Proximity switch assembly having dynamic tuned threshold

• US 9,136,840 B2
• Filed: 05/17/2012
• Issued: 09/15/2015
• Est. Priority Date: 05/17/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Salter, Stuart C., Gardner, Cornel Lewis, Buttolo, Pietro
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): DOMINIQUE, EMMANUEL
• Application Number:
  US13/473,815
• Publication Number:
  US 20130307610A1
• Time in Patent Office: 1,216 Days
• Field of Search: 307/116
• US Class Current: 1/1
• CPC Class Codes: H03K 17/945 Proximity switches H03K17/96 takes precedence
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 2217/94026 Automatic threshold calibration; e.g. threshold automatically adapts to ambient conditions or follows variation of input

Abstract

A method of activating a proximity switch is provided. The method of activating the proximity switch includes the step of sensing a signal associated with a proximity sensor and sensing a dynamic parameter. The method also includes the step of tuning a threshold value based on the sensed dynamic parameter. The method further includes the step of activating the switch based on the signal and the threshold value.

Claims

1. A method of activating a proximity switch comprising:

sensing a signal associated with a proximity sensor;

sensing a dynamic motion parameter indicative of dynamic motion of the proximity switch;

tuning a threshold value of the switch based on the sensed dynamic motion parameter to allow improved switch activation during the sensed dynamic motion; and

activating the switch based on the signal and the tuned threshold value.

2. The method of claim 1, wherein the step of tuning the threshold value comprises changing a threshold value that is compared to the sensed signal.

3. The method of claim 2, wherein the step of tuning comprises increasing the threshold value when sufficient dynamic motion is detected.

4. The method of claim 2 further comprising the step of detecting a stable signal and activating the switch further based on the detected stable signal.

5. The method of claim 4, wherein the step of tuning the threshold value further comprises changing a time period that the signal is required to be at a substantially constant value, wherein the stable signal is compared to the time period to determine activation of the switch.

6. The method of claim 4, wherein the step of tuning the threshold value further comprises changing a signal range that the signal is required to be within for a time period to be stable, wherein the stable signal is compared to the signal range to determine activation of the switch.

8. The method of claim 1, wherein the step of sensing the dynamic motion parameter comprises sensing acceleration of a vehicle.

9. The method of claim 1, wherein the step of sensing the dynamic motion parameter comprises sensing a signal generated by one of vehicle braking, vehicle shocks, and vehicle steering wheel.

10. The method of claim 1, wherein the switch is located on a vehicle and the sensed dynamic motion parameter is dynamic motion of the vehicle.

7. A method of activating a proximity switch comprising:

sensing a signal associated with a proximity sensor;

sensing a dynamic parameter;

tuning a threshold value based on the sensed dynamic parameter comprising determining a ratio of a first signal associated with a first switch to a second signal associated with a second switch and changing the threshold value based on the ratio; and

activating the switch based on the signal and the threshold value.

11. A proximity switch assembly comprising:

a plurality of proximity switches each providing a sense activation field; and

control circuitry processing the activation field to sense a signal associated with a proximity sensor, sensing a dynamic motion parameter indicative of dynamic motion of the switch assembly, tuning a threshold value of the switch based on the sensed dynamic motion parameter to allow improved switch activation during the sensed dynamic motion, and activating the switch based on the signal and the tuned threshold value.

12. The proximity switch assembly of claim 11, wherein the step of tuning the threshold value comprises changing a threshold value that is compared to the sensed signal.

13. The proximity switch assembly of claim 12, wherein the step of tuning comprises increasing the threshold value when sufficient dynamic motion is detected.

14. The method of claim 12 further comprising the step of detecting a stable signal and activating the switch further based on the detected stable signal.

15. The proximity switch assembly of claim 14, wherein the step of tuning the threshold value further comprises changing a time period that the signal is required to be at a substantially constant value, wherein the stable signal is compared to the time period to determine activation of the switch.

16. The proximity switch assembly of claim 14, wherein the step of tuning the threshold value further comprises changing a signal range that the signal is required to be within for a time period to be stable, wherein the stable signal is compared to the signal range to determine activation of the switch.

17. The proximity switch assembly of claim 11, wherein the step of tuning the threshold value comprises determining a ratio of a first signal associated with a first switch to a second signal associated with a second switch and to changing the threshold value based on the ratio.

18. The proximity switch assembly of claim 11, wherein the step of sensing the dynamic motion parameter comprises sensing acceleration of a vehicle.

19. The proximity switch assembly of claim 11, wherein the step of sensing the vehicle dynamic motion parameter comprises sensing a signal generated by one of vehicle braking, vehicle shocks, and vehicle steering wheel.

20. The proximity switch assembly of claim 11, wherein the switch assembly is located on a vehicle and the sensed dynamic motion parameter is indicative of motion of the vehicle.