Device and method for determining an orientation of a magnet, and a joystick

Patent metadata

Field	Value
Publication number	US-11921173-B2
Application number	US-202217838684-A
Country	US
Kind code	B2
Filing date	Jun 13, 2022
Priority date	Jun 18, 2021
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

Abstract

A method of determining an orientation α,β of a magnet which is pivotable about a reference position having a predefined position relative to a semiconductor substrate, comprising: a) determining at least two of the following magnetic field gradients: i) a first magnetic field gradient dBx/dx; ii) a second magnetic field gradient dBy/dy; iii) a third magnetic field gradient dBz/dx; iv) a fourth magnetic field gradient dBz/dy; b) determining a first angle α based on at least one of the magnetic field gradients; c) determining a second angle β based on at least one of the magnetic field gradients. A sensor device is configured for performing this method. A sensor system includes such sensor device and a magnet, optionally connected to a joystick.

First claim

The invention claimed is:

1. A sensor device for determining a first and a second angle indicative of an orientation of a magnet having an axis, the sensor device comprising:
a semiconductor substrate comprising a plurality of magnetic sensors configured for determining at least iii) and iv) of the following:
i) a first magnetic field gradient of a first magnetic field component oriented in a first direction parallel to the semiconductor substrate along said first direction; and
ii) a second magnetic field gradient of a second magnetic field component oriented in a second direction parallel to the semiconductor substrate and perpendicular to the first direction, along said second direction; and
iii) a third magnetic field gradient of a third magnetic field component oriented in a third direction perpendicular to the first direction along said first direction; and
iv) a fourth magnetic field gradient of the third magnetic field component oriented in a fourth direction perpendicular to the second direction along said second direction;

a processing circuit configured for:
determining said first angle based on at least the third magnetic field gradient; and
determining said second angle based on at least the fourth magnetic field gradient.

2. The sensor device according to claim 1 , wherein the plurality of magnetic sensors comprises a first sensor, a second sensor, a third sensor and a fourth sensor,
the first sensor being located at a first sensor location and the second sensor being located at a second sensor location, situated on a first virtual line oriented in the first direction, and spaced apart from each other by a first distance,
the first sensor being configured for measuring a first magnetic field component oriented in the first direction and a second magnetic field component oriented in the third direction,
the second sensor being configured for measuring a third magnetic field component oriented in the first direction and a fourth magnetic field component oriented in the third direction;
the third sensor being located at a third sensor location and the fourth sensor being located at a fourth sensor location, situated on a second virtual line oriented in the second direction, and spaced apart from each other by a second distance,
the third sensor being configured for measuring a fifth magnetic field component oriented in the second direction and a sixth magnetic field component oriented in the third direction,
the fourth sensor being configured for measuring a seventh magnetic field component oriented in the first direction and an eighth magnetic field component oriented in the third direction.

3. The sensor device according to claim 1 , wherein the first angle is determined in accordance with the formula:
α= K 1* a tan 2( dBz/dx,dBx/dx ),

wherein α is the first angle, a tan 2( ) is the two-argument arctangent function, dBx/dx is the first magnetic field gradient, and dBz/dx is the third magnetic field gradient, and K1 is a first predefined constant; and
wherein the second angle is determined in accordance with the formula:
β= K 2* a tan 2( dBz/dy,dBy/dy ),

wherein β is the second angle, a tan 2( ) is the two-argument arctangent function, dB y/dy is the second magnetic field gradient, dBz/dy is the fourth magnetic field gradient, and K2 is a second predefined constant.

4. The sensor device according to claim 1 , wherein the first angle is determined in accordance with the formula:
α= K 1* a tan 2( K 3* dBz/dx,dBx/dx ),

wherein α is the first angle, a tan 2( ) is the two-argument arctangent function, dBx/dx is the first magnetic field gradient, dBz/dx is the third magnetic field gradient, and K1 and K3 are predefined constants; and
wherein the second angle is determined in accordance with the formula:
β= K 2* a tan 2( K 4* dBz/dy,dBy/dy ),

wherein β is the second angle, a tan 2( ) is the two-argument arctangent function, dB y/dy is the second magnetic field gradient, dBz/dy is the fourth magnetic field gradient, and K2 and K4 are predefined constants.

5. The sensor device according to claim 1 , wherein the magnet is movable such that a virtual axis of the magnet is pivotable about a reference point having a predefined position relative to the semiconductor substrate.

6. The sensor device according to claim 1 , wherein a first distance between the first sensor location and the second sensor location is substantially equal to a second distance between the third sensor location and the fourth sensor location; or
wherein a first distance between the first sensor location and the second sensor location is at least 5% larger or at least 5% smaller than a second distance between the third sensor location and the fourth sensor location.

7. The sensor device according to claim 1 , wherein each of the four sensors comprises an integrated magnetic concentrator and two horizontal Hall elements.

8. The sensor device according to claim 1 , wherein each of the four sensors comprises a horizontal Hall element and a vertical Hall element; or
wherein each of the four sensors comprises a horizontal Hall element and at least one magneto-resistive sensor element.

9. The sensor device according to claim 1 , wherein the processing circuit is integrated in the semiconductor substrate.

10. A position sensor system comprising:
a sensor device according to claim 1 , the sensor device comprising a semiconductor substrate; and
a magnet pivotable about a reference point having a predefined position relative to the semiconductor substrate.

11. The position sensor system according to claim 10 , wherein the system further comprises a joystick connected to the magnet.

12. A method of determining a first and a second angle indicative of an orientation of a magnet which is pivotable about a reference point having a predefined position relative to a semiconductor substrate, the method comprising:
a) determining at least iii) and iv) of the following magnetic field gradients:
i) a first magnetic field gradient of a first magnetic field component oriented in a first direction parallel to a semiconductor substrate along said first direction;
ii) a second magnetic field gradient of a second magnetic field component oriented in a second direction parallel to the semiconductor substrate and perpendicular to the first direction, along said second direction;
iii) a third magnetic field gradient of a third magnetic field component oriented in a third direction perpendicular to the first direction along said first direction;
iv) a fourth magnetic field gradient of the third magnetic field component oriented in a fourth direction perpendicular to the second direction along said second direction;

b) determining said first angle formed between an orthogonal projection of the axis of the magnet on a first virtual plane parallel to the first direction and the third direction, based on at least the third magnetic field gradient; and
c) determining said second angle formed between an orthogonal projection of the axis of the magnet on a second virtual plane parallel to the second direction and the third direction, based on at least the fourth magnetic field gradient.

13. The method according to claim 12 , wherein the first angle is determined in accordance with the formula:
α= K 1* a tan 2( dBz/dx,dBx/dx ),

wherein α is the first angle, a tan 2( ) is the two-argument arctangent function, dBx/dx is the first magnetic field gradient, dBz/dx is the third magnetic field gradient, and K1 is a first predefined constant; and
wherein the second angle is determined in accordance with the formula:
β= K 2* a tan 2( dBz/dy,dBy/dy ),

Assignees

• Melexis Tech Sa

Inventors

• Close Gael
• Dupre Nicolas
• Depoorter Jean-Claude
• Bidaux Yves

Classifications

• G01R33/10 Primary

  Plotting field distribution {; Measuring field distribution} · CPC title

• G05G9/047

  the controlling member being movable by hand about orthogonal axes, e.g. joysticks {(for switches H01H25/04)} · CPC title

• G01R33/0005 Primary

  Geometrical arrangement of magnetic sensor elements; Apparatus combining different magnetic sensor types (G01R33/0206 takes precedence) · CPC title

• G01D5/145 Primary

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

• G01R33/02

  Measuring direction or magnitude of magnetic fields or magnetic flux (G01R33/20 takes precedence) · CPC title