Method and system for illuminating plants with artificial light

Abstract

A computer-implemented method for controlling one or more lighting fixtures configured to illuminate one or more plants with artificial light is disclosed. The artificial light includes a plurality of artificial light components. Each of the artificial light components is of a respective wavelength or wavelength range. The plurality of artificial light components includes a first artificial light component of a first wavelength or wavelength range and a second artificial light component of a second wavelength or wavelength range. Further, sunlight is incident on the one or more plants. The sunlight includes a plurality of sunlight components. Each of the sunlight components is of a respective wavelength or wavelength range. The plurality of sunlight components includes a first sunlight component of a first wavelength or wavelength range and a second sunlight component of a second wavelength or wavelength range. The method includes receiving a signal indicative of a non-spectral decomposition irradiance value of sunlight incident on the one or more plants.

Description

Technical Field

[0001] The present disclosure relates to methods and systems for illuminating one or more plants with artificial light. In particular, such methods and systems involve - sunlight incident on one or more plants, - artificial light that should be incident on one or more plants, a signal indicative of a non-spectrally resolved irradiance value of at least one of them. The present disclosure further relates to a computer program, a computer-readable storage medium, and a controller for performing such a method.

Background Art

[0002] To enable year-round production of crops in greenhouses such as tomatoes, many producers are currently using supplemental lighting such as LED lighting, especially in autumn, winter, and spring, where daylight levels are generally insufficient for tomato growth in the northern countries and tomato prices are high.

[0003] More generally referred to as artificial light, supplemental lighting can be applied above the plant canopy (so-called top-lighting) or from within the plant canopy (so-called inter-lighting).

[0004] Plants use light as an energy source to absorb CO2 from the surrounding air and convert it into biomass. This process is called photosynthesis. A portion of the biomass is partitioned into fruits (such as tomatoes). Therefore, light is essential for plant and fruit growth. In modern greenhouses, environmental parameters such as climate and irrigation are well controlled, which means that the availability of light is a limiting factor for growth.

[0005] The process of photosynthesis occurs mainly in response to light within a certain wavelength range. This range is approximately 400 - 700 nm. Radiation within this range is called photosynthetically - active - radiation (PAR).

[0006] The PAR light level is represented in μmol / s / m 2 and 1 mole of light corresponds to the number of photons equal to Avogadro's number (6.0x10 23 ).

Summary of the Invention

Problems to be Solved by the Invention

[0007] Artificial lighting in horticulture consumes energy, so the operating cost is considerable and it results in a non - negligible carbon footprint when electricity generated from fossil fuels is used. Therefore, it is desirable to reduce energy consumption.

[0008] US 2016 / 0088802 discloses a lighting system and method for growing plant seedlings, including at least one light source for illuminating the plant seedlings with growth light during the growth stages of the plant seedling growth process, and a controller for controlling the spectral power distribution of the growth light emitted from the light source such that the growth light in at least some growth stages of the plant seedling growth process has greater energy in the blue wavelength range than the energy in other growth stages of the plant seedling growth process. In a use - case where available daylight is supplemented by the growth light, additional sensors may be used to measure the amount and spectral components of the daylight and control the growth light so that the spectral power distribution of the total light received by the plant seedlings is correspondingly controlled.

[0009] US 2015 / 0128489 discloses a plant growth system in which a first light source irradiates plants with light having peak wavelengths in the range of 380 to 560 nm and peak wavelengths in the range of 560 to 680 nm, and a second light source irradiates plants with far-red light having a peak wavelength in the range of 685 to 780 nm. Further, a control unit controls the first and second light sources to perform respective irradiation operations, and a time setting unit sets first and second time periods for the control unit to control the first and second light sources to perform respective irradiation operations. The first time period is in the range from a first predetermined time before sunset to a second predetermined time after sunset, and the second time period starts after the first light source finishes its irradiation operation.

[0010] US 2018 / 0116127 relates to a system and method for illuminating plants that provides supplemental lighting to plants in addition to natural light and improves crop yields when using such supplemental lighting. The present invention is suitable for use in horticulture in greenhouses.

Means for Solving the Problems

[0011] To that end, a computer-implemented method for controlling one or more lighting fixtures configured to illuminate one or more plants with artificial light is disclosed. The artificial light includes a plurality of artificial light components. Each of the artificial light components is of a respective wavelength or wavelength range. The plurality of artificial light components includes a first artificial light component of a first wavelength or wavelength range and a second artificial light component of a second wavelength or wavelength range. Further, sunlight is incident on the one or more plants. The sunlight includes a plurality of sunlight components. Each of the sunlight components is of a respective wavelength or wavelength range. The plurality of sunlight components includes a first sunlight component of a first wavelength or wavelength range and a second sunlight component of a second wavelength or wavelength range. The method includes receiving a signal indicative of the non-spectral decomposition irradiance value of sunlight incident on the one or more plants.

[0012] The method further includes determining a first irradiance value for a first artificial light component and a second irradiance value for a second artificial light component based on the non-spectral decomposition irradiance values. The method further includes controlling one or more lighting fixtures to provide one or more plants with artificial light having the determined first irradiance value for the first artificial light component and the determined second irradiance value for the second artificial light component such that the one or more plants receive light of a first wavelength or wavelength range at a first predefined irradiance value and light of a second wavelength or wavelength range at a second predefined irradiance value.

[0013] Advantageously, the method enables the energy-efficient supply of sufficient PAR to one or more plants, even if the irradiance values of different light components in sunlight vary relative to each other, or, broadly speaking, even if the shape of the EM spectrum of sunlight changes. The EM spectrum of sunlight is known to change during the day. For example, the EM spectrum of sunlight during the day includes relatively strong blue and green light components relative to the red light component in sunlight, while at sunset, the EM spectrum of sunlight exhibits relatively weak blue and green light components relative to the red light component in sunlight. By being able to adapt the different light components of the artificial light separately, each artificial light component in the artificial light can be specifically adapted as needed in response to changes in the corresponding light component in sunlight. If, for example, only the irradiance values of the blue and green light components of sunlight decrease at dusk, then in order to maintain an acceptable PAR spectral power distribution, the red light component need not increase, and only an increase in the blue and green artificial light components in the artificial light would be necessary. For example, an increase in the artificial red light component, which is carried out when only the total irradiance value of the artificial light can be controlled, may result in an irradiance level of red light that is too high for one or more plants. In such a case, a portion of the generated artificial red light component may not be used for photosynthesis and may thus be lost. Thus, the method enables the maintenance of a high level of light use efficiency (LUE), typically expressed in g / mol. Light use efficiency (LUE) defines the vegetation efficiency that converts radiant energy into biochemical energy through photosynthesis. LUE represents how efficiently a plant utilizes the incident light for growth. LUE can be calculated by dividing the dry weight of the plant by the total incident light received by the plant over the growth period.

[0014] This method is further advantageous in that it enables a plant to receive appropriate irradiance values for first and second wavelengths (ranges) without the need to measure the spectrum of sunlight incident on one or more plants and / or without the need for a spectrally decomposed input control signal, i.e., a control signal indicating separate irradiance values for separate wavelengths or wavelength ranges. Thus, this method enables the use of a relatively simple irradiance sensor, e.g., a sensor capable of measuring only the total irradiance value for a certain fixed wavelength range, e.g., the PAR wavelength range or the visible light wavelength range, and / or a relatively simple control infrastructure, e.g., a control infrastructure that requires only the irradiance value for the overall artificial light to be incident on one or more plants as a control input, while at the same time ensuring that the plant receives appropriate irradiance levels for different wavelengths or wavelength ranges.

[0015] The signal may represent the (non-spectrally decomposed) total irradiance value of the incident sunlight in that it represents irradiance values for a relatively broad wavelength range that is broader than the first and second wavelength ranges. This typically depends on the sensor used to measure the total irradiance of sunlight. The total irradiance value may represent irradiance over a substantial part of the photosynthetic active radiation (PAR) wavelength range from 400 nm to 700 nm. Alternatively, the total irradiance value may represent irradiance over a substantial part of the visible wavelength range from about 380 nm to about 750 nm. Further, the total irradiance value may represent irradiance over a part of the full-spectrum sunlight radiation considered useful for the life of plants and animals, from near ultraviolet to near infrared, i.e., from about 300 nm to about 1400 nm. This relatively broad wavelength range may or may not include the first wavelength or wavelength range and may or may not include the second wavelength range. This relatively broad wavelength range may include wavelengths that are not in the first wavelength range and not in the second wavelength range.

[0016] Preferably, the signal indicates the total irradiance value of sunlight incident on one or more plants immediately before the first time or the second time. In one embodiment, the signal indicating the current total irradiance value of sunlight is received repeatedly, such as every second or every minute, so that the irradiance values of the first artificial light component and the second artificial light component can be repeatedly determined for any time, and also for the first time and the second time.

[0017] Of course, based on the indicated total irradiance value of sunlight, more irradiance values may be determined for more respective wavelengths or wavelength ranges.

[0018] The light received by one or more plants is a combination of sunlight and artificial light. Thus, it may be understood that the supply of light of the first wavelength or wavelength range at the first predetermined irradiance value means that the irradiance value of the first artificial light component + the irradiance value of the first sunlight component is equal to the first predetermined irradiance value.

[0019] Preferably, the non-spectral resolved irradiance value is one total irradiance value for one or more wavelength ranges. Preferably, the signal indicates only one irradiance value.

[0020] Preferably, the signal does not include spectrally resolved data, and thus does not indicate different irradiance values for different light components of the light, i.e., the light to which the signal relates. Spectrally resolved data may be understood as data indicating at least a first irradiance value for a first wavelength or wavelength range and a second irradiance value for a second wavelength or wavelength range.

[0021] Determining the first irradiance value for the first artificial light component and the second irradiance value for the second artificial light component may be done by determining an appropriate electromagnetic (EM) spectrum for the artificial light. Determining the EM spectrum may be understood, per definition, to include determining separate irradiance values for separate light components.

[0022] The first and second predetermined irradiance values may be the same or different. For each of a plurality of times, a light recipe defining the EM spectrum that one or more plants should receive may be defined for the one or more plants. Such a light recipe may be determined based on various factors, for example, based on the plant species and / or the age / life phase of the plant, and / or based on the time when the plant is illuminated, such as the season, time of day, and / or based on the amount of light (number of photons) received during a previous period, such as the past two days, and / or based on the amount of light (number of photons) that one or more plants are predicted to receive, for example, in the next two days. Of course, the desired EM spectrum may be the same for the first time and the second time, as mentioned above.

[0023] Controlling one or more lighting fixtures may include separately adjusting the irradiance of each of the different artificial light components. This may be done by sending a respective control signal to each of a plurality of lighting devices, each lighting device being configured to generate a respective artificial light component. By way of example, the first lighting device may be a green light LED, the second lighting device may be a blue light LED, and the third lighting device may be a red light LED. By sending different control signals to these different LEDs, the components of the artificial light, the EM spectrum, can be appropriately controlled, at least with respect to the blue, green, and red artificial light components in the artificial light. Each light component may be said to be associated with a color channel of the lighting system. Using this terminology, separately adjusting the irradiance of each light component may be done by separately controlling each color channel of the lighting system. A lighting fixture may include one type of lighting device configured to generate one artificial light component, or a lighting fixture may include a plurality of different types of lighting devices, each configured to generate a different artificial light component.

[0024] It should be understood that the light components used herein may refer to wavelength ranges. This may be understood to mean that the light component includes only light of wavelengths within the range and does not include light having wavelengths outside the range. The light components of the artificial light may be understood to have non-overlapping wavelengths and / or non-overlapping wavelength ranges. Alternatively, the light components of the artificial light may have overlapping wavelength ranges. In any case, if the light component is of a wavelength range, adjusting the irradiance of the light component does not necessarily mean that the irradiance of all wavelengths within the wavelength range is adjusted by the same factor.

[0025] As used herein, "irradiance" is the flux density expressed in watts per square meter at the plant level (e.g., leaf), μmol / s / m 2It can be represented by. Typically, adjusting the irradiance of the artificial light component incident on one or more plants is done by adjusting the "radiant flux" of the artificial light component generated by the lighting device. The radiant flux can be expressed in watts. In a specific setup of one or more plants and a lighting device, the irradiance of the artificial light component incident on the one or more plants is linked to the radiant flux of the said artificial light component generated by the lighting device. This relationship between the radiant flux and the irradiance can be determined in a straightforward manner, for example, simply by setting the radiant flux from the lighting device for the artificial light component to respective radiant flux values and measuring the irradiance values in one or more plants for each value. Considering the above, determining the irradiance value may also refer to determining the corresponding radiant flux value that the lighting device should generate. Similarly, adjusting the irradiance of one or more plants incident on a certain light component may also refer to adjusting the radiant flux of the said light component generated by the lighting device.

[0026] In the present disclosure, unless otherwise indicated, the following definitions are used: · "First irradiance value" refers to the irradiance value for the first artificial light component of the first wavelength or wavelength range at the first time. · "Second irradiance value" refers to the irradiance value for the second artificial light component of the second wavelength or wavelength range at the first time. · "Third irradiance value" refers to the irradiance value for the first artificial light component of the first wavelength or wavelength range at the second time. · "Fourth irradiance value" refers to the irradiance value for the second artificial light component of the second wavelength or wavelength range at the second time. · "The fifth irradiance value" refers to the irradiance value for the first sunlight component of the first wavelength or wavelength range at the first time. · "The sixth irradiance value" refers to the irradiance value for the second sunlight component of the second wavelength or wavelength range at the first time. · "The seventh irradiance value" refers to the irradiance value for the first sunlight component of the first wavelength or wavelength range at the second time. · "The eighth irradiance value" refers to the irradiance value for the second sunlight component of the second wavelength or wavelength range at the second time. · "The first predetermined irradiance value" refers to the predetermined irradiance value for the first wavelength or wavelength range at the first time. · "The second predetermined irradiance value" refers to the predetermined irradiance value for the second wavelength or wavelength range at the first time. · "The third predetermined irradiance value" refers to the predetermined irradiance value for the first wavelength or wavelength range at the second time. · "The fourth predetermined irradiance value" refers to the predetermined irradiance value for the second wavelength or wavelength range at the second time.

[0027] In one embodiment, the non-spectral resolved irradiance value is the irradiance value of sunlight incident on one or more plants. In such an embodiment, determining the first and second irradiance values - Based on the non-spectral decomposition irradiance value, a fifth irradiance value of a first sunlight component incident on one or more plants, wherein the first sunlight component has a first wavelength or wavelength range, the fifth irradiance value, and a sixth irradiance value of a second sunlight component incident on one or more plants, wherein the second sunlight component has a second wavelength or wavelength range, determining the sixth irradiance value; - Based on a first predetermined irradiance value for the first wavelength or wavelength range and based on the fifth irradiance value of the first sunlight component, determining a first irradiance value for the first artificial light component; - Based on a second predetermined irradiance value for the second wavelength or wavelength range and based on the determined sixth irradiance value of the second sunlight component, determining a second irradiance value for the second artificial light component; may be included.

[0028] In this embodiment, a relatively simple optical sensor that can only measure non-spectral decomposition sunlight irradiance values may be used. This single irradiance value is sufficient to determine the irradiance values of the first and second sunlight components, as further described below. In one example, the complete EM spectrum of sunlight incident on one or more plants may be determined based on a single non-spectral decomposition irradiance value.

[0029] In a preferred embodiment, the first irradiance value is the difference between the first predetermined irradiance value and the fifth irradiance value. Similarly, the second irradiance value is the difference between the second predetermined irradiance value and the sixth irradiance value. Thus, determining the first irradiance value for the first artificial light component may include determining the difference between the first predetermined irradiance value and the first irradiance value for the first sunlight component. Determining the second irradiance value for the second artificial light component may include determining the difference between the second predetermined irradiance value and the second irradiance value for the second sunlight component. Thus, in one example, the method may include determining that the first sunlight component is not strong enough to provide the first predetermined irradiance value to one or more plants, and as a result, the irradiance value of the first artificial light component may be increased.

[0030] In one embodiment, the method includes storing sunlight reference data indicating a reference irradiance value for the first sunlight component and a reference irradiance value for the second sunlight component for each of a plurality of reference non-spectrally resolved irradiance values. Here, determining the irradiance value of the first sunlight component and the irradiance value of the second sunlight component is performed based on the sunlight reference data.

[0031] The sunlight reference data may indicate the time of day and / or the time of year, preferably the date, for each reference non-spectrally resolved irradiance value. In this case, the irradiance values of the first sunlight component and the second sunlight component may be determined based on the current time and / or the current time of year and based on the reference data.

[0032] In one example, for each pre - stored non - spectral decomposition of sunlight, e.g., total irradiance value, the complete EM spectrum of sunlight is stored. Based on this EM spectrum and on a predetermined irradiance value, appropriate irradiance values for each artificial light component can be determined, for example, by determining the difference between the EM spectrum of sunlight and a predetermined EM spectrum to be incident on one or more plants.

[0033] The non - spectral decomposition irradiance values of sunlight may be stored in association with a set of respective irradiance values for the sunlight components of sunlight in that a first relationship between the total irradiance of sunlight and the irradiance of a first sunlight component is stored and a second relationship between the total irradiance of sunlight and the irradiance of a second sunlight component is stored. Based on these relationships and given the non - spectral decomposition irradiance value of sunlight, the irradiance value of the first sunlight component and the irradiance value of the second sunlight component can be calculated.

[0034] Sunlight reference data may include estimated, calibrated or measured values for various sunlight components related to a reference non - spectral decomposition sunlight irradiance value.

[0035] In one embodiment, sunlight incident on one or more plants has a first electromagnetic (EM) spectrum at a first time and a second EM spectrum at a second time after the first time. The second EM spectrum is different from the first EM spectrum. In this embodiment, the received signal indicates the non-spectral resolved irradiance value of the sunlight incident on one or more plants at the first time. Further, this embodiment includes receiving a second signal indicating the non-spectral resolved irradiance value of the sunlight incident on one or more plants at the second time. This embodiment also includes determining a seventh irradiance value of a first sunlight component incident on one or more plants and an eighth irradiance value of a second sunlight component incident on one or more plants based on the second non-spectral resolved irradiance value. This embodiment also includes determining a third irradiance value for a first artificial light component based on a third predetermined irradiance value for a first wavelength or wavelength range and based on the determined seventh irradiance value of the first sunlight component, and determining a fourth irradiance value for a second artificial light component based on a fourth predetermined irradiance value for a second wavelength or wavelength range and based on the determined eighth irradiance value of the second sunlight component. In this case, the one or more lighting fixtures may be controlled to provide artificial light having a determined third irradiance value for the first artificial light component and a determined fourth irradiance value for the second artificial light component to the one or more plants such that the one or more plants receive light of the first wavelength or wavelength range at the third predetermined irradiance value and light of the second wavelength or wavelength range at the fourth predetermined irradiance value at the second time.

[0036] This embodiment enables spectrally selective adjustment of artificial light so that one or more plants receive appropriate horticultural light at any given time and fluctuations of sunlight non-spectral resolved irradiance and / or sunlight EM spectrum.

[0037] The first and second predetermined irradiance values may be specifically defined for a first time. The third and fourth predetermined values may be specifically defined for a second time.

[0038] The third predetermined value may be equal to the first predetermined value. Similarly, the fourth predetermined value may be equal to the second predetermined value. This is the case, for example, when the light recipe does not change between the first time and the second time.

[0039] It should be understood that for any given time, more predetermined irradiance values may be defined respectively for more wavelengths or ranges. For example, for any given time, the complete EM spectrum that one or more plants should receive may be defined.

[0040] Preferably, the first irradiance value and the fifth irradiance value determined for the first time add up to the first predetermined irradiance value. Similarly, preferably, the second irradiance value and the sixth irradiance value add up to the second predetermined irradiance value. Similarly, preferably, the third irradiance value and the seventh irradiance value add up to the third predetermined irradiance value. Similarly, preferably, the fourth irradiance value and the eighth irradiance value add up to the fourth predetermined irradiance value.

[0041] In one embodiment, the ratio E of the first irradiance value to the second irradiance value e1 / E e2 is different from the ratio E of the third irradiance value to the fourth irradiance value e3 / E e4 Additionally, or alternatively, the ratio E of the first irradiance value to the third irradiance value e1 / E e3 is different from the ratio E of the second irradiance value to the fourth irradiance value e2 / E e4

[0042] ​In this embodiment, the irradiance values of the first and second artificial light components are adjusted relative to each other, so that at any given time, an appropriate irradiance value can be provided for each artificial light component, such that the artificial light is not wasted in the sense that one or more plants receive an irradiance value higher than that defined / required.

[0043] In one embodiment, the first wavelength range is 400 - 500 nm (blue), and the second wavelength range is 600 - 700 nm (red). In another embodiment, the first wavelength range is 600 - 700 nm (red), and the second wavelength range is 700 - 800 nm (far red). In such embodiments, for the non - spectrally - resolved solar irradiance value, the total irradiance of sunlight incident on one or more plants at a second time may be lower and higher respectively than the total irradiance of sunlight incident on one or more plants at a first time. In such a case, preferably, the ratio E e1 / E e3 is respectively smaller and larger than the ratio E e2 / E e4 of the second irradiance value to the fourth irradiance value.

[0044] Preferably, when the fifth irradiance value E e5 is lower than a first predetermined irradiance value, the first irradiance value E e1 is non - zero and is selected such that one or more plants receive, at a first time, in total, light of the first wavelength or wavelength range at the first predetermined irradiance value. Preferably, when the fifth irradiance value E e5 is above the first predetermined irradiance, the first irradiance value E e1 is substantially zero.

[0045] Preferably, when the sixth irradiance value E e6 is lower than a second predetermined irradiance value, the second irradiance value E e2is selected such that one or more plants, rather than zero, receive, in total, light having a second wavelength or wavelength range at a second predetermined irradiance value at a first time. Preferably, when the sixth irradiance value E e6 is greater than or equal to the second predetermined irradiance, the second irradiance value E e2 is substantially zero.

[0046] Preferably, when the seventh irradiance value E e7 is lower than a third predetermined irradiance value, the third irradiance value E e3 is selected such that one or more plants, rather than zero, receive, in total, light having a first wavelength or wavelength range at a third predetermined irradiance value at a second time. Preferably, when the seventh irradiance value E e7 is greater than or equal to the third predetermined irradiance, the third irradiance value E e3 is substantially zero.

[0047] Preferably, when the eighth irradiance value E e8 is lower than a fourth predetermined irradiance value, the fourth irradiance value E e4 is selected such that one or more plants, rather than zero, receive, in total, light having a second wavelength or wavelength range at a fourth predetermined irradiance value at a second time. Preferably, when the eighth irradiance value E e8 is greater than or equal to the fourth predetermined irradiance, the fourth irradiance value E e4 is substantially zero.

[0048] These embodiments ensure that artificial light is not wasted.

[0049] In one embodiment, determining the first irradiance value E e1 includes determining the difference between the fifth irradiance value E e5 and the first predetermined irradiance value, and / or determining the second irradiance value E e2 includes determining the difference between the sixth irradiance value E e6 and the second predetermined irradiance value, and / or Determining the third irradiance value E e3 includes determining the difference between the seventh irradiance value E e7 and a third predetermined irradiance value, and / or Determining the fourth irradiance value E e4 includes determining the difference between the eighth irradiance value E e8 and a fourth predetermined irradiance value.

[0050] In one embodiment, the method comprises determining, e.g., measuring, a first total irradiance value E total1 received by one or more plants at a first time for a first wavelength or wavelength range, and controlling the irradiance of a first artificial light component total1 to impinge on one or more plants at the first irradiance value E e1 at the first time, based on the first total irradiance value E and based on a first predetermined irradiance value, and / or total2 determining, e.g., measuring, a second total irradiance value E total2 received by one or more plants at the first time for a second wavelength or wavelength range, and controlling the irradiance of a second artificial light component e2 to impinge on one or more plants at the second irradiance value E at the first time, based on the second total irradiance value E total3 and based on a second predetermined irradiance value, and / or total3 determining, e.g., measuring, a third total irradiance value E e3 received by one or more plants at a second time for the first wavelength or wavelength range, and controlling the irradiance of the first artificial light component to impinge on one or more plants at the third irradiance value E total4 at the second time, based on the third total irradiance value E total4Based on and based on a fourth predetermined irradiance value, at a second time, a fourth irradiance value E e4 controlling the irradiance of the second artificial light component so as to be incident on one or more plants at

[0051] Measuring the total irradiance value received by one or more plants at a certain time may be performed by positioning an irradiance sensor on the plant so that the sensor receives both artificial light and sunlight. Preferably, these total irradiance values are measured immediately before the first time and immediately before the second time. These measurements may be repeated, for example, every second, so that the artificial light can be appropriately adjusted at any time, for example, so that the artificial light has an appropriate EM spectrum at the first and / or second times.

[0052] In this embodiment, the method is E total1 、E total2 、E total3 、E total4 etc., and may include determining the difference between the total irradiance value received by one or more plants and a predetermined irradiance value such as a first, second, third, fourth predetermined irradiance value, etc. Based on this difference, the EM spectrum of the artificial light can be appropriately adjusted.

[0053] One aspect of the present disclosure is an illumination system for illuminating one or more plants with artificial light, the illumination system comprising: - an illumination device configured to generate artificial light having a plurality of artificial light components, each of the artificial light components being of a respective wavelength or wavelength range, and configured to separately adjust the irradiance of each light component; - a control system including a processor configured to execute the method according to any of the preceding claims using the illumination device; relates to an illumination system comprising.

[0054] The lighting device may include a plurality of lighting sources adapted to generate artificial light having a plurality of artificial light components. The plurality of lighting sources do not necessarily correspond one-to-one with the plurality of artificial light components. For example, a lighting device including a blue lighting source, a red lighting source, and a white lighting source may provide artificial light in the red wavelength range by using only the red and white lighting sources.

[0055] One aspect of the present disclosure relates to a control system including an input interface for receiving a signal indicating a non-spectral resolved irradiance value, an output interface for sending an irradiance value for a first artificial light component and an irradiance value for a second artificial light component to the lighting device, and a processor configured to execute any of the methods described herein.

[0056] One aspect of the present disclosure relates to a computer program including instructions for causing any of the lighting systems described herein to execute any of the methods described herein.

[0057] One aspect of the present disclosure relates to a computer-readable medium storing any of the computer programs described herein.

[0058] One aspect of the present disclosure relates to a controller including a processor configured to execute any of the methods described herein.

[0059] One aspect of the present disclosure relates to a computer including a computer-readable storage medium having computer-readable program code embodied therein, and a processor, preferably a microprocessor, coupled to the computer-readable storage medium, wherein in response to executing the computer-readable program code, the processor is configured to execute any of the methods described herein.

[0060] One aspect of the present disclosure relates to a computer program or a set of computer programs or a computer program product that includes at least one software code portion, where the software code portion is configured to execute any of the methods described herein when executed on a computer system.

[0061] One aspect of the present disclosure relates to a non-transitory computer-readable storage medium that stores at least one software code portion, where the software code portion is configured to execute any of the methods described herein when executed or processed by a computer.

[0062] As will be understood by those skilled in the art, aspects of the present invention may be embodied as a system, method, or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, all of which may be collectively referred to herein as a "circuit," "module," or "system." The functions described in this disclosure may be implemented as an algorithm executed by a processor / microprocessor of a computer. Further, aspects of the present invention may take the form of a computer program product embodied on one or more computer-readable media, where the one or more computer-readable media may have computer-readable program code embodied thereon, e.g., stored thereon.

[0063] Any combination of one or more computer-readable media may be utilized. The computer-readable media may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium may include, but are not limited to, an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of the present invention, the computer-readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0064] As a computer-readable signal medium, for example, a propagated data signal having computer-readable program code embodied therein, either in baseband or as part of a carrier wave, can be cited. Such a propagated signal may take any of a variety of forms, including, but not limited to, electromagnetic, optical, or any suitable combination thereof. The computer-readable signal medium may be any computer-readable medium that can communicate, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device, and is not a computer-readable storage medium.

[0065] Program code embodied on a computer-readable medium may be transmitted using any appropriate medium including, but not limited to, wireless, wired, fiber optic, cable, RF, etc., or any suitable combination of the foregoing. The computer program code for performing the operations regarding the aspects of the present invention may be written in any combination of one or more programming languages including object-oriented programming languages such as Java (trademark), Smalltalk, C++, etc., and conventional procedural programming languages such as the "C" programming language or similar programming languages. This program code may be executed entirely on the user's computer as a stand-alone software package, partially on the user's computer, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network including a local area network (LAN) or a wide area network (WAN), or this connection may be implemented to an external computer (e.g., through the Internet using an Internet service provider).

[0066] Aspects of the present invention will be described below with reference to the flowchart diagrams and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart diagrams and / or block diagrams, and combinations of blocks in the flowchart diagrams and / or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor, particularly a microprocessor or a central processing unit (CPU) of a general purpose computer, a special purpose computer, or other programmable data processing apparatus to create a machine, such that the instructions executed via the processor of the computer, other programmable data processing apparatus, or other device create means for implementing the functions / acts specified in the blocks of the flowchart and / or block diagram.

[0067] These computer program instructions may also be stored in a computer-readable medium that can direct a computer, other programmable data processing apparatus, or other device to function in a particular manner, such that the instructions stored in the computer-readable medium create a product including instructions for implementing the functions / acts specified in the blocks of the flowchart and / or block diagram.

[0068] The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to create a computer-implemented process, such that the instructions executed on the computer or other programmable apparatus provide a process for implementing the functions / acts specified in the blocks of the flowchart and / or block diagram.

[0069] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, segment, or portion of code that includes one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions noted in the blocks may be performed in an order different from that noted in those figures. For example, two blocks shown in succession may, in fact, be executed substantially simultaneously, or the blocks may be executed in the reverse order, depending on the functionality involved. Also, each block of the block diagrams and / or flowchart diagrams, and combinations of blocks in those block diagrams and / or flowchart diagrams, can be implemented by a dedicated hardware-based system that performs the specified function or act, or by a combination of dedicated hardware and computer instructions.

[0070] Furthermore, a computer program for practicing the methods described herein, and a non-transitory computer-readable storage medium storing the computer program are provided. The computer program may, for example, be downloaded (uploaded) to an existing system, or may be stored at the time of manufacture of these systems.

[0071] Elements and aspects discussed in connection with a particular embodiment or in relation to a particular embodiment may be combined with elements and aspects of other embodiments as appropriate, unless otherwise expressly stated. Embodiments of the present invention are further illustrated with reference to the accompanying drawings, which schematically depict embodiments of the present invention. It should be understood that the present invention is in no way limited to these specific embodiments.

Brief Description of the Drawings

[0072] Aspects of the present invention will be described in more detail with reference to the illustrative embodiments shown in the drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6

Figure 7

Figure 8

Figure 9

Best Mode for Carrying Out the Invention

[0073] In the figures, the same reference numerals refer to the same or similar elements.

[0074] FIG. 1 shows a system according to one embodiment for illuminating one or more plants with artificial light 4. The lighting system includes a lighting device 2 configured to generate artificial light 4 having a plurality of artificial light components. Each of the artificial light components is of a respective wavelength or wavelength range. Further, the lighting device 2 can adjust the irradiance of each light component separately. Typically, the lighting device includes a plurality of separately controllable light sources, at least some of which emit different light colors. The system also includes a control system 100, also referred to herein as a data processing system, configured to execute any of the methods described herein. The control system 100 is preferably configured to send control signals to different light sources of the lighting device 2, such as LEDs, and to receive signals from sensors that may be present near the plants.

[0075] FIG. 1A shows that one or more plants 6 can receive both artificial light 4 and sunlight 10. For example, when the EM spectrum of sunlight changes such that one sunlight component, such as red light, becomes relatively strong compared to other light components, it may be desirable to dim only the corresponding artificial light component, such as the red light component, of the artificial light. This ensures that one or more plants receive light of an appropriate EM spectrum at any given time. Note that the notion of an appropriate EM spectrum may depend on various factors. In any case, it should be understood that the desired EM spectrum can change over time.

[0076] This is shown, for example, by FIG. 2. FIG. 2 shows two graphs for two respective times, referred to as T1 and T2. These times may be, for example, several hours apart. In this case, T1 may refer to daytime hours and T2 may refer to twilight hours. The vertical axis of the graph represents irradiance and the horizontal axis represents wavelength. Each graph may be understood to depict a wavelength range from blue-green light on the left to red light on the right. In particular, the first wavelength range may be 400-500 nm and the second wavelength range may be 600-700 nm.

[0077] Each graph shows a so-called desired illumination spectrum for one or more plants, as indicated by the dashed line. FIG. 2 shows that the desired illumination spectrum can change over time. The desired illumination spectrum defines, for T1, a first predefined value for the indicated first wavelength range and a second predefined value for the second wavelength range, and for T2, a third predefined value for the indicated first wavelength range and a fourth predefined value for the second wavelength range. It should be noted that a full desired EM spectrum need not be defined for one or more plants. The predefined values may be defined for a selected number of wavelengths or wavelength ranges.

[0078] Furthermore, each graph shows the EM spectrum of sunlight incident on one or more plants at that time. Note that at T1, during the day, the sunlight spectrum includes a relatively strong blue / green sunlight component, while at T2, at dusk, the sunlight spectrum includes a relatively weak blue / green sunlight component. In particular, at T1, the first sunlight component in the first wavelength range has an irradiance of E, also referred to herein as the "fifth irradiance value". e5 The second sunlight component in the second wavelength range has an irradiance of E, also referred to herein as the "sixth irradiance value". e6 At T2, the first sunlight component has an irradiance of E, also referred to herein as the "seventh irradiance value". e7 The second sunlight component has an irradiance of E, also referred to herein as the "eighth irradiance value". e8 At T1, to enable one or more plants to receive a desired EM spectrum, the artificial light includes a first artificial light component in the first wavelength range having an irradiance of E, also referred to herein as the "first irradiance value", and a second artificial light component in the second wavelength range having an irradiance of E, also referred to herein as the "second irradiance value". As a result, at T1, the one or more plants receive, in total, light in the first wavelength range having a first predetermined irradiance value and light in the second wavelength range having a second predetermined irradiance value. Similarly, at T2, the artificial light includes light in the first wavelength range having an irradiance of E, also referred to herein as the "third irradiance value", and light in the second wavelength range having an irradiance of E, also referred to herein as the "fourth irradiance value". The irradiance value for the artificial light component can be determined for each light component based on the difference between the predetermined irradiance value and the irradiance value already provided by sunlight.

[0079] At T1, to enable one or more plants to receive a desired EM spectrum, the artificial light includes a first artificial light component in the first wavelength range having an irradiance of E, also referred to herein as the "first irradiance value". e1 And a second artificial light component in the second wavelength range having an irradiance of E, also referred to herein as the "second irradiance value". e2 As a result, at T1, the one or more plants receive, in total, light in the first wavelength range having a first predetermined irradiance value and light in the second wavelength range having a second predetermined irradiance value. Similarly, at T2, the artificial light includes light in the first wavelength range having an irradiance of E, also referred to herein as the "third irradiance value". e3 And light in the second wavelength range having an irradiance of E, also referred to herein as the "fourth irradiance value". e4 The irradiance value for the artificial light component can be determined for each light component based on the difference between the predetermined irradiance value and the irradiance value already provided by sunlight.

[0080] Figure 2 shows the ratio E e1 / E e2 which is different from the ratio E e3 / E e4 and shows that the ratio E e1 / E e3 is different from the ratio E e2 / E e4 These differences in the ratios indicate that different artificial light components are controlled separately.

[0081] Furthermore, for example, assuming that T2 is dusk and T1 is daytime, the total irradiance of sunlight at T2 is lower than that at T1, the ratio E e1 / E e3 is found to be smaller than the ratio E e2 / E e4 The irradiance of the first artificial light component is increased profoundly more than that of the second artificial light component.

[0082] It should be understood that Figure 2 merely shows an example of a darkening situation. However, the method and system can of course also be used when the situation brightens, for example when the sun rises.

[0083] The graph in Figure 3 contains the same information as the graph in Figure 2, but the graph shows the artificial light spectrum (see dashed-dotted line) more clearly.

[0084] As is apparent from the above, the system preferably knows the EM spectrum of sunlight incident on one or more plants at any given point in time. This enables, that is, accurately determining the irradiance values for each artificial light component so that the one or more plants receive the appropriate EM spectrum in total.

[0085] For this purpose, as depicted in Figure 1B, the system may include a sensor 8 for measuring at least two irradiance values for two respective wavelengths or wavelength ranges of sunlight 10 incident on one or more plants, or an EM spectrum. It should be noted that this sensor 8 is preferably positioned so as not to receive the artificial light 4 generated by the lighting device 2. Based on the measured EM spectrum and based on the desired EM spectrum, an appropriate spectrum for the artificial light can be determined.

[0086] It should be understood that the sensor 8 is not necessarily configured to measure spectrally resolved irradiance values, i.e., at least two separate irradiance values for at least two respective wavelengths or wavelength ranges. For example, the sensor 8 may be configured to measure (simply) non-spectrally resolved irradiance values, for example, the total irradiance of sunlight incident on one or more plants. The sensor 8 may transmit a signal indicating this total irradiance value to the control system 100. The controller 100 can determine an appropriate irradiance value for the artificial light component based on this total irradiance value.

[0087] For example, the control system 100 may store each total irradiance value of sunlight in association with a set of respective irradiance values, where each set may include an irradiance value for a first sunlight component of a first wavelength or wavelength range and an irradiance value for a second sunlight component of a second wavelength or wavelength range. For example, the control system 100 may have sunlight reference data indicating the respective EM spectra of sunlight for each total irradiance value of sunlight, for example. Based on this, the control system can determine the current EM spectrum of sunlight, and then, based on the determined EM spectrum of sunlight, determine an appropriate spectrum for the artificial light so that one or more plants receive the desired EM spectrum.

[0088] Figure 1C shows yet another embodiment of the system. Here, the sensor 8 is positioned to receive both sunlight 10 and artificial light generated by the lighting device 2. In this embodiment, preferably, the sensor 8 is configured to measure the respective irradiance values for each light component. The sensor 8 is preferably configured to measure the EM spectrum received by one or more plants. Note that both sunlight 10 and artificial light 4 contribute to the EM spectrum received by one or more plants.

[0089] Such a setup enables implementing a feedback loop as described with reference to Figure 4. That is, the sensor 8 may continuously measure the EM spectrum incident on one or more plants and feedback this EM spectrum to the control system 100. The control system 100 may monitor whether each light component is at a predetermined level. For a particular light component, if the irradiance value is below a predetermined value, the control system 100 may control the lighting system to increase the irradiance for that light component until the control system 100 receives again from the sensor 8 a signal indicating that the irradiance value for that light component is at a predetermined level. For a particular light component, if the irradiance value is above a predetermined value, the control system 100 may control the lighting system to decrease (dim) the irradiance for that light component until the control system 100 receives again from the sensor 8 a signal indicating that the irradiance value for that light component is at a predetermined level.

[0090] Figure 4 shows the situation at two times, T1 - δ and T2 - δ. Here, delta may be relatively small, for example, a few seconds, but this depends on how responsive the system should be.

[0091] In any case, at T1-δ, the sensor 8 measures the total irradiance value for a first light component lower than a predetermined value and the total irradiance value for a second light component higher than a predetermined value. After the control system 100 receives a signal indicating this from the sensor 8, the control system 100 increases the irradiance value of the first light component in the artificial light and decreases the irradiance value of the second light component in the artificial light, and monitors (using the feedback loop again) when the irradiance values reach their respective predetermined levels (as shown in FIG. 2), thereby determining appropriate irradiance values for the light components.

[0092] At T2-δ, the irradiance value of the first light component is too high and the irradiance value of the second light component is too low. The correct values can be determined in the same manner as described for the case of T1-δ.

[0093] FIG. 5A is a table showing separately controllable channels (Channel 1, 2, 3) for one embodiment of the lighting system. Such a system may be based on a single lighting device having three different channels, or on three different lighting devices considering each lighting device as a separate channel, or a combination thereof. The lighting device may be a luminaire.

[0094] In this embodiment, Channel 1 generates blue light, Channel 2 generates white light, and Channel 3 generates red light. White light typically consists of a combination of B, G, R, and a very small amount of FR (far red light). Far red light may be understood as light having a wavelength of 700 to 800 nm.

[0095] Typically, the energy efficiency (more precisely, the efficacy) of these channels is different. Generally, to generate 1 mole of photons, the red channel (Channel 3) requires the least amount of energy, and thus the red channel typically has the highest efficacy among the channels. The white channel typically has a lower efficacy.

[0096] Figure 5B shows, for reference, the composition of daylight and white light. Here, PAR is the so-called photosynthetically active radiation (expressed in μmol / s / m 2 ), which is the sum of all radiation in the B, G, and R wavelength bands.

[0097] The following general principles regarding supplementary lighting may be implemented: · In the case of supplementary lighting for greenhouse horticulture, the supplementary light is preferably provided at times when the daylight level is low. That is, the photosynthesis process shows a linear relationship with the light level for low light levels. When the light level is increased, at a certain point, photosynthesis saturates. When saturation occurs, the light use efficiency (LUE) decreases, which is undesirable. Therefore, a good supplementary light level is related to the daylight level: the lower the daylight level, the higher the supplementary light level can be, and vice versa. · There is an optimal integral amount of light (the so-called daily light integral (DLI)) for any crop, which is a compromise between biomass or fruit production and LUE (in the case of tomatoes, the desired DLI is typically 15 mol / m 2 / day). · Most crops require a period of darkness. In the case of tomatoes, this dark period should be at least 6 hours. If this rule is not followed, crop defects occur. · Plants require a certain minimum fraction of blue light in the spectrum of the light provided, especially to ensure the opening of stomata for CO 2 absorption. · LUE is highest for red light, followed by blue light, white light (or green light).

[0098] With these principles in mind, the daily supplemental light profile may appear as depicted by the solid line in FIG. 6 (vertical axis: Overall supplemental light output, horizontal axis: Time of day). Assume that the producer anticipates that a dimming level of 80% is sufficient to reach the desired DLI. In this example, the supplemental light is turned on at 5 o'clock at a dimming level of 80%. As the daylight level increases, the supplemental light level is gradually decreased. At the end of the daylight period, since it becomes clear that an 80% dimming level is insufficient to reach the desired DLI, the supplemental light level is gradually increased to 100% at the end of the daylight period. The supplemental lighting is turned off at 23:00 to ensure that the plants receive a sufficient duration of dark period.

[0099] The flowchart of the foregoing steps is shown in FIG. 7. A greenhouse control computer, for example, controller 100a, may receive daylight measurements and / or user inputs. The daylight measurements may be spectrally decomposed. The user input may indicate the desired EM spectrum for one or more plants, i.e., the total EM spectrum (combination of sunlight and artificial light) that one or more plants should receive. Based on the daylight measurements and user input, the greenhouse control computer may output an overall dimming signal. Such an overall dimming signal may be regarded as a non-spectrally resolved dimming signal in that it does not indicate at least two dimming levels for at least two respective channels.

[0100] The lighting control system may determine a channel-by-channel dimming signal based on the overall dimming signal, and thus determine appropriate irradiance values for at least two artificial light components. These dimming signals for different channels may be sent to different drivers of the lighting sources so that the plants receive appropriate lighting.

[0101] FIG. 8 shows a portion of the sunlight reference data according to one embodiment. Each row includes a Non-spectrally resolved irradiance value, which in this example is in the range of 50 / 100 to 90 / 100. Further, each non-spectrally resolved irradiance value is associated with the reference EM spectrum of sunlight (see the rightmost column) (thus, the reference EM spectrum of sunlight shows the reference irradiance value for the first sunlight component and the reference irradiance value for the second sunlight component).

[0102] The reference non-spectrally resolved irradiance value and the associated reference sunlight EM spectrum may be measured, for example.

[0103] Furthermore, in this example, each reference irradiance value is also associated with a Month and a Time of day. In this example, each reference value is associated with the same month and the same day, namely "July" and 10:00 AM. Of course, in reality, the sunlight reference data may include more entries for more reference irradiance values, for all months, and for more times of day.

[0104] When the controller described herein receives the non-spectrally resolved irradiance value of sunlight around 10:00 AM in July, the controller can determine, based on these sunlight reference data, what EM spectrum the sunlight has, for example, by simply selecting the reference EM spectrum of the reference irradiance value that is closest to the received (measured) irradiance value as the actual EM spectrum of the sunlight. Subsequently, this makes it possible to determine the appropriate irradiance value for the artificial light component.

[0105] FIG. 9 shows a block diagram showing a data processing system according to one embodiment.

[0106] As shown in FIG. 9, data processing system 100 may include at least one processor 102 coupled to memory element 104 via system bus 106. Therefore, the data processing system may store program code within memory element 104. Further, processor 102 may execute program code accessed from memory element 104 via system bus 106. In one aspect, the data processing system may be implemented as a computer suitable for storing and / or executing program code. However, it should be understood that data processing system 100 may be implemented in any system form including a processor and memory capable of performing the functions described herein.

[0107] Memory element 104 may include one or more physical memory devices such as, for example, local memory 108 and one or more mass storage devices 110. Local memory may refer to random access memory or other non-persistent memory devices generally used during the actual execution of program code. The mass storage device may be implemented as a hard drive or other persistent data storage device. Processing system 100 may also include one or more cache memories (not shown) that provide temporary storage of at least some program code to reduce the number of times program code must be retrieved from mass storage device 110 during execution.

[0108] Input / output (I / O) devices, shown as input device 112 and output device 114, can optionally be coupled to a data processing system. Examples of input devices include, but are not limited to, keyboards, pointing devices such as mice, touch-sensitive displays, sensors described herein, control systems for greenhouse 100a, etc. Examples of output devices include, but are not limited to, monitors or displays, speakers, lighting systems described herein, etc. The input device and / or output device may be coupled to the data processing system directly or via an intervening I / O controller.

[0109] In one embodiment, the input device and output device may be implemented as a combined input / output device (shown in FIG. 9 by the dashed line surrounding input device 112 and output device 114). An example of such a combined device is a touch-sensing display, which may also be referred to as a "touch screen display" or simply a "touch screen." In such an embodiment, input to the device may be provided by the movement of a physical entity, such as a stylus or the user's finger, on or near the touch screen display.

[0110] Network adapter 116 may also be coupled to the data processing system to enable the data processing system to be coupled to other systems, computer systems, remote network devices, and / or remote storage devices via an intervening private or public network. The network adapter may include a data receiver for receiving data transmitted to the data processing system 100 by the systems, devices, and / or networks described above, and a data transmitter for transmitting data from the data processing system 100 to the systems, devices, and / or networks described above. Modems, cable modems, and Ethernet (registered trademark) cards are examples of various types of network adapters that may be used with the data processing system 500.

[0111] As shown in FIG. 9, memory element 104 may store application 118. In various embodiments, application 118 may be stored in local memory 108, in one or more mass storage devices 110, or may be separate from local memory and mass storage devices. It should be understood that data processing system 100 may further execute an operating system (not shown in FIG. 9) capable of facilitating the execution of application 118. Application 118 is implemented in the form of executable program code and can be executed by data processing system 100, for example, by processor 102. In response to the execution of the application, data processing system 100 may be configured to perform one or more operations or method steps described herein.

[0112] In one aspect of the present invention, data processing system 100 may represent control system 100 described herein.

[0113] In another aspect, the data processing system 100 may represent a client data processing system. In this case, when executed, the application 118 may represent a client application that configures the data processing system 100 to perform various functions described herein with reference to a "client". Examples of clients include, but are not limited to, personal computers, portable computers, mobile phones, and the like.

[0114] In yet another aspect, the data processing system 100 may represent a server. For example, the data processing system may represent an (HTTP) server, in which case, when executed, the application 118 may configure the data processing system to perform (HTTP) server operations.

[0115] Various embodiments of the present invention may be implemented as a program product for use with a computer system, and the program(s) of the program product may define the functions of the embodiments (including the methods described herein). In one embodiment, the program can be included on various non-transitory computer-readable storage media, and as used herein, the expression "non-transitory computer-readable storage media" includes all computer-readable media, with the sole exception being transitory propagation signals. In another embodiment, the program can be included on various transitory computer-readable storage media. Exemplary computer-readable storage media include, but are not limited to, (i) non-writable storage media on which information is permanently stored (e.g., CD-ROM disks readable by a CD-ROM drive, ROM chips, or any type of non-volatile solid semiconductor memory such as a read-only memory device inside a computer), and (ii) writable storage media on which changeable information is stored (e.g., flash memory, floppy disks inside a diskette drive or hard disk drive, or any type of random access solid semiconductor memory). The computer program may be executed on the processor 102 described herein.

[0116] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the terms "comprises" and / or "comprising" specify the presence of the described features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0117] For all means-plus-function or step-plus-function elements in the following claims, the corresponding structures, materials, acts, and equivalents are intended to include any structure, material, or act for performing the function in combination with other claimed elements that are specifically claimed. The description of embodiments of the invention has been presented for purposes of illustration but is not intended to be exhaustive or limited to the forms disclosed. Many modifications and variations will be apparent to practitioners skilled in the art without departing from the scope and spirit of the invention. The embodiments were chosen and described in order to best explain the principles of the invention and some practical applications, and to enable others skilled in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A computer-implemented method for controlling one or more lighting fixtures configured to illuminate one or more plants with artificial light, wherein the artificial light comprises a plurality of artificial light components, each of the artificial light components being of a respective wavelength or wavelength range, the plurality of artificial light components including a first artificial light component of a first wavelength or wavelength range and a second artificial light component of a second wavelength or wavelength range, the method comprising: Receiving a signal indicative of the non-spectral resolved irradiance value of sunlight incident on the one or more plants; Including, the method further comprising: Determining an irradiance value for the first artificial light component and an irradiance value for the second artificial light component based on the non-spectral resolved irradiance value; and Controlling the one or more lighting fixtures to provide the one or more plants with artificial light having the determined irradiance value for the first artificial light component and the determined irradiance value for the second artificial light component such that the one or more plants receive light of the first wavelength or wavelength range at a predetermined irradiance value for the first wavelength or wavelength range and light of the second wavelength or wavelength range at a predetermined irradiance value for the second wavelength or wavelength range; Including, The method further comprising: Storing sunlight reference data indicative of a reference irradiance value for a first sunlight component and a reference irradiance value for a second sunlight component for each of a plurality of reference non-spectral resolved irradiance values; Determining the irradiance value for the first artificial light component and determining the irradiance value for the second artificial light component based on the sunlight reference data; Including, a method.

2. The method according to claim 1, wherein receiving a signal indicative of the non-spectral resolved irradiance value includes measuring the non-spectral resolved irradiance value of sunlight incident on the one or more plants.

3. Determining the irradiance value for the first artificial light component includes determining the difference between the reference irradiance value for the first sunlight component and the predetermined irradiance value for the first wavelength or wavelength range, and / or Determining the irradiance value for the second artificial light component includes determining the difference between the reference irradiance value for the second sunlight component and the predetermined irradiance value for the second wavelength or wavelength range, the method according to claim 1 or 2.

4. The sunlight incident on the one or more plants has a first electromagnetic spectrum at a first time and a second electromagnetic spectrum at a second time after the first time, and the second electromagnetic spectrum is different from the first electromagnetic spectrum. The received signal indicates the non-spectral decomposition irradiance value of the sunlight incident on the one or more plants at the first time, and the method includes: Receiving a second signal indicating the non-spectral decomposition irradiance value of the sunlight incident on the one or more plants at the second time; Based on the second non-spectral decomposition irradiance value and the sunlight reference data, determining a reference irradiance value of the first sunlight component incident on the one or more plants at the second time, and a reference irradiance value of the second sunlight component incident on the one or more plants at the second time; Based on a predetermined irradiance value for the first wavelength or wavelength range at the second time and the determined reference irradiance value of the first sunlight component incident on the one or more plants at the second time, determining an irradiance value for the first artificial light component at the second time; Based on a predetermined irradiance value for the second wavelength or wavelength range at the second time and the determined reference irradiance value of the second sunlight component incident on the one or more plants at the second time, determining an irradiance value for the second artificial light component at the second time; Controlling the one or more lighting fixtures such that the one or more plants receive light in the first wavelength or wavelength range at a predetermined irradiance value for the first wavelength or wavelength range at the second time and light in the second wavelength or wavelength range at a predetermined irradiance value for the second wavelength or wavelength range at the second time, and providing the one or more plants with artificial light having the determined irradiance value for the first artificial light component at the second time and the determined irradiance value for the second artificial light component at the second time; The method according to any one of claims 1 to 3, comprising: Claim 5 Determining the irradiance value for the first artificial light component at the second time includes determining the difference between the reference irradiance value for the first sunlight component at the second time and the predetermined irradiance value for the first wavelength or wavelength range at the second time, and / or Determining the irradiance value for the second artificial light component at the second time includes determining the difference between the reference irradiance value for the second sunlight component at the second time and the predetermined irradiance value for the second wavelength or wavelength range at the second time, the method according to claim 4. **Claim 6** The ratio of the irradiance value for the first artificial light component at the first time to the irradiance value for the second artificial light component at the first time is different from the ratio of the irradiance value for the first artificial light component at the second time to the irradiance value for the second artificial light component at the second time, and / or The ratio of the irradiance value for the first artificial light component at the first time to the irradiance value for the first artificial light component at the second time is different from the ratio of the irradiance value for the second artificial light component at the first time to the irradiance value for the second artificial light component at the second time, the method according to claim 4 or 5. **Claim 7** The first wavelength range is 400 - 500 nm, and the second wavelength range is 600 - 700 nm, When the total irradiance of sunlight incident on the one or more plants at the second time is lower than the total irradiance of sunlight incident on the one or more plants at the first time, the ratio of the irradiance value for the first artificial light component at the first time to the irradiance value for the first artificial light component at the second time is smaller than the ratio of the irradiance value for the second artificial light component at the first time to the irradiance value for the second artificial light component at the second time, If the total irradiance of sunlight incident on the one or more plants at the second time is higher than the total irradiance of sunlight incident on the one or more plants at the first time, the ratio of the irradiance value for the first artificial light component at the first time to the irradiance value for the first artificial light component at the second time is greater than the ratio of the irradiance value for the second artificial light component at the first time to the irradiance value for the second artificial light component at the second time. The method according to any one of claims 4 to 6.

8. An input interface for receiving a signal indicating a non-spectral decomposition irradiance value, An output interface for sending irradiance values for a first artificial light component and a second artificial light component to an illumination device, A processor configured to execute the method according to any one of claims 1 to 7, a processor, A control system including.

9. An illumination system for illuminating one or more plants with artificial light, the illumination system An illumination device configured to generate artificial light having a plurality of artificial light components, each of the artificial light components being of a respective wavelength or wavelength range, and configured to adjust the irradiance of each light component separately, The control system according to claim 8, An illumination system including.

10. A computer program including instructions for causing the illumination device according to claim 9 to execute the method according to any one of claims 1 to 7.

11. A computer-readable medium storing the computer program according to claim 10.

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