Sarah Meyers :
Daimler AG Chooses VITRONIC for Weld-Seam Inspection Technology
Sarah Meyers :
Daimler AG becomes the first vehicle manufacturer to utilize a system for the automated inspection and optimization of welded seams. The overall concept developed by Daimler was implemented for the first time for rear axle carrier assembly on the new C-Class. Since installing VITRONIC´s weld seam inspection technology at Mettingen in February 2007, more than 8 million welded seams alone have been successfully inspected and, if required, optimized.
The goal of Daimler AG was to replace the existing manual welded seam inspection and reconditioning with an automated inspection and optimization system working in a line cycle. Based on a comparison of different sensor systems, the inspection system VIROwsi by VITRONIC was certified for use after extensive field tests, and customized according to Daimler´s user-specific needs. The inspection systems were calibrated during the launch of
rear axle carrier production for the new C-Class. The process capability of VIROwsi automated inspection and optimization has been persistently proven.
The rear axle carriers are manufactured on lines in several assembly stages, with each line operating exactly the same production methods. Components with a different number of seams are welded together in a welding booth, with the welded assembly being inspected automatically during the next stage of production. If necessary the components are optimized and inspected again.
The inspection takes place automatically in the inspection and optimization areas. The VIROwsi inspection system is based on the laser triangulation method. A semiconductor laser, housed in a compact sensor, projects a line on the welded seam while a high-speed camera, also housed in the sensor, captures the line as an elevation profile. A three-dimensional image of the welded seam surface is created gradually through the relative motion of the sensor and the object. All relevant deviation of the ideal welded joint could be identified with 100 per cent accuracy. Therefore, a broad range of defect types, which are available for further processing after the inspection procedure, were defined for the start of production.
VIRO Eliminates Manual Inspection/add one
An extensive proprietary software toolbox for inspection and optimization, which processes
the defect´s type and location information for the automatic optimization, was developed by the PWT/VUF department. Additionally, this toolbox also carries out the visualization and archiving of all inspection results. The burner for re-welding is also mounted next to the inspection sensor on the inspection/optimization robot. If a defect is detected by the inspection system, the software decides if and how the optimization process will be performed.
To complete the full documentation of each welded joint, the software also archives all inspection results. Each test result is stored in a designed database. The database contains all relevant information like the component number and the quality of each component (good/bad) in order to guarantee complete traceability. The production process can be optimized and visualized consequently.
For rapid system/welded seam optimization, all testing results can be represented in different ways. For example, the defect´s location is shown in color directly on the component for the machine operator. Additionally, tables/statistics with detailed information about several thicknesses are available in the system.
The automated and optical welded seam inspection process has been used for simpler inspection tasks in industrial production for years. As the first vehicle manufacturer, Daimler AG goes one step further and puts into practice an automated optimizing line cycle process. Daimler AG is also committed to this concept for future axle models. Additionally, the propagation of its use to other components is being looked into.
Headquartered in Germany, VITRONIC MACHINE VISION LTD. is an international manufacturer of three-dimensional scanning devices. The company specializes in supplying and developing cutting-edge scanning technologies for the logistics, manufacturing, science and warehousing industries. VIPAC, the corporation´s signature product, is a 3-D machine vision scanner that utilizes a compact, high-speed line-scan camera to provide high-resolution images of standard and oversized parcels. With a full complement of vision scanning product offerings with fully customizable solutions, the VITRONIC team handles 100% of the research, design, development and manufacture of their hardware and software applications. The privately-held company was founded in 1984 by Norbert Stein, Ph.D., and is represented on four continents.