36 results about "Daylight harvesting" patented technology

One embodiment of the present invention provides a system for calibrating a lighting control system. The lighting control system is a daylight-harvesting system that controls the output of the lighting system based on available daylight and / or other light sources to reduce energy usage while providing lighting for an area. The lighting system includes multi-level lighting capabilities for one or more light sources. First, the system measures the light levels for the area when the lighting system: is turned on at a high energy-level; is turned on at an intermediate energy-level; and is turned off. The system determines from these measured light levels the light output of the lighting system in the different states. Then, during operation, the system measures a present light level for the area. The system then adjusts the light output of the lighting system for the area based on a lighting control parameter (e.g an on set-point and an off set-point pair), the present light output of the lighting system, and the present light level for the area.

One embodiment of the present invention provides a system for preventing incorrect lighting changes in a daylight-harvesting system, which controls the output of a lighting system based on the presence of daylight and / or other light sources to reduce energy usage. During operation, the system measures a first light level using a first sensor. Next, the system measures a second light level for a different field-of-view using a second sensor. When the system detects through the first sensor a change in the first light level, the system determines from the second sensor whether the second light level has also changed. If the first sensor and the second sensor both detect a change (in the same direction) in the measured light levels, the system adjusts the light output of the lighting system to maintain target light levels for the area.

An apparatus and method for enabling an automatic calibration sequence for a light control system having a daylight harvesting scheme is disclosed herein. An ambient light sensor connects to a detection circuit for detecting the amount of ambient light within a given zone. A microprocessor connects between the detection circuit and a dimming circuit for providing control to initiate dimming and to start the auto-calibration sequence. Responsive to the amount of ambient light detected, the dimming circuit controls the power supplied to a plurality of electrical loads. A storage unit connects to the microprocessor for storing minimum light levels assessed during the auto-calibration sequence wherein the ambient light levels are monitored for a predetermined amount of time to determine the lowest level of ambient light generated for the purpose of setting and storing a target voltage level associated with such.

System and method are provided where a plurality of luminaires, control switches, occupancy detectors, and photocells are connected to a central control module including a user interface which is used for setting up, testing, commissioning and maintaining the system; a memory card interface and associated memory card which can be used to load and save configuration data, update firmware, and log system operation. Lighting system can be set up and tested and then the configuration saved in a portable memory, such as on a memory card which can be transferred to another system where it is read to facilitate faster and easier configuring of the other system to parallel, or to be exactly like, the original system. Data stored on a portable memory can be automatically recognized to perform appropriate actions such as, for example: update configuration, or update firmware. Also provided is switching between different mutually exclusive lighting modes where the lighting of each mode is sequenced such that the second lighting mode is initiated before the first mode is terminated, resulting in a continuity of lighting in the controlled area. Other features include daylight harvesting control with multiple zone dimming and switching, programmable attack and decay dimming rates, the ability to return a system to its previous dimming level after the lights have been turned off, and the ability to start the controlled lights at full light level then dim down to the previous level to ensure the lighting ballast have sufficient voltage to start up.

Disclosed is a photometer that employs high dynamic range (HDR) image processing and manipulation algorithms for capturing and measuring real-time sky conditions for processing into control input signals to a building's automated fenestration (AF) system, daylight harvesting (DH) system and HVAC system. The photometer comprises a color camera and a fitted fish-eye lens to capture 360-degree, hemispherical, low dynamic range (LDR) color images of the sky. Both camera and lens are housed in a sealed enclosure protecting them from environmental elements and conditions. In some embodiments the camera and processes are controlled and implemented by a back-end computer.

A daylight harvesting light fixture has a housing defining a light aperture, a light emitting diode (LED) in the housing for providing illumination through the aperture, a power supply for supplying drive current to the LED; a photosensor for sensing ambient illumination through the housing aperture, and a control circuit programmed and connected for a) turning off current to the LED for a dark interval imperceptible to the human eye; b) deriving an ambient illumination level signal based on the photosensor output while the LED is turned off; c) calculating an LED light output complementary to measured ambient illumination to achieve a target ambient illumination; and d) restoring drive current to the LED at a level adjusted to produce the calculated complementary LED light output. This sequence may be repeated periodically to maintain a target ambient illumination.

A flexible sheet-form optical system, referenced to as a daylighting fabric, which has a fabric-like behavior and light redirecting properties. The daylighting fabric comprises a soft and flexible sheet of optically transmissive material, such as plasticized polyvinyl chloride. A surface of the flexible sheet includes a plurality of parallel slits having spaced-apart walls configured to reflect light by means of a total internal reflection. At least a portion of daylight incident onto the sheet is internally redirected at angles other than the angle of incidence which is exploited to enhance daylight harvesting and illumination of a building interior. Disclosed also are a method and apparatus for making the daylighting fabric. The method includes steps of mechanical slitting of the flexible sheet with a blade, elastic stretch-elongation of the sheet along a direction perpendicular to the slits, and making at least a portion of the sheet elongation irreversible.

A method and means for creating a daylight harvesting controller with a self calibrating light sensor and an adaptive setpoint that maintains a user determined light level is disclosed herein. The system includes a light sensor for monitoring the ambient light level of a designated control zone and a means to receive and interpret light level adjustment commands created by a user or user surrogate. The system includes means to limit the setpoint to a maximum value, suspend daylighting activity when lights are being adjusted or are turned off, and to delay setpoint capture and the start or resumption of daylighting until an adjustment cycle is completed and the zone light sources have reached a nominally steady state.

The present invention is an apparatus, system, method, computer program, and computer program product for controlling window coverings to adjust admitted daylight. More particularly, the present disclosure plates to a control system for controlling the amount of daylight admitted through adjustable window coverings. In an embodiment of the present invention, the system includes a stand-alone open loop proportional control subsystem including a calculation or algorithm that is operable to convert a sunlight sensor signal to a blind slat position based on a predetermined curve stored in memory. In another embodiment of the present invention, the system is operable to transmit the sunlight sensor information, for example, such as in Lux, to an external system, which may then provide blind slat position requests based on some other curve, algorithm, or user need. The blind slat position may be controlled by the system to avert undesirable solar heat gains and also achieve significant daylight harvesting.

A device for cleaning a collector of a solar thermal electric power generation system is provided which does not need to secure any water source or the like and which improves the flexibility of selection of a place for installing the solar thermal electric power generation system. The cleaning device includes an air supply device and an air nozzle configured to blow air supplied from the air supply device, which are mounted on a self-propelled truck. The cleaning device is capable of blowing air blown from the air nozzle against a sunlight reflecting surface of a collector to clean up the sunlight reflecting surface. The air nozzle is configured to be capable of moving up and down. The cleaning device further includes a soiling degree measuring device for measuring soiling degrees of the sunlight reflecting surface before and after air blowing by the air nozzle.

A multi-zone daylight harvesting method and apparatus having a closed loop system utilizing a single light sensor is disclosed herein. This light control system includes an ambient light sensor connected to a detection circuit for detecting the amount of ambient light within a given zone and converting the light signal to an digital one. A control device couples to receive a predetermined rate of change for each respective zone from a storage unit along with the converted digital signal. The control device connects each zone of a plurality of electrical loads to control the power supplied to the electrical load at the predetermined corresponding rate of change and responsive to the amount of ambient light detected.

The disclosed embodiments relate to a daylight harvesting system (1). The daylight harvesting system comprises a light distribution device comprising a light inlet (2) for receiving incident light (3), and a light outlet (4) for providing output light (5) received by the light inlet into an interior space. A light sensor (6) is arranged to receive and measure a light level of the incident light and to provide a measurement signal representative thereof. Control circuitry (7) is arranged to receive the measurement signal, and to provide a control signal based on the measurement signal to an artificial light source (8) placed at the light outlet. The light sensor is placed relative the light inlet such that the incident light received by the light sensor exclusively is affected by the incident light as received by the light inlet.