Design Flow

1
Emergency Vehicle Detector for use in Consumers
Motor Vehicle
Ehren Bendler, Jose Crespo, Tyler Evans, Richard
Yee
Georgia Institute of Technology School of
Electrical and Computer Engineering ECE 4007
December 2, 2008
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Project Overview

• EMV Detector warns motorist of approaching EMV
• EMVs are involved in thousands of accidents per
  year that are preventable with proper warning
• EMV Detector can be used by any motorist
• Total estimated cost of project is 51,406.25
  including labor and equipment

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Design Objectives

• Captures audio from outside of vehicle
• Processes signal to determine if EMV is
  approaching
• Detects siren 5dB over ambient noise
• Refreshes at an average rate of 2-3 seconds
• Use audio and visual (LED) warnings
• Uses relay to cut power to radio

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Marketing/Cost Analysis

• Total Labor cost of approximately 32,900.00
• Equipment cost of approximately 159.37
• Fringe benefits calculated at 8,225.00
• Overhead cost of 10,321.09
• Total cost of the project is estimated at
  51,605.46
• Selling cost of 175 and 100,000 units sold for 5
  years equals a profit of 1,511,394.54.

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Design Flow
No
Siren Approaching?
Input Audio
Yes
Shut Off Radio
Output Warnings
Car Radio
Siren Moving Away?
No
Yes
Give All-Clear
Turn On Radio
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Siren Sounds
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Detection Algorithm

• Implemented in MATLAB
• Performs FFT on audio input
• Looks for siren frequency peaks
• Frequency range includes Doppler shift of
  velocity up to 60 MPH
• EMV is approaching if siren is present for 2
  seconds
• EMV has passed if siren is absent for 3 seconds

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System Diagram
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Computer Specifications

• Motherboard Intel D945GCLF2
• 4 USB 2.0 ports
• Integrated VGA output
• Realtek ALC662 HD Audio
• Processor Embedded Intel Atom 330
• 2 cores at 1.60GHz
• Memory 2GB DDR2-667

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LED Controller

• Cypress CY8C29466
• Supports RS-232 Interface
• Supports Analog and Digital I/O
• Easy to program
• Pre-installed on Cypress PSoC Evaluation board
• Board supplies LEDs and LCD

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Problems

• Most recent problem was getting false positives
  from voices
• Due in part to the way the Hi-Lo siren was
  detected
• Fixed by using the third harmonic of the siren to
  eliminate false detection

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Project Schedule

• Finished hardware and software 10/31
• Write final project summary 12/4
• Demonstration 12/2
• Write final project report and finalize website
  12/5

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Current Status

• Detects all four siren types
• Plays an audio message when a siren is detected
• Displays message on LCD
• Relay cuts power to radio when siren is
  detected

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Results
Desired Actual
Detection level 5dB over ambient noise 4dB over ambient noise
Refresh time 2 seconds 2 seconds
Size (L x W x H) 6 in x 6 in x 1 in 12 in x 12 in x 3 in
Distinguishing EMV types Yes No
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Future Work

• Port Matlab code to C or C
• Further integrate hardware
• Add ability to locate siren directionally
• Add ability to distinguish between types of
  emergency vehicles