Dynamic control for LMD processes using sensor fusion and edge computing

Abstract

The quality of an LMD manufactured object highly depends on different process parameters such as the speed of powder deposition, the applied laser power, the powder feed rate, and other physical parameters such as the substrate temperature, resulting in a complex process. Consequently, applying corrections to the process parameters can be critical to improving the properties of the manufactured part. Some control approaches rely on open-loop techniques that use physical models and expert knowledge to adjust the tool path program in advance to compensate for deviations from the theoretical 3D model. Other approaches apply closed-loop control techniques to either control the melt pool during the process or adjust the tool path between layer depositions. This work presents a closed-loop control algorithm that dynamically controls three critical process parameters: the melt pool size, deposition speed, and standoff distance, combining data from a laser line profiler and a high-speed infrared camera.