firefighting vehicle by: scott benjamin & reji jose
Post on 21-Dec-2015
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TRANSCRIPT
Description & Objective
Navigate through 4’x4’ structure.
Search for a lit candle. Extinguish by a fan onboard.
Reference Page 1, Appendix A
Firefighting Vehicle
PN168 PN168PN168
HCS12
GP2D120 GP2D120GP2D120
Plexiglas Base
151440151440
CPU fanLightweight wheelLightweight wheel
Operation Range Motor operates between 4.5 – 12 volts
and draws 225mA at maximum efficiency.
Operating voltage of battery: 1.1 - 1.3V Operating current of H-Bridge: 0.6 - 1A Operating voltage of HCS12: 4.5 – 5.5V
Reference Pages 4, 8, 10, 12, Appendices B, C, D
IR Sensors Sharp GP2D120 Detects objects between 4cm-30cm
HCS12
0 1 2 3 4 5 6 7Port AD
4 cm4 cm 4 cm
GP2D120
Reference Pages 9-11, Appendix D
Motor Drive Current peaks at 275 mA each motor adds 2.2Kg-cm of torque Rotates at ~1 revolution per second
Breadboard151440
151440
Reference Pages 3-4, Appendix B
System Initialization
Wait half a second for sensor startup.
Flash all LED’s once for ~0.3 seconds.
Keep all LED’s lit upon error or crash.
Reference Pages 15-16
User Interface0000000
1 Looking for the candle
00000010 Found Candle
00000100 Trying to put out the candle
00001000 Detected the candle to be out
00010000 Detected a wall in the way
00100000 Turning left
01000000 Going straight
10000000 Turning right
11111111 Light all LEDs at start up or after an error
Reference Pages 15-16
Operating Restrictions
Non overhead lighting may cause problems.
Walls need to be at least 10 inches apart.
Software Flowchart
Move
Candle Out yet?
Start
End
Overall Flow
Start
Is the square ahead clear?
Move one square ahead
End
Yes
Yes
No
No
Go back to start
Move Algorithm
Start
Turn Algorithm
Turn Left
Turn
Is the square ahead clear?
Backout
No
Yes
Move one square ahead
Turn Right
End
Start
Backout Algorithm
Turn Left
Is the square ahead clear?
Move one square ahead
End
Turn Right
Yes
No
Reference Pages 13-14
Difficulties Sensors may not sense the obstacle
within the given range. Sensing the flame and blowing it
out. Make sure that the data from the IR
sensor is read in correctly. Making sure power consumption is
not too high.
Reference Pages 17
Testing Procedure Test each component individually:
Motors IR Sensors Phototransistors H-Bridge Batteries Software
Then test Integration
Reference Pages 4-5, 6-7, 8, 11, 13
System Integration Each subsystem will already be
tested for correctness Place vehicle in operating
environment First test base functionality (find and
extinguish candle) Simultaneously, ensure that the user
interface functions properly Finally, confuse it
Reference Page 16
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