Stabilization of standoff distance by efficient and adaptive updating of layer height command in directed energy deposition

Abstract

In directed energy deposition, the layer height command must match the actual clad height to maintain the standoff distance as constant between a deposition nozzle and workpiece. In this paper, an in-process layer-height-command updating method based on the on-machine measurement of the workpiece height is proposed. Our proposed method minimizes the required number of measurements to enhance process efficiency while maintaining the standoff distance fluctuation within tolerance. Additionally, the measurement interval is systematically determined by considering the tolerance and estimated difference between the layer height command and actual clad height, and the validity of the method was experimentally demonstrated.