A closed loop welding controller for a rapid manufacturing process

The aim of this paper is to investigate on the closed loop welding controller of a rapid manufacturing shaped metal deposition (SMD) process. SMD was developed and patented by Rolls-Royce in order to produce mechanical parts directly from a CAD model. The paper describes a deep investigation upon the welding dynamics and parameters in order to develop an SMD automatic controller. An SMD plant has been set up as described in the paper, and some experimental work pieces have been produced. On the basis of the experiences acquired, some basic control laws have been carried out, and a closed loop controller has been implemented, using image processing and a video feedback control. The experimental results reported confirm the validity of the proposed strategy.