Real-time implementation of generalized predictive algorithm for direct metal deposition (DMD) process control

摘要

A direct metal deposition (DMD) process is stabilized by monitoring the temperature and the shape of the melt pool during deposition, applying a recursive least square (RLS) model estimation algorithm to adaptively identify process characteristics in accordance with the temperature and the shape of the melt pool, and delivering the process characteristics to a generalized predictive controller with input constraints to control the process. The process may be controlled by adjusting laser power or by adjusting the speed of the movement of the laser. In the preferred embodiment the temperature is monitored using a two-color pyrometer, and the shape of the melt pool is monitored by detecting the edge of the melt pool with a camera and/or photodetector.

主权项

1. A method of stabilizing a direct metal deposition (DMD) process of the type wherein a powder is fed into a laser-generated melt pool, comprising the steps of:
monitoring the temperature and the shape of the melt pool during deposition of the melt pool; applying a recursive least square (RLS) model estimation algorithm to data generated by monitoring the temperature and the shape of the melt pool for identifying process characteristics from the temperature and the shape of the melt pool; delivering the process characteristics to a generalized predictive controller for predicting the temperature and shape of the melt pool and adjusting the process characteristics with input constraints from predicted temperature and shape of the melt pool to control the direct metal deposition process in real time.