Method for establishing the occupation of a vehicle seat

• US 7,567,184 B2
• Filed: 10/15/2004
• Issued: 07/28/2009
• Est. Priority Date: 04/19/2002
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Betz, Volkmar, Stifter, Thomas
• Primary Examiner(s): Goins; Davetta W
• Assistant Examiner(s): Walk; Samuel J
• Application Number:
  US10/964,809
• Publication Number:
  US 20080204211A1
• Time in Patent Office: 1,747 Days
• Field of Search: 340/667
• US Class Current: 340/667
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means

Abstract

The invention relates to a method for differentiating between people and other objects on vehicle seats, by recording and evaluating the pressure distribution caused on the seat by said people and objects, the mean deviation of the signal at a certain position in relation to the mean signal of the adjacent region enabling the differentiation between people and other objects to be made. The invention is advantageous in that only few criteria are required and the criteria are not bound to any specific sensor structures (metrical, discrete etc.). Furthermore, where required, the individual criteria need only be combined in a simple manner.

Claims

1. A method for differentiating between persons and objects on a vehicle seat, the method comprising the acts of:

sensing a pressure distribution occurring on the vehicle seat; and

evaluating the pressure distribution to differentiate between a person and an object on the vehicle seat in accordance with a mean deviation of a signal at one position from a mean signal neighboring said one position.

2. A method according to claim 1, wherein the act of evaluating further comprises the acts of:

determining a mean deviation of the signal at several sensor positions from pertaining mean signals of the neighborhoods of said several sensor positions, and deriving a result value therefrom which differentiates between the person and the object.

3. The method according to claim 2, wherein at least one of the signals is subjected to a mathematical function before averaging.

4. The method according to claim 2, wherein a mathematical function is used on the signals after an averaging.

5. The method according to claim 1, wherein at least one of the signals is subjected to a mathematical function before averaging.

6. The method according to claim 5, wherein the mathematical function is one which either monotonically rises or falls.

7. The method according to claim 1, wherein a mathematical function is used on the signals after an averaging.

8. The method according to claim 7, wherein the mathematical function is one which either monotonically rises or falls.

9. The method according to claim 1, wherein the evaluating act occurs only in one partial area of the pressure distribution.

10. The method according to claim 1, wherein the act of evaluating is subjected to a mathematical time-dependent function.

11. The method according to claim 10, wherein the mathematical time-dependent function is a time averaging.

12. The method according to claim 1, wherein an area in which the pressure distribution is determined is a sensor mat having a number of pressure sensors.

13. The method according to claim 1, wherein pressure patterns are not evaluated as a person in a case in which a total intensity of the pressure distribution is below a defined threshold.

14. The method according to claim 1, wherein neighboring points are part of a common cohesive area.

15. A method for differentiating between persons and objects on a vehicle seat, the method comprising the acts of:

sensing a pressure distribution occurring on the seat;

evaluating the pressure distribution by dividing its area into partial areas, wherein certain constellations of active to inactive areas are evaluated as a person, an active area being one in which a cumulative signal is above a defined threshold.

16. The method according to claim 15, wherein the partial areas are neighboring.

17. The method according to claim 16, wherein a combination of the partial areas represents a total area.

18. The method according to claim 15, wherein the partial areas do not mutually overlap.

19. The method according to claim 18, wherein a combination of the partial areas represents a total area.

20. The method according to claim 15, wherein a combination of the partial areas represents a total area.

21. The method according to claim 15, wherein at least one sensor signal is subjected to a mathematical function before the cumulative signal is formed.

22. The method according to claim 21, wherein the mathematical function is one which either monotonically rises or falls.

23. The method according to claim 15, wherein before comparing the cumulative signal with the defined threshold, the cumulative signal is subjected to a mathematical function.

24. The method according to claim 23, wherein the mathematical function is one which either monotonically rises or falls.

25. The method according to claim 15, wherein the evaluating act occurs only in one partial area of the pressure distribution.

26. The method according to claim 15, wherein the act of evaluating is subjected to a mathematical time-dependent function.

27. The method according to claim 26, wherein the mathematical time-dependent function is a time averaging.

28. The method according to claim 15, wherein an area in which the pressure distribution is determined is a sensor mat having a number of pressure sensors.

29. The method according to claim 28, wherein the sensor mat comprises at least three pressure sensors.

30. The method according to claim 15, wherein pressure patterns are not evaluated as a person in a case in which a total intensity of the pressure distribution is below a defined threshold.

31. The method according to claim 15, wherein neighboring points are part of a common cohesive area.

32. The method according to claim 31, wherein the common cohesive area is defined such that two arbitrary points of the area are connectable by a connection path extending completely within the area.

33. A method for differentiating between persons and objects on a vehicle seat, the method comprising the acts of:

sensing a pressure distribution occurring on the vehicle seat;

evaluating the pressure distribution by forming a cumulative signal in a partial area of a total area in which the pressure distribution exists, and deriving a result value from the cumulative signal and a defined threshold, the result value differentiating between a person and an object being on the vehicle seat.

34. The method according to claim 33, wherein the partial area includes a central area, the central area being an area which contains no parts of an edge.

35. The method according to claim 34, wherein the act of logically linking is performed using an OR operation.

36. The method according to claim 35, wherein before performing the logically linking, at least one of the evaluating acts is negated.

37. The method according to claim 33, wherein the evaluating act occurs only in one partial area of the pressure distribution.

38. The method according to claim 33, wherein the act of evaluating is subjected to a mathematical time-dependent function.

39. The method according to claim 38, wherein the mathematical time-dependent function is a time averaging.

40. The method according to claim 33, wherein an area in which the pressure distribution is determined is a sensor mat having a number of pressure sensors.

41. The method according to claim 33, wherein pressure patterns are not evaluated as a person in a case in which a total intensity of the pressure distribution is below a defined threshold.

42. The method according to claim 33, wherein neighboring points are part of a common cohesive area.

43. A method for differentiating between persons and objects on a vehicle seat, the method comprising the acts of:

sensing a pressure distribution occurring on the vehicle seat caused by one of a person and an object; and

performing an evaluation by one or more of the following acts;

a) evaluating the pressure distribution to differentiate between a person and an object on the vehicle seat in accordance with a mean deviation of a signal at one position from a mean signal neighboring said one position;

b) evaluating the pressure distribution by dividing its area into partial areas, wherein certain constellations of active to inactive areas are evaluated as a person, an active area being one in which a cumulative signal is above a defined threshold;

c) evaluating the pressure distribution by forming a cumulative signal in a partial area of a total area in which the pressure distribution exists, and deriving a result value from the cumulative signal and a defined threshold, the result value differentiating between a person and an object being on the vehicle seat; and

logically linking the results of differentiating between the person and another object in accordance with the above evaluating acts.

44. The method according to claim 43, wherein the act of logically linking is performed using an AND operation.

45. The method according to claim 44, wherein before performing the logically linking, at least one of the evaluating acts is negated.

46. The method according to claim 43, wherein several logical operations are combinable with one another in a mathematical bracketing manner.