Apparatus for protecting occupant in vehicle

• US 20030081814A1
• Filed: 09/12/2002
• Published: 05/01/2003
• Est. Priority Date: 10/30/2001
• Status: Active Grant

• Current Assignee: DENSO Corporation, Nippon Soken, Inc.
• Original Assignee: DENSO Corporation, Nippon Soken, Inc.
• Inventors: Sato, Hironori, Imanishi, Masayuki, Takagi, Akira, Goto, Tomoyuki
• Granted Patent: US 7,139,410 B2
• Time in Patent Office: Days
• US Class Current: 382/104
• CPC Class Codes: B60R 21/0152 using strain gauges
• CPC Class Codes: B60R 21/01538 for image processing, e.g. cameras or sensor arrays
• CPC Class Codes: B60R 21/01542 detecting passenger motion
• CPC Class Codes: B60R 21/01552 detecting position of specific human body parts, e.g. face, eyes or hands
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80

Abstract

An apparatus for protecting an occupant in a vehicle includes a pair of image sensors for taking images of an area on a seat in the vehicle. Transverse-direction shifts between corresponding portions of the images are calculated. Longitudinal-direction positions of objects whose images are in the portions of the images taken by the image sensors are measured in response to the calculated transverse-direction shifts. A longitudinal-direction position of an occupant on the seat is decided in response to the measured longitudinal-direction positions of the objects. Occupant protecting operation at a time of occurrence of a collision of the vehicle is changed in response to the decided longitudinal-direction position of the occupant. From the measured longitudinal-direction positions of the objects, one corresponding to a highest position with respect to the vehicle and being in front of the seat is selected as a longitudinal-direction position of a head of the occupant.

Claims

1. An apparatus for protecting an occupant in a vehicle having a seat, comprising:

a pair of area image sensors spaced at a prescribed interval in a transverse direction of the vehicle and located in front of the seat for taking images of an area on the seat respectively;

an occupant information calculating portion for calculating transverse-direction shifts between corresponding portions of the images taken by the area image sensors, for measuring longitudinal-direction positions of objects whose images are in the portions of the images taken by the area image sensors in response to the calculated transverse-direction shifts according to triangulation, and for deciding a longitudinal-direction position of an occupant on the seat in response to the measured longitudinal-direction positions of the objects; and

an occupant protecting portion for changing occupant protecting operation at a time of occurrence of a collision of the vehicle in response to the longitudinal-direction position of the occupant which is decided by the occupant information calculating portion;

wherein the occupant information calculating portion comprises means for selecting, from the measured longitudinal-direction positions of the objects, one corresponding to a highest position with respect to the vehicle and being in front of the seat as a longitudinal-direction position of a head of the occupant.

2. An apparatus as recited in claim 1, wherein the occupant information calculating portion comprises means for dividing the images taken by the area image sensors into blocks, for calculating transverse-direction shifts between corresponding blocks of the images taken by the area image sensors, for measuring longitudinal-direction positions of objects whose images are in the blocks of the images taken by the area image sensors in response to the calculated transverse-direction shifts according to triangulation, and for selecting, from the measured longitudinal-direction positions of the objects, one corresponding to a highest position with respect to the vehicle and being in front of the seat as the longitudinal-direction position of the head of the occupant.

3. An apparatus as recited in claim 2, wherein the occupant information calculating portion comprises means for calculating a cumulative difference between corresponding blocks, in each pair, of the images taken by the area image sensors while shifting one of the corresponding blocks relative to the other on a unit by unit basis, means for detecting when the calculated cumulative difference minimizes, means for calculating a transverse-direction shift between the corresponding blocks which occurs when the calculated cumulative difference minimizes, and for measuring a longitudinal-direction position of an object whose images are in the corresponding blocks in response to the calculated transverse-direction shift according to triangulation.

4. An apparatus as recited in claim 3, wherein the occupant information calculating portion comprises means for calculating a cumulative difference between prescribed corresponding blocks in a pair during a time interval after the area image sensors output signals representing the prescribed corresponding blocks and before the area image sensors complete outputting signals representing all the blocks.

5. An apparatus as recited in claim 2, wherein the occupant information calculating portion comprises means for sequentially implements the measurements of the longitudinal-direction positions of objects whose images are in the blocks of the images taken by the area image sensors in an order from a highest-position block toward a lowest-position block, means for deciding whether or not the measured longitudinal-direction position of each object is in front of the seat, and means for, when it is decided that the measured longitudinal-direction position of the object is in front of the seat, deciding the measured longitudinal-direction position of the object to be the longitudinal-direction position of the head of the occupant.

6. An apparatus for protecting an occupant in a vehicle having a seat, comprising:

a distance measurement device located in front of the seat for measuring a distance to an occupant on the seat;

an occupant information calculating portion for calculating a longitudinal-direction position of the occupant from the distance measured by the distance measurement device; and

an occupant protecting portion for changing occupant protecting operation at a time of occurrence of a collision of the vehicle in response to the longitudinal-direction position of the occupant which is calculated by the occupant information calculating portion;

wherein the distance measurement device includes a plurality of ultrasonic distance measurement sensors for measuring distances to objects in blocks composing a measured area, and wherein the occupant information calculating portion comprises means for selecting, from the distances measured by the ultrasonic distance measurement sensors, one corresponding to a highest position with respect to the vehicle and being in front of the seat as an indication of a longitudinal-direction position of a head of the occupant.