Proximity switch assembly and activation method

• US 9,660,644 B2
• Filed: 04/11/2012
• Issued: 05/23/2017
• 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: Rankin, James Stewart, Majkowski, Matthew, Buttolo, Pietro, Gardner, Cornel Lewis, Salter, Stuart C.
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Barnett, Joel
• Application Number:
  US13/444,374
• Publication Number:
  US 20130270896A1
• Time in Patent Office: 1,868 Days
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 2217/94052 with evaluation of actuation pattern or sequence, e.g. tapping
• CPC Class Codes: H03K 2217/960705 Safety of capacitive touch and proximity switches, e.g. increasing reliability, fail-safe

Abstract

A proximity switch assembly and method for detecting activation of a proximity switch assembly is provided. The assembly includes a plurality of proximity switches each having a proximity sensor 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 and determines a differential change in generated signal, and further generates an activation output when the differential signal exceeds a threshold. The control circuitry further distinguishes an activation from an exploration of the plurality of switches and may determine activation upon detection of a stable signal.

Claims

1. A method of activating a proximity switch comprising:

generating an activation field for each of a plurality of proximity sensors;

monitoring with a controller amplitude of a signal generated in response to each of the activation fields;

providing an exploration mode;

determining a base level at a peak value or a substantially stable amplitude of one signal during a user touch interaction in the exploration mode; and

generating an activation output when the one signal subsequently is substantially stable and exceeds the base level by a differential change in the signal during the same user touch interaction.

2. The method of claim 1 further comprising determining a first value at the base level, determining a second value at a threshold, and determining the differential change in the generated one signal based on a difference between the first value and the second value.

3. The method of claim 2, wherein the threshold comprises a signal threshold for determining activation of the switch.

4. The method of claim 2, wherein the threshold comprises the peak value of the one signal during the user touch interaction.

5. The method of claim 2, wherein the first value comprises a first time and the second value comprises a second time, wherein the differential change in the generated signal comprises the difference in time between the first time and the second time.

6. The method of claim 5, wherein the differential change in generated signal is compared to a predetermined time period, and wherein an activation output is generated when the differential signal exceeds the difference in time.

7. The method of claim 1, wherein a plurality of activation fields are generated for the plurality of proximity sensors, and wherein the largest amplitude signal associated with the plurality of activation fields is processed to determine activation of one of the proximity sensors.

8. The method of claim 7, wherein the method further processes the plurality of activation fields to determine interaction with the plurality of sensors which enables a user to explore the plurality of proximity sensors in the exploration mode without activating the proximity switch.

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

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

11. A proximity switch assembly comprising:

a plurality of proximity switches each comprising a proximity sensor 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, detecting a first peak value or a substantially stable amplitude of the largest signal during a user touch interaction while in an exploration mode, establishing a base level at the determined peak value or stable amplitude, and generating an activation output when the signal is substantially stable and is greater than the base level by a differential signal during the same user touch interaction.

12. The switch assembly of claim 11, wherein the control circuitry determines a first value at the base level, determines a second value at a threshold, and determines the differential change in the generated signal based on a difference between the first value and the second value.

13. The switch assembly of claim 12, wherein the threshold comprises a signal threshold for determining activation of the switch.

14. The switch assembly of claim 12, wherein the second threshold comprises the peak value of the signal during the user touch interaction.

15. The switch assembly of claim 12, wherein the first value comprises a first time and the second value comprises a second time, wherein the differential change in the generated signal comprises the difference in time between the first time and the second time.

16. The switch assembly of claim 15, wherein the differential change in generated signal is compared to a predetermined time period, and wherein an activation output is generated when the differential signal exceeds the difference in time.

17. The switch assembly of claim 11, wherein a plurality of activation fields are generated for a plurality of proximity sensors, and wherein a largest amplitude signal associated with the plurality of activation fields is processed to determine activation of one of the proximity sensors.

18. The switch assembly of claim 11, wherein the plurality of proximity switches are installed in a vehicle for use by a passenger of the vehicle.

19. The switch assembly of claim 11, wherein the plurality of proximity switches comprises a plurality of capacitive switches each comprising one or more capacitive sensors.

20. A method of activating a proximity switch comprising:

generating an activation field with a plurality of proximity sensors;

monitoring with a controller amplitude of a signal generated in response to each of the activation fields;

determining a base level at a peak value of one signal during a user touch interaction in an exploration mode; and

generating an activation output when the one signal subsequently exceeds the base level by a differential change in the signal during the same user touch interaction.