Visible light sensor configured for glare detection and control of motorized curtains

Abstract

The disclosure relates to a visible light sensor configured for glare detection and control of motorized curtains. A sensor may detect glare from the recorded image and may control the occlusion position of the motorized curtain based on the position of the detected glare in the image. A brightness of a pixel may be calculated in an image, and a glare condition may be detected based on the brightness of the pixel. For example, the sensor may start from a first pixel in the bottom row of pixels, and step by step through each pixel on the bottom row prior to moving to the next row of pixels. When the sensor detects a glare condition, the sensor may stop processing the remaining pixels of the image. The sensor may calculate the background brightness of the image by reordering pixels of the image from the darkest to the brightest and calculating the brightness of a predetermined percentage of pixels starting from the darkest pixel.

Description

[0001] This application is a divisional application of the application No. 202110698162.7 of the application with national application number 201880024941.5 (international application number PCT / US2018 / 020775, international application date March 2, 2018, invention name “Visible light sensor configured for glare detection and control of motorized curtains”).

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to U.S. Provisional Patent Application No. 62 / 466,696, filed on March 3, 2017, which is incorporated herein by reference in its entirety. Technical Field

[0004] The invention relates to a visible light sensor, in particular to a visible light sensor for glare detection and controlling motorized curtains. Background Art

[0005] Various types of load control systems may be used to configure a user environment, such as a residence or office building. Lighting control systems may be used to control lighting loads that provide artificial light in a user environment. Motorized window treatment control systems may be used to control the natural light provided to a user environment. HVAC systems may be used to control the temperature in a user environment.

[0006] Each load control system may include various control devices, including input devices and load control devices. The load control device may receive digital messages that may include load control instructions for controlling an electrical load from one or more input devices. The load control device may be capable of directly controlling an electrical load. The input device may be capable of indirectly controlling an electrical load through a load control device.

[0007] Examples of load control devices may include lighting control devices (e.g., dimmer switches, electronic switches, ballasts, or light emitting diode (LED) drivers), motorized window shades, temperature control devices (e.g., thermostats), and / or AC plug-in load control devices, among others. Examples of input devices may include remote control devices, occupancy sensors, daylight sensors, glare sensors, color temperature sensors, and / or temperature sensors, among others. The remote control device may receive user input for performing load control. The occupancy sensor may include an infrared (IR) sensor for detecting occupancy / vacancy of a space based on the movement of a user. The daylight sensor may detect the level of daylight received within the space. The color temperature sensor determines the color temperature within the user's environment based on the wavelength and / or frequency of the light. The temperature sensor may detect the current temperature of the space. A window sensor (e.g., a glare sensor) may be positioned facing the exterior of a building (e.g., at a window or exterior of a building) to measure the total amount of natural light detected outside the building and / or detect glare conditions.

[0008] Some prior art load control systems have controlled motorized window shades to prevent glare conditions inside buildings (e.g., glare conditions caused by direct sunlight shining into the building). The load control system may include a system controller for determining a position to which a shade fabric of the motorized window shades is controlled to prevent glare conditions based on a predicted sun position (e.g., using the current time of day and year, the location and / or orientation of the building, etc.). The load control system may automatically control the motorized window shades throughout the day based on the estimated sun position. The load control system may also include a window sensor configured to detect low light conditions (e.g., on a cloudy day) and / or high light conditions (e.g., on an extremely bright day) to enable the system controller to override automatic control of the motorized window shades on cloudy and sunny days. However, such load control systems require a complex configuration process and an advanced system controller to operate properly. These systems also perform an estimate of sunlight glare based on known conditions (e.g., the current time of day and year, the location and / or orientation of the building, etc.) and / or the total amount of sunlight sensed at a given sensor location. An example of such a load control system is described in commonly assigned U.S. Patent No. 8,288,981, issued on October 16, 2012, entitled “METHOD OF AUTOMATICALLY CONTROLLING AMOTORIZED WINDOW TREATMENT WHILE MINIMIZING OCCUPANT DISTRACTIONS,” the entire disclosure of which is incorporated herein by reference. Summary of the invention

[0009] A sensor (e.g., a visible light sensor) and / or a system controller may process an image to determine the location of a glare source and control a motorized window shade to prevent the glare source from affecting occupants of a room. A sensor (e.g., a visible light sensor) and / or a system controller may process pixels of an image to determine whether a glare condition exists. The sensor and / or the system controller may begin processing pixels at a portion of an image (e.g., the bottom or top of the image). The sensor and / or the system controller may begin processing pixels at a bottom or top row of pixels in the image and compare the brightness of the pixels to one or more thresholds to determine whether a glare condition exists (e.g., an absolute glare condition and / or a relative glare condition). The sensor and / or the system controller may stop processing the image after determining that a glare condition exists, which may simplify and / or speed up processing of the image to identify the glare condition.

[0010] After determining that a glare condition exists, the sensor and / or system controller can determine a profile angle of the glare source. The sensor and / or system controller can use the profile angle to identify locations at which the level of obstruction can be controlled at one or more motorized window coverings to prevent the glare condition from affecting occupants of the room.

[0011] As described herein, a sensor for detecting glare may include: visible light sensing circuitry configured to record one or more images; and control circuitry configured to calculate a corresponding brightness of a plurality of pixels of an image (e.g., a non-distorted image) and detect a glare condition in response to the brightness of at least one pixel. While calculating the corresponding brightness of each of the plurality of pixels, the control circuitry may be configured to start at a first pixel on a bottom row of pixels of the non-distorted image and step through each of the plurality of pixels on the bottom row before stepping to a next row of pixels immediately above the bottom row. When the control circuitry detects a glare condition, the control circuitry may stop processing the non-distorted image by not calculating the corresponding brightness of each remaining pixel of the non-distorted image.

[0012] Additionally, the control circuitry may be configured to calculate the background brightness of the image by reordering the pixels of the image from darkest to lightest and calculating the brightness of the pixel as a predetermined percentage of the distance from the darkest pixel to the lightest pixel. If the ratio of the brightness of the particular pixel to the background brightness is greater than a predetermined contrast threshold, the control circuitry may be configured to detect a glare condition. Although the sensor may be described as performing image processing for detecting a glare condition to control the level of shading of the motorized window covering, the system controller or another image processing device may perform similar functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a simplified diagram of an example load control system having a visible light sensor.

[0014] Figure 2 is a side view of an example space with a visible light sensor.

[0015] Figure 3 is a simplified block diagram of an example visible light sensor.

[0016] Figure 4 A flow chart of an example glare detection process is shown.

[0017] Figure 5A and 5B A flow chart showing an example glare detection process that may be performed by control circuitry of a visible light sensor is shown.

[0018] Figure 6 A flow chart showing a simplified process for determining background brightness.

[0019] Fig. 7A A simplified sequence diagram of an example glare detection process that may be performed by a visible light sensor and a motorized window shade is shown.

[0020] Figure 7B A simplified sequence diagram of an example glare detection process that may be performed by a visible light sensor, a system controller, and a motorized window shade is shown.

[0021] Figure 8 is a simplified example of a non-distorted image used for glare detection.

[0022] Fig. 9 is a block diagram of an example system controller.

[0023] Fig.10 is a block diagram of an example control target device. DETAILED DESCRIPTION

[0024] Figure 1 1 is a simplified diagram of an example load control system 100 for controlling the amount of power delivered to one or more electrical loads from an alternating current (AC) power source (not shown). The load control system 100 may be installed in a room 102 of a building. The load control system 100 may include a plurality of control devices configured to communicate with each other via wireless signals (e.g., radio frequency (RF) signals 108). Alternatively or additionally, the load control system 100 may include a wired digital communication link coupled to one or more control devices to provide communication between the load control devices. The control devices of the load control system 100 may include a plurality of control source devices (e.g., input devices operable to send digital messages in response to user input, occupancy / vacancy conditions, changes in measured light intensity, etc.) and a plurality of control target devices (e.g., load control devices operable to receive digital messages and control corresponding electrical loads in response to the received digital messages). A single control device of the load control system 100 may operate as a control source and a control target device.

[0025] The control source device may be configured to send the digital message directly to the control target device. In addition, the load control system 100 may include a system controller 110 (e.g., a central processing unit or a load controller) that is operable to transmit digital messages to and from control devices (e.g., control source devices and / or control target devices). For example, the system controller 110 may be configured to receive a digital message from a control source device and to send the digital message to the control target device in response to the digital message received from the control source device. The control source and control target devices and the system controller 110 may be configured to communicate using a proprietary RF protocol (e.g., The RF signal 108 may be transmitted using a different RF protocol, such as a standard protocol such as WIFI, ZIGBEE, Z-WAVE, KNX-RF, ENOCEAN RADIO protocol, or one of different proprietary protocols.

[0026] The load control system 100 may include one or more load control devices, such as a dimmer switch 120 for controlling a lighting load 122. The dimmer switch 120 may be adapted to be wall mounted in a standard electrical wall box. The dimmer switch 120 may include a tabletop or plug-in load control device. The dimmer switch 120 may include a switching actuator (e.g., a push button) and an intensity adjustment actuator (e.g., a rocker switch). Actuation (e.g., continuous actuation) of the switching actuator may switch (e.g., turn off and on) the lighting load 122. Actuation of the upper or lower portion of the intensity adjustment actuator may increase or decrease the amount of power delivered to the lighting load 122, respectively, thereby increasing or decreasing the intensity of the receiving lighting load from a minimum intensity (e.g., approximately 1%) to a maximum intensity (e.g., approximately 100%). The dimmer switch 120 may include a plurality of visual indicators, such as light emitting diodes (LEDs), which may be arranged in a linear array and illuminated to provide feedback of the intensity of the lighting load 122. Examples of wall-mounted dimmer switches are described in more detail below: U.S. Patent No. 5,248,919, entitled LIGHTING CONTROL DEVICE, issued on September 28, 1993, and U.S. Patent No. 5,676,696, entitled WIRELESS LOAD CONTROLDEVICE, issued on June 13, 2017, the entire disclosures of which are incorporated herein by reference.

[0027] The dimmer switch 120 can be configured to wirelessly receive digital messages via the RF signal 108 (e.g., from the system controller 110) and control the lighting load 122 in response to the received digital messages. Examples of dimmer switches operable to send and receive digital messages are described in more detail below: in commonly assigned U.S. Patent Application Publication No. 2009 / 0206983, entitled “COMMUNICATION PROTOCOL FOR A RADIO-FREQUENCY LOAD CONTROL SYSTEM,” published on August 20, 2009, the entire disclosure of which is incorporated herein by reference.

[0028] The load control system 100 may include one or more remotely located load control devices, such as a light emitting diode (LED) driver 130 for driving an LED light source 132 (e.g., an LED light engine). The LED driver 130 may be remotely located, such as in or near a lighting fixture of the LED light source 132. The LED driver 130 may be configured to receive a digital message via the RF signal 108 (e.g., from the system controller 110) and control the LED light source 132 in response to the received digital message. The LED driver 130 may be configured to adjust the color temperature of the LED light source 132 in response to the received digital message. An example of an LED driver configured to control the color temperature of an LED light source is described in more detail below: commonly assigned U.S. Patent No. 9,538,603, entitled “SYSTEMS AND METHODS FOR CONTROLLING COLOR TEMPERATURE,” issued on January 3, 2017, the entire disclosure of which is incorporated herein by reference. The load control system 100 may also include other types of remotely located load control devices, such as electronic dimming ballasts for driving fluorescent lamps.

[0029] The load control system 100 may include a plug-in load control device 140 for controlling a plug-in electrical load, such as a plug-in lighting load (e.g., a floor lamp 142 or a table lamp) and / or an appliance (e.g., a television or a computer monitor). For example, a floor lamp 142 may be plugged into the plug-in load control device 140. The plug-in load control device 140 may be plugged into a standard electrical outlet 144 and may thus be coupled in series between the AC power source and the plug-in lighting load. The plug-in load control device 140 may be configured to receive a digital message via the RF signal 108 (e.g., from the system controller 110) and, in response to the received digital message, turn the floor lamp 142 on and off or adjust the intensity.

[0030] Alternatively or additionally, the load control system 100 may include a controllable outlet for controlling a plug-in electrical load plugged into the outlet. The load control system 100 may include one or more load control devices or appliances capable of receiving the wireless signal 108 directly from the system controller 110, such as a speaker 146 (e.g., part of an audio / visual or intercom system) that can generate sounds such as an alarm, music, intercom functions, etc.

[0031] The load control system 100 may include one or more daylight control devices, such as motorized window shades 150, such as motorized cellular shades, for controlling the amount of daylight entering the room 102. Each motorized window shade 150 may include a window shade fabric 152 suspended from a window shade box 154 in front of a corresponding window 104. Each motorized window shade 150 may also include a motor drive unit (not shown) located inside the window shade box 154 for raising and lowering the window shade fabric 152 to control the amount of daylight entering the room 102. The motor drive unit of the motorized window shade 150 may be configured to receive digital messages via the RF signal 108 (e.g., from the system controller 110) and adjust the position of the corresponding window shade fabric 152 in response to the received digital information. The load control system 100 may include other types of daylight control devices, such as cellular shades, valances, Roman shades, blinds, Persian shades, pleated blinds, tensioned roller blinds, electrochromic or smart windows, and / or other suitable daylight control devices. Examples of battery-powered motorized window treatments are described in more detail below: U.S. Patent No. 8,950,461, entitled “MOTORIZED WINDOW TREATMENT,” issued on February 10, 2015, and U.S. Patent No. 9,488,000, entitled “INTEGRATED ACCESSIBLE BATTERY COMPARTMENT FOR MOTORIZED WINDOWTREATMENT,” issued on November 8, 2016, the entire disclosures of which are incorporated herein by reference.

[0032] The load control system 100 may include one or more temperature control devices, such as a thermostat 160 for controlling the room temperature in the room 102. The thermostat 160 may be coupled to a heating, ventilation, and air conditioning (HVAC) system 162 via a control link (e.g., an analog control link or a wired digital communication link). The thermostat 160 may be configured to wirelessly communicate digital messages with a controller of the HVAC system 162. The thermostat 160 may include a temperature sensor for measuring the room temperature of the room 102, and may control the HVAC system 162 to adjust the temperature in the room to a set point temperature. The load control system 100 may include one or more wireless temperature sensors (not shown) located in the room 102 for measuring the room temperature. The HVAC system 162 may be configured to turn on and off a compressor to cool the room 102 and turn on and off a heating source to heat the room in response to a control signal received from the thermostat 160. The HVAC system 162 may be configured to turn on and off a fan of the HVAC system in response to a control signal received from the thermostat 160. Thermostat 160 and / or HVAC system 162 may be configured to control one or more controllable dampers to control air flow in room 102. Thermostat 160 may be configured to receive digital messages via RF signal 108 (e.g., from system controller 110) and adjust heating, ventilation, and cooling in response to the received digital messages.

[0033] The load control system 100 may include one or more other types of load control devices, including, for example: a screw-in lamp including a dimmer circuit and an incandescent or halogen lamp; a screw-in lamp including a ballast and a compact fluorescent lamp; a screw-in lamp including an LED driver and an LED light source; an electronic switch, a controllable circuit breaker, or other switching device for turning an electrical appliance on and off; a plug-in load control device, a controllable electrical outlet, or a controllable power strip for controlling one or more plug-in loads; a motor control unit for controlling a motor load, such as a ceiling fan or an exhaust fan; a drive unit for controlling a motorized window shade or projection screen; a motorized interior or exterior blinds for heating and / or cooling systems; thermostats for heating and / or cooling systems; temperature control devices for controlling set point temperatures for HVAC systems; air conditioners; compressors; electric baseboard heater controllers; controllable dampers; variable air volume controllers; fresh air intake controllers; ventilation controllers; hydraulic valves for radiators and radiant heating systems; humidity control units; humidifiers; dehumidifiers; water heaters; boiler controllers; pool pumps; refrigerators; freezers; television or computer monitors; video cameras; audio systems or amplifiers; elevators; power supplies; generators; chargers, such as motor vehicle chargers; and, alternative energy controllers.

[0034] The load control system 100 may include one or more input devices, such as a remote control device 170, a first visible light sensor 180 (e.g., a room sensor), and a second visible light sensor 182 (e.g., a window sensor). The input device may be a fixed or movable input device. The system controller 110 may be configured to send one or more digital messages to the load control device (e.g., the dimmer switch 120, the LED driver 130, the plug-in load control device 140, the motorized curtain 150, and / or the thermostat 160) in response to digital messages received from the remote control device 170 and the visible light sensors 180, 182. The remote control device 170 and the visible light sensors 180, 182 may be configured to send digital messages directly to the dimmer switch 120, the LED driver 130, the plug-in load control device 140, the motorized curtain 150, and the temperature control device 160.

[0035] The remote control device 170 can be configured to send a digital message to the system controller 110 (e.g., directly to the system controller) via the RF signal 108 in response to actuation of one or more buttons of the remote control device. For example, the remote control device 170 can be battery powered. The load control system 100 can include other types of input devices, such as temperature sensors, humidity sensors, radiometers, cloud sensors, occlusion sensors, pressure sensors, smoke detectors, carbon monoxide detectors, air quality sensors, motion sensors, security sensors, proximity sensors, fixture sensors, partition sensors, keyboards, multi-zone control units, slider control units, kinetic or solar powered remote controls, key fobs, cellular phones, smart phones, tablet computers, personal digital assistants, personal computers, notebook computers, time locks, audio-visual controls, security devices, power monitoring devices (e.g., electric meters, energy meters, utility cost meters, utility rate meters, etc.), central control transmitters, residential, commercial, or industrial controllers, and / or any combination thereof.

[0036] The system controller 110 can be coupled to a network such as a wireless or wired local area network (LAN) for example, to access the Internet. The system controller 110 can be wirelessly connected to the network, for example, using Wi-Fi technology. The system controller 110 can be coupled to the network via a network communication bus (e.g., an Ethernet communication link). The system controller 110 can be configured to communicate with one or more network devices via the network, such as a mobile device 190, such as a personal computing device and / or a wearable wireless device. The mobile device 190 can be located on an occupant 192, for example, can be attached to the occupant's body or clothing, or can be held by the occupant. The mobile device 190 can be characterized by a unique identifier (e.g., a serial number or address stored in a memory) that uniquely identifies the mobile device 190 and therefore identifies the occupant 192. Examples of personal computing devices can include smart phones (e.g., Smartphone, Smartphone or smartphones), laptops and / or tablet devices (e.g. Handheld computing devices). Examples of wearable wireless devices may include activity tracking devices such as equipment, Device and / or Sony devices), smart watches, smart clothing (e.g. smart clothing, etc.) and / or smart glasses (e.g., Google In addition, the system controller 110 may be configured to communicate with one or more other control systems (eg, a building management system, a security system, etc.) via a network.

[0037] The mobile device 190 may be configured to send digital messages to the system controller 110, for example, in one or more Internet Protocol packets. For example, the mobile device 190 may be configured to send digital messages to the system controller 110 over a LAN and / or via the Internet. The mobile device 190 may be configured to send digital messages to an external service (e.g., If This Then That The digital message may then be received by the system controller 110. The mobile device 190 may send and receive the RF signal 109 via a Wi-Fi communication link, a Wi-MAX communication link, a Bluetooth communication link, a near field communication (NFC) link, a cellular communication link, a television white space (TVWS) communication link, or any combination thereof. Alternatively or additionally, the mobile device 190 may be configured to send the RF signal according to a proprietary protocol. The load control system 100 may include other types of network devices coupled to the network, such as a desktop personal computer, a Wi-Fi or television with wireless communication capabilities, or any other suitable Internet protocol-enabled device. An example of a load control system operable to communicate with a mobile and / or network device on a network is described in more detail below: U.S. Patent Application Publication No. 2013 / 0030589, commonly assigned and published on January 31, 2013, entitled LOAD CONTROL DEVICE HAVING INTERNET CONNECTIVITY, the entire disclosure of which is incorporated herein by reference.

[0038] The system controller 110 can be configured to determine the location of the mobile device 190 and / or the occupant 192. The system controller 110 can be configured to control (e.g., automatically control) a load control device (e.g., a dimmer switch 120, an LED driver 130, a plug-in load control device 140, a motorized window shade 150, and / or a temperature control device 160) in response to determining the location of the mobile device 190 and / or the occupant 192. One or more of the control devices of the load control system 100 can transmit a beacon signal, for example, an RF beacon signal transmitted using a short-range and / or low-power RF technology such as Bluetooth technology. The load control system 100 can also include at least one beacon transmitting device 194 for transmitting the beacon signal. The mobile device 190 can be configured to receive the beacon signal when it is located near a control device that is currently transmitting the beacon signal. The beacon signal can include a unique identifier that identifies the location of the load control device that transmitted the beacon signal. Since the beacon signal can be transmitted using a short-range and / or low-power technology, the unique identifier can indicate the approximate location of the mobile device 190. The mobile device 190 can be configured to send the unique identifier to the system controller 110, which can be configured to use the unique identifier to determine the location of the mobile device 190 (e.g., using data stored in a memory or retrieved via the Internet). An example of a load control system for controlling one or more electrical loads in response to the location of a mobile device and / or occupant within a building is described in more detail below: commonly assigned U.S. Patent Application Publication No. 2016 / 0056629, entitled “LOAD CONTROL SYSTEM RESPONSIVE TO LOCATION OF AN OCCUPANT AND MOBILE DEVICES,” published on February 25, 2016, the entire disclosure of which is incorporated herein by reference.

[0039] Visible light sensors 180, 182 may each include, for example, a camera and a fisheye lens. The camera of first visible light sensor 180 may be directed into room 102 and may be configured to record an image of room 102. For example, first visible light sensor 180 may be mounted to a ceiling of room 102 (e.g., Figure 1 102 ) and / or may be mounted on a wall of a room. If first visible light sensor 180 is mounted to the ceiling, the image recorded by the camera may be a top view of room 102. The camera of second visible light sensor 182 may be directed to the exterior of room 102 (e.g., outside window 104) and may be configured to record images from outside the building. For example, second visible light sensor 182 may be mounted to one of windows 104 (e.g., Figure 1as shown) and / or can be mounted to the exterior of a building.

[0040] Each of the visible light sensors 180, 182 can be configured to process the image recorded by the camera and send one or more messages (e.g., digital messages) to the load control device in response to the processed image. Each visible light sensor 180, 182 can be configured to sense one or more environmental features of the space (e.g., room 102 and / or room 200) from the image. For example, the first visible light sensor 180 can be configured to operate in one or more sensor modes (e.g., occupancy and / or vacancy sensor mode, daylight sensor mode, color sensor mode, glare detection sensor mode, occupant counting mode, etc.). In addition, the second visible light sensor 182 can be configured to operate in one or more of the same or different sensor modes (e.g., color sensor mode, glare detection sensor mode, weather sensor mode, etc.). Each visible light sensor 180, 182 can execute different algorithms to process the image in each sensor mode to determine the data to be transmitted to the load control device. Each of the visible light sensors 180, 182 can send a digital message via the RF signal 108 (e.g., using a proprietary protocol) in response to the image. Visible light sensors 180, 182 may each send digital messages directly to the load control device and / or system controller 110, which may then communicate the message to the load control device. Each visible light sensor 180, 182 may include a first communication circuit for sending and receiving RF signals 108 using a proprietary protocol.

[0041] Each of visible light sensors 180, 182 can be configured to perform multiple sensor events to sense various environmental features inside and / or outside of room 102. For example, to perform a sensor event, each visible light sensor 180, 182 can be configured to operate in one of multiple sensor modes to execute one or more corresponding algorithms to sense environmental features. In addition, each visible light sensor 180, 182 can be configured to obtain certain pre-configured operating characteristics (e.g., sensitivity, baseline value, threshold value, limit value, etc.) from a memory that can be used by the algorithm to sense features of the environment during a sensor event.

[0042] In addition, each visible light sensor 180, 182 can be configured to focus on one or more areas of interest in the image recorded by the camera when processing the image to sense environmental features during the sensor event. For example, certain areas of the image recorded by the camera of one of the visible light sensors 180, 182 can be masked (e.g., digitally masked) so that the corresponding visible light sensor may not process the portion of the image in the masked area. Each visible light sensor 180, 182 can be configured to apply a mask (e.g., a predetermined digital mask that can be stored in a memory) to focus on a specific area of ​​interest and process the image portion in the area of ​​interest. In addition, each visible light sensor 180, 182 can be configured to focus on multiple areas of interest in the image at the same time. One or more specific masks can be defined for each sensor event.

[0043] Each of the visible light sensors 180, 182 can be configured to dynamically change between sensor modes, apply a digital mask to an image, and / or adjust operating characteristics based on the current sensor event. Each visible light sensor 180, 182 can be configured to perform multiple different sensor events to sense multiple environmental features of a space. For example, each visible light sensor 180, 182 can be configured to sequentially and / or periodically step through sensor events to sense multiple environmental features of a space. Each sensor event can be characterized by a sensor mode (e.g., specifying an algorithm to be used), one or more operating characteristics, and / or one or more digital masks. An example of a visible light sensor with multiple sensor modes is described in more detail below: U.S. Patent Application Publication No. 2017 / 0171941, a commonly assigned patent application published on June 15, 2017, entitled "LOAD CONTROL SYSTEM HAVING A VISIBLE LIGHT SENSOR", the entire disclosure of which is incorporated herein by reference.

[0044] First visible light sensor 180 can be configured to operate in an occupancy and / or vacancy sensor mode to determine occupancy and / or vacancy conditions in room 102 in response to detecting movement within one or more areas of interest. First visible light sensor 180 can be configured to use an occupancy and / or vacancy detection algorithm to determine that room 102 is occupied in response to an amount of movement and / or a speed of movement exceeding an occupancy threshold.

[0045] During a sensor event for detecting occupancy and / or vacancy, the first visible light sensor 180 may be configured to apply a predetermined mask to focus on one or more regions of interest in one or more images recorded by the camera, and determine occupancy or vacancy of the space based on detection or non-detection of motion in the region of interest. The first visible light sensor 180 may respond to movement in the region of interest without responding to movement in the obscured region. For example, the first visible light sensor 180 may be configured to apply a mask to an image of a room to exclude detection of motion in the doorway 108 and / or window 104 of the room 102, and may focus on a region of interest including the interior space of the room. The first visible light sensor 180 may be configured to apply a first mask to focus on a first region of interest, apply a second mask to focus on a second region of interest, and determine occupancy or vacancy based on movement detected in any region of interest. In addition, the first visible light sensor 180 may be configured to simultaneously focus on multiple regions of interest in an image by applying different masks to one or more images.

[0046] The first visible light sensor 180 can be configured to adjust certain operating characteristics (e.g., sensitivity) to be used by the occupancy and / or vacancy algorithms based on the current sensor event. The occupancy threshold may depend on the sensitivity. For example, the first visible light sensor 180 can be configured to be more or less sensitive to movement in a first area of ​​interest than to movement in a second area of ​​interest. For example, the first visible light sensor 180 can be configured to increase sensitivity and apply a mask to focus on the area of ​​interest around a computer keyboard to be more sensitive to movement around the keyboard. In other words, by using a mask that focuses on "smaller" versus "larger" (e.g., keyboard versus the desktop on which the keyboard can sit), the first visible light sensor 180 can be configured to increase and / or decrease the sensitivity of detected or undetected motion. In addition, by using a mask, the first visible light sensor 180 can be configured to detect not only movement in space, but also the location where the movement occurs.

[0047] First visible light sensor 180 may send a digital message to system controller 110 via RF signal 108 (e.g., using a proprietary protocol) in response to detecting an occupied or vacant condition. System controller 110 may be configured to turn lighting loads (e.g., lighting loads 122 and / or LED light sources 132) on and off in response to receiving an occupied command and a vacant command, respectively. Alternatively, first visible light sensor 180 may send a digital message directly to the lighting loads. First visible light sensor 180 may operate as a vacancy sensor such that the lighting loads are turned off only in response to detecting a vacancy condition (e.g., and not turned on in response to detecting an occupied condition). Examples of RF load control systems with occupancy and vacancy sensors are described in more detail below: U.S. Patent No. 8,009,042, entitled “RADIO-FREQUENCYLIGHTING CONTROL SYSTEM WITH OCCUPANCY SENSING,” issued on August 30, 2011, and commonly assigned on September 3, 2008; U.S. Patent No. 8,199,010, entitled “METHOD AND APPARATUS FOR CONFIGURING A WIRELESS SENSOR,” issued on June 12, 2012; and U.S. Patent No. 8,228,184, entitled “BATTERY-POWEREDOCCUPANCY SENSOR,” issued on July 24, 2012, the entire disclosures of which are incorporated herein by reference.

[0048] The first visible light sensor 180 can also be configured to operate in a daylight sensor mode to measure light intensity at a spatial location. For example, the first visible light sensor 180 can apply a digital mask to focus only on the spatial location (e.g., on a work surface, such as Figure 1 106) and a daylight algorithm can be used to measure the light intensity at that location. For example, first visible light sensor 180 can be configured to apply a mask to focus on an area of ​​interest that includes the tabletop. First visible light sensor 180 can be configured to integrate the light intensity values ​​of pixels of the image over the area of ​​interest to determine a measured light intensity at the tabletop.

[0049] First visible light sensor 180 may send a digital message (e.g., including the measured light intensity) to system controller 110 via RF signal 108 to control the intensity of lighting load 122 and / or LED light source 132 in response to the measured light intensity. First visible light sensor 180 may be configured to focus on multiple regions of interest in an image recorded by a camera and measure the light intensity in each different region of interest. Alternatively, first visible light sensor 180 may send the digital message directly to the lighting load. First visible light sensor 180 may be configured to adjust certain operating characteristics (e.g., gain) based on the region of interest in which the light intensity is currently being measured. Examples of RF load control systems with daylight sensors are described in more detail below: commonly assigned U.S. Patent No. 8,410,706, issued on April 2, 2013, entitled “METHOD OF CALIBRATING ADAYLIGHT SENSOR”; and, U.S. Patent No. 8,451,116, issued on May 28, 2013, entitled “WIRELESS BATTERY-POWERED DAYLIGHT SENSOR,” the entire disclosures of which are incorporated herein by reference.

[0050] The system controller 110 may be configured to determine degradation of the light output of one or more lighting loads (e.g., lighting load 122 and / or LED light source 132) in the space, and control the intensity of the lighting load to compensate for the degradation (e.g., lumen maintenance). For example, the system controller 110 may be configured to turn on each lighting load individually (e.g., when it is dark at night) and measure the magnitude of the light intensity at a location (e.g., on table 106 or desk 220). For example, the system controller 110 may be configured to turn on the lighting load 122 at night and control the first visible light sensor 180 to record an image of the room to apply a mask to focus on an area of ​​interest illuminated by the lighting load 122 (e.g., the surface of the table 106 or desk 220) to measure the light intensity in the area of ​​interest, and transmit the value to the system controller 110. The system controller 110 may store the value as a baseline value. At a subsequent time and / or date, the system controller 110 may repeat the measurement and compare the measurement result with the baseline value. If the system controller 110 determines that degradation exists, it may control the lighting loads 122 to compensate for the degradation, alarm maintenance, etc.

[0051] The first visible light sensor 180 may also be configured to operate in a color sensor mode to sense the color (e.g., measure the color temperature) of light emitted by one or more lighting loads in the space (e.g., to operate as a color sensor and / or a color temperature sensor). For example, the first visible light sensor 180 may be configured to apply a mask to focus on an area of ​​interest in the room 102, and may use a color sensing algorithm to determine the measured color and / or color temperature in the room. For example, the first visible light sensor 180 may integrate the color values ​​of the pixels of the image over the area of ​​interest to determine the measured color and / or color temperature in the room. The first visible light sensor 180 may send a digital message (e.g., including the measured color temperature) to the system controller 110 via the RF signal 108 to control the color (e.g., color temperature) of the lighting load 122 and / or the LED light source 132 in response to the measured light intensity (e.g., color tuning of the light in the space). Alternatively, the first visible light sensor 180 may send the digital message directly to the lighting load. An example of a load control system for controlling the color temperature of one or more lighting loads is described in more detail below: commonly assigned U.S. Patent No. 9,538,603, entitled “SYSTEMS AND METHODS FOR CONTROLLING COLOR TEMPERATURE,” issued on January 3, 2017, the entire disclosure of which is incorporated herein by reference.

[0052] The first visible light sensor 180 may be configured to operate in a glare detection sensor mode. For example, the first visible light sensor 180 may be configured to execute a glare detection algorithm to determine the depth of direct sunlight penetrating into the space from the image recorded by the camera. For example, the first visible light sensor 180 may be configured to apply a mask to focus on an area of ​​interest on the floor of the room 102 near the window 104 to sense the depth of direct sunlight penetrating into the room. Based on the detection and / or measurement of the depth of direct sunlight penetrating into the room, the first visible light sensor 180 may send a digital message to the system controller 110 via the RF signal 108 to limit the depth of direct sunlight penetrating into the space, for example, to prevent direct sunlight from shining on a surface (e.g., a table or desk). The system controller 110 may be configured to lower the curtain fabric 152 of each motorized curtain 150 to prevent the depth of direct sunlight penetrating from exceeding the maximum sunlight penetration depth. Alternatively, the first visible light sensor 180 may be configured to directly control the curtain 150 to the lower portion of the curtain fabric 152. An example of a method for limiting the depth of sunlight penetration in a space is described in more detail in previously referenced U.S. Patent No. 8,288,981.

[0053] The first visible light sensor 180 can be configured to focus only on daylight entering the space through, for example, one or both of the windows 104 (to function, for example, as a window sensor). The system controller 110 can be configured to control the lighting load (e.g., the lighting load 122 and / or the LED light source 132) in response to the amount of daylight entering the space. The system controller 110 can be configured to override automatic control of the motorized window treatment 150, for example, in response to determining that it is an overcast day or a very sunny day. Alternatively, the first visible light sensor 180 can be configured to directly control the window treatment 150 to the lower portion of the window treatment fabric 152. An example of a load control system with a window sensor is described in more detail below: commonly assigned U.S. Patent Application Publication No. 2014 / 0156079, published on June 5, 2014, entitled “METHOD OF CONTROLLING A MOTORIZED WINDOW TREATMENT”, the entire disclosure of which is incorporated herein by reference.

[0054] The first visible light sensor 180 can be configured to detect a source of glare (e.g., sunlight reflected from a surface) outside or inside the room 102 in response to the image recorded by the camera. The system controller 110 can be configured to lower the curtain fabric 152 of each motorized curtain 150 to eliminate the glare source. Alternatively, the first visible light sensor 180 can be configured to directly control the curtain 150 to the lower portion of the curtain fabric 152 to eliminate the glare source.

[0055] The first visible light sensor 180 may also be configured to operate in an occupant counting mode and may execute an occupant counting algorithm to count the number of occupants of a particular area of ​​interest and / or the number of occupants entering and / or leaving the area of ​​interest. For example, the system controller 110 may be configured to control the HVAC system 162 in response to the number of occupants in the space. The system controller 110 may be configured to control one or more load control devices of the load control system 100 in response to the number of occupants in the space exceeding an occupancy number threshold. Alternatively, the first visible light sensor 180 may be configured to directly control the HVAC system 162 and other load control devices.

[0056] The second visible light sensor 182 may be configured to operate in a glare detection sensor mode. For example, the second visible light sensor 182 may be configured to execute a glare detection algorithm to determine whether a glare condition may exist in the room 102 based on one or more images recorded by the camera. The glare condition in the room 102 may be caused by a glare source outside the room, such as the sun, an external light (e.g., an outdoor building light or a street light), and / or a reflection of the sun or other bright light source. The second visible light sensor 182 may be configured to analyze the one or more images recorded by the camera to determine whether an absolute glare condition and / or a relative glare condition exist outside the room 102 when viewed from one of the windows 104. An absolute glare condition may occur when the light level (e.g., light intensity) of a potential glare source is too high (e.g., exceeds an absolute glare threshold). A relative glare condition (e.g., a contrast glare condition) may occur when the difference between the light level of a potential glare source and a background light level (e.g., a baseline) is too high (e.g., exceeds a relative glare threshold).

[0057] Based on the detection of the glare condition, the second visible light sensor 182 can send a digital message to the system controller 110 via the RF signal 108 to open, close, or adjust the position of the curtain fabric 152 of each motorized curtain 150. For example, the system controller 110 can be configured to lower the curtain fabric 152 of each motorized curtain 150 to prevent direct sunlight from penetrating into a work surface (e.g., a desk or table) in the room 102. If the second visible light sensor 182 does not detect a glare condition, the system controller 110 can be configured to open the motorized curtain 150 (e.g., to control the position of the curtain fabric 152 to a fully open position or a visor position). Alternatively, the second visible light sensor 182 can be configured to directly control the curtain 150.

[0058] The operation of the load control system 100 may be programmed and configured using, for example, the mobile device 190 or other network device (e.g., when the mobile device is a personal computing device). The mobile device 190 may execute a graphical user interface (GUI) configuration software to allow a user to program how the load control system 100 will operate. For example, the configuration software may run as a PC application or a web interface. The configuration software and / or the system controller 110 (e.g., through instructions from the configuration software) may generate a load control database that defines the operation of the load control system 100. For example, the load control database may include information about the operational settings of different load control devices (e.g., dimmer switches 120, LED drivers 130, plug-in load control devices 140, motorized window shades 150, and / or thermostats 160) of the load control system. The load control database may include information about associations between load control devices and input devices (e.g., remote control devices 170, visible light sensors 180, etc.). The load control database may include information about how the load control devices respond to inputs received from the input devices. Examples of configuration processes for load control systems are described in more detail below: commonly assigned U.S. Patent No. 7,391,297, issued on June 24, 2008, entitled “HANDHELD PROGRAMMER FOR A LIGHTING CONTROL SYSTEM”; U.S. Patent Application Publication No. 2008 / 0092075, published on April 17, 2008, entitled “METHOD OF BUILDING A DATABASE OF A LIGHTING CONTROL SYSTEM”; and, U.S. Patent Application Publication No. 2014 / 0265568, published on September 18, 2014, entitled “COMMISSIONING LOAD CONTROL SYSTEMS”, the entire disclosures of which are incorporated herein by reference.

[0059] The operation of the visible light sensors 180, 182 may be programmed and configured using a mobile device 190 or other network device. Each visible light sensor 180, 182 may include a second communication circuit for sending and receiving RF signals 109 (e.g., directly with the network device 190 using a standard protocol such as Wi-Fi or Bluetooth). During the configuration process of the load control system 100, each of the visible light sensors 180, 182 may be configured to record an image of the space and send the image to the network device 190 (e.g., directly to the network device via the RF signal 109 using a standard protocol). The network device 190 may display the image on a visual display, and a user may configure the operation of each visible light sensor 180, 182 to set one or more configuration parameters (e.g., configuration information) of the visible light sensor. For example, for different environmental features sensed and controlled by the visible light sensors 180, 182 (e.g., occupant movement, light levels in the room, daylight levels outside the room), the user may indicate different areas of interest on the image by tracing (e.g., with a finger or stylus) an occluded area on the image displayed on the visual display. Visible light sensors 180 , 182 may each be configured to establish different masks and / or operating characteristics depending on the environmental characteristics to be sensed (eg, occupant movement, light levels within the room, daylight levels outside the room, color temperature, etc.).

[0060] After configuration of visible light sensors 180, 182 is completed at network device 190, the network device may send configuration information to the visible light sensors (e.g., directly to the visible light sensors via RF signal 109 using a standard protocol). Visible light sensors 180, 182 may each store the configuration information in a memory so that the visible light sensors may operate appropriately during normal operation. For example, for each sensor event that visible light sensors 180, 182 are to monitor, network device 190 may transmit to the corresponding visible light sensor a sensor mode for the event, one or more masks defining an area of ​​interest for the event, an indication of an algorithm that may be used to sense environmental characteristics of the event, and one or more operational characteristics of the event.

[0061] Although the above description has been made with reference to the two visible light sensors 180, 182 Figure 1The load control system 100 of FIG. 100 may include any one of the visible light sensors 180, 182, but the load control system 100 may also simply include any one of the visible light sensors 180, 182. For example, the load control system 100 may not include the first visible light sensor 180 and may include only the second visible light sensor 182, which may be mounted to the window 104 and may operate to prevent solar glare from occurring on work surfaces in the room 102. In addition, the load control system 100 may have more than two visible light sensors. Each window may have a corresponding visible light sensor, or the visible light sensor may receive an image through a window that represents a group of windows having motorized window shades that are collectively controlled based on an image from a single visible light sensor.

[0062] Figure 2 is a visible light sensor 210 (e.g., Figure 1 1 and 1 . A simplified side view of an example space 200 of a load control system 100 is shown with a second visible light sensor 182 of the load control system 100 shown in FIG. 2 . The visible light sensor 210 can be mounted to a window 202, which can be located in a facade 204 of a building in which the space 200 is located and can allow light (e.g., sunlight) to enter the space. The visible light sensor 210 can be mounted to an interior surface of the window 202 (e.g., such as Figure 2 202. The window 202 may be characterized by a height H of the bottom of the window. WIN-BOT and the height h of the top of the window WIN-TOP The space 200 may also include a work surface, such as a table 206, which may have a height h WORK and may be located at a distance d from the window 202 WORK Place.

[0063] A motorized window shade, such as a motorized roller blind 220, may be installed on the window 202. The motorized roller blind 220 may include a roller tube 222 around which a shade fabric 224 may be wound. The shade fabric 224 may have a hem 226 at a lower edge of the shade fabric, which may be at a height H above the floor. HEMBAR The motorized roller blind 220 may include a motor drive unit (not shown) that may be configured to rotate the roller tube 222 to move the shade fabric 224 in the fully open position P. OPEN (For example, here, the window 202 is not covered and the bead 226 can be located at the top of the window) and the fully closed position P CLOSED (For example, here, the window 202 is completely covered and the curling edge 226 can be located at the bottom of the window). In addition, the motor drive unit can control the position of the shielding fabric 222 to one of a plurality of preset positions between the fully open position and the fully closed position.

[0064] Glare conditions for occupants of room 200 may be caused by glare sources such as the sun, external lights (e.g., outdoor building lights or street lights), or reflections from the sun or other bright light sources that may be located outside of window 202. For example, light from a glare source may shine into room 200 through window 202 and may extend into the room (e.g., onto the floor) up to a penetration distance d from window 202 and / or from facade 204. PEN The light penetration distance d may be measured in a direction perpendicular to the window 202 and / or from the facade 204. PEN The penetration distance d of light from the glare source PEN The height h of the rolled edge 226 of the motorized roller blind 220 may be HEMBAR and the contour angle θ of the glare source P Function of the contour angle θ P The position of the glare source outside of window 202 may be represented. The position of the glare source may be defined by an altitude angle (e.g., a vertical angle) and an azimuth angle (e.g., a horizontal angle) from the center of view of visible light sensor 210 (e.g., a direction perpendicular to window 202 and / or facade 204). P It can be defined as the angle of the line from the glare source to the visible light sensor projected onto a vertical plane perpendicular to the window 202 and / or the facade 204. The penetration distance d from the glare source to the floor of the space 200 can be determined as follows PEN (e.g., in a direction perpendicular to the window 202 and / or the facade 204): Consider the penetration distance d PEN , the height h of the curling edge 226 HEMBAR And the triangle formed by the length l of the light irradiated into the space 200 in the normal direction of the window 202, such as Figure 2 As shown in the side view of the window 202, for example

[0065] tan(θ P )=h HEMBAR / d PEN (Equation 1)

[0066] In response to visible light sensor 210 detecting a glare source outside of window 202, visible light sensor 210 and / or system controller (e.g., system controller 110) may be configured to determine a position to control shielding fabric 224 of motorized roller shade 220 (e.g., hem 226 of shielding fabric 224) to prevent a glare condition in the space. For example, the position of hem 226 of motorized roller shade 220 may be adjusted to prevent penetration of distance d PEN Exceeding the maximum penetration distance d PEN-MAX For example, if the sun is shining in window 220, visible light sensor 210 may be configured to process the image to determine a profile angle θ defining the location of the glare source.S Visible light sensor 210 and / or system controller may be configured to calculate a desired height h above the floor to which curling edge 226 is to be directed. HEMBAR To prevent the light from the glare source from exceeding the maximum penetration distance d PEN-MAX ,For example,

[0067] h HEMBAR =tan(θ P )·d PEN-MAX (Equation 2)

[0068] Visible light sensor 210 and / or system controller may be configured with the top and bottom heights h of window 220, for example, during configuration of the visible light sensor and / or system controller. WIN-TOP 、h WIN-BOT The visible light sensor 210 and / or the system controller may be configured to use the top and bottom heights h WIN-TOP 、h WIN-BOT and the calculated curling height h HEMBAR Determine the fully open position P of the motorized roller blind 220 OPEN and fully closed position P CLOSED The desired position of the curling edge 226 between.

[0069] In addition, the position of the hem 226 of the motorized roller shade 220 can be adjusted to prevent light from the glare source from shining on the table 206. For example, the visible light sensor 210 and / or the system controller can be configured to calculate the required height h above the floor to which the hem 226 should be controlled to prevent light from the glare source from shining on the table 206. HEMBAR ,For example,

[0070] h HEMBAR =(tan(θ P )·d WORK )+h WORK (Equation 3) The position of the hem 226 of the motorized roller shade 220 can be adjusted to prevent light from the glare source from shining into the eyes of the occupants of the space 200. For example, the visible light sensor 210 and / or the system controller can be configured to calculate a desired height above the floor to which the hem 226 is controlled based on an estimated height of the occupant's eyes and / or an estimated distance of the occupant from the window. HEMBAR For example, if room 200 includes a visible light sensor located within the room (e.g., as Figure 1 If a visible light sensor 180 of the load control system 100 is provided, the visible light sensor can be configured to process an image of the room to determine a value of the occupant's eye height and / or the occupant's distance from the window.

[0071] The visible light sensor 210 and / or the system controller may store the maximum penetration distance d PEN-MAX 、Height h of table 206 WORK and the distance d between the table 206 and the window 202 WORK For example, during configuration of visible light sensor 210 and / or system controller (e.g., using mobile device 190 or other network device), visible light sensor 210 and / or system controller can be configured with these values. Additionally or alternatively, visible light sensor 206 and / or system controller can be configured with a maximum penetration distance d PEN-MAX 、Height of table 206 h WORK and the distance d between the table 206 and the window 202 WORK For example, if room 200 includes a visible light sensor located within the room (e.g., as Figure 1 The visible light sensor 180 of the load control system 100 may be configured to process the room image to determine the maximum penetration distance d PEN-MAX 、Height of table 206 h WORK and the distance d between the table 206 and the window 202 WORK values ​​and transmits these values ​​to the visible light sensor 210 on the window 202 and / or the system controller.

[0072] Figure 3 is a simplified block diagram of an example visible light sensor 300, which may be deployed as Figure 1 One or both of the visible light sensors 180, 182 of the load control system 100 shown in FIG. Figure 2 The visible light sensor 300 may include a control circuit 310, such as a microprocessor, a programmable logic device (PLD), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or any suitable processing device. The control circuit 310 may be coupled to a memory 312 for storing sensor events, masks, operating characteristics, etc. of the visible light sensor 300. The memory 312 may be implemented as an external integrated circuit (IC) or an internal circuit of the control circuit 310.

[0073] The visible light sensor 300 may include a visible light sensing circuit 320 having: an image recording circuit, such as a camera 322; and an image processing circuit, such as a processor 324. The image processor 324 may include a digital signal processor (DSP), a microprocessor, a programmable logic device (PLD), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or any suitable processing device. The camera 322 may be positioned toward a space in which one or more environmental features are to be sensed in the space (e.g., entering the room 102). The camera 322 may be configured to capture or record an image. For example, the camera 322 may be configured to capture images at a specific sampling rate, where a single image may be referred to as a frame acquisition. An example frame acquisition rate is approximately ten frames per second. The frame acquisition rate may be limited to reduce the processing power required by the visible light sensor. Each image may be composed of an array of pixels, where each pixel has one or more values ​​associated therewith. A raw RGB image may have three values ​​for each pixel: one value for each of the red, green, and blue intensities, respectively. One implementation may use the existing RGB system for pixel color, where each component of intensity has a value of 0-255. For example, a red pixel has an RGB value of (255, 0, 0), while a blue pixel has an RGB value of (0, 0, 255). Any given pixel detected as a combination of red, green, and / or blue may be some combination of (0-255, 0-255, 0-255). One will recognize that an over-representation of an image may be used.

[0074] The camera 322 may provide captured images (e.g., raw images) to an image processor 324. The image processor 324 may be configured to process the images and provide one or more sensed signals representative of sensed environmental characteristics (e.g., occurrence of movement, amount of movement, direction of movement, speed of movement, number of occupants counted, light intensity, light color, amount of direct sunlight penetration, etc.) to the control circuit 310. For example, the one or more sensed signals provided to the control circuit 310 may represent movement in the space and / or measured light levels in the space.

[0075] Additionally, the image processor 324 may provide a raw image or a processed (e.g., pre-processed) image to the control circuit 310, which may be configured to process the image to determine the sensed environmental characteristics. Regardless, the control circuit 310 may then use the sensed environmental characteristics to send control commands to the loading device (e.g., directly or through the system controller 110).

[0076] As is known in the art, one example of a processed image is the brightness of a pixel, which can be measured from the image RGB by adding the R, G, B intensity values, weighted according to the following formula:

[0077] Brightness (perceived) = (0.299*R + 0.587*G + 0.114*B) (Formula 4) Example weighting coefficients may take into account the non-uniform response of the human eye to light of different wavelengths. However, other coefficients may be used instead.

[0078] As previously described, if the visible light sensor 300 has a fisheye lens, the image captured by the camera 322 may be distorted. The image processor 324 may be configured to pre-process the image to de-distort the image and generate a non-distorted image.

[0079] Another image processing technique may include mapping the RGB sensor response to CIE tristimulus values ​​to obtain chromaticity coordinates to obtain correlated color temperature (CCT). Joe Smith describes an example method in Intelligent Opto Sensor Designer's Notebook on February 27, 2009: Calculating Color Temperature and Illuminance using the TAOS TCS3414CSDigital Color Sensor. Another example of a processed image may be an image to which a digital filter or digital mask has been applied. A digital mask can be used to eliminate areas within an image that may not have values ​​for further analysis and processing. Alternatively, the complement of the digital mask can be an area of ​​interest (e.g., an area within an image that has been identified for further processing or analysis). A processed image can also be created by a technique called background subtraction. For example, using background subtraction, a background image (e.g., a previous state of a room) that can be incorporated into the history of the image over time can be subtracted from the current image (e.g., the current state of a room). This technique can identify differences in images. Background subtraction can be used to detect movement in an image and for occupancy and vacancy detection. Various algorithms may be used for background maintenance to determine how to effectively combine pixels over time into a background image. Some example background maintenance algorithms may include: adjusted frame differences, mean and threshold, mean and covariance, Gaussian mixtures, and normalized block correlation. These and other similar details inherent to image processing will be familiar to those skilled in the art.

[0080] The control circuit 310 and / or the image processor 324 may be configured to apply one or more masks to focus on one or more regions of interest in an image (e.g., an original image and / or a preprocessed image) to sense one or more environmental features of a space. As used herein, a mask may be any definition of a region of interest that defines an image. For example, assuming that an image may be defined as an NxM array of pixels, wherein each pixel has a defined coordinate / position in the array, a mask is defined as a sequence of pixel coordinates that defines the outer perimeter of a region of interest within the image. As another example, a mask may be defined as an NxM array that corresponds to an NxM array of pixels of an image. For example, each entry of a mask may be 1 or 0, whereby an entry with 1 may define a region of interest. Such a representation may allow an image array and a mask array to be "ANDed", which may cancel or zero all pixels of no interest in the image. As another alternative, a mask may define a region of no interest, rather than a mask defining a region of interest of an image. These are merely examples, and other representations may be used.

[0081] The visible light sensor 300 may include a first communication circuit 330 configured to send and receive digital messages via a first communication link using a first protocol. For example, the first communication link may include a wireless communication link, and the first communication circuit 330 may include an RF transceiver coupled to an antenna. In addition, the first communication link may include a wired digital communication link, and the first communication circuit 330 may include a wired communication circuit. The first protocol may include a proprietary protocol, such as a ClearConnect protocol. The control circuit 310 may be configured to send and receive digital messages via the first communication link during normal operation of the visible light sensor 300. The control circuit 310 may be configured to send an indication of a sensed environmental feature via the first communication link during normal operation of the visible light sensor 300. For example, the control circuit 310 may be configured to send an indication of a detected state (e.g., an occupied or vacant condition) and / or a measured environmental feature (e.g., a measured light level) via the first communication link during normal operation of the visible light sensor 300.

[0082] The visible light sensor 300 may include a second communication circuit 332 configured to send and receive digital messages via a second communication link using a second protocol. For example, the second communication link may include a wireless communication link, and the second communication circuit 332 may include an RF transceiver coupled to an antenna. In addition, the second communication link may include a wired digital communication link, and the second communication circuit 332 may include a wired communication circuit. The second protocol may include a standard protocol, such as a Wi-Fi protocol, a Bluetooth protocol, a Zigbee protocol, etc. The control circuit 310 may be configured to send and receive digital messages via the second communication link during the configuration of the visible light sensor 300. For example, the control circuit 310 may be configured to send an image recorded by the camera 322 via the second communication link during the configuration of the visible light sensor 300.

[0083] Visible light sensor 300 may include power supply 340 for generating a DC power supply voltage Vcc for powering control circuit 310, memory 312, image processor 324, first and second communication circuits 330, 332, and other low voltage circuits of visible light sensor 300. Power supply 340 may include a power supply configured to receive an external power supply voltage from an external power source (e.g., an AC power line voltage power source and / or an external DC power source). In addition, power supply 340 may include a battery for powering the circuits of visible light sensor 300.

[0084] Visible light sensor 300 may also include low power occupancy sensing circuitry, such as passive infrared (PIR) detector circuitry 350. PIR detector circuitry 350 may generate a PIR detection signal V in response to passive infrared energy detected in the space. PIR The PIR detector circuit 350 may consume less power than the visible light sensing circuit 320. However, the visible light sensing circuit 320 may be more accurate than the PIR detector circuit 350. For example, when the power source 340 is a battery, the control circuit 310 may be configured to disable the visible light sensing circuit 320 and use the PIR detector circuit 350 to detect an occupancy condition. The control circuit 310 may, for example, disable the light sensing circuit 320 when the space is vacant. The control circuit 310 may respond to the PIR detection signal V PIR The control circuit 310 can detect an occupancy condition in the space and can subsequently enable the visible light sensing circuit 320 to detect a continuous occupancy condition and / or a vacancy condition. PIR The visible light sensing circuit 320 is enabled immediately after the occupancy condition in the space is detected. PIR), the control circuit 310 may also keep the visible light sensing circuit 320 disabled. The control circuit 310 may keep the visible light sensing circuit 320 disabled until the PIR detection signal V PIR Indicating that the space is vacant. Control circuit 310 may not determine that the space is vacant until visible light sensing circuit 320 subsequently indicates that the space is vacant.

[0085] When the visible light sensor 300 is mounted to a window (e.g., as Figure 1 When the second visible light sensor 182 of the load control system is used, the control circuit 310 can be configured to record one or more images of the space outside the window via the camera 322 and process the one or more images to determine whether a glare condition exists. The visible light sensor 300 may include a fisheye lens (not shown), which may distort the image recorded by the camera 322. The control circuit 310 and / or the image processor 324 may be configured to de-distort the image recorded by the camera 322 to produce a non-distorted image, which may be characterized by lines of constant profile angles.

[0086] The control circuit 310 may be configured to process each pixel of the non-distorted image to determine whether a glare condition exists for each pixel. The control circuit 310 may begin processing the image at a portion of the image relative to the position of the window or window group from which the image was taken. For example, the portion of the image may represent the bottom of the window, and the control circuit may begin processing the non-distorted image at the bottom. The bottom may include a predetermined number of pixel rows from the bottom of the image (e.g., the bottom row of pixels in the non-distorted image). The control circuit may also or alternatively begin processing the image from the top of the image (e.g., the top row of pixels). The portion of the image processed first may depend on the direction in which the motorized window shade moves the covering material to close the covering material and / or the current position of the covering material to reduce processing resources used to identify a glare condition in the image.

[0087] The control circuit 310 may be configured to start with a bottom row of pixels (e.g., on the left or right side) of the non-distorted image. The control circuit 310 may step through each pixel in the bottom row and process each pixel to determine if a glare condition exists before moving forward to the next row. After the control circuit 310 determines that a glare condition exists, the control circuit 310 may stop processing the non-distorted image and may be operable to control one or more motorized window shades (e.g., Figure 1 Motorized curtains 140 and / or Figure 2The motorized roller blinds 220 of the non-distorted image are controlled to remove the glare condition (e.g., as will be described in more detail below). This can prevent the rest of the image from being processed to detect the glare condition. If the control circuit 310 processes the entire image without detecting the glare condition, the control circuit can conclude that there is no glare condition and can control the motorized curtains to open. Since the control circuit 310 processes the pixels of the non-distorted image starting at the bottom row of the non-distorted image, the control circuit 310 can find the lowest pixel indicating the glare source before other higher glare sources are detected. The lowest pixel indicating the glare source is an important parameter for determining the shading position to which the motorized curtains are controlled to prevent glare on the work surface. This allows the control circuit 310 to minimize the amount of processing required to determine the shading control command to prevent glare in the room.

[0088] When processing the non-distorted image to determine whether a glare condition exists, the control circuit 310 can be configured to determine whether an absolute glare condition exists and / or whether a relative glare condition exists (e.g., a contrast glare condition). The control circuit 310 can be configured to determine whether an absolute glare condition exists and / or whether a relative glare condition exists (e.g., a contrast glare condition). The control circuit 310 can be configured to determine whether an absolute light level (e.g., an absolute intensity) of a pixel exceeds an absolute glare threshold (e.g., approximately 10,000 cd / m 2 ), an absolute glare condition is determined to exist. The control circuit 310 can be configured to detect a relative glare condition if the relative light level compared to the background light level (e.g., the difference between the absolute light level of the pixel and the background light level) exceeds a relative glare threshold (e.g., approximately 4,000 cd / m 2 ) then determines that a relative glare condition exists. If the control circuit 310 detects that an absolute glare condition exists or that a relative glare condition exists, the control circuit can stop processing the non-distorted image and move to control one or more motorized window shades to eliminate the glare condition. For example, the one or more motorized window shades can eliminate the glare condition by determining a blocking position based on the location of the glare condition. The threshold value can be adjustable to adjust the sensitivity of the visible light sensor 300. For example, the threshold value can be adjusted by a user during configuration of the visible light sensor 300.

[0089] To determine whether a relative glare condition exists, the control circuit 310 may determine a background light level from a non-distorted image (e.g., a baseline). The background light level may be a value representing the brightness of the background of the non-distorted image. For example, the background light level may be a percentile brightness of the non-distorted image (e.g., 25th percentile luminance). The 25th percentile luminance may be a brightness where 25% of the pixels of the non-distorted image are darker than the 25th percentile luminance.

[0090] When the control circuit 310 has determined that there is a glare condition, the control circuit 310 can process the pixels to determine the contour angle of the glare source. For example, each pixel of the image can be characterized by a value of the contour angle. The value of the contour angle can be stored in the memory 312. The control circuit 310 can retrieve the appropriate contour angle based on the processed pixels. In addition, the contour angle can be determined and / or calculated based on the data of the image. The control circuit 310 can use the contour angle to determine the position to which the motorized curtain is controlled (e.g., as shown in equations 2 and / or 3 above). In addition, the control circuit 310 can transmit the contour angle to another device (e.g., the system controller 110), which can determine the position to which the motorized curtain is controlled to avoid the glare condition in the room.

[0091] Figure 4 4 is a simplified flow chart of an example glare detection process 400. The glare detection process 400 may be periodically performed by a control circuit of a visible light sensor (e.g., control circuit 310 of visible light sensor 300) at 410. At 412, the control circuit may retrieve an image (e.g., a non-distorted image). For example, the control circuit may record one or more images and process the images to produce a non-distorted image. Additionally or alternatively, the control circuit may retrieve one or more images (e.g., a non-distorted image) from a memory at 412. At 414, the control circuit may begin processing a portion of the image. For example, the control circuit may begin processing a bottom portion of the image (e.g., a bottom row of pixels in the image). At 416, the control circuit may process pixels of the image to determine whether a glare condition (e.g., an absolute glare condition and / or a relative glare condition) exists. If the control circuit does not determine at 418 that a glare condition exists and the control circuit does not process the current image at 420, the control circuit may move to the next pixel at 422 and then process the next pixel at 416 to determine whether a glare condition exists. If the control circuit determines at 418 that a glare condition exists, the control circuit may process the current pixel at 424 to allow the motorized window shade to be controlled to prevent the glare condition before the process 400 exits. For example, the control circuit may determine the contour angle of the glare source in the image and / or determine the position to which the motorized window shade is controlled to prevent the glare condition at 424. If the control circuit does not detect a glare condition before the control circuit completes processing the image at 420, the process 400 may exit. Although the image processing may be described as being performed at the visible light sensor, the image processing may be performed at a system controller or another image processing device in the load control system.

[0092] Figure 5AA flow chart of an example glare detection process 500 is shown that is periodically performed by a control circuit of a visible light sensor (e.g., control circuit 210 of visible light sensor 200) at 510. At 512, the control circuit may retrieve an image. For example, the image may include a high dynamic range (HDR) image that may be a composite of multiple low dynamic range (LDR) images (e.g., six LDR images) recorded by a camera of the visible light sensor. At 514, the control circuit may de-warp the retrieved image (e.g., if the visible light sensor has a fisheye lens) to produce a non-distorted image. For example, to produce the non-distorted image, the control circuit may generate lines of constant contour angles from the distorted image. At 516, the control circuit may determine the background brightness of the non-distorted image. For example, the control circuit may calculate percentile brightness (e.g., the 25th percentile brightness L 25 ), which can be a value representing the brightness of the background (e.g., baseline) of the non-distorted image.

[0093] At 518, the control circuit may determine the brightness L of the i-th pixel of the non-distorted image (from 514) PI For example, the control circuit may start at one of the pixels on the bottom row of the non-distorted image (e.g., on the left or right side of the bottom row) when performing 518 for the first time. If the retrieved image is an HDR image, the control circuit may retrieve the brightness L of the i-th pixel from the data of the HDR image at 518. PI The control circuit can also calculate the brightness L of the i-th pixel at 518. PI (For example, using equation 4 shown above).

[0094] If the brightness L calculated at 520 PI Greater than the high brightness threshold L TH-HI (For example, about 10,000 cd / m 2 ), the control circuitry may determine at 522 that a glare condition (eg, an absolute glare condition) exists. At 524, the control circuitry may use the row of the i-th pixel from the non-distorted image to determine the contour angle A of the i-th pixel. PI (For example, indicating the approximate location of the glare source). For example, the control circuit can call the contour angle A of the i-th pixel from the memory. PI And / or the contour angle A can be calculated using the data of the i-th pixel and / or other pixels of the image PI .

[0095] At 526, the control circuit may determine the contour angle A based on the contour angle A. PIDetermine a shielding position for preventing light from a glare source from exceeding a maximum penetration distance and / or for preventing glare on a work surface (e.g., using Equation 2 and / or Equation 3 as shown above). The shielding position for preventing light from a glare source from exceeding a maximum penetration distance and / or for preventing glare on a work surface may also depend on the maximum penetration distance, the height of the work surface, and / or the distance of the work surface from the window, which may be stored in a memory. At 528, the control circuit may send a shielding control command for controlling the position of a motorized window shade in the space to a determined shielding position for preventing glare on the work surface (e.g., directly or via the system controller 110), and the glare detection process 500 then exits. Alternatively, the control circuit may be configured to set the profile angle A to the maximum penetration distance. PI The image processing may be described as being performed at the visible light sensor, but may be performed at the system controller or another image processing device in the load control system.

[0096] If the brightness L calculated at 520 PI Not greater than the high brightness threshold L TH-HI , the control circuit can be configured to determine the calculated brightness L PI Is it less than the low brightness threshold L? TH-LO (For example, about 4,000 cd / m 2 ). If the brightness L calculated at 530 PI Less than the low brightness threshold L TH-LO , the control circuit may decide not to process the i-th pixel of the non-distorted image. If the control circuit does not process the pixel of the non-distorted image at 532, the control circuit may move to the next pixel (e.g., i=i+1) at 534, and may calculate the brightness L of the next pixel of the non-distorted image at 518. PI As previously described, the control circuitry may start at one of the pixels on the bottom row of the non-distorted image (e.g., to the left or right of the bottom row). When the control circuitry moves to the next pixel at 534, the control circuitry may move to a pixel in the current row of pixels that is adjacent to the previous pixel (e.g., to the left or right of the previous pixel). When the control circuitry calculates the brightness of each pixel in a row, the control circuitry may move forward to the next row of pixels. In this manner, the control circuitry may step through multiple pixels in the non-distorted image by starting at the bottom row and moving forward through the rows of the image.

[0097] If the brightness L calculated at 530 PI Not less than the low brightness threshold L TH-LO , the control circuit can be based on the calculated brightness L at 536PI and the 25th percentile brightness L 25 Calculate the contrast C PI (For example, C PI =L PI / L 25 ). If the contrast C PI At 538, it is greater than the contrast threshold C TH (e.g., about 15), the control circuit may determine at 522 that a glare condition (e.g., a relative glare condition) exists. The control circuit may then calculate at 524 the contour angle A of the i-th pixel. PI , based on the contour angle A at 526 PI The shading position for preventing glare on the work surface is determined, and a shading control command for controlling the position of the motorized window shade in the space is sent at 528, and the glare detection process 500 then exits. Alternatively, the control circuit may use the calculated brightness L of the i-th pixel at 538 PI and the brightness of the adjacent pixels (eg, the lowest brightness of the adjacent pixels) to calculate the contrast C at 536 PI For example, the neighboring pixels may be those pixels having a certain number of pixels from the i-th pixel (eg, all pixels within 5 pixels from the i-th pixel).

[0098] When the control circuitry completes processing the pixels of the non-distorted image at 532 without determining that a glare condition exists, the control circuitry may determine that a glare condition does not exist at 540 and may send a block control command for controlling the position of the motorized window covering at 528, and the glare detection process 500 exits. For example, if a glare condition does not exist, the control circuitry may send a block command for opening the motorized window covering (e.g., to a fully open position or a visor position).

[0099] Figure 5B A flow chart of another example glare detection process 550 is shown that is periodically performed by a control circuit of a visible light sensor (e.g., control circuit 210 of visible light sensor 200) at 560. At 562, the control circuit may retrieve an image (e.g., an HDR image). At 564, the control circuit may de-distort the retrieved image (e.g., if the visible light sensor has a fisheye lens) to produce a non-distorted image (e.g., by generating lines of constant profile angle from the distorted image). At 566, the control circuit may determine a background brightness L of the non-distorted image. BG For example, the control circuit can calculate the percentile brightness (e.g., the 25th percentile brightness L 25 ), which can be a value representing the brightness of the background (e.g., baseline) of the non-distorted image.

[0100] At 568, the control circuit can determine the contrast brightness LC , which may represent the brightness of a glare source that may produce a contrast glare condition (eg, a relative glare condition). For example, the control circuit may be configured to set the background brightness L BG Scaling contrast threshold C TH (e.g., about 15) to generate a contrast brightness L C , for example, L C =C TH ·L BG If the contrast brightness L at 570 C Greater than the low brightness threshold L TH-LO (For example, about 4,000 cd / m 2 ) and is less than the high brightness threshold L TH-HI (For example, about 10,000 cd / m 2 ), the control circuit can set the brightness threshold L at 572 TH Set to be equal to the contrast brightness L C Otherwise, the control circuit may set the brightness threshold L at 574. TH Set equal to the high brightness threshold L TH-HI .

[0101] At 576, the control circuit may determine (from 564) the brightness L of the i-th pixel of the non-distorted image. PI (For example, by retrieving the brightness L from the data of the HDR image PI and / or calculate the brightness L PI ). For example, the control circuit may start at one of the pixels on the bottom row of the non-distorted image (e.g., to the left or right of the bottom row) when performing 576 for the first time. At 578, if the calculated brightness L PI Greater than the brightness threshold L TH , the control circuit may determine at 580 that a glare condition exists. At 582, the control circuit may use the row of the i-th pixel from the non-distorted image to calculate the contour angle A of the i-th pixel. PI (e.g., indicating the approximate location of the glare source). At 584, the control circuit may determine the position of the glare source based on the profile angle A. PIDetermine a shielding position for preventing light from a glare source from exceeding a maximum penetration distance and / or for preventing glare on a work surface (e.g., using Equation 2 and / or Equation 3 as shown above). The shielding position for preventing light from a glare source from exceeding a maximum penetration distance and / or for preventing glare on a work surface may depend on the maximum penetration distance, the height of the work surface, and / or the distance of the work surface from the window, which may be stored in a memory. At 586, the control circuitry may send a shielding control command for controlling the position of a motorized window shade in the space to the determined shielding position for preventing glare on the work surface (e.g., directly or via the system controller 110), and the glare detection process 550 exits. Alternatively, the control circuitry may be configured to set the profile angle A to the maximum penetration distance. PI The image processing may be described as being performed at the visible light sensor, but may be performed at the system controller or another image processing device in the load control system.

[0102] If the control circuit has not processed a pixel of the non-distorted image at 588, the control circuit may move to the next pixel (eg, i=i+1) at 590 and may calculate the brightness L of the next pixel at 576. PI As previously described, the control circuitry may start with one of the pixels on the bottom row of the non-distorted image (e.g., to the left or right of the bottom row). When the control circuitry moves to the next pixel at 590, the control circuitry may move to a pixel in the current row of pixels that is adjacent to the previous pixel (e.g., to the left or right of the previous pixel). When the control circuitry calculates the brightness of each pixel in a row, the control circuitry may move forward to the next row of pixels. In this manner, the control circuitry may step through multiple pixels in the non-distorted image by starting at the bottom row and moving forward through the rows of the image.

[0103] When the control circuitry completes processing the pixels of the non-distorted image at 588 without determining that a glare condition exists, the control circuitry may determine that a glare condition does not exist at 592 and may send a block control command for controlling the position of the motorized window covering at 586, and the glare detection process 550 exits. For example, if a glare condition does not exist, the control circuitry may send a block command for opening the motorized window covering (e.g., to a fully open position or a visor position).

[0104] Figure 66 is a simplified flow chart of background brightness process 600. Background brightness process 600 may determine a value representing the brightness of the background of an image (e.g., a non-distorted image). Background brightness process 600 may be performed at 610 by control circuitry of a visible light sensor (e.g., control circuitry 310 of visible light sensor 300), a system controller, or other image processing device. For example, background brightness process 600 may be performed at Figure 5A 516 of the glare detection process 500 shown in FIG. 5 and / or Figure 5B The glare detection process 550 shown in FIG. 5 is executed at 566 to calculate the 25th percentile brightness L of the non-distorted image. 25 At 612, the control circuitry may reorder the pixels of the image in order from darkest to lightest. At 614, the control circuitry may find a predetermined percentage (e.g., approximately 25%) of pixels on the way from the darkest pixel to the lightest pixel. For example, if the image has a total number of Np pixels, the control circuitry may count the reordered pixels (from darkest to lightest) until a number N is found. 25 pixels, where N 25 =0.25·N P At 616, the control circuit may calculate the brightness of the pixel (eg, using pixel number N). 25 The color of the pixel at the position of the pixel) to determine the 25th percentile brightness L 25 Alternatively, the control circuit may calculate the brightness of a different numbered pixel to set as the brightness of the background. The background brightness process 600 may exit at 618.

[0105] Although described herein by controlling the circuit processing to process the non-distorted image starting from the bottom (eg, the bottom row) and processing the rows of the image upwards, Figure 4 5, the process can be reversed when the room 102 includes a motorized window shade that is a bottom-up window shade, e.g., the window shade fabric moves from the bottom of the window to the top of the window to cover the window. For example, when the motorized window shade is a bottom-up window shade, the glare detection process 400, 500 can process the image starting from the top (e.g., the top row) and process the rows of the image downward, e.g., until a glare source is detected.

[0106] Fig. 7A 700 is a sequence diagram of an example anti-glare process. Fig. 7AAs shown, the anti-glare process 700 can be performed by a visible light sensor 702 (e.g., visible light sensors 182, 300) and a motorized window shade 704 (e.g., motorized roller shade 220). At 710, the visible light sensor 702 can record an image of the exterior of a room and / or building. At 712, the visible light sensor can process the image to detect a glare condition. For example, the detection of a glare condition can include calculating the brightness L of a pixel in the image. PI and compare them with brightness thresholds (e.g. Figure 5A 520, 522, 530, 536 and / or 538) for comparison.

[0107] If a glare condition is detected, visible light sensor 702 can determine a profile angle of the glare condition at 714. As described herein, a profile angle can define the angle of the glare source at a window (e.g., Figure 2 The silhouette angle may be determined based on the position of the detected glare source (e.g., a pixel in the image recorded at 710). Visible light sensor 702 may include a lookup table to determine the silhouette angle. For example, the lookup table may provide an indication of the silhouette angle based on the position of the detected glare source (e.g., a pixel in the image recorded at 710).

[0108] At 716, visible light sensor 702 can determine a blocking position of motorized window covering 704. The blocking position can prevent glare conditions from affecting a room (e.g., room 102 and / or space 200). For example, a blocking fabric can be positioned so that the blocking fabric blocks light from a glare source represented by a pixel in which glare is detected. At 718, the blocking position can be transmitted to motorized window covering 704. After receiving the blocking position, the motorized window covering can move the blocking fabric to the indicated position at 720.

[0109] Figure 7B is a sequence diagram of an example anti-glare process 750. Figure 7B As shown, the anti-glare process 750 can be performed by a visible light sensor 752 (e.g., visible light sensor 182, 300), a system controller 754 (e.g., system controller 110), and a motorized window shade 756 (e.g., motorized roller shade 220). At 758, the visible light sensor 752 can record an image of the room and / or building exterior. At 760, the visible light sensor can process the image to detect a glare condition. For example, the detection of a glare condition can include calculating the brightness L of a pixel in the image. PI and compare them with brightness thresholds (e.g. Figure 5A 520, 522, 530, 536 and / or 538) for comparison.

[0110] If a glare condition is detected, visible light sensor 752 may determine a profile angle of the glare condition at 762. As described herein, a profile angle may define the angle of the glare source at a window (e.g., Figure 2 The silhouette angle may be determined based on the position of the detected glare source (e.g., a pixel in the image recorded at 758). Visible light sensor 752 may include a lookup table to determine the silhouette angle. For example, the lookup table may provide an indication of the silhouette angle based on the position of the detected glare source (e.g., a pixel in the image recorded at 758).

[0111] At 764, visible light sensor 752 may send the profile angle to system controller 754 (e.g., system controller 110). At 766, system controller 754 may determine a blocking position for motorized window covering 756. For example, a blocking fabric may be positioned such that the blocking fabric blocks light from a glare source represented by a pixel in which glare is detected. At 768, system controller 754 may send the blocking position to motorized window covering 756. After receiving the blocking position, the motorized window covering may move the blocking fabric to the indicated position at 770. Although visible light sensor 752 is shown as processing an image, system controller 754 may also or alternatively perform image processing after visible light sensor 752 generates an image.

[0112] Figure 8 is a simplified example of a non-distorted image 800 for detecting a glare condition. Figure 8 As shown, image 800 may include one or more pixels (e.g., pixels 802, 804, and 806). The pixels may be organized in one or more pixel rows and / or one or more pixel columns. A visible light sensor (e.g., visible light sensor 300) may retrieve image 800 and process the image to determine whether a glare condition exists. The visible light sensor may process the image to determine whether a glare condition exists. The determination may include determining whether an absolute glare condition exists and / or whether a relative glare condition exists.

[0113] The visible light sensor may begin processing the first pixel in the bottom of image 800. For example, the visible light sensor may begin processing image 800 at pixel 802. The visible light sensor may determine the brightness of pixel 802 to determine whether an absolute glare condition and / or a relative glare condition exists. If the visible light sensor determines that a glare condition (e.g., an absolute glare condition and / or a relative glare condition) does not exist, the visible light sensor may process the next pixel in the image (e.g., pixel 804).

[0114] The visible light sensor may continue to process pixels in the image until the visible light sensor determines that a glare condition exists or finishes processing the image. For example, the visible light sensor may determine that a relative glare condition or an absolute glare condition exists at pixel 806 (e.g., the brightness of pixel 806 is above a high brightness threshold or a relative brightness threshold) and stop processing the image at pixel 806.

[0115] Fig. 9 is a block diagram illustrating an example system controller 900, such as the system controller 110 described herein. The system controller 900 may include a control circuit 902 for controlling the functions of the system controller 900. The control circuit 902 may include one or more general purpose processors, special purpose processors, conventional processors, digital signal processors (DSPs), microprocessors, integrated circuits, programmable logic devices (PLDs), or application specific integrated circuits (ASICs), etc. The control circuit 902 may perform signal encoding, data processing, image processing, power control, input / output processing, or any other function that enables the system controller 900 to perform as described herein. The control circuit 902 may store information in and / or retrieve information from a memory 904. The memory 904 may include non-removable memory and / or removable memory. The non-removable memory may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of non-removable memory storage. The removable memory may include a subscriber identity module (SIM) card, a memory stick, a memory card, or any other type of removable memory.

[0116] The system controller 900 may include a communication circuit 906 for sending and / or receiving information. The communication circuit 906 may perform wireless and / or wired communications. The system controller 900 may also or alternatively include a communication circuit 908 for sending and / or receiving information. The communication circuit 906 may perform wireless and / or wired communications. The communication circuits 906 and 908 may communicate with the control circuit 902. The communication circuits 906 and 908 may include an RF transceiver or other communication module capable of performing wireless communications via an antenna. The communication circuit 906 and the communication circuit 908 may be capable of performing communications via the same communication channel or different communication channels. For example, the communication circuit 906 may be capable of communicating via a wireless communication channel (e.g., Near Field Communication (NFC), cellular, etc.) (e.g., with a network device, through a network, etc.), and the communication circuit 908 may be able to communicate via another wireless communication channel (e.g., or proprietary communication channels such as CLEARCONNECT TM ) (communication with control devices and / or other devices in a load control system).

[0117] The control circuit 902 can communicate with an LED indicator 912 to provide an indication to the user. The control circuit 902 can communicate with an actuator 914 (e.g., one or more buttons) that can be actuated by the user to communicate the user selection to the control circuit 902. For example, the actuator 914 can be actuated to place the control circuit 902 in an association mode and / or to communicate an association message from the system controller 900.

[0118] Each module in the system controller 900 may be powered by a power supply 910. The power supply 910 may include, for example, an AC power supply or a DC power supply. The power supply 910 may generate a power supply voltage Vcc for powering the modules in the system controller 900.

[0119] Fig.10 1 is a block diagram illustrating an example control target device (e.g., load control device 1000) as described herein. Load control device 1000 may be a dimmer switch, an electronic switch, an electronic ballast for a lamp, an LED driver for an LED light source, an AC plug-in load control device, a temperature control device (e.g., a thermostat), a motor drive unit for a motorized curtain, or other load control device. Load control device 1000 may include communication circuit 1002. Communication circuit 1002 may include a receiver, an RF transceiver, or other communication module capable of performing wired and / or wireless communication via communication link 1010. Communication circuit 1002 may communicate with control circuit 1004. Control circuit 1004 may include one or more general purpose processors, special purpose processors, conventional processors, digital signal processors (DSPs), microprocessors, integrated circuits, programmable logic devices (PLDs), or application specific integrated circuits (ASICs), etc. Control circuit 1004 may perform signal encoding, data processing, power control, input / output processing, or any other function that enables load control device 1000 to perform as described herein.

[0120] The control circuit 1004 may store information in and / or retrieve information from the memory 1006. For example, the memory 1006 may store a registry of related control devices and / or control instructions. The memory 1006 may include a non-removable memory and / or a removable memory. The load control circuit 1008 may receive instructions from the control circuit 1004 and may control the electrical load 1016 based on the received instructions. For example, the electrical load 1016 may control a motorized curtain (e.g., the motorized curtain 150). The load control circuit 1008 may send status feedback about the status of the electrical load 1016 to the control circuit 1004. The load control circuit 1008 may receive power via the hot connection 1012 and the neutral connection 1014 and may provide an amount of power to the electrical load 1016. The electrical load 1016 may include any type of electrical load.

[0121] The control circuit 1004 can communicate with an actuator 1018 (e.g., one or more buttons), which can be actuated by a user to transmit a user selection to the control circuit 1004. For example, the actuator 1018 can be actuated to place the control circuit 1004 in an association mode and / or transmit an association message from the load control device 1000.

[0122] Although features and elements are described herein in specific combinations, each feature or element may be used alone or in any combination with other features and elements. For example, the functions described herein may be described as being performed by a control device such as a remote control device or a lighting device, but may be similarly performed by a hub device or a network device. The methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium to be executed by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), removable disks, and optical media such as CD-ROM disks and digital versatile disks (DVDs).

[0123] Although the methods described herein are described with reference to controlling motorized window shades (e.g., motorized window shades 150 and / or motorized roller shades 220) to prevent glare conditions, the methods may be used to control other types of control devices to prevent and / or mitigate glare conditions. For example, the methods described herein may be used to control the transmittance of controllable electrochromic glass and / or adjust the position of indoor or outdoor controllable blinds to prevent and / or mitigate glare conditions.

Claims

1. A method for detecting the position of a glare source in order to control the positioning of a motorized window shade, the method comprising: obtaining an image of a view exterior of the window in which the motorized window covering is installed; identifying at least a first portion of the image to be processed to detect a location of a glare source; initiating processing of at least a first portion of the image to detect a glare condition in the image indicative of the location of the glare source; detecting the glare condition in the at least one first portion of the image based on a brightness value in the at least one first portion of the image; preventing processing of at least a second portion of the image to preserve processing resources; identifying the location of the glare source based on the glare condition detected in the at least one first portion of the image; as well as Based on the identified location of the glare source, the positioning of the motorized window shade is controlled to block the glare source.

2. The method according to claim 1, wherein: The at least one first portion comprises a bottom portion of the image, and wherein the at least one second portion of the image comprises a top portion of the image.

3. The method according to claim 2, wherein: The image comprises rows of pixels, and wherein starting processing the at least one first portion of the image comprises: Starting at the first pixel on the first row of pixels of the image, and Stepping through each of the plurality of pixels on the first row until the glare condition is detected before continuing to the next row of pixels, wherein processing of the image is stopped when the glare source is detected to avoid processing remaining unprocessed pixels of the image.

4. The method according to claim 3, wherein: Processing the row of pixels further includes calculating a respective brightness of each of the plurality of pixels, wherein a location of the glare condition is detected based on a respective brightness value of at least one pixel in the at least one first portion of the image.

5. The method according to claim 3, wherein: The location of the glare source is identified responsive to the location of a particular pixel in the image.

6. The method according to claim 2, wherein: The positioning of the motorized window covering is controlled by sending control commands configured to control the positioning of the motorized window covering. 7 . The method of claim 2 , further comprising identifying the location of the glare source when a value of a particular pixel is greater than a threshold value.

8. The method according to claim 2, further comprising: calculating a profile angle of the glare source in response to the determined position of the glare source in the image; as well as The position to which the motorized window covering is controlled is determined in response to the profile angle.

9. A device configured to detect the location of a glare source in order to control the positioning of a motorized window shade, the device comprising: A control circuit, the control circuit being configured to: obtaining an image of a view exterior of the window in which the motorized window covering is installed; identifying at least a first portion of the image to be processed to detect a location of a glare source; initiating processing of at least a first portion of the image to detect a glare condition in the image indicative of the location of the glare source; detecting the glare condition in the at least one first portion of the image based on a brightness value in the at least one first portion of the image; preventing processing of at least a second portion of the image to preserve processing resources; identifying the location of the glare source based on the glare condition detected in the at least one first portion of the image; as well as Based on the identified location of the glare source, the positioning of the motorized window shade is controlled to block the glare source.

10. The device according to claim 9, wherein: The at least one first portion comprises a bottom portion of the image, and wherein the at least one second portion of the image comprises a top portion of the image.

11. The device according to claim 10, wherein: The image comprises rows of pixels, and wherein the control circuit is configured to begin processing the at least one first portion of the image further comprises the control circuit being configured to: Starting at a first pixel on a first row of pixels of the image; and stepping through each of the plurality of pixels on the first row until the glare condition is detected before continuing to the next row of pixels; and Processing of the image is stopped when the glare source is detected to avoid processing remaining unprocessed pixels of the image.

12. The device according to claim 11, wherein The control circuit being configured to process the row of pixels further comprises the control circuit being configured to calculate a corresponding brightness of each of the plurality of pixels, wherein the position of the glare source is detected based on a corresponding brightness value of at least one pixel in the at least one first portion of the image.

13. The device according to claim 11, wherein: The control circuit is configured to detect the position of the glare source in response to a position of a particular pixel in the image.

14. The device of claim 10, further comprising a communication circuit, wherein: The control circuit being configured to control the positioning of the motorized window covering further includes the control circuit being configured to send, via the communication circuit, control commands configured to control the positioning of the motorized window covering.

15. The apparatus according to claim 10, wherein: The control circuit is configured to identify the location of the glare source when a value of a specific pixel is greater than a threshold value.

16. The apparatus according to claim 10, wherein: The control circuit is configured to: calculating a profile angle of the glare source in response to the determined position of the glare source in the image; and The position to which the motorized window covering is controlled is determined in response to the profile angle.

17. A computer readable medium having stored thereon computer executable instructions which, when executed by a control circuit, cause the control circuit to: obtaining an image of a view exterior of the window in which the motorized window covering is installed; identifying at least a first portion of the image to be processed to detect a location of a glare source; initiating processing of at least a first portion of the image to detect a glare condition in the image indicative of the location of the glare source; detecting the glare condition in the at least one first portion of the image based on a brightness value in the at least one first portion of the image; preventing processing of at least a second portion of the image to preserve processing resources; identifying the location of the glare source based on the glare condition detected in the at least one first portion of the image; as well as Based on the identified location of the glare source, the positioning of the motorized window shade is controlled to block the glare source.

18. The computer-readable medium of claim 17, wherein: The at least one first portion comprises a bottom portion of the image, and wherein the at least one second portion of the image comprises a top portion of the image.

19. The computer-readable medium of claim 18, wherein: The image comprises rows of pixels, and wherein the computer executable instructions cause the control circuit to process the at least one first portion of the image comprises the computer executable instructions causing the control circuit to: Starting at a first pixel on a first row of pixels of the image; stepping through each of the plurality of pixels on the first row until the glare condition is detected before continuing to the next row of pixels; and Processing of the image is stopped when the glare source is detected to avoid processing remaining unprocessed pixels of the image.

20. The computer-readable medium of claim 19, wherein: The computer executable instructions causing the control circuit to process the row of pixels further include the computer executable instructions causing the control circuit to calculate a respective brightness of each of the plurality of pixels.

21. The computer-readable medium of claim 19, wherein: The computer executable instructions cause the control circuit to identify the location of the glare source in response to the location of a particular pixel in the image.

22. The computer-readable medium of claim 18, wherein: The computer-executable instructions cause the control circuit to control the positioning of the motorized window covering by sending control commands configured to control the positioning of the motorized window covering via the communication circuit.

23. The computer-readable medium of claim 18, wherein: The computer executable instructions cause the control circuit to: identify the position of the glare source when the value of a specific pixel is greater than a threshold value.

24. The computer-readable medium of claim 18, wherein: The computer executable instructions cause the control circuit to: calculating a profile angle of the glare source in response to the determined position of the glare source in the image; and The position to which the motorized window covering is controlled is determined in response to the profile angle.

25. An apparatus for detecting the location of a glare condition and controlling the positioning of a motorized window shade based on the location of the glare condition, the apparatus comprising: A control circuit, the control circuit being configured to: obtaining an image of a view exterior of the window in which the motorized window covering is installed; reordering pixels of the image, wherein the pixels of the image are reordered from the darkest pixel in the image to the lightest pixel in the image; calculating a brightness of a first pixel, the brightness being a predetermined percentage of a distance from the darkest pixel to the brightest pixel; setting a background brightness of the image to the calculated brightness of the first pixel, wherein the background brightness is a value based on which the glare condition is detected in order to control the positioning of the motorized window covering; and The location of the glare condition is detected when a ratio of the brightness of the second pixel to the background brightness is greater than a predetermined contrast threshold.

26. The apparatus of claim 25, wherein: The predetermined percentage is 25%.

27. A load control system, comprising: a plurality of lighting control devices, wherein each lighting control device is configured to control a corresponding lighting load of the plurality of lighting loads; a system controller; and a visible light sensor configured to operate in a plurality of sensor modes, wherein a first sensor mode comprises an occupancy sensor mode configured to detect an occupancy condition and send a first digital message to the system controller, and wherein a second sensor mode comprises a daylight sensor mode configured to detect a lighting intensity of light emitted by the plurality of lighting loads and send a second digital message to the system controller, Wherein, the system controller is configured as: turning the plurality of lighting loads on and off in response to the first digital message; receiving the lighting intensity of the light emitted by the plurality of lighting loads measured by the visible light sensor and sent in the second digital message when the lighting loads are turned on; determining a degradation in light output of the lighting load; and At least one message is sent to the plurality of lighting control devices configured to control the lighting intensity of the lighting loads to compensate for the determined degradation.

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