Silly Walks

ACTIVITY HEADER

 

 

 

Name of Activity Silly Walks
Author Laura Fradin, Jake Hellman
Keywords NXT, robotics, brick programming, 5th grade, aguayo, wheels, programming. JQS
Subject NXTs
Grade Level 5
Time 1 Hour Total
Brief Description Build and Program a robot that uses something other than wheels to move.
Lesson Objectives: -Understand brick programming
-practice building with NXT kits/pieces
-using non-traditional ways to make the robot move (NO CARS!)
Materials Needed: -NXT kits
-projector (to demonstrate on brick programming and show example video)
Preparation and Set Up: Show kids a video that has examples of Silly (https://nxt.dreschallenges.com/?p=2145)
Procedure 1) Show kids how to attach the motors to the brick. Explain that the motors must be attached tot eh brick in order for the whole thing to move. 2) Demonstrate how to program the robot to go forward (turn it on, NXT program, forward, empty, forward, empty, stop/loop). Make sure each student does this and that their motors work. Explain that it is the ORANGE part of the motor that moves to make sure that things are attached to that. 3) Hand out kits. 4) Allow students to build and test as they build. Help students as needed. 5) Present at the end of class
Extensions: -use more or less motors
-make the robot walk in a way that mimics a real animal
Reference 1 http://sites.tufts.edu/stompactivitydatabase/files/formidable/SillyWalksOutline.pdf

NXT Segway

ACTIVITY HEADER

 

 

 

Name of Activity NXT Segway
Author Jay Clark
Keywords NXT, balance, wheels, sensors, wiring, math blocks, proportional controllers, light sensor
Subject NXTs
Grade Level 9+
Time 3 Hours Total
Brief Description Students build and program an NXT to balance on only two wheels using two light sensors.
Lesson Objectives: Master the use of wiring and math blocks
Master Building with NXT pieces
Introduce the concept of proportional controllers
Materials Needed: NXT kit plus one additional light sensor for each group.
Computers with LEGO Mindstorms installed.
Preparation and Set Up: Make sure this activity is done in an evenly lit room with a consistently-colored floor. Otherwise, it will not work.
Distribute extra light sensors to each group.
Necessary Background An NXT segway works by separating two light sensors about the center of gravity of the robot. If the robot loses its balance and starts to lean one way, one light sensor will receive more reflected light than the other. The differnce in these values can be scaled and then used to control the motors.

Generally, the following tips allow for the easiest construction of an NXT Segway:

The robot’s center of gravity should be such that the robot’s balancing point allows for the two light sensors to be evenly spaced off the ground.
The further the light sensors are from the robot, the more sensitive the response.
Weight should be added way above the pivot point (the wheels). Think about balancing a broom vs. balancing a watermelon.

Vocabulary: Proportional Controller – Control in which the amount of corrective action is proportional to the amount of error

Procedure Introduce students to the concept of proportional control. examples:

  • slowing down based on distance from stop sign
  • changing dial in shower based on error from desired temperature.

Introduce proportional control in the human brain in the form of keeping balance.

  • If you lean forward a little bit, your brain applies pressure to your toes to try to push your center of gravity back.
  • If you move to far forward, your brain will step forward.
  • If you are leaning way far forward, your brain will call for a very quick, large step.

The reaction is proportional to the error.   Introduce the segway activity. Now that we know how to balance an object that we know is leaning one way or another, we need to determine how we can figure out if the NXT is leaning. Ask students for suggestions. Encourage all ideas, but in the end, tell them that we’re going to use light sensors because they have the most consistent response and resolution. Activity If we mount the light sensors so they are the exact same distance off the ground when the robot is balanced, we can be sure that the light sensors will have the same reading. If the robot starts leaning, there will be a difference in the light sensor readings. We can use that difference to control the motors to balance the robot.Notes Students will have to experimentally determine their constant of proportionality. Because the power input of the move block converts negative numbers into positive numbers, there needs to be a comparison block to set the move block’s direction.

Reference 1 http://sites.tufts.edu/stompactivitydatabase/files/formidable/a3.png
Reference 2 http://sites.tufts.edu/stompactivitydatabase/files/formidable/b4.png

Ramp Cars: Wheel and Axle

ACTIVITY HEADER

 

 

 

Name of Activity Ramp Cars: Wheel and Axle
Author Kelly Clark
Keywords ramp, cars, beams, axles, bushings, wheels, Simple Machines, Potential Energy, Kinetic Energy, friction
Subject Simple Machines
Grade Level K, 1, 2, 3, 4, 5, 6
Time 1 Hour Total
Brief Description Using LEGOs, students will build a car to travel the farthest distance off a ramp.
Lesson Objectives: - To learn about wheels and axles.
- To introduce potential and kinetic energy.
Materials Needed: - LEGO Simple Machine kits or homemade kits with lots of beams, axles, bushings
and wheels.
- Ramp.
- Recording sheet.
- ‘Ramp Cars’ Worksheet.
Preparation and Set Up: - Set up a testing ramp.
– Mark starting point on ramp to start cars.
– Mark the spot at the bottom of the ramp that students will measure distance traveled from.
- Make one copy of the ‘Ramp Cars’ worksheet for each student.

- Arrange students in pairs.
- Distribute materials.
Necessary Background This activity explores the concepts of kinetic and potential energy. A car moving down a slope converts potential energy into kinetic energy. Potential energy is the amount of stored energy the car has when it is sitting at the top of the ramp. As the car moves down the ramp it converts potential energy into kinetic energy – the energy of movement of the car. At the bottom of the ramp the car has converted all the potential energy to kinetic energy. The point just at the bottom of the ramp is the point at which the car has its maximum kinetic energy. The car will slow at the bottom of the ramp due to loss of energy to the floor through friction – the force between the car tires and the ground.

Vocabulary:
Wheel
Axle
Simple machine
Potential energy
Kinetic energy
Friction

Procedure
  1. Tell student that they the design challenge is to build a car that will travel down a ramp and then travel the farthest horizontal distance from the bottom of the ramp.
    1. Tell students about potential energy. The energy that the car has at the top of the ramp before it is released (stored energy). This energy is converted into kinetic energy (the energy of the movement of the car has while moving).
      1. Explain that potential energy is highest at the top of the ramp (explain this by telling students that the car has the ‘potential’ to travel the farthest when it is placed here vs. when it is placed lower on the ramp). Potential energy is affected by gravity and the mass of the car.
      2. Explain that the kinetic energy is highest when the car is just at the bottom of the ramp because this is when it is moving the fastest, but has no more potential energy from being on the ramp.
      3. Explain that the force of friction – the force of the ground on the tires – is what slows the car down when it reaches the bottom of the ramp. Without friction, the car would continue to go forever in the same direction at the same speed.
    2. Tell student that they can build their car however they would like using the material provided. They can change the number of wheels, type of wheels, axles, etc. Remind them to think about potential energy, kinetic energy, and the forces of friction
  2. Have students build and test their cars. Allow each group three tests and record the farthest trial on the board or on a sheet.
  3. Have the students fill out the ‘Ramp Car’ Worksheet.
  4. Bring the class together to discuss the activity.
    1. Talk about what would be different if the ramp was shallower, steeper, rougher, or smoother. Do a demonstration if possible. Use this demo to discuss inclined planes.
    2. Discuss the different designs. Whose car went the farthest? What was different about this design? What did some of the other designs look like and why did they not go as far?
    3. Conclude by asking students how they might improve their designs.
Extensions or Modifications: You can modify this activity to be applicable to older grades by having student graph distance v. time, taking the mass of their cars and predicting how far their car will travel using mathematics.
Reference 1 http://sites.tufts.edu/stompactivitydatabase/files/formidable/ramp1.doc
Reference 2 http://sites.tufts.edu/stompactivitydatabase/files/formidable/ramp2.pdf
Reference 3 http://sites.tufts.edu/stompactivitydatabase/files/formidable/ramp3.pdf

Build a Sturdy Vehicle

ACTIVITY HEADER

 

 

 

Name of Activity Build a Sturdy Vehicle
Author STOMP
Keywords sturdy, vehicle, drive, motors, pulleys, Simple Machines, Engineering Design Process, ramp climbing, wheels
Subject Simple Machines
Grade Level K, 1, 2, 3
Time 1 Hour Total
Brief Description Students will build a vehicle that is sturdy and able to drive using motors.
Lesson Objectives: - Introduce students to building vehicles using prior knowledge of sturdy building, motors and pulleys.
- Use the Engineering Design Process to accomplish the task.
- Explore pulley combinations that facilitate ramp climbing (extension).
Materials Needed: - LEGO Simple Machine kits.
- Makeshift ramp (board and stack of books, poster board, wooden blocks, etc.).
- Extra Batteries.
- ‘Engineer’s Planning Sheet’.

- ‘Engineer’s Final Report’ Worksheet.
Preparation and Set Up: - Set up a ramp.
- Make enough copies of worksheets for the class.

- Arrange students in pairs.

- Distribute LEGO Simple Machines kits.

Necessary Background Vocabulary:
Pieces-
Motor
Wire
Battery pack
Wheels
Hubs
Procedure Procedure:

  1. Review how to connect the LEGO motor, wire, and battery pack and how to make the motor run backwards and forwards.
  2. Review Sturdy Building and pulleys. Talk about how to make the motor attach to the wheels through pulleys.
  3. Introduce the design challenge using the Engineering Design Process
    1. Identify Problem: Tell students that their LEGO people needs a sturdy vehicles to transport them from place to place (over hills and mountains if doing ramp extension).
    2. Research: Think about what students have done before and how it might help with this design challenge. Research what diifferent types of cars look like, how they act, and what there purpose is (three wheels v. four wheels, front-wheel-drive v. rear-wheel drive, Large trucks v. small cars). Talk about different ways to power a car (gas, electric, hybrid, hydrogen etc.)
    3. Brainstorm: Talk about how you might make a frame for a vehcile. Talk about attaching the motor to make the wheels move (and that it does not have to be attached to every wheel for the car to move). Discuss how to make the design sturdy.
    4. Choose and Plan: Have students fill out the ‘Engineer’s Planning Sheet’. Have each student circle the part they will build.
    5. Create: Have students build their cars.
    6. Test: Students must pass two tests
      1. Drop Test - The vehicle cannot break when dropped from the ankle.
      2. Drive Test - The vehicle must move using the motor and battery pack.
    7. Redesign: Have students rebuild after failed tests. Have them identify problems their cars may be having.
    8. Share: 
      1. Have students fill out ‘Engineer’s Final Report’
      2. Come together as a class and let each student show off their design.
      3. Talk about difficulties the students encountered and how they solved their problems.
Extensions or Modifications: - Have students use different sized pulley wheels to make their car drive up a ramp
without tipping back or falling off (smallest possible pulley on the motor, largest on
the axle with wheels). You will need to add the Ramp Test – the car should drive
to the top of the ramp. Students may need to add additional weight to their cars.

- Have students construct a cart that their car can pull. Have this cart pull something
(books, blocks, LEGO people, LEGO trash/brush/bricks).

- ADVANCED: Have students build a car that pulls a car up a ramp.

Modifications:
- Make rules about where the designs can be tested.
- Have a chart for who has completed what tests.

Reference 1 http://sites.tufts.edu/stompactivitydatabase/files/formidable/car1.jpg
Reference 2 http://sites.tufts.edu/stompactivitydatabase/files/formidable/car2.jpg
Reference 3 http://sites.tufts.edu/stompactivitydatabase/files/formidable/car3.pdf

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