Lego Robotics Course Outline

Weston Middle School, Weston, Massachusetts

1. Supplies and Materials

2. Organizing and Storing Parts

3.Setting Up Groups- Students work with a partner on all assignments. For final project, two groups may work in coodination if two robots are produced which interact, using IR communication or other means.

4. Glossary

5. References:

• Building
• Programming

Instructors: Jonathan Dietz/ Margaret Burns

Mr. Dietz may be contacted at (781) 529-8060 x 6142 or at dietzj@mail.weston.org

Mrs. Burns may contacted at (781) 529-8060 x 6144 or at burnsm@mail.weston.org

1-2

• The Lego Mindstorm System is a robot prototyping development system. It includes structural pieces, sensors, motors, and the RCX microcomputer
• Lego pieces can be sorted into broad group categories ( Bricks, Plates, Beams, Axles, Connectors, Wheels, Gears) and specialty parts
• Locking structures together with vertical beams and pins greatly strengthens structures
• Technology means knowledge of techniques( methods of construction)
• Gear Trains-permit mechanical advantages in speed or torque to be created, but not both;
• Gears can be used to change the axis of rotation.
• There is always a trade-off
• Torque= Force x Radius; hence for a motor with a given torque, the larger the radius of the wheel, the less (forward) force.
• In the design process, results are analyzed and use to improve the designs.
• A crank is an example of a mechanism that changes rotary motion into back-and-forth motion

• The one-motor car-Chain of energy:
  • Hydrogen fusion in sun
  • Fusion produces radiation
  • Radiation absorbed by chlorophyll in plants
  • Photosynthesis stores energy in the carbon bonds of sugar in plants
  • Plants eaten by humans
  • Respiration extracts energy from sugar, producing ATP
  • ATP powers muscle contraction
  • Muscles rotate coil in the magnetic field of the Lego motor, producing electricity
  • Electricity creates magnetic field in coil of motor, producing motion by magnetic repulsion against stator magnets

Getting acquainted with the pieces: Messing around

Set up Teams: 2 students per team

• Lesson Plan #1 -Introduction
• Lesson Plan #2 -Sorting Challenge
• Lesson #3A-3B-3C -Simple Car Challenge
• Lesson 3D: One-Motor Vehicle-Part 1
• Lesson #4 -Gears and Claw Challenge(s)
• Jesse Sullivan with Bionic Arm
• Rylee with Myoelectric Arm

Technology Mini-Lecture: Bioengineering, Orthotics and ProstheticsQuiz 1: Hardware pieces

Biology Connection: Just as, using the Lego instruction sheets, a multitude of different robots doing different functions can be built with a limited 'toolkit' of Lego parts, so living things can build an infinite number of self-assembling nanobots- proteins- using a basic tookit of 20 amino acids, following the instructions found in DNA.

2

• Engineers start with proven designs( such as the Tankbot), then improve or elaborate upon them
• The RCX(Robotic Command Explorer)is a self-contained microcomputer
• The RCX’s have 3 input ports, 3 output ports, as well as a display screen and buttons.

• Input devices include touch sensors, light sensors and angle sensors; these attach to ports 1,2 and 3
  • Human Light Sensor: The Eye
  • Human Touch Sensor: Pacnian Corpuscle
• Output devices include motors and lamps; these attach to ports A, B, and C

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• Robolab is an icon-based programming system. Programs are created on the PCs, and then downloaded through the infra-red towers to the RCX microcomputers.
• The RCX’s must be loaded with a firmware program to be able to run Robolab programs.

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• In Robolab Pilot , you can program sequential programs with one or more steps. Each step has an action( i.e. Motor A forward) and a condition(i.e., Wait for 4 seconds). Music can be added in Pilot using Piano Player.

Introduction to the RCX

Show RCX Setup Video; load firmware; -Explore Built-in Programs: Programs 1, 2 and 3; Using Program 1 to test hardware

Tankbot Challenge

Extra Credit: Build Actuator Assembly or Driving Base Chassis

MCAS Mini-Lecture: Communication Channels

Pilot 2 and Pilot 3 Training Missions

-Pilot 2 Challenge: Up and Back

-Pilot 3 Challenge: Follow a Square

• Robotic Navigation by Dead Reckoning

-Quiz 2: RCX, inputs, outputs

Pilot 4 Challenge: The Light at the end of the tunnel

Pilot 4 Challenge: Fan-Tastic

3

• In Robolab Inventor, there are a tools palette, a functions palette, and a work area.
• Function icons are arranged, edited, and ‘wired’ using the various tools, then downloaded to the RCX.
• Programs must be saved in the user’s own server file; you must login under your own password.
• Inventor 1&2 uses basic motor, timer, and sensor icons to control a robot’s behavior. Jump and Land can be used to make a program repeat.
  
• The first step in writing a program is to graphically block out the moves and responses of the robot in a diagram. Next, write down the algorithm, describing in ordinary language what the robot does. Finally , convert the algorithm to Robolab code
• Label the program with comments giving the algorithm
• .Use the alert beeps to dynamically debug
• Introduction to Piano Player
  

Algorithms

Introduction to Inventor

Inv 2 Challenge: Sumo-Bot

-Demonstrate programming techniques

Challenge: Peak Performance

Gear Trains

Quiz 3: Inventor 1 &2

4

• Programming structures permit robots to have complex behaviors.
• Split tasks permit robots to do two things at the same time.
• Loops permit robots to repeat behaviors for a set number of times or while a condition exists.
• Fork/Merges enable robots to do one of two things depending on a condition; combined with a jump and land, it permits continual monitoring of an input(a feedback loop).
• Much of our body is governed by feedback loops controlled by the autonomic nervous system
  • Iris changes size to let in more or less light to eye
  • Heart Rate/Breathing regulated to maintain constant oxygen level
  • Sweating/shivering/blood vessel dilation and constriction regulate body temperature
  • Water reabsorption in kidneys related to maintain constant salt concentration in blood

Inv 3 Challenge: Split Task

Inv 3 Challenge: Line Follower

Musical Sumo-Bot

Loops Challenges

MCAS Mini-Lecture: The System Model and Feedback Loops

Biology Connection: Homeostasis Slides

5

• Basic mechanical mechanisms include:
• Rack and Pinion-changes rotary motion to back-and-forth- should use rotation sensors to limit travel
• Cam – Changes rotary motion to up and down- useful for making jaws open and close
• Linkages- Change direction and speed of movement
• Caster Wheels; rack-and-pinion steering; micro motors; crown-and-spur gears;

By using infra-Red or Bluetooth Mail, robots can communicate with each other to do more complex functions than possible individually.

• Video Clip: Sociable Robotics and James McLurkin

• Video Clips: Swarms

Handshaking is an engineering term for when a machine sends out a message, and its audience acknowledges its receipt.

Advanced Programming structures include:

• Events- permit sensor to break an endless loop;
• Containers- Permit manipulation of variables
• Mail- Permit sending of messages between RCX’s. Can use either mail functions or fill remote container functions.

Cam Challenge: Open Wide

Rack and Pinion Challenge

Mail Exercises:

• Intro Exercise(Robolab)
• Handshaking (Robolab)
• Follow-the-leader challenge-Fred and Ginger

Linkage Challenge
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Events Challenge- Light-controlled SumoBot

Containers Challenge: Soak the Teacher

6

Review of Concepts

Sociable Robots: The Work of Cynthia Breazeal

Cynthia's Homepage

Military Robots: The Talon Robot (Foster-Miller)

• Sensors
• Controls
• Operation

Mars Exploration: Karl Iagnemma

Intro to Final Project-

Project Milestones and Grading:

Proposal: -10%
Software Flowchart/Algorithm: -10%
Four(4) Design Journal Entries- 10%
Printout of Computer Program -10%
Functioning Project -40%
Final Report or Web Page: -10%
Presentation/Demonstration: -10%

The Design Process
Tips and Tricks

Write Proposal for final project

Themes: Spooky World; Robotic Zoo; Amusement Part

7

Review Advanced Programming and Mechanisms:

• Events- permit sensor to break an endless loop;
• Containers- Permit manipulation of variables
• Mail- Permit sending of messages between RCX’s
• Angle Sensor & Rack and Pinion: Making a tongue go in and out
  

8

9

Final Report
Presentation

MCAS Mini-Lecture: The Design Process

Background Material

• The Having of Wonderful Ideas, by Eleanor Duckworth

Websites:

• Build-It-Yourself Constructopedia
• Lego Education
• City University of New York Lego Curriculum
• Columbia University MS Lego Curriculum

Revised 8/24/05 J. Dietz