TEAM MECHAZAWA

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TEAM MECHAZAWA
Jeong Bang Riley Ceria Grant Higa
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Job Duties
Jeong
Riley
Grant

• Chassis Design and Fabrication
• Program Algorithms

• Head Programmer

• Chassis
• Circuit design
• Assistant programmer

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Micromouse

• Autonomouse robot that solves a maze in the
  fastest time possible.
• International
• Many different types of mice.
• Great Fun!!

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Our Mouse
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Our Mouse

• Side Sensors (Distance Sensors)
• Stepper Motors
• Rabbit Processor
• Nice Wheels
• Cool Chips a lot of SMD.
• SUPER SMALL!!

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Side Sensors

• Analog signal
• A/D converter
• 5 bit accuracy
• Requires calibration
• More distance information
• Smoother tracking

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Analog to Digital Mux
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Sensor Placement

• 4 sensors-total
• 2 front-facing
• 2 side-facing

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Chassis Considerations

• Placement of components
• Sensors
• Motors
• PC boards
• Batteries
• Heat
• Symmetry
• Weight

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Limited Tools

• Bandsaw was missing teeth
• Used clamps to bend brackets
• Dremel was the main tool used
• Parts mysteriously disappeared

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Resulting Chassis

• Buddy-esque shape
• One piece design
• Brackets hold sensors
• Standoffs hold Circuit Boards
• Furniture slider support

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Chassis Problems/Solutions

• Motor axle to long
• Choose different motors
• Sensor angles
• Find a better way to mount sensors

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Circuit Design (power)

• 8 AA NiMH batteries
• 2100 mAh
• Power
• 12V DC-DC step up converter
• MAX1771
• Possibly unnecessary
• 5V linear regulator
• LM340
• Runs hot

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Circuit design (driver)

• Driver Board
• Panasonic 2SK2211 n-MOSFET
• Runs fairly cool
• Small size
• Gate storing too much charge
• Added resistor to increase response

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Circuit design

• Main board
• 5V regulator
• Rabbit RCM2000
• MAX118 A/D converter
• SHARP GP2D120 distance sensors

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PCBoards

• Design done in CIRCAD
• Double and single sided
• Iron-on resist paper
• Difficult to iron on well
• Ran out of etchant

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Programming

• Tracking
• Staying in Center
• Mapping Walls
• Solving
• Find Center
• Fastest Path
• Speed Run

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Centering

• Reading Analog Signals
• Delays
• Blind Tracking
• Front Wall

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Mapping

• Setting Values
• Pointers or no pointers?
• Wall There?
• When to check?

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Finding Center

• Flood fill
• Simple

• void flood(int floodx, int floody, int notbegin)
• int x, y // state position variables for
  flooding
• int hd_value // highest defined value while
  flooding maze
• int stopflood
• int mox, moy
• int decided // states whether a new direction
  has been decided
• int turn // states which way tpo turn
• decided FALSE // no new direction decided in
  begining
• turn STRAIGHT // want to go straight first
• mox mx
• moy my
• // initially floods maze giving all values high
• for(x1 xlt17 x)
• for(y1 ylt17 y)

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Fastest Path

• Searches of finding Center
• Floods from Center to Beginning
• Goes to unsearched Cells

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Speed Run

• The Grant Delay
• Acceleration
• Faster
• No mapping, or solving
• followpathx array

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Tracking Problems

• Sensors
• A to D conversion
• Motor limits
• Tracking of an imaginary wall
• Jittery
• Step Counts
• False Wall Readings

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Tracking Solutions

• Play with wires
• Use 5 bit accuracy
• Created new type of Delay
• Limited distance for walls

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Solving Problems

• POINTERS!!!!!
• Arrays
• Loopsgoing on and on
• Stopping at each cell

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Solving Solutions

• Make sure the are everywherefixed almost
  everything
• Only Solve at Junctions

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Problems

• Board Fabrication
• Poor PCBoard design
• Lack of sufficient etchant
• Chassis
• Lack of tools
• Sensor attachment
• Battery placement

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Problems

• Connectors
• Motors
• torque
• width
• Programming
• Time

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Initial Goals

• Build a working mouse and win regions
• Do 45s
• Be able to compete on the international level at
  some point in the future

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Results

• Mouse can find the center and take the shortest
  explored path
• Too wide for 45s
• Too slow to compete internationally
• Mouse is ghetto
• Sensor connecters may fail