Method and system for locating and monitoring first responders

• US 8,706,414 B2
• Filed: 09/14/2012
• Issued: 04/22/2014
• Est. Priority Date: 05/31/2006
• Status: Active Grant

• Current Assignee: TRX Systems, Inc.
• Original Assignee: TRX Systems, Inc.
• Inventors: Funk, Benjamin E., Bandyopadhyay, Amrit, Kohn, Eric A., Goldsman, Neil, Teolis, Carole A., Blankeship, Gilmer L.
• Primary Examiner(s): Shafi, Muhammad
• Application Number:
  US13/616,323
• Publication Number:
  US 20130166198A1
• Time in Patent Office: 585 Days
• Field of Search: 701400-541, 340/539.13, 340/568.1, 340/573.1, 345/633, 345/156
• US Class Current: 701/495
• CPC Class Codes: G01C 21/1654 with electromagnetic compass
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G08B 25/016 Personal emergency signalling and security systems emergency non-personal manually actuated alarm activators G08B25/12
• CPC Class Codes: G08G 1/20 Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles

Abstract

The invention is directed to methods and systems for locating and monitoring the status of people and moveable assets, such as first responders, including firefighters and other public service personnel, and their equipment both indoors and out. The invention provides for locating and monitoring the status of people and assets in environments where GPS systems do not operate, or where operation is impaired or otherwise limited. The system and method uses inertial navigation to determine the location, motion and orientation of the personnel or assets and communicates with an external monitoring station to receive requests for location, motion orientation and status information and to transmit the location, motion orientation and status information to the monitoring station.

Claims

1. A computer-implemented method of reducing errors in inertial tracking data, the method being implemented by a computer that includes a physical processor, the method comprising:

obtaining, as input, tracking data for a trackee at a location, wherein the tracking data includes a collection of position estimates generated based on data obtained from inertial sensors including at least one accelerometer, at least one gyroscope, and at least one magnetic field sensor, and wherein each position estimate includes at least three-dimensional location coordinates;

calculating a path from the tracking data that tracks the trackee;

developing one or more location-related sensor profiles from the tracking data;

inferring one or more building features from the tracking data;

correcting one or more of the position estimates based on the one or more location-related sensor profiles and the one or more building features to reduce tracking errors associated with the inertial sensors;

recalculating the path based on the one or more corrected position estimates; and

causing the one or more corrected position estimates to be displayed via a graphical user interface associated with the computer.

2. The method of claim 1, wherein the trackee comprises a mobile person or mobile asset.

3. The method of claim 1, wherein the one or more building feature are inferred based on the one or more position estimates.

4. The method of claim 1, wherein the one or more building feature include a known building feature on an image of a floor plan displayed via the graphical user interface.

5. The method of claim 1, further comprising:

determining that the trackee is moving in a corridor when a number of steps taken by the trackee, as determined from data obtained from the at least one accelerometer, exceeds a threshold value, and when a gyroscope angle obtained from the at least one gyroscope has not exceeded a threshold value.

6. The method of claim 5, wherein the one or more building features includes the corridor.

7. The method of claim 1, further comprising:

determining that the trackee is moving in a possible stairwell based on detection of an elevation change comprising incrementing or decrementing “

z”

position values as determined from data obtained from the at least one accelerometer, wherein each “

z”

position value change corresponds to a stair encountered by the trackee.

8. The method of claim 7, wherein the one or more building features includes the possible stairwell.

9. The method of claim 7, further comprising:

determining that the trackee has started moving in the possible stairwell based on a change in the “

z”

position value; and

determining that movement in the possible stairwell has ended when the change in the “

z”

position value is zero over a threshold period.

10. The method of claim 7, further comprising:

ignoring a total change in “

z”

position over the possible stairwell if the number of stairs encountered is less than a threshold.

11. The method of claim 7, further comprising:

resolving elevation change data into floor numbers of a building by comparing the number of stairs counted to an expected number of stairs between floors in the building.

12. The method of claim 7, further comprising:

recording the winding of the possible stairwell, the winding being either clockwise, counter clockwise, or straight.

13. The method of claim 1, further comprising:

determining different types of movement of the trackee, utilizing a neural network as a pattern recognition tool, based on data obtained from one or more of the at least one accelerometer, the at least one gyroscope, or the at least one magnetic field sensor.

14. The method of claim 13, further comprising:

obtaining, by the neural network, input comprising training data obtained when the trackee has moved on the path including level ground, up stairs, and down stairs.

15. The method of claim 13, further comprising:

classifying, by the neural network, each individual step taken by the trackee as either being on level ground, up a stair, or down a stair.

16. The method of claim 15, further comprising:

classifying, by the neural network, each individual step based on a shape of a signal obtained from the at least one accelerometer for each individual step.

17. The method of claim 16, further comprising:

measuring the shape of the signal between two consecutive heel strikes.

18. The method of claim 15, further comprising:

obtaining a stair count of each individual step taken by the trackee if the step is up a stair or down a stair.

20. The method of claim 1, wherein the at least one magnetic field sensor measures a magnetic field as a function of position, and wherein the location-related sensor data profile is a magnetic sensor data profile comprising a specific magnetic field distribution associated with a specific location.

21. The method of claim 20, wherein the specific location is an indoor location.

22. The method of claim 20, wherein the magnetic sensor data profile is one of a plurality of magnetic sensor data profiles stored in a database.

19. A non-transitory computer-readable storage medium comprising executable code for reducing errors in inertial tracking data, the computer executable code, when executed by one or more processors, causing the one or more processors to:

obtain, as input, tracking data for a trackee at a location, wherein the tracking data includes a collection of position estimates generated based on data obtained from inertial sensors including at least one accelerometer, at least one gyroscope, and at least one magnetic field sensor, and wherein each position estimate includes at least three-dimensional location coordinates;

calculate a path from the tracking data that tracks the trackee;

develop one or more location-related sensor profiles from the tracking data;

infer one or more building features from the tracking data;

correct one or more of the position estimates based on the one or more location-related sensor profiles and the one or more building features to reduce tracking errors associated with the inertial sensors;

recalculate the path based on the one or more corrected position estimates; and

cause the one or more corrected position estimates to be displayed via a graphical user interface associated with the computer.