Introduction to LEGO NXT robotics and Robot Sumo for

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Introduction to LEGO NXT robotics and Robot Sumo
for
CJ Chung Associate Professor of Computer Science
Founder and Director of Robofest Lawrence
Technological University
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This program is possible thanks to

• a grant from Detroit Auto Dealers Association
  (DADA) Charitable Foundation Fund,
• which is a fund of the Community Foundation for
  Southeast Michigan.
• For more details, check out a press release at
• http//www.ltu.edu/news/detail.asp?ContentIdF43D
  8217-293D-480E-B657-54392CB1171A

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Schedule

• First Workshop Day (3 hours)
• Second Workshop Day (3 hours)
• Third Workshop Day (2 hours)
• Meetings with your school staff/teachers to
  improve your sumoBot (3 hours x 2 meetings
  suggested)
• Official Competition at your school to select one
  team to advance to the World Robofest
  Championship on April 26. General public to be
  invited.

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Workshop First Day (3 hours)

• Introduction to Robotics
• Introduction to Robofest and Robot Sumo
• Introduction to Lego NXT
• Introduction to NXTG
• Basic programs
• Motors
• Wait
• Turns

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Introduction to Robotics

• What is a true robot?
• autonomous robot with an on board computer
• Mechanical, electrical, and computational
  components
• Six fundamental components of a robot
• A brain or brains computer
• Body physical chasses that holds other pieces
• Actuators motors, hydraulic pistons, pneumatics
• Sensors
• Power sources
• Communication mechanism

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What is Robofest?

• 100 Autonomous
• Affordable
• Challenging Unknown problem
• No direct adult help allowed during the
  competition
• Qualifiers and a World Championship
• Various categories including Robot Sumo
• Two divisions
• 5th 9th grade Jr. Division
• 9th 12th grade Sr. Division

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RoboSumo
Push the other robot out of the Sumo ring
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Specifications
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Why Sumo?

• The most popular robot competition in the world
• Integrator in Science Education Math, Logic,
  Computers, Mechanics, and Physics
• Good for rookie teams
• Fun Motivator

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Unknown Problem in Robofest Sumo

• How to start is unknown
• Need sensor(s)
• Teams must bring a computer to program the
  unknown parts

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Introduction to Lego NXT

• Brain RCX micro computer
• Body Lego Technic pieces
• Actuators up to 3 motors
• Sensors Light, touch, US, Sound, etc.
• Power source 9V (six AA batteries or
  rechargeable battery pack)
• Communication mechanism USB or Blue Tooth

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Introduction to SB2 (Sumo Bot 2)

• Left motor A
• Right motor C
• Touch 1
• Light 3
• Ultra Sonic (distance) 4

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Introduction to NXTG Programming

• Please go through Getting Started and Software
  Overview after this class

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First NXT program Go forward for 2 sec. and stop

• Lets name the program first
• Click on Go gtgt button
• Youll see a programming palette (canvas)

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First NXT program using SB1 Go forward for 2
sec. and stop (2/3)

• Click on Move button
• Drag and drop the move block to the canvas

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First NXT program using SB2 Go forward for 2
sec. and stop (3/3)

• Change parameters for the Move
• Port
• Direction
• Steering
• Power
• Duration
• Next Action

Block
Configuration Panel
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How to run your first program (1/2)
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How to run your 1st program (2/2)

• If Found New Hardware pops up, just follow the
  instruction
• Click on Download button
• Recommended to un-plug the cable from the Bot
• Press the orange button 4 times (Turn on, My
  files, Software files, Run your program entitled
  go2stop)

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How to rerun the program

• Check the program name on the LCD
• Press the orange button just once again

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How to stop the program

• Gray button

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First NXT Program Go forward for 2 sec. and stop
(Review)
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Do not forget

• Save your programs
• Meaningful file (program) names
• Use comments

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2nd Program ForwardBack

• Go Forward 2 rotations
• Wait 3 seconds, then
• Backward 1 rotation

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Go Forward 2 rotations, Wait 3 seconds then
Backward 1 rotation ForwardBack
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Making Turns

• Turn left
• Spin left
• Face left

stop
Left wheel
Right wheel
Left wheel
Right wheel
stop
Left wheel
Right wheel
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Turn90Left Using a Motor Block!

• Forward 2 rotations,
• Turn Left 90 Degrees,
• and Forward 2 rotations

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Forward 2 rotations, Turn Left 90 Degrees, and
Forward 2 rotations Turn90Left
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How do we make to turn 90 degrees?

• Timer?
• Trial errors
• Lets do the math!!!
• Width of the robot 14 cm
• Diameter of the wheel 5.5 cm
• Perimeter of the wheel 5.5 cm x pi 17.27

Travel distance needed (14 x 2 x pi) / 4
21.98 cm
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How about 180 degree turns using a motor block?

• Forward 2 rotations,
• Turn Right 180 Degrees,
• and Forward 2 rotations

What is the rotation value for the Motor Block?
1.27 x 2
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Spin 180 degrees using Move/Steering

• Forward 1 rotation,
• Spin right 180 degrees
• Forward 1 rotation

Travel distance needed (14 x pi) / 2 21.98 cm
14 cm
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Spin180right
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Class Challenge A Simple Maze
Start line
box
box
Place a business card as a target point to reach
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Online Resources

• www.ortop.org/NXT_Tutorial a great tutorial on
  how to program in NXTG
• nxtasy.org with more information than you could
  ever want about LEGO robots and programming a
  great place to ask questions