Calibration of line-structured light vision sensor based on free-placed single cylindrical target

This paper proposes a novel calibration method for the Line-structured Light Vision Sensor (L-LVS) based on a straight cylindrical target that can be free placed. The cylindrical target is placed at least once in the measurement space. The camera captures the image of the cylindrical target and the light stripe. Based on the geometric properties of the cylinder and vanishing points, we calculate the 3D centers of the cylindrical end circles and reconstruct the cylindrical quadric surface. Then, multiple 3D points on the cylindrical surface are obtained according to the perspective projection relationship, which finally allows for the reconstruction of the light plane. Both simulation and real experiments show that the proposed method is effective. In the real experiments, the measurement accuracy of a L-LVS based on the proposed calibration method achieves 0.056 mm, when the measuring distance is about 400 mm. Due to the small-size and pose-unconstrainted target, our calibration method is superior to be applied in the confined measurement space in the wild.