Sensor network system, sensor node, sensor information collector, method of observing event, and program thereof

• US 7,652,565 B2
• Filed: 09/15/2006
• Issued: 01/26/2010
• Est. Priority Date: 09/16/2005
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Takaoka, Masanori, Nakao, Toshiyasu
• Primary Examiner(s): Crosland; Donnie L
• Application Number:
  US11/532,174
• Publication Number:
  US 20070067742A1
• Time in Patent Office: 1,229 Days
• Field of Search: 340/506, 340/525
• US Class Current: 340/506
• CPC Class Codes: G01D 1/00 Measuring arrangements giving results other than momentary value of variable, of general application G01D3/00 takes precedence; in tariff metering apparatus G01D4/00; transducers not specially adapted for a specific variable G01D5/00
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: G01K 1/026 arrangements for monitoring a plurality of temperatures, e.g. by multiplexing
• CPC Class Codes: G01K 2213/00 Temperature mapping
• CPC Class Codes: G01K 7/42 Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/0882 Utilisation of link capacity
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/11 Identifying congestion

Abstract

In a sensor network system, sensor data having a high precision (high resolution) is collected, and congestion of a communication network and an apparatus for processing the sensor data is suppressed. A sensor node has a contribution degree calculator for calculating an influence that the detected sensor information exerts upon the entire system precision (resolution). A first communicating circuit transmits sensor information responding to a calculated contribution so that no congestion caused by transmitting too large a quantity of data all at once occurs.

Claims

1. A sensor network system, comprising:

a plurality of sensor nodes each including a sensor for detecting an event that has occurred, and a communicating facility configured to transmit sensor information indicating the event detected by said sensor at a timing corresponding to an influence that the event detected by said sensor exerts upon a sensor information distribution indicating a temporal distribution and a spatial distribution of said event; and

an application apparatus for employing said sensor information distribution, thereby to process said sensor information.

2. The sensor network system according to claim 1, wherein the communicating facility of the sensor node more preferentially transmits the sensor information of which an influence is larger, said influence being exerted by the event detected by the sensor upon the sensor information distribution.

3. The sensor network system according to claim 1, wherein the sensor node having an event model, said event model obtained by making a modeling of the event that the sensor detects, includes a contribution degree calculator for, based upon said event model, calculating a contribution degree, being a degree at which an influence is exerted upon the sensor information distribution, and

wherein the communication facility transmits the sensor information at a timing corresponding to the contribution degree calculated by said contribution degree calculator.

4. The sensor network system according to claim 3, wherein the contribution degree calculator of the sensor node calculates the contribution degree based upon the event that the sensor has detected currently, the event that the sensor detected in the past, and the event model.

5. The sensor network system according to claim 3, wherein the contribution degree calculator of the sensor node calculates the contribution degree based upon the event that the sensor has detected currently, the event that the sensor of the other sensor node has detected, and the event model.

6. The sensor network system according to claim 3, wherein the sensor node includes a model updating means for changing the event model set in the contribution degree calculator.

7. The sensor network system according to claim 1, comprising a server for receiving the sensor information from the sensor node, wherein said server includes a data collecting means for generating a sensor information distribution based upon the received sensor information.

8. The sensor network system according to claim 7, wherein the server includes an estimating means for, based upon the sensor information received from the other sensor node, or the sensor information that temporally or spatially neighbors sensor information that is deficient, and the set event model, estimating said sensor information that is deficient, thereby to restore the sensor information distribution.

9. The sensor network system according to claim 6, comprising a server for receiving the sensor information from the sensor node, wherein said server includes:

a data collecting means for generating a sensor information distribution based upon the received sensor information; and

a model deciding means for deciding the event model that the model updating means of the sensor node updates, based upon said sensor information distribution, and

wherein said model updating means of said sensor node changes the event model set in the contribution degree calculating means into the event model decided by said model deciding means.

10. The sensor network system according to claim 9, wherein the server includes an estimating means for, based upon the sensor information received from the other sensor node, or the sensor information that temporally or spatially neighbors sensor information that is deficient, and the set event model, estimating said sensor information that is deficient, thereby to restore the sensor information distribution,

wherein the model deciding means decides an event model that is set in said estimating means, based upon said sensor information distribution, and

wherein said server farther includes a model setting means for setting the event model decided by said model deciding means in said estimating means.

11. The sensor network system according to claim 7, wherein the server includes a sensor information distribution transmitting means for transmitting the sensor information distribution to an application apparatus.

12. The sensor network system according to claim 1, wherein the application apparatus includes a data collecting means for receiving sensor information from the sensor node, thereby to generate a sensor information distribution based upon the received sensor information.

13. The sensor network system according to claim 12, wherein the application apparatus includes an estimating means for, based upon the sensor information received from the other sensor node, or the sensor information that temporally or spatially neighbors sensor information that is deficient, and the set event model, estimating said sensor information that is deficient, thereby to restore the sensor information distribution.

14. A sensor node, comprising:

a sensor for detecting an event; and

a communicating means for transmitting sensor information indicating the event detected by said sensor at a timing directly related to an influence that the event detected by said sensor exerts upon a sensor information distribution indicating a temporal distribution or a spatial distribution of the event.

15. The sensor node according to claim 14, including an event model, said event model obtained by modeling of the event that the sensor detects, and comprising a contribution degree calculator for, based upon said event model, calculating a contribution degree, being a degree at which an influence is exerted upon the sensor information contribution.

16. The sensor node according claim 15, wherein the contribution degree calculator calculates the contribution degree based upon the event that the sensor has detected currently, the event that the sensor detected in the past, and the event model.

17. The sensor node according claim 15, wherein the contribution degree calculator calculates the contribution degree based upon the event that the sensor has detected currently, the event that the sensor of the other sensor node has detected, and the event model.

18. The sensor node according claim 15, comprising a model updating means for changing the event model in the contribution degree calculator.

19. A sensor information collector that is connected to a plurality of sensor nodes each comprising a sensor for detecting an event that has occurred, and receives sensor information indicating the event detected by said sensor, comprising:

a receiving means for receiving the sensor information; and

a data collecting means for, based upon said received sensor information, generating a sensor information distribution indicating a temporal distribution or a spatial distribution of the event;

and further comprising;

an estimating means for estimating, based upon the sensor information received from the other sensor node, or the sensor information that temporally or spatially neighbors sensor information that is deficient, and an event model that has been set, said event model obtained by making a modeling of the event that the sensor detects, said sensor information that is deficient, thereby to restore the sensor information distribution.

20. The sensor information collector according to claim 19, comprising:

a model deciding means for, based upon the sensor information distribution, deciding an event model that is set in the estimating means, said event model obtained by modeling of the event that the sensor detects; and

a model setting means for setting the event model decided by said model deciding means in said estimating means.

21. An event observation method employing a sensor network system comprising a plurality of sensor nodes each including a sensor for detecting an event that has occurred, and an application apparatus for processing sensor information indicating the event detected by said sensor, the method comprising:

an event detection step in which said sensor detects the event;

a sensor information transmission step in which a communicating means of said sensor node transmits the sensor information at a timing corresponding to an influence that the event detected by said sensor in said event detection step exerts upon a sensor information distribution indicating a temporal distribution or a spatial distribution of said event; and

a sensor information process step in which said application apparatus employs the sensor information distribution, thereby to process the sensor information.

22. The event observation method according to claim 21, wherein the communicating means of the sensor node more preferentially transmits the sensor information of which an influence is larger, said influence being exerted by the event detected by the sensor upon the sensor information distribution in the sensor information transmission step.

23. The event observation method according to claim 21, comprising a contribution degree calculation step in which a contribution degree calculating means of the sensor node having an event model set calculates a contribution degree, being a degree at which an influence is exerted upon the sensor information distribution, said event model obtained by making a modeling of the event that the sensor detects, based upon said event model.

24. The event observation method according to claim 23, wherein the contribution degree calculating means of the sensor node calculates the contribution degree, based upon the event that the sensor has detected currently, the event that the sensor detected in the past, and the event model in the contribution degree calculation step.

25. The event observation method according to claim 23, wherein the contribution degree calculating means of the sensor node calculates the contribution degree based upon the event that the sensor has detected currently, the event that the sensor of the other sensor node has detected, and the event model in the contribution degree calculation step.

26. The event observation method according to claim 23, comprising a model update step in which a model update means of the sensor node changes the event model set in the contribution degree calculating means for setting.

27. The event observation method according to claim 21, comprising a data collection step in which a data collecting means of a server of the sensor network system generates the sensor information distribution based upon the received sensor information.

28. The event observation method according to claim 27, comprising an estimation step in which, based upon the sensor information received from the other sensor node, or the sensor information that temporally or spatially neighbors sensor information that is deficient, and the set event model, an estimating means of the server estimates said sensor information that is deficient, thereby to restore the sensor information distribution.

29. The event observation method according to claim 26, comprising:

a data collection step in which the data collecting means of the server of the sensor network system generates a sensor information distribution based upon the received sensor information; and

a model decision step in which a model deciding means decides the event model that the model updating means of the sensor node updates, based upon said sensor information distribution, wherein said model updating means of said sensor node changes the event model set in the contribution degree calculating means into the event model decided in said model decision step by said model deciding means of said sensor node in a model update step.

30. The event observation method according to claim 29, comprising an estimation step in which, based upon the sensor information received from the other sensor node, or the sensor information that temporally or spatially neighbors sensor information that is deficient, and the set event model, an estimating means of the server estimates said sensor information that is deficient, thereby to restore the sensor information distribution,

wherein the model deciding means decides the event model that is set in said estimating means, based upon the sensor information distribution in a model decision step, and

further comprising a model setting step in which a model setting means of said server sets the event model decided by said model deciding means in said estimating means.

31. The event observation method according to claim 27, comprising a sensor information distribution transmission step in which a sensor information distribution transmitting means of the server transmits the sensor information distribution to the application apparatus.

32. The event observation method according to claim 21, comprising a data collection step in which a data collecting means of the application apparatus receives the sensor information from the sensor node to generate the sensor information distribution based upon the received sensor information.

33. The event observation method according to claim 32, comprising an estimation step in which, based upon the sensor information received from the other sensor node, or the sensor information that temporally or spatially neighbors sensor information that is deficient, and the set event model, an estimating means of the application apparatus estimates said sensor information that is deficient, thereby to restore the sensor information distribution.

34. A record medium having a program stored therein, said record medium being a computer-readable record medium, wherein said program is a sensor node program incorporated in and operable to cause a computer to perform a process of, in transmitting sensor information indicating an event detected by a sensor, more preferentially transmitting the sensor information that exerts a larger influence upon a sensor information distribution indicating a temporal distribution or a spatial distribution of the event.

35. A record medium having a program stored therein, said record medium being a computer-readable record medium, wherein said program is a sensor information collection program that is installed in a computer that is connected to a plurality of sensor nodes each comprising a sensor for detecting an event that has occurred, and receives sensor information indicating the event detected by said sensor, said sensor information collection program causing said computer to perform a data collection process of, based upon the received sensor information, generating a sensor information distribution indicating a temporal distribution or a spatial distribution of the event.