Gps+ Rfid

摘要

Most of the developed systems for pedestrian navigation, and guidance services rely on GNSS, sometimes in combination with other sensors and positioning methods. Our approach in the Ubiquitous Cartography for Pedestrian Navigation (UCPNAVI) project uses active radio-frequency identification (RFID) in combination with GNSS and inertial navigation systems (INS) to navigate areas such as urban canyons and indoors, where satellite positioning does not fulfill pedestrian requirements. RFID transmits data via radio waves without line-of-sight contact. Nowadays, RFID can also be used for positioning, because the location estimation can be based on received signal strength indication (RSSI), which measures the power present in a received radio signal. The receiver can compute its position using various methods based on RSSI (for example, a range-based positioning system based on trilateration, modeling of indoor positioning systems based on location fingerprinting). We have employed three different methods in our research: cell-based positioning, trilateration using ranges to the surrounding RFID tags deduced from received signal-strength measurements, and RFID location fingerprinting. In our experiment for the positioning of a pedestrian from the subway station Karlsplatz to one of the offices in a building of the Vienna University of Technology, we combined all three methods.