Real-Time Nonlinear Tracking Control of Photopolymerization for Additive Manufacturing

In the context of additive manufacturing (AM) and 3D Printing, vat photopolymerization is an established technique in which photopolymer is selectively solidified to form a near-net-shape part. Photopolymerization-based AM is increasingly being adopted by the high-tech industry, but the technology still faces several challenges in terms of consistency in product quality, understanding of the UV curing process, in-situ process monitoring, and real-time closed-loop control. This paper aims to demonstrate the potential of model-based control of the UV curing process. The curing process is modelled and anticipatively controlled with an optimal control law for nonlinear systems, derived via a sequential linearization strategy. The potential of this approach is proven by means of both simulations that illustrate a one-dimensional spatial optimal tracking problem and experiments that validate a zero-dimensional controlled system.