Towards Vision-based Closed-loop Additive Manufacturing: A Review

The use of additive manufacturing technology has grown considerably in the last decade. Starting from a futuristic idea, additive manufacturing has shown to be a great tool for rapid prototyping and has found its way into industry as a set of techniques for manufacturing highly customized parts. However, a great number of challenges remain if we are to have efficient and general additive manufacturing systems with high precision, low failure rates, and good strategies for detecting and dealing with part failures. In this paper, the current state-of-the-art on online monitoring and closed-loop control in fused filament fabrication and directed energy deposition with camera and laser scanning is presented. A discussion on the challenges and possible ways of enabling full online part geometry monitoring in AM with articulated manipulators and multi-axis deposition is also provided.