Vehicle occupant weight classification system

• US 7,464,960 B2
• Filed: 06/30/2004
• Issued: 12/16/2008
• Est. Priority Date: 07/12/2000
• Status: Expired due to Fees

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive Systems US Incorporated (Continental AG)
• Inventors: Winkler, Gerd, Schicker, Gerald, Knueppel, Andreas
• Primary Examiner(s): Silbermann; Joanne
• Assistant Examiner(s): Stabley; Michael R
• Application Number:
  US10/881,371
• Publication Number:
  US 20040232674A1
• Time in Patent Office: 1,630 Days
• Field of Search: 280/735, 180/273, 701/45, 340/436, 340/438, 340/667
• US Class Current: 280/735
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: G06V 40/10 Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
• CPC Class Codes: Y10T 74/18088 Rack and pinion type
• CPC Class Codes: Y10T 74/1967 Rack and pinion

Abstract

A vehicle occupant classification system categorizes vehicle occupants into various classes such as adult, child, infant, etc. to provide variable control for a vehicle restraint system such as an airbag. The classification system utilizes sensors that are installed in various locations in the vehicle. The sensors are used to generate a three-dimensional profile for the vehicle occupant. Various factors can affect the accuracy of this three-dimensional profile. Fuzzy logic is used to reduce some of the inaccuracies by providing multiple decision levels for various stages of the classification. Inaccuracies are also caused by sensors shifting within the system from their original position. This condition creates offset and the system evaluates this offset and generates a correction factor to provide a more accurate three-dimensional profile. Electrically erasable programmable read-only memory is used to reduce complications and inaccuracies associated with seat occupant weight sensors that have mounting configurations that vary depending upon the vehicle.

Claims

1. A method for determining vehicle occupant characteristics to classify vehicle occupants comprising the steps of:

(a) establishing a first position for an occupant sensor or a seat occupant;

(b) generating a plurality of occupant signals from the occupant sensor, generating a three-dimensional profile based on the plurality of occupant signals, and comparing the three-dimensional profile to an information factor;

(c) determining if there is a difference between the three-dimensional profile and the information factor; and

(d) generating a correction factor to correct for the difference if the three-dimensional profile varies from the information factor by a pre-determined amount.

2. The method according to claim 1 wherein step (a) further includes defining an initial occupant position by positioning an occupant on a seat, generating a corresponding initial occupant input value to generate an initial three-dimensional profile, and classifying the occupant based on the initial three-dimensional profile.

3. The method according to claim 2 including monitoring occupant position with the occupant sensor, identifying new sensor output values from the occupant sensor, generating a new three-dimensional profile based on the new sensor output values, and comparing the information factor to the new three-dimensional profile and applying the correction factor to generate a corrected three-dimensional profile to adjust occupant classification when the new-three-dimensional profile varies from the information factor by the pre-determined amount.

4. The method according to claim 3 wherein determining the difference as set forth in step (c) further includes determining the difference between the information factor and any new three-dimensional profiles generated in response to sensor output changes from the occupant sensor.

5. The method according to claim 4 including the step of installing a plurality of occupant sensors within a vehicle, generating the plurality of occupant signals with the plurality of occupant sensors to provide a plurality of occupant characteristic values defining one occupant position, generating new occupant characteristic values in response to new output data from the plurality of occupant sensors to define a new occupant position, generating the correction factor for each three-dimensional profile if the three-dimensional profile varies from the information factor by the pre-determined amount to define the corrected three-dimensional profile.

6. The method according to claim 1 wherein step (a) further includes determining a plurality of occupant characteristics based on the plurality of occupant signals to define an initial occupant position;

wherein step (b) further includes continuing to monitor the plurality of occupant signals to identify new sensor values, and generating a new three-dimensional profile for each new sensor value;

wherein step (c) further includes determining the difference based on a comparison of each three-dimensional profile to the information factor; and

wherein step (d) further includes applying the correction factor to generate a corrected three-dimensional occupant profile when each three-dimensional profile varies from the information factor by the pre-determined amount, and classifying the seat occupant based on the corrected three-dimensional occupant profile.

7. The method according to claim 1 including the steps of mounting a plurality of occupant sensors within a vehicle to generate the plurality of occupant signals, generating at least one initial occupant sensor value with the first position, being defined as an initial sensor position arrangement based on the occupant sensor value, generating the information factor based on the initial occupant sensor value, generating the three-dimensional occupant profile based on the plurality of occupant signals, comparing the information factor to the three-dimensional occupant profile, identifying variance when a current occupant sensor value varies from the initial occupant sensor value, defining the second position as a shifted sensor position arrangement once variance is identified, determining an amount of variance between the initial and shifted sensor position arrangements, applying the correction factor to the three-dimensional occupant profile to generate a corrected three-dimensional occupant profile, and classifying the seat occupant based on the corrected three-dimensional occupant profile.

8. A method for determining vehicle occupant characteristics to classify vehicle occupants comprising the steps of:

(a) establishing at least one initial occupant sensor value;

(b) comparing a subsequently measured occupant sensor value to the initial occupant sensor value to define a current occupant sensor value;

(c) identifying offset when the current occupant sensor value vanes from the initial occupant sensor value;

(d) automatically adjusting subsequently measured occupant sensor values to correct for the offset.

9. The method according to claim 8 further including the step of determining a degree of sensor position variance in response to detection of offset and generating a correction factor to correct subsequently measured occupant sensor values based on the degree of sensor position variance.

10. The method according to claim 9 including the step of installing a plurality of occupant sensors within a vehicle to define an initial occupant sensor position and wherein over a period of time at least one of the occupant sensors moves from an initial installed position to a shifted occupant sensor position with the offset being created by the shifted occupant sensor position.

11. The method according to claim 10 including the step of measuring a plurality of occupant characteristics with the occupant sensors to generate a plurality of occupant sensor values, and automatically adjusting the occupant sensor values by the correction factor.

12. The method according to claim 8 including the steps of generating an information factor based on the initial occupant sensor value, generating a three-dimensional occupant profile based on a plurality of occupant measurement signals, comparing the information factor to the three-dimensional occupant profile, generating a correction factor when the current occupant sensor value varies from the initial occupant sensor value, automatically applying the correction factor to the three-dimensional occupant profile to generate a corrected three-dimensional occupant profile, and classifying vehicle occupants based on the corrected three-dimensional occupant profile.

13. A system for determining vehicle occupant characteristics to classify vehicle occupants including:

a plurality of occupant sensors mounted within a vehicle to generate a plurality of occupant characteristic values in response to an occupant being present within the vehicle; and

a central processing unit for receiving said occupant characteristic values, establishing at least one initial occupant sensor value, comparing a subsequently measured occupant sensor value to said initial occupant sensor value to define a current occupant sensor value, identifying offset when said current occupant sensor value varies from said initial occupant sensor value, and automatically adjusting subsequently measured occupant sensor values to correct for the offset.

14. The system according to claim 13 wherein said central processing unit determines a degree of sensor or occupant position variance in response to detection of system offset and generates a correction factor to correct the at least one initial occupant characteristic value based on the degree of sensor or occupant position variance.

15. The system according to claim 14 wherein the plurality of occupant sensors are installed in an initial occupant sensor position and over a period of time at least one of the occupant sensors moves from an initial installed position to a shifted occupant sensor position with the system offset being created by the shifted occupant sensor position.

16. The system according to claim 14 wherein all occupant characteristic values are automatically adjusted by the correction factor.

17. The system according to claim 13 wherein said central processing unit generates an information factor based on said initial occupant sensor value, generates a three-dimensional occupant profile based on a plurality of occupant measurement signals, compares the information factor to the three-dimensional occupant profile, and generates a correction factor when said current occupant sensor value varies from said initial occupant sensor value, said central processing unit automatically applying said correction factor to said three-dimensional occupant profile to generate a corrected three-dimensional occupant profile and classifying vehicle occupants based on the corrected three-dimensional occupant profile.

18. A system for classifying vehicle occupants including:

a plurality of sensors mounted within a vehicle for monitoring and determining a position of an occupant within the vehicle wherein said plurality of sensors generates a first plurality of occupant measurement signals in response to the occupant being present within the vehicle;

a central processing unit for receiving said first plurality of occupant measurement signals and generating a first three-dimensional profile based on said first plurality of occupant measurement signals,

a memory unit for storing an information factor for comparison to said first three-dimensional profile to determine a difference between said first three-dimensional profile and said information factor wherein said central processing unit generates a correction factor if said first three-dimensional profile varies from said information factor by a pre-determined amount resulting in generation of a corrected three-dimensional profile and wherein said central processing unit classifies the occupant based on either the first or corrected three-dimensional profile.

19. The system according to claim 18, wherein said plurality of sensors generates a second plurality of occupant measurement signals in response to the occupant changing position within the vehicle and generates a subsequent plurality of occupant measurement signals each time the occupant changes position;

said central processing unit receiving said second plurality of occupant measurement signals and said subsequent plurality of occupant measurement signals and generating a second three-dimensional profile based on said second plurality of occupant measurement signals and generating at least one subsequent three-dimensional profile based on said subsequent plurality of occupant measurement signals; and

wherein said memory unit compares said second three-dimensional profile and any of said subsequent three-dimensional profiles to said information factor to determine a difference between said second three-dimensional profile and said information factor and a difference between any of said subsequent three-dimensional profiles and said information factor wherein said central processing unit generates a correction factor if said second three-dimensional profile or any subsequent three-dimensional profile varies from said information factor by the pre-determined amount resulting in generation of the corrected three-dimensional profile.

20. The system according to claim 19 wherein said plurality of sensors includes a plurality of weight sensors and a plurality of occupant sensors.