Sensor web

• US 9,385,825 B2
• Filed: 04/11/2011
• Issued: 07/05/2016
• Est. Priority Date: 10/09/2002
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Delin, Kevin A., Jackson, Shannon P.
• Primary Examiner(s): Barbee, Manuel L
• Application Number:
  US13/084,281
• Publication Number:
  US 20110196651A1
• Time in Patent Office: 1,912 Days
• US Class Current: 1/1
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: H04J 3/0641 Change of the master or reference, e.g. take-over or failure of the master
• CPC Class Codes: H04W 40/24 Connectivity information management, e.g. connectivity discovery or connectivity update
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A Sensor Web formed of a number of different sensor pods. Each of the sensor pods include a clock which is synchronized with a master clock so that all of the sensor pods in the Web have a synchronized clock. The synchronization is carried out by first using a coarse synchronization which takes less power, and subsequently carrying out a fine synchronization to make a fine sync of all the pods on the Web. After the synchronization, the pods ping their neighbors to determine which pods are listening and responded, and then only listen during time slots corresponding to those pods which respond.

Claims

1. A method, comprising:

deploying a plurality of sensor pods having a specified hardware characteristic and forming a sensor web;

establishing wireless communications between sensor pods of the plurality of sensor pods that are within a communication range of other sensor pods of the plurality of sensor pods;

activating the sensor pods of said plurality to carry out a specified operation at each of a plurality of spaced locations;

evolving the sensor web by adding more sophisticated sensor pods which have an additional hardware characteristic than said specified hardware characteristic; and

carrying out indirect measurements with at least one sensor pod by processing nonlocal information received from other sensor pods of the plurality of sensor pods.

2. The method as in claim 1, further comprising:

synchronizing said spaced sensor pods such that said spaced sensor pods each include a synchronized clock; and

using said synchronized clock to synchronize said spaced sensor pods to determine a parameter at times that are based on said synchronized clock.

3. The method as in claim 2, wherein said using comprises causing said sensor pods to each determine the parameter at precisely the same time and at said different locations.

4. The method as in claim 2, wherein said synchronizing comprises

first carrying out a coarse synchronization which coarsely synchronizes said sensor pods while minimizing an amount of consumed power,

and second carrying out a fine synchronization which more finely synchronizes said sensor pods.

5. The method as in claim 2, further comprising sharing information among all of said sensor pods such that all of said sensor pods receive information about all of the parameters sensed at each of the spaced locations.

6. The method of claim 5, wherein sharing information is carried out by at least one first sensor pod transmitting the information to at least one second sensor pod through at least one third sensor pod.

7. The method as in claim 2, further comprising a ping routine, during which each of the sensor pods determine which other sensor pods respond to pings and time slots assigned to said other sensor pods, and wherein each sensor pod listens to other sensor pods only during said time slots.

8. The method as in claim 2, further comprising sharing data between the plurality of sensor pods, such that each of the sensor pods receives data from each other sensor pod.

9. The method as in claim 8, further comprising processing the data from the plurality of sensor pods in the sensor pods, to determine information from the data.

10. The method as in claim 9, wherein the information from the data is vector information related to a value of parameters sensed at different locations.

11. The method as in claim 2, further comprising adding another sensor pod to the Sensor Web during operation of the Sensor Web.

12. The method as in claim 11, further comprising, after adding said another sensor pod, synchronizing a clock within said another sensor pod with said synchronized clock.

13. The method as in claim 2, wherein said synchronizing comprises carrying out a first, coarse synchronization at reduced power consumption, and subsequently carrying out a second, fine synchronization, at a higher power consumption.

14. The method as in claim 2, further comprising using said synchronized clock to carry out a main processing loop in each of said plurality of sensor pods which both starts and ends at substantially the same time.

15. The method of claim 1, further comprising sending an event-trigger to each sensor pod of the plurality of sensor pods.

16. The method of claim 15, wherein the event-trigger is a wake-up trigger for dormant sensor pods.

17. The method of claim 15, wherein the event-trigger is for changing a measurement cycle of a sensor pod.

18. The method of claim 1, wherein processing nonlocal information comprises extending a range or sensitivity of a sensor pod by applying spatio-temporal trending.

19. The method of claim 1, wherein processing nonlocal information comprises combining scalar information into vector information.