm and the maximum rotation error is 1.78° in the measuring range of 2.5-4m, while the maximum translation error of the traditional method is 36.42mm and the maximum rotation error is 4.65°. This method is superior to the traditional method in the accuracy of pose measurement.