On the influence of scanning factors on the laser scanner-based 3D inspection process

Abstract

3D inspection process is getting more and more interest for manufacturing industries as it helps to carefully check the expected quality of the released products. Much more attention is oriented to optical devices able to quickly capture the whole shape of the product providing many useful information on the process variability and the deliverability of the key characteristics linked to the quality of the product/process. Although the optical control of 3D scanners is mature enough, many factors may influence the quality of the scanned data. These factors may be strictly related to internal elements to the acquisition device, such as scanner resolution and accuracy, and external to it, such as proper selection of scanning parameters, ambient lighting and characteristics of the object surface being scanned (e.g. surface colour, glossiness, roughness, shape), as well as the sensor-to-surface relative position. For the 3D laser-based scanners, the most common on the market, it would be of great industrial interest to study some scanning factors mainly affecting the quality of the 3D surface acquisitions and provide users with guidelines in order to correctly set them so to increase the massive usage of these systems in the product inspection activities. In this context, by using a commercial triangulation 3D laser scanner, the effects of some scanning factors that may affect the measurement process were analysed in the present paper. Working on a sheet metal test part, more complex than the ones commonly used in laboratory and documented in the literature, the scanner-to-object relative orientation and the ambient lighting, as well as an internal scanner parameter, were tested. Through a Design of Experiments (DoE) approach, and setting root mean square error (RMSE) as response function, the outcomes of the tests mainly pointed out that the scanner-to-object relative orientation as well as its position within the field of view of the measurement device are the key factors mostly influencing the accuracy of the measurement process

Evaluation of Handheld Scanners for Automotive Applications

“…The Taguchi approach was used in the experimental design to determine the appropriate values for the scanning parameters to achieve the shortest scanning time and lowest error. To evaluate the effect of laser scanning parameters, as well as the object position and angle on the scanner accuracy, Gerbino et al (2016) [14] also employed design of experiment methodology. They used Geomagics software to evaluate the accuracy of scanning objects.…”

A New Interactive Railway Virtual Simulator for Testing Preventive Safety

“…The Immersive Augmented Reality is realized through a Head-Mounted Display (HMD) through which the user, protagonist of the experience of the driver, sees perfectly overlaid the configuration of the virtual command devices (CAD geometries) with the geometry of the physical dashboard in order to interact naturally in the immersive environment. The geometry of the dashboard was acquired through synthetic Reverse Engineering techniques from a real one [21], [22]. User interaction with the simulator takes place through the NUI (Natural User Interfaces) based on the markerless tracing of parts of the user's body.…”

Analysis of Modern Optical Inspection Systems for Parts Manufactured by Selective Laser Melting

“…Several studies have demonstrated the influence of these factors in the process of digitization and accuracy according to different non-contact systems. Gerbino et al [23] analyzed the influence of some scanning factors in the measurement process with a laser scanning (LS) sensor. In a previous work, we studied the accuracy of a structured blue-light (SL) sensor when measuring different form features under usual working conditions with different fields of view (FOVs) [24].…”