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Company
LOGO
Safety Road Crossing System
For Blind People
Final Year Project Presentation
By M.H.I.M Aththanayke
IESL Part III-C
Supervisor: Mr.Dhammika Perera
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Content
Background of the projectIntroduction(Why,How)
System Design
Onsite InstallationSystem Testing
Cost Analysis
Conclusion and Further Developments
Acknowledgement
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Background of the project
If a visually impaired person chooses to walk, evencrossing the road is a big challenge, Most of ourtraffic lights are not visually-impaired friendly.
Modifying the existing traffic lights to emit audio
signals to help the visually impaired is prohibitivelyexpensive.
Solution is to device an attachment to be mounted
on the existing traffic lights to give signals tovisually impaired people will be feasible one.
Sri Lankan government come up with new idea tomake the government facilities accessible for the
disabled cause disabilities of the war heroes. 3
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Introduction
Sri Lanka's blind populationis estimated tobe between 92920 and 150000
Thousands of them are facing enormous
number of issues when they are crossingroad
Providing an safety device for above
mentioned portion of people in the societyis an vital requirement
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Why?
Commercially launched such devices arerare to find and those are so expensive
Munivo is one of the product, but it is
only for object detecting and moreexpensive as well.
Current Road Crossing system not
support to the blinds.
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How?
created a cost effective & Reliabilitydevice that will allow people with visiondisabilities to cross the street safely
The devise will not be a sign of blinds likea white cane.
The idea behind this project is to provide
more cost effective efficient and accuratedevice for the blind people that would helpthem a lot.
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System layout
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Transmitter Freq:50KHz Transmitter Freq:50KHz
Transmitter Freq:50KHzTransmitter Freq:50KHz
Transmitter Freq:25KHz
Transmitter Freq:25KHz Transmitter Freq:25KHz
Transmitter Freq:25KHz
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System Design
Safety RoadCrossing System
Transmitting UnitPower Source
Receiving UnitTransmitting Unit
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Transmitting unit Power Source
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Transmitter unit
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Continue
Transmitting unit consist of two devices basically:
RF signal Transmitter unit.
WALK signal detection unit (Using LM741)
The walk signal triggers the LDR circuit at the beginThe LDR gives 5V as its output to the
microcontroller input pins.(Two inputs from two)
Microcontroller identify which transmitter have to betrigger according to the received input signal.
Hence transmitter is transferring the RF signals inexact frequency (25kHz,50kHz)
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Walk signal
There are two types of lights that are usingin all the city signals:
Tungsten bulbs
LEDs
+5V
+5V +5V
R4 1K
R1 1M
+
-
U1
LM741
3
26
7
1 4 5R6
POT
R3 1K
R2LDR
R5
1K
Sen_SigDetect
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Continue
There are three main devices exist in tothe receiver unit:
RF signal receiver unit
Vibration motor Dry cell power supply
Receiver unit is check for the signal from
three possible directionsIt is sent out the direction for the user
when the walk signals are on
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Receiver Block Diagrame
Three antennas, Microcontroller andVibrator
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M: Middle Receiver antenna to detect the
signal coming from the Front
L: Left Receiver antenna to detect the
signal coming from the Left
R: Right Receiver antenna to detect thesignal coming from the Right
RL
Power UnitMicrocontroller
Vibrator
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State diagram for the microcontroller ofthe receiver
Receive signals from
the antennas
Check
Signals
F NF B
Vibration
010
001
100
101
011
110
111
000
Reset
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L M R0 0 0 X0 0 1 NF0 1 0 F0 1 1 B1 0 0 NF1 0 1 NF1 1 0 B1 1 1 B
Receiver antennas directions truth table
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Vibration Patterns
If only the street was safe, the motorwould vibrate in short pulses on right, left,front or both
If only the person near the safe blindcrossing system with no WALK signal itsvibrate with continuous vibration with nobuzzer
If there is no safety system nearby thenthe three directional vibrations would becontinuously vibrate with buzzer
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Vi f th t itt d
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View of the transmitters andReceiver together
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Continue
Installation image
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System testing
Checked the operating vibration patterns
Test Results
Checked the operating vibrationpatterns
Long vibration with the buzzer
Transmitter on Buzzer off & long vibration
100kHz Idle state
25kHz Vibration
50kHz Vibration
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Continue
Directivity and range of TransmitterAntennas
Tested values showed that its having
approximate 20 degree bandwidth value whentransmitting
40m maximum transmission range increases theaccuracy of the system.
Needs to use small metal disks to guide RF mainglobe and avoid Omni directional transmission.
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Transmitter frequency Checking
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Transmitter when WALK signal is on
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Transmitter when WALK signal is off
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Receiver without receiving RF signal
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Receiver receives from right side
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Cost analysis
Item Quantity Part Unit Price Price1 1000uf(25V) 2 15.00 30.002
100nf
1
1.50
1.50
3 220uf 1 8.00 8.004 0.1uf 1 1.50 1.505 15pf 2 1.00 2.006 1N4007 5 3.00 15.007 Connector 2 16.00 32.008 LED 4 2.00 8.009 Buzzer 1 45.00 45.00
10 470K 3 0.25 0.7511 1K 2 0.25 0.5012 20K Preset 2 5.00 10.0013 10K 1 0.25 0.2514 330 1 0.25 0.2515 LM317 1 20.00 20.0016 LM7805 1 18.00 18.0017 PIC16F877A 2 400.00 800.0018 4Mz 1 22.00 22.0019 1M 1 0.25 0.2520 LDR 1 19.00 19.0021 1K 3 0.25 0.7522 POT 1 5.00 5.0023 LM741 1 18.00 18.0024 40 Pin IC Base 1 20.00 20.0025 400mA Transformer 1 140.00 14026 AC Code 1 45.00 45.0027 PCB 1 450.00 450.0028 Tx Unit 1 750.00 750.0029 Rx Unit 1 750.00 750.00
30 12v 3W solar panel 1 1800.00 1800.00TOTAL 5012.75
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Conclusion and further
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Conclusion and furtherdevelopment
Restructuring the empowering unit to bemore cost efficient, using less space, andpreventing interference from other devices
Creating the Buzzer warning alarm for lowbattery state will increase the systemreliability
Adding a narrow beam antenna totransmitter for avoid Omni directionaltransmission
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Continue
Need to use advanced PCB mountingtechniques to minimize the receiverdimension such as double side surface
mountingNeed to mount the receiver unit
microprocessor on vibration free surface
for durability
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Acknowledgement
Project Supervisor:Mr.Dhammika Perera
Deputy General manager
Data & Access network operations
SLT Head Office
Colombo-02
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W
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Q & A
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THANK YOU!
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