On

Submitted by

Banzadio salazaku

Roll 2013010100016

B tech E and I

6th sem

Submitted to

Mrs. Arti Nagpal

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.

Traffic light simulaton

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 in the 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 microcontroller and Infra red sensor for performing all the computation and control related task

HISTORY:-

• Traffic lights are signaling devices positioned at road

intersections, pedestrian crossings 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, by the railway engineer J.P.

Knight.

• The modern electric traffic light is an American invention,

policeman Lester Wire invented the first red-green electric 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 - When traffic on a major street is 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.

School Crossings - If judged necessary by the 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.

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

◦ 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

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

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 microcontroller enables it to have a high accuracy timing, high independency and consistently

It enables the proposed smart traffic controller system to realize traffic flow optimization strategies at a single or network junctions