Abstract
The objective of this work is the investigation of a new measurement system
for automatic recognition of the drive direction and position of moving vehicles. The centre of
activity was the development of a self-controlled automotive component which is able to read
passive magnetic barcode applied in the road surface. Of prime importance is the
independence of the recognition method from external systems (like GPS, induction meander
or light barrier), the simplicity of the data processing and the application of minimum amount
of instrumentation. The signal data, collected by a fluxgate sensor, is transferred to a special
ECU and is analyzed by a new method, called zoom-and-grid. The zoom-and-grid method
outputs digital values corresponding to the definition of the magnetic barcode (i.e. "right",
"wrong") or some positioning value (i.e. "P14"), which will be applied in the road surface.
These values can be used for visualization, for triggering of electronic signals or they can be
wirelessly transferred to a host traffic regulation system. The transfer of the output data can
be accomplished via existing wireless infrastructure like GSM/GPRS/UMTS or in a more
dedicated way with shorter reaction times via specific wireless roadside telematic networks
(e.g. combined with Car2Car communication) providing seamless connection to (fiber-
optical-based) broadband access. In the near future strong efforts will be put on Low-Power
Wireless Sensor Networks, enabling ad-hoc communication, fast handover between access
points and flexible topologies for redundant and secure data transmission with very little
delay times.
The car position acquired by the proposed method will be an essential input-value for any
control measures triggered by a monitoring center of infrastructure authorities. On-line
processing of actual car position data transmitted via high speed network infrastructure will
enable to calculate traffic parameters like speed, drive direction, traffic density or crash
scenarios and thus will contribute traffic safety.
The stability and functionality of the zoom-and-grid method were simulated and strenuously
tested in a laboratory, on a proving ground and under real conditions in the city and on the
highway. The evaluation of over 4200 data sets has shown that the zoom-and-grid method
works solidly and reliably. The main advantage of the system is that it is an independent part
of vehicle's electronics with an own local intelligence and it can be applied in highways,
cities, parking places or production halls.
Keywords - assistance, measurement, wireless, signal-processing, safety