Saturation deficit control device

Abstract

To provide an inexpensive humidity deficit controlling device that can perform precise humidity deficit control such that appropriate humidification is performed to an objective space to appropriately perform photosynthesis of plant.SOLUTION: A seasonal pattern is determined from solar irradiation and temperature (Fig. 4a), and a threshold value is determined on the basis of a difference between a current humidity deficit and a preset humidity deficit and a determined seasonal pattern (Fig. 4b, S2). A mist 7 is operated only by a shortest ON time to perform humidification only when an output value exceeds the threshold value (S3, S4). In calculation of the threshold value, boundary values X, Y dividing a range of a difference between the current humidity deficit and the preset humidity deficit (Fig. 4b) can be arbitrary preset depending on an environment or a season. After humidification, in the case where a newly acquired output value exceeds the threshold value (S6), a humidification time is added according to the output value (S7-S9). In the case where a command of additional 1 cycle is issued, the shortest OFF time stops with only one time of addition (S8-S11).SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a saturation deficit control device that controls a humidifier to set the saturation deficit of a target space to a desired value, and more particularly to a saturation deficit control device that can control a humidifier in an optimal manner corresponding to the season and actual environmental conditions. [Background technology]

[0002] Patent Document 1 below discloses an invention related to a saturation deficit control device that generates multiple types of mists with different water contents using a single spray device and controls the saturation deficit in a greenhouse so that it quickly reaches a target value. This saturation deficit control device is installed in a cultivation greenhouse and includes a spray device 2, a measuring device 3, and a control device 4. The spray device 2 includes a sprayer body 21, a liquid supply pipe 22, a flow rate adjustment valve 23, a compressor 24, and a gas supply pipe 25. The sprayer body 21 includes a substantially bullet-shaped main body 210, a gas introduction port 211 formed on the side of the main body 210, a venturi portion 212 which is a fine hole penetrating the main body 210 in the longitudinal direction, a spray portion 213 provided at the tip of the main body 210, and a liquid introduction port 214 provided at the base end of the main body 210. Note that the reference numerals assigned to the components in the above description are those used in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-216885 Summary of the Invention [Problem to be solved by the invention]

[0004] The saturation deficit control device disclosed in Patent Document 1 is expensive due to the use of multiple nozzles. Furthermore, the sprayer used cannot be digitally turned on and off; instead, the control method increases the amount of liquid sent to the sprayer when the saturation deficit is high and decreases the amount of liquid sent to the sprayer when the saturation deficit is low. This makes it difficult to precisely control the saturation deficit, such as precisely matching the actual saturation deficit to the target saturation deficit. However, because the range of saturation deficit suitable for photosynthesis is narrow, precise control of the humidification amount is required. In particular, excessive humidification can cause the surfaces of leaves and fruits to become wet, which can lead to disease. Conversely, low humidification and prolonged dryness or sudden dryness can cause water stress, causing plants to close their stomata as a defensive response to water stress. Stomatal closure prevents photosynthesis and affects plant growth. Therefore, precise control of the humidification amount is important for plant growth.

[0005] The present invention has been made in consideration of the problems in the conventional technology described above, and aims to provide a saturation deficit control device that is an inexpensive control device that can be retrofitted to a spray device or the like already installed in a target space, and that is capable of performing precise saturation deficit control so as to appropriately humidify the target space and allow plants to properly photosynthesize. [Means for solving the problem]

[0006] The saturation deficit control device according to claim 1 comprises: A vapor deficit control device that controls a current vapor deficit in a target space by operating a humidifier in accordance with an output value generated so that the current vapor deficit in the target space becomes a set vapor deficit, a storage unit that stores the set vapor pressure deficit and a plurality of seasonal patterns; a vapor deficit calculation unit that calculates the current vapor deficit using the temperature and humidity of the target space; The system has a basic control mode in which a threshold is calculated based on the temperature and solar radiation of the target space, the deviation between the current vapor pressure deficit and the set vapor pressure deficit, and the seasonal pattern, and the humidifier is operated for the shortest ON time only when the output value exceeds the threshold. In addition, the system is characterized by having a control unit that can change the range of the deviation corresponding to the multiple thresholds set for each seasonal pattern as needed when calculating the threshold.

[0007] The saturation deficit control device according to claim 2 is the saturation deficit control device according to claim 1, The deviation range is divided by boundary values, and the deviation range can be changed by changing the boundary values.

[0008] The saturation deficit control device according to claim 3 is the saturation deficit control device according to claim 1, A plurality of threshold values ​​are set for each seasonal pattern by an output upper limit value, which is an upper limit of the output value that is arbitrarily set, and a multiplying factor by which the output upper limit value is multiplied.

[0009] The saturation deficit control device according to claim 4 is the saturation deficit control device according to claim 1, The control unit calculates the output value by PID calculation based on the data in the storage unit and environmental data, and is characterized in that it can arbitrarily adjust the proportional gain, integral time, and derivative time in the PID calculation.

[0010] The saturation deficit control device according to claim 5 is the saturation deficit control device according to any one of claims 1 to 4, After controlling the humidifier in the basic control mode, if the newly acquired output value exceeds the threshold value, the control unit continues to control the humidifier for a time period corresponding to the output value as long as it is within the control time, but when a specified command is given, the control unit performs the operation of operating the humidifier only once for a time period corresponding to the output value, and then stops the humidifier for the shortest OFF time. [Effects of the Invention]

[0011] According to the vapor deficit control device of claim 1, in basic control mode, the device calculates the current vapor deficit using the temperature and humidity of the target space, determines the corresponding seasonal pattern from the temperature and solar radiation of the target space, and determines a threshold value on which to determine whether to operate the humidifier based on the deviation between the current vapor deficit and the set vapor deficit and the determined seasonal pattern. Then, only when the output value exceeds the threshold value, the device operates the humidifier for the minimum ON time to humidify. Therefore, even when a humidifier with a minimum ON time is being controlled and the current vapor deficit is smaller than the set vapor deficit or is only slightly larger, it is possible to avoid excessive humidification of the target space by operating the humidifier for the specified time. As a result, the vapor deficit of the target space can be controlled in a desirable manner according to the appropriate seasonal pattern, allowing plants to properly perform photosynthesis in the target space. Furthermore, in calculating the threshold value, the deviation range corresponding to the multiple threshold values ​​set for each seasonal pattern can be changed as needed. This makes it possible to achieve detailed vapor saturation deficit control that suits the situation by changing the deviation range corresponding to the multiple threshold values ​​set for each seasonal pattern as needed in special situations in the target space, such as when the humidifier is operating even though the current vapor saturation deficit is lower than the set vapor saturation deficit and the space is humid, or when the space is prone to dryness and the current vapor saturation deficit rises quickly, or when there are special seasonal situations, such as when the current vapor saturation deficit tends to increase in summer or when the current vapor saturation deficit tends to decrease in winter.

[0012] According to the saturation deficit control device recited in claim 2, by appropriately changing the boundary values ​​in accordance with the actual situation as described above, two ranges of deviation corresponding to at least two threshold values ​​set for each seasonal pattern can be changed in a timely manner in accordance with the situation, thereby making it possible to reliably achieve fine-tuned saturation deficit control. The boundary values ​​may be two or more, and by appropriately changing the two boundary values, three ranges of deviation corresponding to at least three threshold values ​​set for each seasonal pattern can be changed in a timely manner in accordance with the situation, making it possible to reliably achieve even finer saturation deficit control.

[0013] According to the saturation deficit control device of claim 3, the threshold value, which is the standard for determining the duration of mist spray by the humidifier, can be freely set, and therefore the device can be used in a way that suits the user's wishes, such as by setting the threshold value appropriately low to control the humidifier to continue operating and prevent the humidifier from being stopped for too long, making it easy to use.

[0014] According to the saturation deficit control device recited in claim 4, the proportional gain can be set to an arbitrary value to adjust the output fluctuation, and the integral time and differential time can be set to arbitrary values ​​to adjust the reaction speed, thereby making it possible to perform ideal PID calculations suited to the situation.

[0015] According to the saturation deficit control device of claim 5, in the basic control mode, after controlling the humidifier using a threshold value as a judgment criterion, if the recalculated output value exceeds the threshold value, the humidifier can be controlled to operate by adding an additional humidification time according to the output value, but repeated addition of humidification time may result in excessive humidification for certain types of crops. In such a case, if a predetermined command is given to the control unit by pressing a predetermined switch before starting control or at the time when such an addition is judged to be excessive, the addition of humidification time can be completed only once and the humidifier can be stopped for at least the shortest OFF time. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is an overall configuration diagram of a saturation deficit control device according to an embodiment; [Figure 2] 1A and 1B are diagrams showing control data set in a saturation deficit control device of an embodiment, in which FIG. 1A is a diagram of table data showing the correspondence between proportional gains and dial setting values ​​in PID calculations of output values, and FIG. 1B is a diagram of table data showing the correspondence between integral and differential times and dial setting values ​​in PID calculations of output values. [Figure 3] 4 is a graph showing a control pattern of the saturation deficit determined by a set time and a set saturation deficit set in the saturation deficit control device of the embodiment. [Figure 4] 1A and 1B are diagrams showing control data set in a saturation deficit control device of an embodiment, where FIG. 1A is a diagram showing table data for determining a seasonal pattern from the relationship between temperature and solar radiation, and FIG. 1B is a diagram showing an example of table data for determining a threshold value based on the difference between the current saturation deficit and the set saturation deficit, and the seasonal pattern. [Figure 5] 4(a) and 4(b) are diagrams showing control data set in a vapor saturation deficit control device of an embodiment, in which sub-diagram (a) is a diagram of table data showing the correspondence between one boundary value X of the boundary values ​​X and Y that divide the difference between the current vapor saturation deficit and the set vapor saturation deficit into three regions in FIG. 4(b), and the dial setting value, and sub-diagram (b) is a diagram of table data showing the correspondence between the boundary value Y and the dial setting value. [Figure 6] 4A and 4B are diagrams showing control data set in a saturation deficit control device of an embodiment, in which FIG. 4A is a diagram of table data showing a period (upper output limit value) as a reference value used to calculate the threshold value in FIG. 4B and a magnification factor by which this period is multiplied, and FIG. 4B is a diagram showing another example of table data for determining a threshold value based on the difference between the current saturation deficit and the set saturation deficit and the seasonal pattern. [Figure 7] 3 is a flowchart showing a control procedure of a basic control mode in the saturation deficit control device of the embodiment. [Figure 8] 3 is a flowchart showing a control procedure in a CO2 control mode in the saturation deficit control device of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of a saturation deficit control device of the present invention will be described with reference to FIGS. First, the overall configuration of the saturation deficit control device 1 will be described. As shown in Fig. 1, this saturation deficit control device 1 includes a sensor group S that acquires environmental data of the target space, a control means C that calculates an output value using the environmental data sent from the sensor group S, preset control data, and control data that is changed or set during control, and a controlled device M such as a humidifier (abbreviated as "mist" 7) that is controlled by the output value sent from the control means C and functions directly to adjust the saturation deficit. The control means C is also configured to be able to control an external device 20 and an alarm device 21 that outputs an alarm for a specific control item.

[0018] The target space for which the saturation deficit control device 1 performs saturation deficit control is, for example, the inside of an agricultural greenhouse. The control means C of the saturation deficit control device 1 detects the environmental conditions inside the agricultural greenhouse using a sensor group S, and operates controlled equipment M such as a mister with an output value calculated based on environmental data etc. sent from the sensor group S, thereby controlling the saturation deficit inside the agricultural greenhouse and performing saturation deficit control to create a humidity environment suitable for plants.

[0019] 1, the sensor group S includes a thermo-hygrometer 2, a solar radiation sensor 3, and a CO2 monitor 4. The thermo-hygrometer 2 measures the temperature and relative humidity (also simply called "humidity") of the target space, the solar radiation sensor 3 measures the amount of solar radiation, and the CO2 monitor 4 measures the CO2 concentration, and each outputs the measurement results to the control means C.

[0020] As shown in FIG. 1, the control means C has a sequencer 5 and a relay 6. The sequencer 5 receives inputs of temperature and humidity from the thermo-hygrometer 2, the amount of solar radiation from the solar radiation sensor 3, and the CO2 concentration from the CO2 monitor 4. The structure and operation of the sequencer 5, which is a key part of the control means C, will be described in detail later. The sequencer 5 outputs an ON / OFF signal to the relay 6 according to the calculated output value. The relay 6 operates the controlled device M, external device 20, and alarm device 21, which are installed in the target space, using the ON / OFF signal, respectively.

[0021] As shown in Fig. 1, the control target devices M operated by the control means C include a mist 7, a CO2 generator 8, an external device 20, and an alarm device 21. These control target devices M are ON / OFF controlled by an ON / OFF signal sent from a relay 6 of the control means C. The mist 7 is controlled in a basic control mode, which will be described later with reference to Fig. 7, and the CO2 generator 8 is controlled in a CO2 control mode, which will be described later with reference to Fig. 8.

[0022] The external device 20 shown in FIG. 1 is a device that is operated by an ON / OFF signal output from the control means C, and includes, for example, a dehumidifying device, a curtain opening / closing device, an exhaust fan, a skylight opening / closing device, etc., installed in an agricultural greenhouse.

[0023] 1 can issue alarms such as a high temperature alarm, a low temperature alarm, a dryness alarm, a sudden rise in saturation deficit alarm, and an excessive spray alarm. These external devices 20 and alarm devices 21 are ON / OFF controlled by an ON / OFF signal sent from a relay 6 of the control means C, either in synchronization with or asynchronously with the result of saturation deficit control, which will be described later. Note that the types and contents of alarms other than those mentioned above, as well as the sudden rise in saturation deficit alarm and the excessive spray alarm that are issued based on the result of saturation deficit control, will be explained again after the explanation of saturation deficit control.

[0024] Next, the structure of the sequencer 5 of the control means C and the saturation deficit control will be described. 1, the sequencer 5 has a memory unit 10 in which data for control is set, a vapor pressure deficit calculation unit 11 that calculates the vapor pressure deficit of the target space based on environmental data from the sensor group S, a control unit 12, and a setting unit 13. The control unit 12 selects either the basic control mode or the low-pressure mist mode to execute control.

[0025] The basic control mode is a control mode in which an output value is calculated by PID calculation based on data from the memory unit 10 and environmental data from the sensor group S, and if the output value is greater than a threshold value, the mist 7 is turned on for the shortest time (30 seconds in this embodiment), and then the spray time is extended according to the output value. The low-pressure mist mode is a mode for using low-pressure water such as tap water. Details of the basic control mode and the low-pressure mist mode will be described later.

[0026] The setting unit 13 is an input means for selecting the control mode described above, setting various setting values ​​required for control, and inputting other input items directly or by selection, but it may also have a display unit that displays the input or set setting values, current and past environmental data, current and past control states, etc.

[0027] FIG. 2 is a diagram showing, in table format, control data that is set in the storage unit 10 and that can be arbitrarily selected and set by the setting unit 13. FIG. 2(a) is a diagram of table data showing the correspondence relationship between the proportional gain KP (unit: %) when the control unit 12 performs PID calculations and the dial setting value for setting the proportional gain KP. The dial setting value is initially set to 5, in which case the proportional gain KP is 100%. The dial setting value can be arbitrarily selected between 1 and 10 by the setting unit 13, thereby setting the proportional gain to any value between 25% and 400%, and adjusting output fluctuations. For example, if the current saturation deficit value is hunting, the proportional gain KP can be reduced to stabilize the unstable output, or if there is a large fluctuation, the proportional gain KP can be increased to reduce vibrations.

[0028] FIG. 2(b) is a table showing the correspondence between the integral time I (unit: ×100 ms) and the derivative time D (unit: ×10 ms) and the dial settings when the control unit 12 performs PID calculations. The dial settings are both initially set to 5, resulting in an integral time I of 1200 (120 s) and a derivative time of 3000 (30 s). The dial settings can be arbitrarily selected between 1 and 10 by the setting unit 13, allowing the integral time I to be set to any value between 4800 (480 s) and 300 (30 s), and the derivative time D to be set to any value between 12000 (1200 s) and 750 (75 s). For example, the longer the integral time I and the derivative time D, the slower the response of the PID calculation. Therefore, if you want to speed up the response of the control output to the deviation between the current saturation deficit and the set saturation deficit, it is preferable to shorten the integral time I and the derivative time D. Also, for example, if it takes a long time for the current saturation deficit to stabilize, it is preferable to increase the integral time I and the derivative time D.

[0029] In the PID calculations described above, the output value calculated by the control unit 12 is calculated in 0.1-second units. For example, an output value of 200 indicates a 20-second operation time, and this output value allows the mist 7 to be operated for 20 seconds to humidify. In this way, with this saturation deficit control device 1, output fluctuations can be adjusted by setting the proportional gain KP to an arbitrary value, while the integral time I and derivative time D can be set to arbitrary values ​​to adjust the reaction speed, thereby performing ideal PID calculations tailored to the situation and appropriately controlling the mist 7.

[0030] Details of saturation deficit control by the sequencer 5 will be described later, but in the basic control mode of this embodiment, a minimum ON time is set as the minimum operating time for operating the mist 7, taking into consideration that repeatedly turning the pump that operates the mist 7 on and off in a short period of time can affect its lifespan, and is set to 30 seconds as an example. Furthermore, after operating the mist for the minimum ON time, if certain conditions are met, the operating time of the mist 7 is extended and continues to be extended as long as the conditions are met, but if a specific command is issued or if such a command has been set in advance, the operating time of the mist 7 is extended only once, and a specific minimum OFF time is set as the time after which the mist 7 must be stopped.

[0031] The vapor deficit calculation unit 11 calculates the vapor deficit of the target space based on the temperature and humidity data sent from the thermo-hygrometer 2.

[0032] As will be explained below, various data necessary for the control unit 12 to perform appropriate saturation deficit control are set in the memory unit 10. First, in order to properly PID control the saturation deficit in the target space according to a time schedule corresponding to sunrise and sunset, an appropriate control pattern for the saturation deficit, determined by the geographical location and season of the target space, is set in the memory unit 10. Figure 3 is an example of a graph showing such a control pattern, which becomes the target of control by the control means C. The control data to be stored in the memory unit 10 to determine such a control pattern include at least the set saturation deficit and the set time.

[0033] The set saturation deficit shown on the vertical axis of the graph in FIG. 3 is the initial saturation deficit, which is the initial saturation deficit when the control unit 12 starts saturation deficit control, and the maximum saturation deficit, which is the maximum value of the saturation deficit during the saturation deficit control time. These set saturation deficits are the target values ​​for saturation deficit control by PID control. Generally, rather than leaving the saturation deficit constant, gradually increasing it makes it easier for the stomata of plants to open and promotes photosynthesis. Therefore, the initial saturation deficit should be set to an ideal saturation deficit of 3 to 6 (g / m 3 ), and the maximum saturation deficit is set to be larger than the initial saturation deficit, but it is set to a slightly dry 9 (g / m 3It is preferable to control the saturation deficit to gradually increase from the initial saturation deficit and maintain a constant value after it reaches the maximum saturation deficit.

[0034] The set times shown on the horizontal axis of the graph in Figure 3 are the control start time, which is the time when the control unit C starts saturation deficit control, the maximum time when the saturation deficit reaches its maximum, and the control end time when saturation deficit control ends. Photosynthesis occurs from sunrise to sunset, but photosynthesis is most active in the morning. Photosynthetic activity increases from morning to noon (midday). However, photosynthetic activity does not suddenly decrease after noon. Therefore, it is considered preferable to allow a margin and control the saturation deficit to increase from the morning, when photosynthesis is most active, until about two hours after noon, when solar radiation is relatively high, until the maximum saturation deficit is reached. Furthermore, by delaying the time when the saturation deficit reaches its maximum until after midday (midday), the increase in the set saturation deficit can be made more gradual. As an example of the time control of saturation deficit described above, the control start time can be set to sunrise, the maximum time can be set to about two hours after noon, and the control end time can be set to sunset. These times vary depending on the geographical location of the target space and the season, and are therefore manually set in storage unit 10 by the user before control is performed. For example, in Yamagata City, in July, the sunrise time (control start time) is between approximately 4:19 and 4:39, the noon time (time when the maximum value is reached) is between approximately 11:42 and 11:45, and the sunset time (control end time) is between approximately 19:06 and 18:50. However, even in the same Yamagata City, in November, the sunrise time (control start time) is between approximately 6:04 and 6:35, the noon time (time when the maximum value is reached) is between approximately 11:22 and 11:27, and the sunset time (control end time) is between approximately 16:40 and 16:19. Data for the set time corresponding to such a combination of geographical location and date (season) may be stored in advance in the storage unit 10, and the set time may be automatically set by the calendar function and location specification. The calendar function can be realized by providing the sequencer 5 with a calendar date management unit that can automatically update calendar date data indicating the current date and month and output the calendar date as needed. The geographical location can be specified by providing the sequencer 5 with an input unit that can input geographical location specification information by any method, such as character input on the screen or selection from a list.

[0035] Next, the memory unit 10 stores control data for determining a threshold value that serves as the basis for determining whether the control unit 12 should operate the mist 7 for the shortest ON time (30 seconds, for example, in this embodiment). This threshold value is appropriately set depending on the difference between the current vapor deficit and the set vapor deficit, and the combination of the season. Only when the output value output by the PID control unit 12 exceeds this threshold value will the control unit 12 operate the mist 7 for the shortest ON time to humidify the air. Figure 4 is a schematic table showing the control data that is set in the memory unit 10 and can be selected and set as needed by the setting unit 13.

[0036] Figure 4(a) shows data for determining seasonal patterns (1) to (5) based on the combination of solar radiation (vertical column) and temperature (horizontal column) in the target space. Seasonal patterns (1) and (2) indicate environmental conditions with low solar radiation and low temperature, which are common in winter. Seasonal patterns (4) and (5) indicate environmental conditions with high solar radiation and high temperature, which are common in summer. Seasonal pattern (3) indicates an intermediate environmental condition. Note that even in winter, if solar radiation is high, the temperature inside the greenhouse will rise, so seasonal pattern (4) may be applied. Furthermore, if the temperature is below 15°C, saturation deficit control is not performed.

[0037] Figure 4(b) shows the seasonal patterns (1) to (5) ("Pattern" in the vertical column) determined in Figure 4(a) and the deviation between the set saturation deficit and the current saturation deficit ("Difference from set saturation deficit (g / m 3 The threshold value (0 to 350) is determined by a combination of the seasonal pattern (1) and the set saturation deficit. For example, for seasonal pattern (1), the threshold value is set to a high value between 200 and 350 depending on the difference between the current saturation deficit and the set saturation deficit, preventing excessive humidification. For seasonal pattern (5), the temperature is high and the saturated water vapor pressure is high, but the actual humidity is low, so a lower value is set to encourage humidification.

[0038] The control unit 12 determines the seasonal pattern using the data shown in FIG. 4(a) that the storage unit 10 has, based on the solar radiation amount acquired from the solar radiation sensor 3 and the temperature acquired from the thermometer-hygrometer 2. Further, using the determined seasonal pattern, the current saturation difference calculated by the saturation difference calculation unit 11, the set saturation difference set in the storage unit 10, and the data shown in FIG. 4(b) set in the storage unit 10, it calculates the deviation of the current saturation difference with respect to the set saturation difference and the threshold value suitable for the seasonal pattern. Further, the control unit 12 compares the output value calculated by the PID operation with this threshold value, and outputs an ON signal to the relay 6 only when the output value exceeds the threshold value, and operates the mist 7 via the relay 6 for a specified time (shortest ON time) to perform humidification.

[0039] In FIG. 4(b), the deviation between the set saturation difference and the current saturation difference shown in the horizontal column is divided into three regions by two boundary values X and Y (X < Y), and threshold values are defined for each of the three regions of the deviation and for each of the five seasonal patterns. And in the saturation difference control device 1 of the present embodiment, as will be described below, the two boundary values X and Y can be arbitrarily set or changed during control. That is, by changing the boundary values X and Y, the ranges of the three regions separated by the boundary values X and Y (X < Y) to which threshold values are respectively assigned can be adjusted freely in width.

[0040] FIG. 5 is a diagram showing control data set in the storage unit 10. Sub-diagram (a) is a diagram of table data showing the correspondence between the boundary value X (in the right column in the figure) and the dial setting value (the “dial” in the left column in the figure), and sub-diagram (b) is a diagram of table data showing the correspondence between the boundary value Y (in the right column in the figure) and the dial setting value (the “dial” in the left column in the figure). These table data are stored in the storage unit 10.

[0041] As shown in FIG. 5(a), the dial setting value corresponding to the boundary value X is, at the initial value, 6, and in that case the boundary value X (deviation) is -1. The dial setting value can be arbitrarily selected between 1 and 10 by the setting unit 13, and thereby the boundary value X can be set to a deviation of an arbitrary value between 0 and -2.

[0042] As shown in FIG. 5(b), the initial dial setting value corresponding to boundary value Y is 5, in which case boundary value Y (deviation) is 1. The dial setting value can be arbitrarily selected between 1 and 10 by setting unit 13, thereby allowing boundary value Y to be set to any deviation value between 0.5 and 2.5.

[0043] According to the saturation deficit control device 1 of the embodiment, by appropriately changing the two boundary values ​​X and Y in accordance with the actual situation of the target space, the three ranges of deviation corresponding to at least three threshold values ​​set for each seasonal pattern can be appropriately set or appropriately changed in a timely manner in accordance with the situation described below, and therefore, detailed saturation deficit control can be reliably achieved.

[0044] For example, if the mist 7 is operating even though the current saturation deficit is lower than the set saturation deficit and the room is humid, excessive humidification can be prevented by reducing the dial setting and increasing the boundary value X, thereby setting a stricter, larger threshold. Also, if the room is prone to dryness and the current saturation deficit rises quickly, appropriate humidification can be promoted by increasing the dial setting and decreasing the boundary value X, thereby setting a lenient, smaller threshold.

[0045] In addition, in special seasonal situations, such as in the summer when the current saturation deficit is likely to be large and the air is dry, the dial setting value can be reduced to decrease boundary value Y and set a lenient, small threshold value to promote moderate humidification.In addition, in the winter when the current saturation deficit is likely to be small and the humidity is high, the dial setting value can be increased to increase boundary value Y and set a stricter, large threshold value to prevent excessive humidification.

[0046] In the embodiment, the deviation range is divided into three by the two boundary values ​​X and Y, and a threshold value is set for each division, but the number of boundary values ​​is not limited to two. If there is one boundary value, the calculation of saturation deficit control becomes simpler, and if there are three or more boundary values, more precise saturation deficit control becomes possible.

[0047] In Fig. 4(b), the three ranges of deviation between the set vapor deficit and the current vapor deficit shown in the horizontal column and the 15 threshold values ​​determined according to the five seasonal patterns shown in the vertical column are set as specific numerical values ​​ranging from 0 to 350, but this is merely an example, and as will be explained below, the specific values ​​can be set or changed arbitrarily while maintaining the ratio between the threshold values. The control data required for this purpose is stored in the storage unit 10 as table data as shown in Fig. 6.

[0048] FIG. 6(a) is a diagram of table data showing the period (output upper limit) as a reference value used to calculate the threshold value and the multiplier by which it is multiplied. This control data includes 15 control data cases divided into three threshold classifications ("Stop," "Strong," and "Low") corresponding to the three classifications based on the deviation of saturation deficit and five seasonal patterns. Of these control data, the basis for calculating each threshold is the period, which is the "Strong" value of seasonal pattern (1), i.e., the value obtained by multiplying the upper limit of the output value (output upper limit) in the PID calculation by 10. The other 14 control data are shown as multiplication factors for the "Strong" value of seasonal pattern (1).

[0049] FIG. 6(b) is a diagram showing another example of table data in which threshold values ​​are determined based on three threshold categories corresponding to the difference between the current vapor pressure deficit and the set vapor pressure deficit, and on seasonal patterns. The threshold values ​​shown here differ from the example shown in FIG. 4(b). The control data shown in FIG. 6(b) is threshold data calculated when the output upper limit value in FIG. 6(a) is set to 10 seconds. The control data shown in FIG. 4(b) is threshold data calculated when the output upper limit value in FIG. 6(a) is set to 30 seconds. The output upper limit value can be arbitrarily set by the user in setting unit 13.

[0050] Therefore, the user can freely set the threshold value, which is the standard for determining the spray time of the mist 7, and can use it in a way that suits the user's wishes, such as by setting the threshold value appropriately low to control the operation of the mist 7 to continue and prevent the stop time from becoming too long, making it easy to use.

[0051] Next, the saturation deficit control in the basic control mode in the saturation deficit control device 1 described above will be described with reference to the flow chart of FIG. 7 and FIG. As the first stage of control, "shortest ON time" control is performed in steps S2 to S4 of Figure 7. When control is started with the mist 7 in the OFF state (S1), the control unit 12 periodically (for example, once every 10 seconds) calculates an output value and a threshold value through PID calculation (S2). If the output value from the PID calculation exceeds the threshold value (S3, YES), the control means C sends an ON signal to the mist 7, driving it for the shortest ON time of 30 seconds to humidify the target space (S4). If the output value from the PID calculation does not exceed the threshold value (S3, NO), the same control is repeated.

[0052] According to the "shortest ON time" control of steps S2 to S4 in FIG. 7, because there is a threshold limit, even if the current vapor pressure deficit is smaller than the set vapor pressure deficit or is only slightly larger, it is possible to prevent the humidifier 7 from operating for the specified 30 seconds, which would result in excessive humidification of the target space.

[0053] As the second stage of control, "add-on time" control is performed in steps S5 to S9 of FIG. 7. If the mist 7 is driven for the minimum ON time under "minimum ON time" control using a threshold value by the control unit 12 (S4), the output value is calculated again using PID calculation at that time, and the threshold value is calculated (S5). If the output value exceeds the threshold value (S6, YES), the control unit C sends an ON signal to the mist 7 for a time corresponding to the calculated output value, humidifying the target space (S7). Next, it is determined whether the "add-on one-cycle switch" that issues a command to the control unit 12 to end the "add-on time" control after one cycle is ON (S8). If the switch is not pressed (S8, NO), if the control time is within (S9, YES), the process returns to S5 and repeats the "add-on time" control. If the control time is not within (S9, NO), the control ends (S10).

[0054] If the "additional one cycle switch" that issues a command to the control unit 12 to end the "additional time" control after only one time is ON (S8, YES), the humidification time addition is ended after only one time, and the humidifier is always stopped for at least the shortest OFF time (S11). If it is within the control time (S12, YES), the process returns to S2 to repeat the "shortest ON time" control, and if it is not within the control time (S12, NO), the control ends (S10).

[0055] According to this saturation deficit control device 1, after controlling the mist 7 based on a threshold value in basic control mode, if the recalculated output value exceeds the threshold value, the humidifier can be controlled to operate by adding an additional humidification time according to that output value. However, repeated addition of the humidification time can cause certain types of crops, such as spinach, to become over-humidified because the leaves tend to get wet easily, which can be undesirable. If such a situation is anticipated, the setting unit 13 can be operated to give a predetermined command to the control unit 12 before starting control, or at the point in time when such a situation is encountered and determined to be present, thereby ending the addition of the humidification time just once and stopping the mist 7 for at least the shortest OFF time.

[0056] Next, a low-pressure mist mode will be described as another control mode that can be selected in saturation deficit control by this saturation deficit control device 1. The basic control mode and the low-pressure mist mode described above can be switched alternatively by the user's selection in the setting unit 13, and either one can be selected.

[0057] The basic control mode described above is based on the use of a high-pressure mist sprayer 7, which sprays fine mist particles by applying high pressure to water. This makes it difficult for crops to become wet, making it relatively easy to manage crops and control humidity. However, because high-pressure mist sprayers 7 are expensive, many users prefer to use low-pressure mist sprayers that use low-pressure water such as tap water or well water. The low-pressure mist mode, which uses this low-pressure mist, is characterized by its control to limit the mist spray time, since the mist produced by low-pressure water has large particles that easily wet crop leaves.

[0058] In low-pressure mist mode, the control unit 12 uses PID calculations to calculate an output value indicating the stop time of the mist 7 (low-pressure mist device), and compares this with a threshold to operate the mist 7. The control data stored in the memory unit 10 is generally the same as in basic control mode. When control begins, the mist 7 is stopped for the shortest OFF time, and then a threshold is calculated based on the temperature and solar radiation in the target space, the deviation between the current vapor pressure deficit and the set vapor pressure deficit, and the seasonal pattern. If the output value exceeds the threshold, the mist 7 is operated for a fixed ON time, but if the output value does not exceed the threshold, the mist 7 continues to be stopped for a predetermined OFF time following the shortest OFF time.

[0059] In the low-pressure mist mode, the mist 7 is controlled so that the spray time is limited. This allows the use of low-cost low-pressure mist that uses low-pressure water from a water pipe or the like as a humidifier for saturation deficit control in agricultural greenhouses, and also limits the spray time of drizzle-like mist, which has large particle sizes and therefore easily wets crops.

[0060] In the saturation deficit control in the basic control mode and low-pressure mist mode described above, if an abnormal value occurs in a control item, the alarm device 21 issues an alarm to alert the user. The types of alarms and their contents are as follows: The high temperature alarm is issued when the temperature measured by the thermo-hygrometer 2 is higher than the set value. The low temperature alarm is issued when the temperature measured by the thermo-hygrometer 2 is lower than the set value. The high humidity alarm is issued when the relative humidity measured by the thermo-hygrometer 2 is higher than the set value, or when the vapor deficit calculated by the vapor deficit calculation unit 11 is lower than the set value. The dryness alarm is triggered when the relative humidity is lower than the set value or the saturation deficit is higher than the set value. The high CO2 alarm is issued when the CO2 concentration measured by the CO2 monitor 4 is higher than a set value. The low CO2 alarm is issued when the CO2 concentration measured by the CO2 monitor 4 is lower than a set value. The sudden rise in saturation deficit alarm is triggered when the change in saturation deficit over a five-minute period is greater than the set value. The temperature sensor abnormality alarm and humidity sensor abnormality alarm are issued when the thermo-hygrometer 2 is abnormal. The solar radiation sensor abnormality alarm is issued when the solar radiation sensor 3 is abnormal. The CO2 sensor abnormality alarm is issued when the CO2 monitor 4 is abnormal. The excessive spray alarm is issued when the spray time is longer than the set value, and the saturation deficit control is forcibly stopped. In addition, these alarm output functions are provided with an alarm retention function, so that once an alarm is output, the alarm output continues even if the alarm disappears on the display screen of the setting unit 13, but this can be canceled by pressing the alarm reset button on the display screen of the setting unit 13.

[0061] Of the alarm outputs from the alarm device 21, the alarm for a sudden rise in saturation deficit is set based on knowledge of plant physiology. That is, according to this knowledge, in order to maintain the opening of the stomata in the leaves to promote the photosynthesis of crops, it is necessary that the saturation deficit does not change suddenly and that it is within an appropriate range (generally 3 to 6 g / L). 3 ) and once the saturation deficit has suddenly changed or deviated from the appropriate range, it is not easy to reopen the saturation deficit. Therefore, in this alarm device 21, the 5-minute saturation deficit change amount, which indicates the amount of change in saturation deficit in 5 minutes, is set to a predetermined reference value (for example, 5 gm 3 ) is exceeded, an alarm is issued. The reference value can be changed arbitrarily by the setting unit 13.

[0062] Furthermore, among the alarm outputs from the alarm device 21 described above, the excessive spray alarm can effectively deal with cases where the sensor group S has failed or where the mist 7 continues to be sprayed beyond the limit due to a programming error in the control means C.

[0063] Next, the CO2 control by the saturation deficit control device 1 of this embodiment will be described with reference to the flow chart of FIG. 8 and FIG. As shown in Fig. 8, when the control start time arrives at which crop photosynthesis begins and saturation deficit control in the basic control mode begins, CO2 control also begins (S21). First, the control means C acquires solar radiation data from the solar radiation sensor 3, and the control unit 12 determines whether the measured solar radiation is greater than the control stop solar radiation, which is the lower limit for photosynthesis (S22). If the solar radiation is greater than the reference value (S22, YES), the control unit 12 determines whether the current vapor deficit calculated by the vapor deficit calculation unit 11 is within a range suitable for photosynthesis, i.e., between the lower limit and the upper limit (S23). If the current vapor deficit is between the lower limit and the upper limit (S23, YES), the control unit 12 acquires the CO2 concentration measurement result from the CO2 monitor 4 and determines whether the CO2 concentration is less than the lower limit (S24). If the CO2 concentration is below the lower limit (S24, YES), the sequencer 5 of the control means C outputs an ON / OFF signal to the relay 6, and the relay 6 operates the CO2 generator 8 intermittently according to the ON / OFF signal (S25). If the CO2 concentration acquired from the CO2 monitor 4 is not above the upper limit (S26, NO), the control unit 12 continues the intermittent operation of the CO2 generator 8 (S25). However, if the CO2 concentration is above the upper limit (S26, YES), and if it is within the control time (S27, YES), the control returns to S22 and continues to control the CO2 concentration. If it is not within the control time (S27, NO), the control of the CO2 concentration ends at the control end time when photosynthesis stops (S28).

[0064] If the measured amount of solar radiation is smaller than the reference value (S22, NO), if the current vapor deficit calculated by the vapor deficit calculation unit 11 is not within the range of the lower limit value or more and the upper limit value or less (S23, NO), or if the measured CO2 concentration is not equal to or less than the lower limit value (S24, NO), the control unit 12 will not perform intermittent operation of the CO2 generator 8 until the conditions for proper photosynthesis are satisfied, and will return to S22 to continue CO2 concentration control as long as it is within the control time (S29, YES), but if it is not within the control time (S29, NO), it will end CO2 concentration control at the control end time when photosynthesis will no longer be performed (S28).

[0065] The CO2 control by the saturation deficit control device 1 of this embodiment described above is performed in parallel with saturation deficit control in the basic control mode or the low-pressure mist mode. This makes it possible to prevent the CO2 concentration from falling below the lower limit while the saturation deficit is being properly controlled, thereby achieving the effect of further promoting photosynthesis.

[0066] Furthermore, the saturation deficit control device 1 of this embodiment can be constructed by replacing only the control means with the control means C of this embodiment in an agricultural greenhouse already equipped with a group of sensors S, such as a thermo-hygrometer 2, and controlled devices M, such as a mist vent 7. This means that it can be retrofitted to equipment already installed in the agricultural greenhouse, making it inexpensive. In addition, in such existing equipment, the minimum ON time of the mist vent 7 is set to, for example, 30 seconds. When control by the existing conventional control means begins and the output value is calculated, even if the calculated value is 1, spraying will continue for 30 seconds. However, with the saturation deficit control device 1 of this embodiment, a threshold limit is set in the control unit 12 of the control means C, preventing such unnecessary activation of the mist vent 7 and allowing for the necessary spray time to be added, thereby enabling the above-described appropriate saturation deficit control. [Explanation of symbols]

[0067] 1...Saturation deficit control device 2…Thermo-hygrometer 3...Solar radiation sensor 5...Sequencer 7...Humidifier (mist) 8...CO2 generator 10...Storage section 11...Saturation difference calculation section 12...Control unit 13...Settings section 20...External device 21…Alarm device S: Sensor group M: Controlled equipment C...Control means KP: Proportional gain I…integration time D...differential time

Claims

1. A vapor deficit control device that controls a current vapor deficit in a target space by operating a humidifier in accordance with an output value generated so that the current vapor deficit in the target space becomes a set vapor deficit, a storage unit that stores the set vapor pressure deficit and a plurality of seasonal patterns; a vapor pressure deficit calculation unit that calculates the current vapor pressure deficit using the temperature and humidity of the target space; A vapor deficit control device having a basic control mode in which a threshold value is calculated based on the temperature and solar radiation of a target space, the deviation between the current vapor deficit and the set vapor deficit, and the seasonal pattern, and in which the humidifier is operated for the shortest ON time only when the output value exceeds the threshold value, and further comprising a control unit that can, in calculating the threshold value, change the range of the deviation corresponding to the plurality of threshold values ​​set for each of the seasonal patterns as necessary.

2. 2. A saturation deficit control device according to claim 1, wherein the range of the deviation is divided by a boundary value, and the range of the deviation is changed by changing the boundary value.

3. 2. The saturation deficit control device according to claim 1, wherein a plurality of threshold values ​​are set for each of the seasonal patterns by using an output upper limit value that is an upper limit of the output value that is arbitrarily set and a multiplying factor by which the output upper limit value is multiplied.

4. 2. The saturation deficit control device according to claim 1, wherein the control unit calculates the output value by PID calculation based on the data in the storage unit and the environmental data, and can arbitrarily adjust a proportional gain, an integral time, and a derivative time in the PID calculation.

5. 5. The saturation deficit control device according to claim 1, wherein, after controlling the humidifier in the basic control mode, if the newly acquired output value exceeds the threshold value, the control unit continues control of operating the humidifier for a time period corresponding to the output value as long as the control time is within the control time, but when a predetermined command is given, the control unit performs an operation of operating the humidifier only once for the time period corresponding to the output value and then stops the humidifier for a shortest OFF time.

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