Sky camera system utilizing circadian information for intelligent building control
Intelligent building control systems utilize sky information from a camera or cameras to facilitate control of building systems such as lighting, motorized window coverings, electrochromic glazings, HVAC systems, and so forth. Based on the sky information, interior lighting intensity and/or color temperature may be modified, for example in order to achieve a desired circadian effect for building occupants. In this manner, energy efficiency and occupant comfort and convenience are improved.
1. A method, comprising:
predicting for a location of interest on a building, by an automated control system and utilizing a first camera image of a sky and using a predictive algorithm, a predicted color temperature associated with the location of interest in advance of the color temperature impacting the location of interest; and
performing, by the automated control system, at least one of:
(i) communicating, to a building management system, information regarding the predicted color temperature at the location of interest in advance of the color temperature impacting the location of interest,
(ii) activating a motor to adjust a window covering associated with the location of interest in advance of the color temperature impacting the location of interest,
(iii) activating a glass controller to adjust a variable characteristic of a glass associated with the location of interest in advance of the color temperature impacting the location of interest,
(iv) communicating, to a lighting control system, information regarding the predicted color temperature at the location of interest in advance of the color temperature impacting the location of interest, or
(v) adjusting, by the automated control system, a color temperature of a lighting fixture associated with the location of interest in advance of the color temperature impacting the location of interest.
2. The method of claim 1 , wherein the first camera image is captured by a first camera disposed on the building.
3. The method of claim 1 , wherein the automated control system utilizes the first camera image and a second camera image of the sky to predict the color temperature associated with the location of interest.
4. The method of claim 3 , wherein the first camera image and the second camera image are captured by the first camera, and wherein the first camera image and the second camera image are captured at least one minute apart.
5. The method of claim 3 , wherein the first camera image is captured by a first camera disposed on the building, and wherein the second camera image is captured by a second camera at a location remote from the building.
6. The method of claim 5 , wherein the first camera image and the second camera image comprise a partially overlapping view of the sky at a common moment in time.
7. The method of claim 1 , wherein the performing is conducted gradually over a period of time.
8. The method of claim 2 , wherein the first camera is a low dynamic range camera.
9. The method of claim 2 , wherein the automated control system utilizes at least one of:
(i) an ASHRAE clear sky model, or
(ii) a CIE Standard General Sky model pursuant to ISO 15469 and/or CIE 5011.
10. The method of claim 1 , wherein the predicting the color temperature associated with the location of interest comprises:
evaluating the first camera image of the sky to obtain a baseline color temperature; and
modifying the baseline color temperature to account for at least one of: time of day, latitude, longitude, direction of view of a camera which captured the first camera image of the sky, Doppler radar information for the location of interest, or satellite imagery for the location of interest.
11. The method of claim 1 , wherein the predicting the color temperature associated with the location of interest comprises obtaining, from a color temperature sensor disposed at the location of interest, color temperature information for the location of interest.
12. The method of claim 1 , wherein the adjusting a color temperature of a lighting fixture associated with the location of interest is performed to cause a circadian response in an occupant of the location of interest.
13. The method of claim 1 , wherein automated control system performs the predicting in connection with dividing the sky into a plurality of zones, and wherein the plurality of zones are configured as a grid centered on the building.
14. The method of claim 1 , further comprising:
measuring, by a daylight sensor, a brightness level associated with the location of interest;
determining, based on the brightness level and the predicted color temperature, light exposure information for the location of interest; and
communicating, by the automated control system and to a wearable electronic device of a building occupant, the light exposure information.
15. The method of claim 14 , further comprising measuring, by the daylight sensor, a color temperature associated with the location of interest.
16. The method of claim 1 , further comprising communicating, via the lighting control system and utilizing one or more visible light fixtures, information to a wearable electronic device of a building occupant.