WO2023045404A1

WO2023045404A1 - Multi-stage periodic light-emitting apparatus for agricultural lighting and lighting method thereof

Info

Publication number: WO2023045404A1
Application number: PCT/CN2022/097607
Authority: WO
Inventors: Sen WANG; Qichang Yang; Zonggeng LI
Original assignee: Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences
Priority date: 2021-09-24
Filing date: 2022-06-08
Publication date: 2023-03-30
Also published as: CN115428658B; CN113840434B; CN113853977B; CN114128513B; CN113796226B; CN113847566A; CN113847566B; CN113812277A; CN113796226A; CN113940206A; CN116123512A; CN114128513A; CN114071827A; CN113840434A; CN113834014A; CN113753247B; CN113834014B; CN113812276A; CN114208558A; CN114128512A

Abstract

A multi-stage periodic light-emitting apparatus for agricultural lighting and a lighting method thereof, wherein the multi-stage periodic light-emitting apparatus comprises: a cultivation device (1) for carrying or accommodating agricultural products, and a lighting device (21) for providing lighting to the agricultural products cultivated in the cultivation device (1), wherein the lighting device (21) has a first lighting portion (21a) made as a linear light source that is configured to, when driven by a rotating component, perform dynamic scanning on the agricultural products cultivated in the cultivation device (1), wherein spaced growing areas are defined in the cultivation device (1) for the agricultural products, so that the first lighting portion (21a) provides lighting covering the growing areas having the agricultural products while performing the dynamic scanning.

Description

MULTI-STAGE PERIODIC LIGHT-EMITTING APPARATUS FOR AGRICULTURAL LIGHTING AND LIGHTING METHOD THEREOF

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to plant cultivation technology, and more particularly to a multi-stage periodic light-emitting apparatus for agricultural lighting and a lighting method thereof.

2. Description of Related Art

CN110418571A discloses a lighting device for plant cultivation that generates artificial light suitable for occasions of increased harvests, or a plant cultivation apparatus using the device, or a plant cultivation method using the device. The lighting device for plant cultivation projects artificial light to a plant from a lateral of the plant. The known device is characterized in comprising an LED circuit that has plural LED elements serving to generate the artificial light; an LED drive circuit that supplies the LED circuit with a LED drive current. The LED drive current includes a first period where the LED drive current is high and a second period where the LED drive current is low or zero. As the LED drive current changes periodically, the artificial light correspondingly has periodic variation in its intensity when irradiate the plant.

CN107439242A discloses a control method for shortening growth cycles of plants. The known method comprising: providing lighting to plants using a control device capable of shortening growth cycles of the plants, so that light density at plant surfaces is 2000-6000Lux. The method can be used to generate light having a waveband similar to that of sunlight, and can also be used to provide plants with light having a waveband matching their needs, thereby promoting plant growth.

In the prior art, plant cultivation shelves in plant factories are structurally unsatisfying in terms of resource usage and plant growth. Hence, the prior art has to be improved in at least one or more aspects.

SUMMARY OF THE INVENTION

To address at least one or more technical problems of the prior art, the present invention provides a multi-stage periodic light-emitting apparatus for agricultural lighting and a lighting method thereof.

To achieve the above-mentioned objectives, the present invention relates a multi-stage periodic light-emitting apparatus for agricultural lighting and a lighting method thereof, wherein the multi-stage periodic light-emitting apparatus comprises: a cultivation device for carrying or accommodating agricultural products, and a lighting device for providing lighting to the agricultural products cultivated in the cultivation device, wherein the lighting device has a first lighting portion made as a linear light source that is configured to, when driven by a rotating component, perform dynamic scanning on the agricultural products cultivated in the cultivation device, wherein spaced growing areas are defined in the cultivation device for the agricultural products, so that the first lighting portion provides lighting covering the growing areas having the agricultural products while performing the dynamic scanning. Preferably, agricultural products cultivated in a cultivation device may be plants.

According to a preferred mode, a lighting device deposited on a cultivation device comprises a first lighting portion located at the remote-ground end of the shaft of the cultivation device and a second lighting portion located on the outer lateral surface of the shaft. The first lighting portion and the second lighting portion each include plural light-emitting modules that can be driven independently. The light-emitting module is constructed from a combination of light-emitting units that can be independently driven and have different emission wavelengths and/or light colors. The light-emitting units of any light-emitting module in the first lighting portion are separated from each other by an installation clearance that gradually decreases as the distance between the light-emitting module and the shaft of the cultivation device increases. Preferably, the light-emitting units of any light-emitting module in the second lighting portion are separated from each other by an installation clearance that gradually decreases as the distance between the light-emitting module and the remote-ground end of the shaft of the cultivation device increases. Preferably, the first lighting portion is at least able to adjust an irradiating posture by which it irradiates plants in the cultivation device and/or light quality of the corresponding light source through an external drive, and the external drive associates monitoring data of a growing state and/or a growing environment of the plants through an external detecting device with preset thresholds. Preferably, the first lighting portion is at least able to swing against a shaft and rotate about the shaft by means of an external drive, and/or to adjust light source proportions of each light-emitting unit through an external drive.

Preferably, the lighting device serves to provide controllable light that has changeable lighting intensity/illumination to the agricultural products in the cultivation device in response to input of an adjustable pulse voltage, wherein the pulse voltage has a pulse period that can be at least divided into a first waveband and a second waveband. Preferably, the lighting device provides the controllable light by adjusting lighting duration, the lighting intensity and/or proportions of the light sources of the corresponding light-emitting unit according to voltage variation and/or current variation of the first waveband. Preferably, the lighting device generates the controllable light having the lighting intensity/illumination close to or equal to zero candela according to a no-voltage state of the second waveband.

Preferably, the cultivation device comprises first rails and second rails arranged coaxially. Preferably, at least one of the first rails extends from a remote-ground end to a near-ground end of the shaft and spirals about the shaft of the cultivation device, the first rail having a curve radius or its distance to the shaft increasing gradually in the extending direction from the remote-ground end to the near-ground end of the shaft. Preferably, plural second rails are such distributed on a peripheral surface of the shaft that adjacent second rails are staggered from each other according to set gaps provided in a first direction and/or a second direction, and when viewed in the first direction, the plural second rails arranged in the extending direction from the remote-ground end to the near-ground end of the shaft having lengths that are increasing gradually. Preferably, the first rails having a first channel and the second rails having a second channel intersect each other so as to form plural cultivation portions for cultivating the plants such that adjacent cultivation portions are staggered from each other.

Preferably, plural first rails that extend axially along the shaft and spiral about the shaft are arranged on a peripheral surface of the shaft according to identical and/or different gaps configured in a first direction and/or a second direction, so that based on the gaps, plural first rails form cultivation layers separated by layer distances that are not completely equal. Preferably, plural second rails each form a certain included angle with the ground, and a curvature at any point on the second rail gradually decreases as its distance from the shaft increases, so that a nutrient solution can flow down by gravity so as to nourish the plants in the cultivation portion, and the flow rate of the nutrient solution flowing in the extending direction of the second rail gradually increases as the curvature of the second rail gradually decreases. Preferably, a hollow channel extends axially at the inner side of the shaft, wherein a pipe for delivering the nutrient solution is received in the hollow channel. Preferably, the pipe has plural outlets such formed on its outer lateral surface that adjacent said outlets are separated from each other in the axial direction of the shaft. Two ends of the pipe are connected to two ends of the first rail extending into the shaft, respectively, wherein each said outlet is communicated with one end of the second rail extending into the shaft.

Preferably, the multi-stage periodic light-emitting apparatus is applicable to a management system that at least comprises: a managing device at least for real-time receiving state detection data of a plant factory, generating corresponding modulation data through calculation and analysis, and distributing the modulation data to corresponding devices; an imaging device for real-time monitoring growing states of plants in the plant factory and generating relevant images, and sending image information about the growing states of the plants to a managing device that generates the modulation data accordingly; a first detecting device for detecting plural parameters about a cultivation environment in the plant factory and transmitting information of the plural parameters to the managing device that generates the modulation data accordingly, so that the managing device can adjust the cultivation environment in the plant factory according to the modulation data; and an operation device, storing therein the modulation information to adjust the cultivation environment in the plant factory, for calling and distributing the corresponding modulation information in response to instructions from the managing device. Preferably, the management system further comprises: a transceiver device serving to receive detection information uploaded by the imaging device and/or the first detecting device and send them to the managing device, and to receive the modulation information that is distributed to the operation device by the managing device and send it to the first detecting device and all the other devices except for itself; and an adjusting module serving to receive the modulation information distributed by the transceiver device, and according to the modulation information, to adjust the irradiating postures and/or the light qualities of the corresponding light sources for the first lighting portion and/or the second lighting portion to provide the supplementary lighting.

Preferably, the present invention provides a lighting method based on a management system, comprising a management system which can adjust the cultivation environment in the plant factory in a real-time manner, wherein the process for the management system to adjust the plant cultivation environment in a real-time manner at least comprises the following steps: real-time receiving state detection data of a plant factory by a managing device and generating corresponding modulation data through calculation and analysis; real-time monitoring growing states of plants in the plant factory through an imaging device, generating relevant images, and sending image information about the growing states of the plants to a managing device that generates the modulation data accordingly; detecting plural parameters about a cultivation environment in the plant factory by a first detecting device and transmitting information of the plural parameters to the managing device that generates the modulation data accordingly, so that the managing device can adjust the cultivation environment in the plant factory according to the modulation data; in response to instructions from the managing device, calling and distributing through an operation device the corresponding modulation information stored therein to adjust the cultivation environment in the plant factory; receiving through a transceiver device the detection information uploaded by the imaging device and/or the first detecting device and send them to the managing device, and receiving the modulation information that is distributed to the operation device by the managing device and sending it to the first detecting device and all the other devices except for itself; and according to the modulation information distributed by the transceiver device, adjusting by an adjusting module the irradiating postures and/or the light qualities of the corresponding light sources for the first lighting portion and/or the second lighting portion to provide the supplementary lighting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates the structure of a first rail according to a preferred mode of the present invention;

FIG. 2 schematically illustrates the structure of a second rail according to a preferred mode of the present invention;

FIG. 3 schematically illustrates the distribution of plural first rails along a shaft according to a preferred mode of the present invention;

FIG. 4 is a top view of the first rail according to a preferred mode of the present invention;

FIG. 5 is a top view of the second rail according to a preferred mode of the present invention;

FIG. 6 is a top view of combined first and second rails according to a preferred mode of the present invention, showing that cultivation portions are formed by the combined first and second rails;

FIG. 7 schematically illustrates the structure of the shaft according to a preferred mode of the present invention;

FIG. 8 schematically illustrates the structure of a first lighting device according to a preferred mode of the present invention;

FIG. 9 schematically illustrates the first lighting device in one of its irradiating states according to a preferred mode of the present invention; and

FIG. 10 diagrammatically illustrates the control principle according to a preferred mode of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be described in detail with reference to the accompanying drawings.

To be defined at first, in the present invention, the “first direction” refers to the direction parallel to the ground or the X axis, and the “second direction” refers to the direction perpendicular to the ground or parallel to the Y axis.

The present invention provides a multi-stage periodic light-emitting apparatus for agricultural lighting and a lighting method thereof, which are applicable to plant factories. Accordingly, the present invention further provides a plant factory, which at least comprises plural cultivation devices 1 that are installed in the plant factory for carrying plants to be cultivated, and a management system 2 that at least serves to adjust the cultivation environment in the plant factory in a real-time manner according to growing states and growing environments of the plants.

According to a preferred mode, the cultivation device 1 in the plant factory at least comprises a plant cultivation shelf 10. The plant cultivation shelf 10 may comprises a shaft 101, at least one first rail 102 extending spirally over the peripheral surface of the shaft 101, and plural second rails 103 distributed over the peripheral surface of the shaft 101 and spaced from each other in the axial direction of the shaft 101. Preferably, the end of the shaft 101 close to the ground is defined as a near-ground end 101a, and the end distant from the ground is defined as a remote-ground end 101b.

According to a preferred mode, the first rail 102 spirally extending over the peripheral surface of the shaft 101 is zigzagged from the remote-ground end 101b to the near-ground end 101a, as shown in FIG. 1. Preferably, the first rail 102 spirally extending over the peripheral surface of the shaft 101 is configured to spirally extend along the axis of the shaft 101 and formed as a spiral rail expanding outward from the axis of the shaft 101 while extending downward. Preferably, the spiral expansion may be a regular spiral and/or an irregular spiral, as long as it forms the posture that the vertical distance between any point in the curve extending along the set direction and the shaft 101 gradually increases or decreases.

According to a preferred mode, the first rail 102 spirally extending along the shaft 101 forms plural cultivation layers separated by layer distances that are not completely equal. Every cultivation layer has an area defined by the first rail 102 circling the shaft 101, and the area of at least one of the cultivation layers may be defined as a complete plane, a half plane, or other options depending on the cultivation needs of the cultivation layers. Since plants cultivated in the cultivation layers may be the same or different, and the plants may be in different growth stages and thus have different morphological forms, the plants under cultivation can be diverse at least in terms of appearance. Therefore, preferably, the layer distances between the cultivation layers are adaptive to the types of plants actually cultivated as well as growth properties and growth performance of the plants, so as to promote plant growth and development, thereby achieve their ideal growing states. Preferably, with a structure designed properly, the first rail 102 is able to not only ensure ideal growth of the plants cultivated in the cultivation layers, but also make full use of the limited space of the cultivation layers.

According to a preferred mode, the first rail 102 is configured to take the shaft 101 as its center of rotation, and extends spirally from the remote-ground end 101b of the shaft 101 toward the near-ground end 101a of the shaft 101. In addition, the curve radius, at which the first rail 102 extends form the remote-ground end 101b to the near-ground end 101a of the shaft 101, or the vertical distance between the first rail and the shaft 101 is of the posture that it increases geometrically and/or proportionately. Optionally, at least a part of the first rail 102 that is close to the remote-ground end 101b is smaller in terms of curve radius or in terms of vertical distance to the shaft 101. On the contrary, at least a part of the first rail 102 that is close to the near-ground end 101a is greater in terms of curve radius or in terms of vertical distance to the shaft 101. This configuration is made with the consideration that plants at the remote-ground end 101b are closer to light sources and thus receive more plentiful and more intense light than plants at the lower side. Plants at the near-ground end 101a are relatively distant from light sources, and thus receive less plentiful and less intense light than plants at the upper side. Preferably, at least a part of the rail that is relatively close to the remote-ground end 101b may be used to plant light-demanding plants or long-day plants, or the same part of the rail that is relatively small in curve radius may be used to plant small plants. On the contrary, at least a part of the rail that is relatively close to the near-ground end 101a may be used to plant plants having weak light tolerance or short-day plants, or the same part of the rail that is relatively large in curve radius may be used to plant large plants. Further, a first channel 1020 matching the first rail 102 in shape may be arranged to extend along the first rail 102 at the inner side of the first rail. The first channel 1020 is configured to carry and accommodate plants and deliver a nutrient solution.

According to a preferred mode, as shown in FIG. 3, plural first rails 102 may be arranged at the peripheral surface of the shaft 101. Specifically, the plural first rails 102 may be separated in a first direction and/or a second direction by certain clearances while spirally extending at the peripheral surface of the shaft 101. Optionally, the clearances between the plural first rails 102 in the first direction and/or the second direction may be identical or different, depending on the types of plants to be cultivated in the plant cultivation shelf 10. For adapting to growth morphology or light-exposure needs of different plants, the clearances between the plural first rails 102 may be adjusted so that plants at every site in every cultivation layer of the plural first rails 102 can receive proper lighting and achieve ideal growth matching their respective growth properties.

According to a preferred mode, as shown in FIG. 6, on the peripheral surface of the shaft 101, two first rails 102 having spirally expanding structures are separated by a clearance. Preferably, taking the shaft 101 as the center, in a direction that is parallel to the first direction and leaves the shaft 101, each of the first rails 102 is such arranged that its overall volume increases geometrically and/or proportionately. Or to say, the curve radius of at least a part of each of the first rail 102 that is in the same plane increases geometrically and/or proportionately. Additionally, the first rail 102 relatively close to the shaft 101 has an overall volume smaller than that of the first rail 102 relatively distant from the shaft 101. On other words, when viewed in the second direction from the top, the plural cultivation layers constructed by the plural first rails 102 are staggered from each other. Preferably, due to phototropism, the plants in different cultivation layers of the first rails 102 mutually staggered can all be expose to lighting to the largest possible extent and thereby receive light that is at a proper ratio and of proper intensity, so as to keep the good growing state (e.g., developing upright) to the largest possible extent.

According to a preferred mode, a ring-like second lighting portion 21b is provided on at least a part of the peripheral surface of the shaft 101, and at least one first lighting portion 21a of a roughly linear shape is movably provided at the remote-ground end 101b of the shaft 101. Specifically, the first lighting portion 21a may be of a folding structure. When the plants do not need supplementary lighting and simply the natural light or sunlight, the first lighting portion 21a covers the first rails 102 from above can shade at least a part of the plants below it, and prevents the natural light or sunlight light from reaching the shaded surfaces on the plants. As a result, for a long term, plants with these shaded surfaces can grow slowly as compared to nearby plants. This problem can be effectively solved by the folding structure as disclose herein. The first lighting portion 21a may be folded toward the shaft 101 manually or by means of an external drive, so as not to block light, thereby allowing the plants on the first rails 102 to receive light uniformly and develop normally. Alternatively, at least one first lighting portion 21a may be drawn toward the shaft 101 manually or in virtue of an external autonomous driving means to the extent that the first lighting portion 21a becomes parallel to the shaft 101, so as not to partially shade the underlying plants by the first lighting portion 21a and compromise their development.

According to a preferred mode, the second lighting portion 21b may provide supplementary lighting to the plants on the spiral first rails 102 as it radially emits in a roughly ring-like pattern against the shaft 101. Specifically, when the first lighting portion 21a irradiate the plants on the underlying first rails 102 from above, with the ideal case excepted from this discussion, some plants may shade each other from the lighting. For example, plants relatively close to the top may shade plants below them from light. Besides, in the process where the first lighting portion 21a provides lighting to the plants on the first rails 102 in swinging and/or rotating motions, light pockets can appear on the plants. For example, at least a part of the first rails 102 relatively close to the shaft 101 may be shaded by the part of first rails 102 located more peripherally. Consequently, at least a part of the plants may be prevented from receiving effective lighting at their leaves for photosynthesis that is necessary to plant growth and development. As a solution to this problem, the second lighting portion 21b is designed to work with the first lighting portion 21a and provide the plants on the first rails 102 with supplementary lighting from inside to outside. Particularly, when the first lighting portion 21a fails to provide perfect, full lighting coverage, the second lighting portion 21b may be used to irradiate the plants from different angles. Preferably, in view of phototropism, the second lighting portion 21b and the first lighting portion 21a may provide lighting at the same or different intensities. This is to ensure the optimal growth of the plants on each cultivation layers, so as to obtain good plant quality and make full use of available space on each first rail 102 and its cultivation layers. Further, a ratio of lighting intensity between the second lighting portion 21b and the first lighting portion 21a may be adjusted according to the real-time growing states of the plants in each cultivation layer. Specifically, an image-capturing device or the like may be used to detect the real-time growing states of the plants.

According to a preferred mode, the first lighting portions 21a may be roughly parallel to the ground when projecting light to the plants on the first rails 102. Alternatively, the first rails 102 may be parallel to the elements of the respective circular cones they form when projecting light to the plants on the first rails 102, as shown in FIG. 9. Preferably, the first lighting portions 21a may be mounted on a rotating component installed at the remote-ground end 101b of the shaft 101 and provide the plants on the first rails 102 with a light coverage in the shape of a circular truncated cone and/or a circular cone as they rotate about the shaft 101. The rotating component may be any structure known in the art as long as it makes the first lighting portions 21a rotate about the shaft 101, without limitation. Preferably, compared to a static light source with large coverages that is conventionally employed for this purpose, the first lighting portion 21a as proposed in the embodiments of the present invention is configured to provide dynamic, moving, linear lighting, so the light pattern of the first lighting portion 21a is more constrictive, leading to increased lighting intensity. In addition, the dynamic light helps reduce light pocket and allow more leaves to receive the light and prevents cilia on leaves from blocking the light, so that photoreceptors at the back of a leaf other can also get sufficient light and the plant can develop better.

According to a preferred mode, the first lighting portions 21a are posed manually or in virtue of an external autonomous driving means before irradiating the underlying plants. As to the external autonomous driving means, such posing is made according to the growing states or the growing environment of the plants as monitored by an external device. For example, to monitor the growing states of the plants, a known image-capturing device conventionally used for measuring plant leaf sizes or plant growth heights may be used. Further, to monitor the growing environment of the plants, sensors may be employed to detect parameters like the air humidity, temperature, lighting intensity, CO ₂ concentration or O ₂ concentration in the cultivation area of the plants.

Preferably, after the image-capturing device acquires images showing the growing states of the plants in the cultivation layers at the upper ends of the first rails 102, an external control device or a central control device is used to analyze the images and compare them with standard data stored in a database. For example, when the leaf size reaches a preset growth threshold, an external control device or a central control device can drive the first lighting portions 21a to expand against the shaft 101. At this time, the plants in the lower cultivation layers may have not reached the growth threshold. Because of the relatively large distances between the terminal of each first lighting portions 21a and the lower cultivation layers, the resulting lighting intensity can be reduced. To compensate the reduction, an external drive may be used so as to increase the lighting intensity of the light-emitting elements of the first lighting portion 21a at the side distant from the shaft 101, and properly adjust the lighting intensity of the light-emitting elements in other sections of the first lighting portion 21a, thereby offsetting the effect of the light distance on lighting intensity.

Alternatively, after the image-capturing device acquires images showing the growing states of the plants in at least a part of the cultivation layers of the first rail 102, an external control device or a central control device is used to analyze the images and compare them with standard data stored in a database. For example, when the leaf size reaches a preset growth threshold, an external control device or a central control device can drive the first lighting portions 21a to come close to and/or go distant from the shaft 101 in a retracting or expanding motion, and the rotating components can drive the first lighting portions 21a to rotate. For the plants in other zones not satisfying the growth threshold, an external drive may be used to adjust the lighting intensity of the light-emitting elements in the different sections of the first lighting portions 21a, thereby satisfying the light-exposure needs of these plants.

Preferably, after the sensor detects that the CO ₂ concentration, the O ₂ concentration, or the ratio therebetween in at least a part of the area of the first rails 102, an external control device or a central control device is used to analyze the data and compare them with standard data to see whether the CO ₂ concentration, the O ₂ concentration, or the ratio therebetween reaches a preset threshold. For example, if the CO ₂ concentration is lower than a certain threshold and the O ₂ concentration is higher than a certain threshold or their ratio is higher than a certain threshold, it is determined that the plants in the area have relatively strong net photosynthesis. Accordingly, an external control device or a central control device may be used to retract and/or expand the first lighting portions 21a, and the rotating component can drive the first lighting portions 21a to rotate, thereby decreasing lighting in the area where the plants satisfy the preset threshold and/or increasing lighting in the area where the plants have not reached the preset threshold.

According to a preferred mode, the first lighting portion 21a and the second lighting portion 21b may each be composed of plural light-emitting modules 210 that can be driven independently. Specifically, each light-emitting module 210 may be composed of plural light-emitting units that can be driven independently and have different emission wavelengths or light colors. Specifically, each light-emitting module 210 is provided with a first light-emitting unit 210a, a second light-emitting unit 210b, and a third light-emitting unit 210c.

Optionally, the first light-emitting unit 210a may use a red LED light source having an emission wavelength of 620nm～760nm. The second light-emitting unit 210b may use a blue LED light source having an emission wavelength of 400nm～450nm. The third light-emitting unit 210c may use a green LED light source having an emission wavelength of 492nm～577nm.

Preferably, by independently driving the first light-emitting unit 210a, the second light-emitting unit 210b, and the third light-emitting unit 210c that have different emission wavelengths, light satisfying different growth needs of the plants on the first rails 102 can be provided.

Preferably, the first light-emitting unit 210a, the second light-emitting unit 210b, and the third light-emitting unit 210c can be driven simultaneously so as to compose composite light that simulate natural light. Furthermore, by adjusting the intensity shares of the light-emitting units, the light quality of the composite light can be changed. This in turn changes the lighting effect on the plants and thereby promotes the plants to reach their optimal growing states in the ideal lighting environment. Specifically, in view that a high share of blue light may not only retard or inhibit plant growth and prevent synthesis of carbohydrates, but also cause harm to human eyes, a desired scheme is about properly increasing the share of red light and decreasing the share of blue light.

According to a preferred mode, plural first rails 102 take the shaft 101 as its center of rotation and extend from the remote-ground end 101b to the near-ground end 101a of the shaft 101 while spiraling about the shaft 101. The curve radius at which each first rail 102 spirally extends from the remote-ground end 101b to the near-ground end 101a of the shaft 101 or the vertical distance to the shaft 101 increases geometrically and/or proportionately. For meeting the lighting needs specific to the foregoing configuration of the first rails 102, in each first lighting portion 21a, the light-emitting module 210 composed of plural light-emitting units that can be driven independently and have different emission wavelengths or light colors is such configured that when viewed in the arranged direction of the roughly linear first lighting portion 21a, the installation clearance among the first light-emitting unit 210a, the second light-emitting unit 210b, and third light-emitting unit 210c in each light-emitting module 210 increases or decreases proportionately, as shown in FIG. 8. Stated differently, the installation clearance among the first light-emitting unit 210a, the second light-emitting unit 210b, and third light-emitting unit 210c in the light-emitting module 210 relatively close to shaft 101 is greater than the installation clearance among the first light-emitting unit 210a, the second light-emitting unit 210b, and third light-emitting unit 210c in the light-emitting module 210 relatively distant from the shaft 101. Preferably, the exact installation clearances may be determined according to the actual configuration of the first rails 102 and with reference to parameters like the photosynthetic photon flux and the photon flux as computed using suitable equations.

According to a preferred mode, the installation clearance among the light-emitting elements in the light-emitting modules 210 are set different according to the effect of the light quality, compositional proportions, and intensity of the first lighting portion 21a on the plants carried by the underlying first rails 102. Specifically, when light-emitting elements of different emission wavelengths arranged alternately emit light simultaneously, at least some parts of their respective light range can overlap each other. Similarly, at least some parts of light-emitting modules 210 composed of these light-emitting elements can overlap each other. As a result, light in the overlapped area is higher than light in the other areas in terms of photosynthetic photon flux. The resulting inhomogeneous light is nevertheless disadvantageous to plant growth, and this problem can become more significant in a multi-layer spiral structure like what is formed by the first rail 102 of the present invention.

According to a preferred mode, when the horizontally posed first lighting portions 21a irradiate the plants in the underlying cultivation layers of the first rails 102, if the installation clearances and the lighting intensity are both constant throughout the apparatus, the levels of effective lighting reaching the plants in different cultivation layers are different because the plants in different cultivation layers are distant from the first lighting portions 21a in the second direction differently. Particularly, the light available to the plants in the lower cultivation layers of the first rails 102 is even more limited. Further, since in the present invention the curve radius, at which each first rail 102 spirally extends from the remote-ground end 101b to the near-ground end 101a of the shaft 101, or the vertical distance to the shaft 101 increases geometrically and/or proportionately, for ensuring even light exposure of the plants in different cultivation layers of the first rails 102 each having a changing curve radius, the installation clearance among the light-emitting elements in the first lighting portion 21a decreases gradually as the curve radius increases geometrically and/or proportionately when the first rail 102 extends from the remote-ground end 101b to the near-ground end 101a of the shaft 101. In other words, at least a part of the plants relatively close to the remote-ground end 101b of the first rail 102 is relatively close to the first lighting portion 21a and thus receives effective lighting in the relatively high level, so the installation clearance among the light-emitting elements at this area is relatively large, thereby preventing excessively high photosynthetic photon flux generated at the overlapped area among the light ranges. This not only prevents excessive light exposure of plants at the corresponding sites and waste of the redundant light, but also eliminates the growth-inhibiting effects brought about by excessive light exposure. Furthermore, radiation diffusion of light can be accomplished to reduce superposition of light generated by the light-emitting elements, and to in turn expand the overall coverage of the disclosed apparatus.

According to a preferred mode, the installation clearance among the light-emitting elements in the light-emitting module 210 at the side of the first lighting portion 21a close to the shaft 101 is relatively large, so the superposed light intensity acting on at least a part of the plants near the remote-ground end 101b of the first rail 102 can be reduced, thereby allowing light generated by these light-emitting elements to better reach plants in other cultivation layers. On the other hand, the installation clearance among the light-emitting elements in the light-emitting module 210 at the tail of the side of the first lighting portion 21a distant from the shaft 101 is the smallest. Similarly, at least a part of the plants relatively close to the near-ground end 101a of the first rail 102 is distant from the first lighting portion 21a, and thus only receive the effective light in the relatively low level, so the installation clearance among the light-emitting elements at this area is relatively small, thereby increasing the photosynthetic photon flux generated at the overlapped area among the light ranges. This not only prevents excessive low exposure of plants at the corresponding sites under the composite light and enhances the utilization rate of light, but also eliminates the growth-inhibiting effects brought about by insufficient light exposure. Meanwhile, radiation diffusion of light can be accomplished to increase superposition of light generated by the light-emitting elements, and to in turn decrease light dispersion, making more light concentrate here, thereby creating relatively strong light exposure.

According to a preferred mode, the installation clearance among the light-emitting elements in the light-emitting module 210 at the side of the first lighting portion 21a close to the shaft 101 is relatively large, so the superposed light intensity acting on at least a part of the plants near the remote-ground end 101b of the first rail 102 can be reduced, thereby allowing light generated by these light-emitting elements to better reach plants in other cultivation layers. Preferably, according to the arrangement of the installation clearances among light-emitting elements in the first lighting portions 21a. When the first lighting portions 21a are properly posed to irradiate the plants on the first rails 102, the variation in lighting intensity caused by the variation in light distance can be compensated by adjusting the proportions and lighting intensities of the light-emitting elements in different sections of the first lighting portion 21a the according to the distance between the plants in each cultivation layer of first lighting portion 21a.

According to a preferred mode, the installation clearance among the light-emitting units in each light-emitting module 210 of the second lighting portion 21b is set in the same way as described above for the first lighting portion 21a. Specifically, in the extending direction from the remote-ground end 101b to the near-ground end 101a of the shaft 101, the installation clearances among the light-emitting units in the light-emitting modules 210 of the second lighting portion 21b decrease successively. As such, the installation clearance among the light-emitting elements in each light-emitting module 210 on the axial direction of the shaft 101 and at the side of the second lighting portion 21b that is close to the remote-ground end 101b is relatively large, and the installation clearance among the light-emitting elements in each light-emitting module 210 on the axial direction of the shaft 101 and at the side of the second lighting portion 21b that is close to the near-ground end 101a is relatively small.

Preferably, the part of the first rail 102 at its side close to the remote-ground end 101b of the shaft 101 has a relatively small curve radius or is relatively close to the shaft 101, and therefore this part of rail can receive more plentiful and more intense effective lighting than the lower part of the rail. Thus, for reducing superposed light irradiating this part of rail, lowering the overall lighting intensity, and enhancing the comprehensive utilization rate of light, the light-emitting elements in the light-emitting module 210 at this part of rail have a relatively large installation clearance. This also allows light generated by the light-emitting module 210 here to better irradiate plants in other cultivation layers, thereby decreasing the share of redundant light irradiating at least a part of the plants at the remote-ground end 101b and increasing the share of effective light irradiating at least a part of the plants in other cultivation layers.

Preferably, the installation clearance among the light-emitting elements in the light-emitting module 210 on the axial direction of the shaft 101 and at the side of the second lighting portion 21b close to the near-ground end 101a is relatively small. Similarly, at least a part of the plants relatively close to the near-ground end 101a of the first rail 102 is distant from the second lighting portion 21b, and thus only receive the effective light in the relatively low level, so the installation clearance among the light-emitting elements at this area is relatively small, thereby increasing the photosynthetic photon flux generated at the overlapped area among the light ranges. This not only prevents excessive low exposure of plants at the corresponding sites under the composite light and enhances the utilization rate of light, but also eliminates the growth-inhibiting effects brought about by insufficient light exposure. Meanwhile, radiation diffusion of light can be accomplished to increase superposition of light generated by the light-emitting elements, and to in turn decrease light dispersion, making more light concentrate here, thereby creating relatively strong light exposure. Preferably, the exact installation clearances may be determined according to the actual configuration of the first rails 102 and with reference to parameters like the photosynthetic photon flux and the photon flux as computed using suitable equations.

According to a preferred mode, as shown in FIG. 2 and FIG. 5, plural second rails 103 of different lengths are separated along the axial direction of the shaft 101 and distributed over the peripheral surface of the shaft. Specifically, every second rails 103 is inclined with respect to the ground so as to form a certain included angle with the ground. Preferably, such inclination is helpful for liquid to naturally flow down by gravity. Further, a second channel 1030 is formed at the inner side of the second rail 103. The first channel 1020 serves to accommodate the first rail 102 and deliver a nutrient solution. The first rail 102 and the second rail 103 are arranged coaxially. In addition, plural first rails 102 and plural second rails 103 with their respective channels intersecting jointly create plural cultivation portions P for cultivating plants in the cultivation layers of the first rails 102, as shown in FIG. 6. Particularly, when viewed from top in the second direction, the cultivation portions P in the adjacent cultivation layers are staggered with a clearance left therebetween. This helps maximize the utilization rate of cultivation space in both the first and second directions.

According to a preferred mode, when viewed from top in the second direction, the lengths of the plural second rails 103 arranged in the direction from the remote-ground end 101b to the near-ground end 101b of the shaft 101 successively increase, as shown in FIG. 2 and FIG. 5. Specifically, the second rail 103 closest to the remote-ground end 101b of the shaft 101 has the smallest length, and the second rail 103 closest to the near-ground end 101b of the shaft 101 has the greatest length. Further, the difference in length between the second rail 103 adjacent in the axial direction of the shaft 101 may be selected according to the configuration of the first rail 102. Since in the present invention the curve radius at which each first rail 102 spirally extends from the remote-ground end 101b to the near-ground end 101a of the shaft 101 or the vertical distance to the shaft 101 increases geometrically and/or proportionately, the second rail 103 closer to the remote-ground end 101b requires a smaller curve radius of the first rails or fewer first rails 102, while the second rail 103 closer to the near-ground end 101a requires a greater curve radius of the first rails or a fewer number of first rails 102.

According to a preferred mode, plural first rails 102 and plural second rails 103 with their respective channels intersecting jointly create plural cultivation portions P for cultivating plants in the cultivation layers of the first rails 102. Preferably, plural cultivation portions P in the cultivation layers of the first rail 102 may have identical or different clearances, depending on the types of plants to be cultivated in the cultivation layers and full use of the limited space. The number of the cultivation portions P and their clearances can be changed by adjusting the number of the second rails 103 and their clearances, in addition to the adjustment on the number of the first rails 102, their clearances, and the layer distances between the cultivation layers, so as to make full use of the cultivation space in the cultivation layers of the first rail 102, and improve light exposure of the plants in the cultivation layers.

According to a preferred mode, the present invention is applicable to the existing practices of hydroponics and/or aeroponics. Taking hydroponics for example, for cultivation performed in plural cultivation portions P formed by the first rails 102 and the second rails 103, a nutrient solution in the first channel 1020 of the first rail 102 can easily flow down due to the gravity, and reach the cultivation portions P to soak the plants, so that the plants in the cultivation portions P can absorb nutrition delivered by the nutrient solution and have their growth promoted.

According to a preferred mode, as shown in FIGs. 1-6, the shaft 101 is perpendicular to plural imaginary round, oval, or spiral planes of the first rails 102 that are spaced in the axial direction of the shaft 101 and defined by the first rails 102 surrounding the shaft. Preferably, the shaft 101 defines therein a hollow channel 1010 extending axially. Further, the hollow channel 1010 contains therein a pipe 1011 for delivering the nutrient solution. Plural outlets 1012 are formed on the peripheral surface of the pipe 1011 and are separately staggered along its axial direction, as shown in FIG. 7.

According to a preferred mode, every outlet 1012 is communicated with the end of the second rail 103 extending into the shaft 101. Preferably, a liquid pumping device such as a centrifugal pump may be provided inside the pipe 1011, so as to drawn the nutrient solution at the bottom of the pipe 1011 upward to the top of the pipe 1011 along the pipe 1011. When being lifted and arriving at each outlet 1012, the nutrient solution can flow into the second channel 1030 of the second rail 103 through the outlet 1012, and then flow down by gravity in virtue of the inclination of the second rail 103. Further, the two ends of the pipe 1011 close to the near-ground end 101a and the remote-ground end 101b of the shaft 101, respectively, are connected to two ends of the first rail 102 extending into the shaft 101, so that the nutrient solution flows in the first channel 1020 of the first rail 102 can eventually flow into the pipe 1011, and when drawn up to the top of the pipe 1011, can flow into the first channel 1020 of the first rail 102 again, thereby repeating irrigation of the nutrient solution as described previously.

According to a preferred mode, the curvature at any site on the curved second rail 103 continuously decrease as its distance to the shaft 101 increase. In other words, the curvature of the second rail 103 continuously decreases in its extending direction. Preferably, due to the gravity, the nutrient solution flows in the extending direction of the second channel 1030. During its advance, plants in the cultivation portion P at the top of the second rail 103 contact the nutrient solution first, and then the nutrient solution contact plants in the cultivation portion P below the second rail 103. Since the curvature of the second rail 103 continuously decreases, the nutrient solution will stay longer in the cultivation portion P at the top of the second rail 103 because the large curvature helps retain the nutrient solution to some extent, which means it contact the plants in the top cultivation portion P longer, thereby allowing the plants to absorb the nutrient in the nutrient solution effectively. As the curvature continuously decreases in the extending direction of the second rail 103, the flow rate of the nutrient solution increases gradually, and the time it contacts the plants in the cultivation portion P at the bottom of the second rail 103 decrease gradually. A part of the nutrient solution in the cultivation portion P at the top of the second rail 103 may keep flowing down because the capacity of the cultivation portion P available for the nutrient solution is limited, or the retaining effect provided by the curvature features is limited. This makes some nutrient solution in the top cultivation portion P keep flowing downward, so as to replenish the bottom cultivation portion P with the nutrient solution, and prevent the concentration of the nutrient solution from becoming excessively high and causing seedling wilting among the plants in the bottom cultivation portion P.

According to a preferred mode, as shown in FIG. 10, the management system 2 for adjusting the cultivation environment in the plant factory may comprise a managing device 201 that is outside the plant factory and serves to drive or adjust the cultivation environment in the plant factory, a first communication device 202 outside the plant factory, as well as a second communication device 203, an operation device 204, a transceiver device 205, an imaging device 206, a power device 207, a regulator device 208, a second detecting device 209, a first detecting device 210, and a lighting device 21, all located inside the plant factory. Therein, the lighting device 21 at least comprises the first lighting portion 21a and the second lighting portion 21b as described previously. Preferably, the managing device 201 may be any one or a combination of terminals like a desktop computer, a tablet computer, and a smartphone. Preferably, the managing device 201 can be used to set and execute the modulation program of the management system 2, to control the operation of the imaging device 206, to real-time check the environment image information of the plant factory uploaded by the imaging device 206, and to adjust the lighting posture, proportions of light sources, and lighting intensity of the lighting device 21 installed on the plant cultivation shelf 10 according to the real-time growing states of the plants in the plant factory.

According to a preferred mode, the first communication device 202 may be a local area network (LAN) device, and the second communication device 203 may be a wired/wireless router. The transceiver device 205 may be a gateway server. The imaging device 206 may be one or a combination of a video camera, a still camera, and other photography devices. The power device 207 serves to power the other devices in its system. The regulator device 208 serves to adjust the irradiating state of the lighting device 21. The second detecting device 209 serves to detect the current or voltage of electric energy output by the power device 207 to the other devices in the system. The first detecting device 210 comprises plural sensors for detecting parameters in the plant factory, such as the air humidity, the temperature, the lighting intensity, the CO ₂ concentration, the O ₂ concentration, the current, and the voltage. These devices can all be connected in a wired or wireless manner.

According to a preferred mode, the managing device 201 may analyze the image or digital information collected from, for example, the imaging device 206, the second detecting device 209, or the first detecting device 210, so as to identify the cultivation environment in the plant factory and the growing states of the cultivated plants. Preferably, After the first detecting device 210 uploads parameter information of the plant factory such as the air humidity, the temperature, the lighting intensity, the CO ₂ concentration and the O ₂ concentration to the managing device 201 through the network, if any parameter fails to meet the expected goal or exceed a preset threshold, it may suggest that the cultivation environment currently in the plant factory is not ideal for promotion of plant growth. In this case, an administrator of the plant factory may be notified and then use the operation device 204 to adjust the parameters of, for example, fresh air equipment and temperature managing equipment, so as to restore the good cultivation environment for the plant factory. Or, after the imaging device 206 uploads image information about the growing states of the plants, such as the growth heights and the leaf sizes, to the managing device 201, if any parameter fails to meet the expected goal or exceed a preset threshold, it may suggest that the lighting conditions for the plants in the plant factory is not optimal. In this case, an administrator of the plant factory may be notified and then use the operation device 204 to adjust the relevant parameters of the lighting device 21, so as to change the proportions of light sources and the lighting intensity of the lighting device 21, thereby providing lighting most favorable to the plants in the plant factory.

According to a preferred mode, the first communication device 202 serves to establish communication connection between the managing device 201 located in the plant factory and the second communication device 203 located outside the plant factory. Preferably, the first communication device 202 is wired or wireless. The second communication device 203 serves to realize wired/wireless transmission and signal conversion between the managing device 201 and the operation device 204, or managing device 201, or the imaging device 206. Preferably, the second communication device 203 can search for any available operation device 204 and imaging device 206 in the plant factory, and connect thereto.

According to a preferred mode, the operation device 204 may be a computer device located in the plant factory. Further, the operation device 204 has its memory storing modulation information about parameters such as the air humidity, the temperature, the lighting intensity, the CO ₂ concentration, the current, and the voltage. Preferably, different kinds of modulation information can be sent to the regulator device 208, the second detecting device 209, and the first detecting device 210 by the operation device 204. Specifically, an administrator may according to the instruction he/she received from the managing device 201, use the operation device 204 to select modulation information that meets different modulation requirements, and using the transceiver device 205 to send the information to the regulator device 208, the second detecting device 209, or the first detecting device 210.

According to a preferred mode, the transceiver device 205 can receive the modulation information of the operation device 204, and further send the modulation information to the regulator device 208, the second detecting device 209, or the first detecting device 210. Preferably, the transceiver device 205 sends modulation data about the wavelength and the lighting intensity to the regulator device 208, for the latter to adjust the lighting device 21 in terms of lighting posture and light-emitting property. The transceiver device 205 sends modulation data about the current and the voltage to the second detecting device 209, for the latter to adjust the power device 207 in terms of electric output. The transceiver device 205 sends modulation data about the temperature and the humidity to the first detecting device 210, so as to maintain a stable cultivation environment according in the plant factory to the modulation data.

According to a preferred mode, adjustment of light-emitting properties of the lighting device 21, such as the emission wavelength and the lighting intensity, according to the modulation information performed by the regulator device 208 may be achieved by adjusting the pulse voltages supplied by the power device 207 to the lighting device 21. Specifically, the pulse voltages supplied by the power device 207 to the lighting device 21 may be divided into at least two wavebands. The first waveband may be a voltage-varying waveband where the voltage value decreases from the preset value to almost zero, and the second waveband may be a no-voltage waveband. The light-emitting units in the first lighting portion 21a and/or the second lighting portion 21b can adjust the lighting duration, the lighting intensity, the proportions of light sources and/or the lighting curve pattern in response to the voltage variation and/or the current variation of the first waveband, so as to emit the controllable light. Further, the light-emitting units in the first lighting portion 21a and/or the second lighting portion 21b can generate the controllable light having its lighting intensity/illumination close to or equal to zero candela in response to the no-voltage state of the second waveband.

According to a preferred mode, the pulse period may be further divided into three wavebands. The first waveband is a constant voltage waveband or voltage-varying waveband. The second waveband is a voltage-varying waveband where the voltage changes continuously from the voltage value of the waveband to almost zero. The third waveband is a no-voltage waveband. Therein, the voltage variation, the lighting duration, and the spectral variation of the first waveband and the second waveband are controllable. The lighting device 21 emit the first controllable light in response to the voltage variation and/or current variation of the first waveband according to a set of parameters including at least one of the lighting intensities, the lighting duration, the light-emitting spectrum, and the light-emitting curve. In other words, the light of the first waveband may be light of constant lighting intensity, or may be light of varying lighting intensity. Preferably, the specific irradiating state of the lighting device 21 is adjusted according to factors like spatial locations of the plants in the cultivation device 1 and real-time growing states of the plants, so that the periodic light variation of the lighting device 21 matches the growth needs of the plants. Further, through adjustment of voltages, the light-emitting cycle can be regularly adjusted, so as to change one or several parameters of the lighting device 21 such as the lighting duration, the lighting intensity, and/or the proportions of light sources, thereby customizing the flicker specific to the properties of the plants, accelerating plant growth, optimizing growing states of plants, and maximizing economic profits.

According to a preferred mode, the imaging device 206 can using the remote modulation functions of the managing device 201 to monitor the growing states of plants and operation states of the lighting device 21 in the plant factory in a real-time manner, and send the collected image data to the managing device 201. Further, in the event of abnormal growing states of plants or abnormal operation states of the lighting device in the plant factory, the managing device 201 may alarm and prompt an administrator to timely adjust the postures of the plants in the cultivation shelf 10 or investigate, repair, or replace the lighting device 21.

According to a preferred mode, the second detecting device 209 generates power information by performing analog to digital conversion on the current or voltage of the electric energy output by the power device 207 to other devices in the system, such as the regulator device 208 and the lighting device 21, and sends the power information to the managing device 201 through the second communication device 203 and the transceiver device 205 successively. The managing device 201 generates power adjustment data according to the power information through analysis and computation, and sends the power adjustment data to the operation device 204. An administrator then can send the power adjustment data sent to the operation device 204 to the second detecting device 209 through the transceiver device 205, and reset the power output properties of the power device 207 according to the power adjustment data. Preferably, this can significantly decrease output loss of the power device and improve electricity efficiency, thereby reducing waste of resources. Meanwhile, the saved electric energy may be used by the imaging device 206 for state monitoring of the plant factory, or may be used by the first detecting device 210 for measurement of environment parameters of the plant factory, or may be used by the lighting device 21 to provide supplementary lighting to the plants.

Claims

A multi-stage periodic light-emitting apparatus for agricultural lighting, comprising: a cultivation device (1) for carrying or accommodating agricultural products, and a lighting device (21) for providing lighting to the agricultural products cultivated in the cultivation device (1) , wherein

the lighting device (21) has a first lighting portion (21a) made as a linear light source that is configured to, when driven by a rotating component, perform dynamic scanning on the agricultural products cultivated in the cultivation device (1) , wherein spaced growing areas are defined in the cultivation device (1) for the agricultural products, so that the first lighting portion (21a) provides lighting covering the growing areas having the agricultural products while performing the dynamic scanning.
The multi-stage periodic light-emitting apparatus of claim 1, wherein the first lighting portion (21a) is at least able to adjust an irradiating posture by which it irradiates plants in the cultivation device (1) and/or light quality of the corresponding light source through an external drive, and the external drive associates monitoring data of a growing state and/or a growing environment of the plants through an external detecting device with preset thresholds, wherein the first lighting portion (21a) is at least able to swing against a shaft (101) and rotate about the shaft (101) by means of an external drive, and/or to adjust light source proportions of each light-emitting unit through an external drive.
The multi-stage periodic light-emitting apparatus of claim 2, wherein the cultivation device (1) comprises first rails (102) and second rails (103) arranged coaxially, wherein at least one of the first rails (102) extends from a remote-ground end (101b) to a near-ground end (101a) of the shaft (101) and spirals about the shaft (101) of the cultivation device (1) , the first rail (102) having a curve radius changing gradually in a direction in which it extends from the remote-ground end (101b) to the near-ground end (101a) of the shaft (101) ; and wherein plural said second rails (103) are such distributed on a peripheral surface of the shaft (101) that adjacent said second rails (103) are staggered from each other according to set gaps provided in a first direction and/or a second direction, the plural second rails (103) arranged axially/radially along the shaft (101) having lengths that are different from each other; and wherein the first rails (102) and the second rails (103) intersect each other so as to form plural cultivation portions (P) for cultivating the plants such that adjacent said cultivation portions (P) are staggered from each other.
The multi-stage periodic light-emitting apparatus of claim 3, wherein at least one said first rail (102) that extends axially along the shaft (101) and spirals about the shaft (101) is arranged on a peripheral surface of the shaft (101) by means of preset gaps configured in a first direction and/or a second direction, and, based on the gaps, plural said first rails (102) form cultivation layers separated by layer distances that are not completely equal.
The multi-stage periodic light-emitting apparatus of claim 4, wherein the second rail (103) is positioned inclined so that a nutrient solution for nourishing the plants flows down by gravity, thereby reaching the plants in the cultivation portions (P) from above, wherein a curvature at any point on the second rail (103) gradually decreases as its distance from the shaft (101) increases, and a flow rate of the nutrient solution that flows in an extending direction of the second rail (103) gradually increase as the curvature of the second rail (103) gradually decreases.
The multi-stage periodic light-emitting apparatus of claim 5, further comprising a pipe (1011) for delivering the nutrient solution that is received in a hollow channel (1010) of the shaft (101) , wherein the pipe (1011) has plural outlets (1012) such formed on a radially outer lateral surface of the pipe (1011) that adjacent said outlets (1012) are staggered from each other, and two ends of the pipe (1011) are connected to two ends of the first rail (102) extending into the shaft (101) , respectively, wherein each said outlet (1012) is communicated with one end of the second rail (103) extending into the shaft (101) .
The multi-stage periodic light-emitting apparatus of claim 6, wherein the multi-stage periodic light-emitting apparatus is applicable to a management system (2) that at least comprises: a managing device (201) for receiving state detection data of a plant factory and distributing corresponding modulation data to other devices; an imaging device (206) for monitoring growing states of plants in the plant factory and sending image information about the growing states of the plants to a managing device (201) that generates the modulation data accordingly; a first detecting device (210) for detecting plural parameters about a cultivation environment in the plant factory and transmitting information of the plural parameters to the managing device (201) that generates the modulation data accordingly; and an operation device (204) for calling and distributing, in response to instructions from the managing device (201) , the modulation information kept therein.
The multi-stage periodic light-emitting apparatus of claim 7, wherein the management system (2) further comprises a transceiver device (205) and an adjusting module (208) , the transceiver device (205) serving to receive detection information uploaded by the imaging device (206) and/or the first detecting device (210) and send them to the managing device (201) , and to receive the modulation information that is distributed to the operation device (204) by the managing device (201) and send it to the first detecting device (210) and all the other devices except for itself; the adjusting module (208) serving to receive the modulation information distributed by the transceiver device (205) , and according to the modulation information, adjust the irradiating postures and/or the light qualities of the corresponding light sources for the first lighting portion (21a) and/or a second lighting portion (21b) to provide the supplementary lighting.
A multi-stage periodic light-emitting apparatus for agricultural lighting, comprising: a cultivation device (1) for carrying or accommodating agricultural products, and a lighting device (21) for proving lighting to the agricultural products in the cultivation device (1) , wherein

the lighting device (21) serves to provide controllable light that has changeable lighting intensity/illumination to the agricultural products in the cultivation device (1) in response to input of an adjustable pulse voltage, wherein the pulse voltage has a pulse period that can be divided into at least two stages, wherein at least one of the stages is a voltage-varying stage where a voltage value changes from a set value to a zero voltage, and at least one of the stages is a no-voltage stages.
The multi-stage periodic light-emitting apparatus of claim 9, wherein when the voltage value of the pulse period is in the voltage-varying stage, the lighting device (21) provides the controllable light by adjusting lighting duration, the lighting intensity and/or proportions of the light sources of the corresponding light-emitting unit according to voltage variation and/or current variation.
The multi-stage periodic light-emitting apparatus of claim 10, wherein when the voltage value of the pulse period is in the no-voltage stage, the lighting device (21) generates the controllable light having the lighting intensity/illumination close to or equal to zero candela according to a no-voltage state.
The multi-stage periodic light-emitting apparatus of claim 11, wherein the pulse period can be divided into three wavebands, in which a first waveband is a constant voltage waveband or a voltage-varying waveband, and a second waveband is a voltage-varying waveband where the voltage value continuously changes from the constant waveband to the zero voltage, while a third waveband is a no-voltage waveband, wherein in the first waveband and the second waveband, the voltage variation, the lighting duration, and spectral variation are controllable.
The multi-stage periodic light-emitting apparatus of claim 12, wherein the lighting device (21) , in response to the voltage variation and/or the current variation in the first waveband, according to a set of parameters of at least one of the lighting intensity, the lighting duration, a light-emitting spectrum, and a light-emitting curve, emits a first controllable light; in response to the voltage variation and/or the current variation in the second waveband, according to a set of parameters of at least one of the lighting intensity, the lighting duration, and the light-emitting spectrum, emits a second controllable light whose lighting intensity/illumination showing a declining trend; in response to the no-voltage state in the third waveband, generates a third controllable light whose lighting intensity close to or equal to zero candela.
The multi-stage periodic light-emitting apparatus of claim 1, wherein the lighting device (21) comprises the first lighting portion (21a) having a linear shape and the second lighting portion (21b) having a circular shape, both installed on the shaft (101) of the cultivation device (1) , wherein the first lighting portion (21a) and the second lighting portion (21b) each are formed by plural light-emitting modules (210) that are configured to be driven independently.
A multi-stage periodic light-emitting lighting method for agricultural lighting, which uses the multi-stage periodic light-emitting apparatus of any of the preceding claims, wherein the method at least comprises adjusting a specific irradiating state of the lighting device (21) according to factors about spatial locations and real-time growing states of agricultural products in the cultivation device (1) , so that a periodic light profile of the lighting devices (21) matches growth needs of the plants.