Irrigation system and control device

Abstract

To provide an irrigation system and a control device which are capable of adjusting a splash distance from distribution tubes during irrigation.SOLUTION: In an irrigation system 10, each environment of a plurality of divided areas in a farm field 20 is individually monitored by monitoring parts 300 corresponding to each divided area. Supply of irrigation in each divided area is individually controlled by the corresponding monitoring parts 300 and water supply valves 152. The irrigation system 10 is equipped with a plurality of distribution tubes 136 which are provided for a farm field 20 which raises plants, and on which through-holes for sprinkling irrigation onto the farm field 20 are formed. The irrigation system 10 is equipped with the water supply valves 152 which control the pressure of irrigation flowing down to the distribution tubes 136. A microcomputer 330 of the monitoring part 300 controls a valve opening degree of the water supply valve 152 to control a splash distance of irrigation emitted from the distribution tubes 136 via the through-holes.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The disclosure herein relates to an irrigation system and control device for controlling the supply of irrigation water to a field. [Background technology]

[0002] Patent Document 1 discloses an irrigation system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 016684 Summary of the Invention [Problem to be solved by the invention]

[0004] According to Patent Document 1, the supply and stop of irrigation from the drip tube is controlled by opening and closing a valve that allows or blocks the supply of water to the drip tube. In this way, when the valve is open, water seeps out of the drip tube and irrigates the soil near the tube. However, it is not possible to appropriately splash water onto the soil at a desired location away from the drip tube. For this reason, the irrigation system of Patent Document 1 has room for improvement in terms of accurately providing irrigation to the location where it is needed.

[0005] An object of the disclosure in this specification is to provide an irrigation system and control device that can adjust the distance water is thrown from a distribution tube during irrigation. [Means for solving the problem]

[0006] The various aspects disclosed in this specification employ different technical means to achieve their respective objectives. The reference symbols in parentheses in the claims and in this section are merely examples showing the corresponding relationship with the specific means described in the embodiments described below as one aspect, and do not limit the technical scope.

[0007] One of the disclosed irrigation systems is provided in a field (20) in which plants (30) are grown, and includes a distribution tube (136) having a plurality of through holes for spraying irrigation water to the field, a water supply valve (152) for controlling the pressure of the irrigation water flowing down the distribution tube, and a control device (330) for controlling the valve opening of the water supply valve to control the distance that the irrigation water travels as it is released from the distribution tube through the through holes.

[0008] According to this irrigation system, the distance that the irrigation water discharged from the distribution tube is controlled by controlling the valve opening of the water supply valve to control the irrigation pressure. Therefore, this irrigation system can perform accurate irrigation by adjusting the distance that the water is discharged from the distribution tube. The irrigation system can discharge water to the necessary places in the soil according to the growth of the plants, and can reduce wasteful irrigation and achieve water conservation.

[0009] One of the disclosed control devices is a control device that controls the travel distance of irrigation water supplied to a field (20) in which plants (30) are grown from a distribution tube (136) having a plurality of through holes formed therein, and includes a calculation unit (334) that determines the valve opening degree of a water supply valve (152) that controls the pressure of the irrigation water flowing down the distribution tube, and an output unit (332) that outputs a control signal to the water supply valve that controls the valve opening degree in order to control the travel distance of the irrigation water released from the distribution tube through the through holes.

[0010] According to this control device, the calculation unit determines the valve opening, and the output unit outputs a control signal to the water supply valve to control the valve opening in order to control the distance the irrigation water will fly. This makes it possible to control the distance the irrigation water will fly from the distribution tube. Therefore, this control device can perform accurate irrigation by adjusting the distance the water will fly from the distribution tube. This control device can direct water to the necessary places in the soil in accordance with the growth of the plants, reducing wasteful irrigation and realizing water conservation. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a conceptual diagram showing an irrigation system of a first embodiment installed in a farm field. [Diagram 2] FIG. 2 is a partial view showing the water supply pipe and the pipe module. [Diagram 3] FIG. 1 is a block diagram of an irrigation system. [Figure 4] FIG. 2 is a block diagram showing a monitoring unit. [Diagram 5] FIG. [Figure 6] 11 is a flowchart illustrating a sensor process. [Figure 7] 13 is a flowchart illustrating an update process. [Figure 8] 13 is a flowchart illustrating a monitoring process. [Figure 9] 10 is a flowchart for explaining a water supply process. [Figure 10] 11 is a flowchart for explaining a watering process. [Figure 11] 13 is a flowchart illustrating a user update process. [Figure 12] 13 is a flowchart illustrating a forced update process. [Figure 13] FIG. 1 is a cross-sectional view showing a valve device that can be used as a water supply valve. [Figure 14] 3 is a diagram showing a configuration of a drive unit included in the valve device. FIG. [Figure 15] FIG. 2 is a perspective view showing a valve provided in the valve device. [Figure 16] 4 is a graph showing the relationship between the rotation angle and the flow rate in a valve device. [Figure 17] FIG. 11 is a block diagram showing a monitoring unit according to a second embodiment. [Figure 18] 10 is a flowchart showing the operation of a water supply valve according to a second embodiment. [Figure 19] FIG. 11 is a diagram for explaining an example of irrigation according to the second embodiment. [Figure 20] 10 is a flowchart showing the operation of a water supply valve according to a third embodiment. [Figure 21] 10 is a flowchart showing the operation of a water supply valve according to a fourth embodiment. [Figure 22] 13 is a flowchart showing the operation of a water supply valve according to a fifth embodiment. [Figure 23] FIG. 13 is a diagram for explaining irrigation according to the fifth embodiment. [Figure 24] FIG. 13 is a diagram showing the relationship between the valve opening and the soil moisture content. [Diagram 25] FIG. 13 is a diagram showing the relationship between the valve opening and the water flying distance during ramp operation. [Figure 26] FIG. 13 is a diagram showing the relationship between the valve opening and the water flying distance in step operation. [Figure 27] 1 is a diagram showing the positional relationship between a distribution tube, a water supply valve, and a water pressure sensor. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a number of embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, other embodiments described previously may be applied to other parts of the configuration. In addition to combinations of parts that are specifically indicated as being possible in each embodiment, it is also possible to partially combine embodiments even if not indicated, as long as there is no particular problem with the combination.

[0013] First Embodiment A first embodiment disclosing an example of an irrigation system will be described with reference to Figs. 1 to 16. In the following, three directions that are mutually orthogonal are referred to as the x-direction, y-direction, and z-direction. In this specification, the plane defined by the x-direction and y-direction is along the horizontal plane. The z-direction is along the vertical direction. In the drawings, the description of "direction" is omitted, and only x, y, and z are used.

[0014] <Field> The irrigation system 10 is applied to an outdoor field 20 cultivated on a hill or plain. As shown in FIG. 1, an embodiment in which the irrigation system 10 is applied to a field 20 cultivated on a plain will be described. The field 20 has an area of ​​several tens of square meters to several thousand square kilometers. The field 20 has a plurality of growing areas such as ridges extending in the x direction. These multiple growing areas extending in the x direction are arranged at intervals in the y direction. Seeds or seedlings of plants 30 are buried in each of the multiple growing areas. Examples of the plants 30 include grapes, corn, almonds, raspberries, leafy vegetables, and cotton.

[0015] A plurality of plants 30 are grown in one growing area. The plurality of plants 30 are lined up in a row in the x direction. In the following, the plurality of plants 30 lined up in a row in the x direction are referred to as a group of plants 31. In the field 20, the plurality of groups of plants 31 are lined up at intervals in the y direction. The minimum distance between the plurality of groups of plants 31 in the y direction is longer than the minimum distance between the plurality of plants 30 included in one group of plants 31 in the x direction. The distance between the plurality of groups of plants 31 in the y direction is changed in various ways depending on the type of plant 30 growing therein and the undulation and climate of the field 20. The distance between the plurality of groups of plants 31 in the y direction is about 1 m to 10 m. Even if the branches and leaves of the plants 30 grow thick in the y direction, at least a width sufficient for a person to move between two groups of plants 31 in the x direction is ensured.

[0016] <Irrigation system> The irrigation system 10 includes a water supply device 100 and a control device 200. The water supply device 100 supplies irrigation water to plants 30 in a field 20. The control device 200 determines the time and amount of irrigation water supplied from the water supply device 100 to the plants 30 during a watering period. The control device 200 determines the irrigation schedule for the water supply device 100.

[0017] <Water supply device> The water supply device 100 has a pump 110, a water supply pipe 130, and a piping module 150. The pump 110 supplies irrigation water to the water supply pipe 130. The piping module 150 controls the discharge amount of the irrigation water supplied to the water supply pipe 130.

[0018] <Pump> The pump 110 is in a constant operating state. Alternatively, the pump 110 is in a daytime operating state. The pump 110 pumps out irrigation water stored in a tank or a reservoir, and supplies it to the water supply pipe 130. The irrigation water may be well water, river water, rainwater, city water, or the like. As described below, the water supply pipe 130 is provided with a plurality of water supply valves 152. When each of the plurality of water supply valves 152 is in a closed state and there is no leakage of irrigation water from the water supply pipe 130, the water supply pipe 130 is filled with irrigation water. At this time, the water pressure in the water supply pipe 130 becomes a value (also called pump pressure) that depends on the discharge capacity of the pump 110. When the water supply valve 152 changes from a closed state to an open state, irrigation water is discharged from the water supply pipe 130 to the field 20. When the discharge amount of irrigation water becomes stable on a time average basis, the water pressure in the water supply pipe 130 becomes a flow pressure that is lower than the pump pressure.

[0019] <Water supply piping> The water supply pipe 130 includes a main pipe 131 and a supply pipe 132. The main pipe 131 is connected to the pump 110. The supply pipe 132 is connected to the main pipe 131. The pump 110 supplies irrigation water from the main pipe 131 to the supply pipe 132. The irrigation water is supplied to the field 20 from the supply pipe 132.

[0020] <Main piping> The main pipe 131 includes a vertical pipe 133 and a horizontal pipe 134. The vertical pipe 133 extends in the y direction. The horizontal pipe 134 extends in the x direction. The vertical pipe 133 and the horizontal pipe 134 are connected to each other. Due to this configuration, irrigation water flows in the y direction and the x direction within the main pipe 131. In the example shown in FIG. 1, one vertical pipe 133 is connected to one pump 110. A plurality of horizontal pipes 134 extend in the x direction from the vertical pipe 133 extending in the y direction. The position of the horizontal pipe 134 in the z direction is set so as to be farther from the ground than the top of the mature plant 30.

[0021] 1 is merely an example. The number of pumps 110 and vertical pipes 133 provided in the farm field 20, the number of vertical pipes 133 connected to one pump 110, the number of vertical pipes 133 connected to one horizontal pipe 134, and the positions of the horizontal pipes 134 and the vertical pipes 133 in the z direction are not particularly limited.

[0022] The multiple horizontal pipes 134 are lined up at a distance in the y direction. The shortest distance between the multiple horizontal pipes 134 in the y direction is equal to the shortest distance between the multiple groups of plants 31 in the y direction. One of the multiple horizontal pipes 134 is provided in one of the multiple groups of plants 31. The horizontal pipe 134 extends along the direction in which the multiple plants 30 included in the group of plants 31 are lined up. The supply pipe 132 is connected to this horizontal pipe 134.

[0023] <Supply piping> A plurality of supply pipes 132 are connected to one horizontal pipe 134. The plurality of supply pipes 132 connected to one horizontal pipe 134 are arranged in a line at a distance in the x direction. As shown in FIG. 2, the supply pipes 132 include a connecting pipe 135 and a distribution tube 136. The connecting pipe 135 extends downward in the z direction from the horizontal pipe 134. Two connecting ports that open in the x direction are formed at the tip side of the connecting pipe 135. The distribution tubes 136 are connected to these two connecting ports.

[0024] The distribution tube 136 includes a first distribution tube 136a connected to one of the two connection ports and a second distribution tube 136b connected to the other of the two connection ports. The first distribution tube 136a and the second distribution tube 136b extend in opposite directions from the connection position with the connection pipe 135 in the x direction.

[0025] Each of the first distribution tube 136a and the second distribution tube 136b has a plurality of through holes that communicate between the inside of the tube, through which the irrigation water flows, and the outside. The plurality of through holes are arranged in a line at a predetermined interval in the axial direction of the tube in each tube. The through holes may also be arranged in a line at a predetermined interval in the circumferential direction of the tube in each tube.

[0026] The spacing between the multiple through holes in the axial direction (e.g., x direction) is equal to the spacing between the multiple plants 30 in the x direction. In the example shown in Fig. 2, each of the first distribution tube 136a and the second distribution tube 136b has three through holes lined up in the axial direction. The spacing between the multiple through holes and the spacing between the multiple plants 30 may be different. The number of through holes formed in each tube is not limited to three.

[0027] <Flow of irrigation water> The irrigation water supplied to the vertical pipe 133 by the pump 110 flows in the y direction inside the vertical pipe 133. This irrigation water is supplied to each of the multiple horizontal pipes 134 connected to the vertical pipe 133. The irrigation water flows in the x direction inside each of the multiple horizontal pipes 134. The irrigation water flowing inside the horizontal pipes 134 flows down into the distribution tube 136 via the connecting pipe 135. The irrigation water is discharged from each through-hole in each of the first distribution tube 136a and the second distribution tube 136b, and is supplied to the plant 30.

[0028] 1, the first distribution tube 136a and the second distribution tube 136b are each located closer to the ground of the field 20 than the apex of the plant 30 in the height direction. The irrigation water supplied from the through holes of the first distribution tube 136a and the second distribution tube 136b is mainly supplied to the trunk and the root of the plant 30.

[0029] The through-holes are preferably provided at a position higher than the portion of each tube that faces the ground, so that the irrigation water discharged from the through-holes at such a position spreads in a radial direction relative to the central axis of the tube, and can be sprayed at a position distant from the tube.

[0030] <Piping module> 2, the piping module 150 is provided on the supply piping 132. The piping module 150 has a storage box 151, a water supply valve 152, and a water pressure sensor 153. The water supply valve 152 and the water pressure sensor 153 are stored inside the storage box 151.

[0031] <Water supply valve>, The water supply valve 152 is provided in the connecting pipe 135 at a position close to each of the first distribution tube 136a and the second distribution tube 136b. All of the through holes are provided between the water supply valve 152 and the tip portion of the first distribution tube 136a and the second distribution tube 136b that is separated from the connecting pipe 135.

[0032] When the water supply valve 152 is in the open state, the connecting pipe 135 and the through hole are in communication with each other. This allows irrigation water to be discharged from the through hole. Conversely, when the water supply valve 152 is in the closed state, communication between the connecting pipe 135 and the through hole is blocked. This stops the discharge of irrigation water from the through hole.

[0033] The water supply valve 152 provided on the first distribution tube 136a and the water supply valve 152 provided on the second distribution tube 136b are independently controlled in opening degree by the control device 200. By such opening degree control, the discharge of irrigation water from the through hole of the first distribution tube 136a and the discharge of irrigation water from the through hole of the second distribution tube 136b are independently controlled.

[0034] The control device 200 arbitrarily controls the valve opening of the water supply valve 152 between a predetermined opening and full opening. The predetermined opening is set to a value including a slightly open opening or 0%, i.e., a fully closed opening. The control device 200 controls the discharge flow rate or discharge flow velocity per unit time discharged from each through-hole by controlling the valve opening of the water supply valve 152. By this control, the control device 200 can control the water flight distance, which is the distance at which the irrigation water discharged from the distribution tube 136 lands away from the distribution tube 136. The water flight distance is the distance between the distribution tube 136 and the soil landing point of the irrigation water that has flown out of the distribution tube 136 through the through-hole. This technology for controlling the water flight distance allows efficient irrigation to be performed in places that need irrigation, which also contributes to water conservation.

[0035] The control device 200 determines the irrigation water flight distance based on the type of plant 30 to which irrigation water is to be supplied, the range of the till layer in the field 20, and the like. The control device 200 controls the valve opening of the water supply valve 152 so as to obtain the determined water flight distance. For example, the valve opening of the water supply valve 152 is controlled to increase the water flight distance when the plant 30 has wide roots or the till layer is shallow and wide. The valve opening of the water supply valve 152 is also controlled to reduce the water flight distance when the plant 30 has deep roots or the till layer is located near the distribution tube 136. The water flight distance can be rephrased as the irrigation distance.

[0036] <Water pressure sensor> The water pressure sensor 153 is provided in the vicinity of the portion where the first distribution tube 136a and the second distribution tube 136b are connected in the connecting pipe 135. Each water pressure sensor 153 detects the water pressure in the connecting pipe 135. The water pressure detected by the water pressure sensor 153 is output to the control device 200. The water pressure sensor 153 may be provided between the connecting portion of the first distribution tube 136a with the connecting pipe 135 and the water supply valve 152, or between the connecting portion of the second distribution tube 136b with the connecting pipe 135 and the water supply valve 152. The water pressure sensor 153 may be provided in the vicinity of the connecting portion of the connecting pipe 135 with the horizontal pipe 134. The water pressure sensor 153 may be located on the horizontal pipe 134 side of the water supply valve 152 in the flow path of the irrigation water in the supply pipe 132.

[0037] When the water supply valve 152 is closed and the connecting pipe 135 is filled with irrigation water, the pump pressure is detected by the water pressure sensor 153. When the water supply valve 152 changes from closed to open, irrigation water is discharged from the distribution tube 136. When the time-averaged amount of irrigation water discharged stabilizes, the flow pressure is detected by the water pressure sensor 153. When the water supply valve 152 changes from open to closed, the discharge of irrigation water from the water supply pipe 130 stops. The water pressure in the water supply pipe 130 gradually recovers from the flow pressure to the pump pressure. The water pressure sensor 153 detects the water pressure during the transitional period when the water pressure gradually recovers from the flow pressure to the pump pressure.

[0038] If a break occurs in the water supply pipe 130 or the water supply valve 152 and irrigation water leaks from the broken part, the water pressure detected by the water pressure sensor 153 will decrease. This makes it possible to detect whether or not a break has occurred. This break detection process is executed by the control device 200.

[0039] <Control device> 1 and 3, the control device 200 includes a monitoring unit 300, an integrated communication unit 400, an information storage unit 500, and an integrated calculation unit 600. In the drawings, the integrated communication unit 400 is denoted as ICD. The control device 200 has a plurality of monitoring units 300. Each of the plurality of monitoring units 300 corresponds to a predetermined divided area in the farm field 20. One monitoring unit 300 is provided corresponding to one piping module 150, for example. The monitoring unit 300 and the piping module 150 are electrically connected to each other.

[0040] The water pressure detected by the water pressure sensor 153 is input to the monitoring unit 300. The monitoring unit 300 detects an environmental value, which is a physical quantity related to the environment of the farm field 20. Each of the multiple monitoring units 300 outputs the water pressure and the environmental value to the integrated communication unit 400 by wireless communication.

[0041] The integrated communication unit 400 outputs the water pressure and environmental values ​​input from each monitoring unit 300 to the information storage unit 500 via wireless communication. The information storage unit 500 stores the water pressure and environmental values. An example of the information storage unit 500 is a so-called cloud. The integrated calculation unit 600 reads out various information such as the water pressure and environmental values ​​stored in the information storage unit 500. The integrated calculation unit 600 appropriately processes the read out information and displays the information and processing results on a monitor 700 of the user's smartphone or personal computer.

[0042] The integrated calculation unit 600 is included in a user's smartphone or personal computer. The integrated calculation unit 600 has an information processing calculation device 610, a memory 620, and a communication device 630. In the drawings, the information processing calculation device 610 is represented as IPCE, the memory 620 as MM, and the communication device 630 as CD. The information processing calculation device 610 includes a processor. The information processing calculation device 610 performs calculation processing related to irrigation processing. This function is realized by downloading an irrigation application program to the information processing calculation device 610.

[0043] The memory 620 is a non-transient substantial storage medium that non-temporarily stores various programs and various information that can be read by a computer or a processor. The memory 620 has a volatile memory and a non-volatile memory. The memory 620 stores various information input to the communication device 630 and the processing results of the information processing device 610. The information processing device 610 executes various arithmetic processes using the information stored in the memory 620.

[0044] The communication device 630 has a wireless communication function. The communication device 630 converts a received wireless signal into an electric signal and outputs it to the information processing device 610. The communication device 630 outputs the processing result of the information processing device 610 as a wireless signal. Hereinafter, the technical content of this embodiment will be described using the integrated calculation unit 600 as a general term without distinguishing between the information processing device 610, the memory 620, and the communication device 630. The information processing device 610 corresponds to the processing unit.

[0045] A user inputs user instructions related to irrigation treatment and irrigation schedules to the integrated calculation unit 600 using an input device 800 such as a touch panel or a keyboard. The integrated calculation unit 600 outputs irrigation treatment commands and determines the irrigation schedule based on the user instructions and various information read from the information storage unit 500. If there are no instructions from the user, the integrated calculation unit 600 automatically determines the irrigation schedule based on various information.

[0046] When the integrated calculation unit 600 detects an irrigation processing command or determines that it is time to start supplying irrigation water in the irrigation schedule, it outputs an instruction signal to the information storage unit 500 to control the water supply valve 152. This instruction signal is input from the information storage unit 500 to the monitoring unit 300 via the integrated communication unit 400. The monitoring unit 300 controls whether to output a water supply signal to the water supply valve 152 based on the instruction signal. This controls the open / close state of the water supply valve 152. As a result, the supply of irrigation water to the field 20 is controlled. At least one of the instruction signal and the water supply signal corresponds to a control signal.

[0047] <Divided area> As shown in Fig. 1, one monitoring unit 300 is provided for each supply pipe 132. As shown in Fig. 3 as an example, the multiple monitoring units 300, together with the water supply valves 152 and water pressure sensors 153 provided in the multiple piping modules 150, are arranged in a matrix in the field 20 with the x direction as the row direction and the y direction as the column direction.

[0048] With this configuration, the environment of each of the multiple divided areas separated by the row and column directions is monitored individually by the monitoring unit 300 corresponding to each divided area. Furthermore, the supply of irrigation water to each of the multiple divided areas is individually controlled by the corresponding monitoring unit 300 and piping module 150.

[0049] <Monitoring section> 3 and 4, the monitoring unit 300 has an environmental sensor 310 and a control unit 320. The water supply valve 152 and the water pressure sensor 153 of the piping module 150 are electrically connected to the control unit 320. In the drawings, the environmental sensor 310 is represented as ES, the water supply valve 152 as WB, and the water pressure sensor 153 as WPS.

[0050] The multiple environmental sensors 310 are arranged in a matrix in the farm field 20 together with the piping module 150. Each environmental sensor 310 detects an environmental value for each of the multiple divided areas. Each water pressure sensor 153 detects the water pressure for each of the multiple divided areas. The detected environmental value and water pressure for each of the multiple divided areas are stored in the information storage unit 500.

[0051] 4, the control unit 320 includes a microcomputer 330, a communication unit 340, an RTC 350, and a power generation unit 360. The microcomputer is an abbreviation for microcomputer. The RTC is an abbreviation for Real Time Clock. In the drawing, the communication unit 340 is represented as CDP.

[0052] Environmental values ​​and water pressure are input to microcomputer 330. Microcomputer 330 outputs these environmental values ​​and water pressure to integrated communication unit 400 via communication unit 340. An instruction signal is input to microcomputer 330 from integrated communication unit 400. Microcomputer 330 outputs a water supply signal to water supply valve 152 based on this instruction signal. Microcomputer 330 corresponds to an arithmetic processing unit. Microcomputer 330 is a control device that controls the operation of water supply valve 152.

[0053] The microcomputer 330 has a sleep mode and a normal mode as operation modes. In the sleep mode, the microcomputer 330 stops processing. In the normal mode, the microcomputer 330 executes processing. The normal mode consumes more power than the sleep mode.

[0054] The communication unit 340 performs wireless communication with the integrated communication unit 400. The communication unit 340 outputs the electrical signal output from the microcomputer 330 as a wireless signal to the integrated communication unit 400. At the same time, the communication unit 340 receives the wireless signal output from the integrated communication unit 400 and converts it into an electrical signal. The communication unit 340 outputs the electrical signal to the microcomputer 330. If the electrical signal includes an instruction signal, the microcomputer 330 switches from the sleep mode to the normal mode.

[0055] The RTC 350 has a clock function that keeps time and a timer function that measures time. When a preset time arrives or a preset time has elapsed, the RTC 350 outputs a wake-up signal to the microcomputer 330. When this wake-up signal is input to the microcomputer 330 in the sleep mode, the microcomputer 330 switches from the sleep mode to the normal mode.

[0056] The power generation unit 360 converts the light energy obtained by the solar cell into electrical energy. The power generation unit 360 functions as a power supply source for the monitoring unit 300. Power is constantly supplied from the power generation unit 360 to the RTC 350. This prevents the clock function and timer function of the RTC 350 from being impaired.

[0057] <Environmental sensor> One of the environmental values ​​that is expected to differ for each divided area of ​​the field 20 is soil moisture content. The environmental sensor 310 detects the environmental value in the corresponding divided area. The environmental sensor 310 includes a soil sensor 311 that detects the soil moisture content, etc. The multiple soil sensors 311 detect the soil moisture content in the multiple divided areas arranged in the field 20. In the drawings, the soil sensor 311 is represented as SMS.

[0058] The amount of solar radiation is one of the environmental values ​​that is expected to differ for each divided area depending on the undulations of the field 20 and the growth conditions of the plants 30. In this specification, each environmental sensor 310 is equipped with a solar radiation sensor 312 that detects the amount of solar radiation. The multiple solar radiation sensors 312 detect the amount of solar radiation in the multiple divided areas of the field 20. In the drawings, the solar radiation sensor 312 is denoted as SRS.

[0059] The soil moisture distribution and solar radiation distribution in the field 20 are displayed as a map on the monitor 700 by arranging the soil moisture amounts and solar radiation amounts detected in the multiple divided areas in a matrix. Similarly, the water pressure distribution in the water supply pipes 130 in the field 20 is displayed as a map on the monitor 700 by arranging the water pressures detected by the multiple water pressure sensors 153 in a matrix. Such map display processing is performed by the integrated calculation unit 600.

[0060] The environmental values ​​in the field 20 include the amount of rainfall, temperature, humidity, air pressure, and wind volume. Sensors for detecting these environmental values ​​are a rain sensor 313, a temperature sensor 314, a humidity sensor 315, an air pressure sensor 316, and a wind sensor 317. These are included in at least one environmental sensor 310 of the multiple monitoring units 300.

[0061] The environmental sensor 310 of the monitoring unit 300 includes various sensors that detect these environmental values ​​of the entire field 20. An example of the environmental sensor 310 is shown in Fig. 4. In the drawing, the rain sensor 313 is represented as RS, the temperature sensor 314 as TS, the humidity sensor 315 as MS, the air pressure sensor 316 as PS, and the wind sensor 317 as WS. The wind sensor 317 may be configured to detect not only the air volume but also the wind direction. A configuration may be adopted in which at least one of the rain sensor 313, temperature sensor 314, humidity sensor 315, air pressure sensor 316, and wind sensor 317 is arranged in a matrix in the field 20.

[0062] This configuration is effective when the amount of rainfall, temperature, humidity, air pressure, and wind volume are likely to change significantly for each divided area because the field 20 is large, has steep undulations, or experiences drastic weather changes in the field 20. By arranging the amount of rainfall, temperature, humidity, air pressure, and wind volume detected by these sensors in a matrix, it becomes possible to display these environmental values ​​as a map on the monitor 700. The outputs of these sensors are output to the communication unit 340 via the integrated communication unit 400. At the same time, the outputs of these sensors are stored in the information storage unit 500 via the integrated communication unit 400.

[0063] <Soil moisture content> Among the various environmental values ​​described above, the environmental values ​​controlled by the irrigation system 10 include soil moisture content. The irrigation system 10 controls the time and amount of irrigation water supply for each divided area. In this way, the soil moisture content for each divided area is controlled individually.

[0064] The plant 30 has its roots in the till layer of the field 20. The growth of the plant 30 depends on the amount of water contained in the soil of this till layer (also called the soil moisture content). If the soil moisture content exceeds the growth inhibition moisture point, the plant 30 will develop disease. If the soil moisture content falls below the permanent wilting point, the plant 30 will not recover from wilting. The growth inhibition moisture point and the permanent wilting point differ depending on the type of plant 30, but their values ​​are known. These values ​​are stored in the information storage unit 500.

[0065] The current value of the soil moisture content is detected by the soil sensor 311. Physical quantities related to the soil moisture content include the soil moisture tension (pF value) and the soil dielectric constant (ε). The soil sensor 311 in this specification detects the pF value.

[0066] The soil moisture content in the plowed soil layer increases or decreases due to environmental changes in the field 20. When rain falls on the field 20, the soil moisture content increases. When water evaporates from the plowed soil layer, the soil moisture content decreases. Also, when the plants 30 absorb the moisture or when the water permeates below the plowed soil layer, the soil moisture content decreases. The amount of rain falling on the plowed soil layer (rainfall amount) is detected by the rain sensor 313. The amount of moisture evaporating from the plowed soil layer (evaporation amount) depends on the amount of solar radiation, temperature, humidity, and wind volume. These are detected by the solar radiation sensor 312, the temperature sensor 314, the humidity sensor 315, and the wind sensor 317.

[0067] The amount of water absorbed by the plant 30 per unit time can be estimated in advance based on the type of plant 30. The amount of water that permeates below the plow soil layer per unit time can be estimated in advance based on the water retention capacity of the soil. These estimated values ​​are stored in the information storage unit 500.

[0068] As described above, the environmental sensor 310 detects the current value of the soil moisture content in the plowed soil layer, the increase from the current value of the soil moisture content in the plowed soil layer due to environmental changes, and the predicted value relating to the predicted decrease. These are stored as environmental values ​​in the information storage unit 500. The information storage unit 500 stores the growth inhibition moisture point and permanent wilting point of the plant 30, the amount of water absorbed by the plant 30 per unit time, and the moisture retention capacity of the soil. The above-mentioned instructions from the user (user instructions) are stored in the information storage unit 500. In this way, the information storage unit 500 stores various information for determining the watering schedule.

[0069] <Microcomputer> 4, the microcomputer 330 includes an acquisition unit 331, a signal output unit 332, a storage unit 333, and a processing unit 334. In the drawing, the acquisition unit 331 is represented as AD, the signal output unit 332 as SOU, the storage unit 333 as MU, and the processing unit 334 as PU.

[0070] An environmental value detected by the environmental sensor 310 is input to the acquisition unit 331. A water pressure detected by the water pressure sensor 153 is input to the acquisition unit 331. The acquisition unit 331 is electrically connected to each of the environmental sensor 310 and the water pressure sensor 153. The wire 160 shown in FIG. 1 is an example of a wire connecting the acquisition unit 331 and the soil sensor 311, and a wire connecting the acquisition unit 331 and the water pressure sensor 153.

[0071] The signal output unit 332 is electrically connected to the water supply valve 152. A control signal (water supply signal) for controlling the valve opening degree of the water supply valve 152 is output from the signal output unit 332 to the water supply valve 152. When no water supply signal is input, the water supply valve 152 is in a closed state. When a water supply signal is input, the water supply valve 152 is in an open state.

[0072] The memory unit 333 is a non-transient substantial storage medium that non-temporarily stores programs and data that can be read by a computer or a processor. The memory unit 333 has a volatile memory and a non-volatile memory. The memory unit 333 stores a program for the processing unit 334 to execute arithmetic processing. This program includes at least a part of the above-mentioned irrigation application program. The memory unit 333 temporarily stores data when the processing unit 334 executes arithmetic processing. The memory unit 333 stores various data input to the acquisition unit 331 and the communication unit 340, respectively, and the acquisition times of the various data.

[0073] When a wake-up signal is input from the RTC 350, the processing unit 334 goes from the sleep mode to the normal mode. In the normal mode, the processing unit 334 reads the programs and various data stored in the memory unit 333 and executes arithmetic processing. This arithmetic processing includes the calculation of the valve opening required for the water splashed through the through-hole of the distribution tube 136 to reach the desired irrigation position. The processing unit 334 corresponds to a calculation unit.

[0074] The processing unit 334 reads out from the RTC 350 the acquisition times of the various sensor signals input to the acquisition unit 331 and the instruction signal input to the communication unit 340. The processing unit 334 causes the storage unit 333 to store the instruction signal and the acquisition time.

[0075] The processing unit 334 stores the environmental values ​​and water pressure input from the environmental sensor 310 and the water pressure sensor 153, and the times at which they were acquired, in the information storage unit 500 via the communication unit 340 and the integrated communication unit 400. The processing unit 334 outputs a water supply signal to the water supply valve 152 via the signal output unit 332, based on an instruction signal input from the integrated calculation unit 600 via the information storage unit 500, the integrated communication unit 400, and the communication unit 340.

[0076] <Communications Department> The communication unit 340 converts the electrical signal input from the processing unit 334 into a wireless signal. The communication unit 340 outputs the wireless signal to the integrated communication unit 400. The communication unit 340 converts the wireless signal output from the integrated communication unit 400 into an electrical signal. The communication unit 340 outputs the electrical signal to the processing unit 334.

[0077] The wireless signal output by communication unit 340 includes address 341 and data 342, which are simply shown in Fig. 5. In the drawing, address 341 is represented as ADD, and data 342 is represented as DAT.

[0078] 3, wireless signals are transmitted and received between the multiple communication units 340 and the integrated communication unit 400. An address 341 included in the wireless signal is an identification code indicating which of the multiple communication units 340 the signal was output from. In other words, the address included in the wireless signal is an identification code indicating which of the multiple processing units 334 the signal was output from. A unique address 341 is stored in each of the multiple storage units 333.

[0079] The wireless signal output from the integrated communication unit 400 also contains an address 341. The data 342 of this wireless signal contains an instruction signal. This wireless signal is received by each of the multiple communication units 340. This wireless signal is converted into an electrical signal by each of the multiple communication units 340. This electrical signal is then input to each of the multiple processing units 334. Of the multiple processing units 334, only the processing unit 334 having the same address 341 as the address 341 contained in the electrical signal executes arithmetic processing based on the electrical signal.

[0080] As described later, the microcomputer 330 operates intermittently by alternately switching between a sleep mode and a normal mode. For this reason, wireless communication between the communication unit 340 and the integrated communication unit 400 is not performed frequently. The time intervals at which wireless communication is performed between the communication unit 340 and the integrated communication unit 400 are long. This makes it possible to increase the amount of data that can be included in the data 342 in one wireless communication.

[0081] <Power Generation Division> The power generation unit 360 includes a solar cell 361, a power storage unit 362, a current sensor 363, and a power sensor 364. In the drawings, the solar cell 361 is represented as SB, the power storage unit 362 as ESU, the current sensor 363 as CS, and the power sensor 364 as PS. The solar cell 361 converts light energy into electrical energy. The power storage unit 362 stores the electrical energy (power). The power stored in the power storage unit 362 is utilized as power to drive the monitoring unit 300.

[0082] Current sensor 363 detects the current output from solar cell 361 to power storage unit 362. Power sensor 364 detects the power output from power storage unit 362. Processing unit 334 stores the detected current value and power value in information storage unit 500 via communication unit 340 and integrated communication unit 400. The driving power of monitoring unit 300 depends on the power generated by power generation unit 360. For this reason, if the amount of light incident on power generation unit 360 is small, the driving power of monitoring unit 300 may be insufficient. To avoid this, microcomputer 330 of monitoring unit 300 performs intermittent driving.

[0083] <rtc> The RTC 350 outputs a wake-up signal to the microcomputer 330 every time the above-mentioned intermittent drive time interval (drive cycle) elapses. This causes the microcomputer 330 to alternate between sleep mode and normal mode. The drive cycle is determined by the integrated calculation unit 600 according to the amount of power stored in the power storage unit 362 (amount of stored power). In other words, the intermittent drive interval is determined by the integrated calculation unit 600 according to the amount of stored power.

[0084] The integrated calculation unit 600 calculates the amount of stored power based on the power stored in the information storage unit 500. The integrated calculation unit 600 sets a longer intermittent drive interval as the amount of stored power decreases. The integrated calculation unit 600 sets a shorter intermittent drive interval as the amount of stored power increases. The integrated calculation unit 600 includes the intermittent drive interval in an instruction signal. When the processing unit 334 of the microcomputer 330 acquires this instruction signal, the processing unit 334 adjusts the intermittent drive interval. The processing unit 334 adjusts the drive cycle of the RTC 350. It is rare for the environment of the field 20 to change drastically in units of a few seconds. For this reason, the intermittent drive interval is set to a unit of tens of seconds to tens of hours. Accordingly, the time interval for wireless communication is also set to a unit of tens of seconds to tens of hours.

[0085] <Driving the irrigation system> In the irrigation system 10, signals are transmitted and received between the multiple monitoring units 300 and the integrated calculation unit 600, and various data are stored in the information storage unit 500. Each of the multiple monitoring units 300 and the integrated calculation unit 600 executes a cycle task that is processed for each drive period, and an event task that is processed suddenly.

[0086] These cycle tasks and event tasks have a processing priority order. When the processing timing of these tasks becomes the same, the event task processing is given priority over the cycle task processing. As cycle tasks, each monitoring unit 300 executes the sensor processing shown in FIG. 6. The integrated calculation unit 600 executes the update processing shown in FIG. 7. As event tasks, each monitoring unit 300 executes the monitoring processing shown in FIG. 8 and the water supply processing shown in FIG. 9. The integrated calculation unit 600 executes the irrigation processing shown in FIG. 10, the user update processing shown in FIG. 11, and the forced update processing shown in FIG. 12.

[0087] The sensor processing and update processing as cycle tasks will be described below with reference to Figures 6 and 7. In each diagram showing a flowchart, the start is indicated by S and the end is indicated by E.

[0088] <Sensor processing> Before the start shown in FIG. 6, the microcomputer 330 of the monitoring unit 300 is in a sleep mode, and a wake-up signal is input from the RTC 350 to the microcomputer 330. This causes the microcomputer 330 to switch from the sleep mode to the normal mode. At the same time, the microcomputer 330 starts executing the sensor processing shown in FIG. 6. This sensor processing is executed at the intermittent drive interval of the microcomputer 330. In step S10, the sensor signals input from the various sensors are acquired, and the acquisition times of the sensor signals are acquired based on the output of the RTC 350. In addition, in step S20, the acquired sensor signals and the acquisition times are stored. In step S30, the sensor signals and the acquisition times as sensor information are output from the communication unit 340 to the integrated communication unit 400 by wireless communication. This sensor information is stored in the information storage unit 500 by the integrated communication unit 400. The microcomputer 330 transitions to a sleep mode and ends the sensor processing.

[0089] <Update process> The integrated calculation unit 600 executes the update process shown in FIG. 7 every time an update period elapses. This update period is approximately the same as the intermittent drive interval of the microcomputer 330. In step S110, various information stored in the information storage unit 500 is read. In the next step S120, the irrigation schedule of each of the multiple monitoring units 300 is updated based on the various information read. The integrated calculation unit 600 also updates the sensor processing in each monitoring unit 300. The integrated calculation unit 600 updates the intermittent drive interval, which corresponds to the timing for executing the sensor processing. The integrated calculation unit 600 holds the updated irrigation schedule and intermittent drive interval itself, and stores them in the information storage unit 500, and ends the update process. As described above, the sensor information, the irrigation schedule, and the intermittent drive interval are updated by the cycle task.

[0090] Next, the monitoring process, water supply process, irrigation process, user update process, and forced update process as event tasks will be described with reference to Fig. 8 to Fig. 12. The monitoring process, water supply process, and irrigation process are each executed during the daytime to avoid exhaustion of the driving power of the monitoring unit 300. Whether or not it is daytime can be determined based on the current time and the amount of solar radiation detected by the solar radiation sensor 312, etc.

[0091] <Monitoring process> 8, the microcomputer 330 of each monitoring unit 300 is in sleep mode. An instruction signal is input to the microcomputer 330 from the integrated calculation unit 600 via wireless communication. As a result, the microcomputer 330 switches from the sleep mode to the normal mode and starts executing the monitoring process shown in FIG.

[0092] In step S210, the input instruction signal and the time of acquisition are stored. In the next step S220, it is determined whether or not the instruction signal includes a water supply instruction to change the water supply valve 152 from a closed state to an open state. If the instruction signal includes a water supply instruction, the process proceeds to step S230. If the instruction signal does not include a water supply instruction, the process proceeds to step S240.

[0093] In step S230, the water supply process shown in Fig. 9 is executed. That is, in step S231, the microcomputer 330 outputs a water supply signal to the water supply valve 152 in accordance with the water supply instruction. In step S232, the microcomputer 330 determines whether or not the water supply time included in the instruction signal has elapsed. If the water supply time has not elapsed, the microcomputer 330 continues to output the water supply signal to the water supply valve 152. If the water supply time has elapsed, the process proceeds to step S233.

[0094] In step S233, the output of the water supply signal is stopped and the water supply process is terminated. In the next step S240, it is determined whether or not the instruction signal includes an instruction to update the intermittent drive interval. If the instruction signal includes an instruction to update the intermittent drive interval, the process proceeds to step S250. If the instruction signal does not include an instruction to update the intermittent drive interval, the process proceeds to step S260. The above-mentioned instruction to update the intermittent drive interval is output as an instruction signal from the integrated calculation unit 600 or the information storage unit 500 to each monitoring unit 300 periodically or irregularly.

[0095] In step S250, the processing unit 334 of the microcomputer 330 adjusts the time interval for outputting a wake-up signal from the RTC 350. In the next step S260, the sensor processing described with reference to FIG. 6 is executed. If the water supply processing in step S230 is executed, the environmental value after irrigation is supplied is detected in step S260. If the water supply processing in step S230 is not executed, the environmental value when irrigation is not being supplied is detected in step S260. This environmental value is stored in the information storage unit 500. After executing the sensor processing, the microcomputer 330 transitions to a sleep mode and ends the monitoring processing.

[0096] <Irrigation treatment> The integrated calculation unit 600 executes the watering process shown in Fig. 10 each time it is time to supply water in the watering schedule of each monitoring unit 300. In step S310, the integrated calculation unit 600 outputs a water supply signal including a water supply instruction to the monitoring unit 300 of the multiple monitoring units 300 that is in the divided area to which water is to be supplied. In the next step S320, the water supply instruction includes the start of output of the water supply signal and the output time of the water supply signal (water supply time). The monitoring unit 300 that receives this water supply instruction executes the monitoring process described based on Fig. 8.

[0097] When the process proceeds to step S320, the integrated calculation unit 600 goes into a standby state until the monitoring process of the monitoring unit 300 ends. When the monitoring process ends, the process proceeds to step S330. The determination as to whether the monitoring process has ended is made, for example, based on whether a time that is expected for the monitoring process to end has elapsed. The determination as to whether the monitoring process has ended can be made by inquiring of the monitoring unit 300. There is no particular limitation on the method of determining whether the monitoring process has ended.

[0098] <User update process> The integrated calculation unit 600 executes the user update process shown in Fig. 11 when a user instruction relating to adjustment of the watering schedule or the intermittent drive interval is input from the input device 800. In step S410, the integrated calculation unit 600 stores the input user instruction in the information storage unit 500. In the next step S420, the update process described with reference to Fig. 7 is executed. As a result, the watering schedule and the intermittent drive interval are updated based on the user instruction.

[0099] <Forced update process> The integrated calculation unit 600 executes the forced update process shown in Fig. 12 when a user instruction related to updating the watering schedule and the intermittent drive interval is input. In step S510, the integrated calculation unit 600 outputs a request signal including a request instruction requesting execution of sensor processing. This request signal is output to the monitoring unit 300 by wireless communication. In step S520, the integrated calculation unit 600 goes into a standby state until the sensor processing of the monitoring unit 300 is completed.

[0100] If the sensor processing has ended, the process proceeds to step S530. The determination as to whether the sensor processing has ended can be made, for example, based on whether the time required for the sensor processing to end has elapsed. Alternatively, the determination can be made by inquiring of the monitoring unit 300 as to whether the sensor processing has ended. There are no particular limitations on the method of determining whether the sensor processing has ended. In step S530, the update process described with reference to FIG. 7 is executed. As a result, the watering schedule and the intermittent drive interval are updated based on various data at the time of the user's update request.

[0101] The monitoring unit 300 judges whether water is coming out of the distribution tube 136 in the water supply process shown in Fig. 9 and the irrigation process shown in Fig. 10, and performs processing according to the judgment result. The monitoring unit 300 judges whether water is being discharged based on the water pressure detected by the water pressure sensor 153. If the monitoring unit 300 judges that the water pressure detected by the water pressure sensor 153 exceeds the abnormal pressure value, it fully closes the water supply valve 152 during irrigation and stops irrigation. The abnormal pressure value is set to a pressure value that is impossible when water is being discharged from the distribution tube 136 or a pressure value when water has nowhere to go and is not released to the outside. The abnormal pressure value is stored in the memory unit 333 in advance.

[0102] When the water pressure exceeds the abnormal pressure value, the monitoring unit 300 performs further irrigation from the adjacent distribution tube 136 adjacent to the distribution tube 136 for which irrigation has been stopped. For example, the adjacent distribution tube 136 is adjacent to the distribution tube 136 for which irrigation has been stopped in a direction perpendicular to the axial direction of the tube. The monitoring unit 300 controls the valve opening of the water supply valve 152 that can supply water to the adjacent distribution tube 136 to a value that provides a water jump distance that reaches the target irrigation position that was intended for the stopped irrigation.

[0103] In this way, when irrigation water is not being released from a distribution tube 136, the control device controls the valve opening of the water supply valve 152 that controls the pressure of irrigation water flowing down to the adjacent distribution tube 136 adjacent to the distribution tube 136 from which irrigation water is not being released. By controlling the valve opening, the control device controls the flight distance of irrigation water released from the adjacent distribution tube 136 so that the irrigation water that was not released reaches the target irrigation position that was intended. This control makes it possible to provide an irrigation system 10 that can eliminate irrigation problems caused by clogging of the piping or distribution tube 136 or a malfunction of the water supply valve 152.

[0104] <Individual irrigation treatment> As described above with reference to Figs. 6 to 12, the integrated calculation unit 600 determines a watering schedule for each of the multiple divided areas. The integrated calculation unit 600 controls the supply of irrigation water based on each irrigation schedule. Although the irrigation schedule for each of the multiple divided areas is determined by the integrated calculation unit 600, a configuration may be adopted in which the supply of irrigation water based on each irrigation schedule is individually controlled by each monitoring unit 300.

[0105] <Independent update> As a further example, a configuration may be adopted in which the watering schedule for each divided area is determined independently by the corresponding monitoring unit 300. In such a configuration, each monitoring unit 300 executes the update process shown in FIG.

[0106] <Weather forecast and irrigation schedule> The information storage unit 500 stores the current soil moisture content value, a predicted decrease in the soil moisture content, and user instructions. The information storage unit 500 stores the growth inhibition moisture point and permanent wilting point of the plant 30, the amount of water absorbed by the plant 30 per unit time, and the soil's moisture retention capacity. In addition to these, the information storage unit 500 stores a weather forecast for the field 20 output and distributed from an external information source 1000. In the drawings, the external information source 1000 is denoted as ESI.

[0107] 7, the integrated calculation unit 600 reads out various information including the weather forecast from the information storage unit 500. The integrated calculation unit 600 determines a watering schedule for each monitoring unit 300 in step S120.

[0108] <Target and Estimated Values> The integrated calculation unit 600 calculates a target value and an estimated value of the soil moisture content when determining the irrigation schedule. The target value of the soil moisture content is, as a matter of course, set to a value between the growth inhibition moisture point and the permanent wilting point. In order to attempt to grow the plant 30 in a healthy manner, the target value of the soil moisture content is set to a value somewhat away from each of the growth inhibition moisture point and the permanent wilting point, which are theoretical values.

[0109] The integration calculation unit 600 sets an upper limit target value on the growth inhibition moisture point side and a lower limit target value on the permanent wilting point side as the target values ​​of the soil moisture content. The integration calculation unit 600 determines the irrigation schedule so that the estimated value of the soil moisture content is between the upper limit target value and the lower limit target value during the irrigation period of the irrigation schedule. Even if it is predicted that the estimated value of the soil moisture content will exceed the upper limit target value due to rainfall, the integration calculation unit 600 determines the irrigation schedule so that the estimated value of the soil moisture content does not exceed the growth inhibition moisture point.

[0110] There is a deviation between the growth inhibition moisture point and the upper target value. This upper deviation range is determined based on the climate of the field 20 while taking into consideration the healthy growth of the plant 30 described above. The climate of the field 20 includes the expected average rainfall amount of the field 20 during the irrigation period of the irrigation schedule and the total rainfall amount predicted by the weather forecast during the irrigation period. The expected average rainfall amount of the field 20 during the irrigation period is stored in the information storage unit 500.

[0111] There is a deviation between the permanent wilting point and the lower limit target value. This lower limit deviation width is determined based on the expected recovery time when a failure occurs in the water supply device 100 and the decrease in soil moisture content per unit time, while also taking into consideration the healthy growth of the plant 30. For example, the lower limit deviation width is determined based on the value obtained by multiplying the recovery time by the decrease in soil moisture content per unit time. The recovery time is stored in the information storage unit 500.

[0112] For example, when a one-week weather forecast is stored in the information storage unit 500 from the external information source 1000, the integrated calculation unit 600 determines an irrigation schedule for the one week. If the weather forecast does not predict any rainfall during this one-week period, the estimated soil moisture content is expected to gradually decrease over time. The decrease in the estimated soil moisture content per unit time is determined based on a predicted decrease in the soil moisture content of the plowed soil layer. For ease of notation, the estimated soil moisture content will be referred to simply as the estimated value below as necessary.

[0113] As described above, the watering schedule is determined based on the estimated soil moisture content based on environmental values ​​and the like, and on the weather forecast. This makes it possible to prevent the soil moisture content in the outdoor divided areas from becoming unsuitable for the plants 30 due to weather changes such as rainfall or dryness. It is also possible to prevent the soil moisture content from exceeding the growth inhibition moisture point or falling below the permanent wilting point.

[0114] The integrated calculation unit 600 determines the target water supply amount so that the estimated value of the soil moisture content does not exceed the upper limit target value lower than the growth inhibition moisture point during any irrigation period of the irrigation schedule. The integrated calculation unit 600 determines the deviation range (upper limit deviation range) between the growth inhibition moisture point and the upper limit target value based on the climate of the field 20, etc. The climate of the field 20 includes the expected average rainfall amount of the field 20 during the irrigation period and the total rainfall amount predicted by the weather forecast during the irrigation period. By setting the upper limit deviation range in this manner, even if there is more rainfall than predicted by the weather forecast after the soil moisture content is brought close to the upper limit target value by the supply of irrigation water, the soil moisture content is prevented from reaching the growth inhibition moisture point.

[0115] The integrated calculation unit 600 determines the target water supply amount so that the estimated value of the soil moisture content in the irrigation schedule does not fall below a lower limit target value higher than the permanent wilting point. The integrated calculation unit 600 determines the deviation width (lower limit deviation width) between the permanent wilting point and the lower limit target value based on the recovery time and the decrease in soil moisture content per unit time. By setting the lower limit deviation width in this manner, even if irrigation water cannot be supplied due to a malfunction of the water supply valve 152 when the soil moisture content is close to the lower limit target value, the soil moisture content can be prevented from reaching the permanent wilting point until the malfunction is restored.

[0116] The integrated calculation unit 600 supplies water at the time when the estimated soil moisture content in the irrigation schedule reaches the lower limit target value. This makes it possible to prevent the soil moisture content from falling below the lower limit target value. The integrated calculation unit 600 differentiates the rainfall forecast time from the time when irrigation water is supplied. This makes it possible to prevent the soil moisture content from increasing excessively even if the amount of rainfall is greater than the rainfall forecast.

[0117] An example of a valve device applicable to the water supply valve 152 will be described below with reference to Figures 13 to 15. This valve device is a so-called rotary type valve device. This valve device has one fluid inlet and three fluid outlets. This valve device is mounted on the irrigation system 10 by connecting the supply pipe 132 to the fluid inlet and connecting the distribution tube 136 to any one of the fluid outlets. Furthermore, a blocking member may be attached to the fluid outlet to which the distribution tube 136 is not connected, thereby blocking the passage.

[0118] 13, the valve device includes a housing 9, a valve 90, a drive unit 70, a drive unit cover 80, etc. The valve device is configured as a ball valve in which the valve 90 rotates about the axis of a shaft 92 to open and close the valve device. In this specification, the direction along the axis of the shaft 92 is referred to as the axial direction DRa, and the direction perpendicular to the axial direction DRa and extending radially from the axial direction DRa is referred to as the radial direction DRr.

[0119] The housing 9 is an accommodating section that accommodates the valve 90. The housing 9 is formed, for example, from a resin member. The housing 9 includes a hollow housing main body 21 that accommodates the valve 90, a pipe member 50 that causes cooling water to flow out from the housing main body 21, and a partition wall section 60 that is attached to the housing main body 21. The housing main body 21 has an approximately rectangular parallelepiped appearance and is formed into a bottomed shape with an opening on the other side in the axial direction DRa. The housing main body 21 has a housing outer wall section 22 that constitutes the outer periphery of the housing main body 21. The housing outer wall section 22 forms a cylindrical valve accommodating space 23 inside the housing main body 21, the valve accommodating space 23 having an axis in the axial direction DRa.

[0120] An inlet port 251 for allowing cooling water to flow into the valve accommodating space 23 is formed in the housing outer wall portion 22. The inlet port 251 is formed with a circular opening, and is connected to the connecting pipe 135. The inlet port 251 corresponds to a fluid inlet portion.

[0121] A pipe member 50 is attached to the housing outer wall portion 22. The housing outer wall portion 22 has a first outlet port 261, a second outlet port 262, and a third outlet port 263 for allowing the cooling water that has flowed into the valve accommodating space 23 via the inlet port 251 to flow out to the pipe member 50. The first outlet port 261, the second outlet port 262, and the third outlet port 263 correspond to a fluid outflow portion.

[0122] A partition wall portion 60 is attached to the housing opening surface 24 of the housing outer wall portion 22. The housing opening surface 24 is disposed on the other side of the housing main body portion 21 in the axial direction DRa. The housing opening surface 24 has a housing opening 241 that communicates between the valve accommodating space 23 and the outside of the housing main body portion 21. The housing opening 241 is closed by attaching the partition wall portion 60 to the housing opening surface 24.

[0123] The pipe member 50 includes a first pipe section 51, a second pipe section 52, and a third pipe section 53, each of which is formed into a cylindrical shape. The first pipe section 51, the second pipe section 52, and the third pipe section 53 are connected by a pipe connecting section 54. The pipe connecting section 54 connects the first pipe section 51, the second pipe section 52, and the third pipe section 53, and is a section for attaching the pipe member 50 to the housing outer wall section 22. The first pipe section 51 has an upstream side disposed inside the first outlet port 261. The second pipe section 52 has an upstream side disposed inside the second outlet port 262. The third pipe section 53 has an upstream side disposed inside the third outlet port 263.

[0124] The partition portion 60 closes the housing opening 241 and holds the valve 90 accommodated in the valve accommodating space 23. The partition portion 60 is disk-shaped with the axial direction DRa being the plate thickness direction, and is arranged so as to be fitted into the housing opening 241 from the other side toward one side in the axial direction DRa. When the partition portion 60 is fitted into the housing opening 241, the outer periphery of the partition portion 60 abuts against the inner circumferential surface of the housing, thereby closing the housing opening 241.

[0125] The drive unit cover 80 houses the drive unit 70. The drive unit cover 80 is made of resin and has a hollow shape, and a drive unit space for housing the drive unit 70 is formed inside. The drive unit cover 80 has a connector section 81 for connecting to the microcomputer 330. The connector section 81 connects the valve device to the microcomputer 330, and has built-in terminals to which the drive unit 70 and the rotation angle sensor 73 are connected.

[0126] The drive unit 70 includes a motor 71 that outputs a rotational force for rotating the valve 90, a gear unit 72 that transmits the output of the motor 71 to the valve 90, and a rotation angle sensor 73 that detects the rotation angle of the gear unit 72. As shown in FIG. 14, the motor 71 includes a motor body, a motor shaft 711, a worm gear 712, and a motor side terminal. The motor 71 is configured so that the motor body can output power when power is supplied to the motor side terminal. The motor body is formed in a substantially cylindrical shape, and the motor shaft 711 protrudes from the other end of the motor body. The power output from the motor body is output to the gear unit 72 via the motor shaft 711 and the worm gear 712.

[0127] The gear portion 72 is composed of a reduction mechanism having a plurality of resin gears, and is configured to be able to transmit the power output from the worm gear 712 to the shaft 92. The gear portion 72 includes a first gear 721, a second gear 722 meshing with the first gear 721, and a third gear 723 meshing with the second gear 722. The shaft 92 is connected to the third gear 723. In the gear portion 72, the outer diameter of the second gear 722 is formed to be larger than the outer diameter of the first gear 721, and the outer diameter of the third gear 723 is formed to be larger than the outer diameter of the second gear 722.

[0128] The first gear 721, the second gear 722, and the third gear 723 are arranged so that their respective axes are perpendicular to the axis of the worm gear 712. The third gear 723 is arranged so that its axis is coaxial with the axis of the shaft 92. The third gear 723 is connected to the shaft 92. The drive unit 70 is configured so that the worm gear 712, the first gear 721, the second gear 722, and the third gear 723 rotate integrally with the valve 90, and the rotations of each are correlated with each other. The rotation angles of these gears and the shaft 92 are correlated with each other, and the rotation angle of any one of the components having the correlation can be calculated from the rotation angle of the other components.

[0129] A rotation angle sensor 73 for detecting the rotation angle of the third gear 723 is attached to the inner periphery of the drive unit cover 80 at a position facing the third gear 723. The rotation angle sensor 73 is a Hall type sensor with a built-in Hall element, and is configured to be able to detect the rotation angle of the third gear 723 in a non-contact manner. The rotation angle sensor 73 is connected to the microcomputer 330 via a connector unit 81. The detected rotation angle of the third gear 723 is transmitted to the microcomputer 330. A processing unit 334 of the microcomputer 330 is configured to be able to calculate the rotation angle of the valve 90 based on the rotation angle of the third gear 723 transmitted from the rotation angle sensor 73.

[0130] The shaft 92 and the valve 90 will be described with reference to Figs. 13 and 15. The shaft 92 is configured to be rotatable about its axis by the rotational force output by the drive unit 70. The valve 90 is connected to the shaft 92, and is configured to be able to rotate the valve 90 integrally with the shaft 92 when the shaft 92 rotates. The shaft 92 is formed to extend in a cylindrical shape along the axis, and penetrates the valve 90 from one side to the other side. One side of the shaft 92 in the axial direction DRa is connected to the shaft support part of the housing main body 21, and the other side is connected to the gear part 72. The valve 90 is fixed to the outer periphery of the shaft.

[0131] The valve 90 is configured to be able to adjust the flow rate of the output fluid by rotating around the axis. The valve 90 has a shaft 92 inserted therein and is accommodated in the valve accommodation space 23 so as to be able to rotate together with the shaft 92. The valve 90 is cylindrical with an axis extending along the axial direction DRa. The valve 90 is formed by connecting a first valve 93, a second valve 94, and a third valve 95, each of which is cylindrical, a cylindrical connection part 914, and a cylindrical valve connection part 915. The valve 90 is arranged such that the first valve 93, the cylindrical connection part 914, the second valve 94, the cylindrical valve connection part 915, and the third valve 95 are arranged in this order from one side to the other side of the axial direction DRa. The first valve 93 and the second valve 94 are connected via the cylindrical connection part 914. The second valve 94 and the third valve 95 are connected via the cylindrical valve connection part 915.

[0132] In the valve accommodating space 23, the second valve 94 and the cylindrical connection portion 914 of the valve 90 face the inlet port 251 in the radial direction DRr. The valve 90 has a cylindrical shaft connection portion 916 in the center into which the shaft 92 is inserted. The valve 90 is connected to the shaft 92 by inserting the shaft 92 into the shaft connection portion 916. In the valve 90, for example, the first valve 93, the second valve 94, the third valve 95, the cylindrical connection portion 914, the cylindrical valve connection portion 915, and the shaft connection portion 916 are integrally molded by injection molding.

[0133] The valve 90 is a valve body for allowing the cooling water that has flowed into the valve 90 to flow out to a first outlet port 261, a second outlet port 262, and a third outlet port 263. When the valve 90 rotates, the first valve 93 opens and closes the first outlet port 261, the second valve 94 opens and closes the second outlet port 262, and the third valve 95 opens and closes the third outlet port 263.

[0134] The first valve 93, the second valve 94, and the third valve 95 are arranged so that their respective axes are coaxial with the axis of the shaft 92. The first valve 93, the second valve 94, and the third valve 95 each have a central portion in the axial direction DRa that bulges outward in the radial direction DRr compared to both end sides. The first valve 93, the second valve 94, and the third valve 95 each are configured to allow fluid to flow inside.

[0135] 15, the first valve 93 has a first valve outer periphery 931 that forms an outer periphery, and a first flow path portion 961 is formed inside the first valve outer periphery 931. The first valve 93 is formed with a first inner opening 936 that allows fluid to flow into the first flow path portion 961. In the first valve 93, the fluid that has flowed into the valve accommodating space 23 flows into the first flow path portion 961 via the first inner opening 936. The first flow path portion 961 corresponds to a flow path portion in a valve device.

[0136] As shown in FIG. 15, the first valve outer periphery 931 is formed with a first outer periphery opening 934 that communicates the first flow passage 961 with the first outlet port 261 via the first seal opening 581 when the shaft 92 rotates. The first valve 93 allows the fluid that has flowed into the first flow passage 961 to flow out from the first outlet port 261 by communicating the first outer periphery opening 934 with the first outlet port 261. The first outer periphery opening 934 formed in the first valve outer periphery 931 corresponds to an outer periphery opening formed in the valve outer periphery. The first outer periphery opening 934 is formed in the first valve outer periphery 931, extending in the circumferential direction of the axis of the shaft 92. The flow rate of the fluid flowing out of the device from the first valve 93 is adjusted according to the area of ​​overlap between the first outer periphery opening 934 and the first seal opening 581 when the shaft 92 rotates. The first inner opening 936 functions as a communication passage that connects the outside of the first valve 93 with the first flow path portion 961 .

[0137] 15, the second valve 94 has a second valve outer periphery 941 forming an outer periphery, and a second flow path portion 962 is formed inside the second valve outer periphery 941. The second valve 94 is formed with a second inner opening 946 that allows the fluid to flow into the second flow path portion 962 on one side in the axial direction DRa. The second valve 94 is configured so that the fluid that flows into the valve accommodating space 23 via the inlet port 251 can flow through the second flow path portion 962 via the second inner opening 946. The second flow path portion 962 corresponds to a flow path portion in a valve device.

[0138] 15, a second outer circumferential opening 944 is formed in the second valve outer circumferential portion 941, which communicates the second flow path portion 962 with the second outlet port 262 via the second seal opening 582 when the shaft 92 rotates. The second valve 94 allows the fluid that has flowed into the second flow path portion 962 to flow out from the second outlet port 262 by communicating the second outer circumferential opening 944 with the second outlet port 262. The second outer circumferential opening 944 formed in the second valve outer circumferential portion 941 corresponds to the outer circumferential opening formed in the valve outer circumferential portion.

[0139] The second outer periphery opening 944 is formed to extend in the circumferential direction of the axis of the shaft 92. The flow rate of the fluid flowing out from the second valve 94 to the outside of the device is adjusted according to the area of ​​overlap between the second outer periphery opening 944 and the second seal opening 582 when the shaft 92 rotates. The second inner opening 946 functions as a communication passage that communicates the outside of the second valve 94 with the second flow path portion 962. The second inner opening 946 faces the first inner opening 936. The cylindrical connection portion 914 is for connecting the first valve 93 and the second valve 94. The cylindrical connection portion 914 forms a first inter-valve space 97 between the outer periphery of the cylindrical connection portion 914 and the inner periphery of the housing. The first flow path portion 961 and the second flow path portion 962 communicate with each other via the first inter-valve space 97.

[0140] The second valve 94 has a shaft connection part 916 disposed in approximately the center inside, the shaft connection part 916 covering the outer periphery of the shaft 92. The second valve 94 has a cylindrical valve connection part 915 connected to the other side in the axial direction DRa of the second valve outer periphery 941. The second valve 94 is configured to allow the fluid that has flowed into the second flow path part 962 to flow into the third valve 95 via the cylindrical valve connection part 915.

[0141] The cylindrical valve connection part 915 has a second inter-valve space 98 formed on the inside. The second inter-valve space 98 is in communication with the second flow path part 962 and the third flow path part 963. The cylindrical valve connection part 915 has an outer diameter on one side in the axial direction DRa that is the same as the outer diameter of the portion of the second valve 94 on the other side in the axial direction DRa. The cylindrical valve connection part 915 has an outer diameter on the other side in the axial direction DRa that is the same as the outer diameter of the portion of the third valve 95 on one side in the axial direction DRa. The cylindrical valve connection part 915 is formed to be continuous with the second valve outer periphery part 941 and the third valve outer periphery part 951.

[0142] 15, the third valve 95 has a third valve outer periphery 951 that forms the outer periphery of the third valve 95, and a third flow path portion 963 is formed inside the third valve outer periphery 951. One side of the third valve outer periphery 951 in the axial direction DRa of the third valve 95 is connected to the cylindrical valve connection portion 915. In the third valve 95, the fluid that has flowed into the second flow path portion 962 flows into the third flow path portion 963 via the second inter-valve space 98. The third flow path portion 963 corresponds to a flow path portion in a valve device.

[0143] 15, a third outer periphery opening 954 is formed in the third valve outer periphery portion 951, which connects the third flow path portion 963 to the third outlet port 263 via the third seal opening 583 when the shaft 92 rotates. The third valve 95 allows the fluid that has flowed into the third flow path portion 963 to flow out of the device from the third outlet port 263 by connecting the third outer periphery opening 954 to the third outlet port 263. The third outer periphery opening 954 formed in the third valve outer periphery portion 951 corresponds to the outer periphery opening formed in the valve outer periphery.

[0144] The third outer periphery opening 954 is formed in the third valve outer periphery 951, extending in the circumferential direction of the axis. The flow rate of the fluid flowing out from the third valve 95 to the outside of the device is adjusted according to the area of ​​overlap between the third outer periphery opening 954 and the third seal opening 583 when the shaft 92 rotates. The shaft connection part 916 is cylindrical, and connects the valve 90 and the shaft 92 by fixing the inserted shaft 92. When the shaft 92 rotates, the shaft connection part 916 transmits the rotational force of the shaft 92 to the valve 90 via the shaft connection part 916. The shaft connection part 916 is formed extending from the second valve 94 to the third valve 95 toward the other side of the axial direction DRa.

[0145] The operation of the water supply valve 152 will be described. The microcomputer 330 calculates the rotation angle of the valve 90 for supplying the necessary flow rate of water to the distribution tube 136, i.e., the rotation angle of the motor 71. The microcomputer 330 transmits information on the calculated rotation angle of the motor 71 to the water supply valve 152. At this time, blocking members are attached to the two fluid outlets that are not connected to the distribution tube 136.

[0146] The water supply valve 152 rotates the motor 71 based on the information on the rotation angle received from the microcomputer 330. By rotating the motor 71, the water supply valve 152 rotates the valve 90 via the gear portion 72 and the shaft 92, and causes a required flow rate of fluid to flow out from the first outer circumferential opening 934, the second outer circumferential opening 944, and the third outer circumferential opening 954.

[0147] For example, a case where the first outlet port 261 is adopted as a fluid outflow portion that communicates with the distribution tube 136 will be described. The water supply valve 152 communicates the first outer periphery opening 934 of the first valve 93 with the first outlet port 261 by rotating the valve 90. The water supply valve 152 adjusts the overlapping area between the first outer periphery opening 934 and the first seal opening 581 by adjusting the rotational position of the valve 90. The water supply valve 152 causes the fluid that has flowed into the valve accommodating space 23 from the inlet port 251 to flow into the first flow path portion 961 via the first inner opening 936, and causes the fluid to flow out from the first outer periphery opening 934 to the first outlet port 261. The microcomputer 330 controls the valve opening, which is the overlapping area between the first outer periphery opening 934 and the first seal opening 581, to control the water jump distance of the irrigation water and supply the irrigation water to a required position.

[0148] For example, a case where the second outlet port 262 is adopted as a fluid outflow portion that communicates with the distribution tube 136 will be described. The water supply valve 152 communicates the second outer periphery opening 944 of the second valve 94 with the second outlet port 262 by rotating the valve 90. The water supply valve 152 adjusts the overlapping area between the second outer periphery opening 944 and the second seal opening 582 by adjusting the rotational position of the valve 90. The water supply valve 152 causes the fluid that has flowed into the valve accommodating space 23 from the inlet port 251 to flow into the second flow passage portion 962 via the second inner opening 946, and causes the fluid to flow out from the second outer periphery opening 944 to the second outlet port 262. The microcomputer 330 controls the valve opening, which is the overlapping area between the second outer periphery opening 944 and the second seal opening 582, to control the water jump distance of the irrigation water and supply the irrigation water to a required position.

[0149] For example, a case where the third outlet port 263 is adopted as a fluid outflow portion that communicates with the distribution tube 136 will be described. The water supply valve 152 communicates the third outer periphery opening 954 of the third valve 95 with the third outlet port 263 by rotating the valve 90. The water supply valve 152 adjusts the overlapping area between the third outer periphery opening 954 and the third seal opening 583 by adjusting the rotational position of the valve 90. The water supply valve 152 causes the fluid that has flowed into the valve accommodating space 23 from the inlet port 251 to flow into the third flow path portion 963 via the second flow path portion 962 of the second valve 94, and causes the fluid to flow out from the third outer periphery opening 954 to the third outlet port 263. The microcomputer 330 controls the valve opening, which is the overlapping area between the third outer periphery opening 954 and the third seal opening 583, to control the water jump distance of the irrigation water and supply the irrigation water to a required position.

[0150] In the water supply valve 152 , the rotation angle sensor 73 detects the rotation angle of the third gear 723 , and feeds back information on the detected rotation angle to the microcomputer 330 , thereby adjusting the rotation angle of the motor 71 .

[0151] The relationship between the rotation angle of the shaft 92 and the flow rate of the valve device will be described with reference to the graph of FIG. 16. In FIG. 16, the horizontal axis represents the rotation angle RA of the motor 71, and the vertical axis represents the flow rate FR of the fluid flowing out of the valve device. In FIG. 16, FO1 is the first valve 93, FO2 is the second valve 94, and FO3 is the third valve 95. In FIG. 16, FS indicates that the valve opening is fully open, FC indicates that the valve opening is fully closed, and MO indicates that the valve opening is intermediate. The intermediate opening is an opening between the fully closed state and the fully open state. The solid line graph in FIG. 16 shows the relationship between the flow rate of the fluid flowing out of the third valve 95 and the rotation angle. The dashed line graph in FIG. 16 shows the relationship between the flow rate of the fluid flowing out of the second valve 94 and the rotation angle. The dashed line graph in FIG. 16 shows the relationship between the flow rate of the fluid flowing out of the first valve 93 and the rotation angle.

[0152] 16, when the rotation angle is near 0 degrees, third valve 95 is fully open and the other valves are fully closed, and fluid flows out of the device only through third valve 95. When the rotation angle is increased from this state, third valve 95 transitions to an intermediate opening, and when the rotation angle is further increased, all three valves are fully closed.

[0153] When the rotation angle of all three valves is increased from a fully closed state, only the second valve 94 transitions to a fully open state via an intermediate opening. When the rotation angle is further increased, the first valve 93 transitions to a fully open state via an intermediate opening, and the first valve 93 and the second valve 94 are in a fully open state. When the rotation angle is increased from this state, the second valve 94 transitions to a fully closed state via an intermediate opening, and the second valve 94 and the third valve 95 are in a fully closed state. When the rotation angle is further increased, the first valve 93 transitions to a fully closed state via an intermediate opening, and all valves are in a fully closed state.

[0154] As described above, the opening degree of each valve changes according to the rotation angle, and the flow rate of fluid flowing out from each valve changes. Each water supply valve 152 in the irrigation system 10 is configured to supply fluid from only one of the three valves, thereby controlling the distance that water splashes into the field 20 and the amount of water supplied according to the rotation angle.

[0155] The effects of the irrigation system 10 of the first embodiment will be described. The irrigation system 10 includes a distribution tube 136 for spraying irrigation water on the field 20, and a water supply valve 152 for controlling the pressure of the irrigation water flowing down the distribution tube 136. The irrigation system 10 includes a control device for controlling the valve opening of the water supply valve 152 to control the flying distance of the irrigation water discharged from the distribution tube 136 through the through-hole.

[0156] According to this irrigation system 10, the valve opening of the water supply valve 152 is controlled to control the irrigation pressure, thereby controlling the flight distance of the irrigation water discharged from the distribution tube 136. Therefore, the irrigation system 10 can perform accurate irrigation by adjusting the flight distance from the distribution tube 136. For example, excessive irrigation near the distribution tube 136 and waste of liquid fertilizer can be suppressed. In addition, since a single distribution tube 136 has a large irrigation range, the number of distribution tubes 136 to be installed in the field 20 can be reduced. The irrigation system 10 can spray water to the necessary places in the soil in accordance with the growth of the plants, and can suppress wasteful irrigation and achieve water saving, thereby suppressing irrigation costs.

[0157] The control device of the irrigation system 10 controls the distance that irrigation water travels from a distribution tube 136 having a plurality of through holes formed therein to a field 20 in which plants 30 are grown. The calculation section of the control device determines the valve opening degree of a water supply valve 152 that controls the pressure of the irrigation water flowing down the distribution tube 136. The output section of the control device outputs a control signal to the water supply valve for controlling the valve opening degree in order to control the distance that irrigation water travels when it is released from the distribution tube 136 via the through holes.

[0158] According to this control device, the calculation unit determines the valve opening, and the output unit outputs a control signal to the water supply valve 152 to control the valve opening in order to control the distance the irrigation water will fly. This makes it possible to control the distance the irrigation water will fly when it is released from the distribution tube 136. This control device can perform accurate irrigation by adjusting the distance the water will fly from the distribution tube 136. This control device can direct water to where it is needed in the soil in accordance with the growth of the plants, and can also reduce unnecessary irrigation, thereby realizing water savings and reducing irrigation costs.

[0159] <Second embodiment> The second embodiment will be described with reference to Fig. 17 to Fig. 19. The irrigation system 10 of the second embodiment executes the control process of the water supply valve 152 according to Fig. 18. The configurations, actions, and effects of the second embodiment that are not specifically described are the same as those of the above-mentioned embodiments, and only the differences will be described below.

[0160] The control process of the water supply valve 152 shown in Fig. 18 is executed in the water supply process shown in Fig. 9 and the irrigation process shown in Fig. 10. The integrated calculation unit 600 and the microcomputer 330 of the monitoring unit 300 that receives the water supply signal output from the integrated calculation unit 600 execute the water supply process shown in Fig. 18. In step S600, the integrated calculation unit 600 outputs the longest irrigation distance to the monitoring unit 300 corresponding to the divided area where irrigation is to be performed.

[0161] The extent to which the roots of the plants 30 in the field 20 spread varies depending on the growth state. Therefore, the maximum root spreading distance, which corresponds to the distance between the distribution tube 136 and the end of the most spread root, varies depending on the growth state. The maximum irrigation distance corresponds to the maximum root spreading distance of the corresponding plant 30. The control device 200 controls the irrigation distance in the water supply process and irrigation process from the vicinity of the distribution tube 136, which includes distance 0, to the maximum irrigation distance.

[0162] The maximum irrigation distance is the distance that irrigation water can fly farthest from the distribution tube 136. The integrated calculation unit 600 estimates the root spreading distance of the plant 30 using an image captured by the camera 318 shown in FIG. 17, and determines the maximum irrigation distance based on the root spreading distance. In the drawing, the camera 318 is written as IS. The integrated calculation unit 600 determines the branch spreading distance of the plant 30 from the image of the plant 30 captured by the camera 318, and estimates the root spreading distance from the branch spreading distance. This estimation utilizes the fact that the branch spreading distance is proportional to the root spreading distance. The integrated calculation unit 600 uses the estimated root spreading distance to determine the maximum irrigation distance, which is the distance that water can fly to the root position farthest from the distribution tube 136. This allows the irrigation system 10 to perform appropriate irrigation at any time according to the growth level of the plant 30.

[0163] The microcomputer 330 corresponding to the divided area to be irrigated determines whether divided irrigation or continuous irrigation is set in step S610. Divided irrigation is a form in which water is irrigated sequentially for each of a plurality of irrigation distances that are different from the distribution tube 136. Continuous irrigation is a form in which the opening of the water supply valve 152 is continuously changed and controlled so that the water splash distance changes smoothly from the vicinity of the distribution tube 136 to the maximum irrigation distance. The setting of divided irrigation or continuous irrigation may be set in advance by the integrated calculation unit 600, for example, or may be set by the user's operation on the input device 800.

[0164] The processing after step S610 is mainly executed by the microcomputer 330 of each monitoring unit 300. If it is determined in step S610 that split irrigation is to be performed, the number of irrigation positions is set in step S620. The irrigation positions are also called split irrigation positions. The number of irrigation positions corresponds to the number of soil sensors 311 provided at positions with different distances from the distribution tube 136 in the vertical direction to the distribution tube 136 within the longest irrigation distance. In step S630, a target irrigation amount, which is a target amount of water to be supplied from the water supply valve 152, is set for each of such irrigation positions. FIG. 19 shows an example in which three irrigation positions are set at a distance closer to the distribution tube 136 in the order of the first irrigation distance D1, the second irrigation distance D2, and the third irrigation distance D3. In step S630, a target irrigation amount, which is a target amount of water to be supplied from the water supply valve 152, is set for each of the first irrigation distance D1, the second irrigation distance D2, and the third irrigation distance D3.

[0165] In step S640, the microcomputer 330 controls the valve opening of the water supply valve 152 so that the water flying distance reaches the irrigation position where irrigation is to be performed among the multiple irrigation positions, and performs irrigation. In step S650, the irrigation flow rate during irrigation is detected using measurements from the water pressure sensor 153 and the soil sensor 311. This irrigation is continued in step S660 until the detected irrigation flow rate reaches the target irrigation amount. If the irrigation flow rate reaches the target irrigation amount in step S660, the microcomputer 330 executes the process of step S670. In step S670, the microcomputer 330 controls the water supply valve 152 to a fully closed state, and ends irrigation at this irrigation position.

[0166] In the next step S680, it is determined whether irrigation has been completed at all irrigation positions set in step S620. If irrigation has not been completed at all irrigation positions, the process returns to step S640. In step S640, the microcomputer 330 controls the valve opening of the water supply valve 152 so that the water jump distance to reach the next irrigation position is achieved, and performs irrigation. Irrigation at the next irrigation position continues until the irrigation flow rate detected in step S660 reaches the target irrigation amount. If it is determined in step S680 that irrigation has been completed at all irrigation positions, the water supply valve 152 is controlled to a fully closed state in step S690 to end irrigation.

[0167] If it is determined in step S610 that continuous irrigation is being performed, the integrated calculation unit 600 outputs in step S720 the shortest irrigation position that is the shortest distance from the distribution tube 136. The processing from step S730 onwards is mainly executed by the microcomputer 330 of each monitoring unit 300. The extent to which the roots of the plant 30 spread varies depending on the growth state. For this reason, the shortest root spreading distance, which corresponds to the distance from the distribution tube 136 to the root located closest to the plant, varies depending on the growth state. The shortest irrigation distance corresponds to the shortest root spreading distance of the corresponding plant 30. The control device 200 controls the irrigation distance in the water supply process and irrigation process from the shortest irrigation distance to the maximum irrigation distance.

[0168] The shortest irrigation distance may be the distance at which the irrigation water can land closest to the distribution tube 136, or the distance at which the irrigation water seeps out from the distribution tube 136 when the distance is zero. The integrated calculation unit 600 estimates the rooting distance of the plant 30 using the image captured by the camera 318, and determines the shortest irrigation distance based on the rooting distance. The integrated calculation unit 600 uses the estimated rooting distance to determine the shortest irrigation distance, which is the distance at which water can be supplied to the root position closest to the distribution tube 136. In step S730, a target irrigation amount is set, which is the target water supply amount to be supplied from the water supply valve 152 over the shortest irrigation distance to the longest irrigation distance. This target irrigation amount is also the average target water supply amount over the shortest irrigation distance to the longest irrigation distance. In the example shown in FIG. 19, the first irrigation distance D1 corresponds to the shortest irrigation distance, and the third irrigation distance D3 corresponds to the longest irrigation distance.

[0169] In step S740, the microcomputer 330 controls the valve opening of the water supply valve 152 so that water is continuously splashed from the shortest irrigation distance to the longest irrigation distance, thereby performing irrigation. In step S740, the microcomputer 330 controls the power supply to the water supply valve 152 by, for example, the lamp operation shown in FIG. 25 or the step operation shown in FIG. 26. By such power supply control, the valve opening of the water supply valve 152 changes finely and continuously. According to the control in step S740, it is possible to provide an even amount of irrigation in which the water splashes and lands on the entire soil in the range from the shortest irrigation distance to the longest irrigation distance. In step S750, the irrigation flow rate during irrigation is detected using the measurements by the water pressure sensor 153 and the soil sensor 311. This irrigation is continued in step S760 until the detected irrigation flow rate reaches the target irrigation amount. When the irrigation flow rate detected in step S760 reaches the target irrigation amount, the microcomputer 330 executes the process of step S770. In step S770, the microcomputer 330 controls the water supply valve 152 to a fully closed state to end the continuous irrigation.

[0170] The effects of the irrigation system 10 of the second embodiment will be described. The control device controls the valve opening of the water supply valve 152 by varying it so that the water jump distance changes continuously between the shortest irrigation position and the longest irrigation position for the distribution tube 136. According to this control, when irrigation is performed, the valve opening is always controlled to change the water jump distance over a wide range between the shortest irrigation position and the longest irrigation position. This continuous watering over a wide range can provide a nearly uniform amount of moisture with little bias to the soil area where the plant needs irrigation.

[0171] The control device controls the valve opening of the water supply valve 152 so as to obtain a water jump distance that reaches the maximum watering distance determined based on the photographed image of the plant 30. This makes it possible to obtain the root spreading range according to the size of the plant detected from the photographed image of the plant, for example, the branch spreading range, and to determine the maximum watering distance with high accuracy. This makes it possible to perform accurate watering to the required range suited to the growth condition of the plant.

[0172] The control device controls the valve opening of the water supply valve 152 to control the water jump distance so as to provide concentrated irrigation to each of the irrigation positions at different distances from the distribution tube 136. This control makes it possible to control the valve opening so as to supply a target amount of irrigation water to each of the irrigation positions when irrigation is performed. This concentrated divided irrigation allows the necessary amount of water to be provided to the entire soil where plants require irrigation by setting appropriate irrigation positions.

[0173] When the target irrigation amount is reached for an irrigation position where intensive irrigation is being performed, the control device controls the valve opening of the water supply valve 152 to change the water jump distance and provide intensive irrigation to the next irrigation position. According to this control, when irrigation is performed, the valve opening is sequentially controlled so that the target irrigation amount is supplied to each of the multiple irrigation positions and this is performed sequentially. This sequential control of the valve opening makes it possible to efficiently provide the necessary amount of moisture to the entire soil where plants require irrigation.

[0174] The multiple soil sensors 311 are capable of detecting soil information, and are provided in the field 20 at positions different distances from the distribution tube 136. The control device measures the water jump distance during irrigation based on the detection information from the multiple soil sensors 311. This makes it possible to simultaneously detect the soil moisture amount and the irrigation position, which contributes to more accurate irrigation.

[0175] <Third embodiment> The third embodiment will be described with reference to Fig. 20. The irrigation system 10 of the third embodiment executes the control process of the water supply valve 152 according to Fig. 20. The configurations, actions, and effects of the third embodiment that are not specifically described are the same as those of the above-mentioned embodiments, and only the differences will be described below. In the flowchart shown in Fig. 18, the flow rate is used as a trigger to change the opening of the water supply valve 152, whereas in the third embodiment, the irrigation time is used as a trigger to change the opening of the water supply valve 152.

[0176] In the flowchart of Fig. 20, the same step references as in Fig. 18 are the same as the processes explained in the second embodiment, and the explanation of those processes will be omitted below. Below, the process steps that are different from the flowchart of the second embodiment will be explained.

[0177] The processes of steps S610 to S690 and steps S730A to S770 are mainly executed by the microcomputer 330 of each monitoring unit 300. In step S630A, the microcomputer 330 sets a target irrigation time, which is a target water supply time for supplying irrigation from the water supply valve 152, for each irrigation position. The target irrigation time is set to a value that satisfies the target amount of irrigation water that can be supplied to the soil at each irrigation position when divided irrigation is performed for each irrigation position set in step S620. The microcomputer 330 continues measuring the irrigation time that started in step S650A until it reaches the target irrigation time in step 660A. When the microcomputer 330 determines that the detected irrigation time has reached the target irrigation time, it executes the subsequent processes in sequence and executes a process to end irrigation in step S690.

[0178] After the integrated calculation unit 600 outputs the shortest irrigation position in step S720, the microcomputer 330 sets a target irrigation time in step S730A. The target irrigation time is set to a value that satisfies the target amount of irrigation water that can be supplied to the soil in the irrigation range when continuous irrigation is performed in the range from the shortest irrigation distance to the longest irrigation distance. The microcomputer 330 continues measuring the irrigation time that started in step S750A until it reaches the target irrigation time in step S760A. When the microcomputer 330 determines that the detected irrigation time has reached the target irrigation time, it executes a process of ending irrigation in step S770.

[0179] The effects of the irrigation system 10 of the third embodiment will be described. When the target irrigation time is reached for an irrigation position where intensive irrigation is being performed, the control device controls the valve opening of the water supply valve 152 to change the water jump distance and provide intensive irrigation to the next irrigation position. According to this control, when irrigation is performed, the valve opening is sequentially controlled so that an amount of water equivalent to the target irrigation time is supplied to each of the multiple irrigation positions and this is performed sequentially. By sequentially controlling the valve opening based on the target irrigation time, the necessary amount of water can be efficiently provided to the entire soil where plants require irrigation.

[0180] <Fourth embodiment> The fourth embodiment will be described with reference to Fig. 21. The irrigation system 10 of the fourth embodiment executes the control process of the water supply valve 152 according to Fig. 21. The configuration, action, and effect of the fourth embodiment that are not specifically described are the same as those of the above-mentioned embodiments, and only the differences will be described below. In the flowchart shown in Fig. 21, a determination is made as to whether or not the irrigation water will reach the target water throw distance according to the wind speed, and a process is carried out to improve the amount of irrigation water so that an appropriate amount is obtained according to the determination result.

[0181] In the flowchart of Fig. 21, the same step symbols as in Fig. 18 are the same as the processes explained in the second embodiment, and the explanation of those processes will be omitted below. In the flowchart of Fig. 21, the process steps different from the flowchart of the second embodiment will be explained. The flowchart of Fig. 21 differs from the flowcharts explained in the second and third embodiments in steps S652 to S656 and S751 to S753.

[0182] The processes of steps S632, S652 to S656, and S751 to S753 are mainly executed by the monitoring unit 300 corresponding to each divided area. In step S632, a permissible value for wind speed is set for each irrigation position. This permissible value is set to a value beyond which it is estimated that irrigation water splashed from the distribution tube 136 will not reach the target irrigation position. This permissible value is stored in, for example, the memory unit 333. After the irrigation flow rate during irrigation is detected in step S650, the current wind speed detected by the wind sensor 317 or the like is obtained in step S652. In step S654, it is determined whether the current wind speed during irrigation is equal to or lower than the permissible value.

[0183] If it is determined in step S654 that the current wind speed is equal to or lower than the allowable value, irrigation has been performed at the target irrigation position, and the process proceeds to step S660 to continue irrigation. If it is determined in step S654 that the current wind speed exceeds the allowable value, it can be estimated that irrigation has not been performed at the target irrigation position. For this reason, in step S656, the water supply valve 152 is controlled to a fully closed state to stop irrigation at the current position. Furthermore, in step S656, the amount of irrigation performed up to that point is calculated and stored in the memory unit 333, and the process proceeds to step S640 to perform irrigation at the next irrigation position. By the above process, if it is estimated that water cannot be splashed to the desired irrigation position due to the current wind speed state, it is possible to prevent unnecessary irrigation. For an irrigation position that was once treated as not being irrigated in this way, irrigation can be performed again in step S640 after it is determined as NO in step S680.

[0184] After detecting the irrigation flow rate during irrigation in step S750, the current wind speed detected by the wind sensor 317 or the like is acquired in step S751. In step S752, it is determined whether the current wind speed during irrigation is equal to or lower than the allowable value, as in step S654. If it is determined in step S752 that the current wind speed is equal to or lower than the allowable value, irrigation has been performed at the target irrigation position in the continuous irrigation, so the process proceeds to step S760 and irrigation is continued. If it is determined in step S752 that the current wind speed exceeds the allowable value, it can be estimated that irrigation has not been performed at the target irrigation position in the continuous irrigation. For this reason, the water supply valve 152 is controlled to a fully closed state in step S753 to stop the continuous irrigation. Furthermore, in step S753, the amount of irrigation performed so far is calculated and stored in the memory unit 333, and the process proceeds to step S753, where irrigation is stopped until the current wind speed becomes equal to or lower than the allowable value.

[0185] If it is determined in step S752 that the current wind speed will be equal to or lower than the allowable value, continuous irrigation is resumed, and in step S760, continuous irrigation is continued until the irrigation amount reaches the target irrigation amount. The irrigation amount determined in step S760 uses the total value of the irrigation amounts stored in memory unit 333 in step S753. As described above, if it can be estimated that a situation has occurred in which water cannot be splashed to the desired irrigation position due to the current wind speed, irrigation is immediately stopped to prevent wasteful continuous irrigation.

[0186] The effects of the irrigation system 10 of the fourth embodiment will be described. When the wind speed in the field 20 exceeds an allowable value, the control device stops controlling the irrigation water throw distance. This control makes it possible to prevent irrigation that does not reach the desired throw distance due to the influence of wind. This makes it possible to prevent unnecessary irrigation, reduce irrigation costs, and provide appropriate irrigation that contributes to the growth of the plants 30.

[0187] The control device stops controlling the irrigation water throw distance when the wind speed in the field 20 exceeds an allowable value. Furthermore, the control device controls the water throw distance by controlling the valve opening of the water supply valve 152 so as to provide concentrated irrigation to the next irrigation position. With this control, when the desired water throw distance cannot be reached due to the effects of wind, irrigation is performed at the next irrigation position, achieving efficient water use. This prevents unnecessary irrigation and reduces irrigation costs, and allows an attempt to retry irrigation when conditions become less susceptible to the effects of wind.

[0188] <Fifth embodiment> The fifth embodiment will be described with reference to Fig. 22 and Fig. 23. The irrigation system 10 of the fifth embodiment executes the control process of the water supply valve 152 according to Fig. 22. The configurations, actions, and effects of the fifth embodiment that are not specifically described are the same as those of the above-mentioned embodiments, and only the differences will be described below. In the flowchart shown in Fig. 22, each monitoring unit 300 executes a process of increasing or decreasing the amount of irrigation water depending on the detection information of the soil sensor 311 to control irrigation.

[0189] The control process of the water supply valve 152 shown in Fig. 22 is executed in the water supply process shown in Fig. 9 and the irrigation process shown in Fig. 10. The microcomputer 330 of the monitoring unit 300 that receives the water supply signal output from the integrated calculation unit 600 mainly executes the water supply process shown in Fig. 22.

[0190] In step S800, the microcomputer 330 corresponding to the divided area where irrigation is to be performed sets the position of the soil sensor 311 installed in the field 20. The soil sensor 311 is installed in advance for each divided area, and its position is stored in the memory unit 333. Next, in step S810, a target sensor value is set for each set soil sensor 311. FIG. 23 shows an example in which the soil sensors 311 are set at three locations that are closer to the distribution tube 136 in the order of the first irrigation distance D1, the second irrigation distance D2, and the third irrigation distance D3. In step S810, a target irrigation amount, which is a target sensor value to be supplied from the water supply valve 152, is set for each of the first irrigation distance D1, the second irrigation distance D2, and the third irrigation distance D3.

[0191] The target sensor value is a value related to a target amount of irrigation water required for an irrigation position corresponding to the position of the soil sensor 311. The soil sensor 311 is a device capable of detecting various types of soil information contained in the soil.

[0192] For example, when the soil sensor 311 detects the current soil moisture content, the irrigation system 10 sets the target irrigation amount necessary for the plant 30 to grow properly as the target sensor value. In this case, irrigation processing is required to replenish the amount of moisture that is insufficient with respect to the target sensor value. Also, when the soil sensor 311 detects the soil temperature, for example, the ease of moisture absorption in the soil can be calculated from the current soil temperature. Based on this data on the ease of moisture absorption, it is possible to determine how much of a target irrigation amount should be supplied to the soil as the target sensor value to reach the amount of water supply necessary for growth.

[0193] When the soil sensor 311 detects a water potential value related to the ease of water absorption by the roots, a target irrigation amount according to the water potential value is set as the target sensor value. When the osmotic pressure of the soil is detected as the water potential value, if the detected osmotic pressure is greater than a set value, water absorption is good. For this reason, the irrigation system 10 sets the target sensor value, which is the target irrigation amount, to be reduced. If the detected osmotic pressure is equal to or less than the set value, water absorption is poor, so the irrigation system 10 sets the target sensor value, which is the target irrigation amount, to be increased more than in the former case.

[0194] When the soil sensor 311 detects electrical conductivity related to the amount of fertilizer in the soil, the target irrigation amount according to the electrical conductivity is set as the target sensor value. If the detected electrical conductivity is greater than the set value, the irrigation system 10 sets the target irrigation amount, which is the target sensor value, to be reduced. If the detected value of the detected electrical conductivity is equal to or less than the set value, the irrigation system 10 sets the target irrigation amount, which is the target sensor value, to be increased more than in the former case.

[0195] In step S820, the microcomputer 330 controls the valve opening of the water supply valve 152 so that the water flying distance reaches the irrigation position where irrigation is to be performed among a plurality of irrigation positions corresponding to the position of the soil sensor 311, thereby performing irrigation. In step S830, the sensor value during irrigation is detected using the measurement value of the soil sensor 311. This irrigation is continued until the detected sensor value reaches a target sensor value in step S840. When the sensor value in step S840 reaches the target sensor value, the microcomputer 330 controls the water supply valve 152 to a fully closed state in step S850, thereby ending irrigation at this irrigation position.

[0196] In the next step S860, it is determined whether or not irrigation has been completed at all irrigation positions set in step S800. If irrigation has not been completed at all irrigation positions, the process returns to step S820. In step S820, the microcomputer 330 controls the opening of the water supply valve 152 so that the water jump distance to reach the next irrigation position is achieved, and performs irrigation. Irrigation at the next irrigation position continues until the sensor value detected in step S840 reaches the target sensor value. If it is determined in step S860 that irrigation has been completed at all irrigation positions, the water supply valve 152 is controlled to a fully closed state in step S870, and irrigation ends.

[0197] <Other embodiments> The disclosure of this specification is not limited to the exemplified embodiments. The disclosure includes the exemplified embodiments and modifications by those skilled in the art based thereon. For example, the disclosure is not limited to the combination of parts and elements shown in the embodiments, and can be implemented in various modifications. The disclosure can be implemented by various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes those in which parts and elements of the embodiments are omitted. The disclosure includes the replacement or combination of parts and elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is indicated by the description of the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the description of the claims.

[0198] The steps S630, S650, and S660 described with reference to FIG. 21 may be replaced with S630A, S650A, and S660A of FIG. 21, respectively. Also, the steps S730, S750, and S760 of FIG. 21 can be replaced with S730A, S750A, and S760A of FIG. 21, respectively. In this case, in steps S656 and S753, the process of storing the irrigation time up to now in the storage unit 333 may be performed.

[0199] An example of the valve opening control of the water supply valve 152 will be described with reference to FIG. 24. FIG. 24 is an example showing the relationship between the valve opening of the water supply valve 152 and the soil moisture content AW during irrigation. In FIG. 24, the horizontal axis represents time, and the vertical axis represents the valve opening and the soil moisture content. The soil moisture content at each position can be detected by the corresponding soil sensor 311. The valve opening is controlled in three steps with the relationship VO1 < VO2 < VO3. FIG. 24 shows the change in the soil moisture content at the irrigation positions of the first irrigation distance D1, the second irrigation distance D2, and the third irrigation distance D3, respectively. The microcomputer 330 energizes the motor 71 at times T1 and T2 in FIG. 24 to control the valve opening of the water supply valve 152 to increase step by step. The energization at time T1 increases the valve opening from VO1 to VO2. The energization at time T2 increases the valve opening from VO2 to VO3. The data related to the valve opening and the irrigation distance as described is stored in the storage unit 333. The processing unit 334 determines the necessary valve opening by performing calculations using the data stored in the storage unit 333. The signal output unit 332 outputs a control signal for controlling the valve opening to the water supply valve 152.

[0200] By this control, until time T1, the water jump distance from the distribution tube 136 corresponds to the first irrigation distance D1, and the amount of water at the first irrigation distance D1 continues to increase. From time T1 to T2, the water jump distance reaches the second irrigation distance D2, the amount of water at the first irrigation distance D1 becomes constant, and the amount of water at the second irrigation distance D2 continues to increase. After time T2, the water jump distance reaches the third irrigation distance D3, the amounts of water at the first irrigation distance D1 and the second irrigation distance D2 become constant, and the amount of water at the third irrigation distance D3 continues to increase. The monitoring unit 300 executes the power supply control related to such valve opening control, triggered by a predetermined time. The monitoring unit 300 measures the water jump distance from the distribution tube 136 based on the detection values ​​of multiple soil sensors 311 installed in advance.

[0201] <Lamp operation power supply> An example of valve opening control of water supply valve 152 will be described with reference to Fig. 25. Fig. 25 is an example showing the relationship between the valve opening of water supply valve 152 and the distance water jumps when irrigation is being performed. Since the valve opening is proportional to the value of the current passed through motor 71, Fig. 25 shows time on the horizontal axis and the current value or the distance water jumps on the vertical axis. The solid line graph in Fig. 25 shows the current value or valve opening indicating lamp operation. Fig. 25 shows the relationship between the valve opening and the distance water jumps during lamp operation. The dashed line graph in Fig. 25 shows the distance water jumps.

[0202] The microcomputer 330 energizes the motor 71 by ramp operation as shown by the solid line in FIG. 25, and controls the valve opening of the water supply valve 152. The microcomputer 330 repeatedly continues energizing the water supply valve 152 with a current waveform whose start and end are zero and whose median is the maximum current value mCV at each of the times 0 to T1, T1 to T2, and T2 to T3. Such a current waveform is also called ramp operation. At this time, the water flying distance for the distribution tube 136 is controlled so that the start and end are zero and the median is the maximum opening mFD. The data on energization by ramp operation and data related to the water flying distance are stored in the memory unit 333. The processing unit 334 determines the valve opening required by ramp operation by calculation using the data stored in the memory unit 333. The signal output unit 332 outputs a control signal to the water supply valve 152 for controlling the valve opening to this value.

[0203] In this way, the output section of the control device outputs a control signal to the water supply valve 152 to execute lamp operation energization in order to control the water throw distance. This energization control allows for irrigation that can supply water evenly over a wide area around the distribution tube 136.

[0204] <Step activation> An example of valve opening control of water supply valve 152 will be described with reference to Fig. 26. Fig. 26 is an example showing the relationship between the valve opening of water supply valve 152 and water jump distance when irrigation is performed. In Fig. 26, the horizontal axis represents time and the vertical axis represents valve opening and water jump distance. The graph shown by the solid line in Fig. 26 shows the valve opening. The graph shown by the dashed line in Fig. 26 shows the water jump distance. Fig. 26 shows the relationship between valve opening and water jump distance due to step operation.

[0205] The microcomputer 330 energizes the motor 71 in a stepwise manner as shown by the solid line in Fig. 26 to control the valve opening of the water supply valve 152. The microcomputer 330 energizes the motor 71 at times T1, T2, and T3 in Fig. 26 to control the valve opening of the water supply valve 152 to be increased in stages. The microcomputer 330 energizes the motor 71 at times T4, T5, and T6 in the opposite direction to that at time T1, etc. to control the valve opening of the water supply valve 152 to be decreased in stages. In the case of the energization control shown in Fig. 26, the valve opening is set to the first opening from times T1 to T2 and from times T5 to T6, and is set to the second opening from times T2 to T3 and from times T4 to T5. The valve opening is set to the third opening, which is the largest opening, from times T3 to T4.

[0206] With this control, the water flying distance from the distribution tube 136 reaches the first irrigation distance D1, for example, between times T1 and T2 and between times T5 and T6. The water flying distance from the distribution tube 136 reaches the second irrigation distance D2, for example, between times T2 and T3 and between times T4 and T5. The water flying distance from the distribution tube 136 reaches the third irrigation distance D3, for example, between times T3 and T4. The monitoring unit 300 executes the power supply control related to this valve opening control, triggered by a predetermined time.

[0207] In this way, the output section of the control device outputs a control signal to execute step action energization to control the distance the water is thrown to the water supply valve 152. This energization control makes it possible to reduce the energization time for controlling the distance the irrigation water is thrown from the distribution tube 136, and thus irrigation can be performed with reduced power consumption.

[0208] An example of the passage configuration and components related to water supply control provided in the irrigation system 10 will be described with reference to FIG. 27. FIG. 27 shows an example showing the positional relationship between the distribution tube 136, the water supply valve 152, and the water pressure sensor 153. The vertical pipe 133 is connected to a plurality of passages leading to the plurality of distribution tubes 136. Each of the plurality of passages connects the distribution tube 136 and the vertical pipe 133. A water supply valve 152 and a water pressure sensor 153a or a flow rate sensor 154a are provided in the passage between each distribution tube 136 and the vertical pipe 133. The water pressure sensor 153a or the flow rate sensor 154a is provided downstream of the water supply valve 152.

[0209] The vertical pipe 133 is connected to a passage leading to the inlet port 251 of each water supply valve 152. Each distribution tube 136 is connected to a passage leading to the first pipe section 51, which is one of the fluid outlet sections of each water supply valve 152. In this case, the second pipe section 52 and the third pipe section 53, which are the other fluid outlet sections, are blocked by a blocking member. In addition, the water pressure sensor 153b or the flow rate sensor 154b may be configured to be provided further downstream than the through hole located at the most downstream position in the distribution tube 136. The distribution tube 136 provided in the irrigation system 10 may be configured to expand and contract depending on the water pressure flowing therethrough. In this case, the distribution tube 136 is formed of a material or hardness that can elastically deform depending on the water pressure, for example.

[0210] The water pressure detected by the water pressure sensor 153a and the water pressure sensor 153b is output to the microcomputer 330 of the monitoring unit 300. The microcomputer 330 feedback-controls the valve opening of each water supply valve 152 to a target opening using the water pressure detected by the water pressure sensor 153a and the water pressure sensor 153b. The microcomputer 330 feedback-controls the valve opening of each water supply valve 152 to a target opening using the flow rate detected by the flow rate sensor 154a and the flow rate sensor 154b. Through this control, the microcomputer 330 can perform irrigation that satisfies the target water discharge amount even if the flow rate and pressure of each distribution tube change due to the elevation difference of the field 20, fluctuations in the water supply source pressure, fluctuations in the amount of irrigation distributed from the vertical pipe 133 to the distribution tube, etc. [Explanation of symbols]

[0211] 20...field, 30...plant, 136...distribution tube, 152...water supply valve, 311...soil sensor, 330...microcomputer (control device), 332...signal output unit (output unit), 334... Processing unit (arithmetic unit)< / rtc>

Claims

1. A distribution tube (136) provided in a field (20) in which a plant (30) is grown and having a plurality of through holes for spraying water to the field; A water supply valve (152) for controlling the pressure of the irrigation water flowing down the distribution tube; A control device (330) for controlling the valve opening of the water supply valve to control the distance of the irrigation water discharged from the distribution tube through the through hole; An irrigation system comprising:

2. The irrigation system according to claim 1 , wherein the control device controls the valve opening of the water supply valve so that the water jump distance changes continuously between the shortest irrigation position and the longest irrigation position for the distribution tube.

3. The irrigation system according to claim 2 , wherein the control device controls the valve opening of the water supply valve so as to obtain the water jump distance that reaches a longest irrigation distance determined based on a photographed image of the plant.

4. The irrigation system of claim 1, wherein the control device controls the valve opening of the water supply valve to control the water jump distance so as to provide concentrated irrigation at each of a plurality of irrigation positions at different distances from the distribution tube.

5. The irrigation system described in claim 4, wherein when the control device reaches a target irrigation amount for the irrigation position where the intensive irrigation is being performed, the control device controls the valve opening of the water supply valve to change the water jump distance and provides intensive irrigation to the next irrigation position.

6. The irrigation system described in claim 4, wherein when the target irrigation time is reached for the irrigation position where the intensive irrigation is being performed, the control device controls the valve opening of the water supply valve to change the water jump distance and provides intensive irrigation to the next irrigation position.

7. The irrigation system according to claim 1 , wherein the control device stops controlling the water throw distance of the irrigation water when a wind speed in the field exceeds a permissible value.

8. An irrigation system as described in any one of claims 4 to 6, wherein the control device stops controlling the water throw distance of the irrigation water when the wind speed in the field exceeds an allowable value, and controls the valve opening of the water supply valve to control the water throw distance so as to provide concentrated irrigation at the next irrigation position.

9. A plurality of soil sensors (311) are provided in the field at positions with different distances from the distribution tube and capable of detecting soil information; The irrigation system according to any one of claims 1 to 8, wherein the control device measures a water jump distance during the irrigation based on detection information from the plurality of soil sensors.

10. a plurality of distribution tubes (136) each having a plurality of through holes for irrigating the field, the distribution tubes being arranged at intervals in the field; The control device, when irrigation water is not being released from the distribution tube, controls the valve opening of a water supply valve (152) that controls the pressure of irrigation water flowing down to an adjacent distribution tube adjacent to the distribution tube from which irrigation water is not being released, thereby controlling the flight distance of the irrigation water released from the adjacent distribution tube so that it reaches the target irrigation position intended for the irrigation water that was not released.

11. A control device for controlling a distance that irrigation water is jetted from a distribution tube (136) having a plurality of through holes formed therein to a field (20) in which plants (30) are grown, comprising: A calculation unit (334) that determines a valve opening degree of a water supply valve (152) that controls the pressure of the irrigation water flowing down to the distribution tube; An output unit (332) that outputs a control signal to the water supply valve to control the valve opening in order to control the distance that the irrigation water is discharged from the distribution tube through the through hole; A control device comprising:

12. The control device according to claim 11 , wherein the output unit outputs a control signal to the water supply valve for executing lamp operation energization in order to control a water throw distance of the irrigation water.

13. The control device according to claim 11 , wherein the output unit outputs a control signal to the water supply valve for executing step action energization to control a water throw distance of the irrigation water.

14. A control device as described in any one of claims 11 to 13, wherein the output section outputs a control signal to the water supply valve to change the valve opening so that the water splash distance changes continuously between the shortest watering position and the longest watering position for the distribution tube.

15. The calculation unit determines the valve opening degree for providing concentrated irrigation to each of a plurality of irrigation positions having different distances from the distribution tube, The control device according to any one of claims 11 to 13, wherein the output section outputs a control signal for controlling the valve opening to the water supply valve.

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