Traffic Light Traffic Light ControllerController

Presented To:Presented To: Sir. Waseem NazarSir. Waseem Nazar

H.O.D Electronics Dept.H.O.D Electronics Dept.Presented By:Presented By:

M Tahaa EE106013M Tahaa EE106013 Usman Naseem EE305043Usman Naseem EE305043 Sohaib Amar CH. EE3306030Sohaib Amar CH. EE3306030 M Zulfiqar Saeed BE107901M Zulfiqar Saeed BE107901

Traffic Light Controller Traffic Light Controller Basic FunctionalityBasic Functionality

Intersection of roads:Intersection of roads: Highway (busy);Highway (busy); Country Road (not busy).Country Road (not busy).

Want to give green light to highway as much as Want to give green light to highway as much as possible.possible.

Want to give green to country road only when Want to give green to country road only when needed.needed.

Want to give red to highway road only when car Want to give red to highway road only when car or pedestrian arrives.or pedestrian arrives.

Must always have at least one red light to avoid Must always have at least one red light to avoid accidents.accidents.

System operationSystem operation

Sensor on country road indicates Sensor on country road indicates when car’s on country road are when car’s on country road are waiting for green light.waiting for green light.

Must obey required timings for Must obey required timings for green, yellow lights.green, yellow lights.

All operation is controlled by the All operation is controlled by the clock.clock.

Highway

Country Road

Sensor

ScenariosScenarios

1.1. If only Car or Car & Pedestrian approaches If only Car or Car & Pedestrian approaches on Country Road & Highway respectively.on Country Road & Highway respectively.

2.2. If only Pedestrian approaches on Highway.If only Pedestrian approaches on Highway.1.1. Car Doesn’t Arrive at all.Car Doesn’t Arrive at all.

2.2. Car Arrives after Highway Signal gets Yellow.Car Arrives after Highway Signal gets Yellow.

3.3. Car Arrives after Highway Signal gets Red.Car Arrives after Highway Signal gets Red.

1.1. If only Car or Car & If only Car or Car & PedestrianPedestrian

approaches on approaches on Country Road & Country Road &

Highway respectively.Highway respectively.

Highway

Country Road

Sensor

After max. 25 Seconds

Sensor Checks for Vehicle on Country Road or

Pedestrian on Highway

Highway

Country Road

Sensor

Sensor Detects a Vehicle on Country Road

Highway

Country Road

Sensor

After 4 Seconds

Highway

Country Road

Sensor

After max. 25 Seconds

Or as soon as Car or Pedestrian Crosses Highway

Highway

Country Road

Sensor

After 4 Seconds

Highway

Country Road

Sensor

At this stage it should be noted that if a car At this stage it should be noted that if a car is still on Country Road even after the 25 is still on Country Road even after the 25

Sec. Then it will have to wait for another 25 Sec. Then it will have to wait for another 25 seconds till the Sensor detects it again and seconds till the Sensor detects it again and

Stops the Highway Traffic !Stops the Highway Traffic ! Same case for Pedestrian.Same case for Pedestrian.

2. If only Pedestrian 2. If only Pedestrian approaches on approaches on

Highway.Highway.

Highway

Country Road

Sensor

After max. 25 Seconds

Sensor Checks for Vehicle on Country Road or

Pedestrian on Highway

Highway

Country Road

Sensor

Sensor Detects a Pedestrian on Highway

Highway

Country Road

Sensor

During 4 Seconds

If Car Doesn’t approach Country Road

If Car approach Country Road

Highway

Country Road

Sensor

During 15 Seconds

If Car Still Doesn’t approach Country Road

If Car approaches Country Road

After max. 15 Seconds

Or as soon as Pedestrian Crosses Highway

Highway

Country Road

Sensor

After 4 Seconds

Highway

Country Road

Sensor

During 4 Seconds

If Car approaches Country Road

Highway

Country Road

Sensor

After max. 25 Seconds

Or as soon as Pedestrian and Car Crosses Highway

Highway

Country Road

Sensor

After 4 Seconds

Highway

Country Road

Sensor

During 15 Seconds

If Car approaches Country Road

Highway

Country Road

Sensor

After max. 25 Seconds

Or as soon as Car or Pedestrian Crosses Highway

Highway

Country Road

Sensor

After 4 Seconds

Highway

Country Road

Sensor

Main:Red Side:Red

Main:Red Side:Red

Main: Green Side:Green

Main:Red Side:Green

State Diagram Of The Signals

1st State 000Main: Green

Side: Red

2nd State 001Main: Yellow

Side: Red6th State 101Main: RedSide: Red

TL ( VS + + PM )

TS

TS

(TL + (TL& (VS + PM))

• Vehicle present on side street = Vs

• Pedestrian present on Highway = PM

• 25 s timer (long timer) is on = TL

• 15 s timer (Pedest. timer) is on = TP

• 4 s timer (short timer) is on = TS

Main:Green Side:Red3rd State 010Main: RedSide: Green

Main:Red Side:Green5th State 100Main: Yellow

Side: Red

Main:Red Side:Green7th State 110Main: Yellow

Side: Red

TS

(TLVS ) or (TLVSPM)

(TL PM)

TL& (VS + PM)

4th State 011Main: Red

Side: Yellow

TSVS

TS

TS

TPVS

TP + PM

TP PM

TS

TS

TS

The End