The Measurement Method of Target Pose Based on Feature Points Position Calibration

Aiming at the problem of measurement error caused by the deflection of the target and the camera in the image subgrade settlement monitoring system due to vibration, a pose measurement method based on 4 feature points position calibration was proposed. Firstly, the operational principle of the image based settlement monitoring method was introduced and the components and working model of the online surface settlement monitoring system were described. Then, different from the traditional feature points a pose measurement system with the 4 feature points target surface is designed, and using special feature point to calibrate the target surface. Finally, the method of target pose based on rectangular side length known was proposed. Experimental results show that the angle error of this method is smaller than that of the iterative method, the relative error of the pose solution is reduced by 1.2 %. When the deflection angle is less than 2°, the method solves the rotation angle error of less than 0.09°, the relative angular error is 1.003 %. The time and accuracy of the proposed method can meet the requirements of the monitoring system, it can also be applied to scenes in the monitoring system that require real-time calibration of the camera and target. Copyright © 2020 Acta Automatica Sinica. All rights reserved.