Design and Characterization of a Portable Ultrasonic Indoor 3-D Positioning System

In this paper, an ultrasonic positioning system is presented and characterized, based on the usage of a portable grid of beacons and of a few fixed anchors. Since the beacon grid can be moved to guarantee line-of-sight transmissions, the proposed strategy is potentially suitable for accurate positioning of a mobile object in an environment with a complex geometry. The system was tested experimentally, exhibiting a subcentimeter positioning accuracy in a range up to 4 m.