Wireless Controlled Toxic Gas Detecting Robot
Final Presentation & Demo
Amrinder Chawla, Anurag Kadasne, Saurabh Pandey, Enkuang “Daniel” Wang, Gowtham Tamilselvan, Robert “Kyle” Brown
ECE 4007 L03: Prof. Erick Maxwell 7th December, 2010
Project Overview
Design and Cost Objectives
Hardware and Software
Results
Challenges
Schedule and Future Work
Project Demonstration
Agenda
Combines wireless robot navigation and live video
Detects and provides feedback of CO concentration in ppm
Allows emergency teams to respond to gas leaks
Reduces human exposure to CO gas
Provides relief materials to the affected
Costs $142.98
Project Overview
Gasbot Setup
Remote Computer
Webcam
Safety Kit
eBox iRobot
mbed microcontroller Parallax CO
Sensor
Gasbot Setup
Design Objectives
Objectives StatusLive video streaming Met
Detects concentration of CO MetSafety box for emergency assistance
materials Met
Easy to use Graphical User Interface (GUI) MetPortable and easily navigable device Met
Total cost under allocated budget of $440 MetLive wireless feedback of gas
concentration Met
Proposed and Actual Design
Safety Kit
Gas Mask
CO Sensor
Camera
eBox
Front View of Gasbot
iRobot
eBox
CO Sensor
Camera
Project CostsComponent Actual Cost Cost To
UseBox $150 $0
iRobot $129.99 $0mbed microcontroller $60 $0
Parallax CO Gas Sensor Module
$29.99 $29.99
Safety Box $30 $30Logitech Pro 9000 Camera $40 $0
Glass Stand $2 $0Voltage Regulator $26 $26Connecting Wires $15 $15
Gas Mask $14.99 $14.99Butane Hair Curler/Torch $27 $27
Total Cost $ 524.97 $142.98
iRobot’s battery provides 16 V input voltage
Input voltage stepped down to 5 V using 78HT305 regulator
Stepped down voltage provides power to eBox
Battery Pack
Windows CE 6.0
Learning challenges
Failed hard disk
TA and Dr. Hamblen helped
eBox OS
Based on the work of Dr Hamblen
Can control Robot using WASD keys and P&L for speed
Keyboard based for easy operation
Remote Control GUI
Camera drivers were not compatible initially
When it started working, the camera broke (internal circuitry broke off)
New camera and compatible software
Camera Integration
Serial port – receive data from CO sensor
Character buffer
View exported using a built-in OS feature.
Export view feature: main factor for system choice
Serial Port Integration/Exporting View
CO Sensor and VR3 Value
15
VR3
VR3 increases as CO level increases
VR3 is read from pin TP1
Value is transmitted to mbed microcontroller
Transferring Data from Sensor to mbed
𝑹𝒔
𝑹𝟎=𝑽 𝑪−𝑽 𝑹𝟑
𝑽 𝑹𝟑,𝒘𝒉𝒆𝒓𝒆𝑽 𝒄=𝟓𝑽 .
17
PPM Plot
VC/(VC-VRL) PPM1.5 501 100
0.39 4000.215 10000.09 4000
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.60
500
1000
1500
2000
2500
3000
3500
4000
4500
f(x) = 95.5007032472264 x^-1.54306544971509
VC/(VC-VRL)
PPM
Equation Used to Generate PPM Values
Sending PPM Value to eBox
Serial Breakout Board
19
Calculated PPM is sent from pin 28 Value to sent to eBox via serial
breakout board
Room temperature condition
Set voltage of potentiometer R4 & R3 to approximately 0.8 V
R3 – voltage divider (buffered output of sensor)
R4 – threshold voltage
Sensor Calibration
R3R4
Butane hair curler – output varies from 50 ppm to few hundreds of ppm
CO canister – most accurate method, output ppm closely matches listed ppm (+/- 3 ppm)
Butane lighter – smaller range from 30 to 80 ppm
Car exhaust pipe – output fluctuates from 60 to 150 ppm
Sensor Testing Methods
CO canister is best method to measure accuracy
When tested with other methods, the ppm value fluctuates
Other methods only allow detection of change in ppm
Result and Accuracy
Listed PPM EHS Gasbot % Error36.1 35 38 8.57142950 54 58 7.407407
Safety Kit
Designed to maximize space and functionality
Used sign foam to build safety kit
Used acrylic cover for the back
Can hold a full size gas mask with filter and walkie-talkie
Problems and SolutionsDevice Problem SolutionCOM Port Transferring data Used buffer to show
charactersBattery Pack Not able to provide
power for long timeUsed a switching voltage regulator with higher efficiency
Sensor No testing source Use canister to testiRobot Space Built new connectors/
plexiglass standSerial Breakout Board
Data was not transferred Switched connections for rx and tx pins
Camera Circuitry damaged Replaced cameraCO Sensor Calibration issue Recalibrated using the
eBox
Product Research• eBox setup• Microcontroller• CO sensor• iRobot• Safety Kit
Integration• Wirelessly
controlled robot• Data transfer
between user and robot
• Testing
Finished Product• Final
presentation• Project
demonstration• Final project
report
Schedule
Late August – Early September
Mid September – Mid November
Late November – Early December
More toxic gas sensors
More accurate sensor
Different testing modules
Rotating platform for camera
Netbook instead of eBox
Faster Car
Future Work
Questions?