JP2023040690A - plant cultivation system - Google Patents

Abstract

To make it possible to correctly grasp the actual growth conditions of plants and to reduce the cost and trouble for the measurements.SOLUTION: An air environment measurement device 17 is installed in a semi-closed space 11 in a cultivation room 10 for cultivation of a plant 13, to detect carbon dioxide levels or the like. When measuring carbon dioxide levels or the like necessary for calculation of photosynthesis or transpiration rates, a decrease rate in carbon dioxide levels or the like is observed with the air environment measurement device 17 with the carbon dioxide levels being increased to a target value. On the basis of its result, the photosynthesis or transpiration rates are calculated.SELECTED DRAWING: Figure 1

Description

The present invention relates to a plant cultivation system.

Generally, in a plant factory, light, temperature, humidity and carbon dioxide (CO ₂ ) concentration are controlled in a facility including a completely closed cultivation room and a semi-closed cultivation room, such as a facility in a building. Plants such as vegetables are produced by artificially controlling the internal environment. In addition, such plant factories are roughly classified into a complete artificial light type that uses artificial light from light sources such as LEDs without using sunlight, and a solar type that uses sunlight. In both the full artificial light type and the sunlight type, it is necessary to keep the indoor environment such as temperature and humidity constant, so environmental control is performed using air conditioners and dehumidifiers.

For example, Patent Literature 1 discloses a technique for appropriately homogenizing and maintaining air quality conditions suitable for plant cultivation and contributing to stable quality and increased yield of plants. Specifically, the plant cultivation apparatus of Patent Literature 1 includes a housing, an air recovery pipe, an air conditioner, and an air supply pipe. A housing|casing has the space which cultivates a plant inside. The air recovery pipe is connected to the recovery hole of the housing for recovering the air inside the housing. The air conditioner adjusts the temperature, humidity, and CO ₂ concentration of the air recovered from the recovery holes through the air recovery pipes to conditions suitable for plant cultivation. The air supply pipe connects the air conditioner and the supply hole of the housing, and supplies the air adjusted by the air conditioner into the housing through the supply hole of the housing.

JP 2017-205072 A

For example, by using a technique such as Patent Document 1, it becomes possible to appropriately homogenize air quality conditions in a plant cultivation environment. However, since the actual growth conditions of plants are not constant, it is not always possible to harvest the plants, for example, at an appropriate pre-planned harvest time.

Therefore, there is a demand for a technique for correctly grasping the actual growth conditions of plants.
In an actual plant factory, when various kinds of plants such as vegetables are produced, it is desired to be able to adjust the growth conditions so that each plant can be harvested at the desired harvest time. there is It is also desired to increase the yield of plants and to manage the cultivation of plants so that the profit from their cultivation is maximized.

By the way, for example, there is a large correlation between the state of photosynthesis in plant leaves, the state of transpiration from leaves, and the growth state of plants. There is also a large correlation between the rate of plant photosynthesis and the amount of carbon dioxide absorbed by the plant during photosynthesis. Therefore, if the amount of carbon dioxide actually absorbed by the plant can be correctly grasped, the growth condition of the plant can be grasped.

However, it is very difficult to correctly grasp the amount of carbon dioxide absorbed by plants. For example, even if plants exist in an almost closed space, it is necessary to circulate the air in order to maintain the air environment necessary for the growth of the plants. Concentration of carbon dioxide fluctuates all the time.

Therefore, when measuring the carbon dioxide concentration in the air for the purpose of grasping the amount of carbon dioxide absorbed by plants or the amount of carbon dioxide emitted by plants through respiration, at least two points in the space should be used. It is necessary to measure the carbon dioxide concentration at each and grasp the difference in the carbon dioxide concentration at the two locations.

Therefore, it is necessary to prepare a plurality of measuring instruments and sensors for measuring the carbon dioxide concentration, etc., and install them in different places. In addition, high-precision measuring instruments and sensors used in laboratories are very expensive.

However, when actually operating a plant factory, it is necessary to produce a large number of plants at the lowest equipment cost possible. should be minimized. In particular, when a variety of plants are grown at the same time or when plants with different harvest times are grown in independent environments, a large number of mutually independent cultivation chambers are required. Therefore, if a measuring instrument is individually installed for each cultivation room, a large number of measuring instruments are required for the entire plant factory. In addition, when one or more common measuring instruments are reused for each of a plurality of cultivation rooms, the operator must frequently change the installation position of the measuring instrument manually. increase in operational costs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to provide a plant cultivation system that enables accurate grasping of actual plant growth conditions and that can reduce the cost and labor associated with measurement. That is.

In order to achieve the above object, a plant cultivation system according to the present invention is characterized by the following (1) to (9).
(1) a cultivation chamber capable of forming a semi-enclosed space isolated from the outside air;
a cultivation container that is arranged in the cultivation chamber and that can be used for cultivating plants;
an air environment adjustment unit that forms a substantially closed space with the cultivation room and is capable of adjusting the air environment in the cultivation room;
an environment sensor capable of detecting at least one of carbon dioxide and moisture in the cultivation room or in the vicinity of a portion where air enters and exits the cultivation room;
an evaluation unit that evaluates the cultivation environment of the plant in the cultivation container based on carbon dioxide or moisture detected by the environment sensor;
with
The evaluation unit evaluates the cultivation environment of the plant in the cultivation container based on changes in carbon dioxide or moisture detected by the environment sensor in a state where the air environment in the cultivation room has reached a reference state.
plant cultivation system.

(2) having a correction data holding unit that holds correction data generated in advance based on measurement results of a predetermined reference measuring instrument having higher detection accuracy than the environment sensor;
The evaluation unit evaluates the cultivation environment of the plant in the cultivation container based on the result of correcting the detection value of the environment sensor using the correction data.
The plant cultivation system according to (1) above.

(3) The evaluation unit acquires information on the carbon dioxide concentration in the cultivation room from the output of the environment sensor, and based on the rate of change in the carbon dioxide concentration, the photosynthetic rate of the plants in the cultivation room or the respiration rate in the dark period. evaluate the
The plant cultivation system according to (1) or (2) above.

(4) The evaluation unit acquires information on the moisture content in the air in the cultivation chamber from the output of the environment sensor, and evaluates the transpiration rate of the plants in the cultivation chamber based on the rate of change in the moisture content in the air. do,
The plant cultivation system according to (1) or (2) above.

(5) a connection switching unit capable of switching between connection and non-connection between the cultivation room and the air environment adjustment unit;
a control unit that controls the connection switching unit;
The control unit controls the connection switching unit based on predetermined upper and lower limits, and controls the connection switching unit when the concentration of carbon dioxide in the cultivation chamber rises and reaches the upper limit. to close the air flow path between the cultivation room and the air environment adjustment section, and when the concentration of carbon dioxide in the cultivation room decreases and reaches the lower limit, the connection switching section is controlled to close the cultivation room and the air environment adjustment section. opening an air flow path between the air environment adjustment unit;
The plant cultivation system according to any one of (1) to (4) above.

(6) A cultivation environment adjustment unit that controls the cultivation environment of the plant in the cultivation container;
The cultivation environment adjustment unit reflects the evaluation result of the evaluation unit in adjusting the cultivation environment of the plant in the cultivation container.
The plant cultivation system according to any one of (1) to (5) above.

(7) the cultivation chamber has an air outlet and an air inlet formed in the semi-enclosed space;
The air environment adjustment section includes an air conduit connectable to the air outlet and the air inlet of the cultivation chamber, a temperature and humidity adjustment section that adjusts the temperature and humidity of the air passing through the air conduit, and the a carbon dioxide supply unit that supplies carbon dioxide to the air conduit;
The connection switching unit has two on-off valves arranged near an air outlet of the cultivation room and near an air inlet of the cultivation room, respectively.
The plant cultivation system according to (5) above.

(8) The cultivation environment adjustment unit controls the cultivation environment of the plant in the cultivation container so as to adjust the growth rate of the plant based on the results of evaluating the photosynthesis of the plant.
The plant cultivation system according to (6) above.

(9) comprising a camera for acquiring image data of the plant;
The plant cultivation system according to any one of (1) to (8) above.

According to the plant cultivation system configured in (1) above, it is possible to estimate the photosynthetic rate of the entire plant in the cultivation chamber based on the rate of change in carbon dioxide concentration that can be calculated from the detection value of the environment sensor. Also, for example, the transpiration rate in the leaves of the plant can be estimated based on the humidity change rate that can be calculated from the detection value of the environment sensor. That is, since the environment sensor performs measurement in a state in which the cultivation room and the air environment adjustment unit form a substantially closed space, that is, in a state in which the air in the cultivation room is not exchanged, the influence of plant photosynthesis minutes, or just the effect of plant transpiration can be measured correctly. In this way, measurement can be performed in the space where the plant is actually cultivated, so it is possible to directly grasp the actual growth condition of the plant. Therefore, for example, since it is not necessary to move the plant to a measuring device or the like different from the actual cultivation space each time the measurement is performed, it is possible to reduce the cost and labor involved in the measurement.

According to the plant cultivation system having the configuration (2) above, even when relatively inexpensive general-purpose products are used as the environment sensors, the effects of measurement errors are greatly reduced by correcting the detected values based on the correction data. can. The reference measuring instrument required for generating the correction data is unnecessary during operation of the plant factory. Therefore, even in the case of a plant factory having a large number of cultivation rooms, it is sufficient to prepare only one reference measuring instrument, and a highly accurate and expensive measuring instrument can be used.

According to the plant cultivation system having the configuration (3) above, since the photosynthetic rate of the plants in the cultivation chamber is evaluated, it is possible to correctly estimate the growth status of the plants. This makes it possible to increase the yield of plants in the plant factory and to control the environment of the plant factory for adjusting the harvest time for each cultivation room.

According to the plant cultivation system having the configuration (4) above, since the transpiration rate of the plant in the cultivation chamber is evaluated, it is possible to correctly estimate the growing state of the plant. As a result, the growth of plants in the plant factory can be advanced or delayed, so that the plant factory can be controlled for each cultivation room to adjust the harvest time.

According to the plant cultivation system having the configuration (5) above, it becomes easy to control the concentration of carbon dioxide in the cultivation chamber so as to be maintained within the range of the upper limit and the lower limit. As a result, it is possible to avoid large fluctuations in the environment for growing plants in the cultivation chamber. In addition, when the air flow path between the cultivation room and the air environment adjustment unit is closed, information on the rate of change in carbon dioxide concentration necessary for evaluating plant photosynthesis is obtained from changes in the measured values of the environment sensor. become available.

According to the plant cultivation system having the configuration of (6) above, since the evaluation result of the evaluation unit is reflected in the adjustment of the cultivation environment for the plants in the cultivation container, the actual growth status of the plants can be adjusted according to the target cultivation schedule. It becomes possible to adjust the environment so that it approaches. This makes it easier to increase the yield of plants and adjust the harvest time for each cultivation room.

According to the plant cultivation system having the configuration of (7) above, when the two on-off valves are open, an air flow is created in the semi-closed space of the cultivation chamber from the air inlet toward the air outlet, It is possible to create and circulate an air flow from the air outlet side of the cultivation chamber to the air inlet side in the air duct. In addition, it is possible to adjust the temperature and humidity of the circulating air, and to replenish carbon dioxide that has been consumed and reduced in the photosynthesis of plants, so that an air environment suitable for plant cultivation can be maintained. By temporarily closing the two on-off valves, changes in the amount of carbon dioxide and the amount of water in the air in the cultivation room can be accurately measured.

According to the plant cultivation system having the configuration of (8) above, feedback control can automatically equalize the growing state of the plants. Therefore, manual operations for appropriately adjusting temperature, humidity, carbon dioxide concentration, oxygen concentration, etc. are eliminated or reduced during the operation of the plant factory, and personnel costs are reduced.

According to the plant cultivation system having the configuration (9) above, the growth state of the plant can be directly grasped from the image data acquired by the camera. Thereby, for example, cultivation can be performed while monitoring both the photosynthetic rate and the actual growth state, and the growth can be controlled by adjusting the environment.

According to the plant cultivation system of the present invention, it is possible to correctly grasp the actual growth conditions of plants. Moreover, when the plant factory is operated, the measurement can be performed in the space where the plants are actually cultivated, so that the cost and labor involved in the measurement can be reduced.

The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by reading the detailed description below with reference to the accompanying drawings.

FIG. 1 is a vertical cross-sectional view showing a configuration example of a plant cultivation system according to an embodiment of the present invention. FIG. 2 is a flow chart showing main controls in the plant cultivation system of FIG. FIG. 3 is a time chart showing changes over time in the state of the on-off valve and the concentration of carbon dioxide. FIG. 4 is a flow chart showing the procedure of calibration processing. FIG. 5 is a block diagram showing a control system of a plant factory including multiple cultivation chambers. FIG. 6(a), FIG. 6(b), and FIG. 6(c) are graphs each showing an example of transition of carbon dioxide concentration in the cultivation room. FIGS. 7(a), 7(b), and 7(c) show examples of changes in photosynthetic rate measured using a reference measuring instrument while the carbon dioxide concentration in the cultivation room is controlled to a constant value. It is a graph showing. FIGS. 8(a) and 8(b) are graphs showing correlations between measurement results of a general measuring device and a reference measuring device, respectively, regarding photosynthetic rate and transpiration rate. FIG. 9 is a time chart showing an example of concentration transition when the carbon dioxide concentration in the cultivation room is controlled to be constant.

Specific embodiments of the present invention will be described below with reference to each drawing.
<System configuration>
FIG. 1 shows a basic configuration example of a plant cultivation system 50 according to an embodiment of the present invention. That is, FIG. 1 shows an outline of the internal structure of the main part of the plant cultivation system included in the plant factory.

The plant cultivation system 50 shown in FIG. 1 includes one cultivation chamber 10 necessary for cultivating plants 13 . This cultivation room 10 has a semi-enclosed space 11 formed inside a box-shaped housing. That is, the box-shaped housing is made of a material that has heat insulation and light shielding properties, and also has a certain degree of airtightness and watertightness (for example, resin such as urethane foam, fiber-based heat insulating material such as glass wool, rock wool, etc.). A semi-enclosed space 11 surrounded by a plurality of walls, a bottom, a ceiling, and the like is formed. In order to efficiently irradiate the plants 13 with the generated light inside the cultivation chamber 10, each part of the inner wall of the box-shaped housing is made of a material having a high light reflectance.

Therefore, the semi-enclosed space 11 inside the box-shaped housing is isolated from the outside air, and the air environment of the cultivation room 10, that is, the conditions such as carbon dioxide concentration, oxygen concentration, temperature, humidity, etc., are different from the outside air. there is

As shown in FIG. 1, a cultivation container 12 capable of cultivating a plurality of plants 13 is installed near the bottom of the cultivation chamber 10 . The cultivation container 12 forms a pool capable of accommodating a nutrient solution 14 necessary for hydroponically growing plants 13, and has a plate-like tray on which a plurality of plants 13 can be arranged side by side. . A camera 18 for acquiring image data of the plant 13 is installed in the cultivation room 10, for example, near the ceiling. The growth state of the plant 13 can be directly grasped from the image data acquired by the camera 18 .

A lighting device 15 is installed near the ceiling in the cultivation room 10 in order to irradiate the light necessary for growing the plants 13 . Note that the installation position of the lighting device 15 is not limited to the vicinity of the ceiling. Also, any existing device such as a device using an LED light source can be used as the lighting device 15 . Alternatively, for example, an LED light source may be installed outside the cultivation room 10 and the light emitted from this LED light source may be irradiated to the plant 13 through a light guide plate provided inside the cultivation room 10 .

In order to enable adjustment of the air environment in the cultivation room 10, an air inlet 10a is formed on one wall surface of the cultivation room 10, and an air outlet 10b is formed on the opposite wall surface. A conduit outlet 20b of the air conduit 20 is connected to the air inlet 10a, and a conduit inlet 20a of the air conduit 20 is connected to the air outlet 10b.

As an example, the air conduit 20 is configured by a pipe having airtightness and a substantially constant cross-sectional area, and forms an air flow path for circulating the air inside the cultivation room 10 outside thereof. That is, the air in the cultivation room 10 enters the air conduit 20 from the air outlet 10b via the conduit inlet 20a, passes through the flow path in the air conduit 20, reaches the conduit outlet 20b, and passes through the air inlet 10a. It is introduced again into the cultivation room 10 via the.

An air conditioner 23 is connected in the middle of the flow path of the air pipe 20 . Also, although not shown, an air pump or fan is arranged on the air conduit 20 as needed. The air duct 20 can form an air flow in the direction from the duct outlet 20b toward the inside of the cultivation chamber 10 . The air conditioning unit 23 has a dehumidification/humidification function and a temperature control function for the air passing through the air conduit 20 .

A cylinder 24 is also connected to the air pipeline 20 via a supply pipeline 25 . The cylinder 24 can supply carbon dioxide (CO ₂ ) accumulated therein to the supply line 25 as needed. Carbon dioxide passing through replenishment line 25 replenishes the air in air line 20 at replenishment point 25a. Therefore, the concentration of carbon dioxide in the air can be increased within the air conduit 20 as needed.

Each cylinder 24 is equipped with an electromagnetic valve for controlling the on/off of the supply of carbon dioxide or the amount of supply. This electromagnetic valve is controlled by the controller 40, for example. In addition to the cylinder 24 , a cylinder (not shown) that supplies oxygen (O ₂ ) may be connected to the supply line 25 in some cases.

The air pipeline 20, the air conditioning unit 23, the cylinder 24, and the supply pipeline 25 form a substantially closed space with the cultivation room 10, and constitute an air environment adjustment unit capable of adjusting the air environment in the cultivation room 10. do.

As shown in FIG. 1, an on-off valve 21 is connected near the pipeline inlet 20a, and an on-off valve 22 is connected near the pipeline outlet 20b. The opening/closing valves 21 and 22 are controlled to be opened/closed by control signals SG1 and SG2 output from the controller 40, respectively.

Normally, the on-off valves 21 and 22 are open. As a result, the air in the semi-enclosed space 11 circulates through the air conduit 20, and the temperature, humidity, carbon dioxide concentration, etc. can be maintained within appropriate ranges.

For example, since carbon dioxide is consumed by photosynthesis of the plants 13, the concentration of carbon dioxide in the air within the semi-enclosed space 11 gradually decreases. At the same time, the humidity in the air in the semi-enclosed space 11 increases as the plants 13 transpire. By circulating air using the air duct 20, changes in carbon dioxide concentration and humidity in the semi-enclosed space 11 can be suppressed, and an environment suitable for the growth of the plants 13 can be formed.

A plurality of blowers 16 are installed inside the semi-enclosed space 11 . These blowers 16 can be used to create a suitable air flow and to homogenize the air environment within the semi-enclosed space 11 .

In this embodiment, in order to measure information that can be used for estimating the actual photosynthetic rate and transpiration rate of the plant 13, the on-off valves 21 and 22 are temporarily closed as described later. As a result, the semi-enclosed space 11 is closed. On the other hand, when the on-off valves 21 and 22 are open, the inside of the semi-closed space 11 and the air environment adjustment section form a substantially closed space. In this state, the supply of carbon dioxide from the cylinder 24 is stopped, and air is circulated through the air pipe 20, the air conditioning unit 23, and the cultivation room 10, thereby enabling measurement by the air environment measuring device 17, which will be described later.

In the configuration shown in FIG. 1, an air environment measuring device 17 is installed near the air outlet 10b in the semi-enclosed space 11. As shown in FIG. This air environment measuring device 17 is a relatively inexpensive general-purpose measuring device that can be used on a daily basis in plant factories. In addition, this air environment measuring instrument 17 has a function of measuring carbon dioxide concentration, temperature and humidity. For example, T&D's T&D (registered trademark) (RTR576) can be used as the air environment measuring instrument 17 .

The air environment measuring instrument 17 can transmit the measurement result information i17 to the control unit 40 by wireless communication, for example. The measurement result information i17 includes information on the carbon dioxide concentration, temperature, and humidity obtained by measurement by the air environment measuring instrument 17. FIG.

In addition, in the plant cultivation system 50 shown in FIG. 1, one air environment measuring device 17 is installed in the semi-enclosed space 11, but depending on the size of the cultivation room 10, a plurality of air environment measuring devices 17 may be installed. It is preferable to set them separately and average the numerical values.

In the example shown in FIG. 1, in a normal cultivation state, an air flow can be formed in the cultivation chamber 10 in the direction from the air inlet 10a to the air outlet 10b. In particular, the height from the bottom to the ceiling is relatively small compared to the width (horizontal dimension in FIG. 1) and depth (vertical dimension in FIG. 1) of the cultivation chamber 10, A stable horizontal air flow can be formed in the cultivation room 10 .

When cultivating the plant 13, carbon dioxide ( _6CO2 ) and water ( _12H2O ) are absorbed with photosynthesis by _{the plant} 13, and glucose ( _C6H12O6 ), oxygen ( _6O2 ), and Moisture (6H ₂ O) is discharged. Therefore, if changes in the concentration of carbon dioxide in the air and changes in the amount of water discharged by transpiration can be correctly grasped, photosynthesis can be evaluated based on this, and the actual growth state of the plant 13 can be estimated. In addition, it is possible to evaluate the respiration rate of the plant 13 by grasping the change in the concentration of carbon dioxide in the air during the dark period. In the present disclosure, the term "dark period" refers to a period in which the light applied to the plants is insufficient and little photosynthesis occurs in the plants, and means, for example, a period in which the lighting device 15 is turned off.

In the plant cultivation system 50 shown in FIG. 1, the control unit 40 maintains the carbon dioxide concentration, oxygen concentration, temperature, humidity, etc., which are the air environment in the semi-enclosed space 11, at target values suitable for the growth of the plants 13. It has a control function for In addition, the control unit 40 grasps the carbon dioxide concentration and humidity from the measurement result information i17 obtained by the measurement of the air environment measuring device 17, estimates the photosynthesis rate, respiration rate and transpiration rate, and the result is reflected in the control of the cultivation environment of the plant 13. Hereinafter, the photosynthetic rate, respiration rate and transpiration rate may be referred to as photosynthetic rate and the like.

Further, when measuring the measurement result information i17 necessary for estimating the photosynthetic rate and the like, the control unit 40 controls the opening and closing of the on-off valves 21 and 22 using the control signals SG1 and SG2 as will be described later. As a result, the control unit 40 can accurately estimate the photosynthetic rate and the like simply by using a single relatively inexpensive air environment measuring device 17 .

As shown in FIG. 1 , a nutrient solution tank 33 is installed adjacent to the cultivation room 10 . The nutrient solution supply pipe 31 has one end connected to the nutrient solution tank 33 and the other end connected to the cultivation container 12 via the nutrient solution inlet of the cultivation room 10 . One end of the nutrient solution discharge pipe 32 is connected to the cultivation container 12 via the nutrient solution outlet of the cultivation chamber 10 , and the other end is connected to the nutrient solution tank 33 .

A fertilizer supply source 34 is connected to a fertilizer supply section 35, and the fertilizer supply section 35 is connected to the nutrient solution tank 33 via a fertilizer supply pipe. The fertilizer supply unit 35 can take in fertilizer necessary for promoting the growth of the plants 13 in the cultivation chamber 10 from the fertilizer supply source 34 and supply the fertilizer to the nutrient solution tank 33 as necessary. Then, for example, the pH (hydrogen ion concentration index) and EC (electrical conductivity) of the nutrient solution 14 in the nutrient solution tank 33 are controlled to be target values. A pH measuring device 36 is installed in the nutrient solution tank 33 to measure pH and EC.

The nutrient solution 14 in the nutrient solution tank 33 is supplied to the inside of the cultivation container 12 in a required amount through the nutrient solution supply pipe 31 by driving the pump 37 . Also, the nutrient solution 14 discharged from the downstream side of the cultivation container 12 is collected in the nutrient solution tank 33 via the nutrient solution discharge pipe 32 .

The seedlings of each plant 13 placed on the cultivation container 12 are supported with their roots immersed in the nutrient solution 14 in the cultivation container 12. It can grow by absorbing nutrients and water. During the evaluation of the photosynthetic rate, the circulation of the nutrient solution may be in operation or may be stopped.

<Main control>
A specific example of main controls in the plant cultivation system 50 of FIG. 1 is shown in FIG. That is, the control unit 40 shown in FIG. 1 performs the control shown in FIG. Further, when performing the control of FIG. 2, the control unit 40 uses the correction data storage unit TB1 that holds correction data determined in advance. This correction data is generated as a result of calibration processing, which will be described later. The control of FIG. 2 will be described below.

The control unit 40 controls the control signals SG1 and SG2 in the first step S11 to switch the on-off valves 21 and 22 to the open state. As a result, the air in the semi-enclosed space 11 circulates through the air conduit 20 .

Since carbon dioxide is consumed by the photosynthesis of the plants 13 in the semi-enclosed space 11, the concentration of carbon dioxide in the air will gradually decrease if nothing is done. In addition, the humidity in the air increases as the plants 13 transpire. However, when air is circulated through the air pipe 20, carbon dioxide is replenished from the cylinder 24, so that the concentration of carbon dioxide in the air can be gradually increased. Also, the humidity of the circulating air can be lowered by using the dehumidifying function of the air conditioning unit 23 .

On the other hand, the air environment measuring device 17 placed in the semi-enclosed space 11 repeatedly measures carbon dioxide concentration, temperature, and humidity, and periodically and repeatedly transmits measurement result information i17 indicating the measurement results by wireless communication. do.

The control unit 40 acquires the measurement result information i17 obtained by the measurement by the air environment measuring device 17 in step S12. Then, the control unit 40 compares the latest carbon dioxide concentration obtained by the measurement of the air environment measuring device 17 with a predetermined upper limit value VU (for example, 1000 [ppm]) (S13).

When the detected carbon dioxide concentration reaches or exceeds the upper limit value VU, the control unit 40 proceeds to processing from step S13 to step S14, controls the control signals SG1 and SG2, and switches the on-off valves 21 and 22 to the closed state.

As a result, the semi-enclosed space 11 is isolated from the air conduit 20, and air circulation is temporarily stopped. Further, when the air circulation stops, the concentration of carbon dioxide in the air inside the semi-enclosed space 11 gradually decreases as the plants 13 perform photosynthesis. At the same time, the humidity in the air gradually increases with transpiration.

The control unit 40 acquires the measurement result information i17 obtained by the measurement by the air environment measuring device 17 in step S15. Then, the control unit 40 repeatedly observes the latest changes in the carbon dioxide concentration and humidity obtained by the measurement by the air environment measuring device 17 (S16).

The control unit 40 estimates the photosynthetic rate of the plant 13 based on the rate of decrease in carbon dioxide concentration detected in step S16 (S17). At the same time, the transpiration rate of the plant 13 is also estimated based on the humidity increase rate detected in step S16. Also, in order to enable more accurate estimation, the control unit 40 corrects each estimated value using the correction data held in the correction data storage unit TB1.

The control unit 40 reflects the estimated value of the photosynthetic rate and the estimated value of the transpiration rate calculated in step S17 in the environmental control of the plant factory in the next step S18. For example, if the actual plant growth is slower than the planned plant growth situation, it is thought that the photosynthetic rate and the transpiration rate tend to be lower than planned, so plant growth should be promoted. For this reason, adjustments such as raising the standard value (control target value) for carbon dioxide concentration are performed automatically or manually. In addition, if the actual plant growth is too fast compared to the planned plant growth situation, it is thought that the photosynthesis rate and the transpiration rate tend to be higher than the plan. automatic adjustment such as lowering the standard value of carbon dioxide concentration. This enables uniform plant growth and the like.

The control unit 40 compares the latest carbon dioxide concentration acquired in step S15 with a predetermined lower limit value VL (eg, 300 [ppm]) (S19). Then, when the detected carbon dioxide concentration becomes equal to or lower than the lower limit value VL, the control unit 40 proceeds to processing from step S19 to step S20, controls the control signals SG1 and SG2, and opens the on-off valves 21 and 22, respectively. As a result, air circulation is restarted, so the concentration of carbon dioxide in the air gradually increases and the humidity gradually decreases.

Note that the control shown in FIG. 2 is performed by the control unit 40 as necessary at the time when it is necessary to grasp the actual growth state of the plant 13 . When the control shown in FIG. 2 is not performed, the concentration of carbon dioxide in the air in the semi-enclosed space 11 is controlled by the controller 40 so as to approach a predetermined target value.

<Example of state change during control>
FIG. 3 shows an example of the state of the on-off valves 21 and 22 and the change over time of the carbon dioxide concentration when the control of FIG. 2 is carried out.

When carrying out the control of FIG. 2, the concentration of carbon dioxide in the air is increased and the descent is alternately repeated.

That is, the carbon dioxide concentration continues to rise while the on-off valves 21 and 22 are open, and the carbon dioxide concentration continues to drop when the on-off valves 21 and 22 are closed.
In the control of FIG. 2, at each measurement interval Tm shown in FIG. to estimate

That is, when the on-off valves 21 and 22 are closed, the amount of air in the semi-enclosed space 11 is constant and no replacement occurs. leads to a decrease in carbon dioxide concentration. Therefore, the control unit 40 can estimate the photosynthetic rate based on the carbon dioxide concentration decreasing rate obtained by the measurement. Similarly, the controller 40 can estimate the respiration rate based on the rate of increase in carbon dioxide concentration obtained by measurement during the dark period.

Also, the control unit 40 estimates the transpiration rate based on the change in humidity in the measurement section Tm. Since there is a large correlation between the photosynthetic rate, respiration rate and transpiration rate of plants, only one of the photosynthesis rate, respiration rate and transpiration rate can be grasped when managing plants in a plant factory. But it can be managed properly.

<Calibration process>
FIG. 4 shows a procedure of calibration processing performed to generate correction data in the correction data storage unit TB1 used by the control unit 40 of the plant cultivation system 50. As shown in FIG.

In the plant cultivation system 50 shown in FIG. 1, only one relatively inexpensive air environment measuring device 17 is installed in the semi-enclosed space 11 to measure the carbon dioxide concentration, etc. Therefore, the air environment measuring device 17 If the measurement results are used as they are, the error may become large and the estimation accuracy of the photosynthetic rate may decrease. Therefore, in the present embodiment, a reference measuring instrument having higher detection accuracy than the air environment measuring instrument 17 is prepared, and calibration processing necessary for reducing measurement errors of the air environment measuring instrument 17 is performed. The procedure of the calibration process is shown in FIG.

As the reference measuring instrument to be prepared, for example, "Plant Photosynthesis Comprehensive Analysis System" LI-6800 manufactured by Meiwa Forsys Co., Ltd. can be used. Since this reference measuring instrument is expensive, it is difficult to use it at all times in a plant factory.

The calibration process shown in FIG. 4 will be described below.
In step S31, in an environment equivalent to the plant cultivation system 50 shown in FIG. 1, for example, the control unit 40 opens the on-off valves 21 and 22 to raise the carbon dioxide concentration in the cultivation room 10 to the target value. A target value is, for example, 1000 [ppm].

When the carbon dioxide concentration in the cultivation room 10 reaches the target value, for example, the controller 40 closes the on-off valves 21 and 22 to stop supplying carbon dioxide to the semi-closed space 11 (S32).

In step S33, the time transition of the carbon dioxide concentration measured by the air environment measuring device 17 is monitored by, for example, the control unit 40, and the time-series data is acquired and recorded.

Next, a reference measuring device (not shown) is prepared, and the operator installs the detection unit of this reference measuring device in the cultivation room 10 (S34). Specifically, one of the two sensor units of the reference measuring instrument is arranged near the air inlet 10a or the conduit outlet 20b (in side), and the other is arranged near the air outlet 10b or the conduit inlet 20a (out side). to be placed. As a result, the air in the in-side channel and the air in the out-side channel can be measured. The photosynthetic velocity Vps in this case can be calculated from the following equation based on the detection state of the reference measuring instrument.

Vps=Vaf*RCO2*Rh (1)
Vps: Photosynthetic rate [μmol/m ² /s]
RCO2 = (VCO2in - VCO2out)
Rh = VH2Oin/VH2Oout
Vaf: air volume in flow path RCO2: carbon dioxide absorption ratio Rh: humidity change ratio VCO2in: in-side carbon dioxide concentration VCO2out: out-side carbon dioxide concentration VH2Oin: in-side humidity VH2Oout: out-side humidity

The reference instrument outputs the photosynthetic rate Vps and the transpiration rate as measurements.
In step S35 of FIG. 4, for example, the control unit 40 opens the on-off valves 21 and 22 to raise the carbon dioxide concentration in the cultivation room 10 to the target value, and maintains that state. Here, the target value is assumed to be 1000 [ppm], for example.

In steps S36 and S37, measurements of the photosynthetic rate and the like are repeated with the reference measuring instrument, and the controller 40 or the operator monitors until the measured values are sufficiently stabilized.
When the measured value of the reference measuring instrument is stabilized, the data of the measured value of the reference measuring instrument, that is, the photosynthetic rate, respiration rate and transpiration rate are recorded in the next step S38.

In the next step S39, the photosynthetic rate and the like of the reference measuring instrument obtained in S38 are compared with the measurement data of the air environment measuring instrument 17 obtained in step S33. However, before the comparison, it is necessary to perform conversion to align the units of both data. In addition, when calculating the transpiration rate in the semi-enclosed space 11, it is necessary to grasp the amount of change in absolute humidity. Relative humidity/absolute humidity interconversion must be performed when comparing the measurement data of the device 17 .

Further, in step S39, correcting the photosynthetic rate of the reference measuring instrument and the like, correction data required to reduce errors in the measurement data of the air environment measuring instrument 17 are generated by calculation. Then, the generated correction data is stored in the correction data storage unit TB1.

<Control system of plant factory>
FIG. 5 shows a configuration example of the control system of the plant factory 100 including a plurality of cultivation chambers.
In the configuration shown in FIG. 5, a plant factory 100 is provided with four cultivation chambers 10A, 10B, 10C, and 10D each having a semi-enclosed space 11 independent of each other. These cultivation rooms 10A to 10D each have an independent control system equivalent to the plant cultivation system 50 shown in FIG.

The data management unit 61 sequentially acquires data output from each of the operating cultivation rooms 10A to 10D, and accumulates the acquired data in the data accumulation unit 62 while distinguishing the data for each cultivation room. This data includes information such as the temperature, humidity, and carbon dioxide concentration included in the measurement result information i17 of each cultivation room, the date and time, and the open/closed states of the on-off valves 21 and 22 .

The photosynthesis evaluation unit 63 acquires the data accumulated by the data accumulation unit 62 and individually evaluates photosynthesis for each cultivation room in order to grasp the actual growth status of the plants 13 . That is, the photosynthesis evaluation unit 63 calculates the photosynthesis rate based on the change rate of the carbon dioxide concentration for each measurement interval Tm shown in FIG. The photosynthesis evaluation unit 63 also calculates the transpiration rate based on the humidity change rate for each measurement section Tm. In addition, the photosynthesis evaluation unit 63 identifies the dark period based on the date and time information, and calculates the respiration rate based on the change rate of the carbon dioxide concentration for each measurement interval in which the on-off valves 21 and 22 are closed during the dark period. .

The photosynthesis evaluation unit 63 feeds back the evaluation result for each cultivation room, that is, data such as the calculated photosynthesis rate to the input of the cultivation environment determination unit 64 .

The cultivation environment determination unit 64 compares, for example, a predetermined cultivation recipe for each plant variety with the photosynthesis rate and the like fed back from the photosynthesis evaluation unit 63, and estimates the actual plant growth situation for each cultivation room. . In addition, the cultivation environment determination unit 64 compares the estimated actual plant growth status with the cultivation schedule of the plants 13 for each cultivation room in the plant factory 100, and adjusts the cultivation environment for each cultivation room.

For example, when the actual growth of the plants 13 is delayed compared to the cultivation schedule of the plants 13 in the cultivation room 10A, in the environmental condition (A) given to the cultivation room 10A by the cultivation environment determination unit 64, the semi-closed space 11 is instructed to increase the control target value of the carbon dioxide concentration. Alternatively, the cultivation environment determination unit 64 instructs the lighting device 15 to increase the lighting time or increase the amount of light with which the plant 13 is irradiated.

In addition, when the actual growth of the plants 13 is too early compared to the cultivation schedule of the plants 13 in the cultivation room 10B, the semi-closed space 11 Instruct to lower the control target value of carbon dioxide concentration inside.
Alternatively, an instruction is given to shorten the time during which the lighting device 15 is lit during the day, or to reduce the amount of light that the lighting device 15 irradiates the plant 13 with.

Control by the cultivation environment determination unit 64 as described above makes it easier to equalize the actual growth conditions of the plants 13 in the plant factory 100 and cultivate the plants 13 in accordance with the cultivation schedule.

<Description of the grounds for control content>
- <Transition of carbon dioxide concentration>
Examples of changes in carbon dioxide concentration in the cultivation room 10 are shown in FIGS.

That is, from the state in which the carbon dioxide concentration in the cultivation room 10 is maintained at a predetermined target value, the time-series change in the carbon dioxide concentration after the on-off valves 21 and 22 are closed, the air arranged in the cultivation room 10 The results measured by the environment measuring device 17 are shown in FIGS. 6(a) to 6(c). Moreover, this measurement was repeated three times. Three measurements are shown in each graph.

The measurement result of FIG. 6A is the result of measurement under the condition that the target value of carbon dioxide concentration is 1000 [ppm]. The measurement results of FIGS. 6B and 6C are the results obtained under conditions where the target values of the carbon dioxide concentration are 1500 and 2000 [ppm], respectively.

That is, since the total amount of carbon dioxide in the cultivation room 10 after the on-off valves 21 and 22 are closed is constant, the amount of carbon dioxide consumed by the photosynthesis of the plants 13 in the cultivation room 10 is the same as the decrease in the carbon dioxide concentration. reflected.

From the measurement results of FIGS. 6(a) to 6(c), it can be seen that the carbon dioxide concentration in the cultivation room 10 tends to decrease gradually and stably over time. Also, the change can be measured by the air environment measuring device 17 . In other words, it is considered that the rate of decrease in carbon dioxide concentration measured by the air environment measuring device 17 in the cultivation room 10 when the on-off valves 21 and 22 are closed reflects the photosynthetic rate in the plants 13 in the cultivation room 10. be done.

－<Transition of photosynthetic rate>
7(a), 7(b) and FIG. 7(c).

The measurement result of FIG. 7A is the result of measurement under the condition that the target value of carbon dioxide concentration is 1000 [ppm]. The measurement results of FIGS. 7B and 7C are the results obtained under conditions where the target values of the carbon dioxide concentration are 1500 and 2000 [ppm], respectively.

From the measurement results of FIGS. 7(a) to 7(c), when measuring the photosynthetic rate in the cultivation room 10 with the reference measuring instrument, after about 20 minutes have elapsed from the start of measurement, It can be seen that photosynthesis can be measured in a stable reaction state.

Therefore, in the calibration process shown in FIG. 4, for example, it is considered that the time required for the measurement value of the reference measuring device to stabilize in step S37 will be about 20 minutes.

- <Correlation of measurement results>
Correlations between the photosynthetic rate and the transpiration rate calculated based on the measurement results of the air environment measuring instrument 17 and the reference measuring instrument are shown in FIGS. 8(a) and 8(b).

In FIG. 8(a), the vertical axis indicates the photosynthetic rate [μmol/kg/s] measured by the reference measuring device (LI6800), and the horizontal axis indicates the measurement result of the air environment measuring device 17 and the measurement result of the reference measuring device. The photosynthetic rate is shown as a result of conversion for comparison. The graph of FIG. 8(a) includes the results of measurement under three different conditions of target values of carbon dioxide concentration of 1000, 1500, and 2000 [ppm].

In FIG. 8(b), the vertical axis indicates the transpiration rate [μmol/kg/s] measured by the reference measuring device (LI6800), and the horizontal axis indicates the measurement result of the air environment measuring device 17 and the measurement result of the reference measuring device. It shows the transpiration rate as a result of conversion for comparison. The graph of FIG. 8B includes the results of measurement under three different conditions of target values of carbon dioxide concentration of 1000, 1500, and 2000 [ppm].

From the contents of the graph shown in FIG. 8(a), the photosynthetic rate obtained from the measured values of the reference measuring instrument and the air environment measuring instrument 17 has a nearly linear correlation with changes in the carbon dioxide concentration. It is clear that

Further, from the contents of the graph shown in FIG. 8(b), the transpiration rate obtained from the measurement values of the reference measuring device and the air environment measuring device 17 has a nearly linear correlation with the change in carbon dioxide concentration. It is clear that we have

In addition, it is considered that the characteristics of the reference measuring device and the characteristics of the air environment measuring device 17 do not change significantly if the conditions are stable, such as after a certain period of time has elapsed from the start of measurement. Therefore, if the measurement result of the air environment measuring device 17 is corrected using a predetermined correction coefficient so that the measurement result of the air environment measuring device 17 approaches the measurement result of the reference measuring device, the measurement result of the air environment measuring device 17 Highly accurate photosynthetic rate and the like can be obtained based only on

Such correction coefficients can be obtained in advance by the calibration process shown in FIG. 4, and can be registered in the correction data storage unit TB1. Therefore, when the control shown in FIG. 2 is performed, the photosynthetic rate and the like can be grasped with high accuracy based on the measurement results of the air environment measuring device 17 installed in each cultivation room 10 . In addition, by feeding back the obtained photosynthetic rate and the like to the control of the plant factory, efficient plant cultivation becomes possible. For example, it becomes easy to adjust the air environment in the semi-enclosed space 11 so as to equalize the growing conditions of the plants to match the cultivation schedule, and to promote the growth of the plants in order to increase the yield.

<Example of changes in carbon dioxide concentration>
FIG. 9 shows an example of concentration transition when the carbon dioxide concentration in the cultivation room is controlled to be constant.

In a normal plant factory, it is not necessary to constantly measure photosynthetic rate and transpiration rate. Therefore, in a daily cultivation environment, the control unit 40 performs control so that the carbon dioxide concentration in the cultivation room 10 shown in FIG. 1 becomes a constant target value (set value), for example, 1000 [ppm].

For example, when the concentration of carbon dioxide detected by the air environment measuring device 17 exceeds a set value, the control unit 40 closes the on-off valves 21 and 22 or closes the supply line 25 from the cylinder 24 to stop the supply of carbon dioxide. Stop. Further, when the carbon dioxide concentration detected by the air environment measuring device 17 becomes less than the set value, the control unit 40 opens the on-off valves 21 and 22 or opens the supply line 25 from the cylinder 24 to supply carbon dioxide. resume.

When the control unit 40 performs the control as described above, the actual carbon dioxide concentration in the cultivation room 10 is maintained in a stable state close to the set value as shown in FIG. Therefore, the plant 13 in the cultivation room 10 can be cultivated in a stable air environment.

In the plant cultivation system 50 shown in FIG. 1, the air environment measuring device 17 is installed at a position close to the air outlet 10b of the cultivation room 10, but the air environment measuring device 17 may be installed at another location. Also good. Further, the positions of the pipeline inlet 20a and the pipeline outlet 20b of the air pipeline 20 connected to the cultivation room 10 may be changed to other positions. For example, the pipeline inlet 20a and the pipeline outlet 20b may be connected to the wall surface on the same side in the cultivation room 10 .

<Advantages of Plant Cultivation System>
In the plant cultivation system 50 shown in FIG. 1, the photosynthetic rate and the like in the environment where the plants 13 are actually cultivated can be grasped simply by using the measurement results of the air environment measuring device 17 installed in the cultivation room 10. . Moreover, in the plant cultivation system 50, the accuracy of estimating the photosynthetic rate and the like can be greatly improved by correcting the measurement result using the correction data stored in the correction data storage unit TB1 obtained by the calibration process performed in advance. can.

Therefore, for example, even in the case of simultaneously cultivating various varieties or a plurality of groups of plants with different shipping times in a plant factory having a large number of mutually independent cultivation chambers, the equipment cost does not increase significantly, and the actual production It becomes possible to grasp the growth status of plants for each cultivation room. In addition, since work such as changing the installation location of the air environment measuring device 17 is not required, it is possible to avoid an increase in personnel costs associated with the work.

<Measurement with air leakage>
As described above, in the plant cultivation system 50 shown in FIG. 1, the carbon dioxide concentration and humidity in the semi-enclosed space 11, which is a substantially closed space, are measured in the environment where the plant 13 is actually cultivated. . However, in reality, there is movement of air inside and outside the semi-enclosed space 11, that is, air leakage. Therefore, it is preferable to perform the measurement in consideration of air leakage. Specifically, the amount of leaked air when the inside of the semi-enclosed space is air-conditioned without the plant 13 is measured in advance and stored in the control unit 40 . Then, the control unit 40 evaluates the photosynthetic rate and the like with a value obtained by subtracting this air leakage amount from the measurement result information i17 obtained by the measurement of the air environment measuring device 17 .

<Supplementary explanation>
Here, the features of the embodiment of the plant cultivation system according to the present invention described above are summarized and listed briefly in [1] to [9] below.
[1] a cultivation chamber (10) capable of forming a semi-enclosed space isolated from the outside air;
a cultivation container (12) that is arranged in the cultivation chamber and that can be used for cultivating plants;
an air environment adjustment unit (air conduit 20) that forms a substantially closed space with the cultivation room and is capable of adjusting the air environment in the cultivation room;
an environment sensor (air environment measuring device 17) capable of detecting at least one of carbon dioxide and moisture in the cultivation room or in the vicinity of a portion where air enters and exits the cultivation room;
an evaluation unit (control unit 40, S17) that evaluates the cultivation environment of the plant in the cultivation container based on the carbon dioxide or moisture detected by the environment sensor;
with
The evaluation unit evaluates the cultivation environment of the plant in the cultivation container based on the change in carbon dioxide or moisture detected by the environment sensor (S16) in a state where the air environment in the cultivation room reaches a reference state. (S17),
A plant cultivation system (50).

[2] having a correction data holding unit (correction data storage unit TB1) that holds correction data generated in advance based on the measurement results of a predetermined reference measuring instrument that has higher detection accuracy than the environment sensor;
The evaluation unit evaluates the cultivation environment of the plant in the cultivation container based on the result of correcting the detection value of the environment sensor using the correction data (S17);
The plant cultivation system according to [1] above.

[3] The evaluation unit acquires information on the carbon dioxide concentration in the cultivation room from the output of the environment sensor, and based on the rate of change in the carbon dioxide concentration, the photosynthetic rate or the respiration rate in the dark period of the plants in the cultivation room. (S17),
The plant cultivation system according to the above [1] or [2].

[4] The evaluation unit acquires information on the moisture content in the air in the cultivation chamber from the output of the environment sensor, and evaluates the transpiration rate of the plants in the cultivation chamber based on the rate of change in the moisture content in the air. (S17),
The plant cultivation system according to the above [1] or [2].

[5] A connection switching unit (on-off valves 21, 22) capable of switching between connection and non-connection between the cultivation room and the air environment adjustment unit;
a control unit (40) that controls the connection switching unit;
The control unit controls the connection switching unit based on predetermined upper and lower limits, and controls the connection switching unit when the concentration of carbon dioxide in the cultivation chamber rises and reaches the upper limit. closes the air flow path between the cultivation room and the air environment adjustment unit (S14), and when the concentration of carbon dioxide in the cultivation room decreases and reaches the lower limit, the connection switching unit is controlled to control the opening an air flow path between the cultivation room and the air environment adjusting unit (S20);
The plant cultivation system according to any one of [1] to [4] above.

[6] A cultivation environment adjustment unit (control unit 40) that controls the cultivation environment of the plant in the cultivation container;
The cultivation environment adjustment unit reflects the evaluation result of the evaluation unit in the cultivation environment adjustment of the plant in the cultivation container (S18),
The plant cultivation system according to any one of [1] to [5] above.

[7] The cultivation chamber has an air outlet (10b) and an air inlet (10a) formed in the semi-enclosed space,
The air environment adjustment unit includes an air pipeline (20) connectable to the air outlet and the air inlet of the cultivation room, and a temperature and humidity adjustment unit that adjusts the temperature and humidity of the air passing through the air pipeline. (Air conditioning unit 23) and a carbon dioxide supply unit (cylinder 24) that supplies carbon dioxide to the air pipeline,
The connection switching unit has two on-off valves (on-off valves 21 and 22) arranged near the air outlet of the cultivation room and near the air inlet of the cultivation room, respectively.
The plant cultivation system according to [5] above.

[8] The cultivation environment adjustment unit controls the cultivation environment of the plant in the cultivation container so as to adjust the growth rate of the plant based on the results of evaluating the photosynthesis of the plant.
The plant cultivation system according to [6] above.
[9] A camera (18) for acquiring image data of the plant,
The plant cultivation system according to any one of [1] to [8] above.

Reference Signs List 10, 10A, 10B, 10C, 10D Cultivation chamber 10a Air inlet 10b Air outlet 11 Semi-enclosed space 12 Cultivation container 13 Plant 14 Nutrient solution 15 Lighting device 16 Blower 17 Air environment measuring device 18 Camera 20 Air pipe 20a Pipe inlet 20b Pipeline outlets 21, 22 On-off valve 23 Air conditioning section 24 Cylinder 25 Supply line 25a Supply point 31 Nutrient solution supply pipe 32 Nutrient solution discharge pipe 33 Nutrient solution tank 34 Fertilizer supply source 35 Fertilizer supply unit 36 pH measuring device 37 Pump 40 Control Section 50 Plant Cultivation System 61 Data Management Section 62 Data Storage Section 63 Photosynthesis Evaluation Section 64 Cultivation Environment Determination Section 100 Plant Factory i17 Measurement Result Information SG1, SG2 Control Signal TB1 Correction Data Storage Section Tm Measurement Section VU Upper Limit VL Lower Limit

Claims (9)

a cultivation chamber in which a semi-enclosed space isolated from the outside air can be formed;
a cultivation container that is arranged in the cultivation chamber and that can be used for cultivating plants;
an air environment adjustment unit that forms a substantially closed space with the cultivation room and is capable of adjusting the air environment in the cultivation room;
an environment sensor capable of detecting at least one of carbon dioxide and moisture in the cultivation room or in the vicinity of a portion where air enters and exits the cultivation room;
an evaluation unit that evaluates the cultivation environment of the plant in the cultivation container based on carbon dioxide or moisture detected by the environment sensor;
with
The evaluation unit evaluates the cultivation environment of the plant in the cultivation container based on changes in carbon dioxide or moisture detected by the environment sensor in a state where the air environment in the cultivation room has reached a reference state.
plant cultivation system. a correction data holding unit that holds correction data generated in advance based on the measurement result of a predetermined reference measuring instrument having detection accuracy higher than that of the environment sensor;
The evaluation unit evaluates the cultivation environment of the plant in the cultivation container based on the result of correcting the detection value of the environment sensor using the correction data.
The plant cultivation system according to claim 1. The evaluation unit acquires information on the carbon dioxide concentration in the cultivation room from the output of the environment sensor, and evaluates the photosynthetic rate or the respiration rate in the dark period of the plants in the cultivation room based on the rate of change in the carbon dioxide concentration. ,
The plant cultivation system according to claim 1 or 2. The evaluation unit acquires information on the amount of moisture in the air in the cultivation chamber from the output of the environment sensor, and evaluates the transpiration rate of the plants in the cultivation chamber based on the rate of change in the amount of moisture in the air.
The plant cultivation system according to claim 1 or 2. a connection switching unit capable of switching between the presence or absence of connection between the cultivation room and the air environment adjustment unit;
a control unit that controls the connection switching unit;
The control unit controls the connection switching unit based on predetermined upper and lower limits, and controls the connection switching unit when the concentration of carbon dioxide in the cultivation chamber rises and reaches the upper limit. to close the air flow path between the cultivation room and the air environment adjustment section, and when the concentration of carbon dioxide in the cultivation room decreases and reaches the lower limit, the connection switching section is controlled to close the cultivation room and the air environment adjustment section. opening an air flow path between the air environment adjustment unit;
The plant cultivation system according to any one of claims 1 to 4. A cultivation environment adjustment unit that controls the cultivation environment of the plant in the cultivation container,
The cultivation environment adjustment unit reflects the evaluation result of the evaluation unit in adjusting the cultivation environment of the plant in the cultivation container.
The plant cultivation system according to any one of claims 1 to 5. The cultivation chamber has an air outlet and an air inlet formed in the semi-enclosed space,
The air environment adjustment section includes an air conduit connectable to the air outlet and the air inlet of the cultivation chamber, a temperature and humidity adjustment section that adjusts the temperature and humidity of the air passing through the air conduit, and the a carbon dioxide supply unit that supplies carbon dioxide to the air conduit;
The connection switching unit has two on-off valves arranged near an air outlet of the cultivation room and near an air inlet of the cultivation room, respectively.
The plant cultivation system according to claim 5. The cultivation environment adjustment unit controls the cultivation environment of the plant in the cultivation container so as to adjust the growth rate of the plant based on the result of evaluating the photosynthesis of the plant.
The plant cultivation system according to claim 6. A camera that acquires image data of the plant,
The plant cultivation system according to any one of claims 1 to 8.

Images