DESIGN OF MAGNETIC LEVITATION DEMONSTRATION APPARTUS

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1 TEAM 11 WINTER TERM PRESENTATION DESIGN OF MAGNETIC LEVITATION DEMONSTRATION APPARTUS Fuyuan Lin, Marlon McCombie, Ajay Puppala Xiaodong Wang Supervisor: Dr. Robert Bauer Dept. of Mechanical Engineering, Dalhousie University April 4,

2 2 Presentation Overview 1. Project Description 2. Design Requirements 3. Product Architecture 4. Component Selection 5. Conceptual Design i. Design Alternatives ii. Chassis Design 6. Control System i. Plant Subsystem ii. Circuit Design: Amplifier & Driver iii. Controller 7. System Implementation 8. GUI 9. Budget 10. Assessing Requirements 11. Future Considerations

Demonstrate different control theories taught in MECH 4900

3 1. Project Description 3 Design and build a magnetic levitating device To levitate an object magnetically Demonstrate different control theories taught in MECH 4900 Systems II course Arduino (MCU) & Circuitry for Levitation Object Levitating

4 4 2. Design Requirements Demonstrative Requirements Levitate object magnetically Compare simulated and experimental position of the object being levitated Lag, lead, lag-lead P, PI, and PID control User Requirements Graphical User Interface (GUI) to interact with device Plug n Play Safe and Ergonomic

5 5 2. Design Requirements Visual Requirements Viewable from ft. (back of the classroom) Levitate the object at least 2-4 cm away from the coil Power Requirements Conventional 120 VAC input No potential electrical risk to the user Operating Budget $1,500

6 3. Product Architecture 6 General Schematic of demonstration device

7 4. Component Selection 7 Levitation Technique Permanent Magnets Electromagnets Electrodynamics Superconductors Object Material Shape Motion MCU Sensor Chrome Steel Rectangular Horizontal prism Arduino Hall Effect Regular Steel LEGO Circular Vertical Mindstorm disk NXT 2.0 Reflective Neodymium Solid sphere Composite Hollow sphere BeagleBoard Table shows selected components of the subsystem Optical Proximity Altera DE2 Photoelectric

8 Electromagnetic Levitation 8 Strength of magnetic field generated by the coil depends on the current supplied Control challenge: F Electromagnet current2 distance 2 Electromagnetic Levitation

9 5.1. Design Alternatives 9 1.Single Electromagnet with Hall Effect Sensor 2. Double Electromagnet Design 3. Multiple Coil Parallel Arrangement

10 5.2. Chassis Design 10 Design evolution of the chassis Material Mass (kg) Cost Aluminum $235 ABS Plastic 1.50 $675 Wood (Birch Ply) 1.20 $126 Material options for the chassis

11 6. Control System 11 Input Desired Position + _ Error Current Controller Actual Plant Position Unity Feedback System

12 6.1. Plant Subsystem 12 Current Levitation Position Change Sensor Voltage Output Breakdown of the Plant System

Electromagnet Design Requirements 13 Air Gap, X = 20 mm, Object Mass = 20 g, F object = 0.

13 Electromagnet Design Requirements 13 Air Gap, X = 20 mm, Object Mass = 20 g, F object = N Coil Turnings, N = 1000 For pole D = 3 cm, A= πd2 = m2 4 Permeability of free space, μ o = 4π 10 7 V s A m

Electromagnet Selection 14 Height of the electromagnet Design Criteria 12 VDC Pneumatic Solenoid < 7 cm 3.65 cm Core Diameter 3 cm 2 cm Cu wire gage Max. 22 (Dia. 0.

14 Electromagnet Selection 14 Height of the electromagnet Design Criteria 12 VDC Pneumatic Solenoid < 7 cm 3.65 cm Core Diameter 3 cm 2 cm Cu wire gage Max. 22 (Dia ) Dia Coil Turnings 1000 ~2000 Field Strength wb/m 2 -Satisfactory Test Results -No heat issues Assessment of 12 VDC Pneumatic Solenoid based on design requirements

15 6.1. Plant Subsystem 15 Current Levitation Position Change Sensor Voltage Output Breakdown of the Plant System Hall Effect Sensor

16 16 Sensor Component Hall Effect Sensor Analog position sensor (Solid State Type SS49 Series) Size: 30 x 4 x 2 mm Range of Detection: up to 4 cm Unit Cost: $2.50 Picture Courtesy of Honeywell.

17 Design Refinement 17 Initial Design Final Design Addition of new Hall Effect Sensor to differentiate Electromagnet signal

18 18 Sensor Testing

19 Sensor Circuit Design 19 Circuit for Differential Amplification of Sensor Ouput

20 6.1. Plant Subsystem 20 Current Levitation Position Change Sensor Measurement Voltage Output Sensor Calibration Actual Position 2 Hall Effect Sensors

21 Sensor Voltage (V) 21 Position Sensor Calibration 3.50 Hall Effect Sensor Calibration Actual Distance (mm)

22 6.3. Control System 22 Input Desired Position + _ Error Current Controller Actual Plant Position Unity Feedback System

23 6.3. Controller Component Microcontroller - Arduino Mega 2560 4 Hardware serial ports

23 Controller Component Microcontroller - Arduino Mega Hardware serial ports for communication with MATLAB Runs control algorithms Cost: $55 Picture Courtesy of Arduino

7. System Implementation 24 Receive Data

24 7. System Implementation 24 Receive Data Levitation Control Serial Communication Arduino & Real Time Arduino uses feedback data from sensors to manipulate position MATLAB & Arduino Manipulation of control parameters Retrieval of feedback data

25 25 8. PID Controller

26 26 8. Budget ELECTRONICS CHASSIS Materials Unit Cost Amount Cost Arduino $ $ Hall Effect Sensor $ $42.78 Potentiometer $ $54.80 Operation Amplifier $ $3.20 Power Supply Unit $ $77.42 Neodymium Magnet $ $4.99 USB Cable $ $12.00 Electromagnet $ $38.97 Other Parts - - $55.51 Wood (61 x 121 x 2.5 cm ) $ $18.45 Acrylic glass $ $27.98 Aluminum sheet $ $15.93 Other Parts - - $22.38 Sub Total $ Summary of Materials Cost

27 8. Budget 27 Sub Total $ Total Shipping $85.11 Total Taxes $65.14 Contributions -$ Total $ Summary of Budget

28 28 9. Assessing Requirements Demonstrative Requirements Levitate object magnetically ~ Compare desired and measured controller variables Lag, lead, lag-lead compensation techniques P, PI, and PID control User Requirements Graphical User Interface (GUI) to interact with device Plug n Play Safe and Ergonomic

29 9. Assessing Requirements 29 Visual Requirements Viewable from ft. back of the classroom Levitate the object at least 2-4 cm away from the coil Power Requirements Conventional 120 VAC input No potential electrical risk to the user Operating Budget $1,500

30 10. Future Considerations 30 Build more powerful electromagnet or add an extra electromagnet to repel the levitated object Might increase the range of levitation. Implementation of lag, lead, and lag-lead compensator. Use different microcontroller capable of serial or other form of communication without effecting the frequency of the feedback signal. Use different interface instead of MATLAB for example LabView

31 Acknowledgements 31 Dr. Y.J. Pan Mechanical Dept. Professor Dr. Timothy Little Electrical Dept. Professor Al-Mokhtar O. Mohamed Post-Doctoral Position Mech. Dept. Jonathan MacDonald Electrical Technician Angus MacPherson Mechanical Technician Reg Peters Wood Workshop Technician

32 32 Thank You & Questions?

40 References 40 Arduino UNO webpage. Retrieved Mar. 30, 2014 ATmega238 datasheet. Retrieved Mar. 30, 2014 Honeywell SS49 datasheet. Retrieved Mar. 30, 2014 "RobotShop : The World's Leading Robot Store." RobotShop. N.p., n.d. Sun. Mar. 30, 2014 MathWorks MATLAB/Simulink website. Retrieved Mar. 30, 2014 Mikonikuv Blog, Arduino Magnet Levitation detailed description. Retrieved Nov. 20, 2013 Williams, Lance. "Electromagnetic Levitation Thesis." N.p., Web. 28 Oct

41 Control System Question

System Model Ball Model: Static equilibrium: mg = C i o 2 x o 2 Inverse Square Law! Magnetic Plant Constant: C = mgx o 2 2 = 1.

42 System Model Ball Model: Static equilibrium: mg = C i o 2 x o 2 Inverse Square Law! Magnetic Plant Constant: C = mgx o 2 2 = Nm2 i o A 2 Linearization of electromagnetic force using Taylor series approximation: C i2 =C i o C 2i o x 2 x 2 o x 3 x x o + C o C i2 2 2 =C i o C 2i o x 2 x 2 o 2 2 x o 3 x C 2i o x o 2 i 2i o x o 2 (i i o) Force Balance F net = ma, mx = mg F Electromagnetic Force F(i, x) = C i2 x 2 For change in position, x = x x o mx C mx = mg C i2 2i o 2 x o 3 x 2 x = C 2i o x o 2 Thus, the differential equation: x 3695 x = 63 i s 2 X s 26.59X s = I s X s I s = s m o = 0.02 kg, x o = 0.02 m, i o = A i

43 System Model Electromagnet Model Electromagnetic coil driving circuit

44 System Model Simplified Circuit Electromagnet Model V in L di V in L d dt Laplace transform: V in (s) Rearranging the equation V out = V in dt V out = 0 V out R V out = 0 Ls R + 1 V out(s) = 0 1 L R s + 1 Finally, V out = I R : L = 87 mh, R = 17.5 Ω I V in = 1 R = L R s s + 1

45 Control Systems Electromagnet Voltage Input Plant (Levitation) Position Change Ball Combination of Electromagnet & Ball Model I s X s I s V s Thus, the uncompensated system OLTF = X s = V s X s V s = s s Note: Negative controller gain is required

MAGNETIC LEVITATION DEMONSTRATION APPARATUS

MAGNETIC LEVITATION DEMONSTRATION APPARATUS TEAM 11 FALL TERM PRESENTATION Fuyuan Lin, Marlon McCombie, Ajay Puppala, Xiaodong Wang Project Supervisor : Dr. Robert Bauer Project Coordinator : Dr. Clifton