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
  Junior Division Senior Division
Sumo ring diameter 77 cm (30 inches) 122 cm (48 in)
Maximum robot mass 1kg (2.2 lbs) 2 kg (4.4 lbs)
Maximum robot width and length 23 cm (9 inches) 30 cm (11.75 inches)
Maximum robot height no limit 30 cm (11.75 inches)
Robot type Any Lego Mindstorms or NXT recommended. any
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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

1. Go Forward 2 rotations
2. Wait 3 seconds, then
3. 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