An Autonomous Firefighting Robot

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An Autonomous Firefighting Robot
THE A.P.S. 3000

• Created by
• Jon Katz
  Chris Sokolowski
• -Sophomore -Sophomore
• -Mechanical Engineering -Chemical
  Engineering

Penn State Abington 04/24/2007 Engr 297H
Robotics Professor Avanzato
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Design Problem

• Our objective was to design, build, and program
  an autonomous robot capable of navigating through
  a multi-room maze, detecting a candle flame, and
  then extinguishing the flame.
• Compete in the Penn state firefighting
  competition.

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Robot Contest Rules

• Objective Find and extinguish candle in min.
  time.
• Max size 12.25 in. x 12.25 in.
• Robot must be fully autonomous.
• Any hardware/ software may be used.
• 1 Room Mode Candle is randomly positioned in 1
  room of the competitors choosing.
• Multi-Room Mode Candle is positioned randomly in
  one of four rooms selected at random.
• Flame Height 6 in. 8 in.
• Robot must extinguish candle from within 12 in.
  and cannot touch the candle.
• Candle will not be placed at the entrance to a
  room. It will be in a corner on top of a pie
  shaped white piece of paper that has a radius of
  12 in.
• Robot cannot look over, or climb walls.

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Maze Diagram
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Materials (Hardware)
The Legomindstorms NXT Kit (Hardware)
SERVO MOTORS
TOUCH Sensor
NXT Programmable Brick
Ultra-Sonic Sensor
SOUND Sensor
LIGHT Sensor
www.Lego.com
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Materials (Hardware Cont.)

• In the A.P.S. 3000, we utilized the following
• Sensors
• Light sensor (Downward pointing)
• Light sensor (Forward pointing)
• Rotational sensors (Built into the servo motors)
• Ultra-Sonic Sensor (Forward Facing)
• Sound Sensor
• Motors
• 2 Servo-motors- (Wheels)
• 1 High speed motor- (Fan)

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Materials (software)

• Legomindstorms NXT Kit (Software)
• Legomindstorms Education NXT

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Design Steps

• To build the basic mobile platform of the A.P.S.
  3000, we referenced the instructional book
  included with the NXT kit. We followed the step
  by step instructions until we had the basic
  platform assembled.
• We then chose and attached its various sensors
  based on the strategy we had developed for
  navigating through the maze and extinguishing the
  candle.

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Team Roles

• Chris
• Lead Hardware / Software Designer
• Tester / Problem Solver
• Jon
• Documentation Leader
• Tester / Problem Solver

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The A.P.S. 3000
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Mechanical Design

• Drive Mechanism Differential Drive system with
  pivot wheel.
• Advantage of this Drive System
• The Drive system of the A.P.S. 3000 isn't
  dependent upon gear ratios because its wheels
  are each directly connected to their own servo
  motor. We can adjust power levels of the left and
  right servo motors in the programming. One
  benefit of our particular drive system is that
  the servo motors have rotational sensors built
  into them.

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Mechanical Design (cont.)- Drive Mechanism
RUBBER WHEEL
PIVOT WHEEL
SERVO MOTOR (with rotational sensor)
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Mechanical Design (cont.)

• Forward Speed 9.0 in/sec
• Pivoting Speed 225.0 deg./sec
• Robot Dimensions
• Height 11 in.
• Length 9 in.
• Width 5.5 in.
• Wheels
• Rubber pneumatic wheels.
• Diameter 2 in.
• Width 1 in.

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Mechanical Design (Cont.)Sensors

• Light sensor (Downward pointing)
• Used to differentiate between carpeted/non-carpete
  d floor.
• This was needed because our robot was turning
  through different angles on the different
  surfaces. By detecting when the robot was on the
  carpet we could program the motors to operate at
  a different power intensity.
• Light sensor (Forward pointing)
• Used to detect the light intensity of the flame.

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Mechanical Design (cont.) Sensors

• Rotational sensors (Built into the servo motors)
• Used to accurately detect how far the robot
  traveled.
• After finding the number of rotations needed to
  get the robot to certain points, we programmed
  the robot to turn, stop, etc. when a certain
  number of rotations was detected.
• Ultra-Sonic (Sonar) Sensor (Forward Facing)
• Used to detect the distance of walls directly in
  front of the robot.
• Sound Sensor
• Used to detect a clapping sound that activated
  the robot and started the program sequence.

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Mechanical Design (cont.)- Sensors
Ultra-Sonic Sensor
Sound Sensor
Light Sensor (Candle)
Rotational Sensor
Light Sensor (Ground)
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Block Diagram of Actuators
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Block Diagram of Sensor Inputs
Sound Sensor
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Software AlgorithmTraveling to the room
Start when loud sound is detected.
Move forward 3 rotations
Routine A
Check surface light sensor
Run Routine A
Move forward until 9 inches from wall then stop
Low reflectivity
High reflectivity
Move forward until white line is detected then
stop
Carpet present
Carpet not present
Run Routine A
Move forward until 9 inches from wall then stop
Turn right 90(75 power)
Turn right 90(50 power)
End Routine A
Run Routine A
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Software AlgorithmExtinguishing the Candle
Turn left 45(75 power)
Turn right until high light level (candle) is
detected then stop
Wait 5 seconds then check ambient light value
Turn right until high light level (candle) is
detected then stop
Low Value
High Value
Candle re-ignited
Candle extinguished
Move forward one rotation
Turn on fan and run until low light level is
detected (candle extinguished)
LOOP
Turn on fan and run until low light level is
detected (candle extinguished)
Move forward until light sensor detects white
circle then stop
Turn left 45(75 power)
LOOP
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The A.P.S. 3000 In Action
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Performance Results
2nd Place!

• The A.P.S. 3000 won 2nd place in the
  firefighting competition!
• Robot competed in 1-Room mode for both trials
  successfully.
• Found and extinguished candle located in the
  middle room both times in a virtually identical
  fashion. Robot performed exactly as anticipated,
  and experienced no problems that hadnt been
  accounted for during our testing process.

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Future Improvements

• Increase speed of robot.
• This would reduce the time needed for the robot
  to find extinguish the candle. Allowing us to
  be more competitive with faster robots.

• Program robot to return to starting point.
• Adding this task to our programming would allow
  us to earn a higher score in the competition.
• Start robot and initiate the program with an
  electronic chirp, which meets the frequency
  specifications necessary to earn additional
  points.
• Program Robot to search multiple rooms, and
  possibly navigate around obstacles.

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Major Lessons Learned

• One of the most significant lessons that we have
  come away with is the importance of testing.
• Our robot performed its task successfully
  because of the thorough testing we performed. We
  recognized and accounted for obvious problems, as
  well as potential problems that we predicted.
• We realized just how much of the design process
  has to be dedicated to testing.

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Our Team
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Our Research Project- Find the Baby

• We chose the Find the Baby option for our
  research project.
• This task is similar to the firefighting
  competition, except we are searching the maze for
  a baby doll.
• We locate the baby by detecting the light
  intensity of 2 L.E.D.s mounted to the left and
  right of the baby on the platform it sits on.
• We redesigned our robot for this project,
  including blinking siren lights and sounds.

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Find the Baby
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References

• Penn State Abington Website
• http//www.abington.psu.edu/psasite.php
• Trinity College Contest Website
• http//www.trincoll.edu/events/robot/