# Video Interpolation-Based Multi-Source Data Fusion Method for Laser Processing Melt Pool
## 2 Experiments and Data Preprocessing  
### Laser Cladding Experimental Platform and Experimental Design  
The laser cladding experimental platform, as shown in Figure 1, consists of a laser cladding system and a multi-source data acquisition system. The laser cladding system includes a laser cladding head, a continuous 1080 nm laser with a maximum power of 2000 W, and a computer, with the cladding laser head mounted on a robotic arm that controls its motion. The multi-source data acquisition system is composed of a coaxial visible-light monitoring module and an off-axis temperature monitoring module connected to the laser cladding head via a beam-combination mirror.  
The coaxial visible-light monitoring module includes a beam-combination mirror, an 808 nm filter, a high-speed camera, and an auxiliary light source. The high-speed camera (Reevaler M230, Hefei, China) is coaxially connected to the filter and is introduced into the laser beam path through a 45\({}^{\circ}\) inclined beam combiner. This camera has a maximum frame rate of 25,000 FPS, a minimum exposure time of 1 \(\upmu\)s, and a maximum resolution of 1920 \(\times\) 1080. Equipped with an 808 nm laser as an auxiliary light source, during processing, the auxiliary light illuminates the processing area, reflects off the cladding head, and is projected onto the beam combiner by a focusing lens, reflected into the monitoring module by the beam combiner, and imaged by the high-speed camera. To ensure clear imaging of the melt pool and defects, the spatial resolution of the high-speed camera used in this study was 50 \(\upmu\)m/pixel, with an optical distance of 503 mm, a field of view (FOV) of 96 mm \(\times\) 54 mm, and a field-of-view angle of 12.5\({}^{\circ}\). In the experiment, the high-speed camera collected visible-light data at a resolution of 1920 \(\times\) 1080 and a frame rate of 100 FPS.  
Figure 1: Schematic diagram of the laser cladding experimental platform and experimental design.  
The off-axis temperature monitoring module is equipped with an infrared thermal camera (FLIR A615, Wilsonville, OR, USA) for capturing the temperature distribution in the melt pool area. The infrared thermal camera has a resolution of 640 \(\times\) 480 and a frame rate of 50 FPS and is installed at a 45\({}^{\circ}\) angle to the \(Z\)-axis. To ensure the accuracy of monitoring, the infrared thermal camera should be positioned as close to the processing area as possible. At a working distance of 600 mm, the infrared thermal camera has an FOV of 128 mm \(\times\) 96 mm, a field-of-view angle of 15.2\({}^{\circ}\), and a spatial resolution of 200 \(\upmu\)m/pixel. In the experiment, the infrared thermal camera collects infrared temperature distribution data at a resolution of 640 \(\times\) 480 and a frame rate of 50 FPS.  
In this experiment, a non-magnetic iron-based powder was selected as the material. The laser power was set to 1100 W, the laser spot diameter was 2.3 mm, the scanning speed was 9 mm/s, and the purity of the argon gas used reached 99.99%. The melt track was L-shaped, with the design details shown in Figure 1 within the blue dashed-line box. After adjusting the focal length of the two cameras, the visible-light data of the melt pool and the temperature distribution during the laser cladding process were recorded synchronously. A total of 694 visible-light images and 347 infrared temperature distribution images were collected in the experiment.