METHOD FOR MELT POOL MONITORING USING GREEN'S THEOREM

A method of controlling an additive manufacturing process in which a directed energy source is used to selectively melt material to form a workpiece, forming a melt pool in the process of melting. The method includes: using an imaging apparatus to generate an image of the melt pool comprising an array of individual image elements, the image including a measurement of at least one physical property for each of the individual image elements; from the measurements, mapping a melt pool boundary of the melt pool; applying Green's theorem to the melt pool boundary; and controlling at least one aspect of the additive manufacturing process with reference to the Green's theorem application.