JP2013055895A - Nutrient solution supply apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nutrient solution supply apparatus which gives no obstacle to the growth of vegetation, and can prevent the occurrence of damage even when a sensor for measuring an ingredient amount of nutrient solution breaks down.SOLUTION: The nutrient solution supply apparatus 10 includes: a first pH sensor 32 and a second pH sensor 33 that measure the pH of the nutrient solution to vegetation in a dilution mixing vessel 14; a nutrient solution supply controller 41 that supplies the acid nutrient solution from an acid tank 13 to the dilution mixing vessel 14 based on the first pH sensor 32; and a monitoring controller that determines whether the absolute value of the difference between measured values from the first and second pH sensors 32 and 33 is within a prescribed range, and outputs a supply stop signal to direct to stop the supply of the acid nutrient solution to a supply pump when the absolute value is out of the prescribed range.

Description

  The present invention relates to a nutrient solution supply apparatus for supplying a nutrient solution to a plant.

  In hydroponics, the supply of nutrient solution along with the supply of water is important for plant growth. If there is a mistake in the amount of nutrient solution supplied to the plant, there is a risk that the plant will wither rather than promote the growth of the plant. For example, Patent Documents 1 to 3 propose techniques that can accurately supply the nutrient solution.

  In Patent Document 1, a branch pipe through which a part of the nutrient solution flows is provided in the nutrient solution supply pipe, and the detection value by the detection unit is detected by detecting the component amount of the nutrient solution flowing in the branch tube by the detection unit. A nutrient solution supply device for a plant cultivation factory that can accurately indicate the concentration of components supplied to the cultivation floor is described.

  Further, in Patent Document 2, when measuring the conductivity, pH value, and various ion concentrations of a nutrient solution using a sensor unit and performing control so as to match the target range according to the priority order, for example, an item of lower priority order, for example, ion During the concentration control, there is described a hydroponic cultivation apparatus that stops the control of the ion concentration and preferentially controls the conductivity when the upper item, for example, the conductivity deviates from the target range.

  In Patent Document 3, the conductivity, pH value, and various ion concentrations in a nutrient solution used for plant cultivation are measured by a sensor unit, and when each value is outside a predetermined range, adjustment of the components of the nutrient solution is performed. A hydroponic cultivation apparatus provided with conductivity control means, pH control means, and ion concentration control means is described.

JP-A-4-316434 JP-A-6-209661 Japanese Patent Laid-Open No. 7-227163

  However, in these conventional nutrient solution supply devices, the component amount of the nutrient solution is measured by a sensor and the component amount of the nutrient solution is adjusted based on the measured value, but it is considered until the sensor breaks down. It has not been. For example, because the sensor failed and the measurement value that was within the suitability range was output despite the component amount being outside the suitability range, the nutrient solution component amount was excessive or within the suitability range. The measured value that is out of the proper range is output, so the nutrient solution amount is insufficient. When the amount of nutrient solution is excessive, the plant may grow poorly or wither, causing serious damage.

  Accordingly, an object of the present invention is to provide a nutrient solution supply device that can prevent the occurrence of damage without hindering the growth of a plant even if a sensor that measures the amount of a nutrient solution fails. .

The nutrient solution supply apparatus of the present invention determines whether or not the ranges indicated by the measured values from the plurality of sensors and the plurality of independent sensors that measure the component amount of the nutrient solution to the plant are within a predetermined range, And a controller that outputs a supply stop signal to the supply pump for instructing to stop the supply of the nutrient solution when it is outside the predetermined range.
According to the nutrient solution supply apparatus of the present invention, since a plurality of sensors for measuring the component amount of the nutrient solution are provided independently of each other, the measured value or suitability range in which one sensor fails and falls within the proper range Even if the measurement value that is outside is output, if the other sensor is operating normally, the difference from the measurement value obtained by the other sensor becomes large, so that the range indicated by the measurement value is widened. Therefore, the controller can determine whether or not the sensor has failed by determining whether or not the measured value from each sensor is within a predetermined range, so the supply of nutrient solution by the supply pump is stopped. By doing so, it is possible to prevent the plant growth from being hindered.

  It is desirable that the controller outputs the supply stop signal only to a supply pump that supplies the acidic nutrient solution to the plant. If too much acidic nutrient solution is supplied to the plant, it will directly affect the growth of the plant. Therefore, the controller outputs a supply stop signal only to the supply pump that supplies the acidic nutrient solution to the plant, thereby continuing the supply of other nutrient solutions and promoting the growth of the plant, while hindering the growth of the plant. The excessive supply of the acidic nutrient solution to be applied can be stopped.

The plurality of sensors includes a first sensor and a second sensor, and the controller starts and stops the supply of nutrient solution to the supply pump based on the measurement value from the first sensor, and the supply amount. The controller of the nutrient solution supply control that performs adjustment of the feed pump, and stops the operation of the supply pump when the difference between the measured value from the first sensor and the measured value from the second sensor is out of a predetermined range It is desirable to be composed of a monitoring controller.
By configuring the controller from a nutrient solution supply control controller and a monitoring controller, if the nutrient solution supply control controller is installed as a conventional nutrient solution supply device, the failure of the first and second sensors is detected. By adding a monitoring controller, the fault tolerance of the nutrient solution supply device can be easily improved.

  According to the present invention, since the failure of the sensor can be detected and the supply of the nutrient solution by the supply pump can be stopped, it is possible to prevent the growth of the plant from being hindered and to prevent the occurrence of damage. can do.

It is a figure which shows the structure of the nutrient solution supply apparatus which concerns on embodiment of this invention. It is a flowchart for demonstrating operation | movement of the controller for nutrient solution supply control of the nutrient solution supply apparatus shown in FIG. 1, (A) is a figure for demonstrating the control which adjusts a liquid fertilizer density | concentration, (B) is a pH adjuster. It is a figure for demonstrating the control which adjusts the density | concentration of this. It is a flowchart for demonstrating operation | movement of the monitoring controller of the nutrient solution supply apparatus shown in FIG.

  A nutrient solution supply apparatus according to an embodiment of the present invention will be described with reference to the drawings. The nutrient solution supply apparatus 10 shown in FIG. 1 is used in hydroponics, and adjusts the fertilizer and pH adjuster which are nutrient solutions, and supplies them to the cultivation tank which is not shown in which a plant is grown. In the present embodiment, a baby leaf will be described as an example of a plant grown by hydroponics.

  The nutrient solution supply apparatus 10 adjusts the pH because the nutrient solution circulating in the first fertilizer tank 11 and the second fertilizer tank 12 in which two types of fertilizers are respectively stored and the cultivation tank is likely to be alkaline. An acid tank 13 in which an acidic nutrient solution that is a pH adjusting agent is stored, and a dilution mixing tank 14 for mixing and diluting them are provided.

  The first fertilizer tank 11 is provided with a first fertilizer supply pump 21 that pumps up the liquid fertilizer from the first fertilizer tank 11 and supplies the liquid fertilizer to the dilution mixing tank 14. The second fertilizer tank 12 is provided with a second fertilizer supply pump 22 that pumps up the liquid fertilizer from the second fertilizer tank 12 and supplies the liquid fertilizer to the dilution mixing tank 14. The acid tank 13 is provided with a pH adjusting agent supply pump 23 that pumps up the acidic nutrient solution in the acid tank 13 and supplies it to the dilution mixing tank 14.

  The dilution mixing tank 14 is provided with a stirring device 15 for stirring the supplied liquid manure and the acidic nutrient solution. Moreover, in the dilution mixing tank 14, an EC (Electric Conductivity) sensor 31 for measuring the conductivity indicating the concentration of the liquid fertilizer component, and a first pH sensor 32 for measuring the pH which is the amount of the nutrient solution component. And the second pH sensor 33 are provided independently of each other.

  The EC sensor 31 and the first pH sensor 32 are connected to a nutrient solution supply control controller 41. The second pH sensor 33 is connected to the monitoring controller 42. The first pH sensor 32 is also connected to the monitoring controller 42 via the communication line S <b> 1 via the nutrient solution supply controller 41.

  The nutrient solution supply control controller 41 starts, stops, and supplies the first fertilizer supply pump 21 and the second fertilizer supply pump 22 based on the measured value indicating the conductivity of the nutrient solution from the EC sensor 31. And adjusting the start / stop / supply amount of the pH adjusting agent supply pump 23 via the communication line S2 based on the measured value indicating the pH value of the nutrient solution from the first pH sensor 32. .

  The monitoring controller 42 makes a determination based on the pH values measured by the first pH sensor 32 and the second pH sensor 33, and indicates supply stop indicating stop of the pH adjusting agent supply pump 23 via the communication line S3. A signal is notified to the nutrient solution supply control controller 41, or a supply stop signal is directly notified to the pH adjusting agent supply pump 23 via the communication line S4. The monitoring controller 42 is provided with an alarm rotating lamp 43 for notifying an operator when an abnormality is detected. In the present embodiment, the measured value measured by the first pH sensor 32 is notified from the nutrient solution supply controller 41 to the monitoring controller 42 via the communication line S1.

  The operation and use state of the nutrient solution supply apparatus according to the embodiment of the present invention configured as described above will be described with reference to the drawings. First, the control method of the nutrient solution supply controller 41 will be described based on the flowchart shown in FIG.

  A method for controlling the liquid fertilizer concentration of the nutrient solution supply controller 41 will be described with reference to the flowchart shown in FIG. The nutrient solution supply control controller 41 reads the measured value indicating the liquid fertilizer concentration from the EC sensor 31 (step S10). The nutrient solution supply control controller 41 determines the concentration of the liquid fertilizer based on the measured value (step S20). When the concentration of liquid fertilizer in the dilution and mixing tank 14 is high, the nutrient solution supply control controller 41 instructs the first and second fertilizer supply pumps 21 and 22 to stop (step S30). Further, water is supplied to the dilution mixing tank 14 for dilution. If the concentration of liquid fertilizer is low, the nutrient solution supply control controller 41 instructs the first and second fertilizer supply pumps 21 and 22 to specify a predetermined supply amount, and instructs to increase the concentration (step S40). .

  Next, a method for controlling the concentration of the pH adjusting agent of the nutrient solution supply control controller 41 will be described with reference to the flowchart shown in FIG. The nutrient solution supply controller 41 reads the measured value indicating the pH value of the nutrient solution from the first pH sensor 32 (step S50). The nutrient solution supply controller 41 determines the pH value of the nutrient solution based on the measured value (step S60). When the pH value of the dilution mixing tank 14 is alkaline or neutral, the nutrient solution supply controller 41 adjusts the supply amount of the acidic nutrient solution according to the pH value to the pH adjuster supply pump 23. An instruction is given (step S70). When the concentration of liquid fertilizer is higher than a predetermined range where the concentration becomes acidic, the nutrient solution supply control controller 41 instructs the pH adjusting agent supply pump 23 to stop (step S80). For example, the supply amount of the acidic nutrient solution is gradually reduced to the nutrient solution supply control controller 41 when the pH value becomes 6.5, and the supply of the acidic nutrient solution is stopped when the pH value becomes 6. You can set it.

  As described above, the nutrient solution supply control controller 41 performs the adjustment of the liquid fertilizer concentration shown in FIG. 2 (A) and the adjustment of the concentration of the pH adjusting agent shown in FIG. 2 (B) in parallel. Thus, the nutrient solution supply controller 41 performs the control shown in FIG. 2 (A) in addition to operating the control shown in FIG. 2 (A) and the control shown in FIG. 2 (B) in parallel. It is also possible to perform the control shown in FIG. This is because supplying the acidic nutrient solution to increase the acidic concentration by the control shown in FIG. 2B affects the liquid fertilizer concentration, and the liquid fertilizer concentration may fluctuate. Therefore, in such a case, the nutrient solution supply control controller is configured so that the pH value is adjusted by the control shown in FIG. 2A after the control shown in FIG. This can be avoided by setting 41.

Here, as the nutrient solution supply device, there is no monitoring controller 42, only the nutrient solution supply control controller 41 is installed, and therefore, the conventional nutrient solution supply device also includes only the first pH sensor 32. The case of will be described.
For example, the supply amount of the acidic nutrient solution is gradually decreased in the nutrient solution supply controller 41 when the pH value becomes 6.5, and the pH adjusting agent supply pump 23 when the pH value becomes 6. Is set to stop. Then, suppose that the first pH sensor 32 fails and 8 is measured as a measured value even though the pH value of the nutrient solution is actually 6.
In this case, the nutrient solution supply control controller 41 operates so as to decrease by 2 as the pH value. Accordingly, the nutrient solution supply control controller 41 starts the pH adjusting agent supply pump 23 and continues to supply the acidic nutrient solution from the acid tank 13 to the dilution mixing tank 14.
As a result, the actual pH value becomes 4 even if the pH value of the dilution mixing tank 13 is 6 in the failed first pH sensor 32. Further, depending on the failure mode of the first pH sensor 32, it may be lower than 4.
If the pH value of the nutrient solution is 4, the baby leaf will die out in a short time and cannot be shipped as a product.

  As described above, the nutrient solution supply apparatus 10 according to the present embodiment includes not only the nutrient solution supply controller 41 but also the monitoring controller 42 that monitors based on the pH value measured from the second pH sensor 33. ing. The operation of the monitoring controller 42 will be described with reference to FIG.

  As shown in FIG. 3, the monitoring controller 42 first reads the measured value from the first pH sensor 32 as the first pH value (step S110). Next, the monitoring controller 42 reads the measured value from the second pH sensor 33 as the second pH value (step S120). Next, the monitoring controller 42 calculates the absolute value of the difference between the first pH value and the second pH value (step S130). Next, the monitoring controller 42 determines whether the first pH value and the second pH value are within a predetermined range by determining whether the result calculated in step S130 is equal to or less than a predetermined value. Determination is made (step S140).

  When the calculated result is less than the predetermined value, the monitoring controller 42 determines that the first pH sensor 32 and the second pH sensor 33 are operating normally, and ends one monitoring operation. . When the calculated result is equal to or greater than the predetermined value, the monitoring controller 42 notifies the nutrient solution supply control controller 41 to stop the pH adjusting agent supply pump 23 and also supplies the pH adjusting agent supply pump 23 to the stop. Also directly stops (step S150). The notification from the monitoring controller 42 may be directly output to the pH adjusting agent supply pump 23. However, for the sake of safety, the nutrient solution supply control controller 41 can be notified by notifying the nutrient solution supply control controller 41. Since the stop is output to the pH adjusting agent supply pump 23, the pH adjusting agent supply pump 23 can be surely stopped.

  For example, if the measurement error of the sensors installed as the first pH sensor 32 and the second pH sensor 33 is 0.2 in pH value, there is a gap between the first pH sensor 32 and the second pH sensor 33. The maximum error of 0.4 occurs. In consideration of this error, the pH adjusting agent supply pump 23 can be stopped when the absolute value of the difference between the first pH value and the second pH value is out of the range of 1 or more.

  For example, it is assumed that the nutrient solution supply control controller 41 is set to stop the pH adjusting agent supply pump 23 when the pH value reaches 6. If the first pH sensor 32 fails and indicates a neutral or alkaline value greater than 7, and the normally operating second pH sensor 33 indicates 6, the first pH sensor 32 One or more differences occur between the sensor 32 and the second pH sensor 33. Therefore, even if either the first pH sensor 32 or the second pH sensor 33 fails, the pH value of the nutrient solution in the dilution mixing tank 14 is 6 by stopping the pH adjusting agent supply pump 23. Since it can be made not to become below, it can prevent that the growth of a plant is disturbed. Therefore, the nutrient solution supply apparatus 10 can prevent the occurrence of damage.

  In addition, even if the first pH sensor 32 and the second pH sensor 33 indicate alkalinity and neutrality, respectively, when the difference in pH value is 1 or more, the measurement greatly exceeds the measurement error range. Therefore, when the monitoring controller 42 detects an abnormality, it can be detected that one of the first pH sensor 32 and the second pH sensor 33 has failed. . In some cases, it can be detected that both the first pH sensor 32 and the second pH sensor 33 are out of order.

  When the monitoring controller 42 notifies the pH adjusting agent supply pump 23 of the stop, the monitoring controller 42 turns on the alarm rotating lamp 43 serving as a notification means (step S160). Also, a sound notification is given by a buzzer or the like. The operator can know the abnormality by the alarm from the alarm rotating lamp 43.

  In the present embodiment, the controller is configured by the nutrient solution supply controller 41 and the monitoring controller 42 separately, but may be a single controller. However, if the nutrient solution supply controller 41 is installed as a conventional nutrient solution supply device, it is easy to add a monitoring controller 42 that detects the failure of the first and second pH sensors 32 and 33. Since the fault tolerance of the nutrient solution supply apparatus 10 can be improved, it is desirable that the controller is composed of a nutrient solution supply control controller 41 and a monitoring controller 42.

  In addition, the monitoring controller has a function of stopping the pH adjusting agent supply pump 23 when any of the measured values from the first pH sensor 32 and the second pH sensor 33 indicates an acidity that is a predetermined value or less. 42 can also be provided. By doing so, not only the nutrient solution supply control controller 41 but also the monitoring controller 42 can monitor the pH value. Therefore, the nutrient solution supply control controller 41 breaks down and the measured value from the first pH sensor 32 is measured. Even when the nutrient solution supply control controller 41 is trying to supply the acidic nutrient solution, the monitoring controller 42 can stop the supply.

  In addition, the measured value from the first pH sensor 32 is notified from the nutrient solution supply controller 41 to the monitoring controller 42 via the communication line S1, but the first pH sensor 32 notifies the monitoring controller 42. You may make it notify directly to.

  In the present embodiment, two units, the first pH sensor 32 and the second pH sensor 33, are provided for measuring the pH as a plurality of independent sensors for measuring the amount of the nutrient solution to the plant. However, it can be set to 3 or more according to the measurement location. When three or more sensors are provided, it can be determined that all the sensors are normal if the range indicated by all the measured values is within a predetermined range. For example, if the range indicated by all measured values is within 1 in terms of pH value, it can be determined as normal. Further, it can be determined that a sensor whose measured value is out of the predetermined range is broken.

  Moreover, it is good also as a sensor which measures the component amount of nutrient other than pH to provide multiple sensors. For example, a plurality of sensors for measuring the fertilizer concentration can be provided and monitored.

  When hydroponically cultivating a baby leaf, the nutrient solution in the dilution / mixing tank 14 that circulates between the cultivation tanks is likely to be alkaline, so that only the acidic nutrient solution stored in the acid tank 13 is provided as a pH adjuster. Therefore, the controller controls only the supply of the acidic nutrient solution, and stops supplying the acidic nutrient solution when the sensor is abnormal. For example, in the case of a plant that supplies an acidic nutrient solution and an alkaline nutrient solution, even if an excessive amount of the alkaline nutrient solution is supplied to the plant, the controller does not immediately affect the growth of the plant. By stopping only the supply pump that supplies the acidic nutrient solution, it is not necessary to provide an extra sensor to be monitored, and it is possible to stop the excessive supply of the acidic nutrient solution that hinders the growth of the plant.

  Furthermore, in this embodiment, two sensors (first pH sensor 32, second pH sensor 33) are installed in the dilution mixing tank 14, but before feeding the nutrient solution to the cultivation tank, A nutrient solution storage tank (not shown) for deaeration from a nutrient solution containing bubbles by stirring with the agitator 15 or before feeding the nutrient solution to the dilution mixing vessel 14 from the cultivation tank. You may make it provide a sensor in the storage tank (not shown) of the nutrient solution for calming. Moreover, a sensor is installed independently in the dilution mixing tank 14 and the cultivation tank one by one, or a plurality of sensors are set as a set, and a plurality of sets of sensors are independently installed in the dilution mixing tank 14 and the cultivation tank. It can also be installed. And the absolute value of the difference of the measured value from the sensor installed in the dilution mixing tank 14 and the cultivation tank is calculated, and when this result turns into a difference more than predetermined, it determines with any sensor having failed. You may make it do.

  The nutrient solution supply apparatus of the present invention is a hydroponic method such as thin film hydroponic (NFT), submerged hydroponic (DFT), spray plowing, solid medium plowing, capillary hydroponic, gravel plowing, etc. Suitable for cultivation and soil cultivation methods.

DESCRIPTION OF SYMBOLS 10 Nutrient solution supply device 11 1st fertilizer tank 12 2nd fertilizer tank 13 Acid tank 14 Dilution mixing tank 15 Stirring device 21 1st fertilizer supply pump 22 2nd fertilizer supply pump 23 For pH adjusters Supply pump 31 EC sensor 32 First pH sensor 33 Second pH sensor 41 Nutrient solution supply controller 42 Monitoring controller 43 Alarm rotating light S1, S2, S3, S4 Communication line

Claims (3)

A plurality of independent sensors for measuring the amount of nutrient solution in the plant,
A controller that determines whether or not the range indicated by the measured values from the plurality of sensors is within a predetermined range, and outputs a supply stop signal to the supply pump instructing to stop supplying the nutrient solution when it is outside the predetermined range And a nutrient solution supply device.   The nutrient solution supply apparatus according to claim 1, wherein the controller outputs the supply stop signal only to a supply pump that supplies the acidic nutrient solution to the plant. The plurality of sensors includes a first sensor and a second sensor,
The controller includes a nutrient solution supply control controller for starting and stopping the supply of nutrient solution to the supply pump based on a measurement value from the first sensor, and adjusting a supply amount, and a measurement from the first sensor. The nutrient solution supply device according to claim 1, further comprising a monitoring controller that stops the operation of the supply pump when a difference between a value and a measured value from the second sensor is out of a predetermined range. .

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