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

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?ContentId=F43D8217-293D-480E-B657-54392CB1171A

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.

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

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

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

RoboSumo Push the other robot out of the Sumo ring

Specifications Junior Division Senior Division Sumo ring diameter   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 Robot type Any; Lego Mindstorms or NXT recommended. any

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

Unknown Problem in Robofest Sumo How to start is unknown Need sensor(s) Teams must bring a computer to program the unknown parts

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

Introduction to “SB2 (Sumo Bot 2)” Left motor: A Right motor: C Touch: 1 Light: 3 Ultra Sonic (distance): 4

Introduction to NXTG Programming Please go through Getting Started and Software Overview after this class

First NXT program: Go forward for 2 sec. and stop Let’s name the program first Click on Go >> button You’ll see a programming palette (canvas)

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

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

How to run your first program (1/2)

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)

How to rerun the program Check the program name on the LCD Press the orange button just once again

How to stop the program Gray button

First NXT Program: Go forward for 2 sec. and stop (Review)

Do not forget: Save your programs Meaningful file (program) names Use comments

2nd Program: ForwardBack Go Forward 2 rotations Wait 3 seconds, then Backward 1 rotation

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

Making Turns Turn left Spin left Face left stop Left wheel Right wheel

Turn90Left – Using a Motor Block! Forward 2 rotations, Turn Left 90 Degrees, and Forward 2 rotations

Forward 2 rotations, Turn Left 90 Degrees, and Forward 2 rotations – Turn90Left

How do we make to turn 90 degrees? Timer? Trial errors Let’s 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 23.55 / 17.27 = 1.3636 Travel distance needed: (14 x 2 x pi) / 4 = 21.98 cm Number of rotations needed? 21.98 / 17.27 = 1.2727 14 cm

How about 180 degree turns using a motor block? Forward 2 rotations, Turn Right 180 Degrees, and Forward 2 rotations 14 cm What is the rotation value for the Motor Block? 1.27 x 2

“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 Number of rotations needed? 21.98 / 17.27 = 1.2727

Spin180right

Class Challenge: A Simple Maze Start line box box Place a business card as a target point to reach

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