TWI754749B - System and method for horticultural lighting - Google Patents

Abstract

A method and apparatus are described herein for capturing images of plants using a broad spectrum camera while illuminating the plants with specific light wavelengths from light sources such as light emitting diodes (LEDs). A first light source may be activated, wherein the first light source emits light having a first spectrum toward a bed of a plurality of plants. On a condition that the first light source is activated, a first image of the bed of the plurality of plants may be captured with a broad spectrum camera. A second light source may be activated, wherein the second light source emits light having a second spectrum toward the bed of the plurality of plants. On a condition that the second light source is activated, a second image of the bed of the plurality of plants may be captured with the broad spectrum camera.

Description

System and method for horticultural lighting

The present invention relates to the field of horticultural lighting applications using light emitting diode (LED) light sources.

Semiconductor light emitting devices, including but not limited to light emitting diodes (LEDs), resonant cavity light emitting diodes (RCLEDs), vertical cavity laser diodes (VCSELs) and edge emitting lasers, are the most efficient available one of the light sources. Materials systems used in the fabrication of high brightness light emitting devices capable of operating across the visible spectrum include III-V semiconductors. Blue light emitting LEDs can be formed from binary, ternary, and quaternary alloys of gallium, aluminum, indium, and nitrogen (also known as Group III-nitride materials). Red-emitting LEDs can be formed from binary, ternary, and quaternary alloys of gallium, aluminum, indium, arsenic, and phosphorous.

It can be deposited by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy ( MBE) or other epitaxial techniques to epitaxially grow a stack of semiconductor layers of different compositions and dopant concentrations to fabricate light-emitting devices. The stack of semiconductor layers may include one or more n-type layers doped with, for example, Si, formed over the substrate, one or more light-emitting layers in an active region formed over the n-type layer(s), and One or more p-type layers formed over the active region are doped with eg Mg. Electrical contacts can be formed on the n-type and p-type regions.

Described herein is a method and apparatus for capturing images of plants using a broad-spectrum camera while illuminating plants with specific wavelengths of light from a light source such as an LED. A first light source can be activated, wherein the first light source emits light having a first spectrum toward a planting bed of the plurality of plants. Under a condition that the first light source is activated, a broad-spectrum camera can be used to capture a first image of the planting bed of the plurality of plants. A second light source can be activated, wherein the second light source emits light having a second spectrum toward the planting bed of the plurality of plants. Under a condition that the second light source is activated, a second image of the planting bed of the plurality of plants can be captured using the broad-spectrum camera. The images captured by the broad-spectrum camera can be stored in a memory device and transmitted to a network via a communication interface.

The occupancy of the environment of the planting bed of the plurality of plants can also be detected. Occupancy can be detected via a sensor, for example, by detecting motion in positions of the plurality of plants near the planting bed. Under a condition that no occupancy is detected, a first light source can be activated. The first light source can emit light from a blue-emitting LED and a red-emitting LED toward a planting bed of the plurality of plants. Under a condition that occupancy is detected, a second light source can be activated. The second light source may emit light from a white light-emitting LED toward the planting bed of the plurality of plants. The sensor can also receive wireless communication signals to activate the light source and generate data associated with the planting bed of the plurality of plants and transmit the data to a network.

Embodiments described herein relate to systems and methods that can be used in horticultural applications.

The absorption of light by chlorophyll in plants is one of the key components of photosynthesis. Chlorophyll absorbs light in the red and blue wavelength ranges of the visible spectrum. A large amount of green light incident on plants is not absorbed and is reflected.

FIG. 1 is a graph 100 of photosynthetic efficiency (in arbitrary units) as a function of wavelength (in nanometers). As shown in FIG. 1, the photosynthetic efficiency of plants is highest in the wavelength range between 600 nm and 700 nm (including a wavelength range of red light). Photosynthetic efficiency is also high between 400 nm and 450 nm (including a wavelength range of blue light). The photosynthetic efficiency is relatively low between 450 nm and 600 nm (a wavelength range including green and yellow light). Therefore, horticultural lighting devices are designed to emit more red and blue light than green light compared to lighting devices used for other applications such as lighting and backlighting.

FIG. 2 illustrates an example of a suitable spectrum for a horticultural lighting device 200. Figure 2 is a graph of intensity (in arbitrary units) as a function of wavelength (in nanometers). The illumination device depicted in Figure 2 emits light between 400 nm and 450 nm at high intensity (blue light) and between 600 nm and 700 nm (red light) at high intensity. Although the device shown in Figure 2 emits less yellow or green light, in some embodiments it may emit more yellow or green light, or no yellow or green light at all. In some embodiments, ultraviolet or infrared light and/or yellow, green, orange, or any other color light may be part of the spectrum emitted by a horticultural lighting device.

As used herein, in the embodiments described herein, horticultural lighting or a horticultural light source may refer to, for example, blue light (eg, blue light (eg, 450 nm to 600 nm) that can emit a higher intensity than green-yellow light (eg, 450 nm to 600 nm). A device or devices that emit light of 400 nm to 450 nm light); light that emits red light (for example, 600 nm to 700 nm light) with an intensity higher than that of green-yellow light (for example, 450 nm to 600 nm light) A device or devices; or light that emits blue light and red light (e.g., 400 nm to 450 nm and 600 nm to 700 nm light) with an intensity higher than green-yellow light (e.g., 450 nm to 600 nm) one device or several devices. The horticultural light sources used in the various embodiments described herein can also emit white light.

The area under a graph of the intensity as a function of wavelengths between 400 nm and 450 nm may be larger than the area under the graph between 450 nm and 600 nm; the area under the graph between 600 nm and 700 nm Can be larger than the area under the graph between 450 nm and 600 nm; or the area under the graph between 400 nm and 450 nm and between 600 nm and 700 nm can be larger than the graph between 450 nm and 600 nm area below. For example, horticultural lighting may refer to a device that emits light having a peak wavelength in the range of 400 nm to 450 nm that has an intensity greater than a peak wavelength in the range of 450 nm to 600 nm or Devices, or a device or devices emitting light having a peak wavelength in the range of 600 nm to 700 nm which has an intensity greater than a peak wavelength in the range of 450 nm to 600 nm.

Plant health can be assessed by visual inspection. A spectrogram can reveal details about the inner workings of plants. The relative absorption of wavelengths of light can infer the presence or activity of specific chlorophyll, carotenoids and other light absorbing molecules. Normal vision (ie, the three primary colors or red, green, blue (RGB)) has limited diagnostic value due to its inability to distinguish absolute colors in a spectrogram manner. The human eye cannot distinguish a solid color, such as yellow, from a combination of red and green that triggers the same visual experience. RGB cameras designed to mimic the human eye also suffer from this deficiency. Therefore, plant health is typically observed via multispectral cameras that use multiple filters to selectively image each wavelength of light. These multispectral cameras are complex, expensive and slow. Crop imaging is usually performed in the air or by satellite. Indoor plant monitoring is difficult due to the expense of cameras and the difficulty of shooting from above. Both problems can be overcome by placing a monochromatic camera within the lighting fixture and selectively illuminating the plant bed using multispectral illumination.

In embodiments described herein, a horticultural light source may be activated in response to a detected state change in the environment of the plant; the horticultural light source may be activated in response to a detected occupancy in the environment of the plant; and the plant may be retrieved The image of the horticultural light source can be activated to observe the health of the plant. For illustrative purposes, the embodiments described herein use LEDs as horticultural lighting sources, although other lighting sources may be used.

FIG. 3 is a diagram of an exemplary horticultural lighting system 300 . Horticultural lighting system 300 may include a horticultural light source, such as at least one LED of a plurality of LEDs. The exemplary system of FIG. 3 includes LEDs 14 , 16 and 18 . However, the horticultural lighting system 300 may use any number of LEDs. In an exemplary embodiment, LED 14 may be a blue-emitting LED, LED 16 may be a red-emitting LED, and LED 18 may be a white-emitting LED. In another exemplary embodiment, at least one of LEDs 14 and 16 may be a blue-emitting LED with a red-emitting wavelength converting material disposed in the path of blue light. Any suitable LEDs may be used in the horticultural lighting system 300 .

In the exemplary system of FIG. 3 , LEDs 14 , 16 and 18 may be mounted on base 12 . The base 12 can be any structure that provides power to the LEDs used in the system 300 . Base 12 may include a separate control channel and a means for switching all or part of the drive current from a horticultural light source (eg, LEDs 14, 16, and 18) to the control channel. The base 12 may be, for example, a printed circuit board. The base 12 can be coupled to a processor 22 and the communication interface 25 . The base 12 may also have wired connectivity via an Ethernet (IEEE 802.3 standard) based network, wireless connectivity via an IEEE 802.11 based Wireless Local Area Network (WLAN) and/or based on one of the 3GPP standards Cellular connection and/or short-range wireless connectivity capabilities to mobile phones or other devices such as a Bluetooth wireless communication interface, infrared interface or any other suitable short-range wireless communication interface such as a LiFi. Base 12 may be capable of receiving control signals from a network of control horticultural light sources (eg, LEDs 14, 16, and 18).

The LEDs 14, 16, and 18 can be directed in a particular direction in which a plant or a plant bed of a plurality of plants in plant plant bed 100 can be positioned. LEDs 14 , 16 and 18 may direct light 102 towards plant bed 100 .

The processor 22 may be, for example and without limitation, a microprocessor or microprocessors, a single-core or multi-core processor, a general-purpose processor, a special-purpose processor, a conventional processor, a graphics processor unit (GPU), a digital signal processor (DSP), one or more microprocessors associated with a DSP core, a controller, a microcontroller or any other unit, module capable of executing a sequence of instructions or machine.

Processor 22 may control the operation of LEDs 14 , 16 and 18 and control the supply of power to LEDs 14 , 16 and 18 . Processor 22 can execute instructions stored in memory device 24 coupled to processor 22 . Examples of instructions executable by processor 22 are described herein.

Memory device 24 may be, for example, such as a dynamic random access memory (D-RAM), static RAM (S-RAM), other RAM, a flash memory, or any other suitable computer-readable medium such as A device used to store, for example, results or any other data produced by a sensor, a non-transitory computer-readable medium. Examples of a computer-readable medium include, but are not limited to, a register, a cache, an electronic circuit, an optical medium, a read only memory (ROM), a semiconductor memory device (such as any type of RAM), a magnetic medium (such as a hard disk drive, a tape drive, a magneto-optical medium, or a floppy disk drive), a flash memory medium (such as a USB flash drive or a flash memory card) ), a flash-based or D-RAM-based solid state drive (SSD), an optical disc (such as a CD, DVD or BD), or any other suitable device for electronic data storage.

The processor 22 may also be coupled to the communication interface 25 . Communication interface 25 may be, for example, any device capable of communicating with a network and communicating results or any other suitable data. Communication interface 25 may also include transceivers, receivers and/or transmitters capable of providing access and communication in a wireless network or a wired network. For example, the communication interface 25 may have wired connection capability via an Ethernet (IEEE 802.3 standard) based network. For example, the communication interface 25 may also have wireless connectivity capabilities via an IEEE 802.11 based wireless local area network (WLAN) and cellular connectivity based on the 3GPP standard. In another example, the communication interface 25 may also have short-range wireless connectivity capabilities to a mobile phone or other device, such as a Bluetooth wireless communication interface, an infrared interface, LiFi, or any other suitable short-range wireless communication interface.

Communication interface 25 may also include a display or connection to a display device. Communication interface 25 may also include a device or devices for receiving user input, such as, for example, a keyboard, a mouse, or a touch screen.

The exemplary system of FIG. 3 may include sensor 20 . Sensor 20 may be an electronic sensor or other monitor or detection device, such as a camera or a voice recognition device. For example, the sensor 20 may be an ultrasonic sensor, a color sensor, a humidity sensor, a temperature sensor and/or a motion sensor. In some embodiments, sensor 20 is a motion sensor, or any other sensor that can detect, for example, the occupancy of an area or location by a person. Sensor 20 can generate data for each plant, each plant bed, each light fixture, each LED, or each plurality of LEDs. Sensor 20 may be capable of sending the results or any other data generated to memory device 24 and/or communication interface 25 for storage and/or transmission over a network. Data generated by sensor 20 may be sent to a central location via a network, such as the Internet. Alternatively or additionally, the data generated by sensor 20 may be downloaded to a wireless communication device, such as a mobile phone or other handheld device or laptop. The data generated by the sensor 20 can be downloaded to the wireless communication device on a per plant, per plant bed, per lamp, per LED or per LED basis.

Sensor 20 may be positioned on base 12 in the same location as the light sources (eg, LEDs 14, 16, and 18) used for horticultural lighting. Horticultural lighting sources, such as LEDs 14, 16, and 18 in exemplary horticultural lighting system 300, may be mounted directly above plant beds 100, for example, with one lighting system per plant bed, which may, for example, be the most Optimize the light distribution to 100 plant beds. In an exemplary embodiment, the sensors 20 of the horticultural lighting system 300 may monitor and detect various events or changes in the environment of the horticultural lighting system 300 . Sensor 20 may be mounted such that it does not interfere with or significantly absorb light emitted by light sources (eg, LEDs 14, 16, and 18) used for horticultural lighting.

Since horticultural light is generally dominated by blue and red wavelengths, the color rendering index of horticultural light is very low. Therefore, horticultural light makes work uncomfortable and makes accurate visual detection of plants difficult. In some embodiments, the system 300 of FIG. 3 may include light that can emit white light (ie, light with a color rendering index more suitable for visual inspection of work or plants) or light in a color (which is mixed with horticultural light sources) One LED (eg, LED 18) of light with a color rendering index more suitable for visual inspection of work or plants is generated. In some embodiments, LED 18 may be a blue-emitting LED in combination with one or more wavelength converting materials to produce white light, or LED 18 may be, for example, one of the green-yellow emitting light that fills the spectrum produced by other horticultural light sources LED.

4 is a flow diagram of an exemplary process 400 for detecting state changes in a horticultural lighting system that may be executed in the exemplary system 300 described above and used in combination with any of the embodiments described herein. Although the steps of the process 400 in FIG. 4 are shown and described separately, the steps may be performed in an order other than that shown, in parallel with each other, or concurrently with each other. For illustrative purposes, the process of FIG. 4 is performed by system 300, but it may also be performed by any of the devices and systems described herein. For example, program 400 in FIG. 4 may be stored in memory device 24 and executed by processor 22 . In the exemplary process 400 in FIG. 4 , the sensor 20 may be one capable of detecting various state changes, such as states associated with ultrasound, color, humidity, or temperature, as described above with respect to FIG. 3 . device.

In the example of Figure 4, activation 26 is a light source for horticultural lighting. Sensor 20 can detect a state 40 . State 40 may be, for example, plant canopy height and/or plant canopy density and/or any other suitable state detectable by ultrasound. The detected state 40 may be, for example, a measure of leaf health and/or a measure of flowering state and/or any other suitable state that may be detected by a color sensor. The detected state 40 may be, for example, a change in humidity. The detected state 40 may be, for example, a change in temperature. The sensor 20 may automatically detect the status after a predetermined event occurs, or after, for example, a user-generated input is received via the communication interface 25 (eg, after a predetermined time, or after a predetermined time interval). . In some embodiments, the detected state 40 may be a signal from a remote control, a voice enable signal, or from a wireless communication device such as a mobile phone or a wireless communication system such as, for example, an IEEE 802.11 Reception of a signal in a WLAN, a cellular network) or other devices operating via a Bluetooth interface). The signal can be received through the communication interface 25 or through the sensor 20 .

If the detected state 44 indicates no change, the light source does not change. If the detected state 42 indicates a change, then the horticultural lighting is changed 46. For example, the amount of current supplied to the LEDs in the light source can be changed, or some LEDs can be activated or deactivated when changing 46 . Any suitable changes to horticultural lighting can be performed. In another example, horticultural lighting is modified 46 by cycling through many LED colors to increase the sensitivity of a camera to specific plant photoreceptors.

Notification 48 may be generated and communicated in system 300 . For example, the timing and details of changes 46 may be stored in memory device 24 or communicated to a user via communication interface 25. Next, the system may wait 50 for the next state detection event.

5 is a flow diagram of an exemplary process 500 for detecting occupancy in a horticultural lighting system that may be executed in the exemplary system 300 described above and used in combination with any of the embodiments described herein. Although the steps of the process 500 in FIG. 5 are shown and described separately, the steps may be performed in an order other than that shown, in parallel with each other, or concurrently with each other. For illustrative purposes, the process of FIG. 5 is performed by system 300, but it may also be performed by any of the devices and systems described herein. For example, the process 500 in FIG. 5 may be stored in the memory device 24 and executed by the processor 22 . In the exemplary process 500 in FIG. 5, the sensor 20 may be a sensor capable of detecting occupancy, such as by motion, temperature change, or by reception of a signal, as described above with respect to FIG. 3 .

In the example of FIG. 5, the sensor 20 may determine whether an area 30 is occupied. For example, occupancy may be detected based on the detection of motion within a predetermined distance from the plant bed 100 . In another example, occupancy can be based on a temperature change or humidity change. If no occupancy is detected, a first light source can be activated 36 . The first light source may, for example, be a horticultural light source (eg, LEDs 14, 16 and/or 18).

If occupancy is detected, a second light source can be activated 32 . The second light source can, for example, be a white light source (eg, LEDs 14, 16 and/or 18). The spectrum of horticultural light sources and white light sources can be different. Alternatively, white light can be generated by filling in the missing spectrum between red and blue dominant horticultural lighting. Other modes may also be used, such as reducing normal lighting power and backfilling the spectrum.

In some embodiments, when sensor 20 receives a signal via a remote control signal, via voice activation, or when sensor 20 receives a signal from a wireless communication device such as a mobile phone or a wireless communication system such as When receiving a wireless signal, such as an IEEE 802.11 WLAN, a cellular network, LiFi or other devices operating in a Bluetooth signal), occupancy can be detected and the second light source activated 32.

When activating 32 the second light source, the activation of the second light source may be according to a preconfigured mode or a user-specific mode. For example, one mode may activate all LEDs (eg, LEDs 14, 16, and 18) or only a portion of the LEDs (eg, only LEDs 14, 16, or 18, or a combination of one of LEDs 14, 16, or 18) . For example, these modes may be preconfigured based on a detection mode or a task associated with a particular user.

In some embodiments, sensor 20 may restart process 500 after a time delay 34 . Time delay 34 may be configured by a user and/or stored in memory device 24 .

As described above, broad-spectrum light (ie, white light) from a source, such as the sun, is typically used to illuminate a plant's environment. Plants can then be analyzed using a multispectral camera as described above.

FIG. 6 is a diagram of an exemplary horticultural lighting system 600 configured to observe plant health. Horticultural lighting system 600 may include a horticultural light source, such as at least one LED of a plurality of LEDs (in the example of FIG. 6, LEDs 14 and 16). The exemplary system 600 may also include the processor 22 , the memory device 24 , the communication interface 25 , the plant bed 100 and the base 12 as described above with respect to FIG. 3 . The exemplary system 600 may include other components, such as sensors or any other devices described herein.

LEDs 14 and 16 may include multiple narrowband light sources. Narrow frequency as used in the embodiments described herein may refer to one of no wider than 100 nm in some embodiments, no more than 50 nm in some embodiments and no more than 30 nm in some embodiments One of the LEDs in the wavelength band that emits 95% of the light from the LED. Although two LEDs 14 and 16 are shown in the example of FIG. 6 , any number of LEDs may be used, such as LED 18 or more LEDs as described above with respect to FIG. 3 . The wavelength band of LEDs used in horticultural light sources can be selected to target light absorbing compounds for plants grown in system 600 of FIG. 6 . Therefore, the system 600 can illuminate the plant environment using narrow-band light, which can enable observation of the health of the plants in the plant bed 100 .

For example, LEDs 14 and 16 may be swept across wavelengths of light in the spectrum of interest while capturing an image of plant bed 100 using a broad-spectrum black-and-white (B&W) camera, such as camera 54 . Camera 54 may be controlled by processor 22 . The LEDs 14 and 16 of the horticultural light source and the camera 54 may be attached to the base 12 .

Camera 54 can be positioned to capture images of the plants in plant bed 100 positioned below LEDs 14 and 16 . Images captured by camera 54 may be stored by memory device 24 and transmitted via communication interface 25 over a network such as, for example, the Internet, a WLAN, or a cellular network. Camera 54 may be mounted such that it does not interfere with or significantly absorb light emitted by light sources used for horticultural lighting (eg, LEDs 14 and 16).

The LEDs 14 and 16 may be individually controlled and activated, for example, by the processor 22 of the system 600 to generate a particular spectrum and illuminate the plant bed 100 with narrow-band light 102 of different wavelengths. The processor 22 can run through the available LED wavelengths, activate the appropriate LEDs that generate light 102 in those wavelengths, and activate the camera 54 to capture images of the plant bed 100 . By selectively illuminating the plant bed 100 with each wavelength of interest and capturing an image using the camera 54 under that illumination, the relative absorption of plants at those wavelengths can be effectively measured. The relative absorption of different wavelengths can indicate the presence or activity of specific chlorophyll, carotenoids, and other light absorbing molecules, which can be indicative of plant health. Therefore, the use of high-cost multispectral cameras can be avoided.

In another example, a specific mix of light spectra can be activated by LEDs 14 and 16 that can guide the growth of plants in a beneficial manner.

Figure 7 is an example system that can be implemented in the exemplary systems 300 or 600 described above and used in combination with any of the embodiments described herein for capturing plants by illumination with various wavelengths of light in a horticultural lighting system A flow chart of an exemplary process 700 for observing plant health from images. Although the steps of the process 700 in FIG. 7 are shown and described separately, the steps may be performed in an order other than that shown, in parallel with each other, or concurrently with each other. For illustrative purposes, the process of FIG. 7 is performed by system 300 or 600, but it may also be performed by any of the devices and systems described herein. For example, the process 700 in FIG. 7 may be stored in the memory device 24 and executed by the processor 22 . In the exemplary process 700 of FIG. 7 , camera 54 may be one as described above with respect to FIG. 6 or any camera capable of executing the process 700 of FIG. 7 .

In the example of FIG. 7, a first portion of the spectrum of 60 horticultural light sources can be activated. For example, a single narrow frequency LED can be activated. An image of a target, such as a plant or plant bed, can be captured 62 by the camera 54 . Images may be stored and/or communicated 64 via memory device 24 and communication interface 25 . For example, images can be displayed on a monitor, sent to a cellular phone, and/or stored in memory. Next, the system may determine if all spectra of interest are complete 66 . If all spectra of interest are completed 70, then all LEDs in the horticultural light source can be activated 72 or restarted. When the horticultural light source is activated 72, the monitoring has ended and the system returns to lighting the plants for growth. If the entire spectrum has not been completed, the system restarts the process 700 and activates 60 the lower portion of the horticultural light source spectrum. The first part of the horticultural light source spectrum can be deactivated so that only one spectrum is activated per image during monitoring. For example, a different narrow frequency LED can then be activated.

Although in the above examples the semiconductor light emitting devices are group III nitride LEDs emitting blue or UV light and group III phosphide or group III arsenide LEDs emitting red or other color light, other than LEDs may be used. Other semiconductor light emitting devices (such as laser diodes) and semiconductor light emitting devices made of other material systems (such as other III-V materials, II-VI materials, ZnO or Si-based materials). A blue or UV light emitting device can be combined with one or more wavelength converting materials to produce light of different colors, such that the combined light from the light emitting device and wavelength converting material appears white or any other color desired for a given application.

FIG. 8 is a diagram of an exemplary horticultural lighting system 800 . Exemplary horticultural lighting system 800 may include sensor 20 and base 12 as described above with respect to FIG. 3 . Exemplary horticultural lighting system 800 may include a horticultural light source, such as at least one LED 14 that emits light 102 toward plant bed 100 . Although one LED (LED 14) is shown in the example of Figure 8, any number of LEDs may be used, such as LEDs 16 and 18 or more LEDs as described above with respect to Figure 3 .

In the exemplary horticultural lighting system 800 of FIG. 8, the sensor 20 is mounted such that it does not interfere with or substantially absorb the light emitted by the light source. FIG. 8 is a cross-section illustrating a portion of a horticultural lighting system 800 in which an example of sensor 20 is installed. In FIG. 8 , at least one LED 14 is attached to the base 12 as all or part of a horticultural light source. Structure 80 , which may include reflective sidewalls 82 that slope outwardly from the light source, may direct light 102 toward plant bed 100 . The sensor 20 is attached to the base 12 adjacent to the LED 14 . LED 14 may include an optics (not shown) to direct light away from sensor 20 and toward the output direction depicted by light 102 . The sensor 20 can be positioned so that it does not absorb much light from horticultural light sources.

Having thus described various embodiments, it should be understood and appreciated by those skilled in the art that many physical changes (of which only a few are exemplified in the foregoing detailed description) may be made to the methods and apparatus described herein without Change the inventive concepts and principles embodied in this document. Accordingly, the present examples should be considered in all respects to be illustrative and non-restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and therefore equivalents within the claims All changes within the meaning and scope of the term shall be embraced therein.

Although features and elements are described above in specific combinations, it should be understood that each feature or element can be used alone or in any combination with or without other features and elements. Any single embodiment described herein may be supplemented with one or more elements from any one or more of the other embodiments described herein. Any single element of one embodiment may be replaced with one or more elements from any one or more of other embodiments described herein. For example, each feature or element as described herein with reference to any of FIGS. 1-8 may be used alone without the use of other features and elements or with or without the Various combinations of other features and elements of each or any combination of the other figures are used. The sub-elements of the methods and apparatus described herein with reference to FIGS. 1-8 may be performed in any arbitrary order, including concurrently, in any combination or subcombination.

12‧‧‧Base 14‧‧‧Light Emitting Diode (LED)16‧‧‧Light Emitting Diode (LED)18‧‧‧Light Emitting Diode (LED)20‧‧‧Sensor22‧‧‧Processing Device 24‧‧‧Memory Device 25‧‧‧Communication Interface 26‧‧‧Enable 30‧‧‧Occupied 32‧‧‧Enable 34‧‧‧Time Delay 36‧‧‧Enable 40‧‧‧Status 42‧‧‧All Detected State 44‧‧‧Detected State 46‧‧‧Change 48‧‧‧Notify 50‧‧‧Wait 54‧‧‧Camera 60‧‧‧Activate 62‧‧‧Capture 64‧‧‧Save and/or Convey 66‧‧‧Complete 70‧‧‧Complete 72‧‧‧Start 80‧‧‧Structure 82‧‧‧Reflecting Sidewall 100‧‧‧Curve / Plant Bed 102‧‧‧Light / Narrowband Light 200‧‧‧ Horticultural Lighting Installation 300‧‧‧Horticultural Lighting System 400‧‧‧Program 500‧‧‧Program 600‧‧‧Horticultural Lighting System 700‧‧‧Program 800‧‧‧Horticultural Lighting System

Fig. 1 is a graph of photosynthetic efficiency (arbitrary unit) as a function of wavelength (nm);

2 is a graph of intensity (arbitrary units) as a function of wavelength (nm) for a horticultural lighting device;

3 illustrates a horticultural lighting system including a sensor;

4 is a flow chart of a state detection method performed on the system of FIG. 3;

FIG. 5 is a flowchart of an occupancy detection method performed on the system of FIG. 3;

6 depicts a horticultural lighting system configured to observe plant health;

FIG. 7 is a flowchart of a method performed on the system of FIG. 6;

8 shows an LED and a sensor attached to a base and positioned within a structure with reflective sidewalls.

12‧‧‧Pedestal

14‧‧‧Light Emitting Diode (LED)

16‧‧‧Light Emitting Diode (LED)

22‧‧‧Processor

24‧‧‧Memory Devices

25‧‧‧Communication interface

54‧‧‧Camera

100‧‧‧Graph/Plant bed

102‧‧‧Light/Narrowband Light

600‧‧‧Horticultural lighting system

Claims (15)

A method for horticultural lighting, comprising: capturing a first image of the plant using a broad-spectrum camera while illuminating a plant with a first narrowband light from a first LED; and While a second narrowband light of a second LED illuminates the plant and is not illuminated by the first narrowband light, a second image of the plant is captured by the broad-spectrum camera; using the first image and the first Two images determine a relative absorption by the plant of the first narrowband light and the second narrowband light, wherein the relative absorption is an indication of the health of the plant. The method of claim 1, wherein the first narrowband light comprises blue light. The method of claim 1, wherein the second narrowband light comprises red light. The method of claim 1, further comprising simultaneously illuminating the plant with the first narrowband light and the second narrowband light. A system for horticultural lighting, comprising: a first LED configured to emit light having a first narrow frequency spectrum toward a plant; a second LED configured to emit light having a second narrow-band spectrum light directed toward the plant; a broad-spectrum camera configured to pass light from the first narrow-band spectrum at the plant capturing a first image of the plant while noting that the plant is not illuminated by light from the second narrowband spectrum; and the broad spectrum camera is further configured to detect when the plant is illuminated by light from the second narrowband spectrum A second image of the plant is captured while the light illuminates the plant and is not illuminated by the light of the first narrowband spectrum. The system of claim 5, wherein the first narrowband spectrum is different from the second narrowband spectrum. The system of claim 5, wherein the first narrowband spectrum comprises blue light. The method of claim 5, wherein the second narrowband spectrum comprises red light. 5. The system of claim 5, further comprising: a third LED configured to emit light having a third narrow-band spectrum toward the plant; and the broad-spectrum camera further configured to A third image of the plant is captured while the light from the third narrowband spectrum illuminates the plant and is not illuminated by the light from the first narrowband spectrum and the second narrowband spectrum. The system of claim 5, wherein the broad spectrum camera is mounted such that it does not absorb light from the first LED or the second LED. A method for horticultural lighting, comprising: Detects whether a space near a plant is occupied by a person; if occupancy is not detected, uses light from a first LED configured to emit blue light and a second LED configured to emit red light light to illuminate the plant; and if occupancy is detected, use the light from the first LED, the light from the second LED, and a third LED configured to emit light of a color other than blue or red LED lighting the plant. The method of claim 11, wherein the light other than blue light or red light is yellow-green light. The method of claim 11, wherein the light from the first LED, the light from the second LED, and the light from the third LED combine into white light. The method of claim 11, further comprising: detecting whether the space near the plant is occupied a second time after a time delay. The method of claim 14, further comprising: if a second occupancy is not detected, illuminating the plant using light from the first LED, the second LED, but not the third LED .

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