System and method for sensing loads

• US 20080234898A1
• Filed: 03/23/2007
• Published: 09/25/2008
• Est. Priority Date: 03/23/2007
• Status: Active Grant

• Current Assignee: Patricia Wiener
• Original Assignee: Patricia Wiener
• Inventors: Wiener, Patricia
• Granted Patent: US 8,209,092 B2
• Time in Patent Office: Days
• US Class Current: 701/45
• CPC Class Codes: B60R 21/01534 using electromagneticwaves, e.g. infrared
• CPC Class Codes: G01G 19/4142 for controlling activation of safety devices, e.g. airbag systems electrical circuits for triggering safety arrangements in case of vehicle accidents B60R21/015
• CPC Class Codes: G01G 3/125 wherein the weighing element is an optical member
• CPC Class Codes: G01L 1/243 using means for applying force perpendicular to the fibre axis

Abstract

An optical sensing system detects pressure through attenuation of light in an optical fiber. This is particularly useful for measuring the weight and position of a load on a mat including multiple such optical fibers, which may be positioned in an automobile seat to determine theses parameters for a passenger in that seat. This information can be presented to an airbag deployment system in a form that will easily enable the airbag to be deployed (when needed) in a manner sensitive to the weight and position of the occupant. It provides based on this detection system a technique to suppress airbag deployment based on passenger profile. Further, the system and method use an optical fabric methodology such that loads, load movement, load position can be detected in vehicles. In applications for vehicles such as aircraft or boats, sensing weight, position and movement of cargo can warn an operator or pilot in sufficient time to correct dangerous shifts in weight within the cargo portion of the vehicle or to modify the operation of the vehicle to compensate for such shifts.

Claims

1. An optical sensing system for detecting pressure exerted by a mass through attenuation of light in an optical fiber comprising:

a matrix including a plurality of optical fibers;

a support element against which the plurality of optical fibers can move, such that a bend is created in at least one of the optical fibers as a result of the pressure exerted by the object;

a light source for sending light beams through the plurality of optical fibers; and

a detector for measuring the attenuation in the light beam sent through the at least one optical fiber.

2. The optical sensing system of claim 1 wherein the plurality of fibers further comprise a first group containing a first and a second optical fiber, and a second group containing a third and a fourth optical fiber.

3. The optical sensing system of claim 2 wherein the first group and the second group are approximately parallel.

4. The optical sensing system of claim 1, wherein the pressure results from the weight of the mass, and further comprising:

a processor configured to derive the weight of the mass from the attenuation of the light beam in the at least one optical fiber.

5. The optical sensing system of claim 4, further comprising a seat for containing the matrix and the support element.

6. The optical sensing system of claim 5 wherein the seat is an automobile seat.

7. The optical sensing system of claim 4, further comprising a memory for storing information about the derived weight at a first time and at a second time.

8. The optical sensing system of claim 4, further comprising means for providing the derived weight to an airbag deployment system.

9. The optical sensing system of claim 4, wherein the processor is further configured to derive the position of the mass from the attenuation of the light beam in the at least one optical fiber.

10. The optical sensing system of claim 9, further comprising means for providing the derived position to an airbag deployment system.

11. The optical sensing system of claim 4, further comprising means for setting a tare reference weight value.

12. The optical sensing system of claim 4, further comprising means for differentiating whether the mass has a fixed or dynamic weight.

13. A method for measuring the weight of a mass resting on an object, comprising:

providing an optical fiber in the object such that a change in pressure on the object causes deformation of the optical fiber;

sending a light beam through the optical fiber;

measuring the attenuation of light in the optical fiber; and

deriving the weight of the mass located on the object from the attenuation of the light in the optical fiber.

14. The method of claim 13 further comprising deriving the position of the mass on the object from the attenuation of the light in the optical fiber.

15. The method of claim 13 further comprising deriving the weight of the mass at a first time and at a second time.

16. The method of claim 15 further comprising deriving the difference in the mass between the first time and the second time.

17. The method of claim 15, wherein the first time is a time in which there is no mass located on the object.

18. The method of claim 14 further comprising providing the derived weight and position of the mass on the object to an airbag deployment system.

19. The method of claim 14 wherein the weight of the mass is derived at a time close to the time when the position of the mass is derived.

20. The method of claim 19 further comprising providing the derived weight and position to an airbag deployment system.

21. The method of claim 19 wherein deriving the weight and position of the mass is completed in less than approximately 1 millisecond.

22. The method of claim 18 further comprising controlling the rate and extent of deployment of an airbag based at least in part upon the derived weight and position.

23. The method of claim 18 wherein the object is an automobile seat.

24. The method of claim 23 further comprising detecting whether a seatbelt is in use on the automobile seat, and wherein controlling the rate and extent of deployment of the airbag is based at least in part upon whether the seatbelt is in use.

25. The method of claim 18 further comprising establishing thresholds for the airbag deployment system at which an airbag will deploy based at least in part upon the derived weight and position.

26. The method of claim 25 wherein the object is an automobile seat.

27. The method of claim 26 further comprising detecting whether a seatbelt is in use on the automobile seat, and wherein establishing thresholds is based at least in part upon whether the seatbelt is in use.

28. The method of claim 27 further comprising detecting the position of the automobile seat relative to the front of the automobile, and wherein establishing thresholds and controlling the rate and extent of deployment of the airbag are each based at least in part upon the detected position of the automobile seat.

29. The method of claim 23 further comprising providing the derived weight and position of the mass on the automobile seat to a front airbag deployment mechanism.

30. The method of claim 23 further comprising providing the derived weight and position of the mass on the automobile seat to a side airbag deployment mechanism.