Augmented vision and interactive monitoring in 3D printing process

This paper describes the beneficial impact of an augmented reality based technique on the 3D printing process monitoring within additive manufacturing machines. A marker is applied in a fixed point of the rapid prototyping machine, integral with the component being manufactured; as an alternative, a markerless approach can be followed too. A virtual model of the object to be printed is superimposed to the real one. In this way, the shape of the object in different printing stages can be viewed. An interactive comparison between real and virtual model can be carried out both in manual and automatic mode. If manufacturing errors are detected, the building process can be stopped. Augmented reality technique allows an intuitive shape check of a part being printed with rapid prototyping technologies. In case of complex objects it helps the operator in the detection of possible errors along the manufacturing process; stopping the machine as soon as an error appears avoids waste of machining time and material. The average precision of the augmented reality is useful to find significant geometrical errors; geometrical deviations less than 1 mm can hardly be assessed both in manual and in automatic mode, and further studies should be carried out to increase the technique precision and range of application. To the best of the authors' knowledge it is the first time where experiments on the integration between augmented reality and rapid prototyping to interactively monitor 3D parts' printing have been investigated and reported in literature.