Mobile tag sensing and location estimation

1. A building control system, comprising:

a mobile tag, wherein the mobile tag operates to move within a structure;

a plurality of first sensors, wherein the plurality of first sensors operate to sense a first condition of the structure;

a plurality of second sensors, wherein the plurality of second sensors operate to sense a second condition of the structure;

a controller, wherein the controller operates to:

generate a first set of weighted likelihoods based on the first sensed condition of the structure, wherein the first set of weighted likelihoods includes a weighted likelihood of the mobile tag being at each one of a plurality of grid points within the structure;

generate a second set of weighted likelihoods based on the second sensed condition of the structure, wherein the second set of weighted likelihoods includes a weighted likelihood of the mobile tag being at each one of the plurality of grid points within the structure;

determine an initial location of the mobile tag at an initial time;

estimate a likelihood that at a future point in time that the mobile tag is located at each of the plurality of grid points, wherein each of the plurality of grid points is associated with a different location within the structure, comprising:

identify possible paths of the tag; and

generate a third set of weighted likelihoods of the tag being at each of the plurality of grid points based on the identified possible paths, a difference between the future point in time and the initial time, and a distance between the initial position and positions of each of the plurality of grid points;

generate a combined set of likelihoods based on the first set of weighted likelihoods, the second set of weighted likelihoods, and the third set of weighted likelihoods;

determine a distance between the mobile tag and the plurality of first sensors based on at least one beacon received from the mobile tag by the plurality of first sensors; and

estimate a location of the mobile tag within the structure based on the combined set of likelihoods and the distance determined based on the at least one beacon.

2. The system of claim 1 , wherein the first plurality of sensors comprises motion sensors, the second plurality of sensors comprises RF sensors, and wherein the combined set of likelihoods comprises an ensemble of the first set of weighted likelihoods and the second set of weighted likelihoods.

3. The system of claim 1 , wherein the first plurality of sensors comprises passive infrared (PIR) sensors and the sensed first condition of the structure comprises sensed motion of the structure.

4. The system of claim 3 , wherein the second plurality of sensors comprises wireless transceivers and the sensed second condition of the structure comprises a received signal strength of wireless signals between the mobile tag and the second plurality of sensors.

5. The system of claim 1 , wherein the controller further operates to:

group the plurality of grid points into sub-pluralities forming a plurality of convex shapes, wherein each of the sub-pluralities of grid points define a convex shape within the structure, and wherein estimating the likelihood of the tag being at each of the plurality of grid points comprises estimating a likelihood the tag is within the convex shape associated with the grid point.

6. The system of claim 5 , wherein a shape of each of the plurality of convex shapes is defined by barriers of the structure, and connecting points between each of the plurality of convex shapes are defined by openings between the barriers of the structure.

7. The system of claim 6 , wherein each of the possible paths pass through the connecting points between convex shapes.

8. The system of claim 1 , wherein the controller further operates to:

generate a fourth set of weighted likelihoods based on a physical shape of the structure or characteristics of the structure; and

generate the combined set of likelihoods based on the first set of weighted likelihoods, the second set of weighted likelihoods, and the fourth set of weighted likelihoods.

9. The system of claim 1 , wherein the controller further operates to receive a parameter sensed by the mobile tag.

10. The system of claim 9 , wherein the parameter comprises sensed acceleration of the mobile tag.

11. The system of claim 9 , wherein the parameter comprises pedometer information from the tag.

12. The system of claim 9 , wherein the parameter comprises directional information from the tag.

13. The system of claim 9 , wherein the parameter sensed magnetic information from the tag.

14. The system of claim 9 , wherein the sensed magnetic information of the tag is utilized to generate magnetic mapping of the structure.

15. A method, comprising:

sensing, by a plurality of first sensors, a first condition of the structure;

sensing, by a plurality of second sensors, a second condition of the structure;

generating a first set of weighted likelihoods based on the first sensed condition of the structure, wherein the first set of weighted likelihoods includes a weighted likelihood of a mobile tag being at each one of a plurality of grid points within the structure;

generating a second set of weighted likelihoods based on the second sensed condition of the structure, wherein the second set of weighted likelihoods includes a weighted likelihood of the mobile tag being at each one of the plurality of grid points within the structure;

determining an initial location of the mobile tag at an initial time;

estimating a likelihood that at a future point in time that the mobile tag is located at each of the plurality of grid points, wherein each of the plurality of grid points is associated with a different location within the structure, comprising:

identifying possible paths of the mobile tag;

generating a third set of weighted likelihoods of the mobile tag being at each of the plurality of grid points based on the identified possible paths, a difference between the future point in time and the initial time, and a distance between the initial position and positions of each of the plurality of grid points;

generating a combined set of likelihoods based on the first set of weighted likelihoods, the second set of weighted likelihoods, and the third set of weighted likelihoods;

determining a distance between the mobile tag and the plurality of first sensors based on at least one beacon received from the mobile tag by the plurality of first sensors; and

estimating a location of the mobile tag within the structure based on the combined set of likelihoods and the distance determined based on the at least one beacon.

16. The method of claim 15 , wherein the first plurality of sensors comprises motion sensors, the second plurality of sensors comprises RF sensors, and wherein the combined set of likelihoods comprises an ensemble of the first set of weighted likelihoods and the second set of weighted likelihoods.