Design and Analysis of High-Accuracy Telecentric Surface Reconstruction System Based on Line Laser

Abstract

Non-contact measurement technology based on triangulation with cameras is extensively applied to the development of computer vision. However, the accuracy of the technology is generally not satisfactory enough. The application of telecentric lenses can significantly improve the accuracy, but the view of telecentric lenses is limited due to their structure. To address these challenges, a telecentric surface reconstruction system is designed for surface detection, which consists of a single camera with a telecentric lens, line laser generator and one-dimensional displacement platform. The designed system can reconstruct the surface with high accuracy. The measured region is expanded with the used of the displacement platform. To achieve high-accuracy surface reconstruction, we propose a method based on a checkerboard to calibrate the designed system, including line laser plane and motor direction of the displacement platform. Based on the calibrated system, the object under the line laser is measured, and the results of lines are assembled to make the final surface reconstruction. The results show that the designed system can reconstruct a region of 20×40 mm2, up to the accuracy of micron order.

Online measurement system of slab front-end bending in hot rough rolling based on line structured light vision

“…Li et al [17] presented a 3D simulation system of divergent multi-line laser projection based on the research of stripe projection measurement technology, which can simulate the 3D measurement system of divergent multi-line laser projection under computer environment. Yao and Liu [18] designed a telecentric surface reconstruction system for surface detection using a single camera with a telecentric lens, line laser generator and one-dimensional displacement platform, which can reconstruct the surface with high accuracy. Zhang [19] overviewed the primary state-of-the-art 3D shape measurement techniques based on structured light methods, especially those that could achieve high measurement speed and accuracy.…”

Assessment of out‐of‐plane structural defects using parallel laser line scanning system

“…Over the years, the laser triangulation technique has been extensively studied and applied to various areas in measuring the 3D contours of complex surfaces. In order to fulfill an entire 3D surface scan, the laser plane is required to move relative to the object with the help of accessory motion infrastructure, such as the stepper motor (Liang & Gu, 2020), robot arms (Idrobo-Pizo et al, 2019;Pavlovcic et al, 2021), and rotation and translation motion platform (Yao & Liu, 2021). The controllable relative motion of surface scanning is typically achieved by calibrating the motion accessories.…”

Detection of Bubble Defects on Tire Surface Based on Line Laser and Machine Vision

“…Using curvelet transform and the Canny edge detection method, studies [1][2][3] have accurately detected foreign bodies and bubbles inside the tire by studying the texture characteristics of defects. In the aspect of tire bubble detection, the line laser is rarely used, but it is still widely used in three-dimensional scanning [4][5][6][7][8][9][10][11], obtaining distance…”