Method and system for illuminating plants with artificial light

Abstract

A computer-implemented method for controlling one or more illuminators configured to illuminate one or more plants with artificial light is disclosed. The artificial light includes a plurality of artificial light components. Each artificial light component has 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. In addition, sunlight is incident on one or more plants. The sunlight includes a plurality of sunlight components. Each solar component has a respective wavelength or wavelength range. The plurality of sunlight components includes a first sunlight component of a first wavelength or range of wavelengths and a second sunlight component of a second wavelength or range of wavelengths. The method includes receiving a signal indicative of a non-spectrally resolved irradiance value of sunlight incident on one or more plants.

Description

Technical Field

[0001] The present disclosure relates to a method and system for irradiating one or more plants with artificial light. Specifically to such method and system, a signal is provided indicating a non-spectrally resolved irradiance value of at least one of:

[0002] - the sunlight incident on one or more plants,

[0003] - artificial light to be incident on one or more plants. The present disclosure also relates to a computer program and a computer readable storage medium and a controller for performing such a method. Background Art

[0004] To allow year-round production of crops such as tomatoes in greenhouses, many growers now use supplemental lighting such as LED lighting, especially during the fall, winter and spring when daylight levels (in northern countries) are often insufficient for tomato growth and tomato prices are high.

[0005] Supplementary lighting (also more generally referred to as artificial light) can be applied above the canopy of the plant (so-called top lighting) or from within the canopy of the plant (so-called interior lighting).

[0006] Plants use light as a source of energy for absorbing CO2 from the surrounding air and converting it into biomass. This process is called photosynthesis. Part of the biomass is allocated to fruit (such as tomatoes). Therefore, light is essential for the growth of plants and fruits. In modern greenhouses, environmental parameters such as climate and irrigation are well controlled, which means that the availability of light is a factor limiting growth.

[0007] The process of photosynthesis occurs primarily in response to light within a wavelength range. This range is approximately from 400-700nm. Radiation within this range is called Photosynthetically Active Radiation (PAR).

[0008] PAR light levels are measured in μmol / s / m 2 The number of photons corresponding to 1 mol of light is equal to Avogadro's number (6.0×10 23 ).

[0009] Artificial lighting in horticulture consumes energy, resulting in considerable operating costs and, in the case of electricity generated using fossil fuels, a non-negligible carbon footprint. It is therefore desirable to reduce energy consumption.

[0010] US2016 / 0088802 discloses a lighting system and method for growing plant seedlings, comprising: at least one light source for illuminating the plant seedlings with a growth light during a growth phase of the plant seedling growth process; and a controller for controlling the spectral power distribution of the growth light emitted from the light source so that the growth light in at least some growth phases of the plant seedling growth process includes more energy in the blue wavelength range than the growth light in other growth phases of the plant seedling growth process. In the use case where the growth light supplements the available sunlight, additional sensors can be used to measure the amount and spectral composition of the sunlight, and control the growth light so that the spectral power distribution of the total light received by the plant seedling is controlled accordingly.

[0011] US2015 / 0128489 discloses a plant growth system, wherein a first light source irradiates plants with light having a peak wavelength in a range from 380 to 560 nm and a peak wavelength in a range from 560 to 680 nm, and a second light source irradiates plants with far-red light having a peak wavelength in a range from 685 to 780 nm. In addition, a control unit controls the first and second light sources to perform corresponding irradiation operations, and a time setting unit sets first and second time zones in which the control unit controls the first and second light sources to perform corresponding irradiation operations. The first time zone ranges from a first predetermined time before sunset to a second predetermined time after sunset, and the second time zone starts after the first light source completes its irradiation operation.

[0012] US2018 / 0116127 relates to systems and methods for lighting plants to provide supplemental lighting to plants in addition to natural light and to improve crop yields when such supplemental lighting is used. The invention is suitable for use in horticulture in greenhouses. Summary of the invention

[0013] To this end, a computer-implemented method for controlling one or more luminaires configured to illuminate one or more plants with artificial light is disclosed. The artificial light includes multiple artificial light components. Each artificial light component has a corresponding wavelength or wavelength range. The multiple artificial light components include 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. In addition, sunlight is incident on one or more plants. The sunlight includes multiple sunlight components. Each sunlight component has a corresponding wavelength or wavelength range. The multiple sunlight components include 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 indicating a non-spectrally resolved irradiance value of sunlight incident on the one or more plants.

[0014] The method further comprises determining a first irradiance value for the first artificial light component and a second irradiance value for the second artificial light component based on the non-spectrally resolved irradiance value. The method further comprises controlling one or more luminaires such that they provide artificial light to one or more plants, the artificial light having a first irradiance value determined for the first artificial light component and a second irradiance value determined for the second artificial light component, such that the one or more plants receive light at a first wavelength or wavelength range at a first predefined irradiance value and light at a second wavelength or wavelength range at a second predefined irradiance value.

[0015] Advantageously, the method allows - in an energy efficient manner - to provide sufficient PAR for one or more plants, even when the irradiance values ​​of different light components in the sunlight vary relative to each other, or less strictly, when the shape of the EM spectrum of the sunlight varies. It is known that the EM spectrum of sunlight varies during the day. For example, during the day the EM spectrum of sunlight includes relatively strong blue and green components relative to the red light component in the sunlight, while during sunset the EM spectrum of sunlight shows relatively weak blue and green light components relative to the red light component in the sunlight. By being able to adjust the different light components of the artificial light separately, it is possible to specifically adjust each artificial light component in the artificial light in response to the changes in its corresponding light component in the sunlight as needed. Hypothetically, if during dusk only the irradiance values ​​of the blue and green light components of the sunlight will decrease, then only the blue and green artificial light components in the artificial light will need to be increased, and the red light component will not be increased, in order to maintain an acceptable PAR spectral power distribution. Any increase in the artificial red light component - which would, for example, be performed if only the total irradiance value of the artificial light could be controlled - could result in an excessively high irradiance level of the red light on one or more plants. In this case, part of the generated red artificial light component may not be used for photosynthesis and may therefore be lost. Therefore, the method allows the light utilization efficiency (LUE), usually expressed in g / mol, to be maintained at a high level. The light utilization efficiency (LUE) defines the efficiency with which vegetation converts radiant energy into biochemical energy through photosynthesis. LUE describes how effectively a plant uses incident light to grow. LUE can be calculated by dividing the dry weight of the plant by the total incident light received by the plant during the entire growing period.

[0016] The method is also advantageous in that it enables the plants to receive appropriate irradiance values ​​for the first and second wavelengths (ranges) without requiring measurement of the spectrum of sunlight incident on one or more plants and / or without requiring spectrally resolved input control signals, i.e. control signals indicating separate irradiance values ​​for separate wavelengths or wavelength ranges. Thus, the method enables the use of relatively simple irradiance sensors, such as sensors that can only measure total irradiance values ​​for a certain fixed wavelength range (e.g. PAR wavelength range or visible light wavelength range), and / or relatively simple control infrastructures, such as requiring only the irradiance value of all artificial light incident on one or more plants as control input, while at the same time ensuring that the plants receive appropriate irradiance levels for different wavelengths or wavelength ranges.

[0017] The signal can indicate the (non-spectrally resolved) total irradiance value of the incident sunlight because it indicates the irradiance value of a relatively wide (wider than the first and second wavelength ranges) wavelength range. This will generally depend on the sensor used to measure the total irradiance of the sunlight. The total irradiance value can represent the irradiance on a considerable portion of the photosynthetically active radiation (PAR) wavelength range of 400nm to 700nm. Alternatively, the total irradiance value can represent the irradiance on a considerable portion of the visible light wavelength range of about 380nm to about 750nm. In addition, the total irradiance value can represent the irradiance on a portion of the full spectrum sunlight radiation from near ultraviolet to near infrared (i.e., from about 300nm to about 1400nm), and is considered useful for plant and animal life. This relatively wide 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 wide wavelength range may include wavelengths that are not within the first wavelength range and are not within the second wavelength range.

[0018] Preferably, the signal indicates the total irradiance value of sunlight incident on one or more plants just before the first time or the second time. In one embodiment, the signal indicating the current total irradiance value of sunlight is received repeatedly (e.g., 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 at any time (also within the first time and the second time).

[0019] Of course, based on the indicated total irradiance value of the sunlight, more irradiance values ​​may be determined for correspondingly more wavelengths or wavelength ranges.

[0020] The light received by the one or more plants is a combination of sunlight and artificial light. Thus, light of a first wavelength or wavelength range provided at a first predefined irradiance value may be understood as the first irradiance value of the first artificial light component plus the irradiance value of the first sunlight component being equal to the first predefined irradiance value.

[0021] Preferably, the non-spectrally resolved irradiance value is one total irradiance value for one or more wavelength ranges.Preferably, the signal indicates one and only one irradiance value.

[0022] Preferably, the signal does not comprise spectrally resolved data and therefore 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.

[0023] Determining the first irradiance value of the first artificial light component and the second irradiance value of the second artificial light component may be performed by determining a suitable electromagnetic (EM) spectrum of the artificial light. By definition, determining the EM spectrum may be understood as involving determining individual irradiance values ​​for individual light components.

[0024] The first and second predefined irradiance values ​​may be the same or different. A light recipe may be defined for one or more plants, the light recipe defining for each of a plurality of times an EM spectrum that the one or more plants should receive. Such a light recipe may be determined based on various factors, such as based on the species of plant and / or the age / life stage of the plant and / or based on the time of year (e.g., season) at which the plant is illuminated, the time of day and / or based on the amount of light (number of photons) received during a previous time period (e.g., the last two days) and / or based on the amount of light (number of photons) that the one or more plants are predicted to receive, e.g., in the next two days. Of course, as described above, the desired EM spectrum may be the same at the first time and the second time.

[0025] Controlling one or more luminaires may include adjusting the respective irradiances of different artificial light components, respectively. This may be performed by sending a respective control signal to each of a plurality of luminaires, wherein each luminaire is configured to generate a respective artificial light component. For illustration, a first luminaire may be a green LED, a second luminaire may be a blue LED, and a third luminaire may be a red LED. By sending different control signals to these different LEDs, the composition (EM spectrum) of the artificial light may be appropriately controlled with respect to at least 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, separate adjustments of the irradiances of the respective light components may be performed by separately controlling the respective color channels of the lighting system. The luminaire may include a type of luminaire configured to generate one artificial light component, or the luminaire may include a plurality of different types of luminaires, each of which is configured to generate a different artificial light component.

[0026] It should be appreciated that a light component as used herein may refer to a wavelength range. This may be understood as a light component including only light having a wavelength within the range and excluding light having a wavelength outside the range. Light components of artificial light may be understood as having non-overlapping wavelengths and / or non-overlapping wavelength ranges. Alternatively, light components of artificial light may have overlapping wavelength ranges. In any case, if a light component has 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.

[0027] As used herein, "irradiance" is the intensity of the radiation (which can be expressed in μmol / s / m 2 The flux density expressed in Watts per square meter at plant level (e.g., leaves) (expressed in units of watts per square meter). Typically, adjusting the irradiance of an artificial light component incident on one or more plants is performed by adjusting the "radiant flux" of the artificial light component as generated by a lighting device. The radiant flux can be expressed in units of Watts. For a particular setting of one or more plants and a lighting device, the irradiance of the artificial light component incident on the one or more plants is associated with the radiant flux of the artificial light component generated by the lighting device. This relationship between radiant flux and irradiance can be determined in a direct manner, for example by simply setting the radiant flux for the artificial light component from the lighting device at a corresponding radiant flux value, and for each value, measuring the irradiance value at the one or more plants. In view of the above, determining an irradiance value may also refer to determining a corresponding radiant flux value that the lighting device should generate. Similarly, adjusting the irradiance of a light component incident on one or more plants may also refer to adjusting the radiant flux of the light component as generated by the lighting device.

[0028] In this disclosure, and unless otherwise indicated, the following definitions will be used:

[0029] “first irradiance value” refers to the irradiance value of a first artificial light component of a first wavelength or wavelength range at a first time;

[0030] “second irradiance value” refers to the irradiance value of a second artificial light component at a second wavelength or wavelength range at a first time;

[0031] “third irradiance value” refers to the irradiance value of the first artificial light component of the first wavelength or wavelength range at the second time;

[0032] “fourth irradiance value” refers to the irradiance value of the second artificial light component at the second wavelength or wavelength range at the second time;

[0033] “fifth irradiance value” refers to the irradiance value of the first sunlight component of the first wavelength or wavelength range at the first time;

[0034] “sixth irradiance value” refers to the irradiance value of a second sunlight component of a second wavelength or wavelength range at a first time;

[0035] “the seventh irradiance value” refers to the irradiance value of the first sunlight component of the first wavelength or wavelength range at the second time;

[0036] “an eighth irradiance value” refers to the irradiance value of a second sunlight component of a second wavelength or wavelength range at a second time;

[0037] "first predetermined irradiance value" means a predetermined irradiance value at a first wavelength or wavelength range at a first time;

[0038] "second predetermined irradiance value" means a predetermined irradiance value at a second wavelength or wavelength range at a first time;

[0039] “third predetermined irradiance value” refers to the predetermined irradiance value of the first wavelength or wavelength range at the second time;

[0040] "Fourth predetermined irradiance value" refers to a predetermined irradiance value at a second wavelength or wavelength range at a second time.

[0041] In one embodiment, the non-spectrally resolved irradiance value is an irradiance value of sunlight incident on one or more plants. In such an embodiment, determining the first and second irradiance values ​​may include:

[0042] - determining a fifth irradiance value of a first sunlight component incident on the one or more plants based on the non-spectrally resolved irradiance value, the first sunlight component having a first wavelength or wavelength range, and determining a sixth irradiance value of a second sunlight component incident on the one or more plants, the second sunlight component having a second wavelength or wavelength range, and

[0043] - determining a first irradiance value of the first artificial light component based on a first predefined irradiance value of the first wavelength or wavelength range and based on a fifth irradiance value of the first sunlight component, and

[0044] - determining a second irradiance value for the second artificial light component based on a second predefined irradiance value for the second wavelength or wavelength range and based on the determined sixth irradiance value for the second sunlight component.

[0045] In this embodiment, a relatively simple light sensor can be used that can only measure a non-spectrally resolved sunlight irradiance value. This single irradiance value is sufficient to determine the irradiance values ​​of the first and second sunlight components, respectively, as further described below. In one example, the complete EM spectrum of sunlight incident on one or more plants can be determined based on the single non-spectrally resolved irradiance value.

[0046] In a preferred embodiment, the first irradiance value is the difference between the first predefined irradiance value and the fifth irradiance value, and similarly, the second irradiance value is the difference between the second predefined irradiance value and the sixth irradiance value. Thus, determining the first and second irradiance values ​​of the first and second artificial light components may include determining the difference between the first and second predefined irradiance values ​​and the first and second irradiance values ​​of the first and second sunlight components. Thus, in one example, the method may include determining that the first sunlight component is not strong enough to provide the first predefined irradiance value for one or more plants, as a result of which the irradiance value of the first artificial light component may be increased.

[0047] In one embodiment, the method comprises storing sunlight reference data indicating, for each of a plurality of reference non-spectrally resolved irradiance values, a reference irradiance value of the first sunlight component and a reference irradiance value of the second sunlight component. In this context, 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.

[0048] For each reference non-spectrally resolved irradiance value, the sunlight reference data may indicate a time of day and / or a time of year (preferably a date).The irradiance values ​​of the first sunlight component and the second sunlight component may then be determined based on the current time of day and / or the current time of year and based on the reference data.

[0049] In one example, for each pre-stored non-spectrally resolved (e.g., total) irradiance value of sunlight, the complete EM spectrum of the sunlight is stored. Based on this EM spectrum and based on the predefined irradiance values, an appropriate irradiance value for the corresponding artificial light component can be determined, for example by determining the difference between the EM spectrum of the sunlight and the predefined EM spectrum that should be incident on one or more plants.

[0050] The non-spectrally resolved irradiance values ​​of sunlight can be stored in association with the respective sets of irradiance values ​​of the sunlight components of the sunlight, because a first relationship is stored between the total irradiance of the sunlight and the irradiance of the first sunlight component, and a second relationship is stored between the total irradiance of the sunlight and the irradiance of the second sunlight component. Based on these relationships and given the non-spectrally resolved irradiance values ​​of sunlight, the irradiance value of the first sunlight component and the irradiance value of the second sunlight component can be calculated.

[0051] The sunlight reference data may include estimated, calibrated, or measured values ​​of various sunlight components associated with reference non-spectrally resolved sunlight irradiance values.

[0052] 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 a non-spectrally resolved irradiance value of the sunlight incident on the one or more plants at the first time. In addition, the embodiment includes receiving a second signal indicating a non-spectrally resolved irradiance value of the sunlight incident on the one or more plants at the second time. The embodiment also includes determining a seventh irradiance value of the first sunlight component incident on the one or more plants based on the second non-spectrally resolved irradiance value, and an eighth irradiance value of the second sunlight component incident on the one or more plants. The embodiment also includes determining a third irradiance value of the first artificial light component based on a third predefined irradiance value of the first wavelength or wavelength range and based on the determined seventh irradiance value of the first sunlight component, and determining a fourth irradiance value of the second artificial light component based on a fourth predefined irradiance value of the second wavelength or wavelength range and based on the determined eighth irradiance value of the second sunlight component. One or more luminaires can then be controlled so that they provide artificial light to one or more plants, the artificial light having a third irradiance value determined for the first artificial light component and a fourth irradiance value determined for the second artificial light component, so that the one or more plants receive light at a first wavelength or wavelength range at the third predefined irradiance value and light at a second wavelength or wavelength range at the fourth predefined irradiance value at a second time.

[0053] This embodiment allows for spectrally selective modulation of artificial light so that at any given time and under fluctuations in sunlight non-spectrally resolved irradiance and / or sunlight EM spectrum, one or more plants receive appropriate horticultural light.

[0054] The first and second predefined irradiance values ​​may be specifically defined within the first time. The third and fourth predefined values ​​may be specifically defined within the second time.

[0055] The third predefined value may be equal to the first predefined value. Likewise, the fourth predefined value may be equal to the second predefined value. This may be the case, for example, if the light recipe has not changed between the first time and the second time.

[0056] It will be appreciated that, for any given time, more predefined irradiance values ​​may be defined for more wavelengths or ranges, respectively. For example, for any given time, a complete EM spectrum may be defined that one or more plants should receive.

[0057] Preferably, the first irradiance value and the fifth irradiance value determined in the first time are added together to form a first predefined irradiance value. Similarly, preferably, the second irradiance value and the sixth irradiance value are added together to form a second predefined irradiance value. Similarly, preferably, the third irradiance value and the seventh irradiance value are added together to form a third predefined irradiance value. Similarly, preferably, the fourth irradiance value and the eighth irradiance value are added together to form a fourth predefined irradiance value.

[0058] In one embodiment, the ratio E between the first irradiance value and the second irradiance value is e1 / E e2 Different from the ratio E between the third irradiance value and the fourth irradiance value e3 / E e4 Additionally or alternatively, the ratio E between the first irradiance value and the third irradiance value e1 / E e3 Different from the ratio E between the second irradiance value and the fourth irradiance value e2 / E e4 .

[0059] In this embodiment, the irradiance values ​​of the first and second artificial light components are adjusted relative to each other, which enables an appropriate irradiance value to be provided for each artificial light component at any given time, so that no artificial light is wasted in the sense that one or more plants receive a higher irradiance value than the defined / required irradiance value.

[0060] In one embodiment, the first wavelength range is between 400-500nm (blue), and the second wavelength range is between 600-700nm (red). In another embodiment, the first wavelength range is between 600-700nm (red), and the second wavelength range is between 700-800nm ​​(far red). In such an embodiment, for non-spectrally resolved sunlight irradiance values, the total irradiance of sunlight incident on one or more plants at the second time may be lower or higher than the total irradiance of sunlight incident on one or more plants at the first time, respectively. In this case, preferably, the ratio E between the first irradiance value and the third irradiance value is e1 / E e3 is less than or greater than the ratio E between the second irradiance value and the fourth irradiance value, respectively. e2 / E e4 .

[0061] Preferably, if the fifth irradiance value E e5 is lower than the first predefined irradiance value, then the first irradiance value E e1is non-zero and is selected such that the one or more plants receive light of the first wavelength or wavelength range at the first predefined irradiance value at the first time. Preferably, if the fifth irradiance value E e5 is equal to or higher than the first predefined irradiance value, then the first irradiance value E e1 Basically zero.

[0062] Preferably, if the sixth irradiance value E e6 is lower than the second predefined irradiance value, then the second irradiance value E e2 is non-zero and is selected such that the one or more plants receive in total at the first time light having a second wavelength or wavelength range at a second predefined irradiance value. Preferably, if the sixth irradiance value E e6 is equal to or higher than the second predefined irradiance value, then the second irradiance value E e2 Basically zero.

[0063] Preferably, if the seventh irradiance value E e7 is lower than the third predefined irradiance value, then the third irradiance value E e3 is non-zero and is selected such that the one or more plants receive, in total, light having the first wavelength or wavelength range at the third predefined irradiance value at the second time. Preferably, if the seventh irradiance value E e7 is equal to or higher than the third predefined irradiance value, then the third irradiance value E e3 Basically zero.

[0064] Preferably, if the eighth irradiance value E e8 is lower than the fourth predefined irradiance value, then the fourth irradiance value E e4 is non-zero and is selected such that the one or more plants receive, in total, light having a second wavelength or wavelength range at a fourth predefined irradiance value at a second time. Preferably, if the eighth irradiance value E e8 is equal to or higher than the fourth predefined irradiance value, then the fourth irradiance value E e4 Basically zero.

[0065] These embodiments ensure that no artificial light is wasted.

[0066] In one embodiment, the first irradiance value E is determined e1 Including determining the fifth irradiance value E e5 and a first predefined irradiance value; and / or

[0067] Determine the second irradiance value E e2 Including determining the sixth irradiance value E e6 and a second predefined irradiance value; and / or

[0068] Determine the third irradiance value E e3 Including determining the seventh irradiance value E e7 and a third predefined irradiance value; and / or

[0069] Determine the fourth irradiance value E e4 Including determining the eighth irradiance value E e8 and a fourth predefined irradiance value.

[0070] In one embodiment, the method includes determining (eg, measuring) a first total irradiance value E for a first wavelength or wavelength range as received by one or more plants at a first time. total1 , and based on the first total irradiance value E total1 Based on the first predefined irradiance value, controlling the first irradiance value E at the first time e1 the irradiance of the first artificial light component incident on the one or more plants; and / or

[0071] Determine (e.g. measure) a second total irradiance value E for a second wavelength or wavelength range as received by the one or more plants at the first time total2 , and based on the second total irradiance value E total2 Based on the second predefined irradiance value, controlling the first time to be at the second irradiance value E e2 the irradiance of the second artificial light component incident on the one or more plants; and / or

[0072] Determine (e.g. measure) a third total irradiance value E for the first wavelength or wavelength range as received by the one or more plants at a second time total3 , and based on the third total irradiance value E total3 Based on the third predefined irradiance value, controlling the third irradiance value E at the second time e4 the irradiance of the first artificial light component incident on the one or more plants; and / or

[0073] Determine (eg measure) a fourth total irradiance value E for the second wavelength or wavelength range as received by the one or more plants at the second time total4 , and based on the fourth total irradiance value E total4 Based on the fourth predefined irradiance value, controlling the fourth irradiance value E at the second time e4 The irradiance of the second artificial light component incident on the one or more plants.

[0074] Measuring total irradiance values ​​as received by one or more plants at a certain time can be performed by positioning an irradiance sensor at the plant so that the sensor receives both artificial light and sunlight. Preferably, these total irradiance values ​​are measured just before a first time and just before a second time. These measurements can be performed repeatedly, for example, every second, so that the artificial light can be appropriately adjusted at any time, for example adjusted so that the artificial light has an appropriate EM spectrum at the first and / or second time.

[0075] In this embodiment, the method may include determining a total irradiance value (such as E total1 、E total2 、E total3 、E total4 ) and a predefined irradiance value (such as the first, second, third, fourth predefined irradiance values, respectively). Based on this difference, the EM spectrum of the artificial light can be appropriately adjusted.

[0076] One aspect of the present disclosure relates to a lighting system for illuminating one or more plants with artificial light, the lighting system comprising:

[0077] - a lighting device configured to generate artificial light having a plurality of artificial light components, each artificial light component having a respective wavelength or wavelength range, and configured to individually adjust the irradiance of the respective light components, and

[0078] - A control system comprising a processor configured to perform a method according to any of the preceding claims using a lighting device.

[0079] The lighting device may include multiple lighting sources adapted to generate artificial light having multiple artificial light components. The multiple lighting sources do not need to correspond one-to-one to the multiple artificial light components. For example, the lighting device includes a blue lighting source, a red lighting source, and a white lighting source, and artificial light in the red wavelength range may be provided by using only the red and white lighting sources.

[0080] One aspect of the present disclosure relates to a control system comprising: an input interface for receiving a signal indicating a non-spectrally resolved irradiance value; an output interface for sending the irradiance value of a first artificial light component and the irradiance value of a second artificial light component to a lighting device; and a processor, wherein the processor is configured to perform any one of the methods described herein.

[0081] One aspect of the present disclosure relates to a computer program comprising instructions for causing any of the lighting systems described herein to perform any of the methods described herein.

[0082] One aspect of the present disclosure relates to a computer readable medium having stored thereon any one of the computer programs described herein.

[0083] One aspect of the present disclosure relates to a controller comprising a processor configured to perform any of the methods described herein.

[0084] One aspect of the present disclosure relates to a computer comprising a computer-readable storage medium embodying a computer-readable program code, 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 perform any one of the methods described herein.

[0085] One aspect of the present disclosure relates to a computer program or a computer program suite comprising at least one software code portion, or a computer program product storing at least one software code portion, which when run on a computer system is configured to perform any one of the methods described herein.

[0086] One aspect of the present disclosure relates to a non-transitory computer-readable storage medium storing at least one software code portion which, when executed or processed by a computer, is configured to perform any one of the methods described herein.

[0087] As will be appreciated by those skilled in the art, aspects of the present invention may be embodied as systems, methods or computer program products. Therefore, aspects of the present invention may take the form of a complete hardware embodiment, a complete software embodiment (including firmware, resident software, microcode, etc.) or an embodiment of a combination of software and hardware aspects, which may be generally referred to herein as a "circuit", "module" or "system". The functions described in this disclosure may be implemented as algorithms executed by a processor / microprocessor of a computer. In addition, aspects of the present invention may take the form of a computer program product embodied in one or more computer-readable media having a computer-readable program code embodied thereon (e.g., stored).

[0088] Any combination of one or more computer-readable media may be utilized. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or apparatus, or any suitable combination of the foregoing. More specific examples of computer-readable storage media may include, but are not limited to, the following: an electrical connection with one or more wires, a portable computer disk, 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 disk 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, a computer-readable storage medium may be any tangible medium that may contain or store a program used by or in conjunction with an instruction execution system, device, or apparatus.

[0089] A computer readable signal medium may include a propagated data signal having a computer readable program code embodied therein (e.g., in baseband or as part of a carrier wave). Such propagated signals may take any of a variety of forms, including but not limited to electromagnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that may communicate, propagate, or transport a program used by or in conjunction with an instruction execution system, apparatus, or device.

[0090] The program code embodied on a computer-readable medium can be transmitted using any suitable medium (including but not limited to wireless, wired, optical fiber, cable, RF, etc., or any suitable combination thereof). The computer program code for implementing the operation of aspects of the present invention can be written in any combination of one or more programming languages, which include object-oriented programming languages ​​(such as Java (TM), Smalltalk, or C++, etc.) and conventional procedural programming languages ​​(such as "C" programming languages ​​or similar programming languages). The program code can be executed completely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, or executed completely on a remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer by any type of network (including a local area network (LAN) or a wide area network (WAN)), or can be connected to an external computer (for example, by using the Internet of an Internet service provider).

[0091] Aspects of the present invention are described below with reference to the flowchart illustration and / or block diagram of the method, device (system) and computer program product according to an embodiment of the present invention. It will be understood that each frame of the flowchart and / or block diagram and the combination of the frames in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can 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 device to produce a machine, so that the instructions executed by the processor of the computer, other programmable data processing devices or other equipment create a device for implementing the function / action specified in the flowchart and / or one or more block diagram frames.

[0092] These computer program instructions may also be stored in a computer-readable medium, which may direct a computer, other programmable data processing apparatus, or other device to operate in a particular manner so that the instructions stored in the computer-readable medium produce an article of manufacture, which includes instructions for implementing the functions / actions specified in the flowchart and / or one or more block diagram boxes.

[0093] The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operating steps to be performed on the computer, other programmable apparatus, or other device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable apparatus provide a process for implementing the functions / actions specified in the flowchart and / or one or more block diagram blocks.

[0094] The flow chart and block diagram in each figure illustrate the architecture, function and operation of the possible implementation of the system, method and computer program product according to various embodiments of the present invention.In this regard, each frame in the flow chart or block diagram can represent a module, segment or part of the code, which includes one or more executable instructions for implementing the specified (multiple) logical functions.It should also be noted that in some alternative embodiments, the functions described in the frame may not appear in the order described in the figure.For example, the two frames shown in succession can in fact be performed substantially simultaneously, or sometimes these frames can be performed in reverse order, depending on the functions involved.It will also be noted that each frame of the block diagram and / or flow chart and the combination of frames in the block diagram and / or flow chart can be implemented by a system based on special-purpose hardware that performs a specified function or action, or a combination of special-purpose hardware and computer instructions.

[0095] Furthermore, a computer program for carrying out the methods described herein and a non-transitory computer-readable storage medium storing the computer program are provided.The computer program can, for example, be downloaded (updated) to existing systems, or stored when these systems are manufactured.

[0096] Unless otherwise explicitly stated, elements and aspects discussed for or about a particular embodiment may be appropriately combined with elements and aspects of other embodiments. Embodiments of the present invention will be further described with reference to the accompanying drawings, which schematically illustrate embodiments according to the present invention. It will be understood that the present invention is not limited to these specific embodiments in any way. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] Various aspects of the invention will be explained in more detail with reference to exemplary embodiments shown in the accompanying drawings, in which:

[0098] FIG. 1 illustrates a system for illuminating one or more plants with artificial light according to one embodiment;

[0099] Figure 2 shows the spectrum of sunlight and artificial light at two different times according to one embodiment;

[0100] Figure 3 shows the spectrum of sunlight and artificial light at two different times according to one embodiment;

[0101] Figure 4 shows possible sunlight and artificial light spectra in an embodiment implementing a feedback loop;

[0102] Figure 5 A indicates the efficacy of each channel according to one embodiment;

[0103] Figure 5 B indicates the composition of white light and daylight;

[0104] Figure 6 indicating a total irradiance value of artificial light during a day according to one embodiment;

[0105] Figure 7 is a flow chart illustrating a method according to one embodiment;

[0106] Figure 8 shows sunlight reference data according to one embodiment;

[0107] Fig. 9 A control system according to one embodiment is shown. DETAILED DESCRIPTION

[0108] In the drawings, the same reference numbers refer to the same or similar elements.

[0109] FIG1 shows a system for illuminating one or more plants with artificial light 4 according to one embodiment. The lighting system includes a lighting device 2, which is configured to generate artificial light 4 having multiple artificial light components. Each artificial light component has a corresponding wavelength or wavelength range. In addition, the lighting device 2 can adjust the irradiance of the corresponding light component separately. Typically, the lighting device includes a plurality of separately controllable light sources, wherein at least some of the light sources emit different light colors. The system also includes a control system 100 (also referred to herein as a data processing system), which includes a processor configured to execute any one of the methods described herein. The control system 100 is preferably configured to send control signals to different light sources (e.g., LEDs) of the lighting device 2, and receive signals from sensors that may be present near the plants.

[0110] Figure 1A It is shown that one or more plants 6 can receive both artificial light 4 and sunlight 10. If the EM spectrum of the sunlight changes, for example because one sunlight component (e.g., red light) becomes relatively strong relative to other light components, it may be desirable to dim only the corresponding artificial light component (e.g., the red light component of the artificial light). This ensures that at any given time, one or more plants receive the appropriate EM spectrum of light. Note that the concept of an appropriate EM spectrum may depend on various factors. In any case, it should be appreciated that the desired EM spectrum may change over time.

[0111] This is for example caused by Figure 2 Shown. Figure 2 Two graphs of times, referred to as T1 and T2, are shown. For example, these times may be several hours apart. In this case, T1 may refer to a time during daytime, and T2 may refer to a time during dusk. The vertical axis of the graph represents irradiance, and the horizontal axis represents wavelength. Each graph may be understood as depicting a wavelength range from blue-green light on the left to red light on the right. In particular, the first wavelength range may be between 400-500nm, and the second wavelength range between 600-700nm.

[0112] Each diagram shows the so-called desired lighting spectrum for one or more plants, as indicated by the dotted lines. Figure 2 Indicating that the desired illumination spectrum may change over time. Note that the desired illumination spectrum defines a first predefined value for the indicated first wavelength range and a second predefined value for the indicated second wavelength range for T1, and a third predefined value for the indicated first wavelength range and a fourth predefined value for the indicated second wavelength range for T2. It should be appreciated that it is not required to define a complete desired EM spectrum for one or more plants. Predefined values ​​may be defined for a selected number of wavelengths or wavelength ranges.

[0113] In addition, each graph shows the EM spectrum of sunlight incident on one or more plants at the time in question. Note that at T1 during daytime, the sunlight spectrum includes a relatively strong blue / green sunlight component, while at T2 during dusk, the sunlight spectrum includes a relatively weak blue / green sunlight component. In particular, at T1, the first sunlight component of the first wavelength range has an EM spectrum of 0.0447 W / cm2. e5 The irradiance of the second sunlight component in the second wavelength range is E e6 At T2, the first sunlight component has an irradiance of E e7 (also referred to herein as the “seventh irradiance value”), and the second sunlight component has an irradiance of E e8 (also referred to herein as the "eighth irradiance value").

[0114] At T1, in order for one or more plants to receive the desired EM spectrum, artificial light is included in the E e1 a first artificial light component of a first wavelength range at an irradiance of 100 Å (also referred to herein as a “first irradiance value”), and ... e2 As a result, at T1, the one or more plants receive, in total, light of the first wavelength range having the first predefined irradiance value and light of the second wavelength range having the second predefined irradiance value. Similarly, at T2, the artificial light comprises light of the first wavelength range having the first predefined irradiance value and light of the second wavelength range having the second predefined irradiance value. e3 (also referred to herein as the "third irradiance value"), and light of the first wavelength range having an irradiance of E e4 The irradiance values ​​of the artificial light components may be determined based on the difference between the predefined irradiance value and the irradiance value already provided by sunlight for each light component.

[0115] Figure 2 The ratio E is shown e1 / E e2 Different from the ratio E e3 / E e4 , and the ratio E e1 / E e3 Different from the ratio E e2 / E e4 These different ratios indicate that different artificial light components are controlled separately.

[0116] Furthermore, assuming that the total irradiance of sunlight at T2 is lower than at T1, for example because T2 is at dusk and T1 is during daytime, then we see that the ratio E e1 / E e3 Less than ratio Ee2 / E e4 The irradiance of the first artificial light component increases more deeply than the irradiance of the second artificial light component.

[0117] You should understand that Figure 2 Only an example of a situation in which it is getting darker is shown. However, the method and system can of course also be used when the situation is getting brighter, such as when the sun is rising.

[0118] Figure 3 The chart contains Figure 2 However, these graphs more explicitly show the artificial light spectrum (see the dot-dash line).

[0119] As is clear from the above, the system preferably knows the EM spectrum of the sunlight incident on one or more plants at any given time. This allows the irradiance values ​​of the corresponding artificial light components to be accurately determined so that the one or more plants receive an appropriate EM spectrum in total.

[0120] For this reason, Figure 1B As depicted in , the system may include a sensor 8 for measuring the EM spectrum or at least two irradiance values ​​of two corresponding wavelengths or wavelength ranges of sunlight 10 incident on one or more plants. Note that the sensor 8 is preferably positioned so that it does not receive artificial light 4 generated by the lighting device 2. Based on the measured EM spectrum, and based on the expected EM spectrum, a suitable spectrum of the artificial light can be determined.

[0121] It should be appreciated that the sensor 8 is not necessarily configured to measure spectrally resolved irradiance values, i.e. at least two separate irradiance values ​​of at least two corresponding wavelengths or wavelength ranges. For example, the sensor 8 is configured to (only) measure non-spectrally resolved irradiance values, e.g. the total irradiance of sunlight incident on one or more plants. The sensor 8 may transmit a signal indicating the total irradiance value to the control system 100. The controller 100 may then determine an appropriate irradiance value for the artificial light component based on the total irradiance value.

[0122] The control system 100 may, for example, have stored corresponding total irradiance values ​​of sunlight associated with respective groups of irradiance values, each group of irradiance values ​​comprising an irradiance value of a first sunlight component of a first wavelength or wavelength range and an irradiance value of a second sunlight component of a second wavelength or wavelength range. For example, the control system 100 may have sunlight reference data indicating, for example, corresponding total irradiance values ​​of sunlight, corresponding EM spectra of sunlight. Based on this, the control system may determine the current EM spectrum of sunlight, and subsequently, based on the determined EM spectrum of sunlight, determine an appropriate spectrum of artificial light so that one or more plants receive the desired EM spectrum.

[0123] Figure 1C Yet another embodiment of the system is shown. Herein, the sensor 8 is positioned so that it receives 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 ​​of the respective light components. 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.

[0124] This setup achieves the same as referring to Figure 4 The feedback loop described herein can be described in detail. That is, the sensor 8 can continuously measure the EM spectrum incident on one or more plants, and can feed the EM spectrum back to the control system 100. The control system 100 can then monitor for each light component whether it is at a predefined level. If for one light component, the irradiance value is below the predefined value, the control system 100 can control the lighting system to increase the irradiance of the light component until the control system 100 again receives a signal from the sensor 8 indicating that the irradiance value of the light component is at the predefined level. If for one light component, the irradiance value is above the predefined value, the control system 100 can control the lighting system to reduce (dimming) the irradiance of the light component until the control system 100 again receives a signal from the sensor 8 indicating that the irradiance value of the light component is at the predefined level.

[0125] Figure 4 The situation at two times T1-δ and T2-δ is indicated. Here, this δ can be relatively small, such as a few seconds, however, this depends on how the system should respond.

[0126] In any case, at T1-δ, the sensor 8 has measured a total irradiance value for the first light component below a predefined value and a total irradiance value for the second light component above a predefined value. After the control system 100 has received a signal from the sensor 8 indicating this, the control system 100 may then adjust the irradiance value of the first light component in the artificial light by increasing the irradiance value of the first light component, and by decreasing the irradiance value of the second light component in the artificial light component, and monitor (again using a feedback loop) when the irradiance values ​​are at their respective predefined levels (e.g. Figure 2 ), to determine the appropriate irradiance value of the light component.

[0127] 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 similarly as described for the T1-δ case.

[0128] Figure 5A is a table showing individually controllable channels (channel 1, channel 2 and channel 3) for an embodiment of a lighting system. Such a system may be: based on a single lighting device with 3 different channels; or based on 3 different lighting devices, where each lighting device is considered as a separate channel; or a combination thereof. A lighting device may be a luminaire.

[0129] In this embodiment, channel 1 produces blue light, channel 2 produces white light, and channel 3 produces red light. White light is usually composed of B, G, R and a small portion of FR (far red light). Far red light can be understood as light with a wavelength between 700-800nm.

[0130] Typically, the energy efficiency (or more precisely, efficacy) of these channels will be different. Generally speaking, the red channel (channel 3) will require the least energy to produce 1 mole of photons, and therefore the red channel is usually the channel with the highest efficacy. The white channel usually has a lower efficacy.

[0131] For reference, Figure 5 B shows the composition of sunlight and white light. Here, PAR is the so-called photosynthetically active radiation and is the sum of all radiation in the B, G and R bands (in μmol / s / m 2 express).

[0132] The following general principles related to supplemental lighting can be implemented:

[0133] In the case of supplemental lighting for greenhouse horticulture, supplemental light is preferably provided during times when daylight levels are low. The process of photosynthesis shows a linear relationship with light level at low light levels. Increasing light levels will lead to saturation of photosynthesis at a certain point. When saturation occurs, light utilization efficiency (LUE) decreases, which is undesirable. Therefore, a good supplemental light level is related to daylight level: the lower the daylight level, the higher the supplemental light level can be, and vice versa.

[0134] For any crop there is an optimal light integral (the so-called daily light integral (DLI)), which is a compromise between biomass or fruit yield and LUE (for tomatoes, the desired DLI is usually 15 mol / m 2 / sky).

[0135] Most crops require dark periods. For tomatoes, this dark period should be at least 6 hours. If this rule is not followed, crop failure will occur.

[0136] Plants require a certain minimum proportion of blue light in the spectrum of light provided to ensure that their stomata open to absorb CO2 etc.

[0137] Red light has the highest LUE, followed by blue and white (or green).

[0138] With these principles in mind, your fill light profile for the day might look like this: Figure 6 (solid line). Assume that the grower desires that a dimming level of 80% is sufficient to achieve the desired DLI. In this example, the supplemental light is turned on at 05:00 with a dimming level of 80%. As the daylight level increases, the supplemental light level is gradually dimmed. At the end of the daylight period, it may have become clear that the dimming level of 80% is insufficient to achieve the desired DLI, so 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 dark period of sufficient duration.

[0139] Figure 7 A flow chart of the above steps is shown in FIG. 1 . A greenhouse control computer (e.g., controller 100a) may receive daylight measurements and / or user input. The daylight measurements may be spectrally resolved. The user input may indicate a desired EM spectrum for one or more plants, i.e., a total EM spectrum (a combination of sunlight and artificial light) that the one or more plants should receive. Based on the daylight measurements and the user input, the greenhouse control computer may output an overall dimming signal. Such an overall dimming signal may be considered a non-spectrally resolved dimming signal because it does not indicate at least two dimming levels for at least two corresponding channels.

[0140] The lighting control system can then determine a dimming signal for each channel based on the total dimming signal, thereby determining appropriate irradiance values ​​for at least two artificial light components. These dimming signals for different channels can then be sent to different drivers of the lighting source so that the plants receive appropriate lighting.

[0141] Figure 8 A portion of sunlight reference data according to one embodiment is shown. Each row contains a reference non-spectrally resolved irradiance value, in this example ranging from 50 / 100 to 90 / 100. In addition, each non-spectrally resolved irradiance value is associated with a reference EM spectrum of sunlight (see the rightmost column) (which thus indicates a reference irradiance value for a first sunlight component and a reference irradiance value for a second sunlight component).

[0142] For example, a reference non-spectrally resolved irradiance value and an associated reference sunlight EM spectrum may have been measured.

[0143] 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 (i.e., "July" and 10:00 AM). Of course, in practice, the sunlight reference data may contain more entries for all months, and more times of day for more reference irradiance values.

[0144] If a controller as described herein receives non-spectrally resolved irradiance values ​​for sunlight in July at around 10:00 a.m., the controller can determine which EM spectrum the sunlight has based on these sunlight reference data, 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. This in turn allows the determination of appropriate irradiance values ​​for the artificial light component.

[0145] Fig. 9 A block diagram illustrating a data processing system according to one embodiment is depicted.

[0146] like Fig. 9 As shown in , data processing system 100 may include at least one processor 102 coupled to memory element 104 via system bus 106. In this way, the data processing system may store program code in memory element 104. In addition, 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 appreciated that data processing system 100 may be implemented in the form of any system including a processor and a memory that is capable of performing the functions described in this specification.

[0147] The memory element 104 may include one or more physical memory devices, such as, for example, a local memory 108 and one or more mass storage devices 110. Local memory may refer to a random access memory or (multiple) other non-persistent memory devices generally used during the actual execution of the program code. The mass storage device may be implemented as a hard drive or other persistent data storage device. The processing system 100 may also include one or more cache memories (not shown) that provide temporary storage of at least some program code in order to reduce the number of times the program code must be retrieved from the mass storage device 110 during execution.

[0148] Optionally, input / output (I / O) devices, depicted as input device 112 and output device 114, may be coupled to the data processing system. Examples of input devices may include, but are not limited to, a keyboard, a pointing device such as a mouse, a touch-sensitive display, sensors described herein, a control system of greenhouse 100a, etc. Examples of output devices may include, but are not limited to, a monitor or display, speakers, a lighting system as described herein, etc. Input and / or output devices may be coupled to the data processing system directly or through intervening I / O controllers.

[0149] In an embodiment, the input and output devices may be implemented as a combined input / output device (in Fig. 9112 and output device 114). An example of such a combined device is a touch-sensitive display, sometimes also referred to as a "touch screen display" or simply a "touch screen." In such an embodiment, input to the device may be provided by movement of a physical object (such as, for example, a stylus or a user's finger) on or near the touch screen display.

[0150] Network adapter 116 may also be coupled to data processing system 100 to enable it to couple to other systems, computer systems, remote network devices, and / or remote storage devices through intervening private or public networks. Network adapters may include data receivers for receiving data transmitted to data processing system 100 by the systems, devices, and / or networks, and data transmitters for transmitting data from data processing system 100 to the systems, devices, and / or networks. Modems, cable modems, and Ethernet cards are examples of different types of network adapters that may be used with data processing system 100.

[0151] like Fig. 9 As depicted in FIG. 1 , memory element 104 may store application 118. In various embodiments, application 118 may be stored in local memory 108, one or more mass storage devices 110, or separate from local memory and mass storage devices. It should be appreciated that data processing system 100 may further execute an operating system (OS) that may facilitate the execution of application 118. Fig. 9 1 . Application 118 implemented in the form of executable program code may be executed by data processing system 100 (eg, by processor 102). In response to executing the application, data processing system 100 may be configured to perform one or more operations or method steps described herein.

[0152] In one aspect of the invention, data processing system 100 may be representative of a control system 100 as described herein.

[0153] In another aspect, data processing system 100 may represent a client data processing system. In this case, application 118 may represent a client application that, when executed, configures data processing system 100 to perform various functions described herein with reference to a "client." Examples of a client may include, but are not limited to, a personal computer, a portable computer, a mobile phone, and the like.

[0154] In yet another aspect, data processing system 100 may represent a server. For example, data processing system may represent a (HTTP) server, in which case application program 118, when executed, may configure the data processing system to perform (HTTP) server operations.

[0155] Various embodiments of the present invention may be implemented as a program product for use with a computer system, wherein the program(s) of the program product define the functionality of the embodiments (including the methods described herein). In one embodiment, the program(s) may be contained on various non-transitory computer-readable storage media, wherein as used herein, the expression "non-transitory computer-readable storage media" includes all computer-readable media, with the sole exception of temporary propagation signals. In another embodiment, the program(s) may be contained on various temporary computer-readable storage media. Illustrative computer-readable storage media include, but are not limited to: (i) non-writable storage media on which information is permanently stored (e.g., a read-only memory device within a computer, such as a CD-ROM disk readable by a CD-ROM drive, a ROM chip, or any type of solid-state non-volatile semiconductor memory); and (ii) writable storage media on which changeable information is stored (e.g., a flash memory, a floppy disk within a floppy disk drive or a hard disk drive, or any type of solid-state random access semiconductor memory). The computer program may run on the processor 102 described herein.

[0156] The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used herein, the singular forms "a", "an" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. It will be further understood that when used in this specification, the terms "include" and / or "comprise" specify the presence of stated features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0157] The corresponding structures, materials, actions, and equivalents of all means or step-plus-function elements in the following claims are intended to include any structure, material, or action for performing a function in combination with other claimed elements as specifically claimed. The description of the embodiments of the present invention has been presented for illustrative purposes, but is not intended to be exhaustive or limited to the embodiments in the disclosed form. Many modifications and variations will be clear to those of ordinary skill in the art without departing from the scope and spirit of the present invention. The embodiments are selected and described in order to best explain the principles of the present invention and some practical applications, and to enable other persons of ordinary skill in the art to understand the present invention for various embodiments with various modifications suitable for the particular use envisioned.

Claims

1. A computer-implemented method for controlling one or more luminaires configured to illuminate one or more plants with artificial light, the artificial light comprising a plurality of artificial light components, each artificial light component having a respective wavelength or wavelength range, the plurality of artificial light components comprising 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 a non-spectrally resolved irradiance value of sunlight incident on one or more plants, the method further comprising: determining an irradiance value of the first artificial light component and an irradiance value of the second artificial light component based on the non-spectrally resolved irradiance value, and controlling the one or more luminaires such that they provide artificial light to the one or more plants, the artificial light having an irradiance value determined for the first artificial light component and an irradiance value determined for the second artificial light component, such that the one or more plants receive light of the first wavelength or wavelength range at a predefined irradiance value for a first wavelength or wavelength range and light of the second wavelength or wavelength range at a predefined irradiance value for a second wavelength or wavelength range, The method further comprises: storing sunlight reference data indicating, for each of a plurality of reference non-spectrally resolved irradiance values, a reference irradiance value of a first sunlight component and a reference irradiance value of a second sunlight component, and An irradiance value of the first artificial light component is determined based on the sunlight reference data and an irradiance value of the second artificial light component is determined. 2 . The method of claim 1 , wherein receiving a signal indicative of a non-spectrally resolved irradiance value comprises measuring a non-spectrally resolved irradiance value of sunlight incident on the one or more plants.

3. The method according to any one of the preceding claims 1 or 2, wherein Determining the irradiance value of the first artificial light component comprises determining a difference between a reference irradiance value of the first sunlight component and a predefined irradiance value of the first wavelength or wavelength range; and / or Determining the irradiance value of the second artificial light component comprises determining a difference between a reference irradiance value of the second sunlight component and a predefined irradiance value of the second wavelength or wavelength range.

4. A method according to any one of the preceding claims, wherein The sunlight incident on the one or more plants has a first electromagnetic EM spectrum at a first time and has a second EM spectrum at a second time after the first time, the second EM spectrum being different from the first EM spectrum, wherein The received signal indicates a non-spectrally resolved irradiance value of sunlight incident on one or more plants at a first time, the method comprising: receiving a second signal indicative of a value of non-spectrally resolved irradiance of sunlight incident on the one or more plants at a second time, and determining a reference irradiance value of a first sunlight component incident on the one or more plants at a second time and a reference irradiance value of a second sunlight component incident on the one or more plants at a second time based on the second non-spectrally resolved irradiance value and the sunlight reference data, and - determining an irradiance value of the first artificial light component at the second time based on a predefined irradiance value of the first wavelength or wavelength range at the second time and based on a determined reference irradiance value of the first sunlight component incident on the one or more plants at the second time, and - determining an irradiance value of the second artificial light component at the second time based on a predefined irradiance value of the second wavelength or wavelength range at the second time and based on a determined reference irradiance value of the second sunlight component incident on the one or more plants at the second time, and Control the one or more luminaires so that they provide artificial light to the one or more plants, the artificial light having an irradiance value of a first artificial light component determined at a second time and having an irradiance value of a second artificial light component determined at the second time, so that the one or more plants receive light of the first wavelength or wavelength range at a predefined irradiance value for the first wavelength or wavelength range at the second time and light of the second wavelength or wavelength range at a predefined irradiance value for the second wavelength or wavelength range at the second time.

5. The method according to claim 4, wherein Determining the irradiance value of the first artificial light component at the second time comprises determining a difference between a reference irradiance value of the first sunlight component at the second time and a predefined irradiance value of the first wavelength or wavelength range at the second time; and / or Determining the irradiance value of the second artificial light component at the second time includes determining a difference between a reference irradiance value of the second sunlight component at the second time and a predefined irradiance value of the second wavelength or wavelength range at the second time.

6. The method according to claim 4 or 5, wherein a ratio between an irradiance value of the first artificial light component at a first time and an irradiance value of the second artificial light component at the first time is different from a ratio between an irradiance value of the first artificial light component at a second time and an irradiance value of the second artificial light component at the second time, and / or wherein A ratio between an irradiance value of the first artificial light component at the first time and an irradiance value of the first artificial light component at the second time is different from a ratio between an irradiance value of the second artificial light component at the first time and an irradiance value of the second artificial light component at the second time.

7. The method according to any one of claims 4 to 6, wherein the first wavelength range is between 400-500 nm, and the second wavelength range is between 600-700 nm; and wherein If the total irradiance of sunlight incident on the one or more plants at the second time is lower or higher, respectively, than the total irradiance of sunlight incident on the one or more plants at the first time, Then the ratio between the irradiance value of the first artificial light component at the first time and the irradiance value of the first artificial light component at the second time is respectively smaller or larger than the ratio between the irradiance value of the second artificial light component at the first time and the irradiance value of the second artificial light component at the second time.

8. A control system (100), comprising - an input interface (112) for receiving a signal indicative of a non-spectrally resolved irradiance value; - an output interface (114), configured to send the irradiance value of the first artificial light component and the irradiance value of the second artificial light component to a lighting device; and - A processor (102), wherein the processor is configured to perform the method according to any of the preceding claims 1-7.

9. A lighting system for illuminating one or more plants with artificial light, the lighting system comprising: - a lighting device configured to generate artificial light having a plurality of artificial light components, each artificial light component having a respective wavelength or wavelength range, and configured to individually adjust the irradiance of the respective light components, and - A control system according to claim 8.

10. A computer program comprising instructions for causing the lighting device according to claim 9 to execute the method according to any of the preceding claims 1-7.

11. A computer readable medium having stored thereon a computer program according to claim 10.

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