traffic light

1. On
Submitted by
Banzadio salazaku
Roll 2013010100016
B tech E and I
6th
sem
Submitted to
Mrs. Arti Nagpal

2. Preface
An industrial PLCs system is used for the development of the controls of
machinery. This paper describes the PLCs systems in terms of their
architecture, their interface to the process hardware, the functionality
and the application development facilities they provide. Some attention
is also paid to the industrial standards to which they abide their planned
evolution as well as the potential benefits of their use.
Ladder Logic is a graphical programming language, initially programmed
with simple contacts that simulates the opening and closing of relays.
Ladder Logic programming has been expanded to include functions such
as Counters, Timers, shift Registers and math operations.
Ladder logic is a method of drawing electrical logic schematics. It is now
a graphical language very popular for programming Programmable Logic
Controllers (PLCs). It was originally invented to describe logic made from
relays. The name is based on the observation that programs in this
language resemble ladders, with two vertical "rails" and a series of
horizontal "rungs" between them.

3. Traffic light simulaton

4. INTRODUCTION:
Traffic lights alternate the right of way accorded to road users by displaying
lights of a standard color (red, yellow/amber, and green) following a
universal color code.
In the typical sequence of color phases:
• Illumination of the green light allows traffic to proceed inthe direction
denoted,
• Illumination of the yellow light denoting, if safe to do so, prepare to
stop short of the intersection and
• Illumination of the red signal prohibits any traffic from proceeding.
• Usually, the red light contains some orange in it hue, and the green
light contains some blue, for
the benefit of people with red-green color blindness.
 Traffic lights have become an integral part of human’s day-to-day life.
 With this motivation in the mind, this project aims at designing and
implementing, a running model of traffic light controller which is
controlled according to the density of vehicle on road.
We will use AT89s52 microcontrollerand Infra red sensorfor performing all
the computation and control related task

5. HISTORY:-
• Traffic lights are signaling devices positioned at road
intersections, pedestriancrossings are today used in almost every city
of the world.
• On December 10, 1868, the first traffic lights were installed outside
the British houses of parliament in London,bythe railway engineer J.P.
Knight.
• The modern electric traffic light is an American invention,
policemanLesterWire invented the firstred-greenelectric traffic lights.
• The first four-way, three-color traffic light was created by police
officer William Potts in Detroit.
WHERE TO USE TRAFFIC SIGNAL?
General Traffic Volumes:- When traffic volumes at most of the intersection
approaches reach the point where other forms of control cannot efficiently
assign right of way to the approaching motorists.
Interruption of Continuous Traffic - Whentraffic on a major streetis so heavy
that traffic on a lightly travelled side street has little opportunity to cross or
enter the main-street traffic. This condition requires heavier traffic on the
main street than the previous condition, but allows lighter traffic on
the side street. Pedestrian Volumes - When pedestrian traffic is heavy
enough to justify the interruption of vehicular traffic.

6. SchoolCrossings -If judged necessarybythe traffic engineer,a traffic signal
may be used to facilitate the crossing of school children.
Progressive Movement - Sometimes a traffic signal will help keep platoons
of cars tightly formed to enhance the coordinated flow along a street and
encourage an appropriate speed.
Accidents -Traffic signals are sometimes effective in reducing accidents that
result from the inability of motorists to safely assign their own right of way.
These accidents typically involve right-angle collisions.

7. PURPOSE
 Control up to 4-phases traffic system with the traffic flow optimization
strategies
 Optimize the traffic flow at network junctions
 Measurably improve traffic flow
 Reduce environmental pollution caused by traffic
 Most importantly increases road safety
Traffic Light Design
• We figured out some possible States of the Traffic Light.
• Next, we should think logically about how the Traffic Light should
behave.
• For now, we will try to keep it simple.
• (Suppose these are infrequently usedcountry roads.)
ENHANCEMENT
• Bright and energy-efficient – street lighting
• Image processing
• Solar panel
Bright and energy-efficient – street lighting
 The challenge
◦ Limited public funds

8. ◦ Strict regulations
◦ Environmental protection
 The solution
◦ Contribute to public safety and security on streets and sidewalks
◦ Reduce the risk of accidents on roadways, cycle paths and
sidewalks
◦ Makes a city more attractive, improves the quality of life

9. SOFTWARE USED
All Control Logix and Compact Logix processors use LogixPro 500
software to program the PLCs. Admittedly, the software is a bit pricey,
but in my opinion, it is worth it.
Getting The LogixPro 500 Software
If you don’t have access to a PLC, it would be well worth the effort to
download the demo version of LogixPro 500. The demo runs for 90 days,
and has some limitations, but you will be gaining experience with the real
thing. Currently, the software is here:
http://www.rockwellautomation.com/rockwellsoftware/design/logixpro500/dem
o.htm

12. CONCLUSION
 Use of PLC instead of other controllers such as microcontroller makes
the smart traffic controller hardware a low cost system
 The program downloaded into the microcontrollerenables it to have a
high accuracy timing, high independency and consistently
 It enables the proposedsmart traffic controller system to realize traffic
flow optimization strategies at a single or network junctions