Glove detection/adjustment of sensitivity for capacitive sensing button and slider elements

• US 9,671,894 B2
• Filed: 06/04/2012
• Issued: 06/06/2017
• Est. Priority Date: 06/04/2012
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive GmbH (Continental AG)
• Inventors: Schenkewitz, Christian
• Primary Examiner(s): REGN, MARK W
• Application Number:
  US14/405,331
• Publication Number:
  US 20150123937A1
• Time in Patent Office: 1,828 Days
• Field of Search: 345174
• CPC Class Codes: B60K 2360/141 Activation of instrument input devices by approaching fingers or pens
• CPC Class Codes: B60K 2360/1446 Touch switches
• CPC Class Codes: B60K 2360/566 Mobile devices displaying vehicle information
• CPC Class Codes: B60K 2370/141 Activation by approaching fingers or pens
• CPC Class Codes: B60K 2370/1446 Touch switches
• CPC Class Codes: B60K 2370/566 Mobile devices displaying vehicle information
• CPC Class Codes: B60K 35/10 Input arrangements, i.e. from user to vehicle, associated with vehicle functions or specially adapted therefor
• CPC Class Codes: B60K 35/80 Arrangements for controlling instruments
• CPC Class Codes: G06F 2203/04101 2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: H03K 17/955 using a capacitive detector
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2217/94026 Automatic threshold calibration; e.g. threshold automatically adapts to ambient conditions or follows variation of input

Abstract

An input device for a control system of a vehicle includes at least one capacitive-sensing button, an actuation detection electrical circuit, a proximity sensor, a proximity temperature sensor, and a processor. In use, the capacitive-sensing button receives an actuation from a user. The actuation alters a capacitance value of the button. The detection electrical circuit comprises a threshold value and it outputs a button actuation signal when the capacitance value exceeds the threshold value. The proximity sensor generates a proximity signal when an object is provided near the capacitive-sensing button. The proximity temperature sensor provides a temperature measurement of the nearby area. The processor adjusts the threshold value to an adjustment value that is derived from the comparison signal.

Claims

1. An input device for a control system of a vehicle, the input device comprising:

at least one capacitive-sensing button, the at least one capacitive-sensing button being configured to receive an actuation from a user, wherein the actuation alters a capacitance value of the at least one capacitive-sensing button;

an actuation detection electrical circuit having a threshold value, wherein the actuation detection electrical circuit outputs a button actuation signal when the sensed capacitance value exceeds the threshold value;

a proximity sensor configured to generate a proximity signal when an object is in an area that is near the capacitive-sensing button;

a proximity temperature sensor configured to provide a temperature measurement of the area that is near the capacitive-sensing button; and

a processor, comprising;

a comparison unit configured to receive the temperature measurement and the proximity signal, wherein the comparison unit generates a comparison signal that is derived from the temperature measurement and from the proximity signal, and

an adjustment unit configured to adjust the threshold value to an adjustment value that is derived from the comparison signal,

wherein an ambient temperature is derived by the processor from previous temperature measurements from the proximity temperature sensor, or from a second temperature sensor, over a predetermined period of time,

wherein the comparison unit generates a pre-determined low sensitivity threshold comparison signal when the temperature measurement of the proximity temperature sensor exceeds the derived ambient temperature, and, based on the pre-determined low sensitivity threshold comparison signal, the adjustment unit changes the threshold value to a pre-determined low sensitivity threshold value, and

wherein the comparison unit generates a pre-determined high sensitivity threshold comparison signal when the temperature measurement of the proximity temperature sensor is substantially the same as the derived ambient temperature, and, based on the pre-determined high sensitivity threshold comparison signal, the adjustment unit changes the threshold value to a pre-determined high sensitivity threshold value.

2. The input device according to claim 1, wherein the capacitive-sensing button is configured to provide the proximity sensor signal.

3. The input device according to claim 1, wherein

the comparison unit has a module configured to generate the comparison signal based on a predetermined mathematical comparison function of the temperature measurement and of the proximity signal.

4. The input device according to claim 1, wherein

the comparison unit has a module configured to generate the comparison signal that comprises a value selected from a set of pre-determined comparison values based on the temperature measurement and on the proximity signal.

5. The input device according to claim 1, wherein

the adjustment unit has a module configured to determine the adjustment value based on a predetermined mathematical adjustment function of the comparison signal.

6. The input device according to claim 1, wherein

the adjustment unit has a module configured to select the adjustment value from a set of pre-determined comparison values based on the comparison signal.

7. The input device according to claim 1, wherein

the previous temperature measurements used to derive the ambient temperature are provided by the second temperature sensor.

8. The input device according to claim 1, wherein

the previous temperature measurements used to derive the ambient temperature are provided by the proximity temperature sensor.

9. A control module of a vehicle comprising:

an input device according to claim 1 configured to receive an actuation from a user and to output a button actuation signal; and

a control unit having a set of predetermined system function selection signals, the control unit being configured to receive the button actuation signal from the input device and to provide a system function selection signal selected from the set of pre-determined system function selection signals, the selection being provided according to the button actuation signal.

10. The control module according to claim 9, wherein the control module is configured to provide a radio function selection signal to a radio of a vehicle.

11. The control module according to claim 9, wherein the control module is configured to provide an air conditioning selection signal to an air conditioning unit of a vehicle.

12. The control module according to claim 9, wherein the control module is configured to provide a navigation function selection signal to a navigation unit of a vehicle.

13. A method of operating an input device for a control system of a vehicle, the method comprising:

generating a proximity signal when an object is provided in an area that is near a capacitive-sensing button;

obtaining a temperature measurement in the area that is near the capacitive-sensing button when the proximity signal is generated;

deriving an ambient temperature based upon previous temperature measurements in the area that is near the capacitive-sensing button;

comparing the temperature measurement obtained at the obtaining step against the derived ambient temperature;

selecting a button actuation threshold value from a set of pre-determined threshold values according to the comparison between the temperature measurement obtained at the obtaining step and the derived ambient temperature; and

adjusting a threshold value of an actuation detection electrical circuit of the capacitive-sensing button according to the button actuation threshold value such that;

a low sensitivity threshold value is set when the temperature obtained at the obtaining step exceeds the derived ambient temperature, and

a pre-determined high sensitivity threshold is set when the temperature obtained at the obtaining step is substantially the same as the derived ambient temperature.