JP7806624B2 - Irrigation Systems and Control Devices - Google Patents

Description

This specification relates to an irrigation system and control device that controls the supply of irrigation water to a field.

Patent Document 1 discloses an irrigation control method that measures the oxygen concentration in the soil and suppresses irrigation when the measured oxygen concentration falls below a predetermined value. Patent Document 2 discloses an irrigation method that supplies water to a field from a water source outside the field and adjusts the soil temperature to a predetermined temperature.

Japanese Patent Application Laid-Open No. 2019-170201 Japanese Patent Application Laid-Open No. 2021-78461

This specification proposes a method of controlling irrigation commands that is not disclosed in the above-mentioned prior art documents in order to eliminate factors that have a negative impact on plants.

The purpose of the disclosure in this specification is to provide an irrigation system and control device that can perform irrigation while minimizing adverse effects on plant growth.

The multiple aspects disclosed in this specification employ different technical means to achieve their respective objectives. Furthermore, the parenthesized symbols in the claims and this section are merely examples that show the correspondence between specific means described in the embodiments described below as one aspect, and do not limit the technical scope.

One of the disclosed irrigation systems includes a water supply path through which irrigation water is supplied to be released to plants, a temperature sensor (160) that detects the temperature of the water supply path, a soil temperature sensor (312) that detects soil temperature, and a control device (200) that controls the amount of irrigation water using the soil temperature detected by the soil temperature sensor and the temperature detected by the temperature sensor , and the control device controls the amount of irrigation water to be reduced when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below an irrigation suppression threshold at the time of irrigation, and controls the amount of irrigation water to be increased when the soil temperature does not exceed the temperature of the water supply path, or when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold, compared to when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below the irrigation suppression threshold .

This irrigation system controls the amount of irrigation water using the temperature of the water supply path, which is related to the temperature of the water supply, and the soil temperature. This allows for control of the amount of irrigation water, varying depending on whether the temperature of the water supply path is high or low relative to the soil temperature. Therefore, when it is predicted that the temperature of the water supply will have a negative impact on plant growth, this irrigation system can provide irrigation that minimizes this.

In one of the disclosed irrigation systems, the control device prohibits irrigation if, at the timing of irrigation, the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below the irrigation suppression threshold, and performs irrigation if the soil temperature does not exceed the temperature of the water supply path, or if the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold.

This irrigation system can suppress irrigation when the temperature of the water supply path is low and has not yet risen to the soil temperature, and can postpone irrigation until the temperature of the water supply path rises. On the other hand, by performing irrigation when the temperature of the water supply path is higher than the soil temperature, or when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold, it is possible to achieve an appropriate supply of moisture that promotes growth while minimizing negative effects on plant growth. Therefore, this irrigation system can perform irrigation while minimizing negative effects on plant growth.

One of the disclosed control devices includes a processing unit (334) that determines whether or not to perform irrigation using the temperature of the water supply path through which irrigation water to be released to plants is supplied and the soil temperature, and a signal output unit (332) that outputs a signal prohibiting irrigation if the processing unit determines that, at the time of performing irrigation, the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below the irrigation suppression threshold , and outputs a signal to perform irrigation if the processing unit determines that the soil temperature does not exceed the temperature of the water supply path or that the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold.
Furthermore, one of the disclosed control devices includes a processing unit (334) that determines whether or not to perform irrigation using the temperature of the water supply path through which irrigation water to be released to plants is supplied and the soil temperature, and a signal output unit (332) that outputs a signal to reduce the amount of irrigation water when the processing unit determines that the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below the irrigation suppression threshold at the time of performing irrigation, and outputs a signal to increase the amount of irrigation water compared to when it is determined that the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below the irrigation suppression threshold if the processing unit determines that the soil temperature does not exceed the temperature of the water supply path or that the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is above the irrigation suppression threshold.

This control device can suppress irrigation when the temperature of the water supply path is low and has not yet risen to the soil temperature, and can postpone irrigation until the temperature of the water supply path rises. On the other hand, by controlling irrigation when the temperature of the water supply path is higher than the soil temperature, or when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold, it is possible to achieve an appropriate supply of moisture that promotes growth while minimizing adverse effects on plants. Therefore, this control device can perform irrigation while minimizing adverse effects on plant growth.

1 is a configuration diagram of an irrigation system according to a first embodiment. FIG. FIG. 2 is a block diagram showing a monitoring unit. FIG. 1 is a cross-sectional view showing a valve device that can be used as a water supply valve. FIG. 2 is a diagram showing the configuration of a drive unit provided in the valve device. FIG. 2 is a perspective view showing a valve provided in the valve device. FIG. 10 is a diagram showing the relationship between the rotation angle and the flow rate in the valve device. FIG. 2 is a water supply route diagram showing the relationship between the water supply valve and various sensors. 10 is a flowchart showing an example of operation when an irrigation command is issued. 10 is a flowchart showing an example of operation when an irrigation command is issued. 10 is a flowchart showing an example of operation when an irrigation command is issued. FIG. 10 is a water supply route diagram showing the relationship between a water supply valve and various sensors in the second embodiment. FIG. 10 is a block diagram showing a monitoring unit according to a second embodiment. 10 is a flowchart showing an operation when an irrigation command is issued in the third embodiment. 10 is a flowchart showing an operation when an irrigation command is issued in the fourth embodiment. 13 is a flowchart showing an operation when an irrigation command is issued in the fifth embodiment. 13 is a flowchart showing an operation when an irrigation command is issued in the sixth embodiment. FIG. 13 is a water supply route diagram showing the relationship between the water supply valve and various sensors in the seventh embodiment. FIG. 13 is a block diagram showing a monitoring unit according to a seventh embodiment. FIG. 13 is a water supply route diagram showing the relationship between the water supply valve and various sensors in the eighth embodiment.

Below, several embodiments for implementing the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment will be assigned the same reference numerals, and duplicate explanations may be omitted. In each embodiment, where only part of the configuration is described, other previously described embodiments may be applied to the remaining parts of the configuration. In addition to combinations of parts that are specifically specified as being possible in each embodiment, it is also possible to partially combine embodiments even if not explicitly specified, as long as there are no particular problems with the combination.

First Embodiment A first embodiment disclosing an example of an irrigation system will be described with reference to Figures 1 to 10. Hereinafter, three mutually orthogonal directions will be 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 "directions" are omitted and simply written as x, y, and z.

<Field>
The irrigation system 10 is applied to an outdoor field 20 cultivated on a hill or plain. As shown in FIG. 1 , the irrigation system 10 is applied to a field 20 cultivated on a plain. The field 20 has an area ranging from several tens of square meters to several thousand square kilometers. The field 20 has multiple growing areas, such as ridges extending in the x direction. These multiple growing areas extending in the x direction are spaced apart in the y direction. Plant seeds or seedlings are planted in each of these multiple growing areas. Examples of such plants include grapes, corn, almonds, raspberries, leafy vegetables, and cotton. The irrigation system 10 may also be configured to be applied to a field 20 located indoors, such as in a greenhouse. Therefore, the field 20 in this specification can be applied to soil located either outdoors or indoors.

Multiple plants are grown in one growing area. The multiple plants are lined up in a row in the x direction. Hereinafter, the multiple plants lined up in a row in the x direction will be referred to as a group of plants. In the field 20, the multiple plant groups are lined up with spacing in the y direction. The shortest distance between the multiple plant groups in the y direction is longer than the shortest distance between the multiple plants in a single group in the x direction. The spacing between the multiple plant groups in the y direction varies depending on the type of plant being grown and the topography and climate of the field 20. The spacing between the multiple plant groups in the y direction is approximately 1 m to 10 m. Even if the branches and leaves of the plants grow thickly in the y direction, there is at least enough width to allow a person to move between two plant groups in the x direction.

<Irrigation system>
The irrigation system 10 comprises a water supply device 100 and a control device 200. The water supply device 100 supplies irrigation water to plants in a field 20. The control device 200 determines the time and amount of irrigation water to be supplied from the water supply device 100 to the plants during the irrigation period. The control device 200 determines the irrigation schedule for the water supply device 100. The irrigation system 10 can detect abnormal conditions such as water leakage and clogging during irrigation, and can restore irrigation (fail-safe) if an abnormal condition occurs.

<Water supply device>
The water supply device 100 includes a pump 110, a water supply pipe 130, etc. The pump 110 is a water supply source that causes irrigation water to flow down the water supply pipe 130.

<Pump>
The pump 110 is always in an operating state. Alternatively, the pump 110 is in a daytime operating state. The control device 200 controls the operation and stopping of the pump 110. The pump 110 pumps irrigation water stored in a tank or 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. The water supply pipe 130 is provided with multiple water supply valves 15 that can control the flow rate of irrigation water discharged into the field 20. When each of these water supply valves 15 is closed and there is no irrigation water leakage 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 referred to as pump pressure) that depends on the discharge capacity of the pump 110. When the water supply valve 15 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 amount of irrigation water discharged becomes stable on average over time, the water pressure in the water supply pipe 130 becomes a flow pressure that is lower than the pump pressure.

<Water supply piping>
The water supply pipe 130 includes a main pipe. The main pipe is connected to a pump 110. The pump 110 supplies irrigation water to the main pipe. The irrigation water is supplied to the field 20 via the main pipe.

<Main piping>
The main pipe includes a vertical pipe 133 and a first connecting pipe 134. The vertical pipe 133 extends in the y direction. The first connecting pipe 134 extends in the x direction. The vertical pipe 133 and the first connecting 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. In the example shown in FIG. 1 , one vertical pipe 133 is connected to one pump 110. Multiple first connecting pipes 134 extend from this vertical pipe 133 extending in the y direction.

The water supply path configurations shown in Figures 1 and 7 are merely examples of irrigation path configurations. There are no particular limitations on the number of pumps 110 and vertical pipes 133 provided in the field 20, the number of vertical pipes 133 connected to one pump 110, the number of vertical pipes 133 connected to one first connecting pipe 134, or the positions of the first connecting pipes 134 and the vertical pipes 133 in the z direction.

The multiple first connecting pipes 134 are arranged at intervals in the y direction. The shortest distance between the multiple first connecting pipes 134 in the y direction is equal to the shortest distance between the multiple plant groups in the y direction. One of the multiple first connecting pipes 134 is provided for one of the multiple plant groups. The first connecting pipe 134 extends in the direction in which the multiple plants included in the plant group are arranged. A supply pipe is connected to this first connecting pipe 134.

The irrigation system 10 has multiple distribution tubes 136 that discharge irrigation water downstream of the first connecting pipe 134 in the water supply path. Each distribution tube 136 is a supply unit that supplies irrigation water to plants in the field 20. Each distribution tube 136 is installed in a position where it can supply irrigation water to ridges created in the field 20. The distribution tubes 136 may be configured with a pressure compensation mechanism that ensures a constant water discharge volume regardless of changes in water pressure, or they may be configured without a pressure compensation mechanism.

The distribution tube 136 has multiple through-holes that connect the inside of the tube through which irrigation water flows with the outside. The multiple through-holes are arranged in a row at a predetermined interval in the axial direction of the tube in each tube. Alternatively, the through-holes may be arranged in a row at a predetermined interval in the circumferential direction of the tube in each tube. The spacing between the multiple through-holes in the axial direction (e.g., the x-direction) is equal to the spacing between the multiple plants in the x-direction. The spacing between the multiple through-holes and the spacing between the multiple plants may also be different.

<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 first connecting pipes 134 connected to the vertical pipe 133. The irrigation water flows in the x direction inside each of the multiple first connecting pipes 134. The irrigation water flowing inside the first connecting pipe 134 flows down into the distribution tube 136 via the branch pipe 134a. The irrigation water is discharged from each through-hole in the distribution tube 136 and supplied to the plants. The irrigation water supplied from each through-hole in the distribution tube 136 is supplied mainly to the trunks and roots of the plants.

The through-holes are, for example, located at a higher position than the part of each distribution tube 136 that faces the ground. In this case, the irrigation water ejected from the through-holes spreads in a radial direction relative to the central axis of the distribution tube 136, allowing it to be sprayed at positions far from the tube.

<Water supply valve>
The water supply valve 15 is provided upstream of the distribution tube 136 in the water supply path. When the water supply valve 15 is in the open state, the water supply pipe 130 and each through-hole of the distribution tube 136 are connected to each other. This allows irrigation water to be discharged from the through-holes. Conversely, when the water supply valve 15 is in the closed state, communication between the water supply pipe 130 and each through-hole of the distribution tube 136 is blocked. This stops irrigation water from being discharged from the through-holes.

The water supply valve 15 controls the flow rate of irrigation water discharged from the through-hole of the distribution tube 136 by controlling the valve opening degree with the control device 200. The control device 200 controls the valve opening degree of the water supply valve 15 to any value between a predetermined opening degree and fully open. The water supply valve 15 is a flow control valve or pressure control valve that can precisely vary the flow rate passing through by adjusting the downstream or upstream pressure. The predetermined opening degree is set to a value that includes a slightly open opening degree or a 0% opening degree, i.e., a fully closed position.

The control device 200 controls the valve opening of the water supply valve 15, thereby controlling the discharge flow rate or discharge flow velocity per unit time discharged from each through-hole. Through this control, the control device 200 can control the water flight distance, which is the distance that irrigation water discharged from the distribution tube 136 lands after leaving the distribution tube 136, or the discharge volume. The water flight distance is the distance between the distribution tube 136 and the point where irrigation water lands on the soil after flying out of the distribution tube 136 through the through-hole. This technology for controlling the water flight distance allows for efficient irrigation of areas that require irrigation, contributing to water conservation. The water supply valve 15 is an on-off valve that controls the flow and cut-off of water supply, and also functions as a flow adjustment valve that can control the water supply flow rate.

The control device 200 determines the irrigation water throw distance based on the type of plant to be irrigated, the extent of the plowed soil layer in the field 20, and other factors. The control device 200 controls the valve opening of the water supply valve 15 so as to obtain the determined water throw distance. For example, the valve opening of the water supply valve 15 is controlled to increase the water throw distance when plants have widespread roots or when the plowed soil layer is shallow and widespread. The valve opening of the water supply valve 15 is also controlled to reduce the water throw distance when plants have deep roots or when the plowed soil layer is located near the distribution tube 136. The water throw distance can be rephrased as the irrigation distance.

<Water pressure sensor>
The water pressure sensor 14 is provided in a pipe included in the water supply pipe 130. The water pressure sensor 14 is a pressure sensor that detects the water pressure inside the pipe. The water pressure detected by the water pressure sensor 14 is output to the control device 200. The water pressure sensor 14 is provided in a position upstream of the distribution tube 136 in the water supply path. Furthermore, the water pressure sensor 14 may be provided in a position downstream of the distribution tube 136 in the water supply path.

When the water supply valve 15 closes and the piping is filled with irrigation water, the water pressure sensor 14 detects the pump pressure. When the water supply valve 15 changes from closed to open, irrigation water is discharged from the distribution tube 136. When the time-averaged amount of irrigation water discharge stabilizes, the water pressure sensor 14 detects the flow pressure. When the water supply valve 15 changes from open to closed, the discharge of irrigation water from the water supply piping 130 stops. The water pressure in the water supply piping 130 gradually recovers from flow pressure to pump pressure. The water pressure sensor 14 detects the water pressure during this transitional period as it gradually recovers from flow pressure to pump pressure.

If a break occurs in the water supply pipe 130 or the water supply valve 15 and irrigation water leaks from the break, the water pressure detected by the water pressure sensor 14 will decrease. This makes it possible to detect whether a break has occurred. This break detection process is performed by the control device 200. The irrigation system 10 may be configured to include a flow sensor that detects the flow rate of fluid flowing through the passageway instead of the water pressure sensor 14. The irrigation system 10 uses the detection values of the water pressure sensor 14 and the flow sensor to feedback control the valve opening of the water supply valve 15.

<Control device>
1 and 2 , 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 represented as ICD. The control device 200 has multiple monitoring units 300. Each of the multiple monitoring units 300 corresponds to a predetermined divided area in the farm field 20.

The monitoring unit 300 receives the water pressure detected by the water pressure sensor 14. The monitoring unit 300 detects environmental values, which are physical quantities related to the environment of the farm field 20. Each of the multiple monitoring units 300 outputs the water pressure and environmental values to the integrated communication unit 400 via wireless communication.

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 these water pressures and environmental values. An example of an information storage unit 500 is a so-called cloud. The integrated calculation unit 600 reads out various information such as water pressure and environmental values stored in the information storage unit 500. The integrated calculation unit 600 processes the read out information as appropriate and displays the information and processing results on the monitor 700 of the user's smartphone or computer.

The integrated calculation unit 600 is included in a user's smartphone, personal computer, etc. 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 calculations related to irrigation processing. This function is realized by downloading an irrigation application program to the information processing calculation device 610. The integrated calculation unit 600 may be a calculation device implemented on the cloud. In this case, the integrated calculation unit 600 and the information storage unit 500 may be implemented together on the cloud.

Memory 620 is a non-transient, tangible storage medium that non-temporarily stores various programs and information that can be read by a computer or processor. Memory 620 has volatile memory and non-volatile memory. Memory 620 stores various information input to communication device 630 and the processing results of information processing device 610. Information processing device 610 performs various arithmetic operations using the information stored in memory 620.

The communication device 630 has wireless communication capabilities. The communication device 630 converts received wireless signals into electrical signals and outputs them to the information processing computing device 610. The communication device 630 outputs the processing results of the information processing computing device 610 as wireless signals. Hereinafter, the technical content of this embodiment will be explained using the general term integrated computing unit 600 without distinguishing between the information processing computing device 610, memory 620, and communication device 630. The information processing computing device 610 corresponds to the processing computing unit.

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

When the integrated calculation unit 600 detects an irrigation processing command or determines that it is time to start supplying irrigation water based on the irrigation schedule, it outputs an instruction signal to the information storage unit 500 to control the water supply valve 15. 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 the output or non-output of a water supply signal to the water supply valve 15 based on the instruction signal. This controls the open/close state of the water supply valve 15. 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.

<Divided area>
One monitoring unit 300 is provided for each distribution tube 136. A configuration in which one monitoring unit 300 is provided for a predetermined number of distribution tubes 136 may also be adopted. A monitoring unit 300 may also be provided for each ridge. As shown in FIG. 1 , the multiple monitoring units 300, together with the water supply valves 15 and water pressure sensors 14, 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.

With this configuration, the environment for each of the multiple divided areas separated by rows and columns is monitored individually by the monitoring unit 300 corresponding to each divided area. Furthermore, the supply of irrigation water to each divided area is controlled individually by the corresponding monitoring unit 300.

<Monitoring Department>
As shown in Figure 2, the monitoring unit 300 includes a control unit 320. The environmental sensor 310, water supply valve 15, water pressure sensor 14, water temperature sensor 160, and other components are electrically connected to the control unit 320. In the drawing, the environmental sensor 310 is represented as ES, the water supply valve 15 as WV, and the water pressure sensor 14 as WPS. The water supply valve 15 is specifically represented by water supply valve 150 and water supply valve 151 as devices provided in the water supply path. The water pressure sensor 14 is specifically represented by water pressure sensor 140, water pressure sensor 141, and water pressure sensor 142 as devices provided in the water supply path.

Multiple environmental sensors 310 are arranged in a matrix in the field 20, corresponding to multiple divided areas. Each environmental sensor 310 detects the environmental values of each divided area. The water pressure sensor 14 detects the water pressure of each divided area. The detected environmental values and water pressure of each divided area are stored in the information storage unit 500.

The control unit 320 includes a microcomputer 330, a communication unit 340, an RTC 350, and a power generation unit 360. "Microcomputer" stands for "microcomputer." "RTC" stands for "real time clock." In the drawings, the communication unit 340 is referred to as "CDP."

Environmental values and water pressure are input to the microcomputer 330. The microcomputer 330 outputs these environmental values and water pressure to the integrated communication unit 400 via the communication unit 340. An instruction signal is input to the microcomputer 330 from the integrated communication unit 400. The microcomputer 330 outputs a water supply signal to the water supply valve 15 based on this instruction signal. The microcomputer 330 corresponds to the calculation processing unit. The microcomputer 330 is a control device that controls the operation of the water supply valve 15. The microcomputer 330 has a sleep mode and a normal mode as its operating modes. In sleep mode, the microcomputer 330 stops calculation processing. In normal mode, the microcomputer 330 is executing calculation processing. Normal mode consumes more power than sleep mode.

The communication unit 340 communicates wirelessly 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 contains an instruction signal, the microcomputer 330 switches from sleep mode to normal mode. The microcomputer 330 may be configured to wake up before receiving the electrical signal.

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, RTC 350 outputs a wake-up signal to microcontroller 330. When this wake-up signal is input to microcontroller 330 in sleep mode, microcontroller 330 switches from sleep mode to normal mode.

The power generation unit 360 converts light energy acquired by the solar cell 361 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 and timer functions of the RTC 350 from being impaired. The solar cell 361 may be replaced with a primary or secondary battery.

<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 for 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.

One of the environmental values that is expected to differ for each divided area depending on the topography of the field 20 and the plant growth conditions is the amount of solar radiation. In this specification, each environmental sensor 310 is equipped with a solar radiation sensor that detects the amount of solar radiation. The multiple solar radiation sensors detect the amount of solar radiation in multiple divided areas of the field 20.

The monitor 700 displays a map of the soil moisture distribution and solar radiation distribution in the field 20 by arranging the soil moisture amounts and solar radiation amounts detected in multiple divided areas in a matrix. Similarly, the monitor 700 displays a map of the water pressure distribution in the water supply pipes 130 in the field 20 by arranging the water pressures detected by multiple water pressure sensors 14 in a matrix. This map display processing is performed by the integrated calculation unit 600.

Environmental values in the field 20 include rainfall, temperature, humidity, air pressure, carbon dioxide concentration, and wind volume. Sensors that detect these environmental values include a rain sensor, a soil temperature sensor 312, a humidity sensor, an air pressure sensor, a CO2 sensor, and a wind sensor. These are included in at least one environmental sensor 310 of the multiple monitoring units 300.

The environmental sensor 310 of the monitoring unit 300 includes various sensors that detect these environmental values for the entire field 20. In the drawings, the soil temperature sensor 312 is abbreviated as GTS. The wind sensor may be configured to detect not only wind volume but also wind direction. A configuration may also be adopted in which at least one of the rain sensor, soil temperature sensor 312, humidity sensor, air pressure sensor, and wind sensor is arranged in a matrix in the field 20.

This configuration is effective when, for example, the field 20 is large, has significant undulations, or experiences drastic climate changes, resulting in large fluctuations in the amount of rainfall, temperature, humidity, air pressure, and wind volume for each divided area. By arranging the amount of rainfall, temperature, humidity, air pressure, and wind volume detected by these sensors in a matrix, these environmental values can be displayed 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.

<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, thereby individually controlling the soil moisture content for each divided area.

Plants have roots in the plowed soil layer of the field 20. Plant growth depends on the amount of water contained in the soil in this plowed soil layer (also known as soil moisture content). If the soil moisture content exceeds the growth-inhibiting moisture point, the plant will develop disease. If the soil moisture content falls below the permanent wilting point, the plant will wilt and will not recover. The growth-inhibiting moisture point and permanent wilting point differ depending on the type of plant, and these values are stored in the information storage unit 500.

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

The soil moisture content in the plowed soil layer increases or decreases depending on 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. The soil moisture content also decreases when plants absorb the water or when water seeps into layers below the plowed soil layer. The amount of rain that falls on the plowed soil layer (rainfall) is detected by a rain sensor. The evaporation rate, which is the amount of water that evaporates from the plowed soil layer, depends on the amount of solar radiation, temperature, humidity, and wind volume. These are detected by a solar radiation sensor, soil temperature sensor 312, humidity sensor, and wind sensor.

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

As described above, the environmental sensor 310 detects the current soil moisture content in the plowed soil layer, as well as predicted values for increases and decreases in soil moisture content from the current value due to environmental changes. These are stored as environmental values in the information storage unit 500. The information storage unit 500 stores the plant growth inhibition moisture point and permanent wilting point, the amount of water absorbed by the plant per unit time, and the soil's moisture retention capacity. The user instructions described above are stored in the information storage unit 500. In this way, the information storage unit 500 stores various information for determining the irrigation schedule. The irrigation system 10 may be configured to check the detection value of the soil sensor in real time and stop irrigation when the detection value reaches a threshold value.

<Microcomputer>
2, the microcomputer 330 includes an acquisition unit 331, a signal output unit 332, a memory 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 memory unit 333 as MU, and the processing unit 334 as PU. The acquisition unit 331 receives as input an environmental value detected by the environmental sensor 310. The acquisition unit 331 receives as input a water pressure detected by the water pressure sensor 14. The acquisition unit 331 is electrically connected to the environmental sensor 310 and the water pressure sensor 14.

The signal output unit 332 is electrically connected to the water supply valve 15. A control signal (water supply signal) for controlling the valve opening of the water supply valve 15 is output from the signal output unit 332 to the water supply valve 15. When no water supply signal is input, the water supply valve 15 is closed. When a water supply signal is input, the water supply valve 15 is open. The water supply valve 15 may also be configured to maintain its current state when no water supply signal is input, and to open or close in accordance with the input content when a water supply signal is input. For example, when no control signal is input, the valve opening of the water supply valve 15 is maintained, and the valve opening of the water supply valve 15 is adjusted in accordance with the control signal indicating the opening amount input when an input signal is input.

The memory unit 333 is a non-transient tangible storage medium that non-temporarily stores programs and data that can be read by a computer or processor. The memory unit 333 has volatile memory and non-volatile memory. The memory unit 333 stores a program that the processing unit 334 uses to execute calculations. This program includes at least a portion of the irrigation application program described above. The memory unit 333 temporarily stores data used when the processing unit 334 executes calculations. The memory unit 333 stores various data input to the acquisition unit 331 and communication unit 340, as well as the acquisition times of the various data.

When a wake-up signal is input from the RTC 350, the processing unit 334 switches from sleep mode to normal mode. In normal mode, the processing unit 334 reads the programs and various data stored in the memory unit 333 and executes calculations. This calculation includes calculating the valve opening required to allow water splashed through the through-holes of the distribution tube 136 to reach the desired irrigation position. The processing unit 334 corresponds to a calculation unit. This calculation may be performed by the information processing calculation device 610 of the integrated calculation unit 600.

The processing unit 334 reads from the RTC 350 the acquisition times of various sensor signals input to the acquisition unit 331 and instruction signals input to the communication unit 340. The processing unit 334 stores the instruction signals and acquisition times in the memory unit 333. The acquisition times may be read by having the integrated communication unit 400 record the data acquisition time when it receives data wirelessly from each monitoring unit 300. Alternatively, the information storage unit 500 may record the data acquisition time when it receives data wirelessly from the integrated communication unit 400.

The processing unit 334 stores the environmental values and water pressure input from the environmental sensor 310 and water pressure sensor 14, as well as the time of their acquisition, in the information storage unit 500 via the communication unit 340 and integrated communication unit 400. The processing unit 334 outputs a water supply signal to the water supply valve 15 via the signal output unit 332 based on an instruction signal input from the integrated calculation unit 600 via the information storage unit 500, integrated communication unit 400, and communication unit 340.

<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 this 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 this electrical signal to the processing unit 334. The wireless signal output by the communication unit 340 includes an address and data. Wireless signals are transmitted and received between the multiple communication units 340 and the integrated communication unit 400. The address 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 is stored in each of the multiple memory units 333.

The wireless signal output from the integrated communication unit 400 also contains an address. The data in this wireless signal contains an instruction signal. This wireless signal is received by each communication unit 340. This wireless signal is converted into an electrical signal by each communication unit 340. This electrical signal is then input to each processing unit 334. Of the multiple processing units 334, only the processing unit 334 that has the same address as the address contained in the electrical signal executes arithmetic processing based on that electrical signal. The microcomputer 330 operates intermittently, alternating between sleep mode and normal mode. For this reason, wireless communication between the communication unit 340 and the integrated communication unit 400 is not performed frequently.

<Power Generation Division>
The power generation unit 360 includes a solar cell 361, a power storage unit 362, a voltage 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 voltage 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 this electrical energy (power). The power stored in the power storage unit 362 is used to drive the monitoring unit 300.

The voltage sensor 363 detects the voltage value output from the solar cell 361 to the power storage unit 362. The power sensor 364 detects the power output from the power storage unit 362. The processing unit 334 stores the detected current and power values in the information storage unit 500 via the communication unit 340 and the integrated communication unit 400. The driving power of the monitoring unit 300 depends on the power generated by the power generation unit 360. Therefore, if the amount of light incident on the power generation unit 360 is low, the driving power of the monitoring unit 300 may be insufficient. To avoid this, the microcomputer 330 of the monitoring unit 300 operates intermittently. The voltage sensor 363 may be replaced with a current sensor that detects the current output from the solar cell 361 to the power storage unit 362. The power generation unit 360 may also be configured without a voltage sensor or current sensor.

<RTC>
The RTC 350 outputs a wake-up signal to the microcomputer 330 every time the above-described 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 in accordance with the amount of power stored in the power storage unit 362 (amount of stored power). The intermittent drive interval is determined by the integrated calculation unit 600 in accordance with the amount of stored power.

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 receives 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.

<Driving the irrigation system>
In the irrigation system 10, signals are sent 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 cycle and an event task that is processed suddenly.

These cycle tasks and event tasks have a processing priority. If the processing timing of these tasks is the same, the event task takes priority over the cycle task. As cycle tasks, each monitoring unit 300 performs sensor processing. The integrated calculation unit 600 performs update processing. As event tasks, each monitoring unit 300 performs monitoring processing and water supply processing. The integrated calculation unit 600 performs irrigation processing, user update processing, and forced update processing.

<Sensor processing>
Before sensor processing, the microcomputer 330 of the monitoring unit 300 is in sleep mode, and a wake-up signal is input to this microcomputer 330 from the RTC 350. This switches the microcomputer 330 from sleep mode to normal mode. The microcomputer 330 then begins executing sensor processing. The sensor processing is executed at the microcomputer 330's intermittent drive interval. First, the microcomputer 330 acquires sensor signals input from various sensors, and then acquires the acquisition times of the sensor signals based on the output of the RTC 350. The microcomputer 330 then stores the acquired sensor signals and their acquisition times. Next, the communication unit 340 outputs the sensor signals and their acquisition times as sensor information to the integrated communication unit 400 via wireless communication. The integrated communication unit 400 stores this sensor information in the information storage unit 500. The microcomputer 330 then transitions to sleep mode and ends sensor processing.

<Update process>
The integrated calculation unit 600 executes the update process every update period. This update period is approximately the same as the intermittent drive interval of the microcomputer 330. First, it reads out the various pieces of information stored in the information storage unit 500. Next, it updates the irrigation schedules of each of the multiple monitoring units 300 based on the read-in information. 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 at which sensor processing is executed. The integrated calculation unit 600 retains the updated irrigation schedule and intermittent drive interval itself, and stores them in the information storage unit 500, thereby completing the update process. As described above, the sensor information, irrigation schedule, and intermittent drive interval are updated by the cycle task.

The monitoring process, water supply process, and irrigation process are each performed during the daytime to avoid depleting the driving power of the monitoring unit 300. Whether it is daytime or not can be determined based on the current time and the amount of solar radiation detected by the solar radiation sensor, etc.

<Monitoring process>
Before the monitoring process, 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 sleep mode to normal mode and starts executing the monitoring process.

First, the input instruction signal and the time it was acquired are stored. Next, it is determined whether the instruction signal includes a water supply instruction to change the water supply valve 15 from a closed state to an open state. If the instruction signal includes a water supply instruction, the water supply process is executed. In the water supply process, the microcomputer 330 outputs a water supply signal to the water supply valve 15 in accordance with the water supply instruction. Furthermore, the microcomputer 330 determines whether the water supply time included in the instruction signal has elapsed. If the water supply time has not elapsed, it continues to output the water supply signal to the water supply valve 15. If the water supply time has elapsed, it stops outputting the water supply signal and ends the water supply process.

If the instruction signal does not contain a water supply instruction, the water supply process is not performed, and it is determined whether the instruction signal contains an instruction to update the intermittent drive interval. The 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 on a regular or irregular basis. If the instruction signal contains an instruction to update the intermittent drive interval, the processing unit 334 of the microcomputer 330 adjusts the time interval at which the RTC 350 outputs a wake-up signal.

If the instruction signal does not include an instruction to update the intermittent drive interval, sensor processing is performed. If water supply processing is performed, the sensor processing detects the environmental value after irrigation is supplied. If water supply processing is not performed, the sensor processing detects the environmental value when irrigation is not being supplied. This environmental value is stored in the information storage unit 500. Once sensor processing is complete, the microcomputer 330 transitions to sleep mode and ends the monitoring processing. The condition for starting the monitoring processing is not limited to an instruction signal from the integrated calculation unit 600. After the RTC 350 starts the microcomputer 330, the microcomputer 330 processes the sensor data and then sends it to the integrated calculation unit 600. The integrated calculation unit 600 may then send an instruction for the timing of the next intermittent drive along with an instruction for the valve opening.

<Irrigation treatment>
The integrated calculation unit 600 executes the irrigation process whenever it is time to supply irrigation water according to the irrigation schedule of each monitoring unit 300. The integrated calculation unit 600 first outputs a water supply signal including a water supply instruction to the monitoring unit 300 of the multiple monitoring units 300 that corresponds to the divided area to which irrigation water is to be supplied. 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 above.

The integrated calculation unit 600 remains in a standby state until the monitoring unit 300 has completed its monitoring process. When the monitoring process has completed, it executes the update process. Whether the monitoring process has completed is determined, for example, based on whether the time required for the monitoring process to complete has elapsed. Whether the monitoring process has completed can be determined by querying the monitoring unit 300. There are no particular limitations on the method for determining whether the monitoring process has completed.

<User update process>
The integrated calculation unit 600 executes the user update process when a user instruction related to adjusting the watering schedule or the intermittent drive interval is input from the input device 800. The integrated calculation unit 600 first stores the input user instruction in the information storage unit 500. Next, it executes the update process described above. As a result, the watering schedule and the intermittent drive interval are updated based on the user instruction.

<Forced update process>
The integrated calculation unit 600 executes the forced update process when a user instruction related to updating the watering schedule and the intermittent drive interval is input. The integrated calculation unit 600 first outputs a request signal including a request instruction requesting the execution of sensor processing. This request signal is output to the monitoring unit 300 via wireless communication. Next, the update process enters a standby state until the sensor processing by the monitoring unit 300 is completed.

When sensor processing is complete, the update process described above is executed. Whether sensor processing is complete can be determined, for example, based on whether the time expected for sensor processing to complete has passed. Alternatively, whether sensor processing is complete can be determined by querying the monitoring unit 300. There are no particular limitations on the method for determining whether sensor processing is complete. The watering schedule and intermittent drive interval are updated based on various data at the time of the user's update request.

<Individual irrigation treatment>
As described above, the integrated calculation unit 600 determines the irrigation 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 divided area 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.

<Independent update>
As another 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 above-mentioned update process.

<Weather forecast and irrigation schedule>
The information storage unit 500 stores the current soil moisture content, predicted declines, and user instructions. The information storage unit 500 also stores the plant growth inhibition moisture point and permanent wilting point, the amount of water absorbed by the plant per unit time, and the soil's moisture retention capacity. In addition, the information storage unit 500 stores a weather forecast for the field 20 output from an external information source 1000. In FIG. 1, the external information source 1000 is abbreviated as ESI. The integrated calculation unit 600 reads various information, including the weather forecast, from the information storage unit 500 during the update process. The integrated calculation unit 600 determines the irrigation schedule for each monitoring unit 300.

<Target and estimated values>
The integrated calculation unit 600 calculates a target value and an estimated value of soil moisture content when determining the irrigation schedule. The target value of soil moisture content is naturally set to a value between the growth inhibition moisture point and the permanent wilting point. In order to attempt to grow plants healthily, the target value of soil moisture content is set to a value that is somewhat away from each of the theoretical values of the growth inhibition moisture point and the permanent wilting point.

The integrated calculation unit 600 sets the target values for this soil moisture content as an upper target value on the growth inhibition moisture point side and a lower target value on the permanent wilting point side. The integrated calculation unit 600 determines the irrigation schedule so that the estimated soil moisture content falls between the upper target value and the lower target value during the irrigation period of the irrigation schedule. Even if rainfall is predicted to cause the estimated soil moisture content to exceed the upper target value, the integrated calculation unit 600 determines the irrigation schedule so that the estimated soil moisture content does not exceed the growth inhibition moisture point.

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, as well as taking into account the healthy growth of the plants mentioned above. The climate of the field 20 includes the expected average rainfall for the field 20 during the irrigation period in the irrigation schedule, and the total rainfall predicted by the weather forecast for the irrigation period. The expected average rainfall for the field 20 during the irrigation period is stored in the information storage unit 500.

There is a deviation between the permanent wilting point and the lower limit target value. This lower limit deviation range is determined based on factors such as the healthy growth of the plant, the expected recovery time when a failure occurs in the water supply device 100, and the decrease in soil moisture content per unit time. For example, the lower limit deviation range 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.

For example, if 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 a watering schedule for that week. If the weather forecast does not predict any rainfall during that week, the estimated soil moisture content is expected to gradually decrease over time. The decrease in this estimated soil moisture content per unit time is determined based on the predicted decrease in soil moisture content in the plow layer. For ease of notation, the estimated soil moisture content will be referred to simply as the estimated value where necessary.

As described above, the irrigation schedule is determined based on estimated soil moisture content based on environmental values, etc., and weather forecasts. This prevents the soil moisture content in outdoor divided areas from becoming unsuitable for plants due to weather changes such as rainfall or dryness.

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 prevents 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 prevents the soil moisture content from increasing excessively even if the amount of rainfall is greater than the forecast. The irrigation system 10 may also check the detection value of the soil sensor 311 in real time and stop irrigation when the detection value reaches a threshold value. In this case, there is no need to calculate the estimated soil moisture content.

An example of a valve device applicable to the water supply valve 15 will be described below with reference to Figures 3 to 5. This valve device is a so-called rotary valve device. This valve device has one fluid inlet and three fluid outlets. This valve device is installed in the irrigation system 10 by connecting an upstream pipe to the fluid inlet and connecting a distribution tube 136 to one of the fluid outlets. Furthermore, a blocking member can be attached to the fluid outlet not connected to the distribution tube 136 to block the passage.

As shown in Figure 3, 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 around the axis of the 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.

The housing 9 is an accommodating portion 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 allows cooling water to flow out of the housing main body 21, and a partition wall 60 that is attached to the housing main body 21. The housing main body 21 has a generally rectangular parallelepiped appearance and is formed with a bottom and an opening on the other side in the axial direction DRa. The housing main body 21 has a housing outer wall 22 that forms the outer periphery of the housing main body 21. The housing outer wall 22 forms a cylindrical valve accommodating space 23 within the housing main body 21, with its axis aligned in the axial direction DRa.

An inlet port 251 is formed in the housing outer wall portion 22 to allow supply water to flow into the valve accommodating space 23. The inlet port 251 has a circular opening and is connected to the connecting pipe 135. The inlet port 251 corresponds to the fluid inlet portion.

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 fluid outlet ports.

A partition wall 60 is attached to the housing opening surface 24 in the housing outer wall portion 22. The housing opening surface 24 is located on the other side of the housing main body portion 21 in the axial direction DRa. A housing opening 241 is formed in the housing opening surface 24, connecting the valve accommodating space 23 with the outside of the housing main body portion 21. The housing opening 241 is closed by attaching the partition wall 60 to the housing opening surface 24.

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 cylindrical. The first pipe section 51, the second pipe section 52, and the third pipe section 53 are connected by a pipe connector 54. The pipe connector 54 connects the first pipe section 51, the second pipe section 52, and the third pipe section 53, and is used to attach the pipe member 50 to the housing outer wall section 22. The upstream side of the first pipe section 51 is located inside the first outlet port 261. The upstream side of the second pipe section 52 is located inside the second outlet port 262. The upstream side of the third pipe section 53 is located inside the third outlet port 263.

The partition wall portion 60 closes the housing opening 241 and holds the valve 90 housed in the valve accommodating space 23. The partition wall portion 60 is disk-shaped with the axial direction DRa being the plate thickness direction, and is positioned so that it fits into the housing opening 241 from one side to the other side in the axial direction DRa. When the partition wall portion 60 is fitted into the housing opening 241, the outer periphery of the partition wall portion 60 abuts against the inner circumferential surface of the housing, thereby closing the housing opening 241.

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

The drive unit 70 includes a motor 71 that outputs a rotational force to rotate 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. 4, 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 roughly 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 worm gear 712.

The gear section 72 is composed of a reduction mechanism having multiple resin gears, and is configured to transmit the power output from the worm gear 712 to the shaft 92. The gear section 72 includes a first gear 721, a second gear 722 that meshes with the first gear 721, and a third gear 723 that meshes with the second gear 722. The shaft 92 is connected to the third gear 723. The gear section 72 is configured such that the outer diameter of the second gear 722 is larger than the outer diameter of the first gear 721, and the outer diameter of the third gear 723 is larger than the outer diameter of the second gear 722.

The first gear 721, second gear 722, and 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, first gear 721, second gear 722, and third gear 723 rotate integrally with the valve 90, and their respective rotations are correlated with each other. The rotation angles of these gears and the shaft 92 are correlated, and the rotation angle of any one of the correlated components can be calculated from the rotation angle of the other components.

A rotation angle sensor 73 that detects the rotation angle of the third gear 723 is attached to the inner periphery of the drive unit cover 80, at a location facing the third gear 723. The rotation angle sensor 73 is a Hall sensor with a built-in Hall element, and is configured to detect the rotation angle of the third gear 723 without contact. The rotation angle sensor 73 is connected to the microcomputer 330 via the connector 81. The detected rotation angle of the third gear 723 is transmitted to the microcomputer 330. The processing unit 334 of the microcomputer 330 is configured 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.

The shaft 92 and valve 90 will be described with reference to Figures 3 and 5. 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 so that when the shaft 92 rotates, the valve 90 can rotate integrally with the shaft 92. The shaft 92 is formed to extend cylindrically along the axis, penetrating from one side of the valve 90 to the other. One side of the shaft 92 in the axial direction DRa is connected to the shaft support portion of the housing main body 21, and the other side is connected to the gear portion 72. The valve 90 is fixed to the outer periphery of the shaft.

The valve 90 is configured to be able to adjust the flow rate of the output fluid by rotating around its axis. A shaft 92 is inserted into the valve 90, and the valve 90 is housed in the valve housing space 23 so that it can rotate integrally 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 connecting portion 914, and a cylindrical valve connecting portion 915. The valve 90 is arranged with the first valve 93, the cylindrical connecting portion 914, the second valve 94, the cylindrical valve connecting portion 915, and the third valve 95, arranged in this order from one side to the other in the axial direction DRa. The first valve 93 and the second valve 94 are connected via the cylindrical connecting portion 914. The second valve 94 and the third valve 95 are connected via the cylindrical valve connecting portion 915.

In the valve accommodating space 23, the second valve 94 and the cylindrical connecting portion 914 of the valve 90 face the inlet port 251 in the radial direction DRr. The valve 90 has a cylindrical shaft connecting 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 connecting portion 916. In the valve 90, for example, the first valve 93, second valve 94, third valve 95, cylindrical connecting portion 914, cylindrical valve connecting portion 915, and shaft connecting portion 916 are integrally molded by injection molding.

Valve 90 is a valve body that allows the cooling water that flows into the valve 90 to flow out to the first outlet port 261, the second outlet port 262, and the 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.

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

As shown in FIG. 5, the first valve 93 has a first valve outer periphery 931 that forms the 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, 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 the flow path portion in the valve device.

As shown in FIG. 5 , the first valve outer periphery 931 is formed with a first outer periphery opening 934 that connects the first flow path portion 961 to the first outlet port 261 via the first seal opening 581 when the shaft 92 rotates. The first valve 93 allows fluid that has flowed into the first flow path portion 961 to flow out from the first outlet port 261 by connecting the first outer periphery opening 934 to the first outlet port 261. The first outer periphery opening 934 formed in the first valve outer periphery 931 corresponds to the outer periphery opening formed on the valve outer periphery. The first outer periphery opening 934 is formed on the first valve outer periphery 931 and extends circumferentially around the axis of the shaft 92. The flow rate of fluid flowing out of the device from the first valve 93 is adjusted depending on 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.

As shown in FIG. 5, the second valve 94 has a second valve outer periphery 941 that forms the 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 on one side in the axial direction DRa, which allows fluid to flow into the second flow path portion 962. The second valve 94 is configured so that 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 the flow path portion in the valve device.

As shown in FIG. 5, the second valve outer periphery 941 is formed with a second outer periphery opening 944 that connects the second flow path portion 962 to the second outlet port 262 via the second seal opening 582 when the shaft 92 rotates. The second valve 94 allows fluid that has flowed into the second flow path portion 962 to flow out from the second outlet port 262 by connecting the second outer periphery opening 944 to the second outlet port 262. The second outer periphery opening 944 formed in the second valve outer periphery 941 corresponds to the outer periphery opening formed on the valve outer periphery.

The second outer peripheral opening 944 is formed to extend circumferentially about the axis of the shaft 92. The flow rate of fluid flowing from the second valve 94 to the outside of the device is adjusted according to the area of overlap between the second outer peripheral opening 944 and the second seal opening 582 when the shaft 92 rotates. The second inner opening 946 functions as a communication passage connecting 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 connecting portion 914 is used to connect the first valve 93 and the second valve 94. The cylindrical connecting portion 914 forms a first inter-valve space 97 between the outer periphery of the cylindrical connecting portion 914 and the inner circumferential surface of the housing. The first flow path portion 961 and the second flow path portion 962 are in communication via the first inter-valve space 97.

The second valve 94 has a shaft connection portion 916 located approximately in the center of its interior, which covers the outer periphery of the shaft 92. The second valve 94 has a cylindrical valve connection portion 915 connected to the other side of the second valve outer periphery 941 in the axial direction DRa. The second valve 94 is configured to allow fluid that has flowed into the second flow path portion 962 to flow into the third valve 95 via the cylindrical valve connection portion 915.

A second inter-valve space 98 is formed inside the cylindrical valve connection portion 915. The second inter-valve space 98 is connected to the second flow path portion 962 and the third flow path portion 963. The outer diameter of the cylindrical valve connection portion 915 on one side in the axial direction DRa 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 outer diameter of the cylindrical valve connection portion 915 on the other side in the axial direction DRa 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 portion 915 is formed to be continuous with the second valve outer periphery portion 941 and the third valve outer periphery portion 951.

As shown in FIG. 5, 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, 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 the flow path portion in the valve device.

As shown in FIG. 5, the third valve outer periphery 951 is formed with a third outer periphery opening 954 that connects the third flow path portion 963 to the third outlet port 263 via the third seal opening 583 when the shaft 92 rotates. By connecting the third outer periphery opening 954 to the third outlet port 263, the third valve 95 allows fluid that has flowed into the third flow path portion 963 to flow out of the device from the third outlet port 263. The third outer periphery opening 954 formed in the third valve outer periphery 951 corresponds to the outer periphery opening formed on the valve outer periphery.

The third outer peripheral opening 954 is formed on the third valve outer peripheral portion 951, extending circumferentially around the axis. The flow rate of fluid flowing from the third valve 95 to the outside of the device is adjusted according to the area of overlap between the third outer peripheral opening 954 and the third seal opening 583 when the shaft 92 rotates. The shaft connection portion 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 portion 916 transmits the rotational force of the shaft 92 to the valve 90 via the shaft connection portion 916. The shaft connection portion 916 is formed extending from the second valve 94 to the third valve 95 toward the other side in the axial direction DRa.

The operation of the water supply valve 15 will now be described. The microcomputer 330 calculates the rotation angle of the valve 90 required to supply the required flow rate of water to the distribution tube 136, i.e., the rotation angle of the motor 71. The microcomputer 330 transmits information about the calculated rotation angle of the motor 71 to the water supply valve 15. At this time, blocking members are attached to the two fluid outlets that are not connected to the distribution tube 136. The calculation of the rotation angle of the motor 71 may be performed by the information processing and calculation device 610 of the integrated calculation unit 600.

The water supply valve 15 rotates the motor 71 based on the rotation angle information received from the microcomputer 330. By rotating the motor 71, the water supply valve 15 rotates the valve 90 via the gear portion 72 and shaft 92, causing the required flow rate of fluid to flow out from the first outer peripheral opening 934, the second outer peripheral opening 944, and the third outer peripheral opening 954.

For example, we will explain the case where the first outlet port 261 is used as the fluid outflow portion that communicates with the distribution tube 136. The water supply valve 15 rotates the valve 90 to communicate the first outer peripheral opening 934 of the first valve 93 with the first outlet port 261. The water supply valve 15 adjusts the overlapping area between the first outer peripheral opening 934 and the first seal opening 581 by adjusting the rotational position of the valve 90. The water supply valve 15 directs fluid that has flowed into the valve housing space 23 from the inlet port 251 into the first flow path portion 961 via the first inner opening 936, and then flows out from the first outer peripheral opening 934 to the first outlet port 261. The microcomputer 330 controls the valve opening, which is the overlapping area between the first outer peripheral opening 934 and the first seal opening 581, to control the splash distance of irrigation water and supply irrigation water to the required location.

For example, we will explain the case where the second outlet port 262 is used as the fluid outlet port that communicates with the distribution tube 136. The water supply valve 15 rotates the valve 90 to connect the second outer peripheral opening 944 of the second valve 94 to the second outlet port 262. The water supply valve 15 adjusts the overlapping area between the second outer peripheral opening 944 and the second seal opening 582 by adjusting the rotational position of the valve 90. The water supply valve 15 directs fluid that has flowed into the valve housing space 23 from the inlet port 251 into the second flow path portion 962 via the second inner opening 946, and then flows out from the second outer peripheral opening 944 to the second outlet port 262. The microcomputer 330 controls the valve opening, which is the overlapping area between the second outer peripheral opening 944 and the second seal opening 582, to control the splash distance of irrigation water and supply it to the desired location.

For example, we will explain the case where the third outlet port 263 is used as the fluid outlet port that communicates with the distribution tube 136. The water supply valve 15 rotates the valve 90 to connect the third outer peripheral opening 954 of the third valve 95 to the third outlet port 263. The water supply valve 15 adjusts the overlapping area between the third outer peripheral opening 954 and the third seal opening 583 by adjusting the rotational position of the valve 90. The water supply valve 15 directs fluid that flows into the valve housing space 23 from the inlet port 251 into the third flow path portion 963 via the second flow path portion 962 of the second valve 94, and then outflows from the third outer peripheral opening 954 to the third outlet port 263. The microcomputer 330 controls the valve opening, which is the overlapping area between the third outer peripheral opening 954 and the third seal opening 583, to control the splash distance of irrigation water and supply irrigation water to the desired location. The control of these valve openings may be performed by the information processing and calculation device 610 of the integrated calculation unit 600.

The water supply valve 15 adjusts the rotation angle of the motor 71 by having the rotation angle sensor 73 detect the rotation angle of the third gear 723 and feeding back information about the detected rotation angle to the microcomputer 330.

The relationship between the rotation angle of the shaft 92 and the flow rate of the valve device will be explained with reference to the graph in Figure 6. In Figure 6, 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 Figure 6, FO1 represents the first valve 93, FO2 represents the second valve 94, and FO3 represents the third valve 95. In Figure 6, FS represents a fully open valve position, FC represents a fully closed valve position, and MO represents an intermediate valve position. The intermediate position is an opening between the fully closed and fully open positions. The solid line in Figure 6 shows the relationship between the rotation angle and the flow rate of the fluid flowing out of the third valve 95. The dashed line in Figure 6 shows the relationship between the rotation angle and the flow rate of the fluid flowing out of the second valve 94. The dashed line in Figure 6 shows the relationship between the rotation angle and the flow rate of the fluid flowing out of the first valve 93.

As shown in Figure 6, when the rotation angle is near 0 degrees, the third valve 95 is fully open and the other valves are fully closed, with fluid flowing out of the device only through the third valve 95. As the rotation angle is increased from this state, the third valve 95 transitions to an intermediate opening, and as the rotation angle is further increased, all three valves become fully closed.

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 both the first valve 93 and the second valve 94 are fully open. When the rotation angle is increased from this state, the second valve 94 transitions to a fully closed state via an intermediate opening, and both the second valve 94 and the third valve 95 are fully closed. 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 fully closed.

As described above, the opening degree of each valve changes depending on the rotation angle, changing the fluid flow rate from each valve. Each water supply valve 15 in the irrigation system 10 is configured to supply fluid from only one of the three valves, controlling the water splash distance and water supply amount to the field 20 depending on the rotation angle.

Next, the operation of the irrigation system 10 for irrigating plants while minimizing adverse effects on plant growth will be described using Figures 7 to 10. Figure 7 shows an example of a water supply path equipped with a water supply valve, a water pressure sensor, and a water temperature sensor, as well as a soil temperature sensor and a soil sensor. The irrigation system 10 shown in Figure 7 includes a water supply valve 15, a water pressure sensor 14, a water temperature sensor 160, and other components provided in a passage on one end of a plurality of aligned distribution tubes 136. Each distribution tube 136 is positioned so that irrigation water can be discharged to the corresponding furrow through a plurality of through-holes. The passage on one end connects one end of the distribution tube 136 to a vertical pipe 133 through which water from a water supply source flows. The first water supply valve controls the pressure of the water flowing from one end of the distribution tube 136 to the other end. The first water supply valve includes a water supply valve 150 and a plurality of water supply valves 151.

The vertical pipe 133 is connected to a passage leading to the inlet port 251 of each water supply valve. 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. In this case, the other fluid outlet sections, the second pipe section 52 and the third pipe section 53, are blocked by blocking members. The signal output unit 332 outputs a control signal to the water supply valve that controls the valve opening through feedback control using water supply information detected at the downstream end. The signal output unit 332 outputs a control signal to the water supply valve that controls the valve opening through feedback control using water supply information detected in the upstream passage.

The vertical pipe 133 is connected to multiple passages that lead to one ends of multiple distribution tubes 136. The vertical pipe 133 is provided with a water supply valve 150 that opens and closes the passage upstream of the connection with the first connecting pipe 134. The multiple passages include multiple branch pipes 134a that branch off to one ends of two adjacent distribution tubes 136. The multiple branch pipes 134a form multiple passages that branch off from the first connecting pipe 134. The first connecting pipe 134 is connected to the vertical pipe 133 at an upstream location and to the branch pipe 134a at a downstream location.

The multiple branch pipes 134a are passages connecting the multiple distribution tubes 136 and the first connecting pipe 134. Each branch pipe 134a connects one end of two adjacent distribution tubes 136 to the first connecting pipe 134. A water supply valve 151 is provided downstream of the branch pipes 134a. One branch pipe 134a is configured to supply water downstream to a predetermined number of distribution tubes 136 that make up a group. Note that one branch pipe 134a may connect to one or three or more distribution tubes 136. In other words, the predetermined number may be one or three or more. The first connecting pipe 134 is provided with one or more drain valves 152 that open and close the passage downstream of the connection with the branch pipe 134a. When the drain valve 152 is open, water inside the first connecting pipe 134 and other components can be discharged to the outside through the drain valve 152.

The water supply valve 151 has one fluid inlet and two fluid outlets, and can control the opening degree of each of the two branching passages. The water supply valve 151 opens and closes the passage downstream of the first connecting pipe 134, and controls the flow rate of water flowing down to a predetermined number of distribution tubes 136 that make up one group. The irrigation system 10 can irrigate multiple groups simultaneously by controlling the valve opening degree of the water supply valve 150 and each water supply valve 151.

The vertical pipe 133 is provided with a water pressure sensor 140 that detects the water supply pressure in a passage upstream of the connection with the first connecting pipe 134. The vertical pipe 133 is provided with a water temperature sensor 160 that detects the water supply temperature in a passage upstream of the connection with the first connecting pipe 134. The water pressure sensor 141 detects the water supply pressure at a portion of the first connecting pipe 134 that is upstream of the branch pipe 134a. The water pressure sensor 142 detects the water supply pressure at a portion upstream of the through-holes in each distribution tube 136. The control device 200 can determine the flow rate at each section using the water supply pressures detected by the water pressure sensors 140, 141, and 142.

A soil sensor 311 and a soil temperature sensor 312 are installed on the ridges corresponding to a predetermined number of distribution tubes 136 that make up one group. In the irrigation system 10 shown in Figure 7, the soil sensor 311 and the soil temperature sensor 312 are installed for the soil that is irrigated by one group of distribution tubes 136. The soil sensor 311 and the soil temperature sensor 312 may also be installed for each distribution tube 136. This configuration allows for more accurate detection of soil moisture content and soil temperature.

As shown in FIG. 2 , the water supply pressure detected by water pressure sensors 140, 141, and 142 is output to microcomputer 330 of monitoring unit 300. The soil temperature detected by soil temperature sensor 312 is output to microcomputer 330. The water temperature detected by water temperature sensor 160 is output to microcomputer 330. Processing unit 334 compares the soil temperature detected by soil temperature sensor 312 with the water temperature in the water supply path detected by water temperature sensor 160 to determine whether or not to perform irrigation. Processing unit 334 determines whether or not to perform irrigation based on the water temperature in the water supply path detected by water temperature sensor 160. Signal output unit 332 outputs control signals to control the valve opening to water supply valves 150, 151 and drain valve 152, respectively, based on the result of the determination of whether or not to perform irrigation. The valve opening control described here may be performed by information processing and calculation equipment 610 of integrated calculation unit 600.

In the irrigation process according to Figures 8 to 10 and in the irrigation process described in the second embodiment and thereafter, the soil temperature and the water temperature in the water supply path can be replaced as follows. The soil temperature may be replaced with the soil temperature detected by the soil temperature sensor 312. This soil temperature includes not only the temperature of the soil but also the temperature of non-soil surfaces, such as natural turf fields and artificial turf fields. Soil also includes the soil type of orchards. The water temperature in the water supply path detected by the water temperature sensor 160 may be replaced with the temperature of the water supply path detected by a temperature sensor. The temperature of the water supply path includes not only the water temperature but also the temperature of the piping and other components that make up the water supply path. Therefore, the processing unit 334 compares the soil temperature detected by the soil temperature sensor 312 with the temperature of the water supply path to determine whether to perform irrigation. The processing unit 334 determines whether to perform irrigation depending on the temperature of the water supply path.

When performing irrigation treatment, the irrigation system 10 executes processing according to the flowcharts shown in Figures 8 to 10. Each of Figures 8 to 10 is a flowchart showing an example of operation when an irrigation command is issued. The processing shown in Figure 8, the processing shown in Figure 9, and the processing shown in Figure 10, which will be described below, are executed in parallel when the irrigation treatment is carried out. Alternatively, the irrigation system 10 may be configured so that the control device 200 executes at least one of these processes. The control device 200 executes the processing shown in Figure 8, the processing shown in Figure 9, and the processing shown in Figure 10, for example, using the monitoring unit 300 or the integrated calculation unit 600. Below, we will explain an example in which the monitoring unit 300 executes each process as a representative.

The integrated calculation unit 600 outputs an irrigation command to the monitoring unit 300 corresponding to the divided area where irrigation is to be performed. In this state, the drain valve 152 and the water supply valve 150 are controlled to a closed state. The microcomputer 330 of the monitoring unit 300 receives a signal related to the irrigation process output from the integrated calculation unit 600 and executes the process shown in FIG. 8. The process shown in FIG. 8 is executed when the irrigation time arrives or when an irrigation command is output, and is repeated, for example, several times a day. The process shown in FIG. 8 is executed, for example, in early spring or late autumn. The acquisition unit 331 acquires the soil temperature detected by the soil temperature sensor 312 and the water temperature in the water supply path detected by the water temperature sensor 160. In step S100, the processing unit 334 determines whether the detected soil temperature is equal to or lower than the detected water temperature. In this specification, the soil temperature detected by the soil temperature sensor 312 may be referred to as "soil temperature."

If the detected soil temperature is equal to or lower than the detected water temperature, the microcomputer 330 executes a process to perform irrigation in step S120. The microcomputer 330 outputs a control signal to open the water supply valves 151 corresponding to the divided areas to be irrigated. The microcomputer 330 also outputs a control signal to close the water supply valves 151 corresponding to the divided areas not to be irrigated. Irrigation from the distribution tube 136 located downstream of the water supply valve 151 controlled to the open state is initiated by controlling the valve opening to achieve the target irrigation amount and target water throw distance. Note that in this state, the pump 110 is operating, and water supplied from the water supply source flows down the water supply piping 130. Step S120 causes the water to flow simultaneously from one end of the distribution tube 136 to the other, and irrigation is performed by discharging water from each through-hole toward the ridges.

This irrigation continues until the processing unit 334 determines in step S125 that the irrigation termination condition is met. The irrigation termination condition is met, for example, when the irrigation flow rate from the start of irrigation reaches the target irrigation amount. The irrigation termination condition is met, for example, when the irrigation time from the start of irrigation reaches the target irrigation time. If it is determined in step S125 that the irrigation termination condition is met, the microcomputer 330 controls the first water supply valve to a fully closed state, thereby terminating irrigation by supplying water from one end to the other end. This ends the flowchart shown in Figure 8.

If the detected soil temperature exceeds the detected water temperature, the processing unit 334 determines in step S110 whether the detected water temperature is equal to or greater than the first threshold. If the detected water temperature is equal to or greater than the first threshold, the processing unit 334 executes step S120 described above to perform irrigation until the aforementioned termination condition is met. In this case, irrigation is performed because the water temperature is not so low that it inhibits plant growth. The first threshold is an irrigation suppression threshold used to determine whether irrigation should be prohibited. In step S120, the irrigation amount may be controlled to be greater than the amount in step S115.

If the detected water temperature is below the first threshold, the microcomputer 330 executes a process in step S115 to not perform irrigation, and then ends the flowchart. The microcomputer 330 outputs a control signal to control all water supply valves 151 to a closed state. Alternatively, the microcomputer 330 outputs a control signal to close the water supply valve 150. This blocks the water supply path located upstream of the water supply valve 151 from the distribution tube 136, preventing low-temperature water in the piping from being discharged onto the plants. In step S115, rather than not performing irrigation, the amount of irrigation may be controlled to be reduced below the amount of irrigation in step S120. This helps reduce the amount of low-temperature water in the piping discharged onto the plants.

When the detected soil temperature exceeds the detected water temperature, the temperature of the water in the water supply path is even lower than the soil temperature. If such low-temperature water is sprayed onto the plants, it will cause them to fail to take root, resulting in a lower yield when the plants are shipped.

The first threshold is stored in the memory unit 333. The first threshold is set, for example, based on past actual values, to a low temperature that is lower than the soil temperature and that is likely to inhibit plant growth. For example, the first threshold is a value set based on past actual values of soil temperature and water temperature data that can predict growth inhibition based on the type of plant. This first threshold is set to a growth inhibition temperature that is lower than the soil temperature and that can predict growth inhibition based on the type of plant. The growth inhibition temperature is, for example, a temperature that is lower than the soil temperature and that will cause poor plant establishment.

The irrigation system 10 can automatically and forcibly stop irrigation if the water temperature in the piping of the water supply path falls below this first threshold value at the time of irrigation. The irrigation system 10 can automatically cancel the irrigation stop and resume irrigation if the water temperature in the piping of the water supply path rises above the first threshold value or exceeds the soil temperature. The irrigation system 10 can also automatically resume irrigation if the water temperature in the piping rises above the first threshold value or exceeds the soil temperature at the next or subsequent irrigation time. By performing the process shown in Figure 8 multiple times throughout the day at each irrigation time, the irrigation system 10 can postpone inappropriate irrigation until the air or water temperature rises. By postponing irrigation until the air temperature rises, the irrigation system 10 contributes to preventing irrigation that is inappropriate for plant growth when the water temperature is low, such as in the mornings or evenings of early spring.

In addition, the first threshold value does not have to be a value stored in the memory unit 333, but may be input by the user to the integrated calculation unit 600 by operating the input device 800. In this case, the first threshold value can be set at any time based on the user's experience, etc., and an irrigation system 10 can be provided that can control the suspension and implementation of irrigation according to conditions appropriate to the local climate and environment.

Next, the processing shown in Figure 9 will be described. Upon receiving a signal related to the irrigation processing output from the integrated calculation unit 600, the microcomputer 330 executes the processing shown in Figure 9. The processing shown in Figure 9 is executed when the irrigation time arrives or when an irrigation command is output, and is repeated, for example, several times a day. The acquisition unit 331 acquires the temperature of the water in the water supply path detected by the water temperature sensor 160. In step S200, the processing unit 334 determines whether the detected value of the water temperature in the water supply path is equal to or greater than a second threshold. The second threshold is set to a value higher than the first threshold and is stored in the memory unit 333. The processing shown in Figure 9 is executed, for example, in the summer. The second threshold is a water temperature that may cause root damage to plants and is a drainage threshold used to determine whether to drain water.

If the detected water temperature is below the second threshold, the microcomputer 330 proceeds to step S250 and executes a process to perform irrigation. If the detected water temperature is equal to or greater than the second threshold, in step S210, the microcomputer 330 outputs a control signal to open the drain valve 152 installed in the first connecting pipe 134. Furthermore, in step S220, the microcomputer 330 outputs a control signal to open the water supply valve 150 (also called the water source valve) installed upstream of the first connecting pipe 134. As a result of the processing of these steps, in step S230, stagnant water in the piping of the water supply path is discharged to the outside through the opened drain valve 152 and is not discharged onto the plants. In addition, water stagnant in the distribution tube 136 can also be discharged to the outside through the opened drain valve 152 because pressure is released to the opened drain valve 152.

Stagnant water in the piping of the water supply path is drained after a predetermined time has elapsed, and the microcomputer 330 outputs a control signal to close the drain valve 152 in step S240. This ends the drainage process. Next, step S250 is executed to perform irrigation, and if the determination process in step S260 is successful, irrigation is completed and this flowchart ends. Steps S250 and S260 are similar to steps S120 and S125 in Figure 8, respectively.

When the temperature of the water stagnating in the pipes is above the second threshold, the air or soil temperature is high, and if this water is sprayed onto the plants, it will cause root damage, resulting in a lower yield at plant shipments. The second threshold is set, for example, based on past actual values, to a temperature higher than the first threshold and likely to inhibit plant growth. For example, the second threshold is a value set based on past actual soil temperature values and water temperature data that can predict root damage and other growth inhibition based on the type of plant. For example, the second threshold is set to a growth inhibition temperature that is above a predetermined temperature below soil temperature or above soil temperature and can predict growth inhibition based on the type of plant. This growth inhibition temperature is, for example, a temperature that is lower than soil temperature and will cause root damage to plants.

The irrigation system 10 can automatically and forcibly drain water if the water temperature in the piping of the water supply path is equal to or higher than this second threshold when irrigation is performed. If the water temperature in the piping of the water supply path exceeds the second threshold, the irrigation system 10 can automatically drain stagnant water and then perform irrigation.

Furthermore, if the amount of stagnant water in the piping exceeds a second threshold, the irrigation system 10 may automatically drain the stagnant water and then postpone irrigation until the amount of stagnant water in the piping falls below the second threshold. By performing the process shown in FIG. 9 multiple times each day at the appropriate time for irrigation, the irrigation system 10 can prevent inappropriate irrigation until the air and water temperatures drop. The irrigation system 10 contributes to preventing irrigation that is inappropriate for plant growth when the water temperature is high, such as in the summer or during the day.

In addition, the second threshold value does not have to be a value stored in the memory unit 333, but may be input by the user to the integrated calculation unit 600 by operating the input device 800. In this case, the second threshold value can be set at any time based on the user's experience, etc., and an irrigation system can be provided that can control drainage and the suspension or implementation of irrigation according to conditions suitable for the local climate, etc.

Next, the processing shown in Figure 10 will be described. The microcomputer 330 receives a signal related to the irrigation processing output from the integrated calculation unit 600 and executes the processing shown in Figure 10. The processing shown in Figure 10 is executed when the irrigation time arrives or when an irrigation execution command is output, and is repeated several times throughout the day, for example. The processing shown in Figure 10 may also be configured to be executed at a predetermined time throughout the day. The processing shown in Figure 10 may also be configured to be executed a predetermined time before the irrigation execution timing.

First, the acquisition unit 331 acquires the temperature of the water in the water supply path detected by the water temperature sensor 160. In step S300, the processing unit 334 determines whether the detected value of the water temperature in the water supply path is equal to or lower than a third threshold. The third threshold is set to a value lower than the first threshold and is stored in the memory unit 333. The process shown in FIG. 10 is performed, for example, in winter when water may freeze. The third threshold is set to a temperature higher than the freezing temperature of water and is a pre-freeze threshold for determining whether to drain the water before it freezes.

If the detected water temperature value exceeds the third threshold, the microcomputer 330 ends this flowchart. If the detected water temperature value is equal to or less than the third threshold, in step S310, the microcomputer 330 outputs a control signal to open the drain valve 152 installed in the first connecting pipe 134. Furthermore, in step S320, the microcomputer 330 outputs a control signal to open irrigation valves such as the water supply valve 151 installed downstream of the first connecting pipe 134. Through these processes, stagnant water accumulated in the water supply path is discharged to the outside through the opened drain valve 152, and water is not discharged onto the plants. After a predetermined time has elapsed, the discharge of stagnant water in the piping is completed. This ends this flowchart.

If the temperature of the water stagnating in the pipes is below the third threshold, there is a possibility that the stagnant water will freeze in the future. The third threshold is set, for example, based on past actual water temperature and air temperature values, to a temperature at which the stagnant water in the pipes is likely to freeze by the time the next irrigation is scheduled. The third threshold is set, assuming that the air temperature will continue to drop, to a value that will allow the stagnant water to be drained from the pipes and the drainage process to be completed before it freezes. The third threshold is a value set based on past actual air and water temperatures. The third threshold is set, for example, to a temperature that is a predetermined temperature higher than 0°C, the temperature at which water begins to freeze.

The irrigation system 10 can automatically and forcibly drain the water if the temperature of the stagnant water in the pipes is below this third threshold when irrigation is to be performed. If the temperature of the stagnant water in the pipes falls below the third threshold, which indicates the possibility of future freezing based on future changes in air temperature and the freezing temperature of water, the irrigation system 10 automatically drains the water regardless of the relationship between soil and water temperatures. This eliminates the frozen state when irrigation is next performed, allowing for smooth irrigation and preventing pipe damage due to freezing.

The irrigation system 10 prepares the pipes for smooth irrigation the next time it is used by removing water from the pipes before the stagnant water freezes, such as in winter evenings or at night. If the water temperature is below the pre-freeze threshold at the time of irrigation, the control device drains the stagnant water in the water supply line without releasing it to the plants, regardless of the relationship between the soil temperature and the water temperature. If the water temperature is below the pre-freeze threshold or above the drainage threshold at the time of irrigation, the control device drains the stagnant water in the water supply line without releasing it to the plants.

In addition, the third threshold value does not have to be a value stored in the memory unit 333, but may be input by the user to the integrated calculation unit 600 by operating the input device 800. This system can set the third threshold value at any time based on the user's experience and meteorological information, enabling smooth irrigation and pipe protection the next time according to conditions appropriate to the local climate, etc.

The irrigation system 10 of the first embodiment includes a water supply path through which irrigation water is supplied for release to plants, a temperature sensor that detects the temperature of the water supply path, and a soil temperature sensor 312 that detects soil temperature. The irrigation system 10 also includes a control device 200 that controls the amount of irrigation water using the soil temperature detected by the soil temperature sensor and the temperature detected by the temperature sensor.

This system allows for control by varying the amount of irrigation water depending on whether the temperature of the water supply path is high or low relative to the soil temperature. If the water supply temperature is predicted to have a negative impact on plant growth, this system can provide irrigation that minimizes the negative impact.

The control device 200 controls the amount of irrigation water to be reduced if the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below the irrigation suppression threshold at the time of irrigation. Furthermore, if the soil temperature does not exceed the temperature of the water supply path or if the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold, the control device 200 controls the amount of irrigation water to be increased more than when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below the irrigation suppression threshold.

This system can reduce the amount of irrigation water when the temperature in the water supply line is low and has not yet risen to the soil temperature, and can suppress irrigation until the water temperature rises. On the other hand, when the soil temperature does not exceed the temperature in the water supply line, it can provide an amount of irrigation water that promotes growth while minimizing negative effects on plant growth.

The irrigation system 10 is equipped with a control device that determines whether to perform irrigation using the soil temperature detected by the soil temperature sensor 312 and the temperature of the water supply path. The control device 200 prohibits irrigation if, at the timing of irrigation, the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below the irrigation suppression threshold. The control device 200 performs irrigation if the soil temperature does not exceed the temperature of the water supply path, or if the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold.

This system can prevent irrigation when the temperature in the water supply line is low and has not yet risen to the soil temperature, and can postpone irrigation until the temperature in the water supply line rises. On the other hand, when the conditions for irrigation are met as described above, it can provide an appropriate supply of moisture that promotes growth while minimizing negative effects on plant growth.

When it is time to irrigate, if the temperature in the water supply path exceeds the drainage threshold, the control device 200 drains the stagnant water in the water supply path without releasing it to the plants, and then irrigates. If the temperature in the water supply path falls below the drainage threshold, the control device 200 irrigates with stagnant water. The control device 200 can perform this control even if the time to irrigate has not yet arrived.

With this system, when the temperature of the water supply path exceeds the drainage threshold, high-temperature stagnant water can be drained without being released onto the plants, and then irrigation at an appropriate temperature can be carried out. On the other hand, when the temperature of the water supply path falls below the drainage threshold, irrigation containing stagnant water at an appropriate temperature can be carried out, achieving an appropriate supply of moisture that promotes growth while minimizing adverse effects on plant growth.

The control device includes a processing unit 334 that determines whether to perform irrigation using the temperature of the water supply path through which irrigation water is supplied and the soil temperature of the field, and a signal output unit 332. The signal output unit 332 outputs a signal prohibiting irrigation when the processing unit 334 determines that the soil temperature exceeds the temperature of the water supply path and that the temperature of the water supply path is below the irrigation suppression threshold at the time of irrigation. The signal output unit 332 outputs a signal prohibiting irrigation when the processing unit 334 determines that the soil temperature does not exceed the temperature of the water supply path. The signal output unit 332 outputs a signal to perform irrigation when the processing unit determines that the soil temperature does not exceed the temperature of the water supply path or that the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold.

This control device can suppress irrigation when the temperature of the water supply path is low and has not yet risen to the soil temperature, and can postpone irrigation until the temperature of the water supply path rises. On the other hand, this control device will irrigate when the temperature of the water supply path is higher than the soil temperature, or when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold. This combined control of irrigation prohibition and irrigation implementation allows for an appropriate supply of moisture to promote growth while minimizing adverse effects on plants.

The control device includes a processing unit 334 that determines whether to perform irrigation using the temperature of the water supply path through which irrigation water is being supplied, and a signal output unit 332. The signal output unit 332 outputs a signal to drain stagnant water in the water supply path when the processing unit 334 determines that the temperature of the water supply path exceeds the drainage threshold at the time irrigation is to be performed. The signal output unit 332 then outputs a signal to perform irrigation. The signal output unit 332 outputs a signal to perform irrigation including stagnant water when the processing unit 334 determines that the temperature of the water supply path is below the drainage threshold at the time irrigation is to be performed.

When the temperature of the water supply path exceeds the drainage threshold, this control device can drain high-temperature stagnant water without releasing it onto the plants, and then irrigate at an appropriate temperature. On the other hand, when the temperature of the water supply path falls below the drainage threshold, this control device irrigates with stagnant water at an appropriate temperature. This combined control of drainage and irrigation allows for an appropriate supply of moisture that promotes growth while minimizing adverse effects on plant growth.

Second Embodiment A second embodiment will be described with reference to Figures 11 and 12. The irrigation system 10 of the second embodiment differs from the first embodiment in that it includes a weather sensor 313 instead of the water temperature sensor 160 shown in Figure 7. The configurations, actions, and effects of the second embodiment that are not specifically described are the same as those of the above-described embodiments, and only the differences will be described below.

The weather sensor 313 shown in Figures 11 and 12 is specifically a sensor that detects information related to air temperature and solar radiation. The control device 200 acquires the detection value of the weather sensor 313 and uses this detection value to estimate the water temperature in the piping of the water supply path. The control device 200 uses this estimated water temperature value in place of the detected water temperature value in each of the processes in Figures 8 to 10. The control device 200 calculates the estimated water temperature in the piping from the characteristic data stored in the memory unit 333 and the detection value of the weather sensor 313. The characteristic data is data that indicates the correlation between water temperature information and information related to air temperature and solar radiation. The control device 200 may also be configured to acquire characteristic data from an external source via the integrated communication unit 400.

In addition, the control device 200 may be configured to obtain a weather forecast from an external source instead of the detected value of the water temperature sensor 160 shown in Figure 7, and estimate the water temperature from the weather forecast data.

Third Embodiment A third embodiment will be described with reference to Fig. 13. The irrigation system 10 of the third embodiment executes processing according to the flowchart shown in Fig. 13 when performing irrigation treatment. The irrigation system 10 of the third embodiment differs from the first embodiment in that it executes the processing shown in Fig. 13 instead of the processing shown in Fig. 8 of the first embodiment. The configurations, actions, and effects of the third embodiment that are not specifically described are the same as those of the above-described embodiments, and only the differences will be described below.

The control device 200 executes the processes shown in FIG. 13, FIG. 9, and FIG. 10, for example, using the monitoring unit 300 and the integrated calculation unit 600. The process shown in FIG. 13 differs from the process shown in FIG. 8 only in step S400. Therefore, steps S410, S420, S425, S430, and S435 are the same as steps S100, S110, S115, S120, and S125, respectively. In other words, in the process shown in FIG. 13, the determination process of step S400 is executed before executing the process corresponding to FIG. 8.

The microcomputer 330 of the monitoring unit 300, which receives the signal related to the irrigation process output from the integrated calculation unit 600, executes the process shown in Figure 13. The process shown in Figure 13 is executed when the irrigation time arrives or when an irrigation command is output, and is repeated, for example, several times a day. The process shown in Figure 13 is executed, for example, in early spring or late autumn. The acquisition unit 331 acquires the soil moisture content detected by the soil sensor 311. In step S400, the processing unit 334 determines whether the detected soil moisture content is equal to or less than a fourth threshold value.

If the detected soil moisture content exceeds the fourth threshold, this flowchart ends without irrigation. If the detected soil moisture content is equal to or less than the fourth threshold, the determination process of step S410 is executed. Subsequently, steps S100, S110, S115, S120, and S125, which are the same processes as those in Figure 8, are executed.

When the soil moisture content exceeds the fourth threshold, there is enough moisture in the soil that the plants can absorb, so there is no need to water them any more. If the plants are watered in this state, the soil will become overhydrated, which will have a negative impact on growth and result in a lower yield of plants when shipped.

The fourth threshold is stored in the memory unit 333. The fourth threshold is, for example, a growth inhibition threshold based on past actual values, at which the soil moisture content is likely to inhibit plant growth if irrigation is performed. For example, the fourth threshold is a value set based on past actual values of soil moisture content and irrigation volume, and soil moisture content data that can predict growth inhibition based on the type of plant.

The irrigation system 10 can automatically and forcibly prohibit irrigation if the soil moisture content exceeds this fourth threshold at the time of irrigation. If the soil moisture content falls below the fourth threshold, the irrigation system 10 can automatically cancel the irrigation prohibition and transition to determining whether irrigation is necessary. Furthermore, if the soil moisture content falls below the fourth threshold at the next or subsequent irrigation time, the irrigation system 10 can automatically transition from the irrigation prohibition state to determining whether irrigation is necessary. By performing this process multiple times each day at the time of irrigation, the irrigation system 10 can prohibit excessive irrigation and postpone inappropriate irrigation until the air or water temperature rises. The control device 200 forcibly prohibits irrigation if the soil moisture content exceeds the growth inhibition threshold before determining whether the soil temperature exceeds the water temperature.

In addition, the fourth threshold value does not have to be a value stored in the memory unit 333, but may be input by the user to the integrated calculation unit 600 by operating the input device 800. The irrigation system 10 can set the fourth threshold value at any time based on the user's experience, etc. This irrigation system 10 can both prohibit excessive irrigation and stop or start irrigation depending on the conditions appropriate to the local climate and environment.

Fourth Embodiment A fourth embodiment will be described with reference to Fig. 14. The irrigation system 10 of the fourth embodiment executes processing according to the flowchart shown in Fig. 14 when performing irrigation treatment. The irrigation system 10 of the fourth embodiment differs from the first embodiment in that it executes the processing shown in Fig. 14 instead of the processing shown in Fig. 9. The configurations, actions, and effects of the fourth embodiment that are not specifically described are the same as those of the first and third embodiments, and only the differences will be described below.

The control device 200 executes the processes shown in Figure 14, Figure 8, and Figure 10, for example, using the monitoring unit 300 and the integrated calculation unit 600. In other words, the process shown in Figure 14 can be replaced with the process shown in Figure 9 described in the first embodiment.

The microcomputer 330, which receives the signal related to the irrigation process output from the integrated calculation unit 600, executes the process shown in FIG. 14. The process shown in FIG. 14 is executed when the irrigation time arrives or when an irrigation command is output, and is repeated, for example, several times a day. The acquisition unit 331 acquires the soil moisture content detected by the soil sensor 311. In step S500, the processing unit 334 executes a determination process similar to that of step S400 described above. This determination process allows the irrigation system 10 of the fourth embodiment to achieve the same effects as those described in the third embodiment. For details of these effects, please refer to the third embodiment.

If the soil moisture content is below the fourth threshold, the processing unit 334 determines in step S510 whether the detected temperature of the water supply path is equal to or greater than the second threshold. The processing shown in FIG. 14 is performed, for example, during the summer.

If the detected temperature of the water supply path is below the second threshold, the microcomputer 330 proceeds to step S530 and executes a process to perform irrigation. If the detected temperature of the water supply path is equal to or greater than the second threshold, the microcomputer 330 outputs a control signal to open the drain valve 152 installed in the first connecting pipe 134 in step S510. This process causes stagnant water in the water supply path piping to be discharged to the outside through the opened drain valve 152, and water is not discharged onto the plants. Furthermore, stagnant water in the distribution tube 136 is also discharged to the outside through the opened drain valve 152, as pressure escapes to the opened drain valve 152.

Next, step S530 is executed to perform irrigation. This irrigation continues until the processing unit 334 determines in step S540 that the irrigation termination condition is met. This termination condition is the same as the termination condition in the first embodiment. If it is determined in step S540 that the irrigation termination condition is met, the microcomputer 330 controls the first water supply valve to a fully closed state, thereby terminating irrigation by supplying water from one end to the other. This ends the flowchart shown in Figure 14. By performing this process multiple times throughout the day at each irrigation timing, the irrigation system 10 can prohibit excessive irrigation and postpone inappropriate irrigation until the air or water temperature drops. The control device 200 forcibly prohibits irrigation if the soil moisture content exceeds the growth inhibition threshold before determining whether the temperature of the water supply path exceeds the drainage threshold.

Fifth Embodiment A fifth embodiment will be described with reference to Fig. 15. The irrigation system 10 of the fifth embodiment executes processing according to the flowchart shown in Fig. 15 when performing irrigation treatment. The irrigation system 10 of the fifth embodiment differs in that it executes processing of step S600 shown in Fig. 15 instead of processing of step S400 of the third embodiment. Configurations, actions, and effects not specifically described in the fifth embodiment are the same as those of the above-described embodiments, and only the differences will be described below.

The control device 200 executes the processes shown in FIG. 15, FIG. 9, and FIG. 10, for example, using the monitoring unit 300 and the integrated calculation unit 600. The process shown in FIG. 15 differs from the process shown in FIG. 13 only in step S600. Therefore, steps S610, S620, S625, S630, and S635 are the same as steps S100, S110, S115, S120, and S125 in FIG. 8, respectively. In other words, in the process shown in FIG. 15, the determination process of step S600 is executed before executing the process corresponding to FIG. 8.

The microcomputer 330 of the monitoring unit 300, which receives the signal related to the irrigation process output from the integrated calculation unit 600, executes the process shown in Figure 15. The process shown in Figure 15 is executed when the irrigation time arrives or when an irrigation execution command is output, and is repeated, for example, several times a day. The process shown in Figure 15 is executed, for example, in early spring or late autumn. In step S600, the processing unit 334 determines whether the timer set time has arrived.

If the processing unit 334 determines that the timer set time has not arrived, it ends this flowchart. If it determines that the timer set time has arrived, it executes the determination process of step S610. Thereafter, it executes steps S100, S110, S115, S120, and S125, which are the same processes as in Figure 8.

A signal indicating that the timer set time has arrived is output from the RTC 350 to the processing unit 334. When the processing unit 334 receives this signal, it determines that the timer set time has arrived. The timer set time is the time at which the soil temperature is detected, and is set in advance. The timer set time may also be input into the integrated calculation unit 600 by the user operating the input device 800. The irrigation system 10 can set the timer set time at any time based on the user's experience, etc.

Sixth Embodiment A sixth embodiment will be described with reference to Fig. 16. The irrigation system 10 of the sixth embodiment executes processing according to the flowchart shown in Fig. 16 when performing irrigation treatment. The irrigation system 10 of the sixth embodiment differs from the first embodiment in that it executes the processing shown in Fig. 16 instead of the processing shown in Fig. 8 of the first embodiment. The configurations, actions, and effects of the sixth embodiment that are not specifically described are the same as those of the above-described embodiments, and only the differences will be described below.

The control device 200 executes the processes shown in FIG. 16, FIG. 8, and FIG. 10, for example, using the monitoring unit 300 and the integrated calculation unit 600. The process shown in FIG. 16 differs from the process shown in FIG. 8 only in step S700. Therefore, steps S710, S720, S730, S740, S750, S760, and S770 are the same as steps S200, S210, S220, S230, S240, S250, and S260, respectively. In other words, in the process shown in FIG. 16, the determination process of step S700 is executed before executing the process corresponding to FIG. 9.

The process shown in FIG. 16 is executed when the irrigation time arrives or when an irrigation command is output, and is repeated, for example, several times a day. In step S700, the processing unit 334 executes a determination process similar to that of step S600 described above. This determination process allows the irrigation system 10 of the sixth embodiment to achieve the same effects as those described in the fifth embodiment. For details of these effects, please refer to the fifth embodiment.

Seventh Embodiment The seventh embodiment will be described with reference to Figures 17 and 18. The irrigation system 10 of the seventh embodiment differs from the first embodiment in the passage configuration on the other end side of the distribution tube 136. The configurations, actions, and effects of the seventh embodiment that are not specifically described are the same as those of the above-described embodiments, and only the differences will be described below.

The seventh embodiment of the irrigation system 10 shown in Figure 17 has a drainage passage downstream of the multiple distribution tubes 136. The other ends of the multiple distribution tubes 136 are connected to a second connecting pipe 137. The other ends of the distribution tubes 136 are also the downstream ends of the distribution tubes 136. The second connecting pipe 137 is connected to a single drainage pipe at its downstream location and to multiple branch pipes 137a at its upstream location. The multiple branch pipes 137a form multiple passages that merge into the second connecting pipe 137. Each branch pipe 137a connects the downstream ends of a predetermined number of distribution tubes 136 that make up a group to the second connecting pipe 137. The multiple branch pipes 137a are passages that connect the multiple distribution tubes 136 to the second connecting pipe 137.

A water supply valve 153 that opens and closes the passage is provided upstream of the branch pipe 137a. One branch pipe 137a is provided so that drainage water from a predetermined number of distribution tubes 136 that make up one group flows downstream. A drain valve 154 that opens and closes the passage is provided in the drainage pipe downstream of the second connecting pipe 137. When the drain valve 152 is open, water in the water supply path can be discharged to the outside through the distribution tube 136, the second connecting pipe 137, the branch pipe 137a, and the drain valve 154. The water supply valve 153 and drain valve 154 are second water supply valves that open and close the passage on the other end of the distribution tube 136.

The irrigation system 10 controls the valve opening of each water supply valve 151, causing the water supply valve 151 to function as a flow control valve, thereby supplying water at a low flow rate. Each distribution tube 136 has the characteristic of discharging water from each through-hole within a specified pressure range.

Figure 18 shows the control configuration of the seventh embodiment of the irrigation system 10. As described above, when stagnant water in the piping or when draining stagnant water, the microcomputer 330 outputs a control signal to open the water supply valve 151 connected to the drainage path out of the multiple water supply valves 151. At this time, the microcomputer 330 controls the valve opening of the water supply valve 151 so that the internal pressure is outside a predetermined pressure range that prevents water from being discharged from the distribution tube 136. The microcomputer 330 also outputs control signals to open the water supply valve 153 and drainage valve 154 connected to the drainage path. This allows the irrigation system 10 to drain stagnant water and other water from the water supply path to the outside from the other end of the distribution tube 136 while suppressing water discharge onto the ridges.

Eighth Embodiment An eighth embodiment will be described with reference to Fig. 19. The irrigation system 10 of the eighth embodiment differs from the previously described embodiments in the number of drain valves 152. The configurations, actions, and effects of the eighth embodiment that are not specifically described are the same as those of the previously described embodiments, and only the differences will be described below.

The eighth embodiment of the irrigation system 10 shown in Figure 19 has more drain valves 152 than the configuration shown in Figure 7. The eighth embodiment of the irrigation system 10 has one or more drain valves 152 that open and close the passages branching off from the branch pipe 134a. When this drain valve 152 is open, water inside the branch pipe 134a and other areas can be drained to the outside through the drain valve 152.

<Other Embodiments>
The disclosure of this specification is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and modifications thereto by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and elements shown in the embodiments, and various modifications can be made. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses the omission of parts and elements from the embodiments. The disclosure encompasses the substitution 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 defined by the claims, and should be interpreted as including all modifications within the meaning and scope of the claims.

The control device 200 may be configured to execute all of the processes shown in Figures 8, 9, and 10 in parallel when irrigation is performed. In this case, if the conditions for performing drainage or prohibiting irrigation are met in any of the processes, the control device 200 will execute the process for performing drainage or prohibiting irrigation accordingly.

The above-described embodiments may be configured to include a sensor device that integrates a water pressure sensor and a water temperature sensor, and to detect the water pressure and water temperature within the piping using this sensor device. The above-described embodiments may be configured to include a device that integrates various sensors and valves, and to detect various types of water supply information and open and close the passage using this device.

The apparatus and methods described herein may be implemented by a special-purpose computer comprising a processor programmed to perform one or more functions embodied in a computer program. Alternatively, the apparatus and methods described herein may be implemented by special-purpose hardware logic circuitry. Alternatively, the apparatus and methods described herein may be implemented by one or more special-purpose computers configured by a combination of a processor that executes a computer program and one or more hardware logic circuits. Additionally, a computer program may be stored as instructions executed by a computer on a computer-readable, non-transitory storage medium.

Disclosure of Technical Ideas This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be written in a multiple dependent form, where the subsequent clause alternatively cites the preceding clause. These multiple dependent clauses define multiple technical ideas.

Technical thought 1
a water supply channel through which irrigation water is supplied for release to the plants;
a temperature sensor (160) for detecting the temperature of the water supply path;
A soil temperature sensor (312) for detecting soil temperature;
a control device (200) that controls the amount of irrigation water using the soil temperature detected by the soil temperature sensor and the temperature detected by the temperature sensor;
An irrigation system comprising:

Technical thought 2
The control device, at the timing of performing irrigation,
When the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is lower than an irrigation suppression threshold, the amount of irrigation water is controlled to be reduced;
An irrigation system described in technical idea 1, which controls the amount of irrigation to be increased when the soil temperature does not exceed the temperature of the water supply path, or when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold, compared to when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below the irrigation suppression threshold.

Technical thought 3
The control device, at the timing of performing irrigation,
prohibiting irrigation when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below an irrigation suppression threshold;
An irrigation system described in technical idea 1, which performs irrigation when the soil temperature does not exceed the temperature of the water supply path, or when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold.

Technical thought 4
The control device
When the temperature of the water supply path exceeds a drainage threshold, stagnant water in the water supply path is drained without being released to the plant, and then irrigation is performed;
An irrigation system according to Technical Idea 1, which carries out irrigation containing stagnant water when the temperature of the water supply path falls below the drainage threshold.

Technical thought 5
The control device, at the timing of performing irrigation,
When the temperature of the water supply path exceeds a drainage threshold, stagnant water in the water supply path is drained without being released to the plant, and then irrigation is performed;
An irrigation system according to Technical Idea 1, which carries out irrigation containing stagnant water when the temperature of the water supply path falls below the drainage threshold.

Technical thought 6
The control device, at the timing of performing irrigation,
An irrigation system as described in Technical Idea 1, in which, when the temperature of the water supply path falls below a pre-freezing threshold set at a temperature higher than the freezing temperature of water, stagnant water in the water supply path is drained without being released to the plants, regardless of the relationship between the ground temperature and the temperature of the water supply path.

Technical thought 7
The control device, at the timing of performing irrigation,
An irrigation system described in technical idea 5, in which stagnant water in the water supply path is drained without being released to the plants when either the temperature of the water supply path falls below a pre-freeze threshold set at a temperature higher than the freezing temperature of water, or the temperature of the water supply path exceeds the drainage threshold.

Technical thought 8
Before determining whether the soil temperature exceeds the temperature of the water supply path or whether the temperature of the water supply path exceeds a drainage threshold, the control device:
An irrigation system described in any one of Technical Ideas 1 to 7, which forcibly prohibits irrigation when the soil moisture content exceeds a growth inhibition threshold, which is a value that is likely to inhibit the growth of the plant.

Technical thought 9
An irrigation system described in any one of technical ideas 1 to 8, wherein the temperature of the water supply path is the water temperature of the supply water present in the water supply path.

Technical thought 10
An irrigation system described in any one of Technical Ideas 1 to 8, wherein the temperature of the water supply path is the temperature of the piping that forms the water supply path.

Technical thought 11
An irrigation system according to any one of Technical Ideas 1 to 10, wherein the soil temperature detected by the soil temperature sensor is the temperature of the soil in the field.

Technical thought 12
An irrigation system according to any one of Technical Ideas 1 to 10, wherein the ground temperature detected by the ground temperature sensor is the temperature of a natural grass field.

Technical thought 13
a processing unit (334) that determines whether or not to perform irrigation using the temperature of a water supply path through which irrigation water to be released to plants is supplied and the soil temperature;
When it comes to timing of irrigation,
outputting a signal prohibiting irrigation when the processing unit determines that the soil temperature exceeds the temperature of the water supply path and that the temperature of the water supply path is below an irrigation suppression threshold value;
a signal output unit (332) that outputs a signal prohibiting irrigation when the processing unit determines that the soil temperature does not exceed the temperature of the water supply path, and outputs a signal to perform irrigation when the processing unit determines that the soil temperature does not exceed the temperature of the water supply path, or when the processing unit determines that the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold;
A control device comprising:

Technical thought 14
a processing unit (334) that determines whether or not to perform irrigation using the temperature of a water supply path through which irrigation water to be discharged to plants is supplied;
When it comes to timing of irrigation,
When the processing unit determines that the temperature of the water supply path exceeds a drainage threshold, a signal is output to drain the stagnant water in the water supply path without releasing it to the plant, and then a signal is output to perform irrigation.
a signal output unit (332) that outputs a signal to perform irrigation including stagnant water when the processing unit determines that the temperature of the water supply path is lower than the drainage threshold;
A control device comprising:

20... Field, 160... Water temperature sensor (temperature sensor), 200... Control device, 312... Soil temperature sensor, 332... Signal output unit, 334... Processing unit

Claims (9)

a water supply channel through which irrigation water is supplied for release to the plants;
a temperature sensor (160) for detecting the temperature of the water supply path;
A soil temperature sensor (312) for detecting soil temperature;
a control device (200) that controls the amount of irrigation water using the soil temperature detected by the soil temperature sensor and the temperature detected by the temperature sensor;
Equipped with
The control device, at the timing of performing irrigation,
When the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is lower than an irrigation suppression threshold, the amount of irrigation water is controlled to be reduced;
An irrigation system that controls the amount of irrigation water to be increased when the soil temperature does not exceed the temperature of the water supply path, or when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold, compared to when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below the irrigation suppression threshold . a water supply channel through which irrigation water is supplied for release to the plants;
a temperature sensor (160) for detecting the temperature of the water supply path;
A soil temperature sensor (312) for detecting soil temperature;
a control device (200) that controls the amount of irrigation water using the soil temperature detected by the soil temperature sensor and the temperature detected by the temperature sensor;
Equipped with
The control device, at the timing of performing irrigation,
prohibiting irrigation when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below an irrigation suppression threshold;
An irrigation system that performs irrigation when the soil temperature does not exceed the temperature of the water supply path, or when the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold . Before determining whether the soil temperature exceeds the temperature of the water supply path, the control device:
3. The irrigation system according to claim 1 , wherein irrigation is forcibly prohibited when the soil moisture content exceeds a growth inhibition threshold value that is a value at which there is a high possibility that plant growth will be inhibited. The irrigation system according to claim 1 or 2 , wherein the temperature of the water supply path is the temperature of the supply water present in the water supply path. The irrigation system according to claim 1 or 2 , wherein the temperature of the water supply path is the temperature of a pipe forming the water supply path. 3. The irrigation system according to claim 1 , wherein the soil temperature detected by the soil temperature sensor is the temperature of the soil in the field. 3. The irrigation system according to claim 1 , wherein the soil temperature detected by the soil temperature sensor is the temperature of a natural grass field. a processing unit (334) that determines whether or not to perform irrigation using the temperature of a water supply path through which irrigation water to be released to plants is supplied and the soil temperature;
When it comes to timing of irrigation,
outputting a signal prohibiting irrigation when the processing unit determines that the soil temperature exceeds the temperature of the water supply path and that the temperature of the water supply path is below an irrigation suppression threshold value;
a signal output unit (332) that outputs a signal to perform irrigation when the processing unit determines that the soil temperature does not exceed the temperature of the water supply path, or when the processing unit determines that the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold;
A control device comprising: a processing unit (334) that determines whether or not to perform irrigation using the temperature of a water supply path through which irrigation water to be released to plants is supplied and the soil temperature;
When it comes to timing of irrigation,
outputting a signal to reduce the amount of irrigation water when the processing unit determines that the soil temperature exceeds the temperature of the water supply path and that the temperature of the water supply path is below an irrigation suppression threshold;
a signal output unit (332) that outputs a signal to increase the amount of irrigation water compared to when it is determined that the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path is below the irrigation suppression threshold value, when the processing unit determines that the soil temperature does not exceed the temperature of the water supply path, or when it determines that the soil temperature exceeds the temperature of the water supply path and the temperature of the water supply path exceeds the irrigation suppression threshold value;
A control device comprising: