INTEGRATED AUTOMATIC COMPASS FOR VEHICLE

• US 20140097832A1
• Filed: 12/16/2013
• Published: 04/10/2014
• Est. Priority Date: 06/06/2002
• Status: Active Grant

• Current Assignee: Donnelly Corporation (Magna International Incorporated)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Blank, Rodney K., Schierbeek, Kenneth L., Lynam, Niall R.
• Granted Patent: US 8,777,431 B2
• Time in Patent Office: Days
• US Class Current: 324/207.21
• CPC Class Codes: B60R 1/12 Mirror assemblies combined with other articles, e.g. clocks
• CPC Class Codes: B60R 2001/1215 with information displays
• CPC Class Codes: G01C 17/28 Electromagnetic compasses with north seeking magnetic elements and having electric pick-offs G01C17/26
• CPC Class Codes: G01C 17/38 Testing, calibrating, or compensating of compasses

Abstract

An integrated automotive compass suitable for use in a vehicle includes an application specific integrated circuit that includes at least first and second magnetoresponsive sensing elements. The first and second magnetoresponsive sensing elements and at least a portion of associated circuitry are established on a common semiconductor substrate using CMOS technology. When powered via a vehicle power source, the application specific integrated circuit, at least in part, generates a compass directional heading of the vehicle. The directional heading of the vehicle is determined, at least in part, responsive to a sensing of a magnetic field by the magnetoresponsive sensing elements. Automatic compensation for a deviating magnetic field during operation of the vehicle is achieved, at least in part, via an algorithm processed by a processor of application specific integrated circuit.

Claims

1. An integrated automotive compass suitable for use in a vehicle, said integrated automotive compass comprising:

an application specific integrated circuit;

said application specific integrated circuit comprising at least first and second magnetoresponsive sensing elements;

wherein said first and second magnetoresponsive sensing elements and at least a portion of associated circuitry are established on a common semiconductor substrate using CMOS technology;

wherein said associated circuitry comprises at least one of (i) an A/D converter, (ii) a D/A converter, (iii) signal processing circuitry, (iv) memory, (v) signal filtering circuitry, (vi) a display driver, (vii) a LIN bus interface and (viii) a CAN bus interface;

wherein said application specific integrated circuit occupies a less than about two square centimeter area;

wherein, when powered via a vehicle power source, said application specific integrated circuit, at least in part, generates a compass directional heading of a vehicle equipped with said application specific integrated circuit;

wherein said directional heading of the equipped vehicle is determined, at least in part, responsive to a sensing of a magnetic field by said magnetoresponsive sensing elements; and

wherein automatic compensation for a deviating magnetic field during operation of the equipped vehicle is achieved, at least in part, via an algorithm processed by a processor of said application specific integrated circuit.

2. The integrated automotive compass of claim 1, wherein said application specific integrated circuit comprises first, second and third magnetoresponsive sensing elements.

3. The integrated automotive compass of claim 2, wherein said first and second magnetoresponsive sensing elements are disposed generally orthogonally to each other and wherein said third magnetoresponsive sensing element is disposed generally orthogonally to said first and second magnetoresponsive sensing elements.

4. The integrated automotive compass of claim 1, wherein said magnetoresponsive sensing elements comprise Hall effect magnetoresponsive sensing elements.

5. The integrated automotive compass of claim 1, wherein said application specific integrated circuit is disposed at an interior rearview mirror assembly of the equipped vehicle.

6. The integrated automotive compass of claim 5, wherein said application specific integrated circuit is disposed in a mirror casing of said interior rearview mirror assembly that is adjustable by a driver of the equipped vehicle.

7. The integrated automotive compass of claim 6, wherein an algorithm processed by said processor of said application specific integrated circuit discerns between a change in said sensing by said magnetoresponsive sensing elements that is indicative of an adjustment of said mirror casing by the driver of the equipped vehicle and a change in said sensing by said magnetoresponsive sensing elements that is indicative of a change in vehicle direction, and causes said automatic compass system to enter a rapid compensating mode when the change in said sensing by said magnetoresponsive sensing elements is indicative of an adjustment of said mirror casing by the driver of the equipped vehicle.

8. The integrated automotive compass of claim 1, wherein an algorithm processed by said processor of said application specific integrated circuit enters an initial rapid compensating mode in response to an ignition cycle of the equipped vehicle to achieve at least an approximate compensation for a deviating magnetic field of the equipped vehicle, and wherein said rapid compensating mode is automatically exited and a less aggressive calibration mode is entered that distinguishes the Earth'"'"'s magnetic field from magnetic anomalies and changes in the vehicle magnetic signature.

9. The integrated automotive compass of claim 8, wherein said rapid compensating mode is automatically exited after a predetermined period of time has elapsed since the ignition cycle.

10. The integrated automotive compass of claim 1, wherein said algorithm processed by said processor of said application specific integrated circuit automatically compensates for a deviating magnetic field of the equipped vehicle and wherein automatic compensation does not require the equipped vehicle to turn through 360 degrees.

11. The integrated automotive compass of claim 1, wherein said application specific integrated circuit further comprises a temperature sensor and wherein said temperature sensor is commonly established with said magnetoresponsive sensing elements.

12. The integrated automotive compass of claim 1, wherein said common semiconductor substrate comprises a silicon substrate.

13. An integrated automotive compass suitable for use in a vehicle, said integrated automotive compass comprising:

an application specific integrated circuit;

said application specific integrated circuit comprising at least first and second magnetoresponsive sensing elements;

wherein said first and second magnetoresponsive sensing elements and at least a portion of associated circuitry are established on a common semiconductor substrate using CMOS technology;

wherein said first and second magnetoresponsive sensing elements are disposed generally orthogonally to each other;

wherein, when powered via a vehicle power source, said application specific integrated circuit, at least in part, generates a compass directional heading of a vehicle equipped with said application specific integrated circuit;

wherein said directional heading of the equipped vehicle is determined, at least in part, responsive to a sensing of a magnetic field by said magnetoresponsive sensing elements;

wherein automatic compensation for a deviating magnetic field during operation of the equipped vehicle is achieved, at least in part, via an algorithm processed by a processor of said application specific integrated circuit; and

wherein said algorithm processed by said processor of said application specific integrated circuit automatically compensates for a deviating magnetic field of the equipped vehicle.

14. The integrated automotive compass of claim 13, wherein at least one of (i) automatic compensation does not require the equipped vehicle to turn through 360 degrees and (ii) said application specific integrated circuit occupies a less than about two square centimeter area.

15. The integrated automotive compass of claim 13, wherein said associated circuitry comprises at least one of (i) an A/D converter, (ii) a D/A converter, (iii) signal processing circuitry, (iv) memory, (v) signal filtering circuitry, (vi) a display driver, (vii) a LIN bus interface and (viii) a CAN bus interface.

16. The integrated automotive compass of claim 13, wherein said application specific integrated circuit is disposed at an interior rearview mirror assembly of the equipped vehicle, and wherein said application specific integrated circuit is disposed in a mirror casing of said interior rearview mirror assembly that is adjustable by a driver of the equipped vehicle.

17. An integrated automotive compass suitable for use in a vehicle, said integrated automotive compass comprising:

an application specific integrated circuit;

said application specific integrated circuit comprising at least first and second magnetoresponsive sensing elements;

wherein said first and second magnetoresponsive sensing elements and at least a portion of associated circuitry are established on a common semiconductor substrate using CMOS technology;

wherein said first and second magnetoresponsive sensing elements are disposed generally orthogonally to each other;

wherein said associated circuitry comprises at least one of (i) an A/D converter, (ii) a D/A converter, (iii) signal processing circuitry, (iv) memory, (v) signal filtering circuitry, (vi) a display driver, (vii) a LIN bus interface and (viii) a CAN bus interface;

wherein, when powered via a vehicle power source, said application specific integrated circuit, at least in part, generates a compass directional heading of a vehicle equipped with said application specific integrated circuit;

wherein said directional heading of the equipped vehicle is determined, at least in part, responsive to a sensing of a magnetic field by said magnetoresponsive sensing elements; and

wherein automatic compensation for a deviating magnetic field during operation of the equipped vehicle is achieved, at least in part, via an algorithm processed by a processor of said application specific integrated circuit.

18. The integrated automotive compass of claim 17, wherein said application specific integrated circuit is disposed at an interior rearview mirror assembly of the equipped vehicle, and wherein said application specific integrated circuit is disposed in a mirror casing of said interior rearview mirror assembly that is adjustable by a driver of the equipped vehicle.

19. The integrated automotive compass of claim 17, wherein at least one of (a) an algorithm processed by said processor of said application specific integrated circuit automatically compensates for a deviating magnetic field of the equipped vehicle, (b) an algorithm processed by said processor of said application specific integrated circuit automatically compensates for a deviating magnetic field of the equipped vehicle and wherein automatic compensation does not require the equipped vehicle to turn through 360 degrees, and (c) wherein said application specific integrated circuit occupies a less than about two square centimeter area.

20. The integrated automotive compass of claim 17, wherein an algorithm processed by said processor of said application specific integrated circuit enters an initial rapid compensating mode in response to an ignition cycle of the equipped vehicle to achieve at least an approximate compensation for a deviating magnetic field of the equipped vehicle, and wherein said rapid compensating mode is automatically exited and a less aggressive calibration mode is entered that distinguishes the Earth'"'"'s magnetic field from magnetic anomalies and changes in the vehicle magnetic signature.