JP7796620B2 - Irrigation Control System - Google Patents

Description

The present invention relates to an irrigation control system equipped with an imaging unit that captures images of the leaves of cultivated plants.

An example of an irrigation control system like the one described above is already known, such as that described in Patent Document 1. In this irrigation control system, the projected area of the leaves of a cultivated plant is calculated based on images captured by a camera.

Furthermore, this irrigation control system calculates the projection area ratio, which is the ratio of the projection area to the maximum projection area. If the projection area ratio falls below the water supply reference value, irrigation (referred to as "water supply" in Patent Document 1) is performed on the cultivated plants.

Japanese Patent Application Laid-Open No. 2007-306846

In the irrigation control system described above, the maximum projected area is the maximum value of the projected area since the most recent irrigation. In other words, this maximum projected area is updated each time irrigation is performed.

In horticultural facilities, managers perform cultivation management tasks such as hanging down, training, leaf removal, and harvesting. When cultivation management tasks are performed, the posture of cultivated plants and the position of their leaves change. When this happens, the projected area ratio is likely to change suddenly.

If the projected area ratio suddenly decreases as a result of cultivation management work, the projected area ratio may immediately fall below the irrigation standard value, but once irrigation is carried out, the maximum projected area will be updated. The updated maximum projected area corresponds to the state of the cultivated plants after the cultivation management work. Therefore, if the projected area ratio suddenly decreases as a result of cultivation management work, the impact on irrigation control will be relatively small.

However, if the projected area ratio increases sharply as a result of cultivation management work, it is possible that the wilting of the leaves will progress, and even at their most wilted, the projected area ratio may not fall below the water supply standard value. In this case, irrigation will not be carried out, and the cultivated plants may wither and die.

The object of the present invention is to provide an irrigation control system that makes it easy to continue appropriate irrigation when the condition of cultivated plants changes due to cultivation management work.

The present invention is characterized in that the irrigation control system includes an imaging unit that images leaves of a cultivated plant; a firmness index value calculation unit that calculates a firmness index value that indicates the degree of firmness of the leaves based on the image acquired by the imaging unit; a reference index value setting unit that sets the firmness index value at a reference time as a reference index value; a reference calculation unit that calculates an irrigation reference value based on the reference index value; an irrigation instruction unit that outputs an irrigation instruction signal when the firmness index value falls below the irrigation reference value; and a correction unit that corrects the reference index value when a predetermined condition is satisfied. When the reference index value is corrected by the correction unit, the reference calculation unit recalculates the irrigation reference value based on the corrected reference index value. The irrigation control system further includes a judgment value determination unit that determines a judgment value for correction of the reference index value, and a judgment value setting unit that determines a judgment value for correction of the reference index value based on the total time during which the firmness index value exceeds the judgment value between a first time point and a second time point, or a time during which the firmness index value exceeds the judgment value between the first time point and a second time point. and a time calculation unit that calculates the total time during which the tension index value is below the judgment value between two time points, wherein the correction unit decides whether to correct the reference index value based on the calculation result by the time calculation unit, and the apparatus comprises an upper judgment value determination unit that is the judgment value determination unit, and an upper time calculation unit that is the time calculation unit, wherein the upper judgment value determination unit determines an upper judgment value that is the judgment value based on the reference index value, and the upper time calculation unit calculates an upper state time that is the total time during which the tension index value is above the upper judgment value between the first time point and the second time point, and the correction unit decides whether to correct the reference index value based on the upper state time, and the correction unit decides to correct the reference index value when the ratio of the upper state time to the judgment time, which is the length from the first time point to the second time point, is equal to or greater than a predetermined ratio .

When the condition of cultivated plants changes due to cultivation management work, the trend in the firmness index value is likely to differ from the trend before the cultivation management work. For example, if the firmness index value increases sharply as a result of cultivation management work, such as by bringing the leaves closer to the imaging unit, the firmness index value will tend to fluctuate in a higher range than before the cultivation management work. Also, if the firmness index value decreases sharply as a result of cultivation management work, such as by moving the leaves away from the imaging unit, the firmness index value will tend to fluctuate in a lower range than before the cultivation management work.

Here, with this configuration, whether or not to modify the reference index value is determined based on the total time that the tension index value is above the judgment value, or the total time that the tension index value is below the judgment value. Therefore, it is easy to implement a configuration in which the reference index value is modified when the tension index value is trending in a range higher than the range before the cultivation management work, or when the tension index value is trending in a range lower than the range before the cultivation management work. Then, when the reference index value is modified, the irrigation reference value is recalculated. This makes it easier to continue appropriate irrigation.

Therefore, with this configuration, it is possible to realize an irrigation control system that can easily continue appropriate irrigation even when the condition of cultivated plants changes due to cultivation management work.
This configuration makes it easy to realize a configuration in which the reference index value is corrected if the firmness index value remains in a range higher than the range before the cultivation management work between the first and second time points. When the reference index value is corrected, the irrigation reference value is recalculated. This makes it easy to continue appropriate irrigation even if the firmness index value suddenly increases as a result of the cultivation management work, for example, because the leaves have come closer to the imaging unit.
According to this configuration, if the firmness index value remains in a range higher than the range before the cultivation management work between the first and second time points, the reference index value is easily corrected. As a result, if the firmness index value increases sharply as a result of the cultivation management work, for example, because the leaves have come closer to the imaging unit, it is easy to reliably continue appropriate irrigation.

Another feature of the present invention is an irrigation control system comprising: an imaging unit that images leaves of a cultivated plant; a firmness index value calculation unit that calculates a firmness index value that indicates the degree of firmness of the leaves based on the image acquired by the imaging unit; a reference index value setting unit that sets the firmness index value at a reference time as a reference index value; a reference calculation unit that calculates an irrigation reference value based on the reference index value; an irrigation instruction unit that outputs an irrigation instruction signal when the firmness index value falls below the irrigation reference value; and a correction unit that corrects the reference index value when a predetermined condition is satisfied, wherein when the reference index value is corrected by the correction unit, the reference calculation unit recalculates the irrigation reference value based on the corrected reference index value, and and a time calculation unit that calculates the total time during which the tension index value is below the judgment value between the first time point and the second time point, and the correction unit decides whether or not to correct the reference index value based on the calculation result by the time calculation unit, and the correction unit comprises a lower judgment value determination unit that is the judgment value determination unit, and a lower time calculation unit that is the time calculation unit, and the lower judgment value determination unit determines a lower judgment value that is the judgment value based on the irrigation reference value, and the lower time calculation unit calculates a lower state time that is the total time during which the tension index value is below the lower judgment value between the first time point and the second time point, and the correction unit decides whether or not to correct the reference index value based on the lower state time, and the correction unit decides to correct the reference index value if the ratio of the lower state time to the judgment time, which is the length from the first time point to the second time point, is equal to or greater than a predetermined ratio.
According to this configuration, whether to modify the reference index value is determined based on the total time that the tension index value is above the judgment value or the total time that the tension index value is below the judgment value. Therefore, it is easy to realize a configuration in which the reference index value is modified when the tension index value is trending in a range higher than the range before the cultivation management work or when the tension index value is trending in a range lower than the range before the cultivation management work. Then, when the reference index value is modified, the irrigation reference value is recalculated. This makes it easier to continue appropriate irrigation.
Therefore, with this configuration, it is possible to realize an irrigation control system that can easily continue appropriate irrigation even when the condition of cultivated plants changes due to cultivation management work.
This configuration makes it easy to realize a configuration in which the reference index value is corrected if the firmness index value remains in a range lower than the range before the cultivation management work between the first and second time points. When the reference index value is corrected, the irrigation reference value is recalculated. This makes it easy to continue appropriate irrigation even if the firmness index value suddenly decreases as a result of the cultivation management work, for example, because the leaves have moved away from the imaging unit.
According to this configuration, if the firmness index value remains within a range lower than the range before the cultivation management work between the first and second time points, the reference index value is easily corrected. As a result, if the firmness index value suddenly decreases as a result of the cultivation management work, for example, because the leaves have moved away from the imaging unit, it is easy to reliably continue appropriate irrigation.
Another feature of the present invention is a method for producing a cultivated plant, comprising: an imaging unit that images leaves of a cultivated plant; a firmness index value calculation unit that calculates a firmness index value that indicates the degree of firmness of the leaves based on the image acquired by the imaging unit; a reference index value setting unit that sets the firmness index value at a reference time as a reference index value; a reference calculation unit that calculates an irrigation reference value based on the reference index value; an irrigation instruction unit that outputs an irrigation instruction signal when the firmness index value falls below the irrigation reference value; and a correction unit that corrects the reference index value when a predetermined condition is satisfied, and when the reference index value is corrected by the correction unit, the reference calculation unit sets the irrigation reference value based on the corrected reference index value. An irrigation control system that recalculates the tension index value includes a judgment value determination unit that determines a judgment value for correcting the reference index value, and a time calculation unit that calculates the total time during which the tension index value exceeds the judgment value between a first time point and a second time point, or the total time during which the tension index value is below the judgment value between the first time point and the second time point, wherein the correction unit determines whether to correct the reference index value based on the calculation result by the time calculation unit, and the irrigation instruction unit limits the output of the irrigation instruction signal so that the number of times the irrigation instruction signal is output within a specified time limit is within a specified limit.
According to this configuration, whether to modify the reference index value is determined based on the total time that the tension index value is above the judgment value or the total time that the tension index value is below the judgment value. Therefore, it is easy to realize a configuration in which the reference index value is modified when the tension index value is trending in a range higher than the range before the cultivation management work or when the tension index value is trending in a range lower than the range before the cultivation management work. Then, when the reference index value is modified, the irrigation reference value is recalculated. This makes it easier to continue appropriate irrigation.
Therefore, with this configuration, it is possible to realize an irrigation control system that can easily continue appropriate irrigation even when the condition of cultivated plants changes due to cultivation management work.
This configuration makes it possible to avoid a situation in which watering is carried out relatively many times in a short period of time, thereby preventing overwatering.
Another feature of the present invention is a method for controlling a plant growth rate by using a leaf tension index calculation unit that calculates a leaf tension index value indicating the degree of leaf tension based on the captured image obtained by the image calculation unit, a reference index value setting unit that sets the leaf tension index value at a reference time as a reference index value, a reference calculation unit that calculates a watering reference value based on the reference index value, an irrigation instruction unit that outputs an irrigation instruction signal when the leaf tension index value falls below the irrigation reference value, and a correction unit that corrects the reference index value when a predetermined condition is satisfied, and when the reference index value is corrected by the correction unit, the reference calculation unit The irrigation control system includes a judgment value determination unit that determines a judgment value for correcting the reference index value, and a time calculation unit that calculates the total time during which the tension index value exceeds the judgment value between a first time point and a second time point, or the total time during which the tension index value is below the judgment value between the first time point and the second time point, wherein the correction unit determines whether to correct the reference index value based on the calculation result by the time calculation unit, and the irrigation instruction unit is configured not to output the next irrigation instruction signal until a predetermined time interval has elapsed since the time the irrigation instruction signal was output.
According to this configuration, whether to modify the reference index value is determined based on the total time that the tension index value is above the judgment value or the total time that the tension index value is below the judgment value. Therefore, it is easy to realize a configuration in which the reference index value is modified when the tension index value is trending in a range higher than the range before the cultivation management work or when the tension index value is trending in a range lower than the range before the cultivation management work. Then, when the reference index value is modified, the irrigation reference value is recalculated. This makes it easier to continue appropriate irrigation.
Therefore, with this configuration, it is possible to realize an irrigation control system that can easily continue appropriate irrigation even when the condition of cultivated plants changes due to cultivation management work.
This configuration can prevent watering from being repeated immediately after watering has been performed, thereby preventing overwatering.
Furthermore, in the present invention, it is preferable that the second point in time is the current time, and the first point in time is a point in time a predetermined time before the second point in time.

With this configuration, the irrigation reference value is more likely to be recalculated earlier when the state of the cultivated plants changes due to cultivation management work, compared to a configuration in which the second time point is a time point earlier than the current time.

For example, in a configuration in which a decision is made as to whether to revise the reference index value based on the change in the tension index value over a predetermined period of time from a first point in time to a second point in time, if the second point in time is five minutes before the current time, even if the tension index value changes within a range higher or lower than the range before the cultivation management work between the first point in time (e.g., 11:10) and the second point in time (e.g., 11:20), the decision to revise the reference index value will not be made until five minutes have passed since the second point in time (e.g., 11:25). This means that the irrigation reference value is recalculated relatively late.

In contrast, if the second time point (e.g., 11:20) is the current time, and the tension index value fluctuates between the first and second time points within a range higher or lower than the range before the cultivation management work, a decision can be made promptly (e.g., at 11:20) to revise the reference index value. This allows the irrigation reference value to be recalculated relatively quickly.

As a result, this configuration makes it possible to realize an irrigation control system that can quickly respond to changes in the condition of cultivated plants due to cultivation management work.

FIG. 2 is a plan view showing the entire interior of the horticultural facility. FIG. 2 is a side view showing the entire interior of the horticultural facility. FIG. 2 is a block diagram showing the configuration of an irrigation control system. FIG. FIG. 10 is a diagram showing an example of a change in coverage rate. FIG. 10 is a diagram showing an example of the transition of the coverage rate when cultivation management work is performed. FIG. 10 is a diagram showing an example of the transition of the coverage rate when cultivation management work is performed. FIG. 10 is a diagram showing the timing of irrigation when the repetitive irrigation interval is 15 minutes. FIG. 10 is a diagram showing the timing of irrigation when the repeated irrigation interval is 10 minutes. A diagram showing the timing of irrigation when a repeated irrigation time limit and a repeated irrigation number limit are set.

[Configuration of horticultural facilities]
An embodiment of the present invention will be described with reference to the drawings. In this embodiment, ridges A1 to A8 for planting cultivated plants P (see FIG. 2) are arranged vertically and horizontally in a horticultural facility 10 as shown in FIG. 1. Paths are provided between each ridge A for personnel responsible for caring for the cultivated plants P to pass through. The horticultural facility 10 may be, for example, a greenhouse or a solar-powered plant factory.

Each ridge A is made of, for example, a non-porous hydrophilic film. Cultivated plants P, such as tomatoes, are planted in each ridge A. As shown in Figures 1 and 2, an imaging unit Ca is provided suspended from the ceiling inside the horticultural facility 10 above the ridge A where the cultivated plants P are planted. The number of imaging units Ca provided may be one, or two or more.

The imaging unit Ca is a fixed-point camera equipped with, for example, a CCD or CMOS element, and is configured to capture visible light visible to the naked eye. The imaging unit Ca then captures images of the leaves P1 (see Figure 4) of the cultivated plant P at predetermined time intervals. In this way, the imaging unit Ca acquires captured images V (see Figure 4) over time.

Although not shown, the horticultural facility 10 is also equipped with environmental sensors, side windows, blackout curtains, heat pump air conditioning equipment, etc.

As shown in Figures 1 and 2, the imaging unit Ca is located directly above the ridge A2. The imaging unit Ca captures images of the cultivated plants P planted in the ridge A2 in a planar view from directly above. In other words, the imaging unit Ca is positioned above the cultivated plants P and captures images downward from a bird's-eye view.

[Configuration of irrigation control system]
3, the irrigation control system S in this embodiment includes an input device 2 and a management computer 4. The input device 2 is not particularly limited, and may be, for example, a keyboard or a mouse. The horticultural facility 10 is also included in the irrigation control system S.

That is, the irrigation control system S is equipped with an imaging unit Ca that captures images of the leaves P1 of the cultivated plant P.

As shown in FIG. 3, the horticultural facility 10 has an irrigation system 11. The irrigation system 11 includes, for example, irrigation tubes. The irrigation system 11 is configured to irrigate cultivated plants P. In the present invention, "irrigation" refers to the supply of nutrient solution. The nutrient solution may be a liquid in which fertilizer or the like is dissolved, or it may be simply water.

[Irrigation based on coverage]
As shown in Figure 3, the management computer 4 has a watering instruction unit 41, a coverage calculation unit 44 (corresponding to the ``firmness index value calculation unit'' of the present invention), a standard coverage setting unit 45 (corresponding to the ``standard index value setting unit'' of the present invention), a standard calculation unit 46, and a wilting coefficient setting unit 47.

As shown in Figure 3, the captured images V (see Figure 4) acquired by the imaging unit Ca at predetermined time intervals are sent to the coverage calculation unit 44. The coverage calculation unit 44 calculates the coverage E over time based on the received captured images V.

The coverage rate E is the proportion of the area occupied by the leaf P1 in the measurement area B (see Figure 4), which is the area in the captured image V where the leaf P1 appears. The coverage rate E is also a value that indicates the degree of firmness of the leaf P1. In other words, the coverage rate E corresponds to the "firmness index value" according to the present invention.

To explain in more detail how the coverage rate E is calculated, as shown in Figure 4, the coverage rate calculation unit 44 determines the areas of branches, leaves, and stems in the captured image V based on color information, etc., of the captured image V. This area is determined to be an area where the cultivated plant P is overgrown, i.e., a covered area.

Note that the determination of branch, leaf, and stem areas may be based on RGB data or YUV data. However, in this embodiment, in order to accommodate changes in light and darkness that occur with changes in weather and time of day, it is preferable to determine branch, leaf, and stem areas based on YUV data.

Then, based on the determination of the covered area, the range in the captured image V where the cultivated plant P is located is set. As shown in Figure 4, an area surrounded by four sides is set as the area in which the branches and leaves of the cultivated plant P are captured, and this area surrounded by four sides is set as the measurement area B, and the area Bs of the measurement area B is calculated. The area Bs can be calculated by counting the number of dots (the smallest unit of pixel in the captured image V) in the measurement area B of the captured image V.

Furthermore, the leaf area B1 can be calculated by counting the number of dots in the covered area. Then, the ratio of the leaf area B1 to the area Bs is calculated as the coverage rate E using the following formula:

Coverage ratio E = leaf area B1 / area Bs

It is desirable that the area Bs of the measurement region B be fixed at the area Bs before the leaves P1 began to wilt, even if the leaves P1 wilt over time and the area showing the branches and leaves gradually narrows. In other words, it is desirable that the area Bs be fixed at the area Bs calculated based on the first captured image V of the multiple captured images V acquired over time, and that only the leaf area B1 change over time.

As such, the irrigation control system S is equipped with a coverage calculation unit 44 that calculates the coverage rate E, which is a value indicating the degree of firmness of the leaves P1, based on the captured image V acquired by the imaging unit Ca.

As shown in FIG. 3, the coverage rate E calculated over time by the coverage rate calculation unit 44 is sent to the irrigation instruction unit 41 and the reference coverage rate setting unit 45. The reference coverage rate setting unit 45 sets the coverage rate E at the reference time as the reference coverage rate ST (corresponding to the "reference index value" according to the present invention). In other words, the irrigation control system S is equipped with a reference coverage rate setting unit 45 that sets the coverage rate E at the reference time as the reference coverage rate ST.

More specifically, in this embodiment, the reference time is the time period immediately after sunrise. Also, as described above, the imaging unit Ca acquires captured images V at predetermined time intervals. That is, the imaging unit Ca acquires captured images V at multiple times during the time period immediately after sunrise. As a result, the imaging unit Ca acquires multiple captured images V during the time period immediately after sunrise.

The coverage calculation unit 44 calculates multiple coverage rates E based on multiple captured images V acquired in the time period immediately after sunrise. The reference coverage setting unit 45 then sets the 90th percentile value of these multiple coverage rates E as the reference coverage rate ST.

However, the present invention is not limited to this, and the reference coverage setting unit 45 may be configured to set a value other than the 90th percentile value of the above-mentioned multiple coverage rates E as the reference coverage rate ST. For example, the reference coverage setting unit 45 may be configured to set the maximum value of the above-mentioned multiple coverage rates E as the reference coverage rate ST. Furthermore, the reference coverage setting unit 45 may be configured to set the average value of the above-mentioned multiple coverage rates E as the reference coverage rate ST.

As shown in Figure 3, the reference coverage rate ST set by the reference coverage rate setting unit 45 is sent to the reference calculation unit 46.

The administrator (user) can also input a wilting coefficient via the input device 2. The wilting coefficient is a coefficient that corresponds to the degree of wilting of the target leaf P1.

The wilting coefficient entered into the input device 2 is sent to the wilting coefficient setting unit 47. The wilting coefficient setting unit 47 then sets the wilting coefficient according to the administrator's input. The set wilting coefficient is sent to the reference calculation unit 46.

The reference calculation unit 46 calculates the irrigation reference value TH based on the reference coverage rate ST received from the reference coverage rate setting unit 45 and the wilting coefficient received from the wilting coefficient setting unit 47. More specifically, the reference calculation unit 46 calculates the irrigation reference value TH by multiplying the reference coverage rate ST by the wilting coefficient. The calculated irrigation reference value TH is sent to the irrigation instruction unit 41.

In this way, the irrigation control system S is equipped with a reference calculation unit 46 that calculates the irrigation reference value TH based on the reference coverage rate ST.

The irrigation instruction unit 41 determines whether the coverage rate E is below the irrigation standard value TH based on the coverage rate E received from the coverage rate calculation unit 44 and the irrigation standard value TH received from the standard calculation unit 46. If the coverage rate E is below the irrigation standard value TH, the irrigation instruction unit 41 outputs an irrigation instruction signal to the irrigation device 11.

As such, the irrigation control system S is equipped with an irrigation instruction unit 41 that outputs an irrigation instruction signal when the coverage rate E falls below the irrigation reference value TH.

Furthermore, if the coverage rate E does not exceed the irrigation reference value TH after the irrigation instruction unit 41 outputs an irrigation instruction signal, the irrigation instruction unit 41 outputs an additional irrigation instruction signal to the irrigation device 11.

The irrigation device 11 performs irrigation in accordance with the irrigation instruction signal received from the irrigation instruction unit 41.

With the configuration described above, as shown in Figure 5, the coverage rate E basically changes as follows: First, leaf P1 begins to wilt over time. As a result, the coverage rate E decreases over time.

When the coverage rate E falls below the irrigation standard value TH and irrigation is performed, the firmness of the leaf P1 recovers. This causes the coverage rate E to increase.

After that, leaf P1 will continue to wilt over time, and then regain its firmness through watering. As a result, the coverage rate E will alternate between increasing and decreasing.

In the example shown in Figure 5, the timing at which the irrigation instruction signal is output by the irrigation instruction unit 41 is indicated by an upward arrow. In this example, the irrigation instruction signal is output at time t1, time t2, time t3, time t4, and time t5.

Here, at times t1, t2, and t5, the coverage rate E falls below the irrigation reference value TH, so the irrigation instruction unit 41 outputs an irrigation instruction signal. As a result of this, irrigation is performed, and the coverage rate E exceeds the irrigation reference value TH.

However, at time t3, even though an irrigation instruction signal was output as at times t1, t2, and t5, the coverage rate E did not exceed the irrigation reference value TH until time t4.

Therefore, at time t4, the irrigation instruction unit 41 outputs an additional irrigation instruction signal. As a result, the coverage rate E exceeds the irrigation reference value TH.

In this embodiment, each element included in the management computer 4, such as the irrigation instruction unit 41, may be a functional unit in software, or may be configured as a physical device such as a microcomputer.

[Regarding recalculation of irrigation standard values]
In the horticultural facility 10, a manager performs cultivation management tasks such as hanging down, training, defoliation, and harvesting. When cultivation management tasks are performed, the posture of the cultivated plants P and the position of the leaves P1 change. This tends to cause a sudden change in the leaf area B1 in the captured image V acquired by the imaging unit Ca. When the leaf area B1 in the captured image V changes suddenly, the coverage rate E also changes suddenly.

In this case, if the coverage rate E increases suddenly, the irrigation standard value TH calculated based on the state of the cultivated plant P before the cultivation management work will become too low after the cultivation management work.

Conversely, if the coverage rate E suddenly decreases, the irrigation standard value TH calculated based on the state of the cultivated plant P before the cultivation management work will be too high after the cultivation management work.

For this reason, in this embodiment, the irrigation reference value TH is recalculated if the coverage rate E changes suddenly. The recalculation of the irrigation reference value TH is explained below.

As shown in FIG. 3, the management computer 4 has a calculation processing unit 42 and a correction unit 43. The calculation processing unit 42 includes an upper judgment value determination unit 51 and a lower judgment value determination unit 52. The correction unit 43 is configured to correct the standard coverage rate ST when predetermined conditions, described below, are met. In other words, the irrigation control system S is equipped with a correction unit 43 that corrects the standard coverage rate ST when predetermined conditions are met.

The upper judgment value determination unit 51 and the lower judgment value determination unit 52 are both judgment value determination units G. The judgment value determination unit G is configured to determine the judgment value J. The judgment value J is a value related to the correction of the reference coverage rate ST.

In this way, the irrigation control system S is equipped with a judgment value determination unit G that determines a judgment value J related to the correction of the standard coverage rate ST. More specifically, the irrigation control system S is equipped with an upper judgment value determination unit 51, which is the judgment value determination unit G, and a lower judgment value determination unit 52, which is the judgment value determination unit G.

As shown in FIG. 3, the calculation processing unit 42 also has an upper time calculation unit 53 and a lower time calculation unit 54. Both the upper time calculation unit 53 and the lower time calculation unit 54 are time calculation units K. The time calculation unit K is configured to calculate the total time during which the coverage rate E exceeds the judgment value J between the first and second time points, or the total time during which the coverage rate E falls below the judgment value J between the first and second time points.

In this embodiment, the second point in time is the current time, although this is not a limitation. The first point in time is a point in time that is a predetermined time before the second point in time. The length of this "predetermined time" is not particularly limited. For example, the first point in time may be 15 minutes before the second point in time, or may be 10 minutes before the second point in time.

In this way, the irrigation control system S is equipped with a time calculation unit K that calculates the total time during which the coverage rate E exceeds the judgment value J between the first and second time points, or the total time during which the coverage rate E falls below the judgment value J between the first and second time points. More specifically, the irrigation control system S is equipped with an upper time calculation unit 53, which is the time calculation unit K, and a lower time calculation unit 54, which is also the time calculation unit K.

As shown in FIG. 3, the upper judgment value determination unit 51 acquires the reference coverage rate ST from the reference coverage rate setting unit 45. The upper judgment value determination unit 51 determines the upper judgment value J1 (see FIG. 6) based on the reference coverage rate ST. Although not particularly limited, the upper judgment value determination unit 51 may, for example, determine a value 1.02 times the reference coverage rate ST as the upper judgment value J1.

The upper judgment value J1 is a value related to the correction of the standard coverage rate ST. In other words, the upper judgment value J1 is the judgment value J.

In this way, the upper judgment value determination unit 51 determines the upper judgment value J1, which is the judgment value J, based on the reference coverage rate ST.

The upper judgment value determination unit 51 sends the determined upper judgment value J1 to the upper time calculation unit 53. In addition, the coverage rate E calculated over time by the coverage rate calculation unit 44 is sent to the calculation processing unit 42. The upper time calculation unit 53 calculates the upper state time over time based on the upper judgment value J1 and the coverage rate E. The upper state time is the total time during which the coverage rate E exceeds the upper judgment value J1 between the first and second points in time.

In this way, the upper time calculation unit 53 calculates the upper state time, which is the total time during which the coverage rate E exceeds the upper determination value J1 between the first and second points in time.

As shown in FIG. 3, the correction unit 43 has a correction determination unit 55 and a correction execution unit 56. The upward state time calculated by the upward state time calculation unit 53 is sent to the correction determination unit 55. The correction determination unit 55 determines whether or not to correct the reference coverage rate ST based on the upward state time.

More specifically, the correction determination unit 55 stores a determination time TA (see Figure 6). The determination time TA is the length from the first time point to the second time point. The correction determination unit 55 determines whether the ratio of the upper state time to the determination time TA is equal to or greater than a predetermined ratio. If the ratio of the upper state time to the determination time TA is equal to or greater than the predetermined ratio, the correction determination unit 55 determines to correct the reference coverage rate ST. In this embodiment, this "predetermined ratio" is 60%. However, the present invention is not limited to this, and this "predetermined ratio" may be any ratio other than 60%.

In this way, the correction unit 43 decides to correct the reference coverage rate ST when the ratio of the upper state time to the determination time TA, which is the length from the first point in time to the second point in time, is equal to or greater than a predetermined ratio. In other words, the correction unit 43 decides whether to correct the reference coverage rate ST based on the upper state time.

The length of the judgment time TA is not particularly limited. For example, the length of the judgment time TA may be 15 minutes or 10 minutes. The length of the judgment time TA also corresponds to the length of the "predetermined time" described above.

When the correction determination unit 55 determines that the reference coverage rate ST should be corrected, as shown in FIG. 3, the correction determination unit 55 sends a correction instruction signal to the correction execution unit 56. Upon receiving the correction instruction signal, the correction execution unit 56 corrects the reference coverage rate ST set by the reference coverage rate setting unit 45.

At this time, the correction execution unit 56 corrects the reference coverage rate ST based on the coverage rate E from the first time point to the second time point. Although not particularly limited, for example, the correction execution unit 56 may correct the reference coverage rate ST by replacing it with the 90th percentile value of the coverage rate E from the first time point to the second time point. The corrected reference coverage rate ST is sent from the reference coverage rate setting unit 45 to the reference calculation unit 46.

When the standard coverage rate ST is revised by the revision execution unit 56, the standard calculation unit 46 recalculates the irrigation standard value TH based on the revised standard coverage rate ST. More specifically, the standard calculation unit 46 recalculates the irrigation standard value TH by multiplying the revised standard coverage rate ST by the wilting coefficient.

In this way, when the standard coverage rate ST is corrected by the correction unit 43, the standard calculation unit 46 recalculates the irrigation standard value TH based on the corrected standard coverage rate ST.

For example, in the example shown in Figure 6, the timing at which the irrigation instruction signal was output by the irrigation instruction unit 41 is indicated by an upward arrow. In this example, after irrigation is performed at time t11, cultivation management work is performed at time t12, causing a sudden increase in coverage rate E.

After that, from time t13 to time t14, the coverage rate E exceeds the upper judgment value J1. In this example, when the current time is time t14, time t13 corresponds to the above-mentioned "first time point," and time t14 corresponds to the above-mentioned "second time point."

When the current time is time t14, the upper state time matches the judgment time TA. In other words, the ratio of the upper state time to the judgment time TA is 100%. Therefore, the ratio of the upper state time to the judgment time TA is equal to or greater than the above-mentioned predetermined ratio. Therefore, the correction judgment unit 55 decides to correct the reference coverage rate ST.

As a result, at time t14, the correction execution unit 56 corrects the reference coverage rate ST. As a result, the reference coverage rate ST increases at time t14. The corrected reference coverage rate ST is sent to the reference calculation unit 46. The reference calculation unit 46 recalculates the irrigation reference value TH based on the corrected reference coverage rate ST. As a result, the irrigation reference value TH increases at time t14.

Note that the upper state time may include not only the time when the coverage rate E is greater than the upper judgment value J1, but also the time when the coverage rate E matches the upper judgment value J1. For example, in the example shown in Figure 6, at time t13, the coverage rate E may be greater than the upper judgment value J1, or the coverage rate E may be matched to the upper judgment value J1.

Also, as shown in FIG. 3, the lower judgment value determination unit 52 acquires the irrigation reference value TH from the reference calculation unit 46. The lower judgment value determination unit 52 determines the lower judgment value J2 (see FIG. 7) based on the irrigation reference value TH. Although not particularly limited, the lower judgment value determination unit 52 may, for example, determine a value 1.02 times the irrigation reference value TH as the lower judgment value J2.

The lower judgment value J2 is a value related to the correction of the standard coverage rate ST. In other words, the lower judgment value J2 is the judgment value J.

In this way, the lower judgment value determination unit 52 determines the lower judgment value J2, which is the judgment value J, based on the irrigation reference value TH.

The lower limit determination unit 52 sends the determined lower limit determination value J2 to the lower limit time calculation unit 54. In addition, the coverage rate E calculated over time by the coverage rate calculation unit 44 is sent to the calculation processing unit 42. The lower limit time calculation unit 54 calculates the lower limit state time over time based on the lower limit determination value J2 and the coverage rate E. The lower limit state time is the total time during which the coverage rate E is below the lower limit determination value J2 between the first and second points in time.

In this way, the below-level time calculation unit 54 calculates the below-level state time, which is the total time during which the coverage rate E is below the below-level determination value J2 between the first and second points in time.

As shown in FIG. 3, the downward state time calculated by the downward state time calculation unit 54 is sent to the correction determination unit 55. The correction determination unit 55 determines whether to correct the reference coverage rate ST based on the downward state time.

More specifically, the correction determination unit 55 determines whether the ratio of the downward state time to the determination time TA (see Figure 7) is equal to or greater than a predetermined ratio. If the ratio of the downward state time to the determination time TA is equal to or greater than the predetermined ratio, the correction determination unit 55 determines to correct the reference coverage rate ST. Note that this "predetermined ratio" is 60% in this embodiment. However, the present invention is not limited to this, and this "predetermined ratio" may be any ratio other than 60%.

In this way, the correction unit 43 decides to correct the reference coverage rate ST when the ratio of the downward state time to the determination time TA, which is the length from the first point in time to the second point in time, is equal to or greater than a predetermined ratio. In other words, the correction unit 43 decides whether to correct the reference coverage rate ST based on the downward state time.

The length of the judgment time TA when determining whether to revise the reference coverage rate ST based on the upper state time and the length of the judgment time TA when determining whether to revise the reference coverage rate ST based on the lower state time may be the same or different.

In addition, the administrator may be able to set the length of the judgment time TA when determining whether to revise the reference coverage rate ST based on the upper state time, and the length of the judgment time TA when determining whether to revise the reference coverage rate ST based on the lower state time.

The processing after the correction determination unit 55 decides to correct the reference coverage rate ST is as described above.

For example, in the example shown in Figure 7, the timing at which the irrigation instruction signal is output by the irrigation instruction unit 41 is indicated by an upward arrow. In this example, after irrigation is performed at time t21, cultivation management work is performed at time t22, causing the coverage rate E to drop sharply. As a result, the coverage rate E falls below the irrigation reference value TH.

Then, because the coverage rate E fell below the irrigation reference value TH, an irrigation instruction signal was output by the irrigation instruction unit 41 at time t22.

Then, between time t22 and time t23, the total time during which the coverage rate E falls below the lower judgment value J2 is relatively long. In this example, when the current time is time t23, time t22 corresponds to the above-mentioned "first time point," and time t23 corresponds to the above-mentioned "second time point."

In this example, when the current time is time t23, the ratio of the downward state time to the judgment time TA is 80%. Therefore, the ratio of the downward state time to the judgment time TA is equal to or greater than the above-mentioned predetermined ratio. Therefore, the correction determination unit 55 decides to correct the reference coverage rate ST.

As a result, at time t23, the correction execution unit 56 corrects the reference coverage rate ST. As a result, the reference coverage rate ST decreases at time t23. The corrected reference coverage rate ST is sent to the reference calculation unit 46. The reference calculation unit 46 recalculates the irrigation reference value TH based on the corrected reference coverage rate ST. As a result, the irrigation reference value TH decreases at time t23.

In addition, the lower state time may include not only the time when the coverage rate E is smaller than the lower determination value J2, but also the time when the coverage rate E is equal to the lower determination value J2.

With the configuration described above, the correction determination unit 55 determines whether or not to correct the reference coverage rate ST based on the upper state time calculated by the upper time calculation unit 53 and the lower state time calculated by the lower time calculation unit 54. In other words, the correction unit 43 determines whether or not to correct the reference coverage rate ST based on the calculation results by the time calculation unit K.

The above-mentioned "predetermined conditions" are the condition that "the proportion of the upper state time relative to the judgment time TA is equal to or greater than a predetermined proportion" and the condition that "the proportion of the lower state time relative to the judgment time TA is equal to or greater than a predetermined proportion." If the proportion of the upper state time relative to the judgment time TA is less than the predetermined proportion, and the proportion of the lower state time relative to the judgment time TA is less than the predetermined proportion, the correction determination unit 55 determines not to correct the reference coverage rate ST at this time.

When determining whether to revise the reference coverage rate ST based on the upward state time, the first point in time may be the point in time when the irrigation instruction signal is output by the irrigation instruction unit 41. In this case, the second point in time may be determined to be a point in time that is a determination time TA after the first point in time. In other words, the second point in time does not have to be the current time.

Furthermore, when determining whether to revise the standard coverage rate ST based on the downward state time, the first point in time may be the point in time when the irrigation instruction signal is output by the irrigation instruction unit 41. In this case, the second point in time may be determined to be a point in time that is a determination time TA after the first point in time. In other words, the second point in time does not have to be the current time.

Furthermore, in the example shown in Figure 6, not only the upper judgment value J1 but also the lower judgment value J2 may be determined. Further, in the example shown in Figure 7, not only the lower judgment value J2 but also the upper judgment value J1 may be determined.

[Repeated watering interval]
3, the management computer 4 has an interval setting unit 48. The manager can input the repetitive watering interval (corresponding to the "time interval" according to the present invention) via the input device 2.

The repeat watering interval entered into the input device 2 is sent to the interval setting unit 48. The interval setting unit 48 then sets the repeat watering interval according to the administrator's input. The set repeat watering interval is sent to the watering instruction unit 41.

In this embodiment, the irrigation instruction unit 41 does not output the next irrigation instruction signal until the repeat irrigation interval has elapsed from the time the irrigation instruction signal is output. In other words, the irrigation instruction unit 41 is configured not to output the next irrigation instruction signal until the predetermined repeat irrigation interval has elapsed from the time the irrigation instruction signal is output.

For example, in the example shown in Figure 8, the coverage rate E is plotted every minute. Also in Figure 8, the timing at which the irrigation instruction signal was output by the irrigation instruction unit 41 is indicated by an upward arrow. Also, at 10:14, the standard coverage rate ST was corrected and the irrigation standard value TH was recalculated.

In the example shown in Figure 8, the above-mentioned lower judgment value J2 coincides with the irrigation reference value TH. The above-mentioned judgment time TA is assumed to be 15 minutes (the time required for 15 plots). The repeated irrigation interval is set to 15 minutes.

In this example, after irrigation is performed at exactly 10:00, the coverage rate E falls below the lower judgment value J2 before the irrigation standard value TH is recalculated from 10:01, 10:02, 10:04, 10:06, and 10:14. Note that even at exactly 10:00, the coverage rate E falls below the lower judgment value J2. Therefore, at 10:14, the lower state time calculation unit 54 calculates the lower state time to be 13 minutes.

In this case, the ratio of the downward state time to the judgment time TA is equal to or greater than a predetermined ratio (60%). Therefore, the correction judgment unit 55 decides to correct the reference coverage rate ST. As a result, at 10:14, the correction execution unit 56 corrects the reference coverage rate ST. As a result, the reference coverage rate ST decreases at 10:14. The corrected reference coverage rate ST is sent to the reference calculation unit 46. The reference calculation unit 46 recalculates the irrigation reference value TH based on the corrected reference coverage rate ST. As a result, the irrigation reference value TH decreases at 10:14.

Furthermore, in this example, as described above, the repeat irrigation interval is set to 15 minutes. Therefore, the irrigation instruction unit 41 will not output the next irrigation instruction signal until 15 minutes have passed since exactly 10:00, when the irrigation instruction signal was output. Therefore, for example, even though the coverage rate E is below the irrigation reference value TH at 10:01, the irrigation instruction unit 41 will not output a irrigation instruction signal.

In the example shown in Figure 9, the coverage rate E is plotted for each minute. Also in Figure 9, the timing at which the irrigation instruction signal is output by the irrigation instruction unit 41 is indicated by an upward arrow.

In the example shown in Figure 9, the above-mentioned lower judgment value J2 coincides with the irrigation reference value TH. The above-mentioned judgment time TA is set to 15 minutes (the time required for 15 plots). The repeated irrigation interval is set to 10 minutes. The progression of the coverage rate E, the reference coverage rate ST, and the irrigation reference value TH (lower judgment value J2) in Figure 9 are the same as those in Figure 8.

In this example, similar to the example shown in Figure 8, at 10:14, the correction execution unit 56 corrects the standard coverage rate ST. As a result, the irrigation standard value TH decreases at 10:14.

Furthermore, in this example, as described above, the repeat irrigation interval is set to 10 minutes. Therefore, the irrigation instruction unit 41 does not output the next irrigation instruction signal until 10 minutes have passed since exactly 10:00, when the irrigation instruction signal was output. Therefore, for example, even though the coverage rate E is below the irrigation reference value TH at 10:01, the irrigation instruction unit 41 does not output a irrigation instruction signal.

Furthermore, at 10:10, the point when the repeated watering interval (10 minutes) has elapsed since exactly 10:00, the coverage rate E falls below the watering reference value TH. Therefore, at 10:10, the watering instruction unit 41 outputs a watering instruction signal.

[Limitation on the number of times of watering]
3, the management computer 4 has an irrigation control unit 49. The irrigation control unit 49 includes a time limit setting unit 57 and a number of limit setting unit 58. The manager can input the repeated irrigation time limit (corresponding to the "time limit" according to the present invention) and the number of repeated irrigation limit (corresponding to the "number of limit" according to the present invention) via the input device 2.

The repeated watering time limit and repeated watering count limit entered into the input device 2 are sent to the watering control unit 49. The time limit setting unit 57 then sets the repeated watering time limit in accordance with the administrator's input. The count limit setting unit 58 also sets the repeated watering count limit in accordance with the administrator's input. The set repeated watering time limit and repeated watering count limit are sent to the watering instruction unit 41.

In this embodiment, the irrigation instruction unit 41 is configured to limit the output of the irrigation instruction signal so that the number of times the irrigation instruction signal is output within the repeated irrigation time limit is within the repeated irrigation limit number. In other words, the irrigation instruction unit 41 limits the output of the irrigation instruction signal so that the number of times the irrigation instruction signal is output within a predetermined repeated irrigation time limit is within the predetermined repeated irrigation limit number.

For example, in the example shown in Figure 10, the coverage rate E is plotted every minute. Also in Figure 10, the timing at which the irrigation instruction signal is output by the irrigation instruction unit 41 is indicated by an upward arrow.

In the example shown in Figure 10, the lower judgment value J2 mentioned above coincides with the irrigation reference value TH. The judgment time TA mentioned above is set to 15 minutes (the time required for 15 plots). The repeated irrigation interval is set to 3 minutes. The progression of the coverage rate E, the reference coverage rate ST, and the irrigation reference value TH (lower judgment value J2) in Figure 10 are the same as those in Figure 8.

In the example shown in Figure 10, the repeat watering time limit and the repeat watering limit are set to 15 minutes and 3 times, respectively.

In this example, similar to the example shown in Figure 8, at 10:14, the correction execution unit 56 corrects the standard coverage rate ST. As a result, the irrigation standard value TH decreases at 10:14.

In this example, as described above, the repeat watering interval is set to three minutes. Therefore, the watering instruction unit 41 will not output the next watering instruction signal until three minutes have passed since exactly 10:00, when the watering instruction signal was output.

Furthermore, at 10:03, when the repeated watering interval (3 minutes) has elapsed since exactly 10:00, the coverage rate E does not fall below the watering reference value TH. Therefore, at 10:03, the watering instruction unit 41 does not output a watering instruction signal. Later, at 10:04, the coverage rate E falls below the watering reference value TH. Therefore, at 10:04, the watering instruction unit 41 outputs a watering instruction signal.

The irrigation instruction unit 41 does not output the next irrigation instruction signal until the repeat irrigation interval (3 minutes) has elapsed since 10:04, when the irrigation instruction signal was output. At 10:07, when the repeat irrigation interval (3 minutes) has elapsed since 10:04, the coverage rate E falls below the irrigation reference value TH. Therefore, at 10:07, the irrigation instruction unit 41 outputs a irrigation instruction signal.

As explained above, in this example, the irrigation instruction signal is output at exactly 10:00, 10:04, and 10:07. In other words, from exactly 10:00 within the repeated irrigation time limit (15 minutes), the irrigation instruction signal is output the same number of times as the repeated irrigation time limit (3 times). Therefore, after the third irrigation instruction signal is output at 10:07, the irrigation instruction unit 41 does not output any irrigation instruction signals until the repeated irrigation time limit (15 minutes) counted from exactly 10:00 has expired.

Therefore, for example, at 10:10, the irrigation interval (3 minutes) has elapsed since 10:07, and the coverage rate E is below the irrigation reference value TH, but the irrigation instruction unit 41 does not output an irrigation instruction signal. Similarly, at 10:13, for example, the irrigation instruction unit 41 does not output an irrigation instruction signal.

As explained above, when the state of cultivated plant P changes due to cultivation management work, the change in coverage rate E is likely to differ from the change before the cultivation management work. For example, if the coverage rate E increases sharply as a result of cultivation management work, for example, because leaf P1 moves closer to imaging unit Ca, coverage rate E will tend to change in a higher range than the range before the cultivation management work. Also, if the coverage rate E decreases sharply as a result of cultivation management work, for example, because leaf P1 moves farther away from imaging unit Ca, coverage rate E will tend to change in a lower range than the range before the cultivation management work.

Here, with the configuration described above, a decision is made as to whether or not to revise the standard coverage rate ST based on the total time that the coverage rate E is above the judgment value J, or the total time that the coverage rate E is below the judgment value J. This makes it easy to implement a configuration in which the standard coverage rate ST is revised when the coverage rate E is trending in a range higher than the range before the cultivation management work, or when the coverage rate E is trending in a range lower than the range before the cultivation management work. Then, when the standard coverage rate ST is revised, the irrigation standard value TH is recalculated. This makes it easier to continue appropriate irrigation.

Therefore, the configuration described above makes it possible to realize an irrigation control system S that can easily continue appropriate irrigation even when the condition of cultivated plants P changes due to cultivation management work.

Other Embodiments
(1) The upper judgment value determination unit 51 may determine the upper judgment value J1 to be the same value as the reference coverage rate ST.

(2) The upper judgment value determination unit 51 and the upper time calculation unit 53 may not be provided. In this case, the correction unit 43 may be configured to determine whether to correct the reference coverage rate ST based only on the lower state time out of the upper state time and the lower state time.

(3) The correction unit 43 may be configured to determine whether to correct the reference coverage rate ST without being based on the ratio of the upper state time to the determination time TA. For example, the correction unit 43 may be configured to determine to correct the reference coverage rate ST when the upper state time is equal to or longer than a predetermined length.

(4) The lower limit judgment value determination unit 52 and the lower limit time calculation unit 54 may not be provided. In this case, the correction unit 43 may be configured to determine whether to correct the reference coverage rate ST based only on the upper limit state time out of the upper limit state time and the lower limit state time.

(5) The correction unit 43 may be configured to determine whether to correct the reference coverage rate ST without being based on the ratio of the downward state time to the determination time TA. For example, the correction unit 43 may be configured to determine to correct the reference coverage rate ST when the downward state time is equal to or longer than a predetermined length.

(6) The interval setting unit 48 does not have to be provided. In other words, the configuration may not limit the output of the irrigation instruction signal based on the repeated irrigation interval.

(7) The irrigation control unit 49 does not have to be provided. In other words, the configuration may not limit the output of the irrigation instruction signal based on the repeated irrigation time limit and the repeated irrigation count limit.

The configurations disclosed in the above-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, provided no contradictions arise. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these embodiments. They can be modified as appropriate within the scope of the purpose of the present invention.

The present invention can be used in irrigation control systems equipped with an imaging unit that captures images of the leaves of cultivated plants.

41: Irrigation instruction unit 43: Correction unit 44: Coverage calculation unit (tension index value calculation unit)
45: Reference coverage setting unit (reference index value setting unit)
46: Reference calculation unit 51: Upper judgment value determination unit 52: Lower judgment value determination unit 53: Upper time calculation unit 54: Lower time calculation unit Ca: Imaging unit E: Coverage rate (tension index value)
G: Judgment value determination unit J: Judgment value J1: Upper judgment value J2: Lower judgment value K: Time calculation unit P: Cultivated plant P1: Leaf S: Irrigation control system ST: Standard coverage rate (standard index value)
TA: Judgment time TH: Irrigation reference value V: Captured image

Claims (5)

an imaging unit that captures an image of a leaf of a cultivated plant;
a tension index value calculation unit that calculates a tension index value that indicates a degree of tension of the leaves based on the captured image acquired by the imaging unit;
a reference index value setting unit that sets the tension index value at a reference time as a reference index value;
a reference calculation unit that calculates an irrigation reference value based on the reference index value;
an irrigation instruction unit that outputs an irrigation instruction signal when the tension index value falls below the irrigation reference value;
a correction unit that corrects the reference index value when a predetermined condition is satisfied,
When the reference index value is corrected by the correction unit, the reference calculation unit recalculates the irrigation reference value based on the corrected reference index value,
a judgment value determination unit that determines a judgment value regarding correction of the reference index value;
a time calculation unit that calculates a total time during which the tension index value is greater than the determination value between a first time point and a second time point, or a total time during which the tension index value is less than the determination value between the first time point and the second time point,
the correction unit determines whether to correct the reference index value based on a calculation result by the time calculation unit ;
an upper judgment value determination unit that is the judgment value determination unit;
an upper time calculation unit that is the time calculation unit,
the upper judgment value determination unit determines an upper judgment value, which is the judgment value, based on the reference index value;
the upper state time calculation unit calculates an upper state time, which is a total time during which the tension index value is above the upper determination value between the first time point and the second time point;
the correction unit determines whether to correct the reference index value based on the upward state time;
The correction unit is an irrigation control system that decides to correct the reference index value when the ratio of the upward state time to the judgment time, which is the length from the first point in time to the second point in time, is greater than or equal to a predetermined ratio . an imaging unit that captures an image of a leaf of a cultivated plant;
a tension index value calculation unit that calculates a tension index value that indicates a degree of tension of the leaves based on the captured image acquired by the imaging unit;
a reference index value setting unit that sets the tension index value at a reference time as a reference index value;
a reference calculation unit that calculates an irrigation reference value based on the reference index value;
an irrigation instruction unit that outputs an irrigation instruction signal when the tension index value falls below the irrigation reference value;
a correction unit that corrects the reference index value when a predetermined condition is satisfied,
When the reference index value is corrected by the correction unit, the reference calculation unit recalculates the irrigation reference value based on the corrected reference index value,
a judgment value determination unit that determines a judgment value regarding correction of the reference index value;
a time calculation unit that calculates a total time during which the tension index value is greater than the determination value between a first time point and a second time point, or a total time during which the tension index value is less than the determination value between the first time point and the second time point,
the correction unit determines whether to correct the reference index value based on a calculation result by the time calculation unit;
a lower judgment value determination unit that is the judgment value determination unit;
a lower time calculation unit that is the time calculation unit,
The lower judgment value determination unit determines a lower judgment value, which is the judgment value, based on the irrigation reference value;
the lower limit time calculation unit calculates a lower limit state time, which is a total time during which the tension index value is below the lower limit determination value between the first time point and the second time point;
the correction unit determines whether to correct the reference index value based on the downward state time;
The correction unit is an irrigation control system that decides to correct the reference index value when the ratio of the downward state time to the judgment time, which is the length from the first point in time to the second point in time, is greater than or equal to a predetermined ratio. an imaging unit that captures an image of a leaf of a cultivated plant;
a tension index value calculation unit that calculates a tension index value that indicates a degree of tension of the leaves based on the captured image acquired by the imaging unit;
a reference index value setting unit that sets the tension index value at a reference time as a reference index value;
a reference calculation unit that calculates an irrigation reference value based on the reference index value;
an irrigation instruction unit that outputs an irrigation instruction signal when the tension index value falls below the irrigation reference value;
a correction unit that corrects the reference index value when a predetermined condition is satisfied,
When the reference index value is corrected by the correction unit, the reference calculation unit recalculates the irrigation reference value based on the corrected reference index value,
a judgment value determination unit that determines a judgment value regarding correction of the reference index value;
a time calculation unit that calculates a total time during which the tension index value is greater than the determination value between a first time point and a second time point, or a total time during which the tension index value is less than the determination value between the first time point and the second time point,
the correction unit determines whether to correct the reference index value based on a calculation result by the time calculation unit;
The irrigation control system wherein the irrigation instruction unit limits the output of the irrigation instruction signal so that the number of times the irrigation instruction signal is output within a predetermined time limit is within a predetermined limit. an imaging unit that captures an image of a leaf of a cultivated plant;
a tension index value calculation unit that calculates a tension index value that indicates a degree of tension of the leaves based on the captured image acquired by the imaging unit;
a reference index value setting unit that sets the tension index value at a reference time as a reference index value;
a reference calculation unit that calculates an irrigation reference value based on the reference index value;
an irrigation instruction unit that outputs an irrigation instruction signal when the tension index value falls below the irrigation reference value;
a correction unit that corrects the reference index value when a predetermined condition is satisfied,
When the reference index value is corrected by the correction unit, the reference calculation unit recalculates the irrigation reference value based on the corrected reference index value,
a judgment value determination unit that determines a judgment value regarding correction of the reference index value;
a time calculation unit that calculates a total time during which the tension index value is greater than the determination value between a first time point and a second time point, or a total time during which the tension index value is less than the determination value between the first time point and the second time point,
the correction unit determines whether to correct the reference index value based on a calculation result by the time calculation unit;
An irrigation control system in which the irrigation instruction unit is configured not to output the next irrigation instruction signal until a predetermined time interval has elapsed since the irrigation instruction signal was output. the second time point is the current time,
The irrigation control system according to claim 1 , wherein the first point in time is a point in time that is a predetermined time before the second point in time.