Transcript NAVI-LIGHT: - Stony Brook University Welcome

NAVI-LIGHT:
GPS based Embedded System for
Backtracking in Unfamiliar Environments
Ashray Solanki, Antony Pollail, Lovlish Gupta
Undergraduate Students,
Computer Engineering
Advisor: Alex Doboli, Assistant Professor
Electrical and Computer Engineering Department
Definitions
• Backtrack
• To go back over the course by which one has come
• GPS
• Global Positioning System (GPS) is a world-wide radionavigation system formed from a constellation of 24
satellites and their ground stations
• Time-to-first-fix
• Amount of time it takes the GPS receiver to start producing
solutions
• Embedded System
• A complete computer on a smaller scale which contains a
microprocessor, memory, I/O ports and sensors
Technical Description
•
•
•
NAVI-LIGHT is an embedded system based,
innovative flashlight used for navigation
Primary function is to
1. record the user’s starting point
2. trace the path taken
3. display the path back to the user
NAVI-LIGHT is a compact portable device that
can be easily controlled
Technical Description
• Records the user’s path by choosing between a
GPS receiver or digital compass based on the
availability of a GPS signal
• Implements a software controlled backtracking
system for situations in which a GPS module
would be ineffective
Operating Environment
• NAVI-LIGHT is designed to operate under
normal weather conditions
• Operating temperature is between 0° Celsius
and 60° Celsius
• Storing temperature is between -40° Celsius
and 70° Celsius
Design Requirements
• Main objective of the design is a navigational
tool that displays the path taken by the user
• Primary objective combines the design with
the integration of a compass sensor, a GPS
module and embedded system
• Secondary objective involves software
programming and debugging to interface the
components together
Approach and Design
• Design and develop a system level diagram of
the components necessary for implementing
the navigational flashlight
• Components were chosen to be of low power
consumption and minimal size; allowing them
to be embedded in a portable flashlight
Assumptions
• Vector 2X digital compass has a 2-degree
accuracy and must measure the Earth’s field
in the plane which is level
• The M12 Oncore GPS receiver has a cold
time-to-first-fix of no greater than 60 seconds
and a positioning accuracy of less than 25
meters
Assumptions
• Assumed that the user will operate the GPS
receiver outdoors and obtain a signal from at
least three satellites
• Implementing a velocity sensor to measure
the user’s exact distance would yield more
accurate results in backtracking mode
System Design
Software for
backtracking and
GPS mode control
DATA
8
Vector 2X
Digital
Compass
+5V
SBC1190
TTL to RS232
Embedded System
GPS
Module
to GPS
Antenna
SBC1190 Embedded System
• Ready-to-run embedded PC
• 128K RAM, 256K flash
• Small PC/104 format and
expansion
• Two RS232/RS485 COM ports
• 24 TTL-compatible I/O Lines
• 5V - only operation
Vector 2X Digital Compass
• Complete compass module
• Easily integrates with
embedded systems
• Small in size
• High accuracy
• Ease of calibration
• Low power consumption
• Low cost
M12 Oncore GPS Receiver
• Ready for software and
systems integration
• Small in size
• Low cost
• Quick implementation
• Low power consumption
• Fast time-to-first-fix
Operational Flow Chart
System Initialization
button
not
pressed
Run Mode
Check Button Pressed?
if button is pressed
start tracking
Check GPS Status
Backtrack Mode
GPS Mode
Display Results
on LCD Display
return to
run mode
Backtracking Flow Chart
Calculate heading
from compass
Record heading
if heading
has changed
Delay
Check if heading
has changed
Record time
of current heading
based on delay
Check if button
is pressed to
terminate tracking
Return to Main if button is pressed
if button is
not pressed
GPS Flow Chart
Get GPS coordinate
in form of string
Seperate string into
seperate arrays
Record GPS coordinate
Delay
Check if button
is pressed to
terminate tracking
Return to Main if button is pressed
if button is
not pressed
Status and Future Plans
• Present:
- Interfacing components of design
- Coding software for backtracking and GPS
• Future Plans:
- Implement a velocity sensor to calculate
distance traveled with a given degree
parameter
- Implement a battery pack to make the
NAVI-LIGHT portable