+ All about Electric Motors Building a Robot Arm Christopher Lester Yvonne Pelham Douglas Gorham Kapil Dandekar TISP: Montreal 15 – 16 May 2009
Mar 27, 2015
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All about Electric Motors
Building a Robot Arm
Christopher Lester
Yvonne PelhamDouglas GorhamKapil Dandekar
TISP: Montreal15 – 16 May 2009
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Christopher LesterIEEE Educational Activities
Exercise 1:
ElectricMotors
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+All About Electric Motors
Learn basic theory of electric motors
Learn basic theory of electro-magnetic forces
Apply theory to everyday uses of electric motors
Build a working model of an electric motor
Objectives for Students
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+All About Electric Motors
Physical Science: Develop an understanding of motion and forces,
transfer of energy Develop an understanding of the interactions
between energy and matter
Problem Solving: Develop an understanding of the role of
troubleshooting, research and development, invention and innovation, and experimentation in problem solving
Principles & Standards for School Mathematics – 1
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+All About Electric Motors
Personal and Social Perspectives: Learn about science and technology in society and
through history Develop an understanding of the risks and
benefits of technology Understand the abilities of science and technology
Principles & Standards for School Mathematics – 2
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+All About Electric Motors
Nearly every mechanical motion you interact with everyday is run by either a DC or AC electric motor
Motors are everywhere!
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+All About Electric MotorsParts of the Electric Motor
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6 Main Parts
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North pole of magnetic field and armature repel each other
South pole of magnetic field and armature repel each other
Torque is generated in clockwise direction
All About Electric MotorsOperation of the Motor
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Motor shaft rotates clockwise
Torque continues to be generated in the clockwise direction
All About Electric MotorsOperation of the Motor
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Armature poles reach the point where they are the furthest away from the same magnetic field.
Rotational inertia keeps motor shaft moving until brushes swap sides of the armature
All About Electric MotorsOperation of the Motor
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The brushes have moved to the opposite sides of the commutator: The south pole of the
armature now becomes the north pole
The north pole of the armature now becomes the south pole
The cycle starts over
All About Electric MotorsOperation of the Motor
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Images courtesy of Wikimedia Commonshttp://commons.wikimedia.org
+All About Electric MotorsAn Actual Toy Motor
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Brushes inside the motor
Transfer power from battery to commutator as the rotor shaft spins
All About Electric MotorsAn Actual Toy Motor
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The rotor shaft holds the armature and the commutator
The armature is a set of electromagnets, in this case three
The two ends of each wire (one wire for each pole) are soldered onto a terminal, and then each of the three terminals is wired to one plate of the commutator
All About Electric MotorsAn Actual Toy Motor
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Magnetic field provided by 2 curved permanent magnets
All About Electric MotorsAn Actual Toy Motor
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Images courtesy of HowStuffWorkshttp://howstuffworks.com
+All About Electric Motors
Build your own electric motor Wind the armature Wind the field coil Assemble the motor
Materials provided in kit
Assembly Instructions
What Are We Going To Do?
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+All About Electric Motors
Think about the classroom setting:What measure of performance could
you introduce to quantifythe success of themotor build?
As you work…
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+All About Electric Motors
Winding both the field coil and armature Use tape to hold pieces together as you wind
Cut the tubing to size after youwind the armature coil to ensureproper alignment
Keep the field coilwindings as flat aspossible to ensure thearmature can spin freely
A Few Helpful Tips
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+All About Electric Motors
You are a consultant tasked with adapting your proprietary electric motor to be used in a hair dryer.
What design modifications would you need to make?
What materials would you change?
What safety considerations would need to be addressed?
Design Discussion
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+All About Electric Motors
How would you quantify performance of the electric motor that students build?What properties would you measure?What additional materials would you
need?
What additional elements would you add to this activity?
Application Discussion
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Christopher LesterIEEE Educational Activities
Exercise 2:
Robotic Arm
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+Robot Arm
We will build a robot arm from simple materials
What will we do today?
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+Robot ArmWhy is this experiment useful to teachers and students?
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It teaches technological design
It requires mathematical calculations for design
It relates to the studies of motion and force
It requires communication through writing (design) and orally (explaining the design principles)
+Robot Arm
Geometry: Use visualization, spatial reasoning, and geometric modeling
to solve problems Analyze characteristics and properties of two- and three-
dimensional geometric shapes and develop mathematical arguments about geometric relationships
Problem Solving: Recognize and apply geometric ideas in areas outside of the
mathematics classroom Apply and adapt a variety of appropriate strategies
Communication: Communicate mathematical thinking coherently and clearly to
peers, teachers, and others
Principles & Standards for School Mathematics
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Canadarm 1, also known as Shuttle Remote Manipulator System
Used on the space shuttle to maneuver loads of up to 29 tons
Developed by SPAR Aerospace Ltd., out of Edmonton
Robot ArmThe Canadarm
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Canada’s primary contribution to the International Space Station
Mobile Servicing Station Space Station Remote
Manipulator Mobile Remote
Servicer Base System Special Purpose
Dexterous Manipulator
17 meters fully extended
Robot ArmThe Canadarm 2
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Dextre
+Robot Arm
We will build a robot arm from simple materials
The arm must pick up a plastic cup from a distance of 45cm Lift the cup to a height of at least 15cm Bring the cup back to rest and release it
Pick up cup upside down
Building the Canadarm 3
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+Robot ArmYou cannot get too close…
You cannot get any closer than 45cm to the cup at any time
CupStudent
Robot Arm
45cm
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+Robot ArmAvailable Materials
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+Robot Arm
Divide into teams of two (2)
Review the requirements
Discuss a solution and create a sketch of your design
Build a model of your design with given materials
Test your model
Outline and Procedures
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+Robot Arm
Discuss and agree upon a redesign If needed after testing, or to enhance the previous design
Rebuild your robot arm
Retest your model
Answer reflection questions as a team
Redesign after testing
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+Robot Arm
1. The arm must pick up a plastic cup from a distance of 45cm
Lift the cup to a height of at least 15cm
Bring the cup back to rest and release it
2. Lift and release the cup when it is upside down
Design requirements
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NEW DESIGN REQUIREMENT
Lift and release the cup when it is full with weight, or water bottle
Use materials on yourtable to fill cup(candy, pencils…)
Robot ArmUPDATE FROM SPACE AGENCY
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+Robot Arm
1. The arm must pick up a plastic cup from a distance of 45cm
Lift the cup to a height of at least 15cm
Bring the cup back to rest and release it
2. Lift and release the cup when it is upside down
3. Lift and release water bottle
Design requirements
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NEW DESIGN REQUIREMENT
Need a single device that can manipulate a cup as well as a pen.
Device can use twodifferent endmanipulators
Robot ArmUPDATE FROM SPACE AGENCY
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+Robot Arm
1. The arm must pick up a plastic cup from a distance of 45cm
Lift the cup to a height of at least 15cm
Bring the cup back to rest and release it
2. Lift and release the cup when it is upside down
3. Lift and release water bottle
4. Use the same design (possibly with a modified end manipulator) to lift a pen
Design requirements
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+Robot Arm
What was one thing you liked about your design? What is its main weakness?
What is one thing you would change about your design based on your experience
Are there algebraic and physical principles that can be applied to this activity?
How would you modify the instructions to create a better experience for the participants?
Reflection Questions
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