18-03-2011, 04:31 PM
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Vehicle Density based Traffic Signal Light
There has been a need to automatically control things from a distance depending on a certain timing logic. In recent past there had been many instances of accidents on the roads, at the crossings near the colonies for the fact that there were no streetlights ON in the night when the visibility of the driver is poor. Even at the junctions such as T-junction, Y-junctions or circle we should be able to distribute the traffic in such way that the traffic management should be balanced.
To overcome this problem we are designing a system, which can control the traffic according to the density of vehicles. A Micro-Controller and a Personal Computer in which all timing related details are fed to the PC and then the control signals are passed to a 89C51 based board which in-turn controls the various lights.
This project of ours features Bi-Directional flow of information from and to the Base Station. Sensors are connected to the Micro controller, which sends the information as to which path should be open. According to the vehicle density information corresponding signal lights should glow to pass the traffic. Thus vehicle density based traffic signal is indispensable for accurate services. Standing at the signal for long duration consumes more petrol and time. The aim of this project is to save time, save money and petrol and make the traffic management accurate.
The sensors used can be of the IR / LASER type for the Through Beam type sensor or Inductive type Metal sensors.
This project will also employ a remote control in the hands of the traffic policeman to override any of the signals being chosen by the PC by default. The Transmitters work on 433 MHz Carrier Frequency and our model will employ one set of Transmitter and Receivers, for the information transfer.
The front End will be made in Visual Basic and using the Serial or the Parallel port will establish the communication with the Micro-Controller. For Serial Port Communication we will use RS232 Protocol.
Block diagram of Vehicle Density Based Traffic Controller
In this diagram we are depicting that the Micro-Controller 89C51 is acting as the basic controlling module and the information t control the signals and the other things are being sent by the Visual Basic code running in the PC.
There are different types of sensors that will be employed, For example we will use Inductive type metal sensors/ LASER sensors, and other press type sensors/switches being depicted by three different blocks in the diagram. There will be a need of totally 12 sensors to put 3 on each side. The sensor status will be sent to the PC and the PC will then decide on what action needs to be taken.
The signals will be depicted by using LED’s (Red and Green) and will be controlled by the decision from the PC.
The PC will also initiate the process of the controlling the zonal lighting and in case the time of the PC matches the switching ON time of the lightings, they will be switched ON and vice versa.
The PC side of the RS232 communication part works on the RS232 protocol levels which are ±12V and on the micro-controller side it works on the TTL levels. To achieve this communication and voltage conversion we employ a MAX232 which is a UART Transceiver.
TLP434 and RLP434 are used for the Wireless controlling which will be in the remote of the traffic policeman to override the signals coming from the PC.
HT12D and HT12E are the decoders and the encoders which will be used to convert the parallel to serial data to enable transmission and serial to parallel on the reception side.
