Traffic Light Control System

PROJECT PRESENTATION

ROHIT KASHYAP

ABHISHEK SINGH

VIRENDRA KUMAR

MEENAKSHI TRIPATHI

The controller to be designed controls the traffic lights of a busy highway (HWY) intersecting,

a side road (SRD) that has relatively lighter traffic load.

Sensors at the intersection detect the presence of cars on the highway and side road.

Forty to fifty years ago when traffic volume was lighter, the main job of traffic light systems was to manage peak traffic during the day .

The lights were centrally controlled, and not programmed to adjust in real time.

They were mostly optimized for pre-established assumed situations.

Our aim is to design an error free traffic control system that Safely, effectively directs traffic for streets intersection. The concern is minimization of traffic congestion, better regulation of traffic and minimization of travel time.

Advantages are reduction in vehicle operating cost, more efficient use of engines , lower environmental pollution from vehicle emissions, safe regulation of traffic in rush hour as well as in normal

daily traffic.

The system should have complete reliability confirming the timing of lights which must not cause accidents and safe crossing of pedestrians.

Major design issues of traffic control system include traffic bottlenecks, priority of pedestrian crossing, and easy implementation of changes along with reliable and sustainable design

Xilinx tools : - 1. Project navigator.2. Modelsim simulator

Hardware used FPGA kit

VHDL :VHSIC [Very High Speed Integrated Circuits] hardware description language.

•VHDL was developed as an alternative to huge, complex manuals which were subject to implementation-specific details. • VHDL supports description of components as well as systems at various levels of abstraction- Gate and component delays, Clock cycles, Abstract behavior• A basic VHDL code has following structural components:1.Libraries e.g :IEEE.STD_LOGIC_1164.ALL2.Entity – contains I/P and O/P declaration bits3.Architecture – contains all logic.

Interface(entity Declaration)

BODY(Architecture)Sequential

combinationalProcess

Subprograms

Ports

VHDL Entity

VHDL Examples: AND Gate

entity AND2 is port (a, b: in bit ; c : out bit); end AND2;

architecture beh of AND2 isbegin c <= a and b;end beh;

AND GATE

a

b

c

S<=A+B

Behavioral

Dataflow

Structural

(components interconnections)

Levels of abstraction: Behavioral, Structural and Physical

Physical

Implementation

VHDL is a parallel language while C is procedural language. Each statement occurring in VHDL is executed concurrently i.e. all statements run simultaneously .

In C/C++ each statement is executed in sequential order and its own turn., In VHDL explicit constructs exist for sequential steps.

VHDL allows use of explicit time delay, which is not applicable in procedural language.

VHDL model cannot be implemented in real time application directly like other procedural languages. It is simulated and synthesized using in built in system clock.

Logic optimization

Technology mapping

Placement

Routing

Programming Unit

Configured FPGA (Field-Programmable Gate arrays)

Initial design entry

Design flow of an Integrated circuit

A field-programmable gate array (FPGA) is a semiconductor device that can be configured by the customer or designer after manufacturing—hence the name "field-programmable".

FPGAs are programmed using a logic circuit diagram or a source code in a hardware description language (HDL) to specify how the chip will work.

They can be used to implement any logical function that an application-specific integrated circuit (ASIC) could perform, but the ability to update the functionality after shipping offers advantages for many applications.

Clock – process is edge triggered ,therefore states change for every transition of 0 to 1 .

Reset – the process initiates for binary value 1, further the value is set to low.

Sensor - the value 1 signifies more traffic load, hence duration of green light increases .

The states depend upon the following port values :

“Smooth sea never made a skilled mariner”

Hence the constant cross checking of knowledge and guidance is provided by Mr. P.K. Bharti (H.O.D. Computer science) and Mr. Amit Goswami (mentor), Mr.Virendra kumar.

 ROHIT KASHYAPMEENAKSHI TRIPATHIABHISHEK SINGHVIRENDRA KUMAR