All about Electric Motors Building a Robot Arm

1. TISP: Montreal15 – 16 May 2009 All about Electric MotorsBuilding a Robot Arm Christopher Lester Yvonne Pelham Douglas Gorham Kapil Dandekar

2. Exercise 1: ElectricMotors Christopher LesterIEEE Educational Activities

3. 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

4. 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

5. 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

6. 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! • Computers • Cooling fans • Furnaces • Boilers • Air conditioners • Automobiles • Washer/Dryer • Elevators • Refrigerator • CD Player • Printer • Fax Machine • Power Tools • Cell Phone Vibrate Mode

7. All About Electric Motors Parts of the Electric Motor 6 Main Parts 3 1 4 6 2 5

8. All About Electric Motors Operation of the Motor • 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

9. All About Electric Motors Operation of the Motor • Motor shaft rotates clockwise • Torque continues to be generated in the clockwise direction

10. All About Electric Motors Operation of the Motor • 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

11. All About Electric Motors Operation of the Motor • 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 Images courtesy of Wikimedia Commonshttp://commons.wikimedia.org

12. All About Electric Motors An Actual Toy Motor

13. All About Electric Motors An Actual Toy Motor • Brushes inside the motor • Transfer power from battery to commutator as the rotor shaft spins

14. All About Electric Motors An Actual Toy Motor • 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

15. All About Electric Motors An Actual Toy Motor • Magnetic field provided by 2 curved permanent magnets Images courtesy of HowStuffWorkshttp://howstuffworks.com

16. 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?

17. All About Electric Motors Think about the classroom setting: What measure of performance couldyou introduce to quantifythe success of themotor build? As you work…

18. 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

19. 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

20. 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

21. Exercise 2: Robotic Arm Christopher LesterIEEE Educational Activities

22. Robot Arm We will build a robot arm from simple materials What will we do today?

23. Robot Arm Why is this experiment useful to teachers and students? 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)

24. 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

25. Robot Arm The Canadarm • 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

26. Robot Arm The Canadarm 2 • 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 Dextre

27. 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

28. Robot Arm You cannot get too close… Robot Arm Student Cup 45cm You cannot get any closer than 45cm to the cup at any time

29. Robot Arm Hanger Cardboard Clothespins Popsicles sticks Rubber bands Binder clips Paper clips Golf pencils Tape Paper fasteners Plastic bag Available Materials

30. 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

31. 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

32. Robot Arm 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 Lift and release the cup when it is upside down Design requirements

33. Robot Arm 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…) UPDATE FROM SPACE AGENCY

34. Robot Arm 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 Lift and release the cup when it is upside down Lift and release water bottle Design requirements

35. Robot Arm NEW DESIGN REQUIREMENT Need a single device that can manipulate a cup as well as a pen. Device can use twodifferent endmanipulators UPDATE FROM SPACE AGENCY

36. Robot Arm 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 Lift and release the cup when it is upside down Lift and release water bottle Use the same design (possibly with a modified end manipulator) to lift a pen Design requirements

37. 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