CAPACITOR SENSORS AND SYSTEM AND METHODS FOR NON-CONTACT OBJECT DETECTION

• US 20130127479A1
• Filed: 11/22/2011
• Published: 05/23/2013
• Est. Priority Date: 11/22/2011
• Status: Active Grant

• Current Assignee: Flextronics Automotive Inc
• Original Assignee: Flextronics Automotive Inc
• Inventors: Grills, Reginald C., Matkiwsky, Yarko, Warren, Gary, Chun, Allan, Tahir, Wasim, Steane, Steve Gary
• Granted Patent: US 9,068,816 B2
• Time in Patent Office: Days
• US Class Current: 324/684
• CPC Class Codes: E05F 15/46 responsive to changes in electrical capacitance
• CPC Class Codes: E05Y 2900/531 Doors
• CPC Class Codes: E05Y 2900/546 Tailboards, tailgates or sideboards opening upwards
• CPC Class Codes: G01B 7/14 for measuring distance or clearance between spaced objects or spaced apertures G01B7/30 takes precedence
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24

Abstract

A non-contact object detection system includes a capacitor sensor and a control system, the control system providing a AES (Adaptive Excitation Signal) to the capacitor sensor, the AES (Adaptive Excitation Signal) configured according to an environment in which the capacitor sensor is deployed, the AES (Adaptive Excitation Signal) configured to produce a threshold voltage from the capacitor sensor to the control system in the environment when an object is not in a detection area of the capacitor sensor.

Claims

1. A non-contact object detection system comprising:

(a) a capacitor sensor; and

(b) a control system, the control system providing a AES to the capacitor sensor, the AES configured according to an environment in which the capacitor sensor is deployed, the AES configured to produce a threshold voltage from the capacitor sensor to the control system in the environment when an object is not in a detection area of the capacitor sensor.

2. The non-contact object detection system of claim 1, wherein the capacitor sensor provides a detection voltage to the control system when an object is in the detection area.

3. The non-contact object detection system of claim 1, wherein the control system includes instructions for automatically configuring the AES and the control system is configured to execute the instructions.

4. The non-contact object detection system of claim 3, wherein the instructions include a module for determining whether the baseline voltage is within an upper baseline limit and a lower baseline limit of the capacitor sensor.

5. The non-contact object detection system of claim 4, wherein the instructions include a module for adjusting the AES according to the environment/closure position to achieve a desired base line profile to be within upper/lower limits.

6. The non-contact object detection system of claim 5 wherein the environment is a power closure system.

7. The non-contact object detection system claim 1, wherein the system is immune to water affecting sensor characteristics.

8. The non-contact object detection system claim 6, wherein the non-contact object detection system is integrated into the power closure system.

9. The non-contact object detection system claim 8, wherein the power closure system includes a proximity based speed control algorithm.

10. The non-contact object detection system claim 8, wherein the power closure system includes an object detection, recognition, and closure stoppage/reversal system.

11. The non-contact object detection system claim 8, wherein the power closure system includes a touch based anti-pinch system.

12. The non-contact object detection system of claim 2, further comprising:

(c) a modulator configured to receive a first clock signal from the control system, the modulator interconnected with the capacitor sensor;

(d) a synchronous demodulator configured to receive a first signal from the capacitor sensor, a second clock signal from the control system, and a third clock signal from the control system and demodulate the signal from the capacitor sensor; and

(e) an amplifier configured to amplify a second signal from the synchronous demodulator and provide an analog output signal to the control system, the analog output signal indicative of whether an object is in the detection area.

13. The non-contact object detection system of claim 1 wherein the capacitor sensor includes a guard and the guard is covered with an environmentally protective coating paint, the environmentally protective coating providing waterproofing to the sensor.

14. A method of detecting an object in a detection area of a capacitor sensor deployed in a closure, the method comprising:

providing a AES to the capacitor sensor from a control system;

sensing a detection voltage produced from the capacitor sensor;

comparing the detection voltage to a threshold voltage; and

based on the comparing determining whether the object is in the detection area.

15. The method of claim 14, further comprising:

automatically configuring the threshold voltage according to an instruction executed by the control system, the threshold voltage indicative of the voltage produced by the capacitor sensor when no object is present in the detection area.

16. The method of claim 15, wherein the instructions include adjusting the AES in order to set the threshold voltage between an upper and lower baseline for the capacitor sensor.

17. The method of claim 16, wherein the instructions include adjusting the AES to a lower frequency if the threshold voltage is not less than the upper baseline.

18. The method of claim 17, wherein the instructions include adjusting the AES to a higher frequency if the threshold voltage is not greater than the lower baseline.

19. The method of claim 18, wherein the instructions include providing an indication that the capacitor sensor is faulty if the AES cannot be adjusted to provide a threshold voltage between the upper and lower baseline.

20. A method of providing water immunity to a capacitor sensor:

(a) detecting a voltage dip due to a drop of water with a capacitor sensor;

(b) adjusting the capacitor sensor to a new frequency with sensor control electronics to compensate for the drop of water, the new frequency dependent on a sensor gain.