Transcript Emergency Vehicle Alert System

EMERGENCY VEHICLE ALERT SYSTEM
ECE 495C Digital Systems
Senior Design Project Proposal
Team #3 Spring 2008
January 09, 2008
Overview
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An emergency vehicle alert system would provide indication to motorists of
the presence of an emergency vehicle such as police, fire trucks, and
ambulances in their vicinity. The system is activated when the sirens of the
emergency vehicle are turned on. The emergency vehicle is equipped with
a GPS receiver to mark its location, and an RF transmitter to broadcast the
vehicle type (fire, police, medical, other) and its present GPS location to
surrounding vehicles. Individual motorists are equipped with a GPS receiver
of their own, and an RF receiver. The RF receiver will detect when an
emergency vehicle broadcast is being made, and thus an emergency vehicle
is in the area. An RF front end will demodulate the transmitted data. A local
microcontroller will calculate the distance, relative location, and direction of
travel of the emergency vehicle from their present vehicle location by
comparing the transmitted and local GPS data. An LCD screen and
speakers will alert the motorist of an emergency vehicle’s presence.
System Block Diagram I
LCD Vehicle / System
Info Display
GPS
Receiver
Microcontroller
FSK/PSK/ASK
RF Transmitter
Power Supply
Keypad ID
Activation Switch
Emergency Vehicle System (Transmitter)
System Block Diagram II
LCD Warning
Display
GPS
Receiver
Microcontroller
FSK/PSK/ASK
RF Receiver
Power Supply
Alert Speakers
Power Switch
Motorist Vehicle System (Receiver)
Additional Possibilities / Features
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Create secure open-channel communications broadcast. Such an application
may allow police to key in the license plate number of an offender, encrypt
and broadcast the plate number and the offender’s unit would signal that
they have been flagged to be pulled over. (FUN!)
Only allow use of transmitter by authorized individuals. May need to enter
identification number to unlock with keypad or other means such as
programmed RFID tag, fingerprint scanner, etc.
Programmable transmission range.
Interface with commercial GPS receiver map software to somehow overlay
location of emergency vehicle on display screen.
Technical Challenge – How to handle multiple transmissions / multiple
emergency vehicles.
Technical Challenges & Risks
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Determine how to handle multiple emergency vehicle alert transmissions.
Require multiple frequency bands?
FCC regulations for mid-range power (i.e. ~0.5 mile radius) RF
broadcasting.
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Determination of appropriate transmission modulation scheme.
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GPS receiver reliability
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Transmission interference
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Requires two microcontrollers
Project Positives
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Compact and efficient mechanical design very possible.
Tractable, interesting, but sufficiently difficult.
GPS receivers have well-defined NMEA RS-232 serial output code
standards for microcontroller interfacing.
Short range (~500 ft) RF transcievers readily available and inexpensive for
possible senior design course prototyping purposes.
Numerous possibilities for user interfaces. May use inexpensive and simple
keypads and LCD screens that have been well documented and used in the
past or may venture into larger displays.
Easy power supply design! Tap into vehicle 12 VDC power and use voltage
regulator to step down to 5 V for all components. No need for battery
backup circuit or AC to DC conversion from wall outlet.
Good amount of analog and digital work with reasonable number of
interfacing devices.