LOCK DEVICE HAVING POSITION SENSOR

• US 20180038159A1
• Filed: 10/17/2017
• Published: 02/08/2018
• Est. Priority Date: 05/13/2014
• Status: Active Grant

• Current Assignee: Schlage Lock Company LLC (Allegion PLC)
• Original Assignee: Schlage Lock Company LLC (Allegion PLC)
• Inventors: Kincaid, Ryan C., Focke, Gabriel D., Telljohann, Brian A., Rettig, Raymond F., Dexter, Matthew, Rayburn, Ryne
• Granted Patent: US 10,227,818 B2
• Time in Patent Office: Days
• CPC Class Codes: E06B 7/28 Other arrangements on doors or windows, e.g. door-plates, windows adapted to carry plants, hooks for window cleaners edge protecting devices for door leaves E06B3/88; special glazing; emergency glazing; double glazing E06B3/66
• CPC Class Codes: G01B 7/14 for measuring distance or clearance between spaced objects or spaced apertures G01B7/30 takes precedence
• CPC Class Codes: G08B 13/08 by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind
• CPC Class Codes: G08B 29/181 due to failing power supply

Abstract

A position sensing system and method for detecting the displacement of a door from a reference position, such as, for example, from a closed position. The system includes a magnetometer that may be operably connected to the door, and which measures positional location relative to a reference magnetic field, such as, for example, a magnetic field provided by a magnet of a lock device. The system may also include an accelerometer that detects acceleration of the door, and thereby provides an indication of when location is to be measured by the magnetometer. Measurement information from the magnetometer is used to derive a position indicator that is compared to a reference indicator, the reference indicator being associated with the reference position. Differences between the position and reference indicators may provide an indication that the door has been moved from the reference position.

Claims

1. A lock device, comprising:

a magnet, the magnet providing a reference magnetic field;

a magnetometer structured to measure a location of the magnetometer relative to the reference magnetic field; and

a processing device structured to execute instructions stored on a non-transitory computer readable medium that cause the processing device to;

receive the location measurement of the magnetometer;

derive a position indicator from the location measurement of the magnetometer;

compare the position indicator to a reference indicator, the reference indicator corresponding to the location of the magnetometer when the magnetometer is at a reference position; and

determine, based on the comparison of the position indicator to the reference indicator, whether the magnetometer is at the reference position.

2. The lock device of claim 1, further including an accelerometer structured to detect an acceleration of the lock device, the processing device being further structured to generate a signal to wake-up the magnetometer from a low power mode in response to detection of the acceleration.

3. The lock device of claim 1, further including a door strike, and wherein the magnet is operably connected to the door strike.

4. The lock device of claim 2, wherein the accelerometer and the magnetometer are included in the same chip.

5. The lock device of claim 1, wherein the lock device includes a latching mechanism having at least one of a latch and a deadbolt.

6. The lock device of claim 1, wherein the processing device is structured to transmit, via a wireless transceiver, a status message to an access control system, wherein the status message indicates whether the magnetometer has been displaced from the reference position.

7. The lock device of claim 1, wherein the location measured by the magnetometer is a plurality of scalar values along two or more axes.

8. The lock device of claim 1, wherein the position indicator is a sum value of the measurements of the location measured by the magnetometer.

9. The lock device of claim 1, wherein the processing device is adapted to issue a polling signal to the magnetometer at predetermined time intervals.

10. A position sensing system for detecting the displacement of a door from a closed position, the position sensing system comprising:

a lock device having a latch mechanism and a door strike;

a magnet, the magnet providing a reference magnetic field;

a sensor having a magnetometer and an accelerometer, the magnetometer configured to measure a location of the magnetometer relative to the reference magnetic field, the accelerometer configured to detect an acceleration of the door; and

a processing device structured to derive a position indicator from the location measured by the magnetometer, the processing device further configured to compare the position indicator to a reference indicator, the reference indicator indicative of the location of the magnetometer when the door is in the closed position.

11. The position sensing system of claim 10, wherein the sensor is operably mounted to the door.

12. The position sensing system of claim 11, wherein the magnet is operably connected to the door strike.

13. The position sensing system of claim 10, wherein the magnetometer is operably connected to a relatively static structure adjacent to the door, and wherein the magnet is operably connected to the door.

14. The position sensing system of claim 10, further including a transceiver configured to receive a signal from the processing device indicative of the position indicator being different than the reference indicator, and wherein the transceiver is configured to transmit a status signal indicative of there being a difference between the position and reference indicators to an access control system.

15. The position sensing system of claim 10, wherein the processing device is further configured to generate, at predetermined time intervals, a polling signal to wake the magnetometer from a lower power mode.

16. A method for determining whether a door has been displaced from a reference position, the method comprising:

measuring a reference location of a magnetometer relative to a reference magnetic field when the door is at the reference position;

deriving, by a processing device of a lock device, a reference indicator from the measured reference location;

recording in the memory of the lock device the reference indicator;

measuring, by the magnetometer, a position location of the magnetometer relative to the reference magnetic field;

deriving, by the processing device, a position indicator from the measured position location;

comparing, by the processing device, the position indicator and the reference indicator; and

determining, by the processing device, from the comparison of the position and reference indicators whether the door has been displaced from the reference position.

17. The method of claim 16, further comprising delivering a polling signal to the magnetometer to wake the magnetometer from a low power mode, and, whereupon awakening, the method further comprises measuring, by the magnetometer, a position location;

and

wherein the delivering the polling signal includes delivering the polling signal to wake the magnetometer upon one of i) an acceleration provided by an accelerometer; and

ii) a change in door position.

18. The method of claim 17, wherein the measuring the position location includes obtaining a plurality of sets of measurements of the position location, each of the plurality of sets of measurements having two or more scalar values indicative of the location of the magnetometer relative to the reference magnetic field.

19. The method of claim 16, further comprising filtering the plurality of sets of measurements of the position location.

20. The method of claim 19, wherein the filtering removes at least one high frequency noise.