Forming a convex polygon of mobile sensors

• US 8,902,792 B2
• Filed: 11/20/2012
• Issued: 12/02/2014
• Est. Priority Date: 10/24/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ferre, Wilfredo, Kanevsky, Dimitri, Sainath, Tara N., Yvon, Marc P.
• Primary Examiner(s): Elliott, IV, Benjamin H
• Assistant Examiner(s): Nowlin, Eric
• Application Number:
  US13/681,771
• Publication Number:
  US 20140114625A1
• Time in Patent Office: 742 Days
• Field of Search: 370/328, 370/252, 370/389, 370/311, 370/338, 370/316, 370/254, 455/456.1, 455/67.13, 455/446, 455/457, 702/150, 702/118, 709/206, 709/224, 709/223
• US Class Current: 370/255
• CPC Class Codes: G06F 17/10 Complex mathematical operations function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544
• CPC Class Codes: G06F 17/11 for solving equations , e.g. nonlinear equations, general mathematical optimization problems optimization specially adapted for a specific administrative, business or logistic context G06Q10/04

Abstract

Forming a convex polygon of a plurality of mobile sensors in an area is provided. Sensor output data received from the plurality of mobile sensors in the area is analyzed using an optimization problem. It is determined whether the plurality of mobile sensors forms the convex polygon in the area. In response to determining that the plurality of mobile sensors does form the convex polygon in the area, an objective function and a set of constraints corresponding to the optimization problem are generated. Then, a sparse solution of the optimization problem is calculated using the objective function and the set of constraints to determine vector weight values for each of the plurality of mobile sensors.

Claims

1. A computer system for forming a convex polygon of a plurality of mobile sensors in a defined area of interest, the computer system comprising:

a bus system;

a storage device connected to the bus system, wherein the storage device stores computer readable program code; and

a processor unit connected to the bus system, wherein the processor unit executes the computer readable program code to;

analyze qualitative sensor output data received from the plurality of mobile sensors in the defined area of interest using an optimization problem;

determine whether the plurality of mobile sensors forms the convex polygon within the defined area of interest;

generate an objective function and a set of constraints corresponding to the optimization problem in response to determining that the plurality of mobile sensors does form the convex polygon within the defined area of interest, wherein the objective function is a difference between a vector associated with prototype data that describes a current status of the defined area of interest and a sum of vector weight values associated with the plurality of mobile sensors that represent the qualitative sensor output data; and

calculate a sparse solution of the optimization problem using the objective function and the set of constraints to determine vector weight values for each of the plurality of mobile sensors.

2. The computer system of claim 1, wherein the processor unit further executes the computer readable program code to:

determine whether there are mobile sensors in the plurality of mobile sensors with a vector weight value below a vector weight threshold value; and

remove those mobile sensors in the plurality of mobile sensors that have a vector weight value below the vector weight threshold value from the convex polygon in response to determining that there are mobile sensors in the plurality of mobile sensors with a vector weight value below the vector weight threshold value.

3. The computer system of claim 2, wherein the processor unit further executes the computer readable program code to:

reset the vector weight threshold value in response to determining that there are no mobile sensors in the plurality of mobile sensors with a vector weight value below the vector weight threshold value.

4. The computer system of claim 2, wherein the processor unit further executes the computer readable program code to:

add new mobile sensors in a neighborhood of the convex polygon that have a vector weight value above the vector weight threshold value to the convex polygon.

5. The computer system of claim 1, wherein the processor unit further executes the computer readable program code to:

generate the convex polygon using a set of mobile sensors in the plurality of mobile sensors.

6. The computer system of claim 1, wherein the processor unit further executes the computer readable program code to:

attach labels that describe a type of qualitative data being measured by the plurality of mobile sensors to the qualitative sensor output data received from the plurality of mobile sensors that form the convex polygon within the defined area of interest.

7. The computer system of claim 6, wherein the processor unit further executes the computer readable program code to:

match the labels attached to the qualitative sensor output data received from the plurality of mobile sensors that form the convex polygon with prototype data that describe the current status of the defined area of interest.

8. The computer system of claim 7, wherein the processor unit further executes the computer readable program code to:

analyze the qualitative sensor output data received from the plurality of mobile sensors that form the convex polygon based on the prototype data corresponding to the matching labels to determine the current status of the defined area of interest associated with the convex polygon.

9. The computer system of claim 8, wherein the processor unit further executes the computer readable program code to:

determine a corrective action to perform in response to determining that the current status of the defined area of interest associated with the convex polygon is outside predetermined sensor threshold limits based on the qualitative sensor output data received from the plurality of mobile sensors.

10. A computer program product stored on a non-transitory computer readable storage medium having computer readable program code encoded thereon that is executable by a computer for forming a convex polygon of a plurality of mobile sensors in a defined area of interest, the computer program product comprising:

computer readable program code for analyzing qualitative sensor output data received from the plurality of mobile sensors in the defined area of interest using an optimization problem;

computer readable program code for determining whether the plurality of mobile sensors forms the convex polygon within the defined area of interest;

computer readable program code for generating an objective function and a set of constraints corresponding to the optimization problem in response to determining that the plurality of mobile sensors does form the convex polygon within the defined area of interest, wherein the objective function is a difference between a vector associated with prototype data that describes a current status of the defined area of interest and a sum of vector weight values associated with the plurality of mobile sensors that represent the qualitative sensor output data; and

computer readable program code for calculating a sparse solution of the optimization problem using the objective function and the set of constraints to determine vector weight values for each of the plurality of mobile sensors.

11. The computer program product of claim 10, further comprising:

computer readable program code for determining whether there are mobile sensors in the plurality of mobile sensors with a vector weight value below a vector weight threshold value; and

computer readable program code for removing those mobile sensors in the plurality of mobile sensors that have a vector weight value below the vector weight threshold value from the convex polygon in response to determining that there are mobile sensors in the plurality of mobile sensors with a vector weight value below the vector weight threshold value.

12. The computer program product of claim 11 further comprising:

computer readable program code for resetting the vector weight threshold value in response to determining that there are no mobile sensors in the plurality of mobile sensors with a vector weight value below the vector weight threshold value.

13. The computer program product of claim 11 further comprising:

computer readable program code for adding new mobile sensors in a neighborhood of the convex polygon that have a vector weight value above the vector weight threshold value to the convex polygon.

14. The computer program product of claim 10 further comprising:

computer readable program code for generating the convex polygon using a set of mobile sensors in the plurality of mobile sensors.

15. The computer program product of claim 10 further comprising:

computer readable program code for attaching labels that describe a type of qualitative data being measured by the plurality of mobile sensors to the qualitative sensor output data received from the plurality of mobile sensors that form the convex polygon within the defined area of interest.

16. The computer program product of claim 15 further comprising:

computer readable program code for matching the labels attached to the qualitative sensor output data received from the plurality of mobile sensors that form the convex polygon with prototype data, that describe the current status of the defined area of interest.

17. The computer program product of claim 16, further comprising:

computer readable program code for analyzing the qualitative sensor output data received from the plurality of mobile sensors that form the convex polygon based on the prototype data corresponding to the matching labels to determine the current status of the defined area of interest associated with the convex polygon.

18. The computer program product of claim 17, further comprising:

computer readable program code for determining a corrective action to perform in response to determining that the current status of the defined area of interest associated with the convex polygon is outside predetermined sensor threshold limits based on the qualitative sensor output data received from the plurality of mobile sensors.

19. A method for forming a convex polygon of a plurality of mobile sensors in a defined area of interest, the method comprising:

analyzing, by a computer, qualitative sensor output data received from the plurality of mobile sensors in the defined area of interest using an optimization problem;

determining, by the computer, whether the plurality of mobile sensors forms the convex polygon within the defined area of interest;

responsive to the computer determining that the plurality of mobile sensors does form the convex polygon within the defined area of interest, generating, by the computer, an objective function and a set of constraints corresponding to the optimization problem, wherein the objective function is a difference between a vector associated with prototype data that describes a current status of the defined area of interest and a sum of vector weight values associated with the plurality of mobile sensors that represent the qualitative sensor output data; and

calculating, by the computer, a sparse solution of the optimization problem using the objective function and the set of constraints to determine vector weight values for each of the plurality of mobile sensors.

20. The method of claim 19 further comprising:

determining, by the computer, whether there are mobile sensors in the plurality of mobile sensors with a vector weight value below a vector weight threshold value; and

responsive to the computer determining that there are mobile sensors in the plurality of mobile sensors with a vector weight value below the vector weight threshold value, removing, by the computer, those mobile sensors in the plurality of mobile sensors that have a vector weight value below the vector weight threshold value from the convex polygon.