High performance magnetic angle sensor

Patent metadata

Field	Value
Publication number	US-11280637-B2
Application number	US-201916683803-A
Country	US
Kind code	B2
Filing date	Nov 14, 2019
Priority date	Nov 14, 2019
Publication date	Mar 22, 2022
Grant date	Mar 22, 2022

Abstract

A sensor is disclosed for detecting an orientation of a magnet, the sensor comprising: a first sensor array including a first plurality of sensor elements that are arranged along a first line; a second sensor array including a second plurality of sensor elements that are arranged along a second line; and a processing circuitry configured to: detect a magnetic field produced by the magnet by using the first sensor array, and identify a first point on the first line where at least one component of the magnetic field has a predetermined value; detect the magnetic field by using the second sensor array, and identify a second point on the second line where at least one component of the magnetic field has the predetermined value; detect an orientation of the magnet relative to the sensor based on the first point and the second point; and output an indication of the orientation of the magnet based on the first point and the second point.

First claim

The invention claimed is:

1. A sensor for detecting an orientation of a magnet, the sensor comprising:
a first sensor array including a first plurality of sensor elements that are arranged along a first line, the first sensor array including at least three sensor elements;
a second sensor array including a second plurality of sensor elements that are arranged along a second line, the second sensor array including at least three sensor elements; and
a processing circuitry configured to:
identify a first pair of sensor elements in the first sensor array, the first pair including a sensor element at which a component of a magnetic field is positive and a sensor element at which the component of the magnetic field is negative;
identify a first point on the first line where the component of the magnetic field has a predetermined value based on respective readings that are taken using the sensor elements in the first pair;
identify a second pair of sensor elements in the second sensor array, the second pair including a sensor element at which the component of the magnetic field is positive and a sensor element at which the component of the magnetic field is negative;
identify a second point on the second line where the component of the magnetic field has the predetermined value based on respective readings that are taken using the sensor elements in the second pair;
detect the orientation of the magnet relative to the sensor based on the first point and the second point; and
output an indication of the orientation of the magnet based on the first point and the second point.

2. The sensor of claim 1 , wherein the orientation of the magnet is detected further based on a distance between the first sensor array and the second sensor array.

3. The sensor of claim 1 , wherein:
the component of the magnetic field includes a z-axis component of the magnetic field;
the first point includes a location on the first line where the z-axis component of the magnetic field is estimated to be equal to zero, and
the second point includes a location on the second line where the z-axis component of the magnetic field is estimated to be equal to zero.

4. The sensor of claim 1 , wherein:
detecting the orientation of the magnet includes detecting an angle between a zero-crossing line and one of the first line and the second line, and
the zero-crossing line extends between the first point and the second point.

5. The sensor of claim 1 , wherein either the first plurality of sensor elements or the second plurality of sensor elements comprises a Hall effect element.

6. The sensor of claim 1 , wherein the component of the magnetic field includes a z-axis component of the magnetic field.

7. The sensor of claim 1 , wherein the first sensor array has a non-uniform pitch, and the second sensor array has a non-uniform pitch.

8. The sensor of claim 1 , wherein the sensors in the first pair are adjacent to one another, and the sensors in the second pair are adjacent to one another.

9. A sensor for detecting an orientation of a magnet, the sensor comprising:
a first sensor array including a first plurality of sensor elements that are arranged along a first line;
a second sensor array including a second plurality of sensor elements that are arranged along a second line;
a third sensor array including a third plurality of sensor elements that are arranged along a third line, the third line being transverse to the first line and the second line; and
a fourth sensor array including a fourth plurality of sensor elements that are arranged along a fourth line, the fourth line being transverse to the first line and the second line,
a processing circuitry configured to: detect the orientation of the magnet by using the first sensor array, the second sensor array, the third sensor array and the fourth sensor array; and output an indication of the orientation of the magnet.

10. A sensor for detecting an orientation of a magnet, the sensor comprising:
a first sensor array including a first plurality of sensor elements that are arranged along a first line, the first plurality of sensor elements including at least three sensor elements;
a second sensor array including a second plurality of sensor elements that are arranged along a second line, the second plurality of sensor elements including at least three sensor elements; and
a processing circuitry configured to:
identify a first pair of sensor elements in the first sensor array where a magnetic field produced by the magnet changes sign;
identify a first point on the first line where at least one component of the magnetic field has a predetermined value, the first point being identified based on respective readings that are taken using the sensor elements in the first pair;
identify a second pair of sensor elements in the second sensor array where the magnetic field produced by the sensor changes sign;
identify a second point on the second line where the at least one component of the magnetic field has a predetermined value, the second point being identified based on respective readings that are taken using the sensor elements in the second pair;
detect the orientation of the magnet relative to the sensor based on the first point, the second point, and a distance between the first sensor array and the second sensor array; and
output an indication of the orientation of the magnet.

11. The sensor of claim 10 , wherein detecting the magnetic field with the first sensor array includes detecting only a z-axis component of the magnetic field and detecting the magnetic field with the second sensor array includes detecting only the z-axis component of the magnetic field, the z-axis component of the magnetic field being transverse to a plane of the magnet.

12. The sensor of claim 10 , wherein the sensor elements in the first pair are adjacent to one another, and the sensor elements in the second pair are adjacent to one another.

13. The sensor of claim 10 , wherein the first line is a straight line, and the second line is a straight line.

14. The sensor of claim 10 , wherein either the first plurality of sensor elements or the second plurality of sensor elements includes a Hall effect element.

15. A method for detecting an orientation of a magnet relative to a sensor, the sensor including a first sensor array having at least three sensor elements that are arranged along a first line and a second sensor array having at least three sensor elements that are arranged along a second line, the method comprising:
identifying a first pair of sensor elements in the first sensor array where a magnetic field produced by the magnet changes sign;
identifying a first point on the first line where at least one component of the magnetic field has a predetermined value based on respective readings that are taken using the sensor elements in the first pair;
identifying a second pair of sensor elements in the second sensor array where the magnetic field produced by the magnet changes sign;
identifying a second point on the second line where the at least one component of the magnetic field has the predetermined value based on respective readings that are taken using the sensor elements in the second pair;
detecting the orientation of the magnet relative to the sensor based on the first point and the second point; and
outputting an indication of the orientation of the magnet based on the first point and the second point.

16. The method of claim 15 , wherein:
the first point includes a location on the first line where a z-axis component of the magnetic field is estimated to be equal to z

Assignees

• Allegro Microsystems Llc

Inventors

• Diaconu Aurelian
• David Paul A

Classifications

• G01D5/145 Primary

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