Melt pool monitoring system and method for detecting errors in a multi-laser additive manufacturing process

An additive manufacturing machine comprising:

• a powder depositing system for depositing a layer of additive material onto a powder bed of the additive manufacturing machine;
• a first energy source for selectively directing a first energy beam onto a first focal point on the layer of additive material;
• a second energy source for simultaneously selectively directing a second energy beam onto a second focal point on the layer of additive material;
• a melt pool monitoring system for measuring electromagnetic energy emitted from the powder bed;
• and
• a controller operably coupled to the melt pool monitoring system, the controller being configured for:
• measuring first emission signals emitted from a first melt pool formed at the first focal point by the first energy beam;
• measuring second emission signals emitted from a second melt pool formed at the second focal point by the second energy beam;
• modifying the first emission signals based at least in part on the second emission signals to obtain a compensated emission signal;
• identifying outlier emissions where the compensated emission signal exceeds a predetermined signal threshold;
• and
• generating an alert in response to identifying outlier emissions;
• wherein modifying the first emission signals comprises modifying the first emission signals based at least in part on interactions between the first emission signals and the second emission signals, wherein the second emission signals are emitted from the powder bed at the second focal point.