Significance Statement
Existing calibration methods for a line-structured light vision sensor usually require solving the light plane equation by combining the characteristic points of the target and the image of the light stripe on the target. We propose a novel method for calibration of the line-structured light vision sensor that only requires the image of the light stripe on the target using a movable parallel cylinder target. The main procedure of the proposed method is as follows: the images of the light stripe on the parallel cylinder target are first fitted. The corresponding equations between two ellipses in space and their projected images are then established according to the perspective projection transformation. Given the constraint conditions that the short axis of the ellipse is equal to the diameter of the cylinder, the light plane equation is solved. Finally, the optimal solution of the light plane equation is obtained by nonlinear optimization method. The proposed algorithm is verified by simulation and physical experiments. In the physical experiment, the field of view of the line-structured light vision sensor is about 500 mm×400 mm, and the measurement distance is about 700 mm. When the proposed method is used, a calibration accuracy of 0.07 mm is achieved, which is comparable to that when planar targets are used.
Journal Reference
Optics Express, 23,Issue 23,pp. 29896-29911, (2015)
Zhen Liu, Xiaojing Li, Yang Yin
Key Laboratory of Precision Opto-mechatronics Technology, Ministry of Education, Beihang University, No.37 Xueyuan Rd, Haidian District, 100191, Beijing, China.
Abstract
A novel calibration method for the line-structured light vision sensor that only requires the image of the light stripe on the target using a movable parallel cylinder target is proposed in this paper. The corresponding equations between two ellipses obtained from the intersection of the light stripe and the target and their projected images are established according to the perspective projection transformation, and the light plane equation is solved based on the constraint conditions that the minor axis of the ellipse is equal to the diameter of the cylinder. In the physical experiment, the field of view of the line-structured light vision sensor is about 500 mm × 400 mm, and the measurement distance is about 700 mm. A calibration accuracy of 0.07 mm is achieved using the proposed method, which is comparable to that when planar targets are used.
© 2015 Optical Society of America.
Go To Optics Express