Laser welding monitoring apparatus

A laser welding monitoring apparatus that monitors a state of processing with laser welding, the laser welding monitoring apparatus comprising:

• an acquisition interface that acquires a signal corresponding to measurement light measured by irradiating a workpiece with laser light;
• an arithmetic circuit that performs arithmetic processing of determining the state of processing based on the signal acquired by the acquisition interface;
• and
• a storage device that stores in advance variation tendency information corresponding to a tendency of intensity of the measurement light to vary depending on a position of a processing point in a region scannable with the laser light by using an optical system including a galvanometer mirror and a scan lens on the workpiece,
• wherein the measurement light includes plasma light generated at the processing point through irradiation with the laser light, heat radiation light, and reflected light of the laser light,
• the measurement light is received through the optical system when scanning is performed with the laser light by the optical system in a predetermined welding pattern, and is spectrally dispersed into the plasma light, the heat radiation light, and the reflected light,
• the acquisition interface acquires an intensity signal indicating intensity of each of the plasma light, the heat radiation light, and the reflected light after the measurement light is spectrally dispersed, and
• the arithmetic circuit:
• corrects the intensity signal and suppresses a variation in intensity depending on a position of the processing point based on the variation tendency information for each of the plasma light, the heat radiation light, and the reflected light;
• and
• determines the state of processing based on the intensity signal that has been corrected.