Control of Halbach Array Magnetic Levitation System Height

By: Dirk DeDecker Jesse VanIseghem Advised by: Dr. Winfred Anakwa Mr. Steven Gutschlag

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Outline

• Introduction Project Summary Block Diagram Functional Requirements Changes to Original Proposal Work Completed Schedule of Tasks Patents References

Introduction

• • Maglev suspension technology can be used in high speed train applications Maglev suspension allows trains to accelerate to over 300 mph and reduces maintenance by almost eliminating moving parts

Previous Work

• Dr. Sam Gurol and Dr. Post have worked on “The General Atomics Low Speed Urban Maglev Technology Development Program” utilizing the rotary track method

Previous Work Cont.

• • Work by Paul Friend in 2004 – Levitation Equations – Matlab GUI Work by Glenn Zomchek in 2007 – Design of system using Inductrack method – Successful levitation to .45 mm.

Project Summary

• The goals of our project are: – Improve upon system used in previous years – Demonstrate successful levitation

Original System Block Diagram

Functional Requirements

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Halbach Array Requirements:

– 6 mm cube magnets shall be used to create the Halbach arrays.

– Each magnet shall have peak strength of 1.21 Tesla.

– A Halbach array of 5 by 25 magnets shall be constructed.

• Wavelength of 28 mm • Total length, with glue, of approximately 175mm • Total width, with glue, of approximately 30 mm

Functional Requirements Cont.

• • A new wheel shall be fabricated with a radius of 9 inches A new aluminum Inductrack shall be fabricated with 4 mm conducting strips with 1 mm spacing between the strips

Changes to Original Proposal

• • We will focusing on the levitation of our magnet device We will not be setting up closed loop control of our system – Not enough time this year to order new controller and model the controller and engine – Working through equations and getting parts manufactured has taken longer than expected

Work Completed

• • Ran Matlab GUI and worked equations to decide final parameters Parts ordered and arrived: – Copper sheet for track – Magnets – Block of LDPE for wheel – Balsa wood for train

Work Completed Cont.

• Designed and cut balsa wood device to house magnets Magnets will go here

Work Completed Cont.

• • • Magnet device shall be array of 5 by 25 magnets Makes our arc length approximately 8”, with an angle of 25 degrees to either side – cos(25) = .9063

– Arc length s = 9*0.436 = 3.93

This arc length keeps 90% of the force in the vertical direction

Work Completed Cont.

Fv = Fi*cos( Θ) Fi Θ Force Diagram

Work Completed Cont.

• • Drawings of track and wheel produced in ProE and AutoCad These drawings were sent off to machining companies to get estimates

Work Completed Cont.

• Decided to switch from aluminum track to copper – Lower resistivity of copper(Cu = 1.68x10

-8 Ω*m, Al = 2.82x10

-8 to decrease, thus increasing the Lift/Drag ratio Ω*m) causes resistance • • • • R = PcRc/(Nt*c*Ns) , where Rc is the resistivity Lift/Drag – 2*π*v/λ*(L/R) Aluminum Lift/Drag ratio = 0.102

Copper Lift/Drag ratio = 0.171

– Allows for levitation at lower speeds

Work Competed Cont.

• Copper Sheet: – To maximize lift, a large amount of inductance and low resistance is desired – L = μ 0 w/(2kd c ) , where d c is the center to center spacing of conducting strips and w is the track width – Narrow, wide slits are desired to increase L

Work Completed Cont.

• LDPE Wheel: • Used low density in order to help decrease mass of wheel

Work Completed Cont.

• • Called machining companies to get estimates on machining of wheel and track – Decided on Tri-City Machining. After we drop them off, parts will be machined in approximately one week Weekly updates added to webpage

Schedule of Tasks

• • • • • Get parts machined at machine shop Glue magnets into balsa wood Design safety measures for system Put together wheel, track, motor, and magnet array device Test system for levitation

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Applicable Patents

• Richard F. Post Magnetic Levitation System for Moving Objects U.S. Patent 5,722,326 March 3, 1998 Coffey; Howard T.

Propulsion and stabilization for magnetically levitated vehicles U.S. Patent 5,222,436 June 29, 2003 Richard F. Post Inductrack Magnet Configuration U.S. Patent 6,633,217 B2 October 14, 2003 Richard F. Post Inductrack Configuration U.S. Patent 629,503 B2 October 7, 2003 Richard F. Post Laminated Track Design for Inductrack Maglev System U.S. Patent Pending US 2003/0112105 A1 June 19, 2003 • • Coffey; Howard T.

Magnetic Levitation configuration incorporating levitation, guidance and linear synchronous motor U.S. Patent 5,253,592 October 19, 1993 Levi;Enrico; Zabar;Zivan Air cored, linear induction motor for magnetically levitated systems U.S. Patent 5,270,593 November 10, 1992 • Lamb; Karl J. ; Merrill; Toby ; Gossage; Scott D. ; Sparks; Michael T. ;Barrett; Michael S.

U.S. Patent 6,510,799 January 28, 2003

Works Consulted

• Glenn Zomchek. Senior Project. “Redesign of a Rotary Inductrack for Magnetic Levitation Train Demonstration.” Final Report, 2007.

• • • Paul Friend. Senior Project. Magnetic Levitation Technology 1. Final Report, 2004.

Gurol, Sam. E-mail (Private Conversation) Post, Richard F., Ryutov, Dmitri D., “The Inductrack Approach to Magnetic Levitation,” Lawrence Livermore National Laboratory.

• Post, Richard F., Ryutov, Dmitri D., “The Inductrack: A Simpler Approach to Magnetic Levitaiton,” Lawrence Livermore National Laboratory.

• Post, Richard F., Sam Gurol, and Bob Baldi. "The General Atomics Low Speed Urban Maglev Technology Development Program." Lawrence Livermore National Laboratory and General Atomics.