System and method for positioning a multi-pole magnetic structure

• US 8,779,879 B2
• Filed: 11/21/2013
• Issued: 07/15/2014
• Est. Priority Date: 04/04/2008
• Status: Expired due to Fees

• Current Assignee: Correlated Magnetics Research, LLC
• Original Assignee: Correlated Magnetics Research, LLC
• Inventors: Roberts, Mark D., Fullerton, Larry W., Richards, James Lee
• Primary Examiner(s): BARRERA, RAMON M
• Application Number:
  US14/086,924
• Publication Number:
  US 20140145809A1
• Time in Patent Office: 236 Days
• Field of Search: 335/285, 335/306
• US Class Current: 335/306
• CPC Class Codes: B42F 1/00 Sheets temporarily attached together without perforating; Means therefor
• CPC Class Codes: B42F 1/06 of flat cross-section , e.g. made of a piece of metal sheet
• CPC Class Codes: G09F 7/04 the elements being secured or adapted to be secured by magnetic means
• CPC Class Codes: H01F 7/02 Permanent magnets [PM]
• CPC Class Codes: H01F 7/021 Construction of PM H01F7/0278 takes precedence; PM compositions H01F1/032
• CPC Class Codes: H01F 7/0247 Orientating, locating, transporting arrangements
• CPC Class Codes: H01F 7/0252 PM holding devices H01F7/021, H01F7/0215, H01F7/0226 take precedence

Abstract

Systems and methods for arranging magnetic sources for producing field patterns having high gradients for precision positioning, position sensing, and pulse generation. Magnetic fields may be arranged in accordance with codes having a maximum positive cross correlation and a maximum negative cross correlation value in proximity in the correlation function, thereby producing a high gradient slope corresponding to a high gradient force or signal associated with the magnetic structure. Various codes for doublet, triplet, and quad peak patterns are disclosed. Applications include force and torque pattern generators. A variation including magnetic sensors is disclosed for precision position sensing. The forces or sensor outputs may have a precision zero crossing between two adjacent and opposite maximum correlation peaks.

Claims

1. A system for positioning a part comprising:

a first magnetic assembly comprising a plurality of magnetic field devices, said magnetic field devices arranged according to a first code, said first code derived from a source code by replacing each source code element by a product of the source code element and a first symbol, said first symbol having at least two elements, at least one element is nonzero;

said source code having an autocorrelation function with a single maximum magnitude and a maximum off maximum peak value less than half of the single maximum magnitude;

a second magnetic assembly comprising a second plurality of magnetic field devices, said magnetic field devices arranged according to a second code, said second code derived from said source code by replacing each source code element by a product of the source code element and a second symbol, said second symbol having at least two values, at least one value is nonzero;

wherein the first symbol and second symbol have the same length.

2. The system in accordance with claim 1, wherein the first symbol is 1, 0.

3. The system in accordance with claim 1, wherein the second symbol is 1, −

1.

4. The system in accordance with claim 1, wherein the first symbol is 1, 0, 0.

5. The system in accordance with claim 1, wherein the second symbol is 1, −

1, 1.

6. The system in accordance with claim 1, wherein the first symbol and second symbol are the same value.

7. The system in accordance with claim 1, wherein the source code is a Barker code, a PN code, or a Golomb ruler code.

8. The system in accordance with claim 1, wherein the second magnetic field device is a magnetic sensor.

9. The system in accordance with claim 8, further comprising a feedback mechanism configured to maintain a position based on said magnetic sensor.

10. The system in accordance with claim 1, wherein the second magnetic field device is a magnetic source.

11. The system in accordance with claim 10, wherein the magnetic source is a permanent magnet.

12. The system in accordance with claim 10, wherein the magnetic source comprises at least one electromagnet.

13. The system in accordance with claim 10, wherein the system comprises a stepping motor.

14. The system in accordance with claim 10, wherein the second magnetic field device comprises at least one inductor configured to produce an electrical pulse in response to a relative movement of said first magnetic assembly and said second magnetic assembly.

15. A method for generating a magnetic field force profile comprising:

providing a source code having source code elements;

generating a first code by replacing each source code element of said source code with a product of the source code element and a first symbol, said first symbol having at least two elements, at least one element is nonzero;

generating a second code by replacing each source code element of said source code with a product of the source code element and a second symbol, said second symbol having at least two elements, at least one element is nonzero;

said source code having an autocorrelation function with a single maximum magnitude and a maximum off maximum peak value less than half of the single maximum magnitude;

arranging a first magnetic assembly of magnetic elements in accordance with said first code;

arranging a second magnetic assembly of magnetic elements in accordance with said second code;

positioning said first magnetic assembly in proximity to said second magnetic assembly across an interface boundary; and

moving said first magnetic assembly relative to said second magnetic assembly in accordance with a path maintaining an alignment between said first magnetic assembly and said second magnetic assembly to produce a force function related to a cross correlation function of said first code and said second code.

16. The method in accordance with claim 15, wherein the first symbol is 1,0.

17. The method in accordance with claim 15, wherein the second symbol is 1, −

1.

18. The method in accordance with claim 15, wherein the first symbol is 1,0,0.

19. The method in accordance with claim 15, wherein the second symbol is 1, −

1, 1.

20. The method in accordance with claim 15, wherein the source code is a Barker code, a PN code, or a Golomb ruler code.

21. The method in accordance with claim 15, further including a step:

rotating said first code or said second code.

22. The method in accordance with claim 15, further including a step:

increasing or decreasing a length of the first code.

23. The method in accordance with claim 15, wherein the second symbol is a compound symbol generated by replacing elements of a third symbol in accordance with a product of the elements of the third symbol and a fourth symbol.