Mrera (minimum Range Error Algorithm): Rfid - Gnss Integration for Vehicle Navigation in Urban Canyons

A new GPS positioning algorithm for vehicle tracking namely the “Minimum Range Error Algorithm” (MRERA) was proposed by E. Mok and L. Lam, to track vehicles in dense high-rise environments without the use of dead reckoning, and it can also be used for general geolocation positioning applications. With this algorithm, it is possible to identify which section of road network the mobile user is located, even when insufficient number of satellites are available for position fixing. This algorithm combines psuedorange measurements and coordinate information available in digital maps, used to identify which road section the GPS receiver falls into. Radio beacons should be available at regular intervals along the road network to transmit coodinate information for the MRERA processing engine to be able to compute the true range between the road point position and the available satellites. This paper discusses the integration of the emerging Radio Frequency Identification Technology (RFID) into the MRERA. Different RFID tags are now availabe on the market and a selection of RFID’s have been tested for the suitabilty of integrating into the MRERA. Particularly the type of RFID tags able to carry out long range commuincations under high dynamic conditions is suitable for this task. Such long range active RFID tags can be located along the road network and readers will be installed in the vehicles. Tests reported in the literature have shown that the tags information (e.g. the coordinates of its loctaion) can be read with vehicle speeds up to 150 km/h. If an insufficent number of satellites in GNSS positioning is detected the integrated RFID MRERA will be activated to estimate the vehicle’s position. The RFID approach compared to other radio transmission devices will be discussed.