Method of determining an equivalent value for a failed sensor in a vehicle seat having an occupancy sensing system

• US 7,053,759 B2
• Filed: 10/27/2004
• Issued: 05/30/2006
• Est. Priority Date: 12/30/2003
• Status: Expired due to Fees

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: Nathan, John F., Young, Oliver J., Kennedy, Karl R., Ricard, Christopher T., Malayappan, Shridhar
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US10/974,624
• Publication Number:
  US 20050140358A1
• Time in Patent Office: 580 Days
• Field of Search: 340/438, 200/85.A
• US Class Current: 340/438
• 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 2021/01184 Fault detection or diagnostic circuits in power circuits B60R2021/01129
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means

Abstract

A method of determining an equivalent output value for a failed sensor in a vehicle seat having an occupancy sensing system. The method includes the steps of sensing the output of each sensor in an array of sensors that detect a physical presence in the seat. If the output of the sensor falls below a predetermined value, exceeds a predetermined value, or remains fixed the sensor is classified as inoperative. The method then calculates an equivalent sensor output value for any sensor classified as inoperative and applies the sensor array output values for each operable sensor in the array and the calculated equivalent output value for any inoperative sensor to a neural net. Then, the applied sensor output values are recognizing as falling within one of a group of predetermined classification patterns that represent a physical presence in the seat defined by size, weight, and physical orientation.

Claims

1. A method of determining an equivalent output value for a failed sensor having an output in a vehicle seat having a occupancy sensing system, said method including the steps of:

sensing the output of each sensor in an array of sensors that detect a physical presence in the seat;

classifying a sensor as inoperative when the output of the sensor is characterized as one from a group including a sensor output that falls below a predetermined value, exceeds a predetermined value, and remains fixed;

calculating an equivalent sensor output value for any sensor classified as inoperative;

applying the sensor array output values for each operable sensor in the array and the calculated equivalent output value for any inoperative sensor to a neural net; and

recognizing the applied sensor output values as one of a group of predetermined classification patterns that represent a physical presence in the seat defined by size, weight, and physical orientation.

2. A method as set forth in claim 1, wherein the step of calculating an equivalent sensor output value for any sensor classified as inoperative further includes the steps of:

determining which sensors are neighboring to the inoperative sensor within the array;

sensing the output of each neighboring sensor;

retrieving a predetermined weight factor value for each neighboring sensor that represents the operative correlation between the inoperative sensor and the particular neighboring sensor from a stored database; and

performing a mathematical summation of the output of each neighboring sensor multiplied by the predetermined weight factor value for that particular neighboring sensor to yield the equivalent sensor output value for the inoperative sensor.

3. A method as set forth in claim 1, wherein the step of recognizing the applied sensor output values as one of a group of predetermined classification patterns further includes the step of continuously reinitiating the method steps to continuously recognize the classification pattern.

4. A method as set forth in claim 3, wherein the step of continuously reinitiating the method steps further includes the steps of:

determining if more than two sensors have been classified as inoperative;

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.

5. A method as set forth in claim 1, wherein said step of classifying a sensor as inoperative when the output of the sensor falls below a predetermined value further includes the steps of:

determining if the sensor is one that falls into a predetermined group of critical sensors such that an equivalent sensor output will not be calculated;

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.

6. A method as set forth in claim 1, wherein said step of classifying a sensor as inoperative when the output of the sensor exceeds a predetermined value further includes the steps of:

determining if the sensor is one that falls into a predetermined group of critical sensors such that an equivalent sensor output will not be calculated;

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.

7. A method as set forth in claim 1, wherein said step of classifying a sensor as inoperative when the output of the sensor remains fixed further includes the steps of:

determining if the sensor is one that falls into a predetermined group of critical sensors such that an equivalent sensor output will not be calculated;

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.

8. A method of determining an equivalent output value for a failed sensor having an output in a vehicle seat having a occupancy sensing system, said method including the steps of:

sensing the output of each sensor in an array of sensors that detect a physical presence in the seat;

classifying a sensor as inoperative when the output of the sensor is characterized as one from a group including a sensor output that falls below a predetermined value, exceeds a predetermined value, and remains fixed;

when a sensor has been classified as inoperative, determining if the inoperative sensor is one that falls into a predetermined critical group of sensors such that an equivalent sensor output will not be calculated;

determining which sensors are neighboring to the inoperative sensor within the array when a sensor is classified as inoperative and is not in the predetermined critical group;

sensing the output of each neighboring sensor;

retrieving a predetermined weight factor value for each neighboring sensor that represents the operative correlation between the inoperative sensor and the particular neighboring sensor from a stored database;

performing a mathematical summation of the output of each neighboring sensor multiplied by the predetermined weight factor value for that particular neighboring sensor to yield the equivalent sensor output value for the inoperative sensor;

applying the output values for each operable sensor in the array and the calculated equivalent output value for any inoperative sensor to a neural net; and

recognizing the output values as one of a group of predetermined classification patterns that represent a physical presence in the seat defined by size, weight, and physical orientation.

9. A method as set forth in claim 8, wherein the step of recognizing the sensor array output further includes the step of continuously reinitiating the method steps to continuously recognize the classification pattern.

10. A method as set forth in claim 9, wherein the step of continuously reinitiating the method steps further includes the steps of:

determining if more than two sensors have been classified as inoperative;

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.

11. A method as set forth in claim 8, wherein said step of classifying a sensor as inoperative when the output of the sensor falls below a predetermined value further includes the steps of:

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.

12. A method as set forth in claim 8, wherein said step of classifying a sensor as inoperative when the output of the sensor exceeds a predetermined value further includes the steps of:

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.

13. A method as set forth in claim 8, wherein said step of classifying a sensor as inoperative when the output of the sensor remains fixed further includes the steps of:

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.

14. A method of determining an equivalent output value for a failed sensor having an output in a vehicle seat having a occupancy sensing system, said method including the steps of:

sensing the output of each sensor in an array of sensors that detect a physical presence in the seat;

classifying a sensor as inoperative when the output of the sensor is characterized as one from a group including a sensor output that falls below a predetermined value, exceeds a predetermined value, and remains fixed;

determining which sensors are neighboring to the inoperative sensor within the array when a sensor is classified as inoperative;

sensing the output of each neighboring sensor;

retrieving a predetermined weight factor value for each neighboring sensor that represents the operative correlation between the inoperative sensor and the particular neighboring sensor from a stored database;

determining the equivalent sensor output value for the inoperative sensor as an estimate based on the output of each neighboring sensor and the predetermined weight factor value for that particular neighboring sensor using an equation defined as;

15. A method as set forth in claim 14, wherein said step of classifying a sensor as inoperative when the output of the sensor falls below a predetermined value further includes the steps of:

determining if the sensor is one that falls into a predetermined group of critical sensors such that an equivalent sensor output will not be calculated;

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.

16. A method as set forth in claim 14, wherein said step of classifying a sensor as inoperative when the output of the sensor exceeds a predetermined value further includes the steps of:

determining if the sensor is one that falls into a predetermined group of critical sensors such that an equivalent sensor output will not be calculated;

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.

17. A method as set forth in claim 14, wherein said step of classifying a sensor as inoperative when the output of the sensor remains fixed further includes the steps of:

determining if the sensor is one that falls into a predetermined group of critical sensors such that an equivalent sensor output will not be calculated;

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.

18. A method as set forth in claim 14, wherein the step of continuously reinitiating the method steps further includes the steps of:

determining if more than two sensors have been classified as inoperative;

classifying the occupancy sensing system for the particular vehicle seat as inoperative when more than two sensors have been classified as inoperative; and

activating an operator warning device indicating the inoperative status of the occupancy sensing system for the particular vehicle seat.