Eddy current magnetic crash sensor

• US 7,839,143 B2
• Filed: 10/31/2007
• Issued: 11/23/2010
• Est. Priority Date: 09/19/2003
• Status: Expired due to Fees

• Current Assignee: Joyson Safety Systems Acquisition, LLC (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: TK Holdings Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Cech, Leonard S., Aoki, Hiroshi, Watson, William Todd
• Primary Examiner(s): WHITTINGTON, KENNETH
• Application Number:
  US11/930,142
• Publication Number:
  US 20080211646A1
• Time in Patent Office: 1,119 Days
• Field of Search: 324/209, 324/229, 324/233, 324/236, 324/239, 324/240, 324/207.13, 324/207.16, 324/207.17, 340/551, 340/436, 340/435, 340/438, 180/274, 280/734, 280/735
• US Class Current: 324/228
• 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

At least one time-varying signal is applied to a plurality of coil elements in cooperative relationship with and spanning different portions of a vehicle. The coil elements generate an associated plurality of magnetic field components that interact with the vehicle. At least one detection circuit generates a detected signal responsive to signal components from the coil elements so as to provide for detecting a change in a magnetic condition of the vehicle.

Claims

1. A method of detecting a change in a magnetic condition of a vehicle, comprising:

a. generating a first time-varying magnetic field component proximate to a first portion of the vehicle at a first location;

b. generating at least one second time-varying magnetic field component proximate to at least one second portion of said vehicle at at least one corresponding second location, wherein said at least one corresponding second location is separated from said first location, said first portion of said vehicle and said at least one second portion of said vehicle are at least partially conductive so that said first time-varying magnetic field component generates a corresponding first eddy current component in said first portion of said vehicle, said at least one second time-varying magnetic field component generates a corresponding at least one second eddy current component in said at least one second portion of said vehicle, and said first location and at least one of said at least one corresponding second location are each proximally adjacent to corresponding separate conductive portions of a common surface of said vehicle; and

c. detecting a change in the magnetic condition of said vehicle responsive to a first signal responsive to said corresponding first eddy current component, and responsive to at least one second signal responsive to said corresponding at least one second eddy current component.

2. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, wherein said first location and said at least one corresponding second location span a substantial region of a body or structural element of said vehicle, wherein said body or structural element of said vehicle is susceptible to deformation responsive to a crash.

3. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, further comprising shaping, controlling or limiting at least one of said first time-varying magnetic field component and said at least one second time-varying magnetic field component with at least one proximal conductive element.

4. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 3, wherein the operation of shaping, controlling or limiting at least one of said first time-varying magnetic field component and said at least one second time-varying magnetic field component comprises configuring said at least one proximal conductive element so as to control or mitigate against eddy currents therein.

5. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, wherein the operation of generating said first time-varying magnetic field component comprises operatively coupling a first time-varying voltage source to a first coil, the operation of generating said at least one second time-varying magnetic field component comprises operatively coupling either said first time-varying voltage source or at least one second time-varying voltage source to at least one second coil, and the operation of detecting said change in said magnetic condition of said vehicle comprises detecting at least one current signal in at least one of said first coil and said at least one second coil.

6. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, wherein the operation of generating said first time-varying magnetic field component comprises operatively coupling a first time-varying signal source to a first coil, the operation of generating said at least one second time-varying magnetic field component comprises operatively coupling either said first time-varying signal source or at least one second time-varying signal source to at least one second coil, and said first time-varying signal source and said at least one second time-varying signal source provide for generating at least one oscillatory waveform selected from a sinusoid waveform, a triangular ramped waveform, a triangular saw tooth waveform, and a square waveform.

7. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, wherein the operation of generating said first time-varying magnetic field component comprises operatively coupling a first time-varying signal source to a first coil, the operation of generating said at least one second time-varying magnetic field component comprises operatively coupling either said first time-varying signal source or at least one second time-varying signal source to at least one second coil, and said first time-varying signal source and said at least one second time-varying signal source provide for generating at least one oscillatory waveform comprising a plurality of different frequencies.

8. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, wherein the operation of generating said first time-varying magnetic field component comprises operatively coupling a first time-varying signal source to a first coil, the operation of generating said at least one second time-varying magnetic field component comprises operatively coupling either said first time-varying signal source or at least one second time-varying signal source to at least one second coil, and said first time-varying signal source and said at least one second time-varying signal source provide for generating at least one pulsed waveform.

9. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 8, wherein said at least one pulsed waveform comprises at least one shape of either a ramp, a saw tooth, an impulse or a rectangle.

10. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, wherein the operation of generating said first time-varying magnetic field component comprises operatively coupling a first time-varying signal source to a first coil, the operation of generating said at least one second time-varying magnetic field component comprises operatively coupling either said first time-varying signal source or at least one second time-varying signal source to at least one second coil, and the operation of detecting said change in said magnetic condition of said vehicle comprises detecting a complex impedance of at least one of said first coil and said at least one second coil.

11. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, wherein the operation of generating said first time-varying magnetic field component comprises operatively coupling a first time-varying signal source to a first coil, the operation of generating said at least one second time-varying magnetic field component comprises operatively coupling either said first time-varying signal source or at least one second time-varying signal source to at least one second coil, and the operation of detecting said change in said magnetic condition of said vehicle comprises sampling in-phase and quadrature-phase components of at least one signal from at least one of said first coil and said at least one second coil.

12. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, wherein the operation of generating said first time-varying magnetic field component comprises operatively coupling a first time-varying signal source to a first coil, the operation of generating said at least one second time-varying magnetic field component comprises operatively coupling either said first time-varying signal source or at least one second time-varying signal source to at least one second coil, and the operation of detecting said change in said magnetic condition of said vehicle is responsive to at least one in-phase component of at least one signal from at least one of said first coil and said at least one second coil.

13. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, further comprising shaping at least one of said first time-varying magnetic field component and said at least one second time-varying magnetic field component responsive to at least one magnetic-field influencing property of at least one of said first portion of said vehicle and said at least one second portion of said vehicle.

14. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, further comprising operatively associating at least one conductive element with at least one of said first portion of said vehicle and said at least one second portion of said vehicle in cooperation with at least one of said first time-varying magnetic field component and said at least one second time-varying magnetic field component.

15. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, wherein said first portion of said vehicle and said at least one second portion of said vehicle comprise a body portion of said vehicle, and the operation of detecting said change in said magnetic condition of said vehicle provides for detecting a deformation of said body portion of said vehicle.

16. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 15, wherein said body portion of said vehicle comprises either a door, a quarter-panel, a hood, a roof, a trunk, or a bumper of said vehicle.

17. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 1, wherein said first portion of said vehicle and said at least one second portion of said vehicle comprise a bumper of said vehicle, and the operation of detecting said change in said magnetic condition of said vehicle provides for detecting a deformation of said bumper.

18. A method of detecting a change in a magnetic condition of a vehicle, comprising:

a. generating a first time-varying magnetic field component proximate to a first portion of the vehicle at a first location;

b. generating at least one second time-varying magnetic field component proximate to at least one second portion of said vehicle at at least one corresponding second location, wherein said at least one corresponding second location is separated from said first location, said first portion of said vehicle and said at least one second portion of said vehicle are at least partially conductive so that said first time-varying magnetic field component generates a corresponding first eddy current component in said first portion of said vehicle, and said at least one second time-varying magnetic field component generates a corresponding at least one second eddy current component in said at least one second portion of said vehicle;

c. operatively associating at least one conductive element with at least one of said first portion of said vehicle and said at least one second portion of said vehicle in cooperation with at least one of said first time-varying magnetic field component and said at least one second time-varying magnetic field component;

d. incorporating a pattern in said at least one conductive element so as to provide for controlling at least one associated eddy current therein; and

e. detecting a change in the magnetic condition of said vehicle responsive to a first signal responsive to said corresponding first eddy current component, and responsive to at least one second signal responsive to said corresponding at least one second eddy current component.

19. A method of detecting a change in a magnetic condition of a vehicle as recited in claim 18, further comprising either etching, forming or coating said pattern in or on at least one surface of said at least one conductive element.

20. A method of detecting a change in a magnetic condition of a vehicle, comprising:

a. generating a first time-varying magnetic field component proximate to a first portion of the vehicle at a first location;

b. generating at least one second time-varying magnetic field component proximate to at least one second portion of said vehicle at at least one corresponding second location, wherein said at least one corresponding second location is separated from said first location, said first portion of said vehicle and said at least one second portion of said vehicle are at least partially conductive so that said first time-varying magnetic field component generates a corresponding first eddy current component in said first portion of said vehicle, said at least one second time-varying magnetic field component generates a corresponding at least one second eddy current component in said at least one second portion of said vehicle, and said first portion of said vehicle and said at least one second portion of said vehicle comprise a door beam of a door of said vehicle; and

c. detecting a change in the magnetic condition of said vehicle responsive to a first signal responsive to said corresponding first eddy current component, and responsive to at least one second signal responsive to said corresponding at least one second eddy current component, wherein the operation of detecting said change in said magnetic condition of said vehicle provides for detecting a deformation of said door beam.