Bin Liu, Qian Qiao and Fangfang Han* Pages 1 - 8 ( 8 )
Background: 3D laser scanner is a non-contact active-sensing system which benefits a myriad of applications. Many patents conduct thorough research on the technologies for calibrating 3D laser scanner. The precise calibration method is essential to the measuring accuracy of the 3D laser scanner. The system model contains the three categories of the parameters to be calibrated, the camera intrinsic parameters, distortion coefficients and the light plane parameters. Typically, the calibration process needs two steps. The calibration of the camera intrinsic parameters and distortion coefficients could be operated based on Zhang’s method at first. Then 3D feature points on the light plane should be precisely formed and extracted. Finally, the points would be used to calculate the light plane parameters.
Methods: In this paper, a rapid calibration method was presented. Without any assistant adjustment equipment, only one coplanar reference target is used. Using a group of captured images of the coplanar reference target placed in the field of view arbitrarily, the calibration can be fulfilled in one step. Based on the constraint from the planes formed by the target in different directions and the camera imaging model, a large amount of 3D points on the light plane can be easily obtained. The light plane equation in the camera coordinates system can be gathered by executing plane fitting to the 3D points.
Results: During the experimental process, the developed 3D laser scanner was calibrated by the proposed method. Then the measuring accuracy of the system is verified in the depth direction with 1mm shifting motion generated by precision translation stage. The average value of the measured distances is 1.010mm. And the standard deviation is 0.008mm.
Conclusion: Experimental results prove that the proposed calibration method is simple and reliable.
3D laser scanner, structured light, calibration, coplanar target, system model, light plane
Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems, Tianjin City, 300384, Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems, Tianjin City, 300384, Tianjin Key Laboratory for Control Theory & Applications in Complicated Systems, Tianjin City, 300384