Building Mindstorms NXT Robots Dr. David Johnson School of Computing.
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Transcript of Building Mindstorms NXT Robots Dr. David Johnson School of Computing.
Building Mindstorms NXT Building Mindstorms NXT RobotsRobots
Dr. David JohnsonDr. David Johnson
School of ComputingSchool of Computing
What Is a Robot?What Is a Robot?
Resources for Learning About RobotsResources for Learning About Robots
• Web– Wikipedia
• http://en.wikipedia.org/wiki/Robot– New Scientist
• http://www.newscientist.com/article/dn9973-instant-expert-robots.html
– Youtube• Many!
– MAKE magazine– Boy Scout badge guide is quite nice and cheap
• Consider exercising your team’s FLL skills by having them look at some of these resources
Some Example RobotsSome Example Robots
• Big Dog– http://www.youtube.com/watch?v=b2bExqhhWRI
• Planetary Exploration– http://www.youtube.com/watch?v=nb2GsD7TAjU&feature=related
• Home assistance– http://www.youtube.com/watch?v=GTxW3GWZ5hI
• Hobby– http://www.youtube.com/watch?v=zX09WnGU6ZY
What Is a Robot?What Is a Robot?
• Sense– Update information about the world
• Plan– Modify original plan in response to this
sensed information
• Act– Move in the world or make a change in the
world
Mindstorms NXTMindstorms NXT
• Can it?– Sense– Plan– Act
Mindstorms NXTMindstorms NXT
• It can– Sense
• Light intensity and color• Sound intensity• Button presses• Distance to nearby objects• Wheel revolutions
– Plan– Act
Mindstorms NXTMindstorms NXT
• It can– Sense– Plan
• Small computer brain– “the brick”
• Graphical programming language
– Act
Mindstorms NXTMindstorms NXT
• It can– Sense– Plan– Act
• Three motors that turn
Goals For TodayGoals For Today
• Raise your comfort level with Mindstorms– Building– Programming– There is no substitute for doing it
• Try some common tasks– Wheeled robot– Respond to sensors
• Maybe a taste of competition…
Testing EquipmentTesting Equipment
• Plug in motors, sensors
• A critical thing to know is the view program– Let you read values from
sensors without writing a custom program
BuildingBuilding
• Not “normal” LEGO pieces– Based on the Lego Technic build system– Pegs and holes
• Can be frustrating– Stable
• One peg makes a rotary joint• Multiple pegs lock two pieces in place
– Strong• Keep in close to the main body• The wheel axes must not be wobbly and flex!
Building ResourcesBuilding Resources
• There are lots of instructions for building things online– http://www.nxtprograms.com/– Have the team try some out
• Learn things that work• Then modify
– Don’t get too distracted with NXT guitars, guns, etc.
– 5 minute bot• A quick base• Probably not good to adapt for
competition
ProgrammingProgramming
• Programming teaches– Breaking complex problems into solvable parts– Precise thinking and specification– Creative experimentation to discover and isolate
problems
• Programs are designed on a base computer– Downloaded by USB cable to the brick
•
Programming the BrickProgramming the Brick
• LEGO Mindstorms NXT– Default language for programming Mindstorms
• Designed to be friendly– Nice tutorials
• Try them with your team
– Not based on traditional programming languages– Easy to do very basic things
• More difficult to advance• It does have some subtle actions that can cause confusion
Learning to Use the TutorialLearning to Use the Tutorial
• Each tutorial is structured as– Challenge– Build– Program
• The mobile base from the tutorials is not my favorite– Takes too long to build– Difficult to modify
A Quick Programming Tour A Quick Programming Tour
• Control goes along the path
• Each block performs some action– Most blocks are very flexible– Learn the options at the bottom panel– Many actions continue until
• A sensor is triggered• Time has passed• A commanded result is finished
A Quick TestA Quick Test
• Attach a motor to the brick (ports A,B,C)• Attach a touch sensor to the brick (ports 1,2,3,4)• Write a program
– Move block• Set duration to unlimited
– Wait until touch– Move block
• Set the brakes
• Download to brick• Run it
Additional ResourcesAdditional Resources
• There is a lot to learn, but you can get started pretty quickly
• I recommend– Winning Design! LEGO Mindstorms NXT: Design
Patterns for Fun and Competition• Most FLL-centric of the books• Beginning to medium skill level
– If you don’t have prior experience, I think you would be foolish not to look at this book.
• Parts of my FLL camp notes– More for getting a novice team started
Let’s have a competition!Let’s have a competition!
• Go through maze• Stop before unknown finish “wall”
• How to solve?– Detect or dead reckoning
• Development cycle– Build, test, adjust, repeat– Most kids do not understand how to test and
modify something until it works
Teams!Teams!