A novel method to calibrate the rotation axis of a line-structured light 3-dimensional measurement system

Rotation axis calibration is the key to line-structured light 3-dimensional (3D) measurement. The traditional calibration method based on circle fitting only uses the position information of the calibration target and ignores the orientation information, which is easily affected by noise. This paper proposes a new calibration method combining the orientation and position information to improve the calibration accuracy. Compared with the circle fitting method, the added orientation information makes the description of rotation more complete. On this basis, an improved extrinsic parameters estimation method is proposed to obtain more accurate position and orientation information of the target, which further improves the calibration accuracy. The experiment results show that, the radius error is reduced by about 90% and the standard deviation of radius error is reduced by about 40% compared with the traditional circle fitting method.