System and methods for determining the location dynamics of a portable computing device

• US 20050258957A1
• Filed: 07/25/2005
• Published: 11/24/2005
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Horvitz, Eric J., Krumm, John C.
• Granted Patent: US 7,532,113 B2
• Time in Patent Office: Days
• US Class Current: 340/539.130
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 5/02524 Creating or updating the radio-map
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y10S 707/99937 Sorting

Abstract

A location system for locating and determining the motion and velocity of a wireless device. The methods include direct inferences about whether a device is in motion versus static based on a statistical analysis of the variation of radio signal strengths over time. The system is trained according to a sparse set of identified locations from which signal strengths are measured. The system uses the signal properties of the identified locations to interpolate for a new location of the wireless device. The system uses a probabilistic graph where the identified locations of the floor plan, expected walking speeds of pedestrians, and independent inference of whether or not the device is in motion are used to determine the new location of the device.

Claims

1. A graphical user interface that facilitates inferring motion and locating a wireless device, the interface comprising:

an input component for receiving management information, the management information associated with at least the processes of measuring signal strength data of identified locations and generating probability data of the identified locations to further determine a new location of the wireless device; and

a presentation component for presenting a representation of the identified locations to facilitate user interaction therewith.

2. The interface of claim 1, the management information including mapping information that maps a discrete low-density node with each of the identified locations.

3. The interface of claim 1, the management information including mapping information received from a mapping component that maps a discrete low-density node to each of the identified locations, and distributes high-density nodes among the low-density nodes according to predetermined spatial criteria, the mapping information presented by the presentation component.

4. The interface of claim 1, further comprising a mapping feature that maps a discrete low-density node with each of the identified locations, and determines corresponding distances between the low-density nodes.

5. The interface of claim 1, the presentation component providing a graphical representation of possible paths that the wireless device may traverse to the identified locations.

6. The interface of claim 1, further comprising a plotting feature for providing a graphical representation of all of the identified locations to which the wireless device may travel, and possible paths that the wireless device may traverse to the identified locations.

7. The interface of claim 1, further comprising a plotting feature for providing the capability of assigning edge weights to adjacent and non-adjacent nodes.

8. The interface of claim 1, further comprising a plotting feature for representing pathways to the identified locations and automatically converting the endpoint of each pathway to an end node, which is one type of location node.

9. The interface of claim 1, further comprising a plotting feature for automatically distributing intermediate nodes among the location nodes according to predetermined spatial criteria.

10. The interface of claim 1, further comprising a floor layout of individual location representations of the identified locations, wherein the location representations are selectable.

11. The interface of claim 1, further comprising a plotting feature for plotting the signal properties associated with the selected identified location and an unselected location.

12. The interface of claim 1, the user input component comprising at least one of:

means for selecting a building associated with the locations;

means for selecting a floor in the building;

means for selecting one of the locations; and

means for selecting a scan rate for sampling the signal properties.

13. The interface of claim 1, further comprising graphical means to display a color and/or a pattern corresponding to user preference information.