Developing a sophisticated traffic monitoring and
control system would result in an effective solution to this problem. In a
conventional traffic light controller, the traffic lights change at constant
cycle time. Hence it does not provide an optimal solution. Many traffic light
controllers implemented in current practice, are based on the 'time-of-the-day'
scheme, which use a limited number of predetermined traffic light patterns and
implement these patterns depending upon the time of the day. These automated
systems do not provide an optimal control for fluctuating traffic volumes.
A traffic
light controller based on fuzzy logic can be used for optimum control of
fluctuating traffic volumes such as over saturated or unusual load conditions.
The objective is to improve the vehicular throughput and minimize delays. The
rules of fuzzy logic controller are formulated by following the same protocols
that a human operator would use to control the time intervals of the traffic
light. The length of the current green phase is extended or terminated
depending upon the 'arrival' i.e. the number of vehicles approaching the green
phase and the 'queue' that corresponds to the number of queuing vehicles in red
phases. A prototype system for controlling traffic at an intersection is
designed using Simulink and Matlab tool. The decision on the duration of the
extension is taken using the Matlab tool. This decision is based on the Arrival
and Queue of vehicles, which is imported in Matlab from VB6 environment. The
time delay experienced by the vehicles using the fixed as well as fuzzy traffic
controller is then compared to observe the effectiveness of the fuzzy traffic
controller.
Here we make use of a matlab based system to find
the volume of vehicles in each side of a junction. The images to be processed
are collected from a Wireless camera mounted above the traffic light control
unit. These images are sent to a matlab based system, where they are iterated
towards some pre stored images in the data base to analyze the traffic volume.
After reaching a conclusion, the predicted
information regarding the volume are sent to an embedded unit wirelessly. We
make use of a protocol named ZIGBEE, an advance version of Bluetooth to
transmit this information to the embedded unit
ZigBee is a wireless technology
developed as an open global standard to address the unique needs of low-cost,
low-power, wireless sensor networks. The standard takes full advantage of
the IEEE 802.15.4 physical radio specification and operates in unlicensed bands
worldwide. The specification is a packet-based radio protocol that meets the
needs of low-cost, battery-operated devices. The protocol allows devices to
intercommunicate and be powered by batteries that last years instead of hours.
After receiving the
volume estimation from the PC, via Zigbee, the FPGA unit generates pulses, in
accordance with the information from MATLAB which determines the time duration
of traffic light.
In the normal
working, i.e. if the volume is regular in junctions, the controller
automatically generate uniform time signals for traffic light.
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