Development of a New Laser-Based, Optical Indoor Positioning System

Abstract

This paper presents a novel optical indoor positioning system that is currently under development at the Institute of Geodesyand Photogrammetryat the ETH Zurich. The aim of theproject is to develop an automatic, inexpensive method capable of providing continuous sub-mm positions in real-time from a mobile device in all indoor environments. The system architecture does not require cost-intensivehigh-precision mechanics or sophisticated set-ups. The main purpose of the system called CLIPS (Camera and Laser based Indoor Positioning System) is the precise pose determination of a mobilecamera. The difference to the photogrammetric relative camera orientation is that it is based on the principle of an inverse camera, where one camera is substituted for a device that emitslaser-beams from a virtual central point.The laser beams project bright spots on any surface in an indoor environment. These laser spots are seen by a camera for the determination of its relative orientation with respect to the laser-device. First experiments have shown that the relative orientation of the camera could be correctly determined in all cases and that thenew system hasthe potential to achieve mm-level accuracy or better. However, the overall system performance has been limited so far due to an imprecise determination of the system-scale.