Projector-based augmented reality with simultaneous 3D inspection using a single DMD

This paper presents an industrial augmented reality system that simultaneously measures a component, identifies possible defects and displays the inspection result directly on the component. The processing is done in real time using a single DMD-based projector for both the inspection and augmented reality. The use of a single DMD eliminates the issue of registration between the component being inspected and an auxiliary augmented reality projector. The use of a single projection system also eliminates possible occlusion due to parallax between both projection systems. The system uses an algorithm that computes at video frame rate the temporal sequences of micromirror positions that, when imaged by a high-speed camera, contains a set of structured-light patterns. The temporal sequences are designed such that a human observer sees the desired augmented information. The proposed prototype can acquire 12 range images per second. The range uncertainty at 1-σ is 14 μm and each range image contains approximately one million 3D points.