28 Sep 2007
Laser scanners that enable 3D inspection of car components could shave ten weeks off the time taken to roll out new automotive production lines.
Automotive manufacturers Volvo and laser-inspection developers Metris have assessed the impact of using optical 3D inspection methods to measure the dimensional accuracy of automotive components, and of subsequent virtual assembly of the scanned parts.
They found that using laser scanning instead of tactile probes to verify the components' 3D geometry during the vital pre-production development phase produced results more rapidly and in a form which was easier to interpret.
"The components that make up a vehicle must fit perfectly," said Alfons Van Den Bergh of Volvo. "Dimensionally-stable components ultimately determine the production quality level of a car."
After evaluating the scanners during start-up and production of the Volvo C30, performing traditional inspection methods in parallel to set benchmarks, the company believes the rollout of new car assembly processes could be shortened by up to ten weeks as a result.
The company employed a Metris XC50-LS laser scanner mounted on a coordinate-measurement machine for automated feature inspection. A K-Scan handheld laser scanner was used for mobile inspection tasks, including final quality control of the finished vehicles and checking that gaps between vehicle sections were within defined tolerances.
Results from the laser scanners were presented as 3D point cloud, a digital representation of the surface generated from the thousands of measurement points scanned per second. The point cloud can then be compared to the original CAD data, giving an error color chart that clearly clearly shows out-of-tolerance deviations in a readily understood manner.
The data allowed Volvo to assemble virtual vehicles by connecting geometry data with representations of other components, such as CAD models or other scanned parts, resulting in substantial time savings.
Van Den Bergh is convinced that deploying the new scanning methods will also facilitate easier inspection of incoming components from other suppliers and allow clearer communication between them. "Optical laser technologies will undoubtedly gain importance in combination with tactile inspection methods," he said.