Introduction to LEGO NXT robotics and Robot Sumo

Workshop Day 3

CJ ChungAssociate Professor of Computer ScienceLawrence 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: Go forward until the edge Backward slightly (in Big block) Turn right

Problems? 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: 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

Team 1 X X X X X

Team 2 X X X X

Team 3 X X X

Team 4 X X

Team 5 X

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

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 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)

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?

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 leftAnother 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)