Optical coherence tomography for laser welding applications

In order to realize the automatic quality measurement of laser welding parts, an automatic on-line quality measurement system is established. The optical coherence tomography algorithm used in the system is studied. Firstly, the test equipment of laser welding quality inspection system is built based on optical coherence tomography algorithm. Then, the typical control algorithm is analyzed by taking the scanning galvanometer control as an example, that is, high-precision scanning and high-precision image acquisition in X and Y directions are realized. Then, the image is processed by dual-tree complex wavelet transform. Finally, the test sample is tested with the test equipment and the test results are analyzed. Experimental results show that this method can detect the quality of laser welding seam, and the detection accuracy is 5 µm. It provides industrial solutions for the online inspection of the laser welding to enable consistent and high quality welds.