INDUCTIVE SENSOR

• US 20140132253A1
• Filed: 11/13/2013
• Published: 05/15/2014
• Est. Priority Date: 11/13/2012
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: Bertin, Jacques
• Granted Patent: US 9,528,858 B2
• Time in Patent Office: Days
• US Class Current: 324/207.17
• CPC Class Codes: G01D 5/2053 by a movable non-ferromagnetic conductive element
• CPC Class Codes: G01D 5/2086 by movement of two or more coils with respect to two or more other coils

Abstract

In one embodiment, an electronic device includes an excitation control; a first excitation element coupled to the excitation control; a second excitation element coupled to the excitation control; a target positioned near the first and second excitation elements and within the electromagnetic fields generated by the first and second excitation elements; a receiving element positioned near the target and within the electromagnetic fields generated by the first and second excitation elements; and a signal processor coupled to the receiving element and coupled to the excitation control.

Claims

1. An electronic device comprising:

an excitation control configured to receive a variable first parameter and configured to generate a first signal as a function of the variable first parameter and a second signal as a function of the variable first parameter;

a first excitation element coupled to the excitation control and configured to receive the first signal and configured to generate a corresponding first electromagnetic field;

a second excitation element coupled to the excitation control and configured to receive the second signal and configured to generate a corresponding second electromagnetic field;

a target positioned within the first and second electromagnetic fields and configured to alter the first and second electromagnetic fields as a function of its angular position;

a receiving element positioned within the first and second electromagnetic fields and coupled to the first and second excitation elements and configured to generate a third signal in response to the first and second electromagnetic fields as altered by the target; and

a signal processor coupled to the receiving element and coupled to the excitation control, wherein the signal processor is configured to receive the third signal and provide an updated variable first parameter to the excitation control, and wherein the signal processor is also configured to generate a fourth signal representing the angular position of the target based on the third signal and the variable first parameter.

2. The electronic device of claim 1, wherein the receiving element is coupled to the first and second excitation elements via electromagnetic induction.

3. The electronic device of claim 1, wherein there is only one receiving element.

4. The electronic device of claim 1, wherein the first and second excitation elements comprise electrically conductive traces comprising lines and curves having periodic bends.

5. The electronic device of claim 1, wherein the receiving element comprises a planar spiral conductive trace.

6. The electronic device of claim 1, further comprising a third excitation element coupled to the excitation control and configured to receive a fifth signal and generate a corresponding third electromagnetic field, and wherein the excitation control is further configured to generate a fifth signal as a function of the variable first parameter, and wherein the target is also positioned within the third electromagnetic field and is also configured to alter the third electromagnetic field as a function of its angular position, and wherein the receiving element is positioned within the third electromagnetic field and configured to generate a signal in response to electromagnetic induction by the first, second and third electromagnetic fields.

7. A vehicle, comprising:

a printed circuit board within the vehicle;

an first excitation element coupled to the printed circuit board and capable of receiving a first signal and generating a first electromagnetic field;

a second excitation element coupled to the printed circuit board and capable of receiving a second signal and generating a second electromagnetic field;

a rotor within the vehicle that is rotatable relative to the first and second excitation elements and capable of affecting the first and second electromagnetic fields as a function of an angular position of the rotor relative to the first and second excitation elements;

a receiving element coupled to the printed circuit board and capable of generating a third signal in response to the first and second electromagnetic fields as affected by the angular position of the rotor; and

a signal processor coupled to the receiving element and capable of evaluating a first value of the third signal generated by the receiving element, providing an adjustment to the first and second signals, and determining the angular position of the rotor.

8. The vehicle of claim 7, wherein there is only one receiving element.

9. The vehicle of claim 7, wherein the first and second excitation elements comprise electrically conductive traces having periodic bends.

10. The vehicle of claim 7, wherein the receiving element comprises a planar spiral conductive trace.

11. The vehicle of claim 7, wherein the printed circuit board comprises a multilayer printed circuit board

12. The vehicle of claim 7, further comprising a third excitation element coupled to the printed circuit board and capable of receiving a fourth signal and generating a third electromagnetic field, and wherein the rotor is also capable of affecting the third electromagnetic field as a function of the angular position of the rotor, and wherein the third signal is generated in response to the first, second, and third electromagnetic fields as affected by the angular position of the rotor, and wherein the signal processor is also capable of providing an adjustment to the fourth signal.

13. An electronic device comprising:

a plurality of excitation elements having a common shape and configured to generate electromagnetic fields;

a coupler element positioned within the electromagnetic fields and configured to alter the electromagnetic fields as a function of the angular position of the coupler element, and wherein a shape of the coupler element substantially matches the common shape of the excitation elements; and

a receiving element configured to generate a signal in response to the electromagnetic fields as altered by the coupler element, wherein a value of the signal represents an approximate angular position of the coupler element.

14. The electronic device of claim 13, wherein there is only one receiving element.

15. The electronic device of claim 13, wherein the plurality of excitation elements comprise conductive planar windings on a printed circuit board.

16. The electronic device of claim 13, wherein the plurality of excitation elements comprise conductive planar windings with periodic bends.

17. The electronic device of claim 13, wherein the receiving element comprises a conductive planar winding on a printed circuit board.

18. The electronic device of claim 13, wherein the receiving element comprises a conductive planar winding in a spiral shape.

19. A method for sensing an angular position of a target element, comprising:

providing a first signal to a first excitation element and inducing a first electromagnetic field;

providing a second signal to a second excitation element and inducing a second electromagnetic field;

altering the first and second electromagnetic fields with the target element, wherein the target element is configured to alter the first and second electromagnetic fields as a function of the angular position of the target element;

generating a third signal in a receiving element by coupling the receiving element with the altered first and second electromagnetic fields;

evaluating a first value of the third signal;

providing an adjustment to the first and second signals if the first value of the third signal is outside of a first set range; and

outputting a fourth signal if the first value of the third signal is within the first set range, wherein the fourth signal represents the angular position of a target element.

20. A method for sensing an angular position of a target element, comprising:

providing a first signal to a first excitation element and inducing a first electromagnetic field;

providing a second signal to a second excitation element and inducing a second electromagnetic field;

altering the first and second electromagnetic fields with the target element, wherein the target element is configured to alter the first and second electromagnetic fields as a function of the angular position of the target element;

generating a third signal in a receiving element by coupling the receiving element with the altered first and second electromagnetic fields;

evaluating a first value of the third signal;

providing a sampling adjustment to the first and second signals and evaluating an adjusted first value of the third signal; and

calculating and outputting a fourth signal based on the first value of the third signal and the adjusted first value of the third signal, wherein the fourth signal represents the angular position of the target element.