Systems and methods for determining a location of an object

• US 7,321,305 B2
• Filed: 07/05/2005
• Issued: 01/22/2008
• Est. Priority Date: 07/05/2005
• Status: Active Grant

• Current Assignee: PINC Solutions Incorporated
• Original Assignee: PINC Solutions Incorporated
• Inventors: Göllü, Aleks
• Primary Examiner(s): Lieu; Julie Bichngoc
• Application Number:
  US11/175,081
• Publication Number:
  US 20070018811A1
• Time in Patent Office: 931 Days
• Field of Search: None
• US Class Current: 340/572.1
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders

Abstract

A system for determining a location of an object. The system includes an object location tracker and a computer system. The object location tracker is configured for attachment to a mobile vehicle and includes an object identification reading device and a position-tracking device. The object identification reading device senses object identification indicia on the object, such as RF ID tags, bar codes, etc., as the mobile vehicle moves around an environment in which the object is situated. The position-tracking device computes the location of the object location tracker as the mobile vehicle moves throughout environment. The computer system associates the sensed object identification indicia of the object, as determined by the reading device, with a location in the environment based on the position of the object location tracker in the environment, as determined by the position-tracking device, when the reading device senses the object identification indicia. The mobile vehicle may include its own mobility system, such as a forklift or an autonomous robotic device, or the mobile vehicle may be, for example, a pushcart that is pushed around the environment.

Claims

1. A system for determining a location of an object, the system comprising:

an object location tracker for attachment to a mobile vehicle, the object location tracker comprising;

an object identification reading device for sensing object identification indicia on the object; and

a position-tracking device for determining a location of the object location tracker as the mobile vehicle moves throughout an environment; and

a computer system in communication with the object location tracker for associating the sensed object identification indicia of the object with a location in the environment based on the position of the object location tracker in the environment as determined by the position-tracking device when the object identification reading device senses the object identification indicia,

wherein the position-tracking device of the object location tracker comprises;

an inertial sensor assembly;

a reference position receiver; and

a high resolution module in communication with the inertial sensor assembly and the reference position receiver, wherein the high resolution module is for computing the location of the object location tracker in real-time based on a combination of input from the inertial sensor assembly and a reference position signal received by the reference position receiver when the object location tracker is located in a first area requiring high position resolution, wherein the high resolution module is for computing the location of the object by;

detecting a current mode of movement for the object location tracker based on the input from the inertial sensor assembly and historical information about the location of the object location tracker;

determining a first estimated position of the object location tracker based at least on a motion model for the current mode of movement for the object location tracker;

determining a second estimated position of mobile object based on the input from the inertial sensor assembly and the historical information about the location of the object location tracker; and

estimating a real-time location of the object location tracker based on the first and second estimated positions.

2. The system of claim 1, wherein the object identification reading device includes a radio frequency identification reader for sensing a radio frequency identification tag on the object.

3. The system of claim 1, wherein the object identification reading device includes a bar code scanner for reading a bar code on the object.

4. The system of claim 1, wherein the object identification reading device includes a camera for recognizing a character on the object.

5. The system of claim 1, wherein the position-tracking device further comprises a global positioning system receiver.

6. The position tracking device of claim 1, wherein the high resolution module is for estimating the real-time location of the mobile vehicle based on the first and second estimated positions using a Kalman filter.

7. The system of claim 6, wherein the high resolution module is further for correcting the historical information about the location of the mobile vehicle based on corrective information.

8. The system of claim 7, wherein the corrective information includes the reference position signal.

9. The system of claim 8, wherein the corrective information includes detection of a transition in the mode of movement by the mobile vehicle.

10. The system of claim 1, wherein the high resolution module is for computing the location of the mobile vehicle by computing a time trajectory between two reference position locations.

11. The system of claim 1, wherein the position-tracking device further comprises a wide area resolution module for computing the position of the mobile vehicle when the mobile vehicle is located in an area requiring lesser position resolution.

12. The system of claim 1, wherein the object location tracker comprises a plurality of object identification reading devices.

13. The system of claim 1, further comprising a plurality of object location trackers, each object location tracker including an object identification reading device and a position-tracking device, and wherein the computer system is for communicating with each of the object location trackers and refines the location of the object based on the received data from the plurality of object location trackers.

14. A system for determining a location of an object, the system comprising:

a vehicle;

an object location tracker attached to the vehicle, the object location tracker comprising;

an object identification reading device for sensing object identification indicia on the object; and

a position-tracking device for determining a location of the object location tracker as the vehicle moves throughout an environment; and

a computer system in communication with the object location tracker for associating the sensed object identification indicia of the object with a location in the environment based on the position of the object location tracker in the environment as determined by the position-tracking device when the object identification reading device senses the object identification indicia,

wherein the position-tracking device of the object location tracker comprises;

an inertial sensor assembly;

a reference position receiver; and

a high resolution module in communication with the inertial sensor assembly and the reference position receiver, wherein the high resolution module is for computing the location of the object location tracker in real-time based on a combination of input from the inertial sensor assembly and a reference position signal received by the reference position receiver when the object location tracker is located in a first area requiring high position resolution, wherein the high resolution module is for computing the location of the object by;

detecting a current mode of movement for the object location tracker based on the input from the inertial sensor assembly and historical information about the location of the object location tracker;

determining a first estimated position of the object location tracker based at least on a motion model for the current mode of movement for the object location tracker;

determining a second estimated position of mobile object based on the input from the inertial sensor assembly and the historical information about the location of the object location tracker; and

estimating a real-time location of the object location tracker based on the first and second estimated positions.

15. The system of claim 14, wherein the vehicle comprises a cart.

16. The system of claim 14, wherein the vehicle comprises a motorized vehicle.

17. The system of claim 14, wherein the vehicle comprises a person.

18. A method for determining a location of an object, the method comprising:

sensing object identification indicia on the object from a mobile vehicle as the mobile vehicle moves in an environment in which the object is located;

detecting the position of the mobile vehicle in the environment by;

detecting movement of the mobile vehicle with an inertial sensor assembly;

determining a current mode of movement of the vehicle based on the detected movement and state estimates for the vehicle for prior instances in time;

determining a first state estimate of the vehicle based at least on a motion model for the current mode of movement of the vehicle;

determining a second state estimate of the vehicle by dead reckoning based on movement of the vehicle detected by the inertial sensor assembly and the state estimates for the vehicle for the prior instances in time; and

determining a near real-time state estimate for the vehicle based on the first and second state estimates; and

associating the sensed object identification indicia of the object with a location in the environment based on the state estimate of the vehicle when the object identification indicia of the object is sensed.

19. The method of claim 18, wherein sensing object identification indicia includes sensing a radio frequency identification tag on the object.

20. The method of claim 18, wherein identifying the object includes reading a bar code on the object.

21. The method of claim 18, wherein identifying the object includes reading a character on the object.

22. The method of claim 18, further comprising generating a representation of the environment including an indication of the location of the object in the environment.

23. The method of claim 18, further comprising computing a time trajectory between two reference position locations.