A simple calibration method for line-structured light vision sensor based on planar target of different positions

Accurate, efficient and robust calibration for the line-structured light vision sensor in 3D vision measurement is a significant procedure for that it is the foundation of the subsequent 3D-reconstruction. A simple and high-precision calibration method for the line-structured light vision sensor based on the planar target is proposed in this paper. The presented approach consists of three main steps. In the first step, the camera is calibrated to obtain the intrinsic parameters. In the second step, the camera coordinate of the light plane feature point is acquired through combining the constraint condition between the camera coordinate and pixel coordinate on the perspective projection model of the camera with the special equation of the planar target. In the third step, the light plane is fitted with the obtained light plane feature points based on the least square fitting. Compared with the cross-ratio invariability method, the proposed method achieve calibration with simply extracting the centerline of the light stripe. A calibration accuracy of 0. 080mm is achieved using the proposed method, which is comparable to that of the cross-ratio invariability method. This calibration method satisfies the requirement of high-accuracy for 3D vision measurement.