PHOENIX

PHOENIX

Process Control through the Fusion of Photonic and Acoustic Sensor Modalities for Laser-assisted Joining of Metal-plastic Hybrids, Supported by a Digital Expert System

Developed at Fraunhofer IWS, a control method for laser structuring based on acoustic process emissions (Steege et al., Advanced Engineering Materials, 2025, DOI: 10.1002/adem.202402505).
© Fraunhofer IWS
Developed at Fraunhofer IWS, a control method for laser structuring based on acoustic process emissions (Steege et al., Advanced Engineering Materials, 2025, DOI: 10.1002/adem.202402505).

Motivation 

Continuous-wave (cw) laser structuring is a key process step in thermal direct joining, yet it cannot currently be measured or controlled in situ with sufficient reliability. On the one hand, the structuring quality is significantly influenced by varying factors such as material composition, component geometry, surface condition, and the laser system technology used. On the other hand, existing single-sensor systems are unable to reliably capture essential structural parameters such as depth, flank angle, or undercuts. Therefore, the subproject “Multimodal Sensor Fusion and Real-Time Control for cw Laser Structuring Processes” aims to implement inline monitoring as well as adaptive process control.

Objective and Approach

Specifically, the research activities aim to detect and actively influence the structural parameters in real time through the fusion of photonic emission and acoustic signals. This ensures reproducible structure quality for industrial joining processes such as thermal direct joining, drastically reduces the extensive effort required for subsequent component inspection, and guarantees a low scrap rate.

Innovation und Perspectives

The project goes well beyond the current state of the art, as it will, for the first time, fuse acoustic and photonic sensor data in real time for process control and quality assurance in cw laser structuring. In the long term, this enables fully digitalized, adaptive, and cost-effective laser structuring for industrial series production.