Development of an integrated inspection system for additive and subtractive hybrid manufacturing

Abstract

Using closed-loop inspection systems to modify coordinate metrology tasks for specific engineering applications has been a demanding research subject over the last decade. The objective of this thesis is to develop an Integrated Inspection System (IIS) that uses these tasks for applications in systems combining additive and subtractive manufacturing technologies, commonly referred to as hybrid manufacturing. Hybrid manufacturing has opened a new and innovative avenue in product development, and also in product repair and maintenance. One of the areas where it can excel is in the repair of dies and moulds. This is due to the ability to add material to worn out areas, then subtract the excess material to return to the ideal geometry without affecting a large area of the piece. Previously developed coordinate metrology techniques can be modified to aid in the minimization of the cost of repair. A method using skin modelling techniques and weighted total least squares was utilized to determine the geometry of the repaired zone. These methods were combined to create the developed system which minimizes the repair cost. The best result of this method was then used as an initial condition for an optimization algorithm resulting in the optimal solution. The developed system produced cost reductions in all tested circumstances, with the best results found in surfaces with large, non-uniform errors. The developed system can be implemented and customized for various hybrid manufacturing applications in the pursuit of lower repair costs.