Hybrid ultrasound-RFID indoor positioning: Combining the best of both worlds

Abstract

Abstract-Existing hybrid ultrasound/RF positioning systems usually measure ultrasonic time-of-flight. This operation requires a wide bandwidth and this makes it rather noise sensitive, limiting the useful range. Therefore a new system is proposed where only the room-indicating capability of ultrasound is utilized and combined with RF. A portable tag obtains the room location by receiving a narrow bandwidth signal from a stationary ultrasound transmitter. The result is then relayed back over RF. This combines the high accuracy of ultrasound to pinpoint exactly the room location with the high communications capacity of RF that enables tracking of hundreds of simultaneously moving tags. Secondary parameters that may aid in refining the position such as ultrasound signal level and velocity may also be measured. In addition to the increased capacity, the use of portable receivers instead of transmitters, as in ultrasound-alone indoor positioning systems, also has the advantage of reduced user exposure to ultrasound due to the larger distance to the transmitters.

Impulse Radio Ultra-Wideband Communications for Localization and Tracking of Human Body and Limbs Movement for Healthcare Applications

“…For BS4, most of the antennas locations are in NLOS with the receiver, hence low Kurtosis index values (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) are observed. Highest values are observed for antennas placed on the wrist with respect to BS1 during sideways movements.…”

“…Infrared (IR) signals are low power and inexpensive but they cannot penetrate through obstructions. The systems based on ultrasound technology are relatively cheap; however they have lower precision in comparison with IR systems and are suitable for short range only [5][6][7][8]. A problem with inertial sensors such as accelerometers is that they suffer from a fluctuating offset and complex calibration procedure [9] while optical-based motion capture systems provide high accuracy but are expensive, require long calibration procedures, suffer from occlusions and are mostly confined to lab based measurements.…”

Experimental test system for distance estimation of standardized passive UHF RFID systems

“…A number of different systems for RFID localization have been proposed by various authors. However, unlike the presented approach they either use active tags [2], or require special tags as, they use techniques like surface acoustic waves [3] or hybrid ultrasound-RFID tags [4]. Contrary to this, the goal of the proposed system is to utilize standard RFID hardware.…”

Use of Graph Databases in Tourist Navigation Application

“…In Landmark-based positioning, positions of user are sensed or calculated respect to landmarks. Relative position of users' devices can be sensed using ultrasound (Holm, 2009), dead-reckoning (Etienne and Séguinot, 1993), collaborative positioning techniques (Lee et al, 2012) or inertial sensors (Vepa, 2011) mostly. Since landmarks can be detected and labeled indoors and outdoors, both, (see figure 1) it is possible to have positions of users seamlessly (Millonig and Schechtner, 2005).…”