Sensor fusion for low power occupancy sensing

1 . A system for detecting occupants in a room, comprising:

at least one first sensor configured to establish a background color map of the room in an unoccupied state and to detect color shift data resulting from at least one occupant entering the room;

at least one second sensor configured to determine height data of the at least one occupant; and

a controller configured to receive the color shift data and the height data and to generate equipment-control signals to operate at least one occupant-centric system,

wherein the controller is further configured to generate sensor-control signals to power on and operate the at least one second sensor in response to receiving the color shift data from the at least one first sensor.

2 . The system of claim 1 , wherein the at least one second sensor is further configured to determine velocity data of the at least one occupant and to communicate the velocity data to the controller.

3 . The system of claim 1 , wherein the at least one first sensor comprises RGB color sensors.

4 . The system of claim 1 , wherein the at least one second sensor comprises time-of-flight sensors.

5 . The system of claim 1 , wherein the at least one occupant-centric system comprises a lighting system to illuminate the room.

6 . The system of claim 1 , wherein the at least one occupant-centric system comprises an HVAC system to supply conditioned air to the room.

7 . The system of claim 1 , wherein the controller is further configured to assign a digital label to the at least one occupant for tracking the at least one occupant's position in the room.

8 . A method for detecting occupants in a room, comprising:

detecting, via a first sensor system, the spectral reflectance of the room in an unoccupied state to determine a background color map of the room;

detecting, via the first sensor system, color shift data resulting from at least one occupant entering the room and changing the spectral reflectance of the background color map;

communicating the color shift data to a controller configured to generate sensor-control signals in response to receiving the color shift data;

communicating the sensor-control signals to a second sensor system to power on and operate the second sensor system;

detecting, via the second sensor system, height data of the at least one occupant;

communicating the height data to the controller;

generating, via the controller, equipment-control signals to operate at least one occupant-centric system; and

communicating the equipment-control signals to the at least one occupant-centric systems.

9 . The method of claim 8 , further comprising:

detecting, via the second sensor system, velocity data of the at least one occupant; and

communicating the velocity data to the controller.

10 . The method of claim 8 , wherein before the step of generating equipment-control signals, further comprising:

analyzing the height data to determine whether the at least one occupant is a human.

11 . The method of claim 8 , further comprising:

assigning a digital label to the at least one occupant; and

tracking the at least one occupant's position in the room.

12 . The method of claim 8 , wherein the first sensor system comprises a plurality of RGB color sensors.

13 . The method of claim 8 , wherein the second sensor system comprises a plurality of time-of-flight sensors.

14 . The method of claim 8 , wherein the at least one occupant-centric system comprises a lighting system to illuminate the room.

15 . The method of claim 8 , wherein the at least one occupant-centric system comprises an HVAC system to supply conditioned air to the room.