Lock device having position sensor

• US 10,227,818 B2
• Filed: 10/17/2017
• Issued: 03/12/2019
• 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
• Primary Examiner(s): Dsouza, Adolf
• Application Number:
  US15/786,015
• Publication Number:
  US 20180038159A1
• Time in Patent Office: 511 Days
• Field of Search: None
• 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 position sensing system for detecting the displacement of a door from a closed position relative to a door frame defined in a wall of a building structure, the position sensing system comprising:

a lock device having a housing, a latch mechanism, and a door strike, wherein at least a portion of the latch mechanism is positioned within the housing and the door strike is secured to the door frame, and wherein the latch mechanism is selectively extendable through the door strike to lock and unlock the door;

a magnet secured to the door frame, the magnet providing a reference magnetic field;

a sensor having a magnetometer, the magnetometer configured to measure a location of the magnetometer relative to the reference magnetic field; 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.

2. The position sensing system of claim 1, wherein the sensor is operably mounted to the door.

3. The position sensing system of claim 2, wherein the magnet is operably connected to the door strike.

4. The position sensing system of claim 1, 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.

5. The position sensing system of claim 1, 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.

6. A method for determining whether a door has been displaced from a reference position relative to a door frame defined in a wall of a building structure using a lock device secured to the door, the method comprising:

measuring, during calibration of the lock device, a reference location of a magnetometer relative to a reference magnetic field when the door is at the reference position, wherein the reference magnetic field is generated by a magnetized source device secured to the wall;

deriving, by a processing device of the 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 and subsequent to calibration of the lock device, a position location of the magnetometer relative to the door frame based on the sensed 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.

7. The method of claim 6, 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 an acceleration provided by an accelerometer.

8. The method of claim 7, wherein 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.

9. The method of claim 6, further comprising filtering the plurality of sets of measurements of the position location.

10. A door position sensing system for a door having an open position and a closed position relative to door frame defined in a wall of a building structure, the door position sensing system comprising:

a door strike secured to the door frame of the building structure and defining an orifice;

an electronic lock having a housing, a processing device, a memory, and a latch mechanism, wherein the processing device and at least a portion of the latch mechanism are contained within the housing, wherein the latch mechanism extends through the orifice of the door strike and into the door frame when the electronic lock is in a locked condition and the door is in the closed position, and wherein the latch mechanism is withdrawn from the door frame and the orifice when the electronic lock is in an unlocked condition;

a magnetized source device secured to the wall at the door frame and structured to generate a reference magnetic field; and

a magnetic field sensor positioned within the housing and configured to measure a magnetic field;

wherein the memory includes a plurality of instructions stored thereon that, in response to execution by the processing device, causes the electronic lock to;

calibrate the magnetic field sensor to store a plurality of reference indicators based on the sensed reference magnetic field, wherein the plurality of stored reference indicators includes first sensor data of the magnetic field sensor received when the door is in the closed position and second sensor data of the magnetic field sensor received when the door is in the open position;

generate at least one indicator based on sensor data of the magnetic field sensor associated with a sensed magnetic field;

compare the at least one generated indicator to at least one reference indicator of the plurality of reference indicators associated with the reference magnetic field; and

determine whether the door is in the closed position based on the comparison of the at least one generated indicator to the at least one reference indicator of the plurality of reference indicators.

11. The door position sensing system of claim 10, wherein the magnetized source device comprises a magnet.

12. The door position sensing system of claim 10, wherein the magnetized source device is positioned within the door frame.

13. The door position sensing system of claim 10, wherein the magnetic field sensor comprises a magnetometer.

14. The door position sensing system of claim 10, wherein the latch mechanism comprises a deadbolt.

15. The door position sensing system of claim 10, wherein the magnetic source device is secured into position by at least one mechanical fastener.

16. The door position sensing system of claim 10, wherein the magnetic field sensor is completely contained within the housing.