Magnetic Bearing
Preliminary Design
Review
Team miniMuffin
Lauren Glogiewicz
Jacob Beckner
Kevin Bodkin
James Holley
Philip Terry
Project Description
• Different bearing design using magnetic fields
• Electromagnets will levitate an axle
• Optical sensors monitor position of axle
• FPGA interprets data to control electromagnets
• System less prone to mechanical restraints
Lauren
Why Magnetic Bearings?
• Eliminates friction present in mechanical bearings
o Higher speed of rotation possible
o Fewer parts require maintenance
o Not as susceptible to heat
VS
Lauren
Project Objectives
Lauren
Concept: 8-Magnet Bearing
Lauren
First Objective:
1D Proof of Concept Design
Lauren
Final Objective: Magnetic
Ring Bearing with Axial Bearing
James
Final Objective: Magnetic
Ring Bearing with Axial Bearing
James
Hardware Functional Diagram
James
Software Functional Diagram
8x sensor distance in to FPGA
Convert distance error to current
8-12 bits per magnet sent to
current control via FPGA I/O
James
Design Constraints
• Speed of Control
o
o
Need a tight control loop between sensors & FPGA
Electromagnets need to be adjusted continuously
• Power
o
o
Electromagnets are typically high power
Bearings only useful if energy efficient
• Budget
o
Certain components could be expensive
James
Major Components
• Optical Sensors
• FPGA: Hardware & Software Interface
• Current Control
• Electromagnets
• Power Supply
Jake
Sensing Devices
• Optical sensors will track axle position
• Sensors will be paired with electromagnets
• Vital to the positioning feedback loop
Jake
Altera Flex 6000 FPGA
• 199 I/O pins
o 8 magnet
control with 12-bit
accuracy
• Re-programmable with
Altera software
• 100 MHz maximum
clock frequency
Jake
Electromagnets
• Found source of low-cost, high-power magnets
• Currently testing two models:
o
1" Magnet: 3 V, 5.5 W, 25 lb holding force
o
2" magnet: 6 V, 7 W, 105 lb holding force
Kevin
Current Control
• Will receive information from the FPGA
• Information fed to D/A converter to amplifier
• Amplifier will feed into BJT-based current source
• Will change the strength of the electromagnets
• Current limited based on the magnet used
Kevin
Power Supply
• Need the following:
o 15 V for OpAmps
o 6 V +/- mV for magnets
o 3.3 V for integrated circuits
• Initial work using power supplies & 12 V batteries
• Final design should use wall power
Kevin
Prediction of Material Costs
Item
Part No.
Cost
Quantity
Total Cost
FPGA
Altera FLEX 6000
$43
2
$86.00
Electromagnets
EM 200
$41.61
15
$624.15
Optical Sensors
Sharp GP2Y0D805Z0F
$3.70
15
$55.50
BJT
TRANS NPN 10VCEO 5A
$0.38
25
$9.50
Op Amps
$1.00
25
$25.00
Capacitors
$0.60
100
$60.00
Resistors
$0.60
100
$60.00
High Power Diodes
$1.71
15
$25.65
Wire
Wire T Lead Plastic 22AG
$18.00
5
$90.00
Nuts, Bolts, Screws
Aluminum (25 pack)
$9.58
3
$28.74
Aluminum
6ft x 1/4" x 2"
$30.22
1
$30.22
Machining
$200.00
1
$200.00
PCB
$60
3
$180.00
Shipping and Handling
$10.00
6
$60.00
Posters/Presentation
$70
$70
Total:
Phil
$1,600.76
Sources of Funding
• UROP
• Boettcher Scholar Educational Enrichment Grant
• Engineering Excellence Fund Mini Grant
Phil
Division of Labor
• For preliminary steps, we will divide as follows:
o
Jake: Interfacing/ programming FPGA
o
James: Electromagnets and supporting electronics
o
Kevin: Power electronics
o
Lauren: Mechanical design
o
Phil: Sensors and documentation
Phil
Timeline
Phil
Risks and Contingency Plan
• Mechanical Problems
o
Some parts manufactured by other people
• Time delay of sensors
o
o
Look into components with faster response
Different sensing types: capacitive, magnetic field, etc.
• Time delay of current control
o
Better components
Phil
Questions?