Density Based Traffic Light Timing Control System

At the present time, the traffic control system becomes the main issue because of the fast increase in automobiles and also due to large time delays between traffic lights. So, in order to overcome this problem, we will go for density based traffic light timing control system. This article discusses how to control the traffic based on density.The proposed system uses IR sensors to calculate the traffic density. We have to place one IR sensor on every road; where the sensor always senses the traffic on that specific road. All these sensors are interfaced to the microcontroller. Based on the sensors, microcontroller detects the traffic and controls the traffic system.

Density Based Traffic Control System for Light Timing

The aim of the traffic control system project is to solve traffic congestion, To solve the problem, we have designed a framework for a dynamic and automatic traffic light control system and developed a simulation model with codes to help to build the system on hardware.

It is possible to propose dynamic time-based coordination schemes where the green signal time of the traffic lights is assigned based on the present conditions of traffic. This is achieved by using 3 pairs of IR sensors (Transmitter and Receiver) across the road to monitor a particular length/zone while vehicles on the same zone block the IR light falling on the IR receiver to assume low traffic density.

As there are 3 zones only, it is immaterial if vehicles are parked side by side. As it crosses the zone, the green time automatically changes as programmed

Hardware  Components

The hardware  requirements of this traffic control system project includes Power supply block, PIC microcontroller (pic16f877a), IR led, Photodiode, BC547, Led, 1N4007, Resistors, and Capacitors

Density Based Traffic Light Timing Control Block Diagram

PIC (PIC16F877A) Microcontroller

• High-Performance RISC CPU:
• Only 35 single-word instructions. All single-cycle instructions
• except for program branches, which are two cycles. Operating
• speed: DC – 20 MHz clock input DC – 200 ns instruction
• cycle Up to 8K x 14 words of Flash Program Memory, Up to
• 368 x 8 bytes of Data Memory (RAM), Up to 256 x 8 bytes of EEPROM Data Memory.
• Pinout compatible with other 28-pin or 40/44-pin, PIC16CXXX and PIC16FXXX microcontrollers.

PIC (PIC16F877A) Microcontroller

Special Features

• 100,000 erase/write cycle Enhanced Flash program memory typical.
• 1,000,000 erase/write cycle Data EEPROM memory typical.
• Data EEPROM Retention > 40 years.
• Self-reprogrammable under software control.
• In-Circuit Serial Programming™ (ICSP™) via two pins.
• Single-supply 5V In-Circuit Serial Programming.
• Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable operation.
• Programmable code protection. Power saving Sleep mode.
• Selectable oscillator options. In-Circuit Debug (ICD) via two pins.

IR LED

• An IR LED, also known as IR transmitter, is a special purpose LED that transmits infrared rays in the range of 760 nm wavelength.
• Such LEDs are usually made of gallium arsenide or aluminum gallium arsenide.
• They, along with IR receivers, are commonly used as sensors.The appearance is same as a common LED.
• Since the human eye cannot see the infrared radiations, it is not possible for a person to identify whether the IR LED is working or not, unlike a common LED.
• To overcome this problem, the camera on a cell phone can be used. The camera can show us the IR rays being emanated from the IR LED in a circuit.

IR LED

Photo Diode

• A photodiode is a type of photodetector capable of converting light into either current or voltage, depending upon the mode of operation.
• Photodiodes are similar to regular semiconductor diodes except that they may be either exposed (to detect vacuum UV or X-rays) or packaged with a window or optical fiber connection to allow light to reach the sensitive part of the device.

PhotoDiode

BC547

• The BC547 transistor is an NPN Epitaxial Silicon Transistor.
• The BC547 transistor is a general-purpose transistor in small plastic packages.
• It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA NPN general-purpose transistors.
• Whenever base is high, then current starts flowing through base and emitter and after that only current will pass from collector to emitter.

BC547

Working of  Project

The traffic control system project is intended to design a density-based dynamic traffic signal system. The timing of the signal changes routinely on detecting the density of traffic at the junction. Traffic jamming is a strict problem in several major cities across the world and it has become terrible for the commuters in these cities.

Conventional traffic light system is based on set time idea selected to each side of the junction which cannot be changed as per changeable traffic density. Junction timings selected are fixed. Sometimes high traffic density at one side of the junction demands longer green time as evaluated in typical allotted time.

Density Based Traffic Light Timing Control

The proposed system using an 8051 family microcontroller is interfaced duly with sensors, changes the timing of junction routinely to accommodate movement of vehicles smoothly avoiding unnecessary waiting time at the junction.

The sensors used in this project are IR and photodiodes are in a line of sight configuration across the loads to detect the density of the traffic signal. The density of the vehicles is measured in three zones (low, medium, and high) based on which timings are selected accordingly.

Further, this traffic control system can be enhanced by synchronizing all the traffic junctions in the city by founding an n/w among them. The n/w can be wired (or) wireless. This synchronization will very much helpful in reducing traffic congestion.

Therefore, from the above theory finally, we can conclude that using this project we can save a significant amount of time and also we can stop unnecessary traffic jams.Presently in India, we are following time-based control of traffic signals. We hope that this method will be adopted as soon as possible so that the problems we are facing with present method can be solved.Here is a question for you, what is the function of IR sensor?