Pressure sensor including a pressure sensitive material for use with control systems and methods of using the same

• US 9,727,031 B2
• Filed: 04/15/2013
• Issued: 08/08/2017
• Est. Priority Date: 04/13/2012
• Status: Active Grant

• Current Assignee: Joyson Safety Systems Acquisition, LLC
• Original Assignee: TK Holdings Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Lisseman, Jason, Andrews, David, Van'tZelfde, Dwayne
• Primary Examiner(s): Ali, Mohammad
• Assistant Examiner(s): Kabir, Saad M
• Application Number:
  US13/863,363
• Publication Number:
  US 20130338847A1
• Time in Patent Office: 1,576 Days
• Field of Search: None
• CPC Class Codes: G05B 11/01 electric
• CPC Class Codes: G06F 3/04144 using an array of force sensing means position sensing using the local deformation of sensor cells G06F3/0447
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: H03K 17/9625 using a force resistance transducer

Abstract

Various embodiments of pressure sensors send a plurality of control messages to a system controller. An example pressure sensor may include: a base; at least first and second conductors; a pressure sensitive material at least partially intervening between the first and second conductors; a memory; a clock; and a processor. The pressure sensitive material may have a composition configured to continuously change at least one electrical property. The processor may be configured to determine a first electrical property using the first and second conductors, associate the first electrical property with a time from the clock and write the first electrical property and the time to the memory. The processor may also be configured to calculate a time-based change in the first electrical property, correlate the time-based change with at least one of the control messages and communicate the at least one of the control messages to the system controller.

Claims

1. A pressure sensor for sending a plurality of control messages to a system controller, the pressure sensor comprising:

a base;

at least a first conductor and a second conductor;

a pressure sensitive material supported by the base and at least partially intervening between the first and second conductors and having a composition configured to continuously change at least one electrical property of the pressure sensitive material in response to an applied force, wherein a conductive or electrical characteristic of the pressure sensor is configured to change based on a change in the at least one electrical property of the pressure sensitive material, and wherein the conductive or electrical characteristic of the pressure sensor is further configured to change based on a material, physical dimension, or arrangement of at least one of the first conductor, the second conductor, or the pressure sensitive material;

a memory;

a clock; and

a processor connected in communication with the first and second conductors, the memory and the clock, the processor configured to determine a first electrical property of the pressure sensitive material using the first and second conductors and associate the first electrical property with a time from the clock and to write the first electrical property associated with the time to the memory;

the processor further configured to read the first electrical property and the time from the memory and to calculate a time-based change in the first electrical property;

the processor further configured to correlate the time-based change in the first electrical property with at least one of the control messages and to communicate the at least one of the control messages to the system controller, wherein the at least one electrical property is resistance, wherein resistance values of the pressure sensitive material define a predictable resistance-force response curve in response to varying amounts of applied force, and wherein the resistance values of the pressure sensitive material vary between 10¹²Ω

±

10 percent and 1Ω

±

10 percent between 0 N and 10 N.

2. The pressure sensor of claim 1, wherein the at least one electrical property is continuously variable in relation to an amount of applied force.

3. The pressure sensor of claim 2, wherein the at least one electrical property is capable of changing in response to a change in the amount of applied force.

4. The pressure sensor of claim 1, wherein the predictable resistance-force response curve is defined by a power log function curve.

5. The pressure sensor of claim 4, wherein the power log function curve is Resistance=1732.8×

Applied Force^−

0.739.

6. The pressure sensor of claim 1, wherein a resistance value of the pressure sensitive material is 5 kΩ

±

10 percent when the amount of applied force is 1 N and a resistance value of the pressure sensitive material is 1.5 kΩ

±

10 percent when the amount of applied force is approximately 3 N.

7. The pressure sensor of claim 1, wherein the pressure sensitive material comprises a single contiguous layer at least partially intervening between the first and second conductors.

8. The pressure sensor of claim 1, further comprising a third conductor wherein the pressure sensitive material at least partially intervenes between pairs of the conductors.

9. The pressure sensor of claim 8, wherein the processor is connected in communication with the third conductor and is configured to determine a second electrical property using the third conductor.

10. The pressure sensor of claim 9, further comprising a fourth conductor, wherein the processor is connected in communication with the fourth conductor and is configured to determine the second electrical property using the fourth conductor.

11. The pressure sensor of claim 10, wherein the processor is further configured to determine a position of the amount of pressure on the pressure sensitive material using the first and second electrical properties.

12. The pressure sensor of claim 11, wherein the processor is further configured to associate the position with the time from the clock and to write the position associated with the time to the memory.

13. The pressure sensor of claim 12, wherein the processor is configured to read the position and the time from the memory and to calculate a time-based change to the position.

14. The pressure sensor of claim 13, wherein the processor is configured to correlate the time-based change in the position with the at least one of the control messages.

15. The pressure sensor of claim 14, wherein the processor is configured to determine and write to the memory a series of associated positions, first electrical properties and times to the memory.

16. The pressure sensor of claim 15, wherein the processor is configured to determine a path and pressure contour from the series.

17. The pressure sensor of claim 16, wherein the processor is further configured to determine whether the path and pressure contour meet a swipe threshold.

18. The pressure sensor of claim 17, wherein the processor is further configured to correlate the swipe threshold with the at least one of the control messages.

19. The pressure sensor of claim 1, wherein the processor is configured to determine whether the time-based change in the first electrical property exceeds a threshold associated with the amount of pressure.

20. The pressure sensor of claim 19, wherein the processor is configured to determine whether a time comparison between the time from the memory and a second time meets a time threshold.

21. The pressure sensor of claim 20, wherein the processor is configured to use meeting of the pressure and time thresholds as preconditions to communication of the at least one of the control messages.

22. The pressure sensor of claim 21, wherein the processor is further configured to correlate meeting of the thresholds with at least one of the control messages.

23. The pressure sensor of claim 20, wherein the processor is further configured to classify the time-based change as a tap if the time comparison is less than the time threshold and to classify the time-based change as a hold if the time comparison is more than the time threshold.

24. The pressure sensor of claim 23, wherein the processor is further configured to correlate whether the time-based change is the tap or the hold with the at least one of the control messages.

25. The pressure sensor of claim 1, wherein the pressure sensitive material has a plurality of zones and each of the zones is connected to a pair of conductors.

26. The pressure sensor of claim 25, wherein the processor is connected to the pairs of conductors and configured to determine the first electrical property of each of the zones using the pairs of conductors.

27. The pressure sensor of claim 26, wherein the processor is further configured to associate the first electrical property and to write the first electrical property associated with each of the zones to the memory.

28. The pressure sensor of claim 27, wherein the processor is configured to read the first electrical property associated with each of the zones from memory and to calculate the time-based change in the first electrical property using the first electrical property associated with each of the zones.

29. The pressure sensor of claim 28, wherein the zones are defined by separate portions of the pressure sensitive material.

30. The pressure sensor of claim 28, wherein at least two of the zones overlap.

31. The pressure sensor of claim 29, wherein one or more of the zones form at least one of a strip, a grid, a radius, a spaced array and a button.

32. The pressure sensor of claim 28, further comprising a cover defining portions corresponding to the zones.

33. The pressure sensor of claim 32, wherein each of the cover portions includes indicia associated with at least one of the control messages.

34. The pressure sensor of claim 1, further comprising a force concentrator positioned against the pressure sensitive material.

35. The pressure sensor of claim 34, further comprising a cover, wherein the force concentrator is positioned between the cover and the pressure sensitive material.