Apparatus and method of compensating a seat offset for a load applied to the seat

• US 7,676,339 B2
• Filed: 09/28/2005
• Issued: 03/09/2010
• Est. Priority Date: 10/12/2004
• Status: Expired due to Fees

• Current Assignee: Robert Bosch Corporation (Robert Bosch GmbH), Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Fleet, Chad Van
• Primary Examiner(s): Cosimano; Edward R
• Assistant Examiner(s): Le; Toan M
• Application Number:
  US11/237,235
• Publication Number:
  US 20060091658A1
• Time in Patent Office: 1,623 Days
• Field of Search: 702/101, 702/85, 702/87, 702/98, 702/102, 702/105, 702/127, 702/129, 702/138, 702/139, 702/173, 702/174, 702/179, 702182-184, 702/189, 702193-195, 280/734, 280/751, 280/730.1, 280/728.1, 280/735, 280/748, 280/802, 340/457.1, 340/501, 340/514, 340665-667, 701/45, 177/144, 177/202, 177/203, 738/620.45, 73/11.3, 738/620.41, 180/268, 180/271, 180/273, 180/289
• US Class Current: 702/101
• 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: B60N 2/0025 by using weight measurement
• CPC Class Codes: B60N 2/0031 mounted on the frame
• CPC Class Codes: B60N 2220/10 using a database
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means

Abstract

A method of compensating a measurement. The method includes determining a zero-point, determining a rate of change of the zero-point, and compensating the measurement based on the rate of change of the zero-point and/or the zero-point. In one embodiment, the compensated measurement is used to control a safety device in a vehicle.

Claims

1. A method of compensating a measurement and controlling a device, the method comprising:

determining a zero-point of a sensing system;

determining a measurement by subtracting the zero-point from a sensed weight;

determining a rate of change of the zero-point from a delta function, wherein the delta function defines the rate of change of the zero-point as a function of the difference between the sensed weight and the zero-point;

updating the measurement at regular intervals based on the zero-point and the rate of change of the zero-point; and

using the updated measurement to control a device.

2. The method of claim 1, wherein the zero-point comprises a first zero-point, and wherein updating the measurement includes:

determining a zero-point change from the rate of the change of the zero-point;

determining an updated zero-point from the first zero-point and the zero-point change; and

adjusting the measurement with the updated zero-point.

3. The method of claim 2, further comprising replacing the first zero-point with the updated zero-point.

4. The method of claim 2, wherein the delta function defines a magnitude of the zero-point change as inversely related to the difference between the sensed weight and the zero-point.

5. The method of claim 2, wherein the delta function defines a magnitude of the zero-point change as a first value when the difference between the sensed weight and the zero-point is within a first range, and defines the magnitude of the zero-point change as a second value when the difference between the sensed weight and the zero-point is outside of the first range.

6. The method of claim 5, wherein the second value equals zero.

7. The method of claim 1, wherein determining the zero-point comprises retrieving the zero-point from a computer-readable medium.

8. The method of claim 1, further comprising sensing phenomena.

9. The method of claim 1, wherein determining a rate of change of the zero-point from a delta function includes retrieving the delta function from a computer-readable medium.

10. A method of compensating for a load applied to a seat and controlling a safety device, the method comprising:

retrieving a zero-point of the seat from a computer readable memory;

determining a weight of the load by subtracting the zero-point from a total sensed weight, wherein the total sensed weight is the weight of the seat when empty plus the weight of the load applied to the seat;

determining a rate of zero-point change from a delta function, wherein the delta function defines the rate of zero-point change as a function of a difference between the total sensed weight and the zero-point;

updating the zero-point of the seat at regular intervals based on the zero-point and the rate of the zero-point change;

updating the weight of the load based on the updated zero-point; and

using the updated weight of the load to control the safety device.

11. The method of claim 10, wherein updating the zero-point comprises:

determining a zero-point change from the rate of zero-point change;

comparing the total sensed weight with the zero point; and

adjusting the zero-point with the zero-point change if the total sensed weight differs from the zero-point.

12. The method of claim 10, wherein the zero-point comprises a first zero-point, the method further comprising replacing the first zero-point with the updated zero-point.

13. The method of claim 10, further comprising updating the zero-point of the seat at regular intervals based on the zero-point and the rate of the zero-point change when the seat is occupied and when the seat is unoccupied.

14. A system for compensating for a load applied to a seat, the system comprising:

a computer-readable medium configured to store a zero-point of the seat;

a sensor configured to sense a total weight, wherein the total weight is the weight of the seat when empty and the load applied to the seat;

a processor comprising a delta function module, wherein the delta function module is configured to determine a zero-point change at regular intervals as a function of the difference between the total weight and the zero-point; and

a compensating module configured to determine a weight of the load by compensating the total weight based on the zero-point and the zero-point change.

15. The system of claim 14, wherein the compensating module further comprises a first module configured to receive the zero-point change, and to update the zero-point with the zero-point change.

16. The system of claim 14, wherein the compensating module further comprises a second module configured to subtract the zero-point from the total weight.

17. The system of claim 14, wherein the processor is further configured to compare the total weight with the zero-point, and to adjust the zero-point when the total weight differs from the zero-point.

18. The system of claim 14, wherein the delta function module is further configured to determine a zero-point change that is inversely related to the difference between the total weight and the zero-point.

19. The system of claim 14, wherein the delta function module is further configured to set the zero-point change to equal a first value when the difference between the sensed weight and the zero-point is within a first range, and set the zero-point change to equal zero a second value when the difference between the sensed weight and the zero-point is outside of the first range.

20. The system of claim 19, wherein the second value equals zero.

21. The system of claim 14, wherein the processor is further configured to run the delta function module and the compensating module when the seat is occupied and when the seat is unoccupied.

22. A method of controlling a restraint device in a vehicle having a seat, the method comprising:

determining a weight applied to the seat of the vehicle by sensing a total weight and subtracting a zero-point from the total weight, wherein the total weight is the weight of the seat when empty plus the weight of the load applied to the seat;

using a delta function to determine a rate of zero-point change as a function of the difference between the total weight and the zero-point;

adjusting the zero-point at regular intervals based on the rate of zero-point change;

compensating the total weight with the undated zero-point; and

activating the restraint device after the total weight has been compensated.

23. The method of claim 22, wherein adjusting the zero-point comprises:

retrieving a zero-point;

determining an intermediate zero-point from the rate of zero-point change and the total weight;

comparing the total weight with the intermediate zero-point; and

updating the zero-point with the intermediate zero-point when the intermediate zero-point differs from the total weight.

24. The method of claim 22, wherein compensating the total weight comprises subtracting the zero-point from the total weight.

25. The method of claim 22, further comprising storing the updated zero-point.

26. A method of controlling a vehicle, the method comprising:

sensing a value of at least one phenomenon experienced by the vehicle;

using a delta function to determine a rate of zero-point change as a function of the difference between a zero-point and the sensed value;

repeatedly and automatically adjusting the zero-point based on the rate of zero-point change;

compensating the sensed value with the zero-point;

outputting the compensated sensed value; and

controlling the vehicle using the compensated value.

27. The method of claim 26, wherein adjusting a zero-point comprises:

retrieving a zero-point;

determining an intermediate zero-point from the rate of zero-point change and the sensed value;

comparing the sensed value with the intermediate zero-point; and

updating the zero-point with the intermediate zero-point when the intermediate zero-point differs from the sensed value.

28. The method of claim 26, wherein compensating the sensed value comprises subtracting the zero-point from the sensed value.

29. The method of claim 26, further comprising storing the adjusted zero-point.

30. A compensating system for use with a sensor adapted to sense a value of at least one phenomenon, the system comprising:

a computer-readable medium configured to store a zero-point of the sensor;

a processor comprising a delta function module, wherein the delta function module is configured to repeatedly and automatically determine a zero-point change as a function of the difference between the zero-point and the sensed value; and

a module configured to adjust the sensed value based on the zero-point and the zero-point change.

31. The system of claim 30, wherein the module further comprises a first module configured to receive the zero-point change, and to update the zero-point with the zero-point change.

32. The system of claim 30, wherein the module further comprises a second module configured to subtract the zero-point from the sensed value.

33. The system of claim 30, wherein the processor is further configured to compare the sensed value to the zero-point, and to adjust the zero-point when the sensed value differs from the zero-point.

34. The system of claim 30, further comprising a sensor adapted to sense the value.