Magnetic position sensor system and method

Patent metadata

Field	Value
Publication number	US-12405322-B2
Application number	US-202318304570-A
Country	US
Kind code	B2
Filing date	Apr 21, 2023
Priority date	Dec 30, 2019
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

A position sensor system includes a magnetic source for generating a magnetic field, and a position sensor device movable relative to the magnetic source, or vice versa. The position sensor device comprises at least three magnetic sensor elements for measuring at least three magnetic field values of the magnetic field, and a processing circuit configured for determining at least two magnetic field gradients or magnetic field differences based on the at least three magnetic field values, and for deriving from the at least two magnetic field gradients or differences a first value indicative of a position of the position sensor device, and for deriving from the at least two magnetic field gradients or differences a second value indicative of integrity of the position sensor system.

First claim

The invention claimed is:

1. A position sensor device, comprising:
at least two magnetic sensors spaced apart in an X-direction, each of the at least two magnetic sensors configured to measure at least two orthogonal magnetic field components; and
a processing circuit configured for:
calculating two pairwise differences,
calculating and outputting a first signal indicative of a position of the device relative to a magnetic source, based on a ratio of said two pairwise differences,
calculating and outputting a second signal of a fault, the second signal based on a sum of squares of the two pairwise differences or a sum of absolute values of the two pairwise differences.

2. The position sensor device according to claim 1 , the position sensor device further comprising a substrate, wherein each of the at least two orthogonal magnetic field components are oriented parallel to the substrate.

3. The position sensor device according to claim 1 , the position sensor device further comprising a substrate, wherein a first of the at least two orthogonal magnetic field components is oriented parallel to the substrate and a second of the at least two orthogonal magnetic field components is oriented perpendicular to the substrate.

4. The position sensor device according to claim 1 , wherein the second signal is based on a comparison of the sum of squares or the sum of absolute values with one or more threshold values.

5. The position sensor device according to claim 1 , wherein the position comprises an angular position.

6. The position sensor device according to claim 1 , wherein the position comprises a linear position.

7. The position sensor device according to claim 1 ,
wherein each of the at least two magnetic sensors comprises a horizontal hall element and a vertical hall element; or
wherein each of the at least two magnetic sensors comprises two vertical Hall elements with their axes of maximum sensitivity oriented perpendicular to each other.

8. The position sensor device according to claim 1 , wherein each of the at least two magnetic sensors comprises an integrated magnetic concentrator IMC and two horizontal hall elements arranged near a periphery of the integrated magnetic concentrator.

9. A position sensor system, comprising:
the position sensor device according to claim 1 ; and
the magnetic source;
wherein the magnetic source comprises a magnet having only two poles or having at least two poles.

10. A position sensor device, comprising: three magnetic sensors located on a virtual circle and spaced apart by multiples of 120°, each of the three magnetic sensors configured to measure a magnetic field component oriented perpendicular to a substrate of the device; and
a processing circuit configured for:
calculating an average of the measured magnetic field components,
calculating three difference signals, each difference signal comprising a difference between one of the measured magnetic field components and the average,
calculating a first signal of an angular position of the device relative to a magnetic source based on the difference signals,
calculating and outputting a second signal of an integrity signal, a fault signal, or a magnet signal of a presence or absence of a magnet, and
wherein the second signal is based on a sum of squares of the difference signals or a sum of absolute values of the difference signals.

11. The position sensor device according to claim 10 , wherein each of the three magnetic sensors comprises a horizontal hall element.

12. The position sensor device according to claim 10 , wherein the second signal is based on a comparison of the sum of squares of the difference signals or the sum of absolute values of the difference signals with one or more threshold values.

13. The position sensor device according to claim 10 , wherein the substrate comprises a semiconductor substrate.

14. A position sensor system, comprising:
the position sensor device according to claim 10 ; and
the magnetic source;
wherein the magnetic source comprises a magnet having only two poles or having at least two poles.

15. A position sensor device, comprising:
a substrate comprising at least four pairs of sensor elements located on a virtual circle, each pair configured for measuring magnetic field components oriented in different directions parallel to the substrate; and
a processing circuit configured for:
determining at least four magnetic field gradients along at least four different directions parallel to the substrate and angularly spaced by 45°, based on said measured magnetic field components,
calculating a first signal of a position of the position sensor device relative to a magnetic source,
calculating and outputting a second signal of an integrity signal, a fault signal, or a magnet signal of a presence or absence of a magnet, the second signal based on the following formula:
signal 2=( dBx/dx−dBy/dy ) 2 +( dBu/du−dBv/dv ) 2

or a value derived therefrom,
wherein Bx is a magnetic field component oriented in a first direction X parallel to the substrate, By is a magnetic field component oriented in a second direction Y parallel to the substrate and perpendicular to the first direction X, Bu is a magnetic field component oriented in a third direction U parallel to the substrate and forming an angle of 45° with the first direction X, and Bv is a magnetic field component oriented in a fourth direction V parallel to the substrate and perpendicular to the third direction U.

16. The position sensor device according to claim 15 , wherein the sensor elements are provided in a single chip.

17. The position sensor device according to claim 15 ,
wherein the position sensor device comprises at least one integrated magnetic concentrator; and
wherein each of the sensor elements comprises a horizontal hall element arranged near a periphery of said at least one integrated magnetic concentrator.

18. A position sensor system, comprising:
the position sensor device according to claim 15 ; and
the magnetic source;
wherein the magnetic source comprises a magnet having only four poles or having at least four poles.

19. The position sensor system according to claim 18 , wherein the magnet is rotatable about a rotation axis and the position sensor device is located on said rotation axis.

20. The position sensor system according to claim 19 , wherein the substrate comprises a semiconductor substrate oriented orthogonal to the rotation axis.

Assignees

• Melexis Tech Sa

Inventors

• Close Gael
• Huber Lindenberger Samuel

Classifications

• G01R33/07

  Hall effect devices · CPC title

• G01D5/145 Primary

  influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06) · CPC title

• G01D5/24457

  Failure detection · CPC title

• G01D3/036

  on measuring arrangements themselves · CPC title

• G01D3/08

  with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown · CPC title