Lock device having position sensor

Patent metadata

Field	Value
Publication number	US-9790736-B2
Application number	US-201514711414-A
Country	US
Kind code	B2
Filing date	May 13, 2015
Priority date	May 13, 2014
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

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.

First claim

The invention claimed is:

1. A lock device for a door having an open position, a closed position, and positions therebetween with respect to an adjacent structure defining an entryway, the lock device comprising:
a magnet, the magnet providing a reference magnetic field, the magnet being located at one of the door and the adjacent structure;
a magnetometer structured to measure a location of the magnetometer relative to the magnet as provided by the reference magnetic field, the magnetometer being located at the other of the door and the adjacent structure;
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; and
a processing device structured to execute instructions stored on a non-transitory computer readable medium that causes the processing device to:
receive the location measurement of the magnetometer;
derive a position indicator from the location measurement of the magnetometer, wherein the position indicator indicates one of the positions of the door with respect to the adjacent structure;
compare the position indicator to a reference indicator, the reference indicator corresponding to the location of the magnetometer with respect to the magnet 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 a door strike, and wherein the magnet is operably connected to the door strike.

3. The lock device of claim 1 , wherein the accelerometer and the magnetometer are included in the same chip.

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

5. 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.

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

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

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

9. A position sensing system for detecting the displacement of a door from a closed position to an open position and to a positions therebetween with respect to an adjacent structure defining an entryway, 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, wherein the magnet is located at one of the door and the adjacent structure;
a sensor located at the other of the door and the adjacent structure, the sensor having a magnetometer and an accelerometer, the magnetometer configured to measure a location of the magnetometer relative to the reference magnetic field provided by the magnet, the accelerometer configured to detect an acceleration of the door based on the reference magnetic field provided by the magnet, wherein the accelerometer upon detecting the acceleration of the door generates a wake-up command to cause the magnetometer to measure the location of the magnetometer relative to the reference magnetic field; and
a processing device structured to derive a position indicator of the door in one of the open position, the closed position, and positions therebetween, 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.

10. The position sensing system of claim 9 , wherein the sensor is operably mounted to the door.

11. The position sensing system of claim 10 , wherein the magnet is operably connected to the door strike.

12. The position sensing system of claim 9 , wherein the magnetometer is operably connected to the adjacent structure adjacent to the door, and wherein the magnet is operably connected to the door.

13. The position sensing system of claim 9 , 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.

14. The position sensing system of claim 9 , 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.

15. A method for determining whether a door has been displaced from a reference position, wherein the reference position is one of an open position, a closed position, and a position located between the open position and the closed position, the method comprising:
measuring a reference location of a magnetometer relative to a reference magnetic fields provided by a magnet 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;
delivering polling signal to the magnetometer to wake the magnetometer from a low power mode upon an acceleration provided by an accelerometer;
measuring, by the magnetometer, a position location of the magnetometer relative to the reference magnetic field provided by the magnet;
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 to one of the open position, the closed position, and the position located between the open position and the closed position.

16. The method of claim 15 , whereupon awakening, the method further comprises measuring, by the magnetometer, the position location.

17. The method of claim 16 , 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.

18. The method of claim 15 , further comprising filtering the plurality of sets of measurements of the position location.

19. The method of claim 18 , wherein the filtering removes at least one high frequency noise.

20. A method for determining whether a door has been displaced from a reference position, wherein the reference position is one of an open position, a closed position, and a position located between the open position and the closed position, the method comprising:
measuring a reference location of a magnetometer relative to a reference magnetic field provided by a magnet when the door is at the reference positi

Assignees

• Schlage Lock Co Llc

Inventors

• Kincaid Ryan C
• Focke Gabriel D
• Telljohann Brian A
• Rettig Raymond F
• Dexter Matthew
• Rayburn Ryne

Classifications

• G08B29/181

  due to failing power supply · CPC title

• G08B13/08 Primary

  by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind · CPC title

• G01B7/14

  for measuring distance or clearance between spaced objects or spaced apertures (G01B7/30 takes precedence) · CPC title

• E06B7/28 Primary

  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 title