magnetic bearing preliminary design review team minimuffin lauren glogiewicz jacob beckner kevin...

Magnetic Bearing Preliminary Design

ReviewTeam 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 possibleo Fewer parts require maintenanceo 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

8-12 bits per magnet sent to

current control via FPGA I/O

Convert distance error to current

8x sensor distance in to FPGA

Software Functional Diagram

James

Design Constraints• Speed of Control

o Need a tight control loop between sensors & FPGAo Electromagnets need to be adjusted continuously

• Power

o Electromagnets are typically high powero 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 pinso 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 CostsItem 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: $1,600.76

Phil

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 Look into components with faster responseo Different sensing types: capacitive, magnetic field, etc.

• Time delay of current control

o Better components

Phil

Questions?