Optical Seam Inspection

Interview conducted by G.P. ThomasOct 24 2012

Product manager at VITRONIC, Markus Maurer, talks to AZoM about the key advantages of automated camera-based optical seam inspection.

Could you please provide a brief overview of VITRONIC and the key sectors in which it operates?

Founded in 1984, VITRONIC today is a global market leader in industrial machine vision. The company with subsidiaries on four continents and a workforce of about 400 employees offers machine vision systems in three main areas: industrial automation, logistics and traffic technology. The product range spans from standardized to individually customized solutions. All products are developed and produced in-house by VITRONIC. Products are currently in use in 40 countries.

Since 1994 more than 200 of VITRONIC’s weld seam inspection systems have been installed and successfully deployed around the world at renowned companies in the automotive and automotive supply sectors.

VITRONIC recently published a white paper on advantages of optical seam inspection – could you provide an overview of this?

The automatic, camera based optical seam inspection delivers benefits to nearly every company where automatic welding or brazing is carried out for large unit volumes. The white paper points out how these inspection systems:

• test all relevant welding and brazing seams 100 percent reliably for quality,
• inspect steel, aluminium and other materials,
• reduce scrap parts as the result of early defect detection,
• replace expensive manual reworking with cost-effective, automative reworking of seams,
• send alerts automatically when defined warning thresholds are exceeded, thereby enabling the early correction of deviances in joining processes,
• document and archive product quality based on the inspection results as proof for the customer,
• offer statistical analysis as the foundation for process optimization and cost reduction,
• allow short term ROI,
• help achieve higher customer satisfaction, grant a competitive advantage and generate new business potential,
• improve welding quality in the long term through inspection stability.

Could you describe the main advantages of camera-based seam inspection systems over manual visual inspection?

In comparison to manual, subjective visual inspection by trained employees, an automated optical inspection system always works objectively, according to individual yet constant criteria, without any impact from external factors or the employee’s form of the day. Additionally, manual visual inspection requires a large human resources contingent. Automated optical seam inspection on the other hand allows to inspect cost efficiently with only one system that operates day and night at high quality standards – and this pays off for the company.

What industries is automated seam inspection suitable for?

Camera based inspection can especially be used by companies that have welding or brazing processes automated and produce large quantity. For example the automotive industry and automotive supply sectors deploy this kind of inspection systems and benefit enormously.

What costs are involved in automated welded seam inspection?

The costs of inspection solutions depend on the customer’s individual requirements. But generally high-quality inspection systems are an investment that pays off. Usually the ROI of the automated system compared to visual inspection performed by employees is less than one year. With the introduction of automated weld seam inspection employees currently used for manual inspection can be assigned to other tasks, the manual capture and documentation of the inspection results are automated and processes and reworking can be optimized.

Are there any limitations to 3D seam inspection?

Yes. If geometrical features are missing, combined 2D and 3D technology for seam inspection is required. This makes it possible to perform seam inspection even if the geometric characteristics – such as seams without surface profile – are not available and the existence of a seam and its position has to be verified. By using the combination of 2D and 3D machine vision, the contrasts that arise due to discoloration or visible structural changes at the weld can be detected automatically.

How safe is this inspection process?

It is very safe and unfailing. Automatic, camera based inspection always works objectively, reliably and, if needed, 24/7 – completely fatigue-free. Additionally, the uninterrupted documentation of all inspection results can be visually displayed at all times and a warning alert helps to quickly localize and correct defects before increased scrap is generated. The relevant parameters are defined according to the individual production and quality requirements. All generated data is included in the statistics which can be used to systematically improve product quality.

How can weld seam inspection systems be integrated into industry?

The inspection systems can be integrated into new as well as into existing production facilities. Of course the easiest way is to start from scratch. This way all relevant factors can be taken into consideration, such as space limits of the facility, the ideal position for the inspection system, the reworking concept etc. In either case, various options are available – from the sensor being fixed-mounted to it being mounted on a robot. Which solution suits best, depends on the customer’s individual requirements.

Lastly, where can people find more information about this white paper?

The white paper can be requested at http://www.vitronic.de/en/seaminspection/ or by sending an e-mail to [email protected]