A digital twin for manufacturing with direct energy deposition: a stellarator inner vessel case study

A digital twin of a direct energy deposition manufacturing cell has been employed to monitor the build of a stellarator inner vessel. This case study shows the suitability of direct energy deposition as a method for additive manufacturing of fusion relevant components and the utility in monitoring processing, processing data relating to the component along with providing a platform for future optimisation and subsequent machining steps. The integrated instrumentation includes a laser scanner along with cameras which captures the evolution of geometry during manufacturing. The data obtained can be used to identify faults during manufacturing prior to the parts completion. With the data stored in the digital twin there is scope to use the recorded true deposition geometry and the true robot motion for both path optimisations through machine learning and improved process understanding with modelling and co-simulation. The recorded final geometry is also ideal for specifying finishing steps such as machining.