Traffic Control System

Published on June 2016 | Categories: Types, Instruction manuals | Downloads: 40 | Comments: 0 | Views: 302
of 29
Download PDF   Embed   Report

Comments

Content

The Problems associated with traffic junctions
 





The total number of motor vehicles in this world is 600 million. It is estimated that on an average a person spends 2mins, 12 seconds per day waiting in a traffic junction. That is , a person spends an equivalent of 1.32 kms a day waiting in a traffic junction a traffic junction. That is a total of 810 million kms of distance that is lost waiting at traffic junctions. More importantly , the total cumulative time spent waiting at traffic junctions is 1. 2 million minutes per day. This deals a severe blow to the efficiency of any system .

Problems contd.
Also , estimated .21 liters of fuel are wasted by a person waiting at traffic junctions. That is , 100 millions liters of fuel per day alone. In money terms, it comes to 75 millions dollars per day  All these calculations are for a per day basis. Imagine the consequences we could have if these calculations were extrapolated for a week, month or a year.


Present system of traffic management at junctions
Pre-timed signal timer values (red and green) are installed at various junctions based on predicted flows and variations of traffic flows.  Also , an anticlockwise pattern of allowing traffic from each of the of the four roads of the junction is followed.


The disadvantages with the present system.






The delay is not distributed evenly among all the sides of the traffic junction. i.e., there is always at least one side of the junction that needs to wait longer than required ( excess red time) and one side of the junction that is given excess go time ( green time). The signal timer values are constant for most of the day with very little variation. It is common knowledge that traffic flow variations are unique for that time of the day Also , traffic flows vary from day to day ( for eg – difference of flows from weekdays to weekends). The present system does not factor this in account

Disadvantages contd..
Any untoward incident ( like an accident by the side of the road will affect traffic flows. The present system does not take this account also  This is where we would like to introduce our system – efficient dynamic scheme generation for traffic timer values


Proposed improvement.








This system is adaptable to the present conditions and it does not alter the function of the roadways and the construction of roads. Real time dynamic queue length changes are taken into account. Dynamically altering Timer values based on instantaneous traffic conditions promises optimal time allocation and sharing of time delay between all road users. Three innovative modules that make the system efficient.

The three Modules
Adaptive module that senses the dynamic changes in queue length at individual lanes at a typical four way six lane intersection.  Predictive Module that obtains data from the database at similar conditions minimizes the use of camera and processing thereby saving energy.  Dynamic Plan Generation that controls traffic based on random changes in the traffic density in different lanes.


BLOCK DIAGRAM

Camera and Processor

Signal time Estimation Module

Signal Plan Design

Signal Controller

Traffic Lights and Timer

Database

Adaptive module
As told before, the adaptive module is used to sense the number of vehicles at a traffic junction instantaneously and dynamically vary the traffic timer values.  This would involve three steps. Capturing of instantaneous images at traffic junctions using cameras, image processing of these photographs to find out the number of vehicles and finally , conversion of vehicle count to time values.


CAPTURING OF IMAGES
The pictures of the traffic conditions were taken using a 3.2 MP digital Camera.  The software used for processing is UTHSCSA Image Tool.  Involves four steps – Subtract Background, Background Subtraction, Intensity Thresholding and Object Detection.


SUBTRACT BACKGROUND

REFERENCE IMAGE SUB BACK

BACKGROUND SUBTRACTION

MANUAL THRESHOLDING

OBJECT DETECTION

RESULTS

DYNAMIC SCHEME GENERATION
 






Get the adapted values i.e. the timer values to be set for the green signal at each direction. The algorithm was implemented using a C++ program that generates a scheme for a typical 4way 6-lane narrow road traffic junction. The program focuses on selection between possible schemes. Different programs have to be coded for different signals. The program aims to replace a traffic constable by automatically routing traffic.

FLOWCHART
Start Determine Signal Plan and Topology

Determine all possible schemes

Get adaptive values

Are all signals accounted?

Yes

Arrange in Descending order
No I=1 Check relevant conditions and select appropriate scheme

Any value repeated? No Display and execute schemes

Yes

Get new adaptive value

Stop

8 POSSIBLE SCHEMES
S.NO 1 2 3 4 5 6 7 NE,NS, NW,WN NE,NS, SW,SN WN,WE,WS,SW WN,WE,ES,EW SW,SN,SE,ES SW,SN,N\E,NS ES,EW,EN,NE SCHEME 1,2,3,4 1,2,7,8 4,5,6,7 4,5,10,11 7,8,9,10 7,8,1,2 10,11,12,1 NOTATION

8

ES,EW,WN,WE

10,11,4,5

RESULTS

CONVERSION OF COUNT TO TIME






Once the number of vehicles , we now have to convert the count to time for the signal at that point of time. This can be achieved through extensive collection of data in the actual traffic flows for different set of boundary conditions to find out the clearing time of all vehicles. After this, an appropriate statistical or mathematical function can be used to estimate the clearing time according to the queue length.

Sample of actual field data
Number of vehicles 17 21 22 28 28 Clearing time 10 11.22 16.27 18.48 14.23

32
34 36 46 51 52 52 58 69 69 75

17.56
12.53 17.67 17.09 18.67 30.36 16.44 30.96 33.55 26.75 34.53

ACTUAL CLEARING TIME
Number of vehicles 0-10 10-20 20-30 30-40 40-50 50-60 >60 and < 75 Clearing time function Number of vehicles * .8 Number of vehicles * .7 Number of vehicles * .65 Number of vehicles * .6 Number of vehicles * .55 Number of vehicles * .5 Number of vehicles * .45

 If the leading vehicle in the queue is a car or any other 4

wheeler = add 3 seconds to the clearing time  If the leading vehicles in the queue is a bus, lorry or a similar sized vehicles = add 6 seconds to the clearing time

ADVANTAGES
Instantaneous variations in traffic conditions are taken into account.  Dynamic scheme generation spreads the delay equally between the road users at a junction.  The system adapts itself to the Indian traffic conditions.  Indirect advantage of a traffic monitoring and security system.


FUTURE RESEARCH
Method to detect the number of Pedestrians.  Networked Navigation system to obtain a complete control over all junctions in the city.  Design of a Combined Traffic control and Security system.  Mapping of movement of vehicles onto a grid network.  Use of multiple sensing Technology to improve accuracy.


References
 



http://www.doityourself.com/info/trafficsignals Nature of traffic at various places around the world “Adaptive Signal Control II”, Dr. Peter T. Martin, Ph.D. Associate Professor, Joseph Perrin, PE, Ph.D., PTOE, Assistant Associate Professor, Bhargava Rama Chilukuri, Chantan Jhaveri, and Yuqi Feng Research Assistants Department of Civil and Environmental Engineering, University of Utah Traffic Lab. http://eeweb.poly.edu/~onur/lectures/lecture1.pdf Online lecture notes on DIP by Onur G. Guleryuz, Department of Electrical and Computer Engineering, Polytechnic University, Brooklyn, NY

References contd..




http://www.cs.dartmouth.edu/~farid/tutorials/ Online tutorials on MATLAB and Image Processing 8051 Microcontroller : Architecture, Programming and Applications by Kenneth Ayala

THANK YOU

Sponsor Documents

Or use your account on DocShare.tips

Hide

Forgot your password?

Or register your new account on DocShare.tips

Hide

Lost your password? Please enter your email address. You will receive a link to create a new password.

Back to log-in

Close