08-16-2017, 10:07 PM
Real-time locating systems (RTLS)
Real-time locating systems (RTLS) is used to track and identify the location of objects in real time using nodes (badges/tags) attached to or embedded in objects and devices (readers) that receive the wireless signals from these tags to determine their locations.it is a system of finding the position of assets using active RFID tags. The tags broadcast a signal, which is received by three reader antennas. The time each signal is received is passed on to a software system that uses triangulation to calculate the location of the asset.
Types of technologies used:
Many embodiments use different technologies like:
-Active Radio Frequency Identification
-Infrared (IR)
-Active Radio Frequency Identification - Infrared Hybrid (Active RFID-IR)
-Optical Locating
-Ultrasound Identification
-Low-frequency Signpost Identification
-Bluetooth etc.
Wi-Fi-based Active RFID Tags are small, battery-powered wireless devices for locating and tracking any asset or person. Tag combines a streamlined flat form factor with long battery life, two call buttons, motion and temperature detection and tamper-proofing.An optional Exciter triggers tags as they pass through a choke point to transmit a message that is received by a standard Wi-Fi . Optional Location Receiver extends theVisibility System to outdoor and difficult environments. standard wireless networks from multiple leading networking vendors is used for communications, keeping the infrastructure cost low and enabling enterprises to gain more benefit from their existing WLAN.
http://theregister.co.uk/2007/08/21/aero...stems.html
Methodologies:
Physical methodologies used in real-time locating systems include:
-Angle of Arrival (AoA)
-Line-of-sight (LoS)
-Time Difference of Arrival (TDoA)
-Time of Arrival (ToA)
-Time of Flight (ToF) etc.
Locating at choke points:
It just communicates at coincidence of transceiver and transponder and is the only option to apply RFID tags for locating.
Locating in relative coordinates:
errors in locating:
-None or no direct response:
Sometimes the RTLS systems require direct and clear wireless visibility. Whenthere is no visibility, there will be no result or a non valid result from locating engine.
-False location:
The measured location may appear entirely faulty as a result of simple operational models to compensate for the plurality of error sources.
-Temporary location error:
Location will never be reported exactly, as real-time and precision cannot occur simultaneously.
Steady location error:
Caused by insufficient concepts to compensate for calibration needs
for details:
http://en.wikipediawiki/Real-time_locati...erminology