Magnetic sensing system and method

• US 7,463,987 B2
• Filed: 09/26/2006
• Issued: 12/09/2008
• Est. Priority Date: 09/19/2003
• Status: Expired due to Fees

• Current Assignee: Takara Holdings Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Takara Holdings Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Stanley, James Gregory, Cech, Leonard S., Bomya, Timothy J.
• Primary Examiner(s): TSAI, CAROL S W
• Application Number:
  US11/535,481
• Publication Number:
  US 20070118312A1
• Time in Patent Office: 805 Days
• Field of Search: 702/65, 702/190, 324/251, 324/207.2, 324/207.13, 324/207.17, 324/228, 324/207.16, 340/573.1, 340/436, 340/547, 340/540, 280/734, 280/735, 307/10.1, 307/9.1, 738/626.9, 180/273
• US Class Current: 702/65
• CPC Class Codes: B60R 2021/0006 Lateral collision
• CPC Class Codes: B60R 2021/01027 Safing sensors
• CPC Class Codes: B60R 2021/01197 Warning devices
• CPC Class Codes: B60R 21/0134 responsive to imminent contact with an obstacle , e.g. using radar systems
• CPC Class Codes: B60R 21/0136 responsive to actual contact with an obstacle , e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle monitoring crash strength in combination with passenger seat detection B60R21/01558

Abstract

A coil at a first location in magnetic communication with a door of a vehicle generates a magnetic field responsive to a time varying signal applied thereto. The first location and the coil are adapted so that the magnetic field is influenced by an opening state of the door, and by a crash involving the door. A signal is generated from the coil responsive to the time-varying signal and to the magnetic field, wherein the signal provides for sensing an opening state of the door and for sensing a crash involving the door.

Claims

1. A method of sensing a magnetic condition of a door of a vehicle, comprising:

a. locating at least one first coil at at least one first location in magnetic communication with a first door of the vehicle;

b. applying at least one first time-varying signal to said at least one first coil;

c. generating at least one first magnetic field with said at least one first coil responsive to said at least one first time-varying signal, wherein at least a portion of said at least one first magnetic field is in magnetic communication with said first door, said at least one first location and said at least one first coil are adapted so that said at least one first magnetic field is influenced by an opening state of said first door, and said at least one first location and said at least one first coil are adapted so that said at least one first magnetic field is influenced by a crash involving said first door; and

d. generating at least one first signal from said at least one first coil responsive to said at least one first time-varying electrical signal and responsive to at least said at least one first magnetic field, wherein said at least one first signal provides for sensing an opening state of said first door, and said at least one first signal provides for sensing a crash involving said first door.

2. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 1, wherein said at least one first magnetic field provides both for sensing said opening state of said first door and for sensing said crash involving said first door.

3. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 1, wherein said at least one first signal is responsive to a self-impedance of said at least one first coil.

4. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 3, wherein said at least one first signal is responsive to a self-inductance of said at least one first coil.

5. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 3, wherein said at least one first signal comprises a first signal component that is substantially in-phase with respect to said at least one first time-varying signal.

6. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 5, wherein said first signal component is responsive to at least one eddy current induced in at least a portion of said first door by said at least one first magnetic field.

7. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 1, wherein said at least one first time-varying signal is applied in a burst mode so as to conserve power.

8. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 6, wherein said at least one first time-varying signal is applied for a sufficient number of consecutive cycles so as to provide for a detection of said at least one first signal, followed by a substantial dwell period.

9. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 7, wherein a length of said dwell period is adapted so that a duty cycle of said at least one first time-varying signal is less than 0.1 percent.

10. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 7, wherein said at least one first time-varying signal is applied to said at least one first coil even when said vehicle is in a quiescent state.

11. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 1, further comprising:

a. locating at least one second coil at a corresponding at least one second location in magnetic communication with said first door;

b. applying at least one second time-varying signal to said at least one second coil; and

c. generating at least one second magnetic field with said at least one second coil responsive to said at least one second time-varying signal, wherein at least a portion of said at least one second magnetic field is in magnetic communication with said first door, said first and second locations and said at least one first and second coils are adapted so that said at least one second magnetic field is influenced by a crash involving said first door, wherein said at least one first signal comprises at least one first component and at least one second component, said at least one first component of said at least one first signal is responsive to said at least one first time-varying electrical signal and responsive to said at least one first magnetic field, and provides for sensing said opening state of said first door, and said at least one second component of said at least one first signal is responsive to said at least one second magnetic field, and provides for sensing said crash involving said first door.

12. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 11, wherein said first and second time-varying signals are operated mutually exclusively in time.

13. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 11, wherein said first and second time-varying signals are operated at different frequencies.

14. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 1, wherein said at least one first location is proximate to a first pillar of the vehicle, wherein an edge of said first door is adapted to swing away from said pillar when said first door is opened.

15. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 14, further comprising a first control operation comprising controlling at least a first safety restraint actuator of said vehicle responsive to said at least one first signal.

16. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 15, further comprising:

a. locating at least third coil at at least one third location in magnetic communication with a second door of said vehicle, wherein said at least one third location is proximate to a second pillar of said vehicle, wherein an edge of said second door is adapted to swing away from said pillar when said second door is opened, and said first and second doors are on a same side of said vehicle

b. applying at least one third time-varying signal to said at least one third coil;

c. generating at least one third magnetic field with said at least one third coil responsive to said at least one third time-varying signal, wherein at least a portion of said at least one third magnetic field is in magnetic communication with said second door, said at least one third location and said at least one third coil are adapted so that said at least one third magnetic field is influenced by an opening state of said second door, and said at least one third location and said at least one third coil are adapted so that said at least one third magnetic field is influenced by a crash involving said second door;

d. generating at least one second signal from said at least one third coil responsive to said at least one third time-varying electrical signal and responsive to at least said at least one third magnetic field, wherein said at least one second signal provides for sensing an opening state of said second door, and said at least one second signal provides for sensing a crash involving said second door;

e. a second control operation comprising controlling at least one of said first or another safety restraint actuator of said vehicle responsive to said at least one second signal;

f. safing said first control operation responsive to said at least one second signal, and

g. safing the control of said second control operation responsive to said at least one first signal.

17. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 15, further comprising sensing an acceleration of the vehicle at a location in or proximate to said first door, and safing said first control operation responsive to the operation of sensing said acceleration of said vehicle at said location in or proximate to said first door.

18. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 15, further comprising:

a. locating at least fourth coil at at least one fourth location in magnetic communication with said first door of said vehicle, wherein said at least one fourth location is proximate to said first pillar of said vehicle;

b. applying at least one fourth time-varying signal to said at least one fourth coil;

c. generating at least one fourth magnetic field with said at least one fourth coil responsive to said at least one fourth time-varying signal, wherein at least a portion of said at least one fourth magnetic field is in magnetic communication with said first door, and said at least one fourth location and said at least one fourth coil are adapted so that said at least one fourth magnetic field is influenced by an opening state of said first door;

d. generating at least one third signal from said at least one fourth coil responsive to said at least one fourth time-varying electrical signal and responsive to at least said at least one fourth magnetic field, wherein said at least one third signal provides for sensing an opening state of said first door; and

e. safing said first control operation responsive to said at least one third signal.

19. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 1, further comprising adjusting at least one detection threshold for sensing said opening state of said first door when said first door is in at least one known state of opening.

20. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 1, further comprising controlling an actuation of an interior light of said vehicle response to said at least one first signal.

21. A method of sensing a magnetic condition of a door of a vehicle as recited in claim 1, further comprising communicating said at least one first signal to a vehicle security system.