Device and method for determining an orientation of a magnet, and a joystick
AssigneeMelexis Technologies SA
InventorsLionel Tombez, Nicolas Dupre, Eric Lahaye
Life of this patent
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Abstract
A method of determining an orientation of a magnet which is pivotable about a reference position having a predefined position relative to a silicon substrate, includes: providing a silicon substrate; determining a first/second magnetic field gradient along a first/second direction; determining a first/second angle based on said first/second magnetic field gradient and a first/second correction value. A sensor device configured for performing this method. A sensor system includes such sensor device and a magnet, optionally connected to a joystick.
Claims14
A sensor device for determining an orientation of a magnet having an axis, the sensor device comprising:
- a silicon substrate comprising a plurality of magnetic sensors;
- a processing circuit configured for:
- a) determining a first magnetic field gradient (dBz/dx) of a first magnetic field component (Bz) oriented in a third direction (Z) perpendicular to said silicon substrate, along a first direction (X) parallel to the silicon substrate;
- b) determining a second magnetic field gradient (dBz/dy) of said first magnetic field component (Bz) oriented in the third direction (Z) perpendicular to said silicon substrate, along a second direction (Y) parallel to the silicon substrate and perpendicular to the first direction (X);
- c) determining a first angle as a function of said first magnetic field gradient (dBz/dx) and a first correction value;
- d) determining a second angle as a function of said second magnetic field gradient (dBz/dy) and a second correction value.
A sensor device for determining an orientation of a magnet having an axis, the sensor device comprising:
- a silicon substrate comprising a plurality of magnetic sensors;
- a processing circuit configured for:
- a) determining a first magnetic field gradient (dBx/dx;
- dBz/dx) of a first magnetic field component (Bx;
- Bz) oriented in a first direction (X) parallel to the silicon substrate or oriented in a third direction (Z) perpendicular to said silicon substrate, along said first direction (X);
- b) determining a second magnetic field gradient (dBy/dy;
- dBz/dy) of a second magnetic field component (By;
- Bz) oriented in a second direction (Y) parallel to the silicon substrate and perpendicular to the first direction (X) or oriented in the third direction (Z) perpendicular to said silicon substrate, along said second direction (Y);
- c) determining a first angle as a function of said first magnetic field gradient (dBx/dx;
- dBz/dx) and a first correction value;
- d) determining a second angle as a function of said second magnetic field gradient (dBy/dy;
- dBz/dy) and a second correction value;
- wherein the sensor device is further configured for determining a second order gradient (d2Bx/dx2;
- d2Bz/dx2) of the first magnetic field component (Bx;
- Bz) along the first direction (X), and for determining a second order gradient (d2By/dy2;
- d2Bz/dy2) of the second magnetic field component (By;
- Bz) along the second direction (Y);
- and
- wherein step c) comprises:
- determining the first angle as a function of said first magnetic field gradient (dBx/dx;
- dBz/dx) and said second order gradient (d2Bx/dx2;
- d2Bz/dx2) of the first magnetic field component (Bx;
- Bz) along the first direction (X);
- and
- wherein step d) comprises:
- determining the second angle as a function of said second magnetic field gradient (dBy/dy;
- dBz/dy) and said second order gradient (d2By/dy2;
- d2Bz/dy2) of the second magnetic field component (By;
- Bz) along the second direction (Y).
A method of determining an orientation of a magnet which is pivotable about a reference point having a predefined position relative to a silicon substrate, the method comprising:
- a) providing a silicon substrate comprising a plurality of magnetic sensors, and measuring a plurality of magnetic field components at a plurality of sensor locations;
- b) determining a first magnetic field gradient (dBz/dx) of a first magnetic field component (Bz) oriented in a third direction (Z) perpendicular to said silicon substrate, along a first direction (X) parallel to the silicon substrate;
- c) determining a second magnetic field gradient (dBz/dy) of a second magnetic field component (Bz) oriented in the third direction (Z), along a second direction (Y) parallel to the silicon substrate and perpendicular to the first direction (X);
- d) determining a first angle formed between an orthogonal projection of an axis of the magnet on a first virtual plane (XZ) parallel to the first direction (X) and the third direction (Z), as a function of said first magnetic field gradient (dBz/dx) and a first correction value;
- e) determining a second angle formed between an orthogonal projection of the axis (A) of the magnet on a second virtual plane (YZ) parallel to the second direction (Y) and the third direction (Z), as a function of said second magnetic field gradient (dBz/dy) and a second correction value.
A method of determining an orientation of a magnet which is pivotable about a reference point having a predefined position relative to a silicon substrate, the method comprising:
- a) providing a silicon substrate comprising a plurality of magnetic sensors, and measuring a plurality of magnetic field components at a plurality of sensor locations;
- b) determining a first magnetic field gradient (dBx/dx;
- dBz/dx) of a first magnetic field component (Bx;
- Bz) oriented in a first direction (X) parallel to a silicon substrate or oriented in a third direction (Z) perpendicular to said substrate, along said first direction X
- c) determining a second magnetic field gradient (dBy/dy;
- dBz/dy) of a second magnetic field component (By;
- Bz) oriented in a second direction (Y) parallel to the silicon substrate and perpendicular to the first direction (X) or oriented in the third direction (Z), along said second direction (Y);
- d) determining a first angle formed between an orthogonal projection of the axis of the magnet on a first virtual plane (XZ) parallel to the first direction (X) and the third direction (Z), as a function of said first magnetic field gradient (dBx/dx or dBz/dx) and a first correction value;
- e) determining a second angle formed between an orthogonal projection of the axis (A) of the magnet on a second virtual plane (YZ) parallel to the second direction (Y) and the third direction (Z), as a function of said second magnetic field gradient (dBy/dy or dBz/dy) and a second correction value;
- wherein the method further comprises:
- determining a second order gradient (d2Bx/dx2;
- d2Bz/dx2) of the first magnetic field component (Bx;
- Bz) along the first direction (X);
- and
- wherein the method further comprises:
- determining a second order gradient (d2By/dy2;
- d2Bz/dy2) of the second magnetic field component (By;
- Bz) along the second direction (Y);
- and
- wherein step d) comprises:
- determining the first angle as a function of said first magnetic field gradient (dBx/dx;
- dBz/dx) and said second order gradient (d2Bx/dx2;
- d2Bz/dx2) of the first magnetic field component (Bx;
- Bz) along the first direction (X);
- and
- wherein step e) comprises:
- determining the second angle as a function of said second magnetic field gradient (dBy/dy;
- dBz/dy) and said second order gradient (d2By/dy2;
- d2Bz/dy2) of the second magnetic field component (By;
- Bz) along the second direction (Y).
Dependencies are inferred from the claim text.