Temperature determination in laser welding based upon a hyperspectral imaging technique

Hyperspectral imaging (HSI) is a very promising technique for temperature determination in laser welding without the need for a priori knowledge of the emissivity. HSI is commonly considered a technique that allows to simultaneously acquire spatial as well as spectral information - that is essentially containing the temperature information - upon the investigated object. For that purpose, we developed a suitable HSI-system comprising a self-designed HSI-lens system and a high-speed CMOS-camera. In the present paper we address influences upon the HSI-based temperature determination and present as well as discuss temperature determination results in laser welding of metal sheets. (C) 2019 Published by Elsevier Ltd on behalf of CIRP.