Motion detection devices and systems

Patent metadata

Field	Value
Publication number	US-10054517-B2
Application number	US-201615242650-A
Country	US
Kind code	B2
Filing date	Aug 22, 2016
Priority date	Jul 29, 2014
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

Motion detection devices and systems are described herein. One motion detection device includes an inertial measurement unit (IMU) configured to measure velocity, orientation, and gravitational forces of the motion detection device and a computing component. The computing component can be configured to determine spectrum parameters of a mobile vehicle associated with the motion detection device using measurements from the IMU, determine IMU orientation parameters using measurements from the IMU, and estimate motion of the mobile vehicle using the spectrum parameters, the IMU orientation parameters, measurements from the IMU, and a motion estimation function.

First claim

The invention claimed is:

1. A motion detection device including:
an inertial measurement unit (IMU) configured to measure velocity, orientation, and gravitational forces of the motion detection device; and
a computing component configured to:
determine spectrum parameters of a mobile vehicle associated with the motion detection device using measurements from the IMU;
determine IMU orientation parameters using measurements from the IMU;
estimate motion of the mobile vehicle using at least one of the spectrum parameters, the IMU orientation parameters, measurements from the IMU, a motion estimation function, and a motion estimation threshold; and
deactivate information conveyed to a user in response to the spectrum parameters of the mobile vehicle being below the cutoff frequency range.

2. The device of claim 1 , wherein the computing component is configured to determine the IMU orientation parameters includes determining a gravity vector to determine a vertical tilting angle.

3. The device of claim 1 , wherein the computing component is configured to filter mobile vehicle vibrations from vibrations induced by actual movement.

4. The device of claim 1 , wherein the computing component is configured to filter the IMU measurements, wherein filtering the IMU measurements includes performing:
gravity correction to distill linear accelerations; and
offset correction to remove systematic sensor reading drifts using a zero resetting parameter.

5. The device of claim 1 , wherein the computing component is configured to perform an exponentially weighted moving average (EWMA) filter process in response to resampling to 100 hertz.

6. The device of claim 1 , wherein the computing component is configured to estimate speed of the mobile vehicle based on a past speed estimate and current IMU measurements.

7. The device of claim 1 , wherein the motion estimation function includes a sliding window Discrete Fourier Transformation function (DFT).

8. The device of claim 1 , including a user interface to provide a display on a screen in response to a determination that the mobile vehicle is not in motion.

9. The device of claim 1 , wherein the IMU orientation parameters include IMU accelerometer readings along X, Y, and Z axes.

10. A method, comprising:
measuring, with an inertial measurement unit, motion of a mobile vehicle while the mobile vehicle is idle;
determining spectrum parameters of the mobile vehicle using the measurements from the inertial measurement unit;
determining time domain filter parameters of the mobile vehicle using the measurements from the inertial measurement unit;
determining motion patterns, with the inertial measurement unit, while the mobile vehicle is moving in a variety of patterns;
characterizing system performance based on the motion patterns; and
determining window parameters using measurements from the inertial measurement unit while the mobile vehicle is moving and a sliding window motion estimation function.

11. The method of claim 10 , comprising comparing a frequency of vibrations while the mobile vehicle is moving to a frequency of vibrations while the mobile vehicle is idle.

12. The method of claim 10 , wherein the spectrum parameters comprise at least one of a cutoff frequency range while the mobile vehicle is idle and a maximum frequency while the mobile vehicle is moving.

13. The method of claim 10 , wherein time domain filter parameters comprise at least one of an exponentially weighted moving average parameters, a parameter for speed estimation, and a zero resetting parameter.

14. The method of claim 10 , wherein determining motion patterns, with the inertial measurement unit, while the mobile vehicle is moving in a variety of patterns comprises motion pattern benchmarking.

15. The method of claim 10 , wherein characterizing system performance based on the motion patterns comprises characterizing system performance based on the motion patterns based on at least one of inertial measurement unit response delays, false positive rates, and false negative rates.

16. The method of claim 10 , wherein determining window parameters comprises applying the sliding window motion estimation function to the measurements from the inertial measurement unit while the mobile vehicle is moving in a variety of patterns.

17. The method of claim 10 , wherein window parameters comprise at least one of a window size, a shift size, and a motion estimation threshold.

18. A method, comprising:
determining a gravity vector from measurements taken by an inertial measurement unit while a mobile vehicle is on a flat surface and the mobile vehicle's engine is off;
determine, using the gravity vector, a vertical tilting angle of a motion detection device;
if the motion detection device is mounted with only one tilting degree of freedom, determining a forward vector using inertial measurement unit orientation parameters; and
if the motion detection device is mounted with more than one tilting degree of freedom:
determining an acceleration peak maximum from measurements taken by the inertial measurement unit while the mobile vehicle is moving;
determining a horizontal tilting angle of the motion detection device using the determined acceleration peak maximum; and
determining a forward vector using inertial measurement unit orientation parameters.

19. The method of claim 18 , wherein determining a gravity vector comprises determining the gravity vector from accelerometer readings of the inertial measurement unit along X, Y, and Z axes.

20. The method of claim 18 , wherein determining an acceleration peak maximum comprises adjusting X, Y, Z values to maximize a highest acceleration peak.

Assignees

• Honeywell Int Inc

Inventors

• Liu Haiyang
• Baker Jeffrey
• Cunningham Iv Charles Joseph
• Caldwell William Stephen

Classifications

• G07C5/02

  Registering or indicating driving, working, idle, or waiting time only (apparatus forming part of taximeters G07B13/00) · CPC title

• G01M17/007 Primary

  Wheeled or endless-tracked vehicles (G01M17/08 takes precedence) · CPC title

• G01P13/00 Primary

  Indicating or recording presence, absence, or direction, of movement (electric switches H01H; counting moving objects G06M7/00) · CPC title

• G01P3/50 Primary

  for measuring linear speed (G01P3/56 takes precedence) · CPC title