Different pathways to proven quality: Multi-approach FOD detection technology

Author: Hazem Ali, Senior Automation Control Engineer  | Publish date 22.10.2025

Foreign Object Debris (FOD) remains a critical challenge in aerospace production, where even small contaminants can compromise structural integrity. While our systems, with encapsulated material processing environment including air filters, and the use of qualified quality material already minimize risk of FOD occurrence, in particular compared to manual processes, they cannot be ruled out completely. To address this topic, our team continues developing multiple detection methodologies, catering to different production environments and material types.

Within recent projects, we’ve adopted two proven approaches for SAMBA Series lay-up systems, confirming their applicability. Currently, we’re also advancing two additional, innovative methodologies. This ensures our customers benefit from both reliable, field-tested solutions as well as from advanced, new detection capabilities

Contrast-based detection: Simple yet powerful

Our first approach leverages the natural color contrast between foreign debris and the base material. Using advanced blob detection algorithms, the system identifies light-colored debris on dark carbon fiber patches – or vice versa. What makes this method particularly attractive is its simplicity: no additional hardware required, just our latest vision software working intelligently with the existing cameras of FPP lay-up systems.

This method proved highly effective for detecting light-colored fibers or release film fragments on black carbon patches. The system processes images in real-time, providing immediate pass/fail indicators on the production line. It also generally works for lighter colored material like glass fiber prepreg, only that some FOD produces lower contrast.

The system offers extensive configurability to adapt to different materials and production conditions. Operators can fine-tune detection sensitivity through adjustable parameters including minimum and maximum debris size thresholds, noise filter settings to eliminate false positives, and boundary exclusion zones that ignore edge artifacts while focusing on critical inspection areas. This flexibility ensures optimal performance across various fiber materials and colors.

Shadow-based geometry detection: Seeing shape, not color

Some debris hides in plain sight: their color blends seamlessly with the background material. For these challenging cases, we developed a shadow-based detection approach that reveals surface geometry through directional lighting.

The technique employs strategically positioned lights that illuminate the inspection area from different angles. As each light activates, it casts shadows that emphasize any elevated debris or surface irregularities. By combining these shadow patterns, the system creates a three-dimensional understanding of the surface. Any foreign debris – regardless of its color- creates distinctive shadow signatures.

Glass fiber presented unique challenges because traditional contrast methods struggled. With shadow-based geometry detection, we’re essentially mapping the topology of contamination, independent on color contrast.

Next-generation Optical Intelligence in FOD Detection

Among several innovations currently in advanced testing, two stand out for their impact on detection performance and reliability. The first leverages wave length-selective illumination to highlight subtle material contrasts that vision might not detect with standard lighting. By dynamically adjusting spectral conditions, the system can reveal contaminants that would otherwise blend into the background – effectively adding a new “dimension of vision” without compromising resolution.

The second enhancement focuses on intelligent motion analysis. By evaluating how potential debris behaves as material moves through the system, the technology distinguishes between real contaminants and transient reflections or lighting artifacts. This significantly reduces false positives while maintaining full sensitivity to genuine foreign objects.

Together, these developments move optical inspection closer to human-like perception – discerning what truly matters while ignoring what doesn’t.

Looking Forward

Cevotec’s development of multiple FOD detection technologies – both proven and emerging – ensures that FPP lay-up technology can be deployed meeting stringent FOD requirements. Aerospace composite manufacturers have access to effective solutions for their particular process and material combinations.