PROXIMITY SWITCH ASSEMBLY AND METHOD HAVING ADAPTIVE TIME DELAY

• US 20130271202A1
• Filed: 04/11/2012
• Published: 10/17/2013
• Est. Priority Date: 04/11/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Buttolo, Pietro, Salter, Stuart C., Gardner, Cornel Lewis, Goodson, Thomas Lee, Rankin, James Stewart
• Granted Patent: US 9,065,447 B2
• Time in Patent Office: Days
• US Class Current: 327/517
• CPC Class Codes: H03K 17/94 characterised by the way in which the control signals are generated
• CPC Class Codes: H03K 17/955 using a capacitive detector

Abstract

A proximity switch assembly and method for detecting activation of the proximity switch assembly is provided. The assembly includes a plurality of proximity switches each providing a sense activation field and control circuitry processing the activation field of each proximity switch to sense activation. The control circuitry monitors the signal responsive to the activation field, determines a rate of change in signal amplitude for each signal, and generates an adaptive time delay based on the control circuitry. The control circuitry further detects a peak amplitude of the signal and determines activation of the switch after expiration of the time delay following the peak amplitude detection.

Claims

1. A method for detecting activation of a proximity switch comprising:

generating an activation field with a proximity sensor;

monitoring a signal responsive to the activation field;

generating an adaptive time delay based on a rate of change of the monitored signal;

detecting a peak amplitude of the signal; and

determining activation of the switch after expiration of the time delay following the peak amplitude detection.

2. The method of claim 1, wherein the step of generating the adaptive time delay comprises determining a time period for the signal to increase from a first threshold to a second threshold.

3. The method of claim 2, wherein the second threshold comprises the peak amplitude.

4. The method of claim 2, wherein the adaptive time delay further comprises an additional delay time.

5. The method of claim 1, wherein the step of determining activation comprises comparing the monitored signal to a threshold and determining activation if the monitored signal exceeds the threshold after the expiration of the time delay.

6. The method of claim 1, wherein the proximity switch is installed on a vehicle for use by a passenger in the vehicle.

7. The method of claim 1, wherein the proximity switch comprises a capacitive switch comprising one or more capacitive sensors.

8. A method for detecting activation of a proximity switch comprising:

generating activation fields with a plurality of proximity sensors associated with a plurality of proximity switches;

monitoring a signal responsive to each of the activation fields;

determining a rate of change in signal amplitude for each signal;

generating an adaptive time delay based on the rate of change;

detecting a peak amplitude of the signal; and

determining activation of one of the proximity switches after expiration of the time delay following the peak amplitude detection.

9. The method of claim 8, wherein the step of determining activation of one of the proximity switches comprises comparing the monitored signal to a threshold signal and determining activation if the monitored signal exceeds the threshold after the expiration of the time delay.

10. The method of claim 9, wherein the step of generating the adaptive time comprises determining a time period for the signal to increase from a first threshold to a second threshold.

11. The method of claim 10, wherein the second threshold comprises the peak amplitude.

12. The method of claim 8, wherein the adaptive time delay further comprises an additional delay time.

13. The method of claim 8, wherein the proximity switch is installed on a vehicle for use by a passenger in the vehicle.

14. The method of claim 8, wherein the proximity switch comprises a capacitive switch comprising one or more capacitive sensors.

15. A proximity switch assembly comprising:

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

control circuitry processing the activation field of each proximity switch to sense activation, said control circuitry monitoring a signal responsive to the activation field, generating a rate of change in signal amplitude, detecting a peak amplitude of the signal, and determining activation of a switch after expiration of the adaptive time delay following the peak amplitude detection.

16. The switch assembly of claim 15, wherein the adaptive time delay is generated by a time period for the signal to increase from a first threshold to a second threshold.

17. The switch assembly of claim 16, wherein the second threshold comprises the peak amplitude.

18. The switch assembly of claim 15, wherein the step of determining activation of the switch comprises comparing the monitored signal to a threshold and determining activation if the monitored signal exceeds the threshold after the expiration of the time delay.

19. The switch assembly of claim 15, wherein the plurality of proximity switches are installed in a vehicle for use by a passengers of the vehicle.

20. The switch assembly of claim 15, wherein the plurality of proximity switches comprise a plurality of capacitive switches each comprising one or more capacitive sensors.