Vehicle occupant position sensor utilizing image focus attributes

• US 20020135165A1
• Filed: 03/26/2001
• Published: 09/26/2002
• Est. Priority Date: 03/26/2001
• Status: Active Grant

• Current Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Wallace, Jon K., Khairallah, Farid, Zayan, Nicholas M., Cooper, Stephen R.W.
• Granted Patent: US 6,578,869 B2
• Time in Patent Office: Days
• US Class Current: 280/735
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60R 21/01538 for image processing, e.g. cameras or sensor arrays
• CPC Class Codes: G06T 7/73 using feature-based methods

Abstract

A vehicle occupant sensor apparatus (34) has an imager (36) that gathers an image of an occupant (12). The image has focus attributes. A focal plane associated with the imager (36) is at a distance from the imager. A 2D high-pass filter (42), a multiple frame temporal filter (46), and a position determination component (52) operate to determine position of the occupant (12) relative to the focal plane (38) via use of the focus attributes.

Claims

1. A vehicle occupant sensor apparatus comprising:

means for gathering an image of an occupant, the image having focus attributes, a focal plane associated with said means for gathering being at a distance from said means for gathering; and

means for determining position of the occupant relative to the focal plane utilizing the focus attributes.

2. An apparatus as set forth in claim 1, wherein said means for determining position comprises means for determining whether an imaged surface the occupant is forward or rearward of the focal plane.

3. An apparatus as set forth in claim 1, wherein said means for determining comprises means for determining position of the occupant relative to the focal plane utilizing image sharpness.

4. An apparatus as set forth in claim 3, wherein said means for gathering an image comprises means for providing image indicative signals, said means for determining comprises means for filtering the image indicative signals to pass high frequency components, means for determining high frequency content and means for determining position of the occupant relative to the focal plane utilizing the determined high frequency content.

5. An apparatus as set forth in claim 1, wherein said means for determining comprises means for determining position of the occupant relative to the focal plane utilizing image size.

6. A vehicle occupant sensor apparatus comprising:

an imager that collects an image of an occupant and that outputs a signal indicative of the collected image, the image having focus attributes, a focal plane associated with said imager being at a distance from said imager;

a two-dimensional high pass filter operatively connected to the imager to provide a signal indicative of high frequency content of the imager signal;

a multiple frame temporal filter operatively connected to the imager to provide a signal indicative of image size conveyed by the imager signal; and

a position determination component operatively connected to said two-dimensional high pass filter and said multiple frame temporal filter to determine position of the occupant relative to the focal plane utilizing the signal indicative of high frequency content of the imager signal the signal indicative of image size conveyed by the imager signal.

7. A method of sensing a vehicle occupant comprising:

gathering an image of an occupant, the image having focus attributes, a focal plane being at a distance from a location of image gathering; and

determining position of the occupant relative to the focal plane utilizing the focus attributes.

8. A method as set forth in claim 7, wherein said step of determining position comprises determining whether an imaged surface the occupant is forward or rearward of the focal plane.

9. A method as set forth in claim 7, wherein said step of determining comprises determining position of the occupant relative to the focal plane utilizing image sharpness.

10. A method as set forth in claim 9, wherein said step of gathering an image comprises providing image indicative signals, said step of determining comprises filtering the image indicative signals to pass high frequency components, determining high frequency content and determining position of the occupant relative to the focal plane utilizing the determined high frequency content.

11. A method as set forth in claim 7, wherein said step of determining comprises determining position of the occupant relative to the focal plane utilizing image size.