Using Projected Light for Mobile Remote Guidance

A worker performing a physical task may need to ask for advice and guidance from an expert. This can be a problem if the expert is in some distant location. In this paper, we describe a system which allows the expert to see the workplace from the worker's point of view, and to draw annotations directly into that workplace using a pico-projector. Since the system can be worn by the worker, these projected annotations may move with the worker's movements. We describe a method for sticking these annotations to the original positions thereby compensating for the movement of the worker. We call this `StickyLight'. We conducted a user study to evaluate the performance and user preference for the system in `sticky' and freehand (`non-sticky') modes. We also compared the system on two platforms: helmet mounted and tripod mounted. Results indicate that freehand conditions took less time than sticky, and that tripod conditions took less time than helmet. However, participants reported preferences for sticky over non-sticky, likely due to the relative discomfort of keeping the helmet steady. This echoes the findings of several recent similar investigations..