JP2019198256A - Plant cultivation device - Google Patents

Abstract

To provide a plant cultivation device that can irradiate leaf surfaces of plants with appropriate light volume.SOLUTION: A plant cultivation device comprises: a planting part 4 into which plants 1 are planted; a light irradiation part 3 which irradiates the planting part 4 with light from a first direction; and an intensity setting part 31 which increases a preset value of the irradiation intensity of the light irradiation part 3 as exposure rate, in which the planting part 4 is not covered by the plants 1 but exposed in the case of seeing from the first direction, becomes smaller.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a plant cultivation apparatus for cultivating a plant by irradiating the plant with light emitted from an artificial light source in a room such as a plant factory.

  Development of artificial light type plant cultivation device (hereinafter also simply referred to as “device”) that irradiates plants with artificial light generated using artificial light sources such as LEDs (Light Emitting Diode) as light necessary for cultivation Is underway. Many devices have been devised in order to efficiently use artificial light. Specifically, for example, a space including a ground part of a plant (a part above the ground surface part where the plant is planted; hereinafter referred to as “plant ground part”) is surrounded by a reflector, or the ground surface part is white. There is an idea to make it with a material that reflects light well, such as polystyrene foam.

The growth of the above-ground part of the plant is largely divided into horizontal development (growth) and height extension (growth). In a plant cultivation apparatus that grows plants by irradiation of artificial light, the following phenomenon occurs as the two grow.
(Phenomenon 1) When the plant ground part (mainly leaves) expands in the horizontal direction, the ground surface part of the plant cultivation device is covered, and the reflected light in the space including the plant ground part is reduced and darkened. The amount of light applied to the leaf surface is reduced.
(Phenomenon 2) As the height of the plant increases, the distance between the plant and the artificial light source decreases, and the amount of light applied to the leaf surface increases.

  The former (Phenomenon 1) causes a decrease in the photosynthetic rate of the plant, and can lead to a slowdown in plant growth. The growth rate of the plant affects Nissan of the plant cultivation device, and thus greatly affects the production cost. For this reason, slowing down of plant growth is an important issue for users of plant cultivation apparatuses.

  On the other hand, the latter (Phenomenon 2) increases leaf photorespiration by irradiating excessive artificial light and induces growth failure. As a result, more power is wasted than necessary, which is also a production cost. Influences.

  That is, the amount of light with respect to the leaf surface needs to be adjusted in consideration of the degree of two growths (horizontal expansion and height extension).

  In order to solve the latter problem (Phenomenon 2), Patent Document 1 obtains information on the height of a plant during imaging while the plant is growing, and sets the amount of light to be irradiated from that information. However, a technique is disclosed in which the light amount detecting unit fixed in the apparatus adjusts the light amount until it shows the same value as the target value.

International Publication No. 2017/002321

  However, the technique disclosed in Patent Document 1 is intended only to solve the problem of the latter (phenomenon 2), and it takes into account the reduction in the amount of light on the foliage caused by the horizontal growth of the plant ground part. Not. For this reason, there is a possibility that the amount of light on the leaf surface becomes inappropriate during the plant growth process.

  Moreover, when using the technique disclosed in Patent Document 1 for plants in which the above-ground part such as leafy vegetables such as lettuce grows greatly, a design problem arises in order to provide a fixed light amount detection part. That is, the light amount detection unit must be fixed at an appropriate position so as not to contact the plant being cultivated, to enter the shade of the plant, and to be correlated with the light amount to the leaf surface.

  However, when cultivating a large amount of plants where the above-ground part grows, especially when it is assumed that the same specification device is applied to a plurality of plants having different shapes, the light amount detection as described above. The position of the part is substantially difficult. That is, in a plurality of plants having different shapes, the appropriate positions of the light amount detection units are different from each other, and it is difficult to appropriately detect the light amount to the leaf surface of plants having different shapes by the light amount detection unit having a fixed position. is there. For this reason, plants to which the technique disclosed in Patent Document 1 can be applied are limited by the shape of the above-ground part.

  This invention solves such a subject, and it aims at providing the plant cultivation apparatus which enabled the suitable light quantity to be irradiated to the leaf surface of a plant.

  In order to achieve the above object, a plant cultivation apparatus according to the present invention includes a planting unit in which a plant is planted, a light irradiation unit that irradiates light from a first direction to the planting unit, and a view from the first direction. And an intensity setting unit that increases the set value ISx of the irradiation intensity of the light irradiation unit as the exposure rate Px at which the planted part is exposed without being covered with the plant is reduced.

  According to the present invention, it is possible to adjust the irradiation intensity of the light irradiation unit so that the amount of light irradiated on the leaf surface becomes the target amount of light after considering the growth in the horizontal direction of the plant. It is possible to irradiate the light with no excess or deficiency.

Sectional schematic diagram for demonstrating the whole structure of the plant cultivation apparatus in Embodiment 1 of this invention. It is a schematic diagram for demonstrating the imaging range of the vertical imaging part of the plant cultivation apparatus in Embodiment 1 of this invention, Comprising: The top view of a ground surface part The schematic diagram which looked at the ground space of the plant cultivation apparatus in Embodiment 1 of this invention from the imaging direction of the horizontal imaging part. The figure which shows the relationship between the elapsed time after starting cultivation of a plant, and the exposure rate of a ground surface part The figure which shows the relationship between the elapsed time from the start of plant cultivation and the amount of ground space light The figure which shows the relationship between the ground surface part exposure rate and the ground space light quantity The figure which shows the relationship between the distance from a light irradiation part, and leaf surface light quantity The figure which shows the irradiation intensity setting value with respect to cultivation elapsed time The figure which shows the correlation with cultivation elapsed time and leaf light quantity Functional block diagram of the control unit of the plant cultivation apparatus in Embodiment 1 of the present invention The flowchart for demonstrating the determination process of the irradiation intensity setting value in Embodiment 1 of this invention Functional block diagram of the control unit of the plant cultivation apparatus in Embodiment 2 of the present invention The flowchart for demonstrating the determination process of the irradiation intensity setting value in Embodiment 2 of this invention

  Hereinafter, a plant cultivation apparatus according to an embodiment of the present invention will be described with reference to the drawings. Each embodiment described below is merely an example, and does not exclude various modifications and technical applications that are not clearly described in each embodiment below. In addition, each configuration of each embodiment can be implemented with various modifications without departing from the spirit thereof. Furthermore, each structure of each embodiment can be selected as needed, or can be combined suitably.

  Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the description thereof may be omitted.

[1. Embodiment 1]
[1-1. Plants cultivated with plant cultivation equipment]
FIG. 1 is a schematic cross-sectional view for explaining the overall configuration of the plant cultivation apparatus 100 according to Embodiment 1 of the present invention. Examples of the plant 1 cultivated using the plant cultivation apparatus 100 shown in FIG. 1 include leaf vegetables such as lettuce. However, the plant 1 that can be cultivated by the plant cultivation apparatus 100 is not limited to this, and is mainly a plant in a vegetative growth stage, and its ground part (cultivation target part, here mainly a leaf). (Hereinafter also referred to as “plant above-ground part”) is edible and hydroponically cultivated.

[1-2. Overall configuration of plant cultivation equipment]
As shown in FIG. 1, the plant cultivation apparatus 100 according to Embodiment 1 is installed in a housing 200 that forms a sealed space. The housing 200 is provided with a door (not shown), and a person who performs cultivation work can open and close the door 200 by opening and closing the door.

  The plant cultivation device 100 is divided into a ground space 21 (cultivation space) and an underground space 25 by the ground surface portion 4 (planting portion).

The ground surface portion 4 is a plant in which plants are planted and is a plate-like one having a through hole 4A, and is made of a material that easily reflects irradiated light, such as white polystyrene foam. The culture medium 41 is inserted into the through hole 4A. The culture medium 41 is composed of a sponge or the like that can retain permeated moisture. In the plant 1, the culture medium 41 that wraps a part of the underground part (hereinafter also referred to as “plant underground part”) 1 </ b> B disposed mainly in the underground space 25 is inserted into the through-hole 4 </ b> A. It is fixed to the surface part 4.

  The underground space 25 is configured by the cultivation tank 5. The cultivation tank 5 is filled with a culture solution 8. The culture solution 8 is supplied from the tank 11 to the cultivation tank 5 through the supply pipe 5A by the power of the pump 12, and is further returned from the cultivation tank 5 to the tank 11 through the discharge pipe 5B. That is, the culture solution 8 circulates between the cultivation tank 5 and the tank 11.

  In addition, although the plant cultivation apparatus 100 of this Embodiment 1 has shown as an example what applied to DFT (Deep Flow Technique), this invention is not limited to application to DFT. The present invention can also be applied to, for example, NFT (Nutrient Film Technique).

  The ground space 21 is configured such that the upper part is surrounded by the upper surface reflection plate 6 and the side part is surrounded by the side surface reflection plate 7. A light irradiation unit 3 (a pair in the first embodiment) is fixed to the surface of the upper surface reflecting plate 6 toward the ground space 21 via an illumination support unit 35. The light irradiation part 3 irradiates light (artificial light) to the plant ground part 1A.

  The plant cultivation apparatus 100 includes a vertical imaging unit 91 (first imaging unit) that images the ground surface portion 4 from above the plant ground portion 1A (from the first direction). The vertical imaging unit 91 is fixed to the lower surface of the upper surface reflector 6. In the first embodiment, between the pair of light irradiation units 3, it is arranged at the center in the width direction (the center in the left-right direction in FIG. 1) of the lower surface of the upper reflector 6.

  FIG. 2 is a plan view of ground surface portion 4 in the first embodiment of the present invention. A vertical imaging unit imaging range (hereinafter, also simply referred to as “imaging range”) 92 illustrated in FIG. 2 is an imaging range of the vertical imaging unit 91. That is, the imaging range 92 is a range of image data (imaging information) acquired by the vertical imaging unit 91.

  The imaging range 92 is preferably set so as to include all of the plurality of individual plant ground portions 1A planted on the ground surface portion 4 so as to include at least one individual plant ground portion 1A. 4 is set as a range over the whole of 4 or a range over only a part of the ground surface portion 4

  As shown in FIG. 1, the plant cultivation apparatus 100 further includes a horizontal imaging unit 95 (second imaging unit) that images the ground space 21 and thus the plant ground part 1A from the horizontal direction (second direction intersecting the first direction). I have. The horizontal imaging unit 95 is fixed to the inner side surface of the side reflector 7.

  The horizontal imaging unit 95 will be further described with reference to FIG. FIG. 3 is a schematic view of the ground space 21 viewed from the imaging direction of the horizontal imaging unit 95. As shown in FIG. 3, the horizontal imaging unit 95 obtains image data (imaging information) in a range including the height hx of the plant 1 (specifically, the height of the plant ground part 1A based on the upper surface of the ground surface part 4). To do. Note that the symbol “H” in FIG. 3 indicates the distance between the ground surface portion 4 and the light irradiation portion 3.

  Each of the vertical imaging unit 91 and the horizontal imaging unit 95 is a video camera that is generally used. However, the vertical imaging unit 91 and the horizontal imaging unit 95 are not limited to video cameras as long as they can identify the plant 1 from surrounding objects, and may be infrared cameras, for example.

  The plant cultivation apparatus 100 further includes a control unit 30 as shown in FIG. The control unit 30 acquires the image data from the vertical imaging unit 91 and the horizontal imaging unit 95, detects the ground surface portion exposure rate Px from the image data of the vertical imaging unit 91, and the image of the horizontal imaging unit 95, as will be described later. The height hx is detected from the data.

[1-3. Configuration of control unit and method for determining irradiation intensity setting value]
The control unit 30 is a computer in which a program for executing control of the light irradiation unit 3 is installed. As shown in FIG. 1, the control unit 30 includes an intensity setting unit 31 and an illumination adjustment unit 32.

  The intensity setting unit 31 calculates the irradiation intensity setting value ISx of the light irradiation unit 3 at each point in the growth process of the plant 1, that is, at an arbitrary point after the start of cultivation of the plant 1 by the plant cultivation apparatus 100, using the following formula (1 ).

  Height hx, ground surface exposure rate (hereinafter also referred to as “exposure rate”) Px, distance H, reference height ha, target light amount Ia, reference area rate Pa, reference light amount If, and reference irradiation intensity La in this formula (1) Is as shown in the table below.

  That is, the height hx is the height of the plant ground portion 1A as described above (see FIG. 3). The exposure rate Px is a ratio of the area of the ground surface portion 4 that is exposed without being covered by the plant 1, and more specifically, the area (imaging area) of the imaging range 92 (see FIG. 2) of the vertical imaging unit 91. It is a ratio of the area (exposed area) of the ground surface part 4 exposed without being covered with the plant 1 with respect to. The distance H is the distance (see FIG. 3) between the light irradiation part 3 and the ground surface part 4 as described above. The reference height ha is the height hx of the plant ground portion 1A at a reference elapsed time Ta (hereinafter also referred to as “reference time Ta”). The target light amount Ia is the ground space light amount at the reference time Ta among the light amount (hereinafter also referred to as “ground space light amount”) Ix measured at the reference height ha. The reference exposure rate Pa is the exposure rate Px at the reference time Ta. The reference irradiation intensity La is the irradiation intensity setting value ISx of the light irradiation unit 3 at the reference time Ta. The reference light amount If is the ground space light amount Ix when the exposure rate Px is 0 (zero). A method for determining the reference time Ta will be described later.

  By determining using the above equation (1), the irradiation intensity setting value ISx is set to a higher value as the exposure rate Px is lower, and is set to a lower value as the height hx of the ground space portion 1A of the plant 1 is higher. Is set.

  Hereinafter, the above formula (1) will be further described.

  The hatched portion in FIG. 2 indicates an exposed portion of the ground surface portion 4 that is not covered with the plant ground portion 1A when viewed from the vertical imaging unit 91. The ratio of the area A1 of the exposed portion within the predetermined range of the ground surface portion 4 to the area A0 of the predetermined range is the ground surface portion exposure rate Px (= A1 / A0). In the first embodiment, the predetermined range is the imaging range 92. The exposure rate Px is a value that decreases as the plant ground portion 1A grows in the horizontal direction, that is, expands leaves, and eventually becomes 0 (zero).

  FIG. 4 is a diagram showing the relationship between the elapsed time (hereinafter also referred to as “cultivated elapsed time”) Tx after the cultivation of the plant 1 is started and the exposure rate Px. As shown in FIG. 4, the exposure rate Px decreases linearly as the elapsed time Tx progresses until the elapsed time Tx reaches the elapsed time Tf at which Px = 0. Here, the exposure rate Px at the reference time Ta is set to the target exposure rate Pa as described above. The reference time Ta is a time point belonging to a period Y from the start of cultivation of the plant 1 until the exposure rate Px becomes 0 (zero). The reference time Ta is obtained by measuring the exposure rate Px, the ground space light amount Ix, and the height hx of the plant ground portion 1A (that is, the reference exposure rate Pa, the target light amount Ia, and the reference height ha) within the range of the period Y. The time point that can be obtained by analysis may be arbitrarily selected.

  However, when the exposure rate Px is detected from the image data of the vertical imaging unit 91, since the error in the detection value of the exposure rate Px is large, the time when the exposure rate Px becomes a value close to 100% or 0% at the reference time Ta. Selecting is not recommended. In the first embodiment, the detection accuracy of the exposure rate Px allowable within the range of 10% ≦ Px ≦ 90% was confirmed. In the first embodiment, the reference time Ta is set to 1 day after the start of cultivation, and the exposure rate Px at the reference time Ta, that is, the reference exposure rate Pa is about 80%.

  In FIG. 5, the relationship between the elapsed time Tx after starting cultivation of the plant 1 and the ground space light quantity Ix is shown. This ground space light quantity Ix is the light quantity of the ground space 21 measured at the reference height ha as described above. In other words, the amount of ground space light Ix is a value measured at a certain distance H-ha from the light irradiation unit 3. The amount of ground space light Ix is measured in a state where there is no shield between the light irradiation unit 3 and the measurement point. The ground space light quantity Ix decreases linearly as the elapsed time Tx advances until the elapsed time Tf, and shows a substantially constant value after the elapsed time Tf. As described above, the ground space light amount Ix at the elapsed time Tf is the reference light amount If in the above equation (1).

  FIG. 6 shows the relationship between the exposure rate Px and the ground space light quantity Ix. The exposure rate Px and the ground space light quantity Ix have a linear correlation.

  In addition, FIG.4, FIG.5 and FIG.6 has shown the result at the time of growing the frill lettuce (brand name frill ice, Snow Brand Seed Seed Co., Ltd.) as the plant 1 as an example. When other varieties are cultivated as the plant 1, the correlation of the exposure rate Px to the elapsed time Tx shown in FIG. 4 and the correlation of the ground space light quantity Ix to the elapsed time Tx shown in FIG. Before time Tf, the tendency may be different (the outline of the correlation line representing the correlation may be different).

  For example, when a green leaf (trade name Green Jacket, Nakahara Seed Co., Ltd.) is cultivated as a plant 1, the correlation line of the ground surface exposure rate Px with respect to the elapsed time Tx as shown in FIG. 4 is before the elapsed time Tf. Then, it became a monotonically decreasing line approximating an upward convex quadratic curve. The correlation line of the ground space light quantity Ix with respect to the elapsed time Tx as shown in FIG. 5 is a monotonically decreasing line approximating a downwardly convex quadratic curve before the elapsed time Tf.

  However, as for the relationship between the exposure rate Px and the amount of ground space light Ix, even when the green leaf was cultivated as the plant 1, a linear correlation was obtained as in the frill lettuce shown in FIG. That is, depending on the variety of the plant 1 as the ground surface portion 4 is covered with leaves and the exposed portion of the ground surface portion 4 decreases due to the horizontal growth of the plant ground portion 1A (that is, the development of the leaves). The ground space light quantity Ix decreases linearly. That is, the relationship between the exposure rate Px and the ground space light quantity Ix is expressed by a linear curve (linear function) having different slopes and intercepts.

  In FIG. 7, the distance D (= H-hx, refer FIG. 3) from the light irradiation part 3 in the plant cultivation apparatus 100, and the light quantity irradiated to a leaf surface (henceforth "the leaf surface light quantity"). The relationship with LIx is shown. As shown in FIG. 7, generally, the leaf surface light quantity LIx decreases in inverse proportion to the square of the distance D from the light source to the leaf surface.

  In view of the correlation shown in FIGS. 6 and 7 above, the leaf surface light quantity LIx at any cultivation elapsed time Tx when the irradiation intensity is constant from the initial stage (cultivation start) is the distance H, the exposure rate Pa, It is expressed by the following equation (2) using Px, target light amount Ia, height ha, hx, and reference light amount If.

  As described above, the ground space light amount Ix is a light amount at the height hx (= reference height ha) at the reference time Ta. That is, for example, if the reference height ha is 10 cm, the height 10 cm above the ground surface portion 4 is a fixed measurement height, and the light quantity at this measurement height is the ground space light quantity Ix. At the reference time Ta, the leaf surface height is the height ha (for example, 10 cm), so the leaf surface light amount LIx at the reference time Ta is the ground space light amount Ix at the reference height ha (for example, 10 cm), that is, the target light amount Ia. It becomes itself.

  In order to make the leaf surface light amount constant at the arbitrary time point Tx so as to be the leaf surface light amount (that is, the target light amount Ia) at the reference time Ta, the irradiation intensity setting value ISx is determined by the above equation (3). do it. That is, the irradiation is performed by multiplying the reference irradiation intensity La by the reciprocal (= LIx / Ia) of the ratio between “the leaf surface light intensity LIx when the irradiation intensity is constant” expressed by the above formula (2) and the target light intensity Ia. What is necessary is just to obtain | require intensity setting value ISx.

  Then, by substituting the calculation formula of the leaf surface light amount LIx in the above equation (2) into the leaf surface light amount LIx in the above equation (3), the target surface light amount is irradiated on the leaf surface in an arbitrary cultivation elapsed time Tx. The irradiation intensity setting value ISx for doing so is expressed by the above equation (1).

  It should be noted that the above formula (1) and the above formula (2) are not guaranteed to be common among plants and cultivation environments of all varieties, and the varieties and cultivation environments of the plants 1 cultivated by the plant cultivation apparatus 100 It may be different depending on the situation. For this reason, when the kind and cultivation environment of the plant 1 differ greatly, before implementing cultivation with the plant cultivation apparatus 100, for each kind of plant 1 and every cultivation environment, the above formula (1) and the above formula (2 ) Needs to be confirmed by experiment. For example, in the above equation (2), the outline of the correlation line indicating the correlation between the exposure rate Px and the ground space light amount Ix shown in FIG. There may be no varieties whose correlation line is not linear. However, even in this case, the first half of the right side of the above equation (2) [(Ia−If) × Px / Pa + If] is represented by the regression curve equation (correlation between the exposure rate Px obtained from the regression analysis and the ground space light quantity Ix. It may be replaced with (formula).

  FIG. 8 shows the irradiation intensity set value ISx obtained by the above equation (1) according to the cultivation elapsed time Tx.

  In contrast, FIG. 9 shows the correlation between the cultivation elapsed time Tx and the leaf surface light amount LIx when the irradiation intensity of the light irradiation unit 3 is constant regardless of the cultivation elapsed time Tx. As is clear from FIG. 9, after the elapsed time Tf when the exposure rate P becomes 0 (zero), as the cultivation elapsed time Tx advances and the height h of the plant 1 increases, the plant ground part 1A and the light irradiation part 3 The distance D between the two becomes shorter, so that the leaf surface light quantity LIx increases and it becomes excessive.

  In addition, the relationship (correlation line) between the cultivation elapsed time Tx and the irradiation intensity setting value ISx shown in FIG. 8 and the relationship (correlation line) between the cultivation elapsed time Tx and the leaf surface light amount LIx shown in FIG. 9 are examples. It is. Depending on the variety of the plant 1 and the light quality of the light irradiation unit 3, such a correlation line is not necessarily in the same shape as that shown in FIG. 8 or FIG. This is because the growth balance between the horizontal direction and the vertical direction of the plant 1 greatly affects the shape of the correlation line as shown in FIGS.

  A description will be given with reference to FIG. 1 again. The illumination adjustment unit 32 adjusts the irradiation intensity of the light irradiation unit 3 based on the irradiation intensity setting value ISx determined by the intensity setting unit 31. That is, if the current irradiation intensity is greater than the irradiation intensity setting value ISx (or if the irradiation intensity is greater than the irradiation intensity setting value ISx by a predetermined intensity or more), the irradiation intensity is reduced to ISx. If the irradiation intensity is smaller than the irradiation intensity setting value ISx (or if the irradiation intensity is smaller than the irradiation intensity setting value ISx by a predetermined intensity or more), the irradiation intensity is increased to the irradiation intensity setting value ISx. As a result, the leaf surface of the plant 1 is always irradiated with the target light amount Ia (or substantially the same light amount as the target light amount Ia).

  The strength setting unit 31 will be further described with reference to FIG. FIG. 10 is a functional block diagram of the control unit 30 of the plant cultivation apparatus 100 according to the first embodiment. As illustrated in FIG. 10, the strength setting unit 31 includes a storage unit 312, a calculation unit 313, an exposure rate detection unit 314, and a height detection unit 315.

  The storage unit 312 stores constants necessary for setting the irradiation intensity setting value ISx based on the above equation (1). Specifically, the storage unit 312 stores the distance H between the light irradiation unit 3 and the ground surface portion 4, the target light amount Ia, the reference exposure rate Pa, the reference height ha, the reference irradiation intensity La, and the reference light amount If. doing.

  The exposure rate detection unit 314 performs image analysis on the image data acquired by the vertical imaging unit 91 and detects the ground surface portion exposure rate Px.

  The height detection unit 315 analyzes the image data acquired by the horizontal imaging unit 95 and detects the height hx of the plant ground portion 1A.

  The calculation unit 313 includes a ground surface portion exposure rate Px detected by the exposure rate detection unit 314, a height hx detected by the height detection unit 315, and constants H, Ia, Pa, ha, La stored in the storage unit 312. , If are substituted into the above equation (1), the irradiation intensity setting value ISx of the light irradiation unit 3 is calculated such that the amount of light on the leaf surface becomes the target value Ia.

[1-4. Irradiation intensity setting value determination process]
With reference to FIG. 11, the irradiation intensity setting value ISx determination process performed by the intensity setting unit 31 in the first embodiment will be described. FIG. 11 is a flowchart for explaining the process for determining the irradiation intensity set value ISx in the first embodiment of the present invention. This determination process is periodically and repeatedly executed while the plant cultivation apparatus 100 is cultivating.

  First, in step S <b> 21, the intensity setting unit 31 causes the exposure rate detection unit 314 to acquire image data obtained by the vertical imaging unit 91 as viewed from the upper side of the ground surface unit 4. In step S22, the intensity setting unit 31 causes the exposure rate detection unit 314 to perform image analysis on the image data acquired in the previous step S22 to detect the exposure rate Px. In step S <b> 23, the intensity setting unit 31 causes the height detection unit 315 to acquire image data captured by the horizontal imaging unit 95 and captured from the side of the plant ground unit 1 </ b> A. In step S24, the strength setting unit 31 causes the height detection unit 315 to perform image analysis on the image data acquired in the previous step S23 to detect the height hx of the plant ground portion 1A. In step S <b> 25, the strength setting unit 31 causes the calculation unit 313 to store the exposure rate Px detected by the exposure rate detection unit 314, the height hx detected by the height detection unit 315, and the constant stored in the storage unit 312. And the irradiation intensity set value ISx is calculated based on the above equation (1).

  Further, in the irradiation intensity setting process of the first embodiment, the process of step S26 is further performed. That is, when the irradiation intensity set value ISx is calculated in step S25, the intensity setting unit 31 refers to the exposure rate Px detected by the exposure rate detection unit 314 in step S26. If the exposure rate Px is not 0 (zero) (Px ≠ 0), the intensity setting unit 31 returns to the process of step S21.

  On the other hand, if Px = 0 in step S26, the strength setting unit 31 returns to the process of step S23. This is because the exposure rate Px decreases as the plant ground portion 1A grows in the horizontal direction, i.e., leaves develop, and once it becomes 0 (zero), then it remains constant until harvest until it reaches 0 (zero). . For this reason, the intensity setting unit 31 does not need to detect the exposure rate Px again by the processes of steps S21 and S22, and proceeds to the process of step S23, bypassing steps S21 and S22.

  And if the determination process of the above irradiation intensity setting value is completed, the illumination adjustment part 32 will adjust the output of the light irradiation part 3 so that it may become irradiation intensity setting value ISx after that.

  Note that step S26 may be omitted, and when the process of step S25 ends, the strength setting unit 31 may return to the process of step S21 constantly.

[1-5. effect]
(1) According to the first embodiment of the present invention, in consideration of not only the vertical growth of the plant 1 but also the growth in the horizontal direction, the light irradiation unit so that the leaf surface light amount LIx becomes the target light amount Ia. The irradiation intensity setting value of 3 can be automatically controlled. Thereby, the change in the amount of light on the leaf surface caused by the growth of the plant can be offset, and an appropriate amount of light can be applied to the leaf surface of the plant.

  (2) Furthermore, since the determination of the irradiation intensity setting value ISx is performed based on the image data from above the plant 1 and the image data from the side of the plant 1, not only the determination of the irradiation intensity setting value ISx. At the same time, based on these image data, it is possible to simultaneously monitor and record the growth state of the plant 1.

[2. Second Embodiment]
[2-1. Configuration of main part (control part) of plant cultivation apparatus]
Hereinafter, the configuration of the control unit 30A, which is a main part of the plant cultivation apparatus according to the second embodiment, will be described with reference to FIG. FIG. 12 is a functional block diagram of the control unit 30A of the plant cultivation apparatus according to Embodiment 2 of the present invention.

  The configuration of the plant cultivation apparatus according to the second embodiment is obtained by replacing the control unit 30 with the control unit 30A shown in FIG. 12 and omitting the horizontal imaging unit 95 with respect to the plant cultivation apparatus 100 according to the first embodiment. Other configurations are the same as those of the plant cultivation apparatus 100 of the first embodiment.

  The plant cultivation apparatus of the second embodiment is useful when there is a correlation between the exposure rate Px and the height hx of the plant ground portion 1A through the entire cultivation process of the plant 1 to be cultivated. That is, it is necessary at least that the exposure rate Px does not reach 0 (zero) throughout the entire cultivation process. Further, it is necessary to obtain in advance a correlation between an arbitrary exposure rate Px and a height hx through experiments and simulations.

  As shown in FIG. 12, the control unit 30A includes an illumination adjustment unit 32 and an intensity setting unit 31A, and the configuration of the intensity setting unit 31A is different from the configuration of the intensity setting unit 31 of the first embodiment. Specifically, the intensity setting unit 31A includes a reference unit 311, a storage unit 312A, a calculation unit 313, and an exposure rate detection unit 314.

  In addition to the constants H, Ia, Pa, ha, La, If, the storage unit 312A includes a data table DT indicating the correlation between the exposure rate Px and the height hx as shown in Table 2 below.

  The reference unit 311 selects the height hx of the plant ground portion 1A based on the exposure rate Px detected by the exposure rate detection unit 314 according to the data table DT. For example, when the exposure rate Px is P1, the height h1 is selected as the height hx. When the exposure rate Px is a value between P1 and P2, for example, the height hx is obtained by interpolating the heights h1 and h2.

  The calculation unit 313 calculates the exposure rate Px detected by the exposure rate detection unit 314, the height hx selected by the reference unit 311 and the constants H, Ia, Pa, ha, La, If stored in the storage unit 312A. Using the above equation (1), the irradiation intensity setting value ISx of the light irradiation unit 3 is calculated such that the leaf surface light amount LIx becomes the target light amount Ia.

  Since other configurations are the same as those of the first embodiment, the description thereof is omitted.

[2-2. Irradiation intensity setting value determination process]
With reference to FIG. 13, the setting process of irradiation intensity setting value ISx performed by intensity setting unit 31A in the second embodiment will be described. FIG. 13 is a flowchart for explaining the irradiation intensity setting value determination process in the second embodiment of the present invention. In addition, this determination process is repeatedly performed periodically while cultivation with a plant cultivation apparatus is implemented.

  First, in step S31, the intensity setting unit 31 causes the exposure rate detection unit 314 to acquire image data obtained by viewing the ground surface portion 4 imaged by the vertical imaging unit 91 from the upper side. In step S32, the intensity setting unit 31 causes the exposure rate detection unit 314 to analyze the image data acquired in the previous step 32 and detect the ground surface portion exposure rate Px. In step S33, the strength setting unit 31 causes the reference unit 311 to refer to the data table DT of the storage unit 312A and selects the height hx of the plant ground portion 1A according to the ground surface portion exposure rate Px. In step S34, the intensity setting unit 31 refers to the calculation unit 313 with the exposure rate Px detected by the exposure rate detection unit 314, the height hx selected by the reference unit 311 and the constant stored in the storage unit 312A. Then, the irradiation intensity set value ISx is calculated based on the above equation (1).

  And the illumination adjustment part 32 adjusts the output of the light irradiation part 3 so that illumination intensity becomes this irradiation intensity setting value ISx.

[2-3. effect]
According to the second embodiment of the present invention, the following effects are obtained in addition to the effects of the first embodiment. That is, since the reference unit 311 refers to the data table DT and selects the height hx of the plant ground portion 1A according to the exposure rate Px, the horizontal imaging unit for detecting the height hx as in the first embodiment. 95 is omitted and the apparatus is simplified.

[2-4. Modified example]
In the second embodiment, the reference unit 311 is provided and the horizontal imaging unit 95 and the height detection unit 315 are omitted from the first embodiment. However, the reference unit 311 is provided in the first embodiment. The vertical imaging unit 91 and the exposure rate detection unit 314 may be omitted. In this case, the height detection unit 315 detects the height hx of the plant ground portion 1A based on the imaging data of the horizontal imaging unit 95, and the reference unit 311 refers to the data table DT and determines the exposure rate according to the height hx. Select Px.

[3. Others]
(1) In each of the above embodiments, the illumination adjustment unit 32 outputs the light irradiation unit 3 so that the irradiation intensity of the light irradiation unit 3 becomes the irradiation intensity setting value ISx determined by the intensity setting units 31 and 31A. However, the illumination adjustment unit 32 may be omitted. In this case, the irradiation intensity setting value ISx is displayed on a monitor or the like, and the operator who confirms this display manually adjusts the output of the light irradiation unit 3 so that the irradiation intensity of the light irradiation unit 3 becomes the irradiation intensity setting value ISx. do it.

  (2) In each said embodiment, while the cultivation by the plant cultivation apparatus 100 was implemented, the determination process of irradiation intensity setting value ISx was performed periodically and repeatedly. On the other hand, the irradiation intensity setting value ISx may be reset only when there is a request from the operator, for example, by pressing a button.

  The amount of light suitable for a plant varies depending on the growth process of the plant. Since the present invention controls the amount of light while monitoring the state of plant growth, the amount of light irradiated to the plant can be set to an optimum value for the growth of the plant, and thus the industrial applicability is great.

1 plant 1A plant above-ground part (cultivation target part)
1B Plant underground part 3 Light irradiation part 4 Ground surface part (planting part)
4A Through-hole 5 Cultivation tank 5A Supply pipe 5B Discharge pipe 6 Top reflector 7 Side reflector 8 Culture solution 11 Tank 12 Pump 21 Ground space (cultivation space)
25 underground space 30, 30A control unit 31, 31A intensity setting unit 32 illumination adjustment unit 35 illumination support unit 41 medium 91 vertical imaging unit (first imaging unit)
92 Vertical imaging unit imaging range 95 Horizontal imaging unit (second imaging unit)
DESCRIPTION OF SYMBOLS 100 Plant cultivation apparatus 200 Housing | casing 311 Reference part 312,312A Memory | storage part 313 Calculation part 314 Exposure rate detection part 315 Height detection part H Distance between the light irradiation part 3 and the ground surface part 4 ha Reference height hx Height Ia Target light amount If Reference light amount La Reference irradiation intensity Pa Reference exposure rate Px Exposure rate Ta Reference time Tx Elapsed time

Claims (7)

A planting part in which plants are planted;
A light irradiator that irradiates light from a first direction to the implanted part; and
An intensity setting unit that increases the set value ISx of the irradiation intensity of the light irradiation unit as the exposure rate Px at which the planting unit is exposed without being covered by the plant when viewed from the first direction is reduced; A plant cultivation device provided. The plant cultivation apparatus according to claim 1, further comprising an illumination adjustment unit that adjusts an output of the light irradiation unit such that an irradiation intensity of the light irradiation unit becomes the set value ISx. The intensity setting unit
The said setting value ISx is made low, so that the height hx of the cultivation object part which is a part of the said plant and is arrange | positioned in the cultivation space between the said light irradiation part and the said planting part becomes high. The plant cultivation apparatus as described. A first imaging unit that images the implanted unit from the first direction;
From a second direction intersecting the first direction, further comprising a second imaging unit that images the cultivation space,
The intensity setting unit
Based on the imaging information of the first imaging unit, an exposed area that is an area of the exposed part that is exposed without the planted part being covered with the plant is obtained, and the exposed area and the first imaging unit The ratio of the imaging area which is the area of the imaging range is acquired as the exposure rate Px,
The plant cultivation apparatus according to claim 3, wherein the height hx is acquired based on imaging information of the second imaging unit. A first imaging unit that images the implanted unit from the first direction;
The intensity setting unit
Storing the correlation between the exposure rate Px and the height hx;
Based on the imaging information of the first imaging unit, an exposed area that is an area of the exposed part that is exposed without the planted part being covered with the plant is obtained, and the exposed area and the first imaging unit The ratio of the imaging area which is the area of the imaging range is acquired as the exposure rate Px,
The plant cultivation apparatus according to claim 3, wherein the height hx is acquired from the exposure rate Px according to the correlation. From the second direction intersecting the first direction, further comprising a second imaging unit that images the cultivation space,
The intensity setting unit
Storing the correlation between the exposure rate Px and the height hx;
Obtaining the height hx based on the imaging information of the second imaging unit;
The plant cultivation device according to claim 3 which acquires said exposure rate Px from said height hx according to said correlation. In addition to the height hx and the exposure rate Px, the intensity setting unit includes a distance H, a reference exposure rate Pa, a reference height ha, a target light amount Ia, a reference irradiation intensity La, and a reference light amount If, which are stored in advance. The plant cultivation apparatus according to any one of claims 3 to 6, wherein the set value ISx is set from the following formula (1) using:

Here, the distance H is a distance between the light irradiation part and the implantation part, the reference exposure rate Pa is the exposure rate Px at a reference time Ta, and the reference height ha is the reference time Ta. The target light amount Ia is the light amount Ix at the reference time Ta and the reference height ha in the cultivation space, and the reference irradiation intensity La is the irradiation intensity at the reference time Ta. The reference light amount If is the light amount Ix at the time when the exposure rate Px becomes zero, and the reference time Ta is from the start of cultivation of the plant until the exposure rate Px becomes zero. It is the point in time selected in time.

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