Multi-mode navigation device and method

• US 20040059502A1
• Filed: 09/17/2003
• Published: 03/25/2004
• Est. Priority Date: 09/20/2002
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Davis, Steven J., Levi, Robert W., Judd, Charles T.
• Granted Patent: US 7,103,471 B2
• Time in Patent Office: Days
• US Class Current: 701/224
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: G01C 21/12 executed aboard the object being navigated; Dead reckoning
• CPC Class Codes: G01C 22/006 Pedometers

Abstract

A method and apparatus for providing dead reckoning position data, orientation, and heading of a person is disclosed. The apparatus uses an algorithm that automatically determines the appropriate set of navigation functions for personal navigation based upon the orientation of the apparatus. Dead reckoning is accomplished by combining electronic heading and motion signals from human ambulation. Individual orientation and human motion measurement is accomplished with motion sensing devices. In one implementation of the invention, a navigation device provides different heading, position, and/or orientation functionality depending on whether the navigation device is affixed to the user in a vertical position or horizontal position, or the navigation device is not affixed to the user.

Claims

1. A navigation device comprising:

an electronic compass to detect an orientation and provide a corresponding heading signal;

one or more motion sensing devices to detect motion along different axis and provide corresponding motion signals; and

a processing unit communicatively coupled to the electronic compass and one or more motion sensing devices to received the heading signal and one or more motion signals, determine a position and orientation, and automatically provide different navigation information depending on the orientation of the navigation device.

2. The navigation device of claim 1 wherein the processing unit is further configured to provide different navigation information depending on whether the navigation device is affixed to a user or not.

3. The navigation device of claim 2 further comprising:

a visible indicator to provide navigation information to a user; and

a holster to affix the navigation device to a user..

4. The navigation device of claim 1 wherein the navigation device automatically switches between different modes of operation depending on the orientation of the navigation device,

and provide either heading or position information, depending on the mode of operation.

5. The navigation device of claim 1 wherein

if the navigation device is affixed to a user and the device is in a primary orientation, navigation calculations are made according to bipedal ambulation to provide a position,

if the navigation device is affixed to a user and the device is in a secondary orientation, then navigation calculations are made according to crawling ambulation to provide a position, and

if the navigation device is hand-held, only azimuth data is provided to the user.

6. The navigation device of claim 1 further comprising:

a communication port to transmit navigation information.

7. A method of navigation comprising:

determining whether a navigation device is affixed to a user;

obtaining an azimuth heading;

calculating a dead reckoning position if the navigation device is affixed to the user;

providing azimuth heading and dead reckoning position if the navigation device is affixed to the user; and

providing azimuth heading otherwise.

8. The method of claim 7 further comprising:

determining an orientation of the navigation device relative to a horizontal plane;

calculating the dead reckoning position according to bipedal ambulation when the navigation device is affixed to the user and is in a first orientation; and

calculation the dead reckoning position according to crawling ambulation when the navigation device is affixed to the user and is in a second orientation.

9. A method comprising:

determining the orientation of a navigation device;

automatically selecting a first motion measurement algorithm if the navigation device is in a first orientation;

automatically selecting a second motion measurement algorithm if the navigation device is in a second orientation; and

providing a position according to the pedometry algorithm selected.

10. The method of claim 9 wherein the orientation of the navigation device is determined relative to a horizontal plane.

11. The method of claim 9 further comprising:

determining if the navigation device is affixed to a user;

automatically selecting the first motion measurement algorithm if the navigation device is in the first orientation and affixed to the user;

automatically selecting the second motion measurement algorithm if the navigation device is in the second orientation and affixed to the user; and

suspending all motion measurement calculations if the navigation device is not affixed to the user.

12. A machine-readable medium having one or more instructions for dead reckoning navigation, which when executed by a processor, causes the processor to perform operations comprising

determining whether a navigation device is affixed to a user;

obtaining an azimuth heading;

calculating a dead reckoning position if the navigation device is affixed to the user;

outputting the azimuth heading and dead reckoning position if the navigation device is affixed to the user; and

outputting the azimuth heading otherwise.

13. The machine-readable medium of claim 12 to further:

determining an orientation of the navigation device relative to a horizontal plane,

calculating the dead reckoning position according to bipedal ambulation when the navigation device is affixed to the user and is in a first orientation, and

calculation the dead reckoning position according to crawling ambulation when the navigation device is affixed to the user and is in a second orientation.