Introduction to LEGO NXT robotics and Robot Sumo

Introduction to LEGO NXT robotics and Robot Sumo Workshop Day 3 CJ Chung Associate Professor of Computer Science Lawrence Technological University

Workshop Third Day Improved Sumo program ¡ Mini Competition ¡ Tips and Ideas to improve your Robot! ¡ Advanced Topics in NXTG (optional) ¡ Team Pictures ¡ Planning ¡

Review: Basic Sumo ¡ Repeat the following forever: l l l ¡ Go forward until the edge Backward slightly (in Big block) Turn right Problems? l Touch sensor and Ultrasonic sensor were not used

Improving the Sumo program Introduce a parallel sequence beam for touch sensor– whenever the bumper is hit, change the direction ¡ Introduce a parallel sequence beam for US sensor– whenever it detects an close object, go straight using full power ¡ ¡ Introduce a random wait value for turning

Mini Sumo Competition ¡ With Unknown Problem: l l The robot must wait until touch sensor is pressed Wait 5 seconds, then start to move Team 1 Team 2 Team 3 Team 4 Team 5 X X X X

Team Picture The team picture will be printed on your personal certificate ¡ Please submit the following for each team: ¡ l l Team name member first and last name member grade member gender

Program for the Mini Competition Press “Shift” to connect parallel sequence beams

Using a random number for Move duration

Is this a perfect program? No, there are still some problems ¡ One example: • The robot detects the edge line. ¡ • Move backward. • Turn right around 90 degrees. • Then the robot must see the outside of the ring which is very dark!!!

Ideas to improve your Sumo. Bot Improve (debug) your program! ¡ Applying Theories learned in Physical Science ¡ l l l ¡ Mass, Newton’s laws Friction Gearing Wheel size Power level Detecting the opponent (can be done later) l l Touch sensor US sensor(s)

Ideas to increase weight of your Robot What is the max weight of each division? ¡ Add more Lego technic pieces, if you have some at home ¡ Add Coins, Used Batteries, or others – make a holder using cardboards ¡ ¡ Put your team name on the robot. An idea: make a team flag

Ideas to increase friction of your Robot Use rubber bands ¡ Add more wheels later for Worlds ¡

Gearing Ideas Use gear train to increase gear ratio ¡ Considering resources, this is not allowed for the school qualifier ¡ The winner from the school qualifier may consider this idea later ¡

Changing Wheels? Using bigger wheels ¡ Considering resources, this is not allowed for the school qualifier ¡ The winner from the school qualifier may consider this idea later ¡

Make sure the Power! Default power level is 75% ¡ Fully charge your battery!!! ¡ How to check the voltage level? ¡ l See the icon on the LCD

Changing the shape of the Robot Make it sturdy ¡ Front part may need some changes (After the school qualifier) ¡

Height of the robot matters? ¡ Consider the “center of gravity”

Ideas using 2 Touch Sensors A touch sensor –front left Another touch sensor – front right If left sensor is pressed – turn left and push hard ¡ If right sensor is pressed – turn right and push hard ¡ If both left and right sensors are pressed, push straight hard ¡

What is next? - Meet with your teacher at least twice before the school qualifier Improve your programs ¡ Add stuff for the max possible weight for your robot ¡ Review what you have learned for the unknown problem. If you do not solve the unknown problem, you lose automatically ¡ Signed Media Release form must be ready before the qualifying Robofest (www. robofest. net) competition date at your school ¡

Note on “Switch” This 3 day workshop material did not cover “Switch” block that is an important part of programming ¡ The sample sumo program using parallel sequence beams can be rewritten using switches (data-driven fashion) ¡