Extrinsic calibration method for 3D scanning system with four coplanar laser profilers

Abstract

3D scanning is a crucial step to ensure the machining quality of the workpiece and is an essential part of intelligent manufacturing. However, existing scanning systems usually have only one profiler, which must be combined with a dynamic tracking system to achieve a complete scan of a workpiece. This scanning method has low efficiency and complicated path planning for ring-shaped workpieces. Therefore, in this article, an efficient and high-accuracy 3D scanning system is built, which is composed of a linear translation stage and four uniformly distributed laser profilers, and its extrinsic calibration method is studied. At first, based on the working parameters and spatial layout of multiple profilers, a stereoscopic calibrator composed of three non-collinear target balls (TBs) is designed. Then, a multi-profiler data fusion method is proposed, which utilizes a linear encoder to trigger the four profilers synchronously. Finally, by simultaneously using all data from the multiple profilers and the spherical constraint of each TB, all extrinsic parameters are accurately calibrated at the same time. Experimental results show that the average probing size error of the TB with a 38.1mm diameter is stable at about 0.007mm, and its extended uncertainty is about 0.100mm (k=2). In addition, standard cylinders and bend tubes are scanned, the results show that the proposed method can meet the high-accuracy calibration requirements of the tube bending deformation detection system.

Extrinsic Calibration for a Modular 3D Scanning Quality Validation Platform with a 3D Checkerboard

“…Legend: Multicapture (MC), single capture (SC), multitarget (MT), journal (J), conference (C), online (O), no explicit information (X), and not applicable (n.a.). Author and Reference Sensor Type Checkerboard or Scene Features Multicapture or Single Capture Publication Type Texture Required Autonomous Driving M. Lindner [ 37 ] PMD ToF–RGB camera (mono) 2D checkerboard Plane MC C Yes X S. Fuchs [ 38 ] ToF 2D checkerboard Plane (dark–bright) MC C Yes X J. Zhu [ 39 ] ToF–passive stereo 2D checkerboard Plane (dark–bright) MC C Yes X H. Zou [ 40 ] Laser profilers Spheres Spheres MC J No No J. Schmidt [ 41 …”

Procedure for the Orientation of Laser Triangulation Sensors to a Stereo Camera System for the Inline Measurement of Rubber Extrudate

“…They used a rectangular calibration object to calculate the orientation between the LTS coordinate system and the manufacturing coordinate system beforehand. Lafirenza et al (2023) and Zou et al (2023) used multiple spheres to create calibration objects to improve the quality of a point cloud based on LTS data or to orientate multiple LTS. These methods focus mainly on pure LTS data and do not consider additional sensors.…”

A calibration method for line-structured light using mirror-based virtual binocular vision system

“…Three-dimension measurement technique based on line laser has been widely used in practical industrial scenarios [1][2][3][4]. Accurate calibration results of camera parameters and light plane equation of line-structured light (LSL) are the vital basis for high precision 3D measurement [5]. Calibration methods for LSL can be divided into three categories: 1D target-based methods [6,7], 2D target-based methods [8][9][10][11] and 3D targetbased methods [12][13][14][15].…”