Irrigation system, irrigation method, program, and computer-readable medium

Abstract

An irrigation system according to the present disclosure comprises: an irrigation device that supplies water to a plant; a control device that controls the operation of the irrigation device; and a first flow velocity sensor and a second flow velocity sensor that are installed at different positions so as to measure the flow velocity of sap flowing through the plant or the flow velocity of water flowing through the irrigation device. The control device controls the operation of the irrigation device on the basis of the correlation between the measurement value of the first flow velocity sensor and the measurement value of the second flow velocity sensor.

Description

Irrigation system, irrigation method, program, and computer-readable medium

[0001] The present disclosure relates to an irrigation system, an irrigation method, a program, and a computer-readable medium.

[0002] Irrigation systems and methods for irrigating plants are known.

[0003] Patent Document 1 discloses a growth environment control system that drives an environmental control device, including irrigation, based on the measurement results of a plurality of sensors, such as a sap flow sensor.

[0004] Patent Document 2 discloses a method for predicting the timing of irrigation based on changes in measurements of a sap flow sensor.

[0005] JP 2019-228370 A Patent No. 5366115 A

[0006] The technology of Patent Document 1 leaves room for improvement in that it uses a simple configuration to irrigate plants in a way that is more suited to their condition.The technology of Patent Document 2 irrigates plants based on a single pattern of change in sap flow rate, but leaves room for improvement in terms of accuracy, i.e., in terms of irrigating plants in a way that is more suited to their condition.

[0007] The present disclosure provides an irrigation system, an irrigation method, a program, and a computer-readable medium that can perform irrigation appropriate to the state of a plant using a simple configuration.

[0008] An irrigation system according to one aspect of the present disclosure comprises an irrigation device that supplies water to plants, a control device that controls the operation of the irrigation device, and a first flow velocity sensor and a second flow velocity sensor that are installed at different positions so as to measure the flow velocity of sap flowing through the plant or the flow velocity of water flowing through the irrigation device, and the control device controls the operation of the irrigation device based on the correlation between the measurement values ​​of the first flow velocity sensor and the measurement values ​​of the second flow velocity sensor.

[0009] An irrigation method according to one aspect of the present disclosure is a method for controlling the operation of an irrigation device that supplies water to plants, and controls the operation of the irrigation device based on the correlation between the measured values ​​of a first flow velocity sensor and a second flow velocity sensor that are installed at different positions so as to measure the flow rate of sap flowing through the plant or the flow rate of water flowing through the irrigation device.

[0010] A program according to one aspect of the present disclosure is a program for controlling the operation of an irrigation device that supplies water to plants, and when executed by a processor, causes the processor to control the operation of the irrigation device based on the correlation between the measured values ​​of a first flow rate sensor and a second flow rate sensor that are installed at different positions so as to measure the flow rate of sap flowing through the plant or the flow rate of water flowing through the irrigation device.

[0011] A computer-readable medium according to one aspect of the present disclosure is a computer-readable medium for controlling the operation of an irrigation device that supplies water to plants, and when executed by a processor, causes the processor to control the operation of the irrigation device based on the correlation between the measurements of a first flow rate sensor and a second flow rate sensor installed at different positions to measure the flow rate of sap flowing through the plant or the flow rate of water flowing through the irrigation device.

[0012] According to the present disclosure, irrigation suitable for the condition of a plant can be performed using a simple configuration.

[0013] Schematic diagram showing an irrigation system of embodiment 1. Diagram showing an algorithm relating to a method for controlling an irrigation device by the irrigation system of embodiment 1. Graph showing experimental results when the irrigation system of embodiment 1 is operated based on the algorithm shown in Figure 2 and a plant is irrigated twice. Schematic diagram showing an irrigation system according to a modified example of embodiment 1. Schematic diagram showing an irrigation system of embodiment 2. Diagram showing an algorithm relating to a method for controlling an irrigation device by the irrigation system of embodiment 2. Graph showing flow rate measurement results when three flow rate sensors are installed in the irrigation system and irrigation is repeated multiple times using both the algorithm shown in Figure 1 and the algorithm shown in Figure 6. Schematic diagram showing an irrigation system of embodiment 3. Diagram showing an algorithm relating to a method for controlling an irrigation device by the irrigation system of embodiment 3.

[0014] Hereinafter, exemplary embodiments of the irrigation system, irrigation method, and program according to the present disclosure will be described with reference to the accompanying drawings. The present disclosure is not limited to the specific configurations of the following embodiments, and configurations based on similar technical ideas are also included in the present disclosure.

[0015] First Embodiment First, with reference to FIG. 1, an irrigation system according to a first embodiment of the present disclosure will be described.

[0016] FIG. 1 is a schematic diagram showing an irrigation system 2 according to a first embodiment.

[0017] The irrigation system 2 shown in FIG. 1 is a system for irrigating a plant 4, and includes an irrigation device 6, a control device 8, and a plurality of flow rate sensors 10 and 12.

[0018] The irrigation device 6 is a device that supplies water to the plants 4. The irrigation device 6 has a liquid delivery unit 7 that delivers water, and the liquid delivery unit 7 is arranged so as to be able to deliver water to soil 9 in which the plants 4 are planted. The irrigation device 6 is connected to a control device 8.

[0019] The control device 8 is a device for controlling the irrigation system 2 including the irrigation device 6. The control device 8 is configured, for example, by a microcomputer including a processor and a memory that stores a computer program executed by the processor.

[0020] The control device 8 has the function of controlling the operation of the irrigation device 6, and is capable of controlling, for example, the amount of liquid delivered per unit time, the duration and timing of delivery of liquid, etc.

[0021] The control device 8 is further connected to a plurality of flow rate sensors 10, 12. The control device 8 receives measured values ​​transmitted from each of the flow rate sensors 10, 12, and controls the operation of the irrigation device 6 based on the measured values.

[0022] The flow velocity sensors 10 and 12 are sensors for measuring the flow velocity of a fluid flowing through a measurement object. The flow velocity sensors 10 and 12 may be any type of flow velocity sensor as long as they can measure the flow velocity of a fluid flowing through a measurement object. In the first embodiment, a contact-type heat pulse flow velocity sensor is used.

[0023] Each of the heat pulse flow sensors 10 and 12 has one heater and two resistance thermometers. The first resistance thermometer, which is closer to the heater (= D1), is positioned upstream in the flow direction, while the second resistance thermometer, which is farther from the heater (= D2 > D1), is positioned downstream in the flow direction. The sensor's mounting surface is then brought into contact with the surface of the object being measured, and a constant pulse current is applied to the heater to generate heat. The heat generated by the heater is transferred to the two resistance thermometers via the substrate. Initially, the first resistance thermometer, which is closer to the heater, increases in temperature faster than the second resistance thermometer. However, as the fluid flows inside the object being measured, heat is transferred in the direction of flow, causing the second resistance thermometer to increase in temperature at a relatively higher rate. After that, the temperatures of the two resistance thermometers become equal.

[0024] If the time from when the current is input to the heater until the temperatures of the pair of resistance thermometers become equal is defined as t0, the flow velocity F of the fluid is calculated based on the following formula 1: F=c(D1+D2) / (2×t0)

[0025] c is a constant obtained by calibration. In addition to calibration, c can also be obtained by simulating the temperature distribution.

[0026] 1 , the flow rate sensors 10 and 12 are installed in different locations. In the first embodiment, the flow rate sensor 10 is installed in the liquid supply unit 7 of the irrigation device 6, and the flow rate sensor 12 is installed in the stem 16 of the plant 4. The flow rate sensor 10 measures the flow rate of water flowing through the liquid supply unit 7 of the irrigation device 6, and the flow rate sensor 12 measures the flow rate of sap flowing through the stem 16 of the plant 4.

[0027] The plant 4 shown in Fig. 1 has a plurality of stems 16, a plurality of leaves 18, and a fruit 20. In the first embodiment, the plant 4 is a strawberry plant, and the fruit 20 is a strawberry. Fig. 1 shows only one fruit 20. In the strawberry-like plant 4, the stem 16 leading to the leaves 18 and the stem 16 leading to the fruit 20 are separated from the base.

[0028] 1 is installed on a stem 16A, which is connected to a leaf 18A, among a plurality of stems 16. No fruit 20 is connected to the stem 16A, only the leaf 18A is connected to it. By installing the flow velocity sensor 12 on the stem 16A, it is possible to measure the flow velocity of sap (water used for photosynthesis in the leaf 18A) flowing from the base of the plant 4 toward the leaf 18A.

[0029] The irrigation system 2 having the above configuration controls the operation of the irrigation device 6 based on the correlation between the measurement value of the flow rate sensor 10 (the flow rate of water passed through the water supply unit 7) and the measurement value of the flow rate sensor 12 (the flow rate of sap flowing toward the leaves 18A). This allows irrigation that is more suited to the state of the plant 4 using a simple configuration. The algorithm for executing this control will be described using Figure 2.

[0030] FIG. 2 is a diagram showing an algorithm relating to a method for controlling the operation of the irrigation device 6 in the irrigation system 2 of the first embodiment.

[0031] 2 includes a number of graphs, each of which shows time [min] on the horizontal axis and flow rate per unit time [ml / min] on the vertical axis.

[0032] As indicated by "Start Irrigation" on the left side of Fig. 2, the control device 8 first starts irrigation by the irrigation device 6. The initial amount of irrigation by the irrigation device 6 may be a predetermined amount. In the example shown in Fig. 2, the initial amount of irrigation is set to irrigation by the irrigation device 6 for 5 seconds.

[0033] In the example shown in FIG. 2, two graphs (Graph 1 and Graph 2) are shown, each showing a different pattern of change in flow rate after the start of irrigation.

[0034] In graph 1, after the start of irrigation, the measurement value of flow velocity sensor 10 changes, and then, after a further time, the measurement value of flow velocity sensor 12 changes. The integrated value of the measurement values ​​of flow velocity sensor 10 is S1a, and the integrated value of the measurement values ​​of flow velocity sensor 12 is S1b.

[0035] In graph 2, the measurement value of flow velocity sensor 10 changes after irrigation starts, but the measurement value of flow velocity sensor 12 thereafter hardly changes.

[0036] The control device 8 calculates the ratio of S1b to S1a (S1b / S1a) and compares it with a predetermined threshold value CL. The control device 8 determines the next amount of irrigation water to be supplied to the irrigation device 6 based on the comparison result.

[0037] As shown in Graph 1, when S1b / S1a is equal to or greater than CL (S1b / S1a≧CL), the control device 8 increases the next amount of irrigation water from the irrigation device 6 compared to the previous amount of irrigation water. In the example shown in the following Graphs 3 and 4, the next amount of irrigation water is increased by continuing irrigation by the irrigation device 6 for 10 seconds, which is longer than the previous 5 seconds.

[0038] As shown in graph 2, when S1b / S1a is less than CL (S1b / S1a<CL), the control device 8 stops the next irrigation by the irrigation device 6.

[0039] In graphs 3 and 4, where the amount of irrigation water was increased, the measurement value of flow velocity sensor 10 changes after a time interval following the second irrigation, and then the measurement value of flow velocity sensor 12 changes after a further time interval. Regarding this change in measurement value, the integrated value of the measurement values ​​of flow velocity sensor 10 is designated as S2a, and the integrated value of the measurement values ​​of flow velocity sensor 12 is designated as S2b.

[0040] The control device 8 calculates the ratio of S2b to S2a (S2b / S2a), compares it with a predetermined threshold value CL, and determines the next amount of irrigation to be performed by the irrigation device 6 based on the comparison result. The threshold value CL used here may be the same as the threshold value CL used in the first determination, or may be a different value. In the example shown in FIG. 2, the same value was used for the threshold value CL.

[0041] As shown in graph 3, when S2b / S2a≧CL, the control device 8 increases the next amount of irrigation water from the irrigation device 6 compared to the previous amount of irrigation water. Specifically, as shown in graph 5, the next amount of irrigation water is increased by continuing irrigation by the irrigation device 6 for 15 seconds, which is longer than the previous 10 seconds.

[0042] In graph 5, since the correlation between the integrated values ​​of the measurement values ​​of the flow rate sensors 10 and 12 detected after the third irrigation is S3b / S3a≧CL, the amount of irrigation for the fourth time is further increased (not shown).

[0043] As shown in graph 4, when S2b / S2a<CL, the control device 8 reduces the amount of water to be irrigated next time by the irrigation device 6 compared to the amount of water to be irrigated the previous time. Specifically, as shown in graph 6, the amount of water to be irrigated next time is reduced by continuing irrigation by the irrigation device 6 for 5 seconds, which is shorter than the previous 10 seconds.

[0044] In graph 6, since the correlation between the integrated values ​​of the measurement values ​​of the flow rate sensors 10 and 12 detected after the third irrigation is S3b / S3a<CL, the fourth irrigation is canceled.

[0045] As described above, the next irrigation amount by the irrigation device 6 is determined based on the correlation (S1b / S1a, S2b / S2a, S3b / S3a) between the measurement values ​​S1a, S2a, and S3a of the flow velocity sensor 10 and the measurement values ​​S1b, S2b, and S3b of the flow velocity sensor 12.

[0046] The measured values ​​S1a, S2a, and S3a of the flow rate sensor 10 indicate the flow rate of water flowing through the liquid delivery unit 7 of the irrigation device 6, and the measured values ​​S1b, S2b, and S3b of the flow rate sensor 12 indicate the flow rate of sap flowing in the stem 16A connected to the leaf 18A of the plant 4. When S1b / S1a, S2b / S2a, and S3b / S3a are equal to or greater than a predetermined threshold value CL, it can be diagnosed that the flow rate of sap flowing toward the leaf 18A is relatively high and that photosynthesis is actively occurring in the leaf 18A of the plant 4. In such a case, by increasing the amount of water irrigated by the irrigation device 6, the flow rate of sap flowing toward the leaf 18A can be increased, promoting photosynthesis in the leaf 18A and facilitating the growth of the plant 4.

[0047] It is to be noted that the amount of irrigation water need not necessarily be increased, and the previous amount of irrigation water may also be maintained.

[0048] On the other hand, if S1b / S1a, S2b / S2a, and S3b / S3a are less than the predetermined threshold value CL, it can be diagnosed that the flow rate of sap flowing toward the leaf 18A is low and that photosynthesis is not actively taking place in the leaf 18A of the plant 4. In such a case, by reducing / stopping irrigation by the irrigation device 6, the amount of water supplied to the plant 4 can be reduced, and excess water can be prevented from being supplied to the plant 4.

[0049] As described above, when S1b / S1a, S2b / S2a, and S3b / S3a are less than a predetermined threshold value CL, the operation of the irrigation device 6 can be controlled so that the amount of water delivered by the irrigation device 6 is relatively smaller than when S1b / S1a, S2b / S2a, and S3b / S3a are equal to or greater than the predetermined threshold value CL.

[0050] According to the irrigation system 2 of embodiment 1, irrigation that is more suitable for the state of the plants 4 can be performed using a simple configuration consisting of the irrigation device 6 and two flow rate sensors 10 and 12.

[0051] FIG. 3 shows the results of an experiment in which the irrigation system 2 shown in FIG. 1 was operated based on the algorithm shown in FIG. 2 and the plant 4 was irrigated twice.

[0052] In FIG. 3, the horizontal axis represents time [min] and the vertical axis represents flow velocity [min / sec].

[0053] As shown in Figure 3, the first irrigation is performed by the irrigation device 6 with a predetermined amount. Within about 5 minutes, the measurement value of the flow velocity sensor 10 showed a change (corresponding to S1a). After that, the measurement value of the flow velocity sensor 12 showed a change (corresponding to S1b).

[0054] 3, since S1b / S1a≧CL, the amount of watering was increased for the second time. Within about 5 minutes, the measurement value of flow velocity sensor 10 showed a change (corresponding to S2a), and after a further delay, the measurement value of flow velocity sensor 12 showed a change (corresponding to S2b).

[0055] The measurement value S2b of the flow velocity sensor 12 taken after the second irrigation was significantly increased compared to the measurement value S1b of the flow velocity sensor 12 taken after the first irrigation. This shows that by increasing the amount of water taken in the second irrigation when it is assumed that photosynthesis is actively taking place in the leaf 18A, the flow rate of the sap flowing toward the leaf 18A can be significantly increased.

[0056] The irrigation system 2 particularly uses contact-type heat pulse flow rate sensors 10, 12. Because the flow rate sensors 10, 12 can be manufactured inexpensively, compactly, and with low heat capacity, it is easy to install multiple sensors, and the irrigation system 2 shown in Figure 1 can be easily constructed.

[0057] By installing at least two flow rate sensors 10, 12 in the irrigation system 2, the effectiveness of the irrigation can be confirmed by checking the correlation between the timing and amount of irrigation using the irrigation device 6 and the presence or absence and amount of water absorption by the plants 4 thereafter. This allows the timing and amount of the next irrigation to be determined, thereby ensuring the minimum amount of irrigation required. This makes it possible to prevent diseases caused by excessive watering and to detect diseases caused by other reasons. Such an irrigation system 2 can be used for irrigation management in agriculture, such as open-field cultivation, greenhouses, and plant factories, as well as for growing ornamental plants such as flowers and foliage plants, and for growing plants for biofuel.

[0058] (Another example of embodiment 1) In an irrigation system 2 having the same configuration as embodiment 1, the plant 4 was changed from strawberry to sweet potato, and flow velocity sensors 12 were attached to the stems of seedlings grown normally and seedlings that had been given excessive fertilizer and had shriveled leaves, each of which had approximately the same diameter, and the results of irrigation using the irrigation device 6 were compared.

[0059] As a result, the flow rate of the sap flowing through the stem 16A connected to the leaf 18A of sweet potato was also observed using the flow rate sensor 12. For rooted plants 4, such as sweet potato, it is often impossible to monitor their growth status from above ground. However, by using an algorithm similar to that shown in Figure 2, irrigation can be optimized and the root volume required for water absorption can be calculated from the ratio of the sap flow rate to the sap flow rate per unit time. In fact, the ratio of the sap flow rate to the sap flow rate per unit time for the two seedlings mentioned above was twice as high. When the seedlings were dug up and inspected, the root volume, i.e., the number of sweet potatoes harvested, was approximately twice as high. Thus, the irrigation system 2 is expected to be effective in monitoring the growth status of plants 4 during the process, making it particularly useful for irrigation management during seedling cultivation. Using this, when the ratio of the measurement value of flow velocity sensor 12 (second flow velocity sensor) to the measurement value of flow velocity sensor 10 (first flow velocity sensor) reaches or exceeds a predetermined ratio, the volume of the roots of plant 4 may be calculated relatively, and whether or not to harvest plant 4 may be determined based on the calculated volume. This makes it possible to ensure a stable harvest of plant 4, such as sweet potato.

[0060] (Comparative Example of First Embodiment) Instead of installing flow rate sensor 10 in liquid delivery unit 7 as in the first embodiment, a soil sensor was installed in soil 9, and another flow rate sensor was also installed in stem 16B connected to fruit 20. The soil sensor is capable of measuring the amount of moisture. In this configuration, irrigation was performed using irrigation device 6, and the measurements of the soil sensor, flow rate sensor 12 (the amount of sap flowing into leaves 18A, which is thought to roughly correspond to the amount of transpiration), and the measurement of the other flow rate sensor (the amount of sap flowing into fruit 20, which is thought to roughly correspond to the amount of translocation).

[0061] Although the moisture content measured by the soil sensor tended to change gradually, no sudden changes were observed that corresponded to the hourly changes in each flow rate as shown in Figure 3. Therefore, it was found that it was difficult to obtain a correlation between the moisture content of the soil 9 and the timing of transpiration and translocation of the plant 4. ２ Measurements were also taken using sensors, temperature sensors, and humidity sensors, but a simple and effective algorithm like that shown in Figure 2 could not be found to determine the timing and amount of watering.

[0062] (Actions and effects of embodiment 1) As described above, the irrigation system 2 of embodiment 1 comprises an irrigation device 6 that supplies water to the plants 4, a control device 8 that controls the operation of the irrigation device 6, and a flow rate sensor 10 (first flow rate sensor) and a flow rate sensor 12 (second flow rate sensor) that are installed at different positions so as to measure the flow rate of the sap flowing through the plants 4 or the flow rate of water flowing through the irrigation device 6, and the control device 8 controls the operation of the irrigation device 6 based on the correlation between the measurement values ​​of the flow rate sensor 10 and the measurement values ​​of the flow rate sensor 12.

[0063] With this configuration, by controlling the operation of the irrigation device 6 based on the correlation between the measurements of the two flow velocity sensors 10, 12, irrigation control that promotes the growth of the plants 4 can be performed with a simple configuration.

[0064] In addition, in the irrigation system 2 of embodiment 1, the flow rate sensor 10 (first flow rate sensor) is installed in the liquid delivery section 7 of the irrigation device 6, and the flow rate sensor 12 (second flow rate sensor) is installed in the stem 16A connected to the leaf 18A of the plant 4, and measures the flow rate of the sap flowing toward the leaf 18A.

[0065] With this configuration, by controlling the operation of the irrigation device 6 based on the correlation between the flow rate of water flowing through the irrigation device 6 and the flow rate of sap flowing through the plant 4, it is possible to perform irrigation control that promotes the growth of the plant 4, such as determining the amount and timing of water delivery from the irrigation device 6 so as to increase the flow rate of sap flowing toward the leaves 18A of the plant 4.

[0066] Furthermore, in the irrigation system 2 according to the first embodiment, the control device 8 determines the amount of water delivered by the irrigation device 6 depending on whether the ratio (S1b / S1a, S2b / S2a, S3b / S3a) of the measurement value of the flow rate sensor 12 (second flow rate sensor) to the measurement value of the flow rate sensor 10 (first flow rate sensor) is equal to or greater than a predetermined threshold value CL (predetermined ratio). With this configuration, it is possible to perform irrigation control that promotes the growth of the plant 4, for example, by controlling the amount of water delivered by the irrigation device 6 so as to increase the flow rate of sap flowing toward the leaves 18A of the plant 4.

[0067] Furthermore, in the irrigation system 2 according to the first embodiment, when the ratios of the measured values ​​(S1b / S1a, S2b / S2a, S3b / S3a) are not equal to or greater than a predetermined threshold value CL (predetermined ratio), the control device 8 controls the amount of water sent by the irrigation device 6 to be relatively smaller than when the ratio of the measured values ​​is equal to or greater than the predetermined threshold value CL. With this configuration, for example, when the flow rate of sap flowing toward the leaves 18A of the plant 4 is low, irrigation control can be performed according to the state of the plant 4, such as reducing or stopping the amount of water sent by the irrigation device 6.

[0068] Furthermore, in the irrigation system 2 according to the first embodiment, the control device 8 controls the operation of the irrigation device 6 based on the correlation between the integrated value of the measurement values ​​of the flow velocity sensor 10 (first flow velocity sensor) and the integrated value of the measurement values ​​of the flow velocity sensor 12 (second flow velocity sensor). With this configuration, by controlling the irrigation device 6 based on the correlation between the integrated values ​​(i.e., flow rates) of the measurement values ​​of the two flow velocity sensors 10 and 12, it is possible to accurately control irrigation to promote the growth of the plants 4.

[0069] The irrigation method of embodiment 1 is a method for controlling the operation of an irrigation device 6 that supplies water to a plant 4, and controls the operation of the irrigation device 6 based on the correlation between the measured values ​​of a flow rate sensor 10 (first flow rate sensor) and a flow rate sensor 12 (second flow rate sensor), which are installed at different positions to measure the flow rate of sap flowing through the plant 4 or the flow rate of water flowing through the irrigation device 6.

[0070] According to this method, irrigation control that promotes the growth of the plants 4 can be carried out with a simple configuration.

[0071] (Variant of embodiment 1) In embodiment 1, the control device 8 controls (outputs) the operation of the irrigation device 6 based on the measurement values ​​(inputs) of the flow rate sensors 10 and 12, but this is not limited to this case.

[0072] FIG. 4 is a diagram showing an irrigation system 100 according to a modified example of the first embodiment.

[0073] The irrigation system 100 shown in FIG. 4 differs from the irrigation system 2 of embodiment 1 in that it has a server 102 instead of the control device 8 and performs various processes on the server 102.

[0074] The irrigation system 100 additionally includes a server 102, a measurement circuit 104, and wireless units 106 and 108.

[0075] The server 102 is a component that performs processing related to the control of the irrigation system 100, and any type of server such as a cloud server may be used. The server 102 communicates with the wireless units 106 and 108 of the irrigation system 100.

[0076] The measurement circuit 104 is a circuit for outputting the measurement values ​​of the flow velocity sensors 10 and 12. The measurement circuit 104 is connected to each of the two flow velocity sensors 10 and 12. The measurement circuit 104 may be any type of circuit as long as it is capable of outputting the measurement values ​​of the flow velocity sensors 10 and 12.

[0077] The wireless units 106, 108 are components for communicating with the server 102. The wireless unit 106 is provided in the irrigation device 6, and the wireless unit 108 is provided in the measurement circuit 104. The wireless unit 106 provided in the irrigation device 6 receives a control signal for controlling the irrigation device 6 from the server 102. The wireless unit 108 provided in the measurement circuit 104 transmits the measurement values ​​of the flow velocity sensors 10, 12 output from the measurement circuit 104 to the server 102.

[0078] The wireless units 106 and 108 may be any type of component that can communicate with the server 102 .

[0079] In the irrigation system 100 having the above configuration, the server 102 receives the measurement values ​​(input) of each of the flow velocity sensors 10, 12 transmitted from the wireless unit 108, determines the amount of irrigation to be performed by the irrigation device 6 based on the measurement values, and transmits a control signal (output) to the wireless unit 106 to cause the irrigation device 6 to irrigate at the determined amount of irrigation. This makes it possible to control the irrigation device 6 using an algorithm similar to that of the irrigation system 2 of embodiment 1, and to perform irrigation that is more suited to the state of the plants 4 using a simple configuration.

[0080] The server 102 has a program for executing the algorithm shown in Fig. 2. When the program is executed by the processor, it causes the irrigation device 6 to operate in a desired manner. The irrigation system 100 shown in Fig. 4 has a computer-readable medium that stores the program.

[0081] (Actions and effects of the modified example of embodiment 1) The irrigation system 100 relating to the modified example has a program for controlling the operation of the irrigation device 6 that supplies water to the plants 4, and when the program is executed by a processor, it causes the processor to control the operation of the irrigation device 6 based on the correlation between the measured values ​​of the flow rate sensor 10 (first flow rate sensor) and the flow rate sensor 12 (second flow rate sensor), which are installed at different positions so as to measure the flow rate of the sap flowing through the plants 4 or the flow rate of water flowing through the irrigation device 6.

[0082] According to this configuration, irrigation control that promotes the growth of the plants 4 can be performed with a simple configuration.

[0083] Similarly, the irrigation system 100 of the modified example has a computer-readable medium storing a program for controlling the operation of the irrigation device 6 that supplies water to the plants 4, and when the program is executed by a processor, the processor controls the operation of the irrigation device 6 based on the correlation between the measured values ​​of the flow rate sensor 10 (first flow rate sensor) and the flow rate sensor 12 (second flow rate sensor), which are installed at different positions to measure the flow rate of sap flowing through the plants 4 or the flow rate of water flowing through the irrigation device 6.

[0084] According to this configuration, irrigation control that promotes the growth of the plants 4 can be performed with a simple configuration.

[0085] (Embodiment 2) An irrigation system according to embodiment 2 will be described with reference to Figures 5 and 6. Descriptions that overlap with embodiment 1 will be omitted as appropriate.

[0086] FIG. 5 is a schematic diagram showing an irrigation system 200 according to the second embodiment.

[0087] The irrigation system 200 shown in FIG. 5 differs from the irrigation system 2 of the first embodiment in that it targets a plant 204 that is different from the plant 4 shown in FIG.

[0088] The plant 204 has a plurality of stems 216, a plurality of leaves 218, and a fruit 220. In the second embodiment, the plant 204 is an apple tree, and the fruit 220 is an apple.

[0089] In the case of an apple-like plant 204, unlike the strawberry of embodiment 1, a stem 216A connected to a leaf 218 and a stem 216B connected to a fruit 220 branch off from the same stem 216C. Therefore, when measuring the flow rate of the sap flowing toward the leaf 218 and the flow rate of the sap flowing toward the fruit 220, flow rate sensors can be attached to the stems 216A and 216B, rather than to the stem 216C.

[0090] The irrigation system 200 shown in FIG. 5 includes an irrigation device 6, a control device 8, a flow rate sensor 10, and two flow rate sensors 212 and 214.

[0091] Flow sensor 212 is located on stem 216A leading to leaf 218, and flow sensor 214 is located on stem 216B leading to fruit 220.

[0092] By installing flow velocity sensor 212 on stem 216A, it is possible to measure the flow velocity of sap flowing toward leaf 218. By installing flow velocity sensor 214 on stem 216B, it is possible to measure the flow velocity of sap flowing toward fruit 220 (which may be considered as translocation).

[0093] The irrigation system 200 having the above configuration controls the operation of the irrigation device 6 based on the correlation between the measurement value of the flow velocity sensor 212 (the flow velocity of the sap flowing toward the leaves 218) and the measurement value of the flow velocity sensor 214 (the flow velocity of the sap flowing toward the fruits 220). The algorithm for executing this control will be described with reference to FIG. 6.

[0094] FIG. 6 is a diagram showing an algorithm relating to a method for controlling the operation of the irrigation device 6 in the irrigation system 200 of the second embodiment.

[0095] FIG. 6 includes a number of graphs, each of which shows time [min] on the horizontal axis and flow rate per unit time [ml / min] on the vertical axis.

[0096] The algorithm shown in Figure 6, like the algorithm shown in Figure 2, controls the amount of irrigation water to be supplied by the irrigation device 6 based on the correlation (S1c / S1b, S2c / S2b, S3c / S3b) between the measurement values ​​(accumulated values) S1b, S2b, and S3b of the flow velocity sensor 212 and the measurement values ​​(accumulated values) S1c, S2c, and S3c of the flow velocity sensor 214.

[0097] More specifically, if S1c / S1b, S2c / S2b, and S3c / S3b are equal to or greater than a predetermined threshold value CL, the amount of irrigation by the irrigation device 6 is increased and maintained, and if they are less than the threshold value CL, the amount of irrigation by the irrigation device 6 is reduced or stopped.

[0098] When S1c / S1b, S2c / S2b, and S3c / S3b are equal to or greater than a predetermined threshold value CL, it can be diagnosed that the amount of sap flowing toward the fruit 220 is relatively large, and that a large amount of nutrients produced by photosynthesis in the leaves 218 is being translocated to the fruit 220, causing the fruit 220 to grow. In such a case, by increasing the amount of irrigation by the irrigation device 6, the amount of sap flowing toward the leaves 218 and the amount of sap flow (translocation) flowing toward the fruit 220 can be increased, thereby promoting the growth of the fruit 220.

[0099] On the other hand, if S1c / S1b, S2c / S2b, and S3c / S3b are less than a predetermined threshold value CL, it can be diagnosed that the flow rate of sap flowing toward the fruit 220 is low, that nutrients produced by photosynthesis in the leaves 218 are not being transferred to the fruit 220 very much, and that the growth of the fruit 220 is not progressing well. In such a case, by reducing / stopping irrigation by the irrigation device 6, the amount of water supplied to the plant 4 can be reduced, and excess water can be prevented from being supplied to the plant 4.

[0100] In this way, irrigation that is more suited to the condition of the plant 204 can be performed using a simple configuration consisting of the irrigation device 6 and two flow rate sensors 212, 214.

[0101] The configuration and algorithm of the first embodiment may be combined with the configuration and algorithm of the second embodiment. That is, three flow velocity sensors 10, 212, and 214 may be installed, and the next irrigation amount may be determined based on first information indicating whether S1b / S1a, S2b / S2a, and S3b / S3a are equal to or greater than a predetermined threshold value CL, as in the first embodiment, and second information indicating whether S1c / S1b, S2c / S2b, and S3c / S3b are equal to or greater than a predetermined threshold value CL, as in the second embodiment. This method can be applied not only to plants 204 such as apples, but also to plants 4 such as strawberries. The results of this example are shown in FIG. 7 .

[0102] Figure 7 is a graph showing the flow rate measurement results when three flow rate sensors 10, 212, and 214 were installed and irrigation was repeated multiple times using the irrigation device 6 using both the algorithm shown in Figure 1 and the algorithm shown in Figure 6.

[0103] In Figure 7, the measurement results of the flow velocity sensor 10 installed in the liquid delivery section 7 are shown as "liquid delivery flow," the measurement results of the flow velocity sensor 212 installed in the stem 216A connected to the leaf 218 are shown as "sap flow," and the measurement results of the flow velocity sensor 214 installed in the stem 216B connected to the fruit 220 are shown as "transfer flow."

[0104] As shown in Figure 7, thresholds were set for the ratio of the sap flow rate to the supply flow rate and the ratio of the diversion flow rate to the sap flow rate, and the amount of water irrigated by the irrigation device 6 was increased or decreased depending on whether each ratio was equal to or greater than the threshold. This allowed the apple fruit 220 to be irrigated at the appropriate time by appropriate watering, and it was possible to confirm the state of transpiration (corresponding to "sap flow"), which is thought to be photosynthesis, and the state that is thought to be the subsequent diversion.

[0105] As described above, the irrigation system 200 can grasp the timing and extent of a phenomenon considered to be transpiration by measuring the sap flow to the leaves 218. Furthermore, by measuring the sap flow from the opposite leaves 218 or the sap flow to the fruit 220, the timing and extent of a phenomenon considered to be translocation can be grasped. By comparing the correlation between the sap flow to the leaves 218 and the sap flow to the fruit 220 and, based on the comparison results, determining whether translocation was confirmed after transpiration, the timing and amount of irrigation can be determined, thereby maximizing translocation and achieving highly efficient growth of the buds and fruit 220. Furthermore, by suppressing the accumulation of unnecessary transpiration and translocation, excessive moisture can be prevented and the harvest time can be accurately determined.

[0106] It should be noted that the flow rate of sap flowing to the flower may be measured by installing a flow rate sensor on the stem leading to the flower, not just when measuring the sap flow to the fruit 220. That is, a flow rate sensor may be installed on the stem leading to the fruit 220 or the flower to measure the flow rate of sap flowing to the fruit 220 or the flower.

[0107] (Actions and effects of embodiment 2) As described above, the irrigation system 200 of embodiment 2 comprises an irrigation device 6 that supplies water to the plant 204, a control device 8 that controls the operation of the irrigation device 6, and a flow velocity sensor 212 (first flow velocity sensor) and a flow velocity sensor 214 (second flow velocity sensor) that are installed at different positions so as to measure the flow velocity of the sap flowing through the plant 204, and the control device 8 controls the operation of the irrigation device 6 based on the correlation between the measurement values ​​of the flow velocity sensor 212 and the measurement values ​​of the flow velocity sensor 214.

[0108] With this configuration, by controlling the operation of the irrigation device 6 based on the correlation between the measurements of the two flow velocity sensors 212, 214, irrigation control that promotes the growth of the plant 204 can be performed with a simple configuration.

[0109] In addition, in the irrigation system 200 of embodiment 2, the flow rate sensor 212 (first flow rate sensor) is installed on the stem 216A connected to the leaf 218 of the plant 204 and measures the flow rate of the sap flowing toward the leaf 218, and the flow rate sensor 214 (second flow rate sensor) is installed on the stem 216B connected to the fruit 220 of the plant 204 and measures the flow rate of the sap flowing toward the fruit 220.

[0110] With this configuration, by controlling the operation of the irrigation device 6 based on the correlation between the flow rate of the sap flowing toward the leaves 218 and the flow rate of the sap flow (translocation) flowing toward the fruit 220, it is possible to perform irrigation control that promotes the growth of the plant 204, such as determining the amount and timing of water delivery from the irrigation device 6 so as to increase the flow rate of the sap flowing toward the fruit 220.

[0111] Furthermore, in the irrigation system 200 according to the second embodiment, the control device 8 determines the amount of water delivered by the irrigation device 6 depending on whether the ratio (S1c / S1b, S2c / S2b, S3c / S3b) of the measurement value of the flow rate sensor 214 (second flow rate sensor) to the measurement value of the flow rate sensor 212 (first flow rate sensor) is equal to or greater than a predetermined threshold value CL (predetermined ratio). With this configuration, it is possible to perform irrigation control that promotes the growth of the plant 204, for example, by controlling the amount of water delivered by the irrigation device 6 so as to increase the flow rate of sap flowing toward the fruit 220 of the plant 204.

[0112] Furthermore, in the irrigation system 200 according to the second embodiment, when the ratios of the measured values ​​(S1c / S1b, S2c / S2b, S3c / S3b) are not equal to or greater than a predetermined threshold value CL (predetermined ratio), the control device 8 controls the amount of water sent by the irrigation device 6 to be relatively smaller than when the ratio of the measured values ​​is equal to or greater than the predetermined threshold value CL. With this configuration, for example, when the flow rate of sap flowing toward the fruit 220 of the plant 204 is low, irrigation control can be performed according to the state of the plant 204, such as reducing or stopping the amount of water sent by the irrigation device 6.

[0113] Furthermore, in the irrigation system 200 according to the second embodiment, the control device 8 controls the operation of the irrigation device 6 based on the correlation between the integrated value of the measurement values ​​of the flow velocity sensor 212 (first flow velocity sensor) and the integrated value of the measurement values ​​of the flow velocity sensor 214 (second flow velocity sensor). With this configuration, by controlling the irrigation device 6 based on the correlation between the integrated values ​​(i.e., flow rates) of the measurement values ​​of the two flow velocity sensors 212, 214, it is possible to accurately control irrigation to promote the growth of the plant 204.

[0114] The irrigation method of embodiment 2 is a method for controlling the operation of an irrigation device 6 that supplies water to a plant 204, and controls the operation of the irrigation device 6 based on the correlation between the measured values ​​of a flow velocity sensor 212 (first flow velocity sensor) and a flow velocity sensor 214 (second flow velocity sensor), which are installed at different positions to measure the flow velocity of the sap flowing through the plant 204.

[0115] According to this method, irrigation control that promotes the growth of the plant 204 can be performed with a simple configuration.

[0116] (Embodiment 3) An irrigation system according to embodiment 3 will be described with reference to Figures 8 and 9. Descriptions that overlap with embodiments 1 and 2 will be omitted as appropriate.

[0117] FIG. 8 is a schematic diagram showing an irrigation system 300 according to the third embodiment.

[0118] The irrigation system 300 shown in FIG. 8 differs from the irrigation systems 2 of the first and second embodiments in that the irrigation system 300 targets a plant 304 that is different from the plant 4 shown in FIG. 1 and the plant 204 shown in FIG.

[0119] The plant 304 has a plurality of stems 316, a plurality of leaves 318, and a fruit 320. In the third embodiment, the plant 304 is a tomato plant, and the fruit 320 is a tomato.

[0120] In the case of a plant 304 such as a tomato, similarly to the apple or the like in embodiment 2, stem 316A connected to leaf 318A, stem 316B connected to leaf 318B, and stem 316C connected to fruit 320 are branched off from another stem 316D. Thus, when measuring the flow rate of sap flowing toward leaf 318 and the flow rate of sap flowing toward fruit 320, flow rate sensors can be attached to stems 316A, 316B, and 316C, rather than stem 316D.

[0121] The irrigation system 300 shown in FIG. 8 includes an irrigation device 6, a control device 8, a flow rate sensor 10, and three flow rate sensors 312, 313, and 314.

[0122] Flow velocity sensor 312 is installed on stem 316A connected to lower leaf 318A, flow velocity sensor 313 is installed on stem 316B connected to upper leaf 318B, and flow velocity sensor 314 is installed on stem 316C connected to fruit 320.

[0123] By installing flow velocity sensor 312 on stem 316A, it is possible to measure the flow velocity of the sap flowing toward leaf 318A. By installing flow velocity sensor 313 on stem 316B, it is possible to measure the flow velocity of the sap flowing toward leaf 318A. By installing flow velocity sensor 314 on stem 316C, it is possible to measure the flow velocity of the sap flowing toward fruit 320.

[0124] As shown in FIG. 8, two flow rate sensors 312 and 313 are provided to measure the flow rate of the sap flowing toward the leaves 318, with the flow rate sensor 312 being positioned below and the flow rate sensor 313 being positioned below.

[0125] In the case of a plant 304 such as a tomato, it is desirable to minimize the flow rate of the sap flowing at the top while ensuring a certain level of flow rate of the sap flowing at the bottom in order to increase the sugar content. Therefore, the irrigation system 300 controls the operation of the irrigation device 6 based on the correlation between the measurement value of the flow rate sensor 312 disposed below (the flow rate of the sap flowing toward the leaf 318A) and the measurement value of the flow rate sensor 323 (the flow rate of the sap flowing toward the leaf 318B). The algorithm for executing this control will be described using FIG. 9.

[0126] FIG. 9 is a diagram showing an algorithm relating to a method for controlling the operation of the irrigation device 6 in the irrigation system 300 of the third embodiment.

[0127] FIG. 9 includes a plurality of graphs, each of which shows time [min] on the horizontal axis and flow rate per unit time [ml / min] on the vertical axis.

[0128] The algorithm shown in Figure 9, like the algorithm shown in Figure 6, controls the amount of irrigation by the irrigation device 6 based on the correlation (S1b' / S1b, S2b' / S2b, S3b' / S3b) between the measurement values ​​(accumulated values) S1b, S2b, and S3b of the flow velocity sensor 312 and the measurement values ​​(accumulated values) S1b', S2b', and S3b' of the flow velocity sensor 313.

[0129] More specifically, if S1b' / S1b, S2b' / S2b, and S3b' / S3b are less than a predetermined threshold value CL, irrigation by the irrigation device 6 is maintained, and if they are equal to or greater than the threshold value CL, irrigation by the irrigation device 6 is stopped.

[0130] When S1b' / S1b, S2b' / S2b, and S3b' / S3b are less than a predetermined threshold value CL, it can be diagnosed that the amount of sap flowing toward the upper leaves 318B is relatively small, and that the sugar content of the fruit 320 is likely to increase. In such a case, by maintaining the amount of water irrigation by the irrigation device 6, the sugar content of the fruit 320 can be increased and growth can be promoted.

[0131] On the other hand, when S1b' / S1b, S2b' / S2b, and S3b' / S3b are equal to or greater than the predetermined threshold value CL, it can be diagnosed that the amount of sap flowing toward the upper leaves 318B is relatively large, making it difficult to increase the sugar content of the fruit 320. In such a case, the decrease in sugar content of the fruit 320 can be prevented by stopping irrigation by the irrigation device 6.

[0132] In this way, irrigation that is more suited to the state of the plant 304 can be performed using a simple configuration consisting of the irrigation device 6 and flow rate sensors 312, 314.

[0133] In addition to the flow rate sensors 312 and 313, the irrigation system 300 of the third embodiment is provided with a flow rate sensor 10 that measures the flow rate of water flowing through the liquid delivery section 7 of the irrigation device 6, and a flow rate sensor 314 that measures the flow rate of sap flowing through the stem 316C connected to the fruit 320. Therefore, it is possible to further combine and execute the algorithm of the first embodiment and the algorithm of the second embodiment.

[0134] (Actions and Effects) As described above, the irrigation system 300 of embodiment 3 comprises an irrigation device 6 that supplies water to the plant 304, a control device 8 that controls the operation of the irrigation device 6, and a flow velocity sensor 312 (first flow velocity sensor) and a flow velocity sensor 313 (second flow velocity sensor) that are installed at different positions so as to measure the flow velocity of the sap flowing through the plant 304, and the control device 8 controls the operation of the irrigation device 6 based on the correlation between the measurement values ​​of the flow velocity sensor 312 and the measurement values ​​of the flow velocity sensor 313.

[0135] With this configuration, the operation of the irrigation device 6 can be controlled based on the correlation between the measurements of the two flow velocity sensors 312, 313, thereby enabling irrigation control that promotes the growth of the plant 304 to be performed with a simple configuration.

[0136] In addition, in the irrigation system 300 of embodiment 3, the flow velocity sensor 312 (first flow velocity sensor) is installed on the stem 316A connected to the leaf 318A of the plant 304, and the flow velocity sensor 313 (second flow velocity sensor) is installed at a higher position than the flow velocity sensor 312 on the stem 316B connected to the leaf 318B of the plant 304.

[0137] With this configuration, the operation of the irrigation device 6 can be controlled based on the correlation between the flow rate of the sap flowing through the upper part and the flow rate of the sap flowing through the lower part, thereby enabling irrigation control to be performed that promotes the growth of the plant 304, such as determining the amount and timing of water delivery from the irrigation device 6 so as to reduce the flow rate of the sap flowing through the upper part in order to increase the sugar content of the plant 304, such as a tomato.

[0138] Furthermore, in the irrigation system 300 according to the third embodiment, the control device 8 determines the amount of water delivered by the irrigation device 6 depending on whether the ratio (S1b' / S1b, S2b' / S2b, S3b' / S3b) of the measurement value of the flow rate sensor 313 (second flow rate sensor) to the measurement value of the flow rate sensor 312 (first flow rate sensor) is equal to or greater than a predetermined threshold value CL (predetermined ratio). With this configuration, it is possible to perform irrigation control that promotes the growth of the plant 304, such as by determining the amount and timing of water delivery by the irrigation device 6 so as to reduce the flow rate of sap flowing through an upper portion in order to increase the sugar content of the plant 304, such as a tomato.

[0139] Furthermore, in the irrigation system 300 according to the third embodiment, when the ratios of the measured values ​​(S1c / S1b, S2c / S2b, S3c / S3b) are equal to or greater than a predetermined threshold value CL (predetermined ratio), the control device 8 controls the amount of water delivered by the irrigation device 6 to be relatively smaller than when the ratios of the measured values ​​are not equal to or greater than the predetermined threshold value CL. With this configuration, it is possible to perform irrigation control that promotes the growth of the plant 304, such as by determining the amount of water delivered by the irrigation device 6 so that the amount of sap flowing through an upper portion is relatively small in order to increase the sugar content of the plant 304, such as a tomato.

[0140] Furthermore, in the irrigation system 300 according to the third embodiment, the control device 8 controls the operation of the irrigation device 6 based on the correlation between the integrated value of the measurement values ​​of the flow velocity sensor 312 (first flow velocity sensor) and the integrated value of the measurement values ​​of the flow velocity sensor 313 (second flow velocity sensor). With this configuration, by controlling the irrigation device 6 based on the correlation between the integrated values ​​(i.e., flow rates) of the measurement values ​​of the two flow velocity sensors 312, 313, it is possible to accurately control irrigation to promote the growth of the plant 304.

[0141] The irrigation method of embodiment 3 is a method for controlling the operation of an irrigation device 6 that supplies water to a plant 304, and controls the operation of the irrigation device 6 based on the correlation between the measured values ​​of a flow velocity sensor 312 (first flow velocity sensor) and a flow velocity sensor 313 (second flow velocity sensor), which are installed at different positions so as to measure the flow velocity of the sap flowing through the plant 304.

[0142] According to this method, it is possible to execute irrigation control with a simple configuration to promote the growth of plants 304. (Outline of Embodiments) <1> An irrigation system comprising an irrigation device that supplies water to plants, a control device that controls the operation of the irrigation device, and a first flow velocity sensor and a second flow velocity sensor that are installed at different positions so as to measure the flow velocity of sap flowing through the plants or the flow velocity of water flowing through the irrigation device, wherein the control device controls the operation of the irrigation device based on the correlation between the measurement value of the first flow velocity sensor and the measurement value of the second flow velocity sensor.

[0143] <2> The irrigation system described in <1>, wherein the first flow rate sensor is installed in the liquid delivery section of the irrigation device, and the second flow rate sensor is installed on the stem connecting to the leaf of the plant, and measures the flow rate of the sap flowing toward the leaf.

[0144] <3> The irrigation system described in <1>, wherein the first flow velocity sensor is installed on a stem connected to a leaf of the plant and measures the flow velocity of the sap flowing toward the leaf, and the second flow velocity sensor is installed on a stem connected to a fruit or flower of the plant and measures the flow velocity of the sap flowing toward the fruit or the flower.

[0145] <4> An irrigation system described in <2> or <3>, in which the control device determines the amount of water delivered by the irrigation device depending on whether the ratio of the measurement value of the second flow velocity sensor to the measurement value of the first flow velocity sensor is greater than or equal to a predetermined ratio.

[0146] <5> The irrigation system described in <4>, wherein the control device controls the amount of water delivered by the irrigation device to be relatively smaller when the ratio is not greater than the specified ratio than when the ratio is greater than the specified ratio.

[0147] <6> An irrigation system described in <2> or <3>, wherein the control device calculates the volume of the plant's roots relatively when the ratio of the measurement value of the second flow velocity sensor to the measurement value of the first flow velocity sensor becomes a predetermined ratio or greater.

[0148] <7> An irrigation system described in <1>, wherein the first flow velocity sensor is installed on a stem connecting to a leaf of the plant, and the second flow velocity sensor is installed on a stem connecting to a leaf of the plant at a higher position than the first flow velocity sensor.

[0149] <8> The control device determines the amount of water delivered by the irrigation device depending on whether the ratio of the measurement value of the second flow velocity sensor to the measurement value of the first flow velocity sensor is greater than or equal to a predetermined ratio.

[0150] <9> The irrigation system described in <8>, wherein the control device controls the amount of water delivered by the irrigation device to be relatively smaller when the ratio is greater than or equal to the specified ratio than when the ratio is not greater than or equal to the specified ratio.

[0151] <10> An irrigation system described in any one of <1> to <9>, wherein the control device controls the operation of the irrigation device based on the correlation between the integrated value of the measurement value of the first flow velocity sensor and the integrated value of the measurement value of the second flow velocity sensor.

[0152] <11> A program for controlling the operation of an irrigation device that supplies water to plants, which, when executed by a processor, causes the processor to control the operation of the irrigation device based on the correlation between the measured values ​​of a first flow rate sensor and a second flow rate sensor installed at different positions so as to measure the flow rate of sap flowing through the plant or the flow rate of water flowing through the irrigation device.

[0153] <12>. A method for controlling the operation of an irrigation device that supplies water to plants, the irrigation method controlling the operation of the irrigation device based on a correlation between measured values ​​of a first flow velocity sensor and a second flow velocity sensor that are installed at different positions so as to measure a flow velocity of sap flowing through the plant or a flow velocity of water flowing through the irrigation device.

[0154] <13> A computer-readable medium for controlling the operation of an irrigation device that supplies water to plants, which, when executed by a processor, causes the processor to control the operation of the irrigation device based on the correlation of the respective measurements of a first flow rate sensor and a second flow rate sensor installed at different positions to measure the flow rate of sap flowing through the plant or the flow rate of water flowing through the irrigation device.

[0155] Although the invention of the present disclosure has been described above with reference to the above-mentioned embodiments, the invention of the present disclosure is not limited to the above-mentioned embodiments.

[0156] Although the present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various variations and modifications will be apparent to those skilled in the art. Such variations and modifications should be understood to be included within the scope of the invention as defined by the appended claims, unless they depart therefrom. Furthermore, changes in the combination and order of elements in each embodiment may be made without departing from the scope and spirit of the present disclosure.

[0157] By appropriately combining any of the above-described embodiments and various modifications, it is possible to achieve the effects of each of the embodiments and modifications.

[0158] The present disclosure is useful for an irrigation system, an irrigation method, a program, and a computer-readable medium for irrigating plants.

[0159] 2 Irrigation system 4 Plant 6 Irrigation device 7 Liquid supply unit 8 Control device 9 Soil 10 Flow velocity sensor (first flow velocity sensor) 12 Flow velocity sensor (second flow velocity sensor) 16 Stem 18 Leaf 20 Fruit

Claims

1. An irrigation system comprising: an irrigation device that supplies water to plants; a control device that controls the operation of the irrigation device; and a first flow velocity sensor and a second flow velocity sensor that are installed at different positions so as to measure the flow velocity of sap flowing through the plant or the flow velocity of water flowing through the irrigation device, wherein the control device controls the operation of the irrigation device based on the correlation between the measurement values ​​of the first flow velocity sensor and the measurement values ​​of the second flow velocity sensor.

2. The irrigation system described in claim 1, wherein the first flow rate sensor is installed in the liquid delivery section of the irrigation device, and the second flow rate sensor is installed on a stem connecting to a leaf of the plant and measures the flow rate of sap flowing toward the leaf.

3. The irrigation system of claim 1, wherein the first flow rate sensor is installed on a stem leading to a leaf of the plant and measures the flow rate of sap flowing toward the leaf, and the second flow rate sensor is installed on a stem leading to a fruit or flower of the plant and measures the flow rate of sap flowing toward the fruit or flower.

4. An irrigation system as described in claim 2 or 3, wherein the control device determines the amount of water delivered by the irrigation device depending on whether the ratio of the measurement value of the second flow velocity sensor to the measurement value of the first flow velocity sensor is greater than or equal to a predetermined ratio.

5. The irrigation system of claim 4, wherein the control device controls the amount of water delivered by the irrigation device to be relatively smaller when the ratio is not greater than or equal to the specified ratio than when the ratio is greater than or equal to the specified ratio.

6. An irrigation system as described in claim 2 or 3, wherein the control device calculates the volume of the plant's roots relatively when the ratio of the measurement value of the second flow velocity sensor to the measurement value of the first flow velocity sensor becomes equal to or greater than a predetermined ratio.

7. The irrigation system of claim 1, wherein the first flow velocity sensor is installed on a stem connected to a leaf of the plant, and the second flow velocity sensor is installed on a stem connected to a leaf of the plant at a position higher than the first flow velocity sensor.

8. The irrigation system of claim 7, wherein the control device determines the amount of water delivered by the irrigation device depending on whether the ratio of the measurement value of the second flow velocity sensor to the measurement value of the first flow velocity sensor is greater than or equal to a predetermined ratio.

9. The irrigation system of claim 8, wherein the control device controls the amount of water delivered by the irrigation device to be relatively smaller when the ratio is equal to or greater than the specified ratio than when the ratio is not equal to or greater than the specified ratio.

10. An irrigation system described in any one of claims 1 to 9, wherein the control device controls the operation of the irrigation device based on the correlation between the integrated value of the measurement value of the first flow velocity sensor and the integrated value of the measurement value of the second flow velocity sensor.

11. A program for controlling the operation of an irrigation device that supplies water to plants, which, when executed by a processor, causes the processor to control the operation of the irrigation device based on the correlation between the respective measured values ​​of a first flow rate sensor and a second flow rate sensor installed at different positions so as to measure the flow rate of sap flowing through the plant or the flow rate of water flowing through the irrigation device.

12. A method for controlling the operation of an irrigation device that supplies water to a plant, comprising controlling the operation of the irrigation device based on the correlation between the measured values ​​of a first flow velocity sensor and a second flow velocity sensor that are installed at different positions so as to measure the flow velocity of sap flowing through the plant or the flow velocity of water flowing through the irrigation device.

13. A computer-readable medium for controlling the operation of an irrigation device that supplies water to a plant, which, when executed by a processor, causes the processor to control the operation of the irrigation device based on a correlation between respective measurement values ​​of a first flow rate sensor and a second flow rate sensor installed at different positions to measure a flow rate of sap flowing through the plant or a flow rate of water flowing through the irrigation device.

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