Control of Halbach Array Magnetic Levitation System Height

Control of Halbach Array Magnetic Levitation System Height By: Dirk De. Decker Jesse Van. Iseghem Advised by: Dr. Winfred Anakwa Mr. Steven Gutschlag

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 • 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 175 mm • 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 Pro. E and Auto. Cad • 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. 68 x 10 -8 Ω*m, Al = 2. 82 x 10 -8 Ω*m) causes resistance to decrease, thus increasing the Lift/Drag ratio • R = Pc. Rc/(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/(2 kdc) , where dc 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

Applicable Patents • Richard F. Post Magnetic Levitation System for Moving Objects U. S. Patent 5, 722, 326 March 3, 1998 • Richard F. Post Inductrack Magnet Configuration U. S. Patent 6, 633, 217 B 2 October 14, 2003 • Richard F. Post Inductrack Configuration U. S. Patent 629, 503 B 2 October 7, 2003 • Richard F. Post Laminated Track Design for Inductrack Maglev System U. S. Patent Pending US 2003/0112105 A 1 June 19, 2003 • Coffey; Howard T. Propulsion and stabilization for magnetically levitated vehicles U. S. Patent 5, 222, 436 June 29, 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.