Motion tracking

1. A method of tracking motion, comprising:

sensing, by a plurality of sensors of a plurality of fixtures, motion;

identifying, by a controller that receives the sense information from the plurality of sensors, a group of sensors that includes a plurality of neighboring sensors sensing motion greater than a motion threshold during a time interval;

tracking motion, by the controller, comprising:

linking the group to at least one past group of at least one past time interval, wherein the at least one past group includes a group of sensors that sensed motion during the at least one past time interval;

confirming, by the controller, that the group originated from the at least one past group of the at least one past time interval, comprising confirming that the group is located within a common area as the at least one past group, and confirming that the group includes at least one neighboring sensors of the at least one past group; and

tracking motion through a structure based on the linking of the group to the at least one past group; and

refining, by the controller, the group of sensors, comprising:

checking locations of each of the plurality of sensors of the group;

comparing the locations with locations of known obstructions; and

eliminating at least one sensor of the group that cannot be included within the group due to the location of the obstruction.

2. The method of claim 1 , wherein tracked motion of the group includes at least one of the plurality of neighboring sensors within the group being different than a plurality of sensors of the at least one past group.

3. The method of claim 1 , wherein the group of sensors is a subset of a larger set of sensors, and further comprising obtaining location data of each of the larger set of sensors, thereby allowing a determination of which of the larger set of sensors are neighboring sensors.

4. The method of claim 1 , further comprising obtaining location data of obstructions located within the larger set of sensors.

5. The method of claim 4 , further comprising determining whether the group has a proper shape, comprising analyzing the plurality of sensors of the group to determine that locations of each of the sensors of the plurality of sensors indicates maintaining the sensor within the group.

6. The method of claim 5 , determining whether the group has a proper shape includes identifying whether the group includes inactive interior sensors.

7. The method of claim 1 , wherein identifying the group of sensors that includes the plurality of neighboring sensors sensing motion greater than the threshold during a time interval comprises identifying a sensor that senses motion greater than the threshold, and then searching identified neighboring sensors of the sensor that also sense motion greater than the motion threshold during the time interval.

8. The method of claim 7 , further refining the group of sensors, comprising determining whether the group is too large.

9. The method of claim 8 , wherein if the group is determined to be too large, then splitting the group into multiple groups or eliminating one or more sensors from the group.

10. The method of claim 8 , wherein if the group is split, determining whether one of more of multiple split groups should be combined with another group.

11. The method of claim 1 , wherein tracking motion of the group comprises matching the group of a current time interval with groups of prior time intervals to determine whether a trail of motion of the group is formed over a plurality of the time intervals.

12. The method of claim 1 , further comprising confirming that the group changes are large enough to constitute motion of the group.

13. A method of tracking motion, comprising:

sensing, by a plurality of sensors of a plurality of fixtures, motion;

identifying, by a controller that receives the sense information from the plurality of sensors, a group of sensors that includes a plurality of neighboring sensors sensing motion greater than a motion threshold during a time interval;

tracking motion, by the controller, comprising:

linking the group to at least one past group of at least one past time interval, wherein the at least one past group includes a group of sensors that sensed motion during the at least one past time interval;

confirming, by the controller, that the group originated from the at least one past group of the at least one past time interval, comprising confirming that the group is located within a common area as the at least one past group, and confirming that the group includes at least one neighboring sensors of the at least one past group; and

tracking motion through a structure based on the linking of the group to the at least one past group;

designating, by the controller, the group as a child of the at least one prior group; and

evaluating, by the controller, all child groups of a prior group to determine which of the child groups provides a most likely trail of the prior group.

14. A method of tracking motion, comprising:

sensing, by a plurality of sensors of a plurality of fixtures, motion;

identifying, by a controller that receives the sense information from the plurality of sensors, a group of sensors that includes a plurality of neighboring sensors sensing motion greater than a motion threshold during a time interval;

tracking motion, by the controller, comprising:

linking the group to at least one past group of at least one past time interval, wherein the at least one past group includes a group of sensors that sensed motion during the at least one past time interval;

confirming, by the controller, that the group originated from the at least one past group of the at least one past time interval, comprising confirming that the group is located within a common area as the at least one past group, and confirming that the group includes at least one neighboring sensors of the at least one past group; and

tracking motion through a structure based on the linking of the group to the at least one past group;

designating, at the controller, the group as a child of the at least one prior group;

ranking, by the controller, each of the child groups based on at least one of a number of shared sensors, a quantity of sensors within the child group, or a direction of travel between the prior group and the child group; and

selecting, by the controller, the child group with the highest rank as the most likely trail of the prior group.

15. A system for tracking motion, comprising:

a plurality of sensors;

a controller that receives sense information from the plurality of sensors, wherein the controller is operative to:

identify a group of sensors that includes a plurality of neighboring sensors sensing motion greater than a threshold during a time interval;

track motion of the group, comprising:

linking the group to at least one past group of at least one past time interval;

confirming that the group originated from the at least one past group of the at least one past time interval, comprising confirming that the group is located within a common area as the at least one past group, confirming that the group includes at least one neighboring sensors of the at least one past group; and

tracking motion through a structure based on the linking of the group to the at least one past group; and

refine, by the controller, the group of sensors, comprising:

checking locations of each of the plurality of sensors of the group;

comparing the locations with locations of known obstructions; and

eliminating at least one sensor of the group that cannot be included within the group due to the location of the obstruction.

16. The system of claim 15 , wherein tracked motion of the group includes at least one of the plurality of neighboring sensors within the group being different than a plurality of sensors of the at least one past group.