Watering control system

Abstract

The present invention comprises: a container (3) in which cultivation soil is placed; a watering device (20) that waters a cultivated plant (Q) planted in the cultivation soil placed in the container (3); an imaging device (5) that images the cultivated plant (Q); a spreading coefficient calculation unit (11) that calculates a spreading coefficient indicating the degree of spreading of branches and leaves; and a watering control unit (12) that controls driving of the watering device on the basis of the spreading coefficient.

Description

Irrigation Control System

[0001] The present invention relates to an irrigation control system for cultivated plants that are planted in culture soil placed in a container.

[0002] A method disclosed in Patent Document 1, for example, is known as a method for automatically controlling irrigation while applying water stress to cultivated plants planted in culture soil placed in a container.

[0003] Japanese Patent Application Laid-Open No. 2023-102502

[0004] Conventional methods have generally controlled irrigation by monitoring the condition of the container or the soil in the container, but there has been no focus on monitoring the cultivated plants themselves.

[0005] An object of the present invention is to provide an irrigation control system that can control irrigation by monitoring the cultivated plants themselves as they are planted in culture soil placed in a container.

[0006] The irrigation control system of the present invention is characterized by comprising a container containing culture soil, an irrigation device that irrigates cultivated plants planted in the culture soil placed in the container, an imaging device that images the cultivated plants, a tension coefficient calculation unit that calculates a tension coefficient that indicates the tension of the branches and leaves, and an irrigation control unit that controls the operation of the irrigation device based on the tension coefficient.

[0007] According to the present invention, an image of a cultivated plant planted in a container containing culture soil is captured by an imaging device, and a tension coefficient indicating the tension of the cultivated plant's branches and leaves is calculated. This configuration makes it possible to monitor the water stress status of the cultivated plant and automatically control irrigation based on the tension coefficient. This realizes an irrigation control system that can control irrigation by monitoring the cultivated plant itself planted in a container containing culture soil.

[0008] In the present invention, it is preferable that a plurality of the containers are provided, and a plurality of the cultivated plants planted in the culture soil of each of the plurality of containers are positioned within the imaging range of the imaging device.

[0009] With this configuration, the imaging device can simultaneously capture images of multiple cultivated plants that are each planted in culture soil placed in multiple containers, and the tension coefficient calculation unit can simultaneously calculate the tension coefficient for multiple cultivated plants.

[0010] In the present invention, it is preferable that the plurality of containers are configured to be individually movable.

[0011] With this configuration, even if at least one of the multiple cultivated plants planted in the culture soil in each of the multiple containers becomes diseased, the diseased plant can simply be moved to another location, allowing the tension coefficient calculation unit to accurately calculate the tension coefficient for the remaining cultivated plants.

[0012] In the present invention, it is preferable that a fixed support portion is provided on which the plurality of movable containers are individually placed and supported.

[0013] With this configuration, the fixed support parts make it easy to fix and move each of the multiple containers.

[0014] In the present invention, the container is preferably configured to allow water to pass through but not allow roots of the cultivated plants to pass through.

[0015] This configuration improves drainage of the container, making it less likely for the roots of the cultivated plants to rot. In addition, the configuration that prevents the roots of the cultivated plants from passing out of the container inhibits root growth of the cultivated plants, suppressing the vigor of the cultivated plants and enabling them to bear fruit earlier.

[0016] In the present invention, it is preferable that the irrigation device is provided with a top dressing section that can supply nitrogen to be mixed into the irrigation water, and an upper limit setting section that sets an upper limit for the amount of nitrogen that can be supplied by the irrigation device.

[0017] This configuration makes it easy to manage the amount of nitrogen supplied to cultivated plants, thereby preventing excessive nitrogen supply to cultivated plants and making it less likely for cultivated plants to develop vine rot and other problems.

[0018] In the present invention, the upper limit of the supply amount is preferably a supply amount per day.

[0019] This configuration makes it easier to control the amount of nitrogen supplied to cultivated plants.

[0020] Fig. 1 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. 3 is a plan view showing the imaging range and measurement area of ​​an imaging device. Fig. 4 is a block diagram showing the configuration of an irrigation control system. Fig. 5 is a diagram showing an example of the transition of coverage rate. Fig. 6 is a diagram showing a setting screen for setting an upper limit of the supply amount of liquid fertilizer. Fig. 7 is a flowchart showing the flow of irrigation control. Fig. 8 is a diagram showing a calculation screen for calculating an upper limit value of the supply amount of liquid fertilizer and an upper limit value of the supply time.

[0021] [Configuration of Horticultural Facility] An embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2 , an irrigation control system in this embodiment includes a horticultural facility 1. The horticultural facility 1 includes a plurality of fixed support members 2 arranged in parallel, each extending in one direction, and a plurality of containers 3 arranged in a line on each of the fixed support members 2. The containers 3 are configured to allow, for example, potted tomatoes to be grown. A plurality of containers 3 arranged in a line on the fixed support members 2 is referred to as one line of containers 3. The containers 3 in one line are arranged in a line along the longitudinal direction of the fixed support members 2. In this embodiment, as shown in FIG. 1 , there are three lines of containers 3. Therefore, the containers 3 can be defined as a first line of containers 3, a second line of containers 3, and a third line of containers 3, from top to bottom in FIG. 1 .

[0022] Although not shown in FIG. 1 , culture soil is placed in the containers 3, and cultivated plants Q are planted in the culture soil. For example, tomatoes are planted as the cultivated plants Q. Passages are provided between each of the fixed support parts 2 so that managers of the cultivated plants Q (including workers, operators, etc.) can pass through. The horticultural facility 1 may be, for example, a greenhouse or a solar-powered plant factory. In this embodiment, there are three lines of cultivated plants Q in the horticultural facility 1, corresponding to the three lines of containers 3. Therefore, the cultivated plants Q can be defined as a first line of cultivated plants Q, a second line of cultivated plants Q, and a third line of cultivated plants Q, from top to bottom in FIG. 1 .

[0023] A soil moisture sensor 4 is disposed in at least one of the first line containers 3. The same is true for the second line containers 3 and the third line containers 3. The probe tip of the soil moisture sensor 4 is embedded in the culture soil in the container 3. The soil moisture sensor 4 is configured to be able to detect the volumetric water content of the culture soil in the container 3, the electrical conductivity of the culture medium, the temperature of the culture medium, etc.

[0024] The irrigation control system of this embodiment includes multiple imaging devices 5. In Figures 1 and 2, the imaging range R of each of the multiple imaging devices 5 is indicated by a dashed line. The multiple cultivated plants Q planted in the culture soil of each of the multiple containers 3 are located within the imaging range R of the imaging device 5. The multiple imaging devices 5 are arranged so that their imaging ranges R do not overlap. In this embodiment, one imaging device 5 is provided for each of the first line of cultivated plants Q, the second line of cultivated plants Q, and the third line of cultivated plants Q. Although Figure 1 shows three imaging devices 5, the number of imaging devices 5 may be one, two, four or more.

[0025] Each imaging device 5 has, for example, a CCD element or a CMOS element and is configured to capture visible light visible to the naked eye. Each imaging device 5 captures an overhead image of the leaves of the cultivated plant Q at predetermined time intervals (for example, every 60 seconds). As a result, each imaging device 5 acquires captured images over time, as shown in FIG. 3 .

[0026] That is, the irrigation control system of this embodiment is equipped with an imaging device 5 that captures images of the leaves of the cultivated plant Q. The imaging device 5 is configured to capture images of the leaves of the cultivated plant Q from a bird's-eye view. The imaging device 5 may be, for example, a stereo camera, or may be configured to include a so-called LiDAR unit (optical ranging unit) and be capable of measuring the distance to the leaves, stems, etc. of the cultivated plant Q. With this configuration, it is possible to measure the distance between the imaging device 5 and key parts of the cultivated plant Q, such as the leaves and stems, and to accurately calculate the tooth area and stem diameter.

[0027] Although not shown, the horticultural facility 1 is also equipped with a spray device, an environmental sensor, side windows, blackout curtains, a heat pump type air conditioning system, etc. Also, a guide string for guiding the stems of the cultivated plants Q hangs down from near the ceiling of the horticultural facility 1.

[0028] The fixed support unit 2 individually supports and mounts a plurality of movable containers 3. Therefore, the first line of containers 3, the second line of containers 3, and the third line of containers 3 are each configured to be individually movable. With this configuration, even if at least one of the cultivated plants Q becomes ill, for example, it is possible to move the diseased cultivated plant Q outside the imaging range R. This allows the imaging device 5 to continue imaging only healthy cultivated plants Q.

[0029] The container 3 is configured to allow water to pass through but not allow the roots of the cultivated plant Q to pass through. The container 3 is made of, for example, a nonwoven fabric made of polyester, polyethylene, or the like, or a high-density woven fabric made of polyester, polyethylene, or the like. This improves drainage of the container 3, making it less likely for the cultivated plant Q to develop root rot or the like. Furthermore, by preventing the roots of the cultivated plant Q from passing out of the container 3, root growth of the cultivated plant Q is suppressed, suppressing the vigor of the cultivated plant Q and enabling it to bear fruit early. Furthermore, this prevents the roots of the cultivated plant Q from unintentionally taking root in other containers 3, etc., thereby avoiding problems such as the spread of diseases from the cultivated plant Q to other cultivated plants Q.

[0030] [Configuration of Irrigation Control System] As shown in FIG. 4 , the irrigation control system of this embodiment includes a management computer 10 and an irrigation device 20 .

[0031] The management computer 10 has a calculation unit 11 , an irrigation control unit 12 , a storage device 13 , a communication unit 14 , an operation input unit 15 , a display 16 , and a buzzer 17 .

[0032] The calculation unit 11 is configured, for example, by a processor, software, or a combination of a processor and software. The irrigation control unit 12 is configured, for example, by at least one of a processor, software, FPGA (Field Programmable Gate Array), PLC (Programmable Logic Controller), etc. The calculation unit 11 and irrigation control unit 12 may be configured as an integrated module.

[0033] The storage device 13 may be, for example, a hard disk or a flash memory. The communication unit 14 may be, for example, a serial bus port or a network communication port connected via an 8-pole 8-core connector. The communication unit 14 is a port that can be connected to devices other than the management computer 10. In this embodiment, the communication unit 14 is connected to the soil moisture sensor 4, the imaging device 5, and the primary on-off valve 23A, bypass on-off valve 23B, mixing on-off valve 23C, first line on-off valve 23D, second line on-off valve 23E, and third line on-off valve 23F of the irrigation device 20.

[0034] The display 16 can display, for example, the operating status of the irrigation control system, a setting screen, etc. The buzzer 17 outputs a sound, for example, when there is a change in the operating status of the irrigation control system. The operation input unit 15 can be, for example, a computer mouse or a touch screen attached to the display 16. The operation input unit 15 accepts the designation of a coordinate point on the screen displayed on the display 16 based on a manual operation. If the operation input unit 15 is a touch screen, the manual operation means that the operator touches the touch screen. If the operation input unit 15 is a computer mouse, the manual operation means that the operator performs an operation such as clicking on the computer mouse.

[0035] The irrigation device 20 irrigates cultivated plants Q planted in culture soil placed in a container 3. The irrigation device 20 includes a water storage tank 21, an electric pump 22, a primary on-off valve 23A, a bypass on-off valve 23B, a mixing on-off valve 23C, a first line on-off valve 23D, a second line on-off valve 23E, a third line on-off valve 23F, a relief valve 24, liquid fertilizer tanks 25A and 25B, flow rate adjustment valves 26A and 26B, mixing valves 27A and 27B, check valves 28A and 28B, and a controller 30.

[0036] The controller 30 is connected by electrical cables to the pump 22, the primary on-off valve 23A, the bypass on-off valve 23B, the mixing on-off valve 23C, the first line on-off valve 23D, the second line on-off valve 23E, and the third line on-off valve 23F. The controller 30 is configured, for example, by a PLC (programmable logic controller), and controls the energization / cutoff of the pump 22, the primary on-off valve 23A, the bypass on-off valve 23B, the mixing on-off valve 23C, the first line on-off valve 23D, the second line on-off valve 23E, and the third line on-off valve 23F in response to a command signal from the irrigation control unit 12. Each of the primary on-off valve 23A, the bypass on-off valve 23B, the mixing on-off valve 23C, the first line on-off valve 23D, the second line on-off valve 23E, and the third line on-off valve 23F is, for example, a solenoid valve that opens when it receives current from the controller 30 and closes when it no longer receives current from the controller 30.

[0037] Water for irrigation is stored in the water storage tank 21. A water supply pipe 29 for irrigation is laid between the water storage tank 21 and the container 3. A pump 22 is provided in the water supply pipe 29 on the upstream side adjacent to the water storage tank 21. A primary on-off valve 23A is provided downstream of the pump 22. When the pump 22 is driven, the primary on-off valve 23A opens, and the pump 22 draws water from the water storage tank 21 and supplies it to the downstream side of the water supply pipe 29. A return pipe 29A branches off downstream of the primary on-off valve 23A and leads to the water storage tank 21. A relief valve 24 is provided in the return pipe 29A. When the water pressure in the water supply pipe reaches or exceeds a preset pressure, the relief valve 24 opens, and water is returned from the return pipe 29A to the water storage tank 21.

[0038] In this embodiment, the end of the irrigation water supply pipe 29, which is located away from the water storage tank 21, branches into a first branch line 29D, a second branch line 29E, and a third branch line 29F to accommodate the three lines of cultivated plants Q. Each of the first branch line 29D, the second branch line 29E, and the third branch line 29F is provided with a plurality of nozzles 29N, and each of the plurality of nozzles 29N is inserted into the culture soil in the container 3. The first branch line 29D is provided with a first line opening / closing valve 23D, the second branch line 29E is provided with a second line opening / closing valve 23E, and the third branch line 29F is provided with a third line opening / closing valve 23F.

[0039] A bypass pipe 29B and a mixing pipe 29C are arranged in parallel downstream of the branch point where the return pipe 29A branches and upstream of the branch point where the first branch line 29D, the second branch line 29E, and the third branch line 29F branch off from the water supply pipe 29. The water supply pipe 29 branches off into the bypass pipe 29B and the mixing pipe 29C downstream of the branch point where the return pipe 29A branches off. Furthermore, the bypass pipe 29B and the mixing pipe 29C merge upstream of the branch point where the first branch line 29D, the second branch line 29E, and the third branch line 29F branch off from the water supply pipe 29.

[0040] The bypass pipe 29B is provided with a bypass on-off valve 23B and a check valve 28A. The check valve 28A is disposed downstream of the bypass on-off valve 23B.

[0041] The mixing pipe 29C is provided with a mixing on-off valve 23C, mixing valves 27A and 27B, and a check valve 28B. The mixing valves 27A and 27B are arranged downstream of the mixing on-off valve 23C, and the check valve 28B is arranged downstream of the mixing valves 27A and 27B.

[0042] Concentrated liquid fertilizer is stored in liquid fertilizer tanks 25A and 25B. The concentrated liquid fertilizer contains nitrogen, phosphate, and potassium. The concentrated liquid fertilizer may also contain calcium, magnesium, and other elements. Liquid fertilizer tank 25A is connected to mixing valve 27A via a pipe, and flow control valve 26A is located between liquid fertilizer tank 25A and mixing valve 27A. Liquid fertilizer tank 25B is connected to mixing valve 27B via a pipe, and flow control valve 26A is located between liquid fertilizer tank 25B and mixing valve 27B. Each of flow control valves 26A and 26B is equipped with an adjustment screw. When an operator turns the adjustment screw, the flow rate of flow control valves 26A and 26B changes. Therefore, an operator can adjust the dilution ratio of the liquid fertilizer in mixing valves 27A and 27B by turning each adjustment screw of flow control valves 26A and 26B. Liquid fertilizer tanks 25A and 25B are provided in irrigation device 20 and function as a top dressing unit capable of supplying nitrogen to be mixed with irrigation water. Liquid fertilizer tanks 25A and 25B may be integrated. In this case, there may be only one flow control valve 26A, 26B, and there may be only one mixing valve 27A, 27B.

[0043] [Irrigation Control Process] Irrigation control is performed based on whether or not there is a moisture deficiency in the cultivated plant Q. Whether or not there is a moisture deficiency in the cultivated plant Q is often determined based on the moisture content of the culture soil in the container 3. For this reason, it is possible to configure the system to perform irrigation control based on the volumetric water content of the culture soil detected by the soil moisture sensor 4.

[0044] However, the inventors of the present application discovered during research that as the cultivated plant Q grows and the proportion of the roots of the cultivated plant Q in the container 3 increases, variations in the volumetric water content tend to occur in localized areas of the culture medium, reducing the accuracy of detecting the volumetric water content by the soil moisture sensor 4. For example, if the probe of the soil moisture sensor 4 is inserted deep into the culture medium or if the nozzle 29N and the probe of the soil moisture sensor 4 are separated by the roots of the cultivated plant Q, water may not reach the probe of the soil moisture sensor 4 even when the cultivated plant Q is watered, and the detected value of the volumetric water content by the soil moisture sensor 4 may not change. For this reason, in this embodiment, whether the cultivated plant Q is deficient in water is determined based on the degree of leaf firmness of the cultivated plant Q.

[0045] The flow of irrigation control in this embodiment will be described with reference to Figures 3 to 5. Each imaging device 5 captures an image of one line of cultivated plants Q captured in an imaging range R at predetermined time intervals, and transmits the captured image data to the calculation unit 11 via the communication unit 14.

[0046] The calculation unit 11 calculates the coverage rate Br of one line of cultivated plant Q over time based on the received captured image. The coverage rate Br is the proportion of the area occupied by leaves in the measurement area B (see Figure 3), which is the area in the captured image where the leaves are captured. The coverage rate Br is also a value indicating the degree of leaf tension. In other words, the coverage rate Br corresponds to the "tension coefficient" of the present invention. The calculation unit 11 also functions as a tension coefficient calculation unit that calculates the tension coefficient, which indicates the degree of tension of the branches and leaves of the cultivated plant Q.

[0047] 3, the calculation unit 11 determines the areas of branches, leaves, and stems in the captured image based on color information of the captured image, etc. This area is determined to be a lush area of ​​the cultivated plant Q, i.e., a covered area.

[0048] The determination of the regions of branches, leaves, and stems may be performed based on RGB data or YUV data, but in this embodiment, it is preferable to perform the determination of the regions of branches, leaves, and stems based on YUV data in order to accommodate changes in brightness that occur with changes in weather and time of day.

[0049] Then, based on the determination of the covered area, the range in the captured image in which the cultivated plant Q is located is set. As shown in Fig. 3, an area surrounded by four sides is set as the area in which the branches and leaves of the cultivated plant Q are captured, and this area surrounded by four sides is set as a 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 a captured image) in the measurement area B of the captured image.

[0050] 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 Br using the following formula:

[0051] Coverage rate Br = leaf area B1 / area Bs

[0052] It is desirable that the area Bs of the measurement region B be fixed at the area Bs before the leaves began to wilt, even if the leaves 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 among multiple captured images acquired over time, and that only the leaf area B1 change over time.

[0053] In this embodiment, three imaging devices 5 are provided. Therefore, the calculation unit 11 calculates over time the coverage rate Br of the cultivated plants Q of the first line, the coverage rate Br of the cultivated plants Q of the second line, and the coverage rate Br of the cultivated plants Q of the third line, depending on whether the imaging device 5 is arranged on the first line, the second line, or the third line. In other words, the calculation unit 11 is configured to calculate the coverage rate Br, which indicates the leaf tension coefficient of the cultivated plants Q, based on the captured images. The coverage rate Br is sent to the irrigation control unit 12.

[0054] In this embodiment, the coverage rate Br in the time slot immediately after sunrise is treated as the reference value ST. Furthermore, an operator or the like can input a wilting coefficient via the operation input unit 15. The wilting coefficient is a coefficient corresponding to the degree of wilting of the target leaves. The irrigation control unit 12 calculates the irrigation start reference value TH by multiplying the reference value ST by the wilting coefficient. That is, the irrigation control unit 12 is configured to set the coverage rate Br in the time slot immediately after sunrise as the reference value ST and calculate the irrigation start reference value TH based on the reference value ST and the wilting coefficient.

[0055] When the management computer 10 and the controller 30 of the irrigation device 20 are able to communicate via the communication unit 14, the control source of the irrigation device 20 is the management computer 10. When the control source of the irrigation device 20 is the management computer 10, the irrigation control unit 12 determines whether the coverage rate Br is below the irrigation start reference value TH based on the coverage rate Br received from the calculation unit 11 and the calculated irrigation start reference value TH. When the coverage rate Br is below the irrigation start reference value TH, the irrigation control unit 12 outputs an irrigation instruction signal to the controller 30 of the irrigation device 20.

[0056] The controller 30 irrigates the cultivated plants Q belonging to the corresponding line in response to the irrigation instruction signal received from the irrigation control unit 12. Specifically, the controller 30 opens the primary on-off valve 23A, opens the bypass on-off valve 23B or the mixing on-off valve 23C, opens the valves communicating with the culture soil in the container 3 of the corresponding line among the first line on-off valve 23D, the second line on-off valve 23E, and the third line on-off valve 23F, and supplies power to the pump 22 to drive the pump 22. As a result, water is sent from the water storage tank 21 toward the nozzle 29N inserted into the culture soil in the container 3 of the corresponding line.

[0057] If the management computer 10 and the controller 30 of the irrigation device 20 cannot communicate via the communication unit 14, the controller 30 becomes the control source of the irrigation device 20. In this case, the controller 30 performs irrigation based on a logic preset inside the controller 30. The logic preset inside the controller 30 may be, for example, irrigation control at preset time intervals or irrigation control based on a preset schedule.

[0058] As shown in Figure 5, the coverage ratios Br of the first and second lines basically change as follows: First, the leaves wilt over time, which causes the coverage ratio Br to decrease over time.

[0059] When the coverage rate Br falls below the watering start reference value TH, watering is performed. This causes the leaf firmness to recover and the coverage rate Br to increase. In other words, the progression of leaf wilting over time and the recovery of leaf firmness through watering are repeated. As a result, the coverage rate Br alternately decreases and increases.

[0060] In the example shown in the upper part of Fig. 5, the timings at which the irrigation instruction signal was output by the irrigation control unit 12 are indicated by upward arrows. In this example, the coverage rate Br fell below the irrigation start reference value TH at each of times t1, t2, t4, and t6, and therefore the irrigation instruction signal was output by the irrigation control unit 12. As a result, irrigation of the first line was performed, and as a result, the coverage rate Br exceeded the irrigation start reference value TH.

[0061] 5, the timing at which the irrigation control unit 12 outputs an irrigation instruction signal is indicated by an upward arrow. In this example, the coverage rate Br falls below the irrigation start reference value TH at times t3 and t5, and the irrigation control unit 12 outputs an irrigation instruction signal. As a result, irrigation of the second line is performed, and the coverage rate Br exceeds the irrigation start reference value TH.

[0062] In this way, the irrigation control unit 12 controls the operation of the irrigation device 20 based on the coverage rate Br, which indicates the tension coefficient.

[0063] In the example shown in Figure 5, the wilting coefficient of the second line is manually set by an operator or the like to a value smaller than the wilting coefficient of the first line. Therefore, the irrigation start reference value TH of the second line is lower than the irrigation start reference value TH of the first line. As a result, the number of times the second line is irrigated is less than the number of times the first line is irrigated.

[0064] [Limiting the amount of liquid fertilizer supplied] As shown in Figure 4, a bypass pipe 29B and a mixing pipe 29C, which passes through mixing valves 27A and 27B for mixing fertilizer, are connected in parallel to the irrigation water supply pipe 29. The bypass on-off valve 23B and the mixing on-off valve 23C are not opened simultaneously; only one of them is opened. When the bypass on-off valve 23B is opened, irrigation water passes through the bypass pipe 29B, and only water is supplied to the cultivated plant Q, without liquid fertilizer. When the mixing on-off valve 23C is opened, irrigation water passes through the mixing pipe 29C, and liquid fertilizer is mixed with the irrigation water, and diluted liquid fertilizer water is supplied to the cultivated plant Q.

[0065] However, if the amount of liquid fertilizer supplied is too large, the cultivated plants Q will become too vigorous, and they will be more susceptible to vine fading and end rot, resulting in reduced yields and distorted fruit shape. For this reason, it is desirable to set an upper limit on the amount of liquid fertilizer supplied per day (amount of liquid supplied). In this embodiment, the system is configured so that an upper limit on the amount of liquid fertilizer supplied per day can be set.

[0066] 6, the display 16 of the management computer 10 can display a setting screen 40 for setting an upper limit of the amount of liquid fertilizer to be supplied per day. On the setting screen 40, an operator can operate an ON / OFF setting button 41 for limiting the supply amount for each line, an upper limit setting section 42 for the supply amount for each line, and a calculation button 43.

[0067] 6 shows ON / OFF setting buttons 41 for the first through twelfth lines and an upper limit setting section 42. At least twelve second counters are set corresponding to the first through twelfth lines, respectively. Each second counter for the first through twelfth lines is configured so that an upper limit for the fluid supply amount can be set using the upper limit setting section 42. When an ON / OFF setting button 41 is pressed, the fluid supply amount limit for the corresponding line is switched between ON and OFF.

[0068] In this embodiment, there are first to third lines. Therefore, the ON / OFF setting buttons 41 and upper limit setting units 42 of the first to third lines are enabled so that they can be operated, and the ON / OFF setting buttons 41 and upper limit setting units 42 of the fourth to twelfth lines are disabled so that they cannot be operated. The setting values ​​set by the ON / OFF setting buttons 41 and upper limit setting units 42 for each line are sent from the irrigation control unit 12 to the controller 30.

[0069] The following description will be based on the flowchart in Fig. 7. The flowchart in Fig. 7 may be an independent flowchart for each of the first to third lines, or may be a flowchart for managing all of the first to third lines collectively.

[0070] The irrigation control unit 12 determines whether the coverage rate Br for any one of the first to third lines has become equal to or less than the irrigation start reference value TH, and determines whether it is time to irrigate the cultivated plant Q for that line (Step #01). If the coverage rate Br is greater than the irrigation start reference value TH and the cultivated plant Q for that line is not in a state where it is time to irrigate (Step #01: No), the determination in Step #01 is repeated.

[0071] When it is time to water the cultivated plant Q on the corresponding line (step #01: Yes), the irrigation control unit 12 outputs a command signal to the controller 30 instructing the irrigation, and the controller 30 opens the primary on-off valve 23A, opens one of the first line on-off valve 23D, the second line on-off valve 23E, and the third line on-off valve 23F on the corresponding line, and drives the pump 22 (step #02).

[0072] The controller 30 determines whether one of the liquid fertilizer supply amount limit settings shown in Fig. 6 is set to ON for the corresponding line (step #03). If the setting for the corresponding line is set to OFF (step #03: No), the controller 30 closes the bypass on-off valve 23B and opens the mixing on-off valve 23C (step #04). As a result, dilution water mixed with liquid fertilizer from the liquid fertilizer tanks 25A, 25B is supplied to the cultivated plants Q of the corresponding line via the nozzles 29N.

[0073] If the liquid fertilizer supply rate limit setting is ON (Step #03: Yes), the controller 30 determines whether the second counter for the corresponding line is equal to or greater than the upper limit set by the upper limit setting unit 42 (Step #05). If the second counter for the corresponding line is less than the upper limit (Step #05: No), the controller 30 closes the bypass on-off valve 23B and opens the mixing on-off valve 23C (Step #06), as in Step #04 above. This causes the dilution water mixed with the liquid fertilizer from the liquid fertilizer tanks 25A, 25B to be supplied to the cultivated plants Q of the corresponding line. At this time, the second counter for the corresponding line is incremented in Step #06.

[0074] If the second counter for the corresponding line is equal to or greater than the upper limit (step #05: Yes), the controller 30 opens the bypass on-off valve 23B and closes the mixing on-off valve 23C (step #07). As a result, the liquid fertilizer in the liquid fertilizer tanks 25A, 25B is no longer supplied to the cultivated plants Q, and only water is supplied to the cultivated plants Q on the corresponding line.

[0075] The controller 30 determines whether the irrigation is complete (step #08). The determination method may be a method of determining whether a timer that measures the duration of the irrigation has reached a preset upper limit value, or a method of determining whether the detection value of a flow meter provided in the water supply pipe 29 has exceeded a preset threshold value. If the irrigation is not complete (step #08: No), the process returns to step #03.

[0076] When irrigation is completed (step #08: Yes), the controller 30 stops the pump 22, closes the primary on-off valve 23A, and closes the first line on-off valve 23D, the second line on-off valve 23E, and the third line on-off valve 23F (step #09).

[0077] The irrigation control unit 12 or the controller 30 determines whether the date has changed (step #10). If the date has not changed (step #10: No), the process returns to step #01. If the time has crossed midnight and the date has changed (step #10: Yes), the second counters for all lines are reset (step #11), and the process returns to step #01. The resetting of the second counters may be performed by the irrigation control unit 12 or the controller 30.

[0078] The upper limit setting unit 42 is configured to be able to set an upper limit for the number of seconds for the liquid fertilizer supply time (number of seconds for liquid supply). However, if the upper limit is simply set, it is often unclear how much liquid fertilizer is actually being supplied, which may make it difficult for users to use. For this reason, in this embodiment, a calculation screen 50 (see FIG. 8 ) can be displayed on the display 16, which can display the upper limit for the amount of liquid fertilizer supply and the upper limit for the supply time, based on the amount of nitrogen that the user wants to supply to the cultivated plants Q per day.

[0079] When the operator touches the calculation button 43 shown in Fig. 6, a calculation screen 50 shown in Fig. 8 is displayed on the display 16. As shown in Fig. 8, the calculation screen 50 is provided with a nitrogen amount setting section 51, a nitrogen concentration coefficient setting section 52, a raw water EC setting section 53, a set EC setting section 54, a liquid supply amount display section 55, a nozzle discharge amount setting section 56, and a liquid supply time display section 57. When the operator touches the end button 58 shown in Fig. 8, the display screen on the display 16 returns to the setting screen 40 shown in Fig. 6.

[0080] An operator or the like can input setting values ​​into the nitrogen amount setting section 51 , the nitrogen concentration coefficient setting section 52 , the raw water EC setting section 53 , the set EC setting section 54 , and the nozzle discharge amount setting section 56 .

[0081] The nitrogen amount setting unit 51 receives a setting of the amount of nitrogen that a user or the like wants to supply per day to one line of cultivated plants Q. The amount of nitrogen set in the nitrogen amount setting unit 51 is the weight of nitrogen, and the unit is, for example, mg (milligrams).

[0082] The nitrogen concentration coefficient setting unit 52 receives the setting of the nitrogen concentration coefficient of the liquid fertilizer. In this embodiment, the nitrogen concentration coefficient is the weight of nitrogen contained in a unit volume of the dilution water of the liquid fertilizer, and the unit is, for example, mg / L (milligrams per liter).

[0083] The nitrogen concentration coefficient is provided, for example, by liquid fertilizer manufacturers or seedling producers. The higher the nitrogen concentration coefficient, the higher the electrical conductivity of the liquid fertilizer dilution water. Therefore, the relationship between electrical conductivity and nitrogen concentration coefficient can be displayed in a correspondence table, graph, or the like. While checking a correspondence table, graph, or the like provided by, for example, the liquid fertilizer manufacturer, an operator sets the nitrogen concentration coefficient for a state in which the electrical conductivity is 1.0 mS / cm (millisiemens per centimeter) in the nitrogen concentration coefficient setting unit 52.

[0084] The raw water EC setting unit 53 receives the setting of the electrical conductivity of the water stored in the water storage tank 21. For example, an operator or the like immerses the probe tip of the conductivity sensor in the water in the water storage tank 21, checks the electrical conductivity displayed on the conductivity sensor, and sets the electrical conductivity of the raw water in the raw water EC setting unit 53.

[0085] The operator or the like sets the electrical conductivity of the water for diluting the liquid fertilizer in the set EC setting unit 54, aiming for a value that is approximately 0.5 to 1.0 mS / cm higher than the electrical conductivity set in the raw water EC setting unit 53. For example, guidelines may be set such that when the electrical conductivity of the diluted solution after mixing is approximately 1.0 mS / cm higher than the electrical conductivity set in the raw water EC setting unit 53, the dilution ratio of the liquid fertilizer is approximately 500 times, and when the electrical conductivity of the diluted solution after mixing is approximately 0.5 mS / cm higher than the electrical conductivity set in the raw water EC setting unit 53, the dilution ratio of the liquid fertilizer is approximately 1000 times.

[0086] In the mixing valves 27A, 27B, an operator, for example, places the probe tip of the conductivity sensor in the diluted liquid fertilizer water (diluted water after mixing), and adjusts the aperture of the flow control valves 26A, 26B by turning the adjusting screws of the flow control valves 26A, 26B so that the electrical conductivity displayed on the conductivity sensor matches the electrical conductivity set in the EC setting unit 54. At this time, the pump 22 is manually driven, the mixing on-off valve 23C is opened, and the bypass on-off valve 23B is closed.

[0087] Once the numerical settings in the nitrogen amount setting unit 51, nitrogen concentration coefficient setting unit 52, raw water EC setting unit 53, and set EC setting unit 54 are completed, the total amount of liquid fertilizer to be supplied per day is calculated. In the formula below, the total amount of liquid fertilizer to be supplied per day is defined as X. X = (Ns × (ECr - ECo)) / (Nc × (ECs - ECo)) Ns is the amount of nitrogen set in the nitrogen amount setting unit 51. Nc is the nitrogen concentration coefficient set in the nitrogen concentration coefficient setting unit 52. ECo is the electrical conductivity set in the raw water EC setting unit 53. ECs is the electrical conductivity set in the set EC setting unit 54. ECr is an electrical conductivity of 1.0 mS / cm. The total amount of supply X is displayed in mL (milliliters) on the liquid supply amount display unit 55.

[0088] The nozzle discharge rate setting unit 56 accepts a setting for the discharge rate per unit time of dilution water discharged from each nozzle 29N in the first branch path 29D, the second branch path 29E, or the third branch path 29F. For example, an operator removes each of the multiple nozzles 29N in the first branch path 29D from the container 3 and measures the actual discharge rate of each nozzle 29N. At this time, the pump 22 is manually driven. The measurement time may be, for example, 1 to 10 minutes. The operator then converts the actually measured discharge rate into a total hourly discharge rate of the multiple nozzles 29N in the first branch path 29D, and sets the converted value in the nozzle discharge rate setting unit 56. In FIG. 8 , the discharge rate per hour is expressed in L / h (liters per hour). The nozzle discharge rate setting unit 56 may set the total hourly discharge rate of the multiple nozzles 29N, or the hourly discharge rate of each nozzle 29N.

[0089] Once the numerical setting of the discharge rate has been completed in the nozzle discharge rate setting unit 56, the supply time of liquid fertilizer per day is calculated using the following formula. In the formula below, the supply time of liquid fertilizer per day is defined as Y. Y = X / V X is the total supply amount of liquid fertilizer per day displayed in the liquid supply rate display unit 55 converted into L (liters). V is the discharge amount per hour set in the nozzle discharge rate setting unit 56, and the unit of V is L / h (liters per hour). The supply time Y is displayed in the liquid supply time display unit 57 as a value converted into seconds.

[0090] The operator can set the upper limit of the amount of liquid fertilizer to be supplied per day for any line by entering the number of seconds of the supply time displayed on the supply time display unit 57 in the upper limit setting unit 42. In this way, the upper limit setting unit 42 sets the upper limit of the amount of nitrogen to be supplied by the irrigation device 20.

[0091] Other Embodiments The present invention is not limited to the configurations exemplified in the above-described embodiments, and other representative embodiments of the present invention will be exemplified below.

[0092] (1) The container 3 is configured to allow for potted cultivation of, for example, tomatoes. In addition to tomatoes, the container 3 may be configured to allow for potted cultivation of strawberries, melons, gourds, bitter melons, paprika, bell peppers, cucumbers, eggplants, chili peppers, etc. Therefore, the cultivated plant Q may be, in addition to tomatoes, strawberries, melons, gourds, bitter melons, paprika, bell peppers, cucumbers, eggplants, chili peppers, etc.

[0093] (2) The upper limit setting unit 42 sets an upper limit for the amount of nitrogen supplied by the irrigation device 20. The upper limit setting unit 42 is not limited to nitrogen, and may be configured to set an upper limit for the amount of phosphoric acid, potassium, calcium, magnesium, or the like supplied, for example.

[0094] (3) The irrigation device 20 may not be provided with the water storage tank 21. In this case, the pump 22 may pump water from a reservoir or an underground water vein. The irrigation device 20 may also not be provided with the pump 22. In this case, the irrigation device 20 may be connected to an agricultural water pipeline and receive agricultural water when the primary on-off valve 23A is opened.

[0095] (4) The upper limit setting unit 42 accepts the setting of the upper limit of the number of seconds for the liquid fertilizer supply time per line. Without being limited to this embodiment, the upper limit setting unit 42 may be configured to accept the setting of the upper limit of the liquid fertilizer supply amount per line (upper limit of the liquid supply amount).

[0096] (5) A single line is provided with a plurality of containers 3, and a cultivated plant Q is planted in each of the plurality of containers 3. This embodiment is not limited to this, and a configuration in which a single container 3 is provided in one line may also be used. In this case, the imaging device 5 may be configured to image a single cultivated plant Q. Furthermore, even if a single line is provided with a plurality of containers 3, the cultivated plant Q may be planted in the culture soil of only one container 3. In this case, the imaging device 5 may be configured to image a single cultivated plant Q.

[0097] (6) The multiple containers 3 may be configured so that they cannot be moved individually.

[0098] (7) The fixed support portion 2 may not be provided. In this case, the plurality of containers 3 may be arranged on a weed control sheet or a mulch sheet, for example.

[0099] (8) The irrigation control system may be configured without the soil moisture sensor 4 .

[0100] The configurations disclosed in the above-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments, as long as no contradiction occurs. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these, and can be modified as appropriate within the scope of the present invention.

[0101] The present invention is applicable to an irrigation control system for cultivated plants that are planted in culture soil placed in a container.

[0102] 2: Fixed support part 3: Container 5: Imaging device 11: Calculation part (tension coefficient calculation part) 12: Irrigation control part 20: Irrigation device 25A: Liquid fertilizer tank (top-dressing part) 25B: Liquid fertilizer tank (top-dressing part) 42: Upper limit setting part Q: Cultivated plant R: Imaging range

Claims

1. An irrigation control system comprising: a container containing culture soil; an irrigation device that irrigates cultivated plants planted in the culture soil placed in the container; an imaging device that images the cultivated plants; a tension coefficient calculation unit that calculates a tension coefficient that indicates the tension of branches and leaves; and an irrigation control unit that controls the operation of the irrigation device based on the tension coefficient.

2. An irrigation control system as described in claim 1, wherein a plurality of the containers are provided, and a plurality of the cultivated plants planted in the culture soil of each of the plurality of containers are located within the imaging range of the imaging device.

3. The irrigation control system according to claim 2, wherein the plurality of containers are configured to be individually movable.

4. The irrigation control system according to claim 3, further comprising fixed supports for individually mounting and supporting the plurality of movable containers.

5. An irrigation control system according to any one of claims 1 to 4, wherein the container is configured to allow water to pass through but not allow roots of the cultivated plants to pass through.

6. An irrigation control system as described in any one of claims 1 to 5, comprising: a top dressing section provided in the irrigation device that can supply nitrogen to be mixed into the irrigation water; and an upper limit setting section that sets an upper limit for the amount of nitrogen supplied by the irrigation device.

7. The irrigation control system according to claim 6, wherein the upper limit of the supply amount is the supply amount per day.

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