Vehicle occupant proximity seat sensor

• US 6,693,440 B2
• Filed: 11/20/2001
• Issued: 02/17/2004
• Est. Priority Date: 09/29/2000
• Status: Expired due to Term

• Current Assignee: Appy Risk Technologies Limited (Trak Global Group Ltd.)
• Original Assignee: Intelligent Mechatronic Systems Inc. (Trak Global Group Ltd.)
• Inventors: Karray, Fakhreddine, Filippov, Vladimir, Basir, Otman Adam
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): He, Amy
• Application Number:
  US09/989,544
• Publication Number:
  US 20020180463A1
• Time in Patent Office: 819 Days
• Field of Search: 324/661, 324/662, 324/671, 280/731, 280/732, 280/735, 701/45, 701/46, 701/47, 340/552, 340/562, 340/567, 180/286, 703/10-- 1
• US Class Current: 324/662
• CPC Class Codes: B60R 21/01532 using electric or capacitive field sensors
• CPC Class Codes: B60R 21/01538 for image processing, e.g. cameras or sensor arrays

Abstract

A vehicle occupant proximity sensor includes a transmitting electrode in a vehicle seat and an array of receiving electrodes mounted in the vehicle seat. The sensor determines the capacitance at each of the receiving electrodes, which varies based upon the proximity of the occupant to each receiving electrode, thus producing an array of proximity information indicating in two dimensions the position of the occupant.

Claims

1. A method for determining whether to activate a vehicle occupant safety system for an occupant of a seat including the steps of:

a. Receiving an electromagnetic signal at a plurality of laterally-spaced points on a seating surface of the vehicle seat;

b. Determining a position of the occupant relative to the seat based upon said step a; and

c. Determining whether to activate the vehicle occupant safety system based upon said step b.

2. The method of claim 1 wherein said seat comprises a base and a back, said step a including the step of receiving the electromagnetic signal at the plurality of points in the base of the seat.

3. The method of claim 2 further includes the step of transmitting the electromagnetic signal from the base of the seat.

4. The method of claim 2 wherein said step a further includes the step of receiving the electromagnetic signal at the plurality of points in the back of the seat.

5. The method of claim 4 further includes the step of transmitting the electromagnetic signal from the back of the seat.

6. The method of claim 5 further including the step of:

d. determining the capacitance at a plurality of points adjacent the seat based upon said step a.; and

e. performing said step b based upon said step d.

7. The method of claim 1 wherein said step a. further includes the step of transmitting the electromagnetic signal from the seat.

8. The method of claim 1 wherein said step a. further includes the step of measuring capacitance based upon the electromagnetic signal received at the plurality of points.

9. The method of claim 8 wherein said step a. further includes the step of measuring capacitance at an array of the plurality of points.

10. The method of claim 9 wherein said step a. further includes the step of comparing the capacitance measured at each of the plurality of points with each other.

11. The method of claim 10 wherein said step a. further includes the step of:

d) monitoring a change in capacitance over time at the plurality of points; and

e) in said step c), determining whether to activate the vehicle occupant safety system based upon said step d).

12. The method of claim 1 wherein the plurality of points are arranged in at least two dimensions on the seating surface of the vehicle seat, wherein the seating surface is a seat base or a seat back.

13. The method of claim 1 wherein a first plurality of the plurality of points is laterally-spaced from a second plurality of the plurality of points.

14. The method of claim 1 further including the step of:

d. evaluating a position of the vehicle seat relative to the occupant safety system prior to said step c.; and

wherein the step of determining in said step c. is also based upon said step d.

15. The method of claim 14 wherein the position of the vehicle seat is determined from a seat track sensor.

27. The method of claim 1 further including the steps of:

d. Simultaneously transmitting the electromagnetic signal from a plurality of transmission points in the vehicle seat.

28. The method of claim 27 wherein the plurality of points at which the electromagnetic signal is received in said step a. is a plurality of reception points, and wherein the plurality of reception points are alternated with the plurality of transmission points.

29. The method of claim 28 wherein one of the plurality of transmission points and the plurality of reception points is laterally spaced relative to the other.

30. A The method of claim 29 wherein the one of the plurality of transmission points and the plurality of reception points is laterally spaced on both lateral sides of the other.

16. A vehicle passenger compartment proximity sensing system comprising:

A capacitive sensor array in a seat in a vehicle passenger compartment measuring capacitance at a plurality of points in the vehicle passenger compartment; and

A controller determining a position of an occupant relative to the seat based upon a comparison of the capacitance measured at the plurality of points with each other.

19. The system of claim 16 wherein the controller evaluates absolute values of the capacitance measured at each of the plurality of points to determine the position of the occupant.

17. The vehicle passenger compartment proximity sensing system of claim further comprising:

A first electrode generating an electromagnetic signal;

Said capacitive sensor array comprising a plurality of second electrodes mounted in the seat receiving the electromagnetic signal; and

the controller determining capacitance at each of the second electrodes to determine the position of the occupant relative to the seat.

18. The vehicle passenger compartment proximity sensing system of claim 17 wherein the first electrode is mounted in the seat in the vehicle passenger compartment.

20. A method for activating a vehicle occupant safety system including the steps of:

receiving an electromagnetic signal at each of a plurality of points in a seat in a vehicle passenger compartment having an occupant safety system;

measuring capacitance based upon the electromagnetic signal received at the plurality of points;

comparing the capacitance measured at each of the plurality of points with each other; and

determining a position of an occupant relative to the seat based upon said step c).

21. The method of claim 20 further including the step of:

Determining whether to activate the vehicle occupant safety system based upon said step d).

22. The method of claim 21 further including the step of transmitting the electromagnetic signal from the seat.

23. A vehicle passenger compartment proximity sensor system comprising:

a capacitive sensor array in a seat in a vehicle passenger compartment measuring capacitance at a plurality of laterally-spaced points in the vehicle passenger compartment, the capacitive sensor array including a receiving electrode array, the system further including a transmitting electrode array; and

a controller determining a position of an occupant relative to the seat based upon the capacitance measured at the plurality of points.

24. The system of claim 23 wherein the receiving electrode array and the transmitting electrode array are mounted in a seat back of the vehicle seat.

25. The system of claim 24 wherein each of the receiving electrode array and the transmitting electrode array comprises lateral halves, each lateral half of each array including a plurality of electrodes.

26. A vehicle passenger compartment proximity sensor system comprising:

a capacitive sensor array in a seat in a vehicle passenger compartment measuring capacitance at a plurality of points in the vehicle passenger compartment, the capacitive sensor array including a receiving electrode array, the system further including a transmitting electrode array, wherein each electrode in the receiving electrode array is positioned between two of the electrodes of the transmitting electrode array; and

a controller determining a position of an occupant relative to the seat based upon the capacitance measured at the plurality of points.

31. A vehicle passenger compartment proximity sensing system comprising:

a plurality of capacitive sensors in a seat in a vehicle passenger compartment measuring capacitance at a plurality of points on a seating surface of the seat, the capacitive sensors including a plurality of electrodes, at least one of which is laterally spaced from an other one of the plurality of electrodes; and

a controller determining a position of an occupant relative to the seat based upon the capacitance measured at the plurality of points.

32. The system of claim 31 wherein the plurality of electrodes includes a plurality of receiving electrodes in the seat.

33. The system of claim 32 wherein the plurality of electrodes includes a plurality of transmitting electrodes in the seat.

34. The system of claim 33 wherein the plurality of receiving electrodes is laterally spaced from the plurality of transmitting electrodes.

35. The system of claim 32 wherein the plurality of receiving electrodes includes a first plurality of receiving electrodes laterally spaced from a second plurality of receiving electrodes.

37. The system of claim 31 further including a seat track sensor determining a position of the seat, the controller determining the position of the occupant relative to a vehicle occupant safety system based the position of the seat and based upon the position of the occupant relative to the seat.

38. The system of claim 31 wherein the capacitive sensors include a first plurality of capacitive sensors in the seat laterally spaced from a second plurality of capacitive sensors in the seat.

36. The system of 31 wherein the seating surface is an upper surface of a seat base and a front surface of a seat back.

39. A method for determining whether to activate a vehicle occupant safety system for an occupant of a seat including the steps of:

a. receiving an electromagnetic signal at a plurality of laterally-spaced points in the vehicle seat;

b. determining a position of the occupant relative to the seat based upon said step a;

c. determining a position of the seat relative to the vehicle occupant safety system;

d. determining a position of the occupant relative to the occupant safety system based upon said steps b. and c.; and

e. determining whether to activate the occupant safety system based upon said step d.

40. The method of claim 39 wherein the plurality of points includes a first plurality of points laterally spaced from a second plurality of points.

41. The method of claim 39 wherein the plurality of points is a plurality of reception points and wherein said step a. further includes the step of transmitting the electromagnetic signal from a plurality of transmission points interspersed among the plurality of reception points.

42. The method of claim 41 wherein the plurality of transmission points are laterally and longitudinally interspersed among the plurality of reception points.

43. A vehicle passenger compartment proximity sensor system comprising:

a plurality of capacitive sensors in a seat in a vehicle passenger compartment measuring capacitance at a plurality of laterally-spaced points in the vehicle passenger compartment;

a seat position sensor determining a position of the seat relative to the vehicle passenger compartment; and

a controller determining a position of an occupant relative to the seat based upon the capacitance measured at the plurality of points and determining the position of the occupant relative to the vehicle passenger compartment based upon the position of the occupant relative to the seat and based upon the position of the seat relative to the vehicle passenger compartment.

44. The system of claim 43 wherein at least one of the plurality of capacitive sensors is laterally spaced from an other one of the plurality of capacitive sensors.

45. The system of claim 43 wherein the plurality of capacitive sensors measure capacitance of the plurality of points on a seating surface of the seat.