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

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

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

4. 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

5. Mini Sumo Competition With Unknown Problem:
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

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

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

8. Using a random number for Move duration

9. 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!!!

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

11. 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

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

13. 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

14. 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

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

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

17. Height of the robot matters?
Consider the “center of gravity”

18. 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

19. 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 ( competition date at your school

20. 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)