METHOD AND SYSTEM FOR POSITIONING OBJECT WITH ADAPTIVE RESOLUTION

• US 20100090899A1
• Filed: 09/25/2009
• Published: 04/15/2010
• Est. Priority Date: 10/09/2008
• Status: Abandoned Application

• Current Assignee: NEC Company Limited
• Original Assignee: NEC Company Limited
• Inventors: ZHAO, Junhui, WANG, Yongcai
• Application Number:
  US12/567,572
• Publication Number:
  US 20100090899A1
• Time in Patent Office: Days
• US Class Current: 342/387
• CPC Class Codes: G01S 5/02525 Gathering the radio frequency fingerprints
• CPC Class Codes: G01S 5/02527 Detecting or resolving anomalies in the radio frequency fingerprints of the radio-map
• CPC Class Codes: G01S 5/0264 at least one of the systems being a non-radio wave positioning system
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: G01S 5/18 using ultrasonic, sonic, or infrasonic waves

Abstract

The present invention provides a method and system for positioning an object with adaptive resolution. The method comprises: dividing a space to be detected into Hot Area and General Area; arranging, according to the positions of Hot Area and General Area, high-resolution positioning signal (US) transceivers and low-resolution positioning signal (RF) transceivers, wherein the detection scope of the low-resolution positioning signal transceivers covers the space and the detection scope of the high-resolution positioning signal transceivers covers the Hot Area; and when the object moving in the space, fusing the detection results from the high-resolution positioning signal transceivers and the low-resolution positioning signal transceivers to determine the position of the object with adaptive resolution. With the system of the present invention, for different areas, the object can be positioned with different positioning resolutions (precisions or granularities). Also, since it is not necessary to use a great deal of high-precision positioning devices, the system cost can be reduced considerably.

Claims

1. A method for positioning object with adaptive resolution, comprising:

dividing a space to be detected into Hot Area and General Area;

arranging, according to the positions of Hot Area and General Area, high-resolution positioning signal transceivers and low-resolution positioning signal transceivers, wherein the detection scope of the low-resolution positioning signal transceivers covers the space and the detection scope of the high-resolution positioning signal transceivers covers the Hot Area; and

when the object moving in the space, fusing the detection results from the high-resolution positioning signal transceivers and the low-resolution positioning signal transceivers to determine the position of the object with adaptive resolution.

2. The method according to claim 1, wherein the object is capable of transmitting the high-resolution positioning signal and the low-resolution positioning signal.

3. The method according to claim 1, further comprising:

generating a radio map as positioning reference when performing low-resolution positioning.

4. The method according to claim 3, wherein the radio map is generated by using a semi-supervised learning method by steps of:

obtaining detection results for low-resolution positioning signals and high-resolution positioning signals from a plurality of positions in the space to be detected;

when a position is located in the Hot Area, labeling the detection results for low-resolution positioning signals from the position with the corresponding detection results for high-resolution positioning signals; and

generating the radio map based on the labeled and unlabeled detection results for low-resolution positioning signals.

5. The method according to claim 3, wherein the step of determining the position of the object comprises:

determining the position of the object according to the detection results of the high-resolution positioning signal transceivers when the object is located in the Hot Area; and

determining the position of the object by searching the radio map with the detection results of the low-resolution positioning signal transceivers when the object is located in the General Area.

6. The method according to claim 3, wherein during the process of determining the position of the object, the radio map is corrected according to high-resolution positioning results.

7. The method according to claim 1, further comprising a Hot Area modification step for adjusting the positions of the high-resolution positioning signal transceivers to make sure that the Hot Area is covered by the detection scope of the high-resolution positioning signal transceivers.

8. The method according to claim 7, wherein the Hot Area modification step comprises:

placing, on the edge of the Hot Area, a plurality of monitoring devices capable of transmitting high-resolution positioning signals;

receiving the high-resolution positioning signals from the monitoring devices by the high-resolution positioning signal transceivers; and

adjusting the positions of the high-resolution positioning signal transceivers according to the received high-resolution positioning signals to make sure that the Hot Area is covered by the detection scope of the high-resolution positioning signal transceivers.

9. The method according to claim 2, wherein the high-resolution positioning signal is ultrasound or sound signal.

10. The method according to claim 2, wherein the low-resolution positioning signal is radio frequency, infrared or Wifi signal.

11. The method according to claim 9, wherein the plurality of high-resolution positioning signal transceivers receive the high-resolution positioning signals from the object to generate a Time-of-Arrival vector, and the step of determining the position of the object comprises:

calculating the position of the object according to the Time-of-Arrival vector if the number of elements included in the Time-of-Arrival vector is more than or equal to 3; and

determining the position of the object by searching the radio map if the number of elements included in the Time-of-Arrival vector is less than 3.

12. The method according to claim 11, wherein when the number of elements included in the Time-of-Arrival vector is more than or equal to 3, a trilateration or multilateration algorithm is used to calculate the position of the object.

13. A system for positioning object with adaptive resolution, comprising:

a tag device carried by the object for transmitting high-resolution positioning signal and low-resolution positioning signal;

a high-resolution positioning apparatus including high-resolution positioning signal transceivers for transmitting and receiving the high-resolution positioning signal;

a low-resolution positioning apparatus including low-resolution positioning signal transceivers for transmitting and receiving the low-resolution positioning signal; and

a results processing device for fusing the detection results from the high-resolution positioning apparatus and the low-resolution positioning apparatus to determine the position of the object with adaptive resolution, wherein the space to be detected is divided into Hot Area and a General Area, the detection scope of the low-resolution positioning apparatus covers the space, and the detection scope of the high-resolution positioning apparatus covers the Hot Area.

14. The system according to claim 13, further comprising:

a radio map generating device for generating a radio map as positioning reference for the low-resolution positioning apparatus.

15. The system according to claim 14, wherein the radio map generating device comprises:

a results obtaining unit for obtaining detection results for the high-resolution positioning signals and the low-resolution positioning signals from a plurality of positions in the space to be detected;

a results labeling unit for labeling, when a position is located in the Hot Area, the detection results for low-resolution positioning signals from the position with the corresponding detection results for high-resolution positioning signals; and

a radio map generation unit for using a semi-supervised learning method to generate the radio map based on the labeled and unlabeled detection results for low-resolution positioning signals.

16. The system according to claim 14, wherein the results processing device carries out operations of:

determining the position of the object according to the detection results of the high-resolution positioning signal transceivers in the high-resolution positioning apparatus when the object is located in the Hot Area; and

determining the position of the object by searching the radio map with the detection results of the low-resolution positioning signal transceivers in the low-resolution positioning apparatus when the object is located in the General Area.

17. The system according to claim 14, further comprising:

a radio map correction device for correcting, during the process of determining the position of the object, the radio map according to the detection results of the high-resolution positioning signal transceivers in the high-resolution positioning apparatus.

18. The system according to claim 13, further comprising:

a Hot Area modification device for adjusting the positions of the high-resolution positioning signal transceivers in the high-resolution positioning apparatus to make sure that the Hot Area is covered by the detection scope of the high-resolution positioning signal transceivers.

19. The system according to claim 13, wherein the high-resolution positioning signal is ultrasound or sound signal.

20. The system according to claim 13, wherein the low-resolution positioning signal is radio frequency, infrared or Wifi signal.

21. The system according to claim 13, wherein the results processing device is located in a location server.