Team 1617: Autonomous
Firefighting Robot
Katherine Drogalis, Electrical Engineering
Zachariah Sutton, Electrical Engineering
Chutian Zhang, Engineering Physics
Advisor: Professor John Ayers
Overview
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Project Overview & Contest Background
Mechanical Design & Layout (Overview from Fall Semester)
Navigation & Routing
Flame Search & Extinguish
o Mechanical
o Software
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Sound Activated Start
Budget
Autonomous Firefighting Robot
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Trinity International Robot Contest (April 2-3, 2016)
User initiated, autonomous start & navigation
Search for and extinguish burning candle
Design can be extended to real life situations
Trinity International Robot Contest
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8x8’ plywood maze
Arbitrary start position
Competing in 2 of 3 levels
Timed trials
Unique robot
31x31x27 cm robot
Level 1 Arena
Level 2 Arena
Test
Arena
Mechanical Parts / Structure (Fall 2015)
• Navigation
o 360o Laser Scanner
• Extinguishing
o 16*4 Thermal Array Sensor
o Compressed CO2
• Computing
o Raspberry Pi - navigation
o Arduino – motor control & flame extinguish
• Movement
o DC motors with encoders
• Power
o 16 V, 5500 mA/h rechargeable battery
Routing/Navigation
• Considered: SLAM (Simultaneous Localization and Mapping)
o Requires a lot of processing (slow)
• Speed / simplicity is important
• Now: Monte Carlo Localization with Grid Map
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Start with uniformly distributed “samples” or guesses of robot’s pose
Apply motion to all samples
Compare laser scan observation to sample observations
Weight samples based on similarity to laser observation grid map
Resample from newly weighted sample distribution
Global Map
MCL Simulation
Source: www.hessmer.org/robotics
ROS (Robot Operating System)
• Runs on Raspberry Pi
• Performs scheduling/parameter setting for various “nodes” or scripts
• Mostly prewritten/open source
o Saves on programming time
• Downloaded packages to be used together for navigation
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Localization
Laser scan processing
Global path-planning (get to goals)
Local path-planning (obstacle avoidance)
Calculate velocity commands
Communicate with Arduino
ROS Block Diagram
System Block Diagram
Flame Searching (Mechanical)
• Processing done on Arduino
• RoBoard 16X4 Thermal Array Sensor
o Produces a map of heat values
o Able to pick up the difference 1.5m away
o Field of Vision: 60º horizontal, 16.4º vertical
• Scan 360o
o If candle is detected, pivot to center on flame
o If centered, move forward to candle
o If no flame, Raspberry Pi takes over
Total Field of View
Flame Extinguishing (Mechanical)
• Compressed gas (CO2)
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Best option for large-scale fire - bonus points!
Portable Bicycle Tire CO2 Inflator Pump
Replaceable 16g CO2 cartridge
Extended nozzle at the front aligned with the sensors
Release
o Servomotor initializes to push the button of the tire inflator
• During the whole process
o Functions on the Pi and the thermal camera are always on
o Motion command from Pi is pulsed or ignored by the Arduino
Flame Extinguishing (Software)
• “Candle Scan”
o Creates array of all pixels over 60oC & locations
o Sets “Candle Detect” flag – initializes LED
• “Flame Align”
o Prompted by “Candle Detect” flag
o Determines which pixel is the hottest
o Calculates how far the robot needs to pivot in order to center on that pixel
• “Extinguish”
o Initializes the servomotor when CandleDetect == 1, MaxValue > 280o, and
-1 < ColumnTurn < 1
Flame Extinguishing (Software)
“Start Board”
• Contest requires:
o Sound activated start (microphone)
o Kill power plug
o Flame detect LED
• Microphone Circuit
o Buzzer frequency: 3.8 kHz ±16%
o Tried: Bandpass filter – bandwidth too large
o Decided: Frequency to voltage converter circuit
Questions?