Motion detector with accelerometer and false tampering detection

Patent metadata

Field	Value
Publication number	US-12163974-B2
Application number	US-202217585367-A
Country	US
Kind code	B2
Filing date	Jan 26, 2022
Priority date	Jan 26, 2022
Publication date	Dec 10, 2024
Grant date	Dec 10, 2024

Abstract

A system for tamper detection of a motion detector. The system includes an electronic controller configured to receive orientation data from an accelerometer of the motion detector. The electronic controller is also configured to filter the orientation data of the accelerometer of the motion detector. The electronic controller is further configured to determine an orientation of the motion detector using the filtered orientation data. The electronic controller is also configured to identify a tamper condition of the motion detector based on the orientation of the motion detector. The electronic controller is further configured to activate an alarm device of the motion detector based on the tamper condition.

First claim

What is claimed is:

1. A system for tamper detection of a motion detector, the system comprising:
an electronic controller configured to
receive orientation data from an accelerometer of the motion detector;
filter the orientation data of the accelerometer of the motion detector;
determine an orientation of the motion detector using the filtered orientation data;
determine a reference position of the motion detector using the filtered orientation data, wherein the reference position corresponds to an initial position of the motion detector;
determine a drift of the reference position for the motion detector based on the filtered orientation data, wherein the drift is a change in the reference position for the motion detector over time;
calibrate the reference position for the motion detector based on the drift;
identify a force acting on the motion detector causing a change in the orientation of the motion detector based on the calibrated reference position and a current position of the motion detector;
identify a tamper condition of the motion detector based on the change in the orientation of the motion detector from the calibrated reference position and a deviation threshold; and
activate an alarm device of the motion detector based on the tamper condition.

2. The system of claim 1 , wherein the electronic controller is further configured to:
determine that the change in the orientation of the motion detector occurs for greater than a defined time-period.

3. The system of claim 2 , wherein the electronic controller is further configured to:
modify a set of reference points for the reference position of the orientation of the motion detector based on a result of the change in the orientation being greater than or less than a historical set of reference points.

4. The system of claim 1 , wherein identifying the tamper condition of the motion detector, further comprises:
determine that the change in the orientation of the motion detector is greater than the deviation threshold, wherein the change in the orientation of the motion detector corresponds to an external event that impacts the orientation data of the motion detector.

5. The system of claim 4 , wherein the electronic controller is further configured to:
determine that the change in the orientation of the motion detector is less than the deviation threshold for a defined time-period.

6. The system of claim 5 , wherein the electronic controller is further configured to:
deactivate the alarm device of the motion detector based on the change in the orientation of the motion detector and the defined time-period.

7. A method for tamper detection of a motion detector, the method comprising:
receiving, via an electronic controller, orientation data from an accelerometer of the motion detector;
filtering, via the electronic controller, the orientation data of the accelerometer of the motion detector;
determining, via the electronic controller, an orientation of the motion detector using the filtered orientation data;
determining, via the electronic controller, a reference position of the motion detector using the filtered orientation data, wherein the reference position corresponds to an initial position of the motion detector;
determining, via the electronic controller, a drift of the reference position for the motion detector based on the filtered orientation data, wherein the drift is a change in the reference position for the motion detector over time;
calibrating, via the electronic controller, the reference position for the motion detector based on the drift;
identifying, via the electronic controller, a force acting on the motion detector causing a change in the orientation of the motion detector based on the calibrated reference position and a current position of the motion detector;
identifying, via the electronic controller, a tamper condition of the motion detector based on the change in the orientation of the motion detector from the calibrated reference position and a deviation threshold; and
activating, via the electronic controller, an alarm device of the motion detector based on the tamper condition.

8. The method of claim 7 , further comprising:
determining, via the electronic controller, that the change in the orientation of the motion detector occurs for greater than a defined time-period.

9. The method of claim 8 , further comprising:
modifying, via the electronic controller, a set of reference points for the reference position of the orientation of the motion detector based on a result of the change in the orientation being greater than or less than a historical set of reference points.

10. The method of claim 7 , wherein identifying the tamper condition of the motion detector, further comprises:
determining, via the electronic controller, that the change in the orientation of the motion detector is greater than the deviation threshold, wherein the change in the orientation of the motion detector corresponds to an external event that impacts the orientation data of the motion detector.

11. The method of claim 10 , further comprising:
determining, via the electronic controller, that the change in the orientation of the motion detector is less than the deviation threshold for a defined time-period.

12. The method of claim 10 , further comprising:
deactivate the alarm device of the motion detector based on the change in the orientation of the motion detector and a defined time-period.

13. A motion detector comprising:
an alarm device;
an electronic controller;
at least one sensor, wherein the at least one sensor provides an indication of motion to the electronic controller;
an accelerometer, wherein the accelerometer provides orientation data of the motion detector to the electronic controller;
wherein the electronic controller is configured to filter the orientation data of the accelerometer;
wherein the electronic controller is configured to determine an orientation of the motion detector using the filtered orientation data;
wherein the electronic controller is configured to determine a reference position of the motion detector using the filtered orientation data, wherein the reference position corresponds to an initial position of the motion detector;
wherein the electronic controller is configured to determine a drift of the reference position for the motion detector based on the filtered orientation data, wherein the drift is a change in the reference position for the motion detector over time;
wherein the electronic controller is configured to calibrate the reference position for the motion detector based on the drift;
wherein the electronic controller is configured to identify a force acting on the motion detector causing a change in the orientation of the motion detector based on the calibrated reference position and a current position of the motion detector;
wherein the electronic controller is configured to identify a tamper condition of the motion detector based on the change in the orientation of the motion detector from the calibrated reference position and a deviation threshold; and
wherein the electronic controller is configured to activate the alarm device based on the tamper condition.

14. The motion detector of claim 13 , wherein the electronic controller is further configured to determine that the change in the orientation occurs for greater than a defined time-period.

15. The motion detector of claim 14 , wherein the electronic controller is further configured to modify a set of reference points for the reference position of the orientation of the motion detector ba

Assignees

• Bosch Gmbh Robert

Inventors

• Bennis Othmane

Classifications

• G08B29/24

  Self-calibration, e.g. compensating for environmental drift or ageing of components · CPC title

• G08B29/046 Primary

  prevention of tampering with detection circuits · CPC title

• G01P15/00 Primary

  Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration · CPC title

• G01P1/06

  Indicating or recording devices, e.g. for remote indication (indicating or recording in general G01D; registering or indicating working conditions of vehicles G07C5/00) · CPC title

• G01P13/02

  Indicating direction only, e.g. by weather vane · CPC title