A fully inline-capable solution from Blackbird enables the contactless detection and classification of seam defects in real time – cycle time-neutral and without influencing the welding result.
The new ‘OCT Seam Inspection’ feature is an extension for inline quality assurance in the welding process. Based on optical coherence tomography (OCT), the seam geometry and surface defects are recorded without contact, in real time and without affecting process stability – even with high-frequency oscillation up to 1000 Hz. Seam inspection is therefore completely cycle time-neutral and can be integrated directly into production without any loss of cycle time.
At the heart of the seam inspection is a multi-stage evaluation model: individual OCT measurement lines are continuously recorded along the weld seam and the seam surface is automatically detected. Seam characteristics are calculated from this and checked for defined defect characteristics. Recurring or neighboring individual deviations are intelligently combined into collective defects – for example in the case of pores or holes. In addition, the overall quality of the seam is evaluated as a percentage in order to identify systematic defect distributions along the welding line. All limit values and minimum sizes can be configured individually for each defect type.
The solution currently supports the evaluation of fillet and lap seams at the lap joint. The underlying architecture is open and can be flexibly adapted to new geometries and customer-specific inspection requirements. It can also be combined with other OCT functions: edge tracking or weld-in depth monitoring, for example, can be activated and operated together within the same sensor setup.
Direct process connection and transparent data communication
During the process, the system supplies standardized OK/NOK signals and associated error classifications directly to the higher-level control system. If defined tolerances are exceeded, programmable reactions can take place automatically, such as stopping the welding program or ejecting faulty parts. At a later stage, all measurement data, evaluations and score values can be made available via standardized interfaces – such as OPC UA. This can be used for quality assurance, traceability or statistical evaluations, among other things.
OCT-supported seam inspection is designed for continuous industrial operation, is highly scalable and requires little maintenance. The system does not require any additional light sources and can be easily integrated into existing system concepts. Additional evaluation logics and seam types can be added via software updates without hardware changes – future-proof, expandable and efficient.
The functions are available from version 8.28 of the RSU user software.