KR102287219B1 - Apparatus for measuring weight of water content of plants growing medium and Method for calculating moisture fluxes of plants growing medium - Google Patents

Abstract

The present invention relates to a medium moisture content measuring apparatus and a method for calculating the water inflow and outflow of the medium, which have excellent assembly properties while reducing manufacturing cost, and can calculate the amount of water inflow and outflow of the medium only by the measured weight of the medium, and a seating surface on which the medium is seated And a medium frame including a bottom surface that is lower than the seating surface, and a guide part for guiding the nutrient solution discharged from the medium and falling in one direction, a nutrient solution movably provided in the medium frame and collecting and discharging the nutrient solution guided by the guide part It provides a medium moisture content measuring device comprising a discharge unit and a medium weight measuring unit for measuring the weight of the medium.

Description

Apparatus for measuring weight of water content of plants growing medium and Method for calculating moisture fluxes of plants growing medium

The present invention relates to an apparatus for measuring medium moisture content and a method for calculating the moisture inflow and outflow of a medium, and more particularly, to a medium moisture content capable of calculating the moisture inflow and outflow of the medium only with the measured weight of the medium alone, with excellent assembly properties while reducing manufacturing costs. It relates to a measuring device and a method for calculating the amount of water in and out of the medium.

Nutrient solution Irrigation is a nutrient solution containing essential elements required for plant growth according to a set composition ratio after planting or seeding plants in a medium without using land and planting them in various ways. means a plant cultivation method that supplies for plant growth. Unlike the method of planting and cultivating plants in the land, cultivation of plants through nutrient solution irrigation can precisely and uniformly control the environment of the soil in which the plants are planted, so plants are actively used for mass production. In addition, the cultivation method of plants through nutrient solution irrigation is more widely used because it is possible to establish a cultivation area for plants through nutrient solution irrigation even in a space where plant cultivation is difficult due to securing sufficient land or land pollution.

Cultivation of plants through nutrient solution irrigation is greatly affected by the appropriate water content in the medium. In general, when the moisture content in the medium is high, crops grow vegetatively, and when the moisture content is low, reproductive growth occurs. However, an excessively high moisture content in the medium adversely affects the roots of crops, and an excessively low moisture content improves root growth, but under strong light conditions, the crops can easily wither and cause harm, so proper management is important.

In order to properly manage the appropriate water content in the medium, a device for measuring the water content of the medium was devised and used through Korean Patent No. 10-1326596. However, as a side wall is formed on the edge of the tray on which the medium is placed, drainage accumulates, so accurate water content measurement is not performed. In order to form the side wall, a process called welding is additionally required. There is a problem that is required.

Furthermore, since the size of the accessories is large, it interferes with the working radius in the greenhouse, and the height of the sample medium to be weighed is higher than other mediums, so the amount of liquid supplied may be different due to the difference in the head (pressure) of the dripper, and also Since there are many types of accessories, there is a problem in that a large cost is incurred in the manufacturing process, and inaccurate measured values may appear due to the penetration of foreign substances such as leaves and petals into the fastening area.

In addition, in the case of the top tray for mounting the medium, structural welding is required for water collection, and water accumulates at the edge of the corner or in the area in contact with the medium, resulting in inaccurate measurement values and accumulation of foreign substances such as green algae or due to a humid environment. There is a problem that can be the starting point of damage by pests.

On the other hand, in the cultivation of plants through nutrient solution irrigation, changes in moisture in the medium during the day also have a great influence on the growth of plants. Crop growth can be controlled by using the difference in water content during the day. For example, plants are grown through nutrient solution irrigation while the daily moisture content is maintained at 6-8%, 8-10% when reproductive growth is induced, and 4-6% when vegetative growth is induced. However, it is not a simple task to measure the moisture in the medium and make appropriate changes.

In order to measure the moisture in the medium and give appropriate changes, a nutrient solution cultivation management device was devised and commercialized through Korean Patent No. 10-1843883. Through this nutrient solution cultivation management device, the slab weight and nutrient solution showing a certain pattern according to time-dependent changes Based on the amount of supply and drainage, it is now possible to automatically manage the nutrient solution in case of an abnormality in the management of the nutrient solution. However, in order to measure the weight of the slab, the amount of liquid supplied, the amount of drainage, etc., a liquid supply detection unit, a drainage detection unit, and a weight detection unit including a sensor are separately provided, which increases the manufacturing cost. There was a problem that was not easy.

An object of the present invention is to provide an apparatus for measuring the moisture content of a medium that can be easily maintained and accurately obtained with a simple structure, and can be manufactured inexpensively, through one embodiment.

In addition, the present invention, through an embodiment, is to provide a method for calculating the amount of water inflow and outflow of the medium capable of calculating the amount of inflow and outflow of the medium without installing a sensor of the island.

The present invention, in order to solve the above-described problem, a seating surface on which the medium is seated; and a guide part including a bottom surface having a height lower than the seating surface and guiding the nutrient solution discharged from the medium and falling in one direction; a nutrient solution discharging unit movably provided in the medium frame and configured to collect and discharge the nutrient solution guided from the guide unit; and a medium weight measurement unit for measuring the weight of the medium.

The nutrient solution discharge unit may be provided with a coupling plate having a coupling slit formed thereon to be coupled to the guide unit, and the guide unit may be provided with a plurality of coupling holes through which a plurality of coupling parts passing through the coupling slit are fastened.

The genital nutrient solution discharge unit is a lower plate; a pair of guide plates formed by bending one side of the lower plate; And one side of the pair of guide plates may be bent to be coupled to the guide portion, respectively.

The nutrient solution discharge unit may be spaced apart from each other by the pair of guide plates to form a space through which the nutrient solution is discharged.

The medium weight measuring unit includes: an upper panel provided with an upper support portion protruding upward so that the medium frame can be seated; a load cell having an upper protrusion coupled to the upper panel at one end and a lower protrusion at the other end opposite to the one end; and a lower support coupled to the lower protrusion and protruding downward.

The upper support part is spaced apart along the longitudinal direction of the delivery frame to form a plurality of parts, and the delivery frame may be rotated by a predetermined angle around a part of the upper support part due to the concentration of the weight.

In addition, the present invention is a method for calculating the amount of water inflow and outflow of the medium through the measured change rate derived by measuring the change rate of the weight of the medium in which the plants are planted, in the case of the water supply section in which the nutrient solution is supplied to the medium, the measured change rate and the previously A liquid supply section calculating step of calculating the amount of inflow and outflow of the medium in comparison with the set first reference change rate; and calculating the amount of water in and out of the medium by comparing the measured change rate and a preset second reference change rate in the case of the non-supply section in which the nutrient solution supply to the medium is stopped; The above-mentioned problem is solved by providing a method.

In the step of calculating the liquid supply interval, if the measured change rate is similar to the first reference change rate, it is determined that the nutrient solution is supplied to the medium but not discharged from the medium to calculate the increased production and the amount of liquid supplied.

In the liquid supply section calculating step, if the measured change rate is not similar to the first reference change rate, it is determined as the section in which the nutrient solution is discharged from the medium while being supplied to the medium to calculate the increased production, the amount of liquid supplied, and the amount of drainage.

The first reference change rate may be calculated for a predetermined period during which drainage is not performed after the nutrient solution supply is first started after maintaining a state in which there is no nutrient solution supply for a preset period.

In the non-supply section calculation step, if the measured change rate is similar to the second reference change rate, it is determined as the section in which the nutrient solution is discharged from the medium to calculate the transpiration amount and the drainage amount.

In the non-liquid supply section calculating step, if the measured change rate is not similar to the second reference change rate, it is determined that the nutrient solution is not discharged from the medium, and the transpiration amount can be calculated.

The calculating of the non-payment section includes a first non-supply section calculation step performed before the calculation step of the non-payment section and a second non-payment section calculation step performed after the calculation step of the non-payment section, and the calculation of the second non-payment section The second reference change rate of the step may be calculated in a state in which the supply and drainage are stopped for a predetermined period prior to the end point of the first non-payment section calculation step.

The non-payment section calculation step and the non-payment section calculation step are alternately performed, and the second reference change rate may be calculated for each non-payment section calculation step.

The second reference change rate of the second non-supply section calculation step may be used for calculating the increase in production in the liquid supply section calculation step performed after the first non-repayment section calculation step.

As described above, the present invention has the following effects according to the embodiment.

First, according to an embodiment of the present invention, since the medium moisture content measuring device can be manufactured with a simple structure, maintenance is easy, it is possible to obtain an accurate measurement value, and it provides the effect of being able to manufacture it inexpensively.

Second, according to an embodiment of the present invention, it provides the effect of calculating the amount of water in and out of the medium without installing a separate sensor.

Third, according to an embodiment of the present invention, it is not a method of indirectly inferring the transpiration amount of a plant by measuring the temperature of the leaf and substituting it into the transpiration model empirical formula, but provides an effect that can be quantitatively measured in a medium-based crop.

Fourth, according to an embodiment of the present invention, it is possible to establish a precise irrigation strategy through quantitative moisture movement monitoring in plants and to maximize production through optimal cultivation conditions.

1 is a perspective view showing a medium moisture content measuring apparatus according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view illustrating the apparatus for measuring water content of the medium shown in FIG. 1 .
3 is a partial perspective view showing the nutrient solution discharge unit shown in FIG.
4 is a view for explaining the processing of the nutrient solution discharge unit shown in FIG.
5 is a perspective view showing the medium weight measuring unit shown in FIG.
6 is a view for explaining the coupling relationship between the medium weight measuring unit and the medium frame shown in FIG. 1 .
FIG. 7 is a graph showing changes over time in the amount of water in and out of the medium measured by the medium weight measurement unit shown in FIG. 1 .
FIG. 8 is an enlarged view of a portion indicated by P in FIG. 7 .

It should be understood that the embodiments described below are illustratively shown to aid understanding of the invention, and the present invention may be implemented with various modifications different from the embodiments described herein. However, in the description of the present invention, if it is determined that a detailed description of a related known function or component may unnecessarily obscure the gist of the present invention, the detailed description and detailed illustration thereof will be omitted. In addition, the accompanying drawings are not drawn to scale in order to help understanding of the invention, but dimensions of some components may be exaggerated.

The first and second terms used in the present application may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

In addition, the terms used in the present application are only used to describe specific embodiments, and are not intended to limit the scope of rights. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this application, terms such as "comprises", "consists of" or "consisting It should be understood that this does not preclude the possibility of addition or existence of further other features or numbers, steps, operations, components, parts, or combinations thereof.

1 is a perspective view showing a medium moisture content measuring device 1 according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view showing the medium moisture content measuring device 1 shown in FIG. 1 . 1 and 2 , the apparatus 1 for measuring water content of a medium according to an embodiment of the present invention includes a medium frame 100 , a nutrient solution discharge unit 300 and a medium weight measurement unit 500 .

The medium frame 100 is provided on at least one side of the frame body 110 and the frame body 110 formed so that the medium is seated and includes a guide unit 130 for guiding the nutrient solution discharged from the medium in one direction.

The frame body 110 is made of a seating surface so that the medium can be seated on the upper surface, and is formed in a flat plate shape.

The guide unit 130 forms a long flow path in which a space is formed so that the nutrient solution discharged from the medium seated on the seating surface can fall and be temporarily accommodated. The guide part 130 is provided on the lower side of the frame body 110 . Specifically, the guide part 130 is formed to extend upward from one end of the bottom surface 131 of the lower height than the seating surface, the bottom surface 131, and the inner wall 133 coupled to the frame body 110, the bottom surface ( It includes an outer wall 135 that is formed extending upwardly from the other end of the 131).

The outer wall 135 is provided with a plurality of coupling holes 137 so that the nutrient solution discharge part 300 to be described later is movably coupled.

On the other hand, the discharge frame 100 may be integrally formed with the frame body 110 and the guide unit 130 . Specifically, the inner wall 133 , the bottom surface 131 , and the outer wall 135 of the guide unit 130 may be formed by bending the edge of one plate constituting the delivery frame 100 . In this case, there is no need to couple the guide part 130 to the frame body 110 through welding, etc., and the process is simple, thereby reducing costs.

Since the medium frame 100 has no side wall surrounding the seating surface, the nutrient solution discharged from the medium does not accumulate on one side and falls directly to the guide unit 130 . Since the medium frame 100 is inclined downward in one direction by the medium weight measuring unit 500 to be described later, the fallen nutrient solution is guided in one direction through the guide unit 130 .

Hereinafter, the nutrient solution discharging unit 300 will be described with reference to FIGS. 3 and 4 . 3 is a partial perspective view showing the nutrient solution discharging unit 300 shown in FIG. 1 , and FIG. 4 is a view for explaining the processing of the nutrient solution discharging unit 300 shown in FIG. 1 .

3 and 4 , the nutrient solution discharging unit 300 is movably provided in the medium frame 100 , and collects and discharges the nutrient solution guided by the guide unit 130 .

The nutrient solution discharge unit 300 has a coupling slit 351 formed on one side, and is movably coupled to the guide unit 130 through a fastening member such as a bolt passing through the coupling slit 351 and the coupling hole 137. . In this case, the coupling slit 351 is formed to extend along the moving direction of the nutrient solution discharge unit 300 , and the separation distance between the coupling holes 137 is shorter than the length of the coupling slit 351 .

The nutrient solution discharge unit 300 has a receiving space 371 for temporarily accommodating the nutrient solution therein, and a lower plate 310 forming a bottom, a guide plate extending upward from the tip of the lower plate 310 . (330) and the guide plate 330 includes a coupling plate 350 that is formed extending from the side end toward the rear end of the lower plate 310.

The lower plate 310 is disposed in the lower portion of the delivery frame 100 is disposed to be inclined downward in a direction away from the delivery frame (100). Accordingly, after the nutrient solution guided from the guide unit 130 falls and is collected in the nutrient solution discharge unit 300 , it moves along the lower plate 310 to the lower side of the lower plate 310 and is discharged.

A discharge space for discharging is formed on one side of the guide plate 330 so that the nutrient solution moved along the lower plate 310 is discharged. In addition, the guide plate 330 forms a predetermined angle with respect to the discharge space. Therefore, the guide plate 330 can prevent the nutrient solution from pooling in the receiving space 371 .

Meanwhile, the guide plates 330 may be spaced apart from each other to form a pair. In this case, the discharge space is a space formed between the pair of guide plates 330 .

The coupling plate 350 is provided at the other end of the guide plate 330 , that is, at a portion farthest away from the discharge space. The coupling plate 350 is provided as a pair, and a coupling slit 351 extending long for movably coupling with the outer wall 135 of the guide part 130 is provided. The coupling structure with the coupling hole 137 is as described above, and the coupling plate 350 and the outer wall 135 of the guide part 130 may be in surface contact.

Meanwhile, the lower plate 310, the guide plate 330, and the coupling plate 350 of the nutrient solution discharge unit 300 may be integrally formed. For example, one plate constituting the lower plate 310 is laser cut into a predetermined shape, the tip is bent upward to form the guide plate 330 , and one side of the guide plate 330 is bent to combine the plate 350 . can form. In this case, there is no need for welding, etc., so the process is simple and cost is reduced.

Hereinafter, the medium weight measuring unit 500 will be described with reference to FIGS. 5 and 6 . 5 is a perspective view showing the medium weight measuring unit 500 shown in FIG. 1 , and FIG. 6 is a view for explaining the coupling relationship between the medium weight measuring unit 500 and the medium frame 100 shown in FIG. 1 .

5 and 6 , the medium weight measuring unit 500 includes an upper panel 510 , a load cell 530 , and a lower panel 550 .

The upper panel 510 is formed so that the delivery frame 100 can be seated. Specifically, the upper panel 510 is formed in a plate shape, and the edge is bent downward to secure strength to form the upper flange 513 .

A plurality of upper support parts 511 for supporting a load are provided on the upper panel 510 . The upper support part 511 is adjustable in height so that an object supported may be inclined. The above-described delivery frame 100 is also seated on the upper support part 511 and is inclined by the upper support part 511 .

The load cell 530 is a sensor (sensor) capable of measuring a physical quantity such as force or load, and when a force is applied, an electrical signal is generated as much as the force, an indicator, a microcontroller, a computer device, etc. If the electrical signal is reinterpreted with this method, the weight can be displayed in units such as kg and g. Since the detailed principle is known technology, detailed description thereof will be omitted.

The load cell 530 is provided with upper protrusions 531 protruding upwardly on the upper side, respectively, on the upper surfaces of both ends, and lower protrusions 533 protruding downwardly on the lower side are respectively provided on the lower surfaces of both ends.

An upper coupling piece 561 is provided on any one of the upper protrusions 531 , and a lower coupling piece 562 is provided on the lower protrusion 533 at the other end opposite to one end provided with the upper protrusion 531 . do.

The upper coupling piece 561 is disposed between the upper panel 510 and the load cell 530 to couple both through a fastening member such as a bolt (BT). The lower coupling piece 562 is disposed between the load cell 530 and the lower panel 550 to couple both through a fastening member such as a bolt BT.

The lower panel 550 is formed to seat the load cell 530 . Specifically, the lower panel 550 is formed in a plate shape, and the edge is bent upward to secure strength to form the lower flange 553 .

A plurality of lower support parts 551 for supporting the lower flange 553 are provided on the lower surface of the lower panel 550 . The lower support part 551 is adjustable in height and each height can be adjusted so that the medium weight measuring part 500 is horizontal.

Meanwhile, referring to FIG. 6 , when the plate PL on which an object such as the delivery frame 100 is mounted is seated on the upper support 511 and the weight of the object is measured, the object moves to one side of the plate PL. As a result, a load may be applied to one side as indicated by the arrow. In this case, a moment such as a rotational force is applied to the upper support part 511 located on one side where the object moves, so that the load cell 530 is permanently installed beyond the maximum allowable load range of the portion to which the upper coupling piece 561 is coupled or the load cell 530 . may damage it.

In order to solve this problem, in the medium moisture content measuring apparatus 1 according to an embodiment of the present invention, the upper support part 511 only supports the load of the medium frame 100 and is not coupled to the medium frame 100 . Therefore, when the load deflection phenomenon occurs, it may occur because the discharge frame 100 rotates around the upper support part 511 .

Hereinafter, a method for calculating the amount of water in and out of the medium according to an embodiment of the present invention will be described with reference to FIGS. 7 and 8 . 7 is a graph showing the change over time of the amount of water in and out of the medium measured by the medium weight measuring unit 500 shown in FIG. 1 , and FIG. 8 is an enlarged view of the portion indicated by P in FIG. 7 .

7 and 8, the method for calculating the amount of water inflow and outflow of the medium according to an embodiment of the present invention calculates the amount of water inflow and outflow of the medium through the measurement change rate derived by measuring the change rate of the weight of the medium in which the plants are planted, Do not use a sensor or the like to measure a value other than the weight value.

In general, in crops such as tomatoes, paprika, cucumber, etc. that are grown in a medium-based nutrient solution, the growth of the crops varies greatly depending on the irrigation strategy. Since the growth of crops is greatly affected by the irrigation method in which the nutrient solution is frequently applied little by little and the irrigation method that is given a lot at a time and at a long time interval, the irrigation strategy can be established by quantifying and monitoring the amount of nutrient solution supply, drainage, and plant transpiration.

By measuring the weight of the medium, not only the water content of the medium, but also the pattern of water absorption (transpiration) by crops can be quantitatively identified. Here, the medium moisture content is an index indicating the amount of water in the medium. Volume-based moisture content, which is the ratio of the volume of water to the volume of the medium, is sometimes used.

By using the transpiration value of the crop calculated by measuring the weight of the medium, it can be helped to set the amount of one-time watering, watering interval, irrigation start and end time, etc. to be input into the nutrient system. An appropriate irrigation method can be suggested according to the growth state.

Conventional water content measuring devices have a large volume in the cultivation space, which affects the working radius and accurate measurement, and the manufacturing cost is high because there are many accessories and fastening parts. In addition, in the case of the upper tray used in the conventional water content measuring device, water is stagnant, so the measurement is inaccurate, and it may cause accumulation of foreign substances or pests. Furthermore, in order to measure the amount of supply, drainage, and transpiration, it is necessary to install a separate sensor, which increases production cost and maintenance items, and there is a problem in that inaccurate measurement is made due to the occurrence of algae and fertilizer crystallization.

Accordingly, the method for calculating the amount of inflow and outflow of the medium according to an embodiment of the present invention uses the above-described medium moisture content measuring device 1, and measures the weight of the medium and its change (instantaneous slope) to calculate the amount of water in and out of the medium. The amount of water in and out of the medium is the amount of supply, drainage, and transpiration. The calculation of the amount of moisture in and out of the medium is performed by the control unit 700 receiving a signal from the input/output terminal of the load cell 530 .

In the medium moisture content measuring device 1, the medium is surrounded by a member that prevents moisture from evaporating from the medium into the air, such as vinyl, in order to accurately calculate the transpiration amount measurement.

Referring to FIG. 7 , on the graph, the left y-axis represents the weight (kg) of the medium, the right y-axis represents the stomatal transpiration amount (kg) of the crop, and the x-axis represents the flow of 24 hours a day. pay The left and right edges of the x-axis represent midnight.

The transpiration of crops occurs (performs) 24 hours a day, and as shown in FIG. 7 , the transpiration accumulation line (TR) slopes upward from midnight to midnight of the next day toward the right. The transpiration of crops is actively performed during the daytime and is performed slowly at nighttime, and even in the graph of FIG. 7 , the slope of the night time is smaller than the slope of the daytime.

The water supply for supplying the nutrient solution to the medium is not performed during the night time, but is performed multiple times at a predetermined interval during the day time. When the nutrient solution exceeds the maximum water content of the medium due to the supply solution, drainage is performed in which the nutrient solution is discharged from the medium.

As shown in FIG. 7 , the medium weight line (WE) representing the weight of the medium gradually decreases from midnight to the morning, and jumps upward when the liquid supply is performed after the morning. In this case, the water supply amount can be adjusted to such an extent that the medium that has dried during the night time absorbs all of the water and does not discharge it.

At this time, the medium weight line WE is used as a first reference change rate SUref, which will be described later. The first reference change rate (SUref) refers to a weight change rate of a medium in which water supply is performed but drainage is not performed from the medium.

Meanwhile, the amount of liquid supplied when the above-described medium weight line WE jumps may be calculated using the first reference change rate SUref.

After that, the water supply is performed several times at predetermined time intervals. Accordingly, the medium weight line WE shows a sawtooth waveform. In the evening, the feeding is stopped, and the medium weight line (WE) is formed to be inclined downward in the right direction.

The amount of water in and out of the medium at night time corresponds to the amount of transpiration. This transpiration amount can be calculated using the slope of the measured medium weight line. The slope of the medium weight line can be expressed as an instantaneous slope at each point. Also, the instantaneous slope can be expressed as an average slope in a small section through linear regression. For example, the control unit 700 may receive a signal from the input/output terminal of the load cell 530 , calculate an average slope of the transpiration amount during the night time, and then calculate the transpiration amount of the night time using the corresponding time. Here, the section of the average slope may be set arbitrarily, and is not limited to a specific section.

The amount of water inflow and outflow of the medium during the day includes the amount of supply, drainage, and transpiration. Except for the supply section (S10) and the drainage section (S30) during the daytime, the amount of water in and out of the medium in the remaining sections is only the transpiration amount, so it can be calculated by calculating the amount of water in and out of the medium at night time.

During the daytime, the liquid supply section (S10) and the drain section (S30) correspond to the sawtooth waveform of FIG. 7 , and a method of calculating the amount of water in and out of the medium in this section will be described with reference to FIG. 8 .

Referring to FIG. 8 , the water supply is started from the first time point (ta), the drainage of the liquid supply is performed from the second time point (tb), and from the third time point (tc), the water supply is stopped and only drainage is performed, From time 4 (td), neither feeding nor drainage is performed. The section before the first time point (ta) is a section in which neither supply nor drainage is performed.

In this case, the drainage section S30 to which the nutrient solution is supplied and the drainage section S30 where the nutrient solution is discharged overlap each other to form an overlap section OL, and the increase section S50 in which the crop production is performed is as described above. It is the whole section together.

Hereinafter, the method for calculating the amount of water in and out of the medium will be sequentially described by dividing the region formed by the graph of FIG. 8 into regions A to D and regions A′.

Areas A and A' are sections in which only transpiration is performed. Area B is an area where water supply and transpiration are performed. Area C is an area where water supply, drainage and transpiration are made. Area D is an area where drainage and transpiration are made.

The medium weight line (WE) has a higher slope in area A' than in area A, for example, as the altitude of the sun increases and the transpiration action of crops becomes more active. Afterwards, for example, as the altitude of the sun decreases and the transpiration action of crops slows down, the gradient of the medium weight line (WE) in the A' area is lower than in the A area.

In this case, the slope calculated for a predetermined time just before the B area among the A areas is set as the second reference change rate TR1. It is assumed that the second reference rate of change TR1 is the same in the B region, C region, and D region. Accordingly, the transpiration amount of the region B, region C, and region D can be calculated using the second reference change rate TR1.

Furthermore, it is assumed that the first reference change rate SUref is also the same in the B region and the C region. Accordingly, the amount of liquid supplied in the areas B and C can be calculated through the first reference change rate SUref.

In area B, supplying liquid and increasing production are performed, and a step of comparing the medium weight line WE with the first reference change rate SUref is performed. If it is determined that the slope of the medium weight line WE is not similar to the first reference change rate SUref, it is determined that the C region is started. The similarity determination is determined by, for example, a deviation rate that deviates from the first reference change rate SUref value, and the accuracy increases as the deviation rate is set to be smaller. For example, when the size of the first reference rate of change SUref is 10 and the size of the gradient of the medium weight line WE is 11, the difference between the size of the first reference rate of change SUref and the size of the slope of the medium weight line WE is 11. If the value is 1, the churn rate may be determined to be 10%.

As an example, the amount of water in and out of the medium in area B is calculated by calculating the increase in medium weight through the medium weight line (WE) and calculating the transpiration amount through the second reference change rate (TR1). can be calculated As another example, the amount of water in and out of the medium in the B region may be calculated through the first reference change rate SUref, and the amount of transpiration may be calculated through the second reference change rate TR1.

In area C, supply, drainage, and transpiration are performed, and the step of comparing the medium weight line (WE) with the first reference change rate (SUref) is not performed, and whether the slope of the medium weight line (WE) changes to a negative number is checked. A judgment step is performed. When the slope of the medium weight line WE changes to a negative number, it is determined that the D region is started.

The amount of water in and out of the medium in area C is calculated through the first reference change rate (SUref), the amount of increase in the medium weight is calculated through the medium weight line (WE), and the transpiration amount is calculated through the second reference change rate (TR1). After that, the amount of drainage is calculated by adding the increase in the weight of the medium, the amount of liquid supplied, and the amount of transpiration.

In region D, drainage and transpiration are performed, and a step of comparing the medium weight line WE with the second reference change rate TR1 is performed. If the medium weight line WE is not similar to the second reference change rate TR1, it is determined that the A' region is started. The similarity determination is performed in the same way as the similarity determination performed in the B area.

The amount of water inflow and outflow of the medium in the D area is calculated by calculating the transpiration amount through the second reference change rate (TR1), calculating the decrease in the medium weight through the medium weight line (WE), and then subtracting the transpiration amount from the decrease in the medium weight as the drainage amount. Calculate.

In area A', as described above, only transpiration of crops is performed. Therefore, the amount of transpiration is the same as the amount of decrease in the weight of the medium. In this case, for example, when region B' of a pattern similar to region B starts after region A', the slope calculated for a predetermined time immediately before the start of region B' is set to another second reference change rate TR2. Another second reference change rate TR2 may be assumed to have the same value when regions B, 'C, and D' having similar patterns to regions B, C, and D, respectively, are started.

According to the above-described method, the amount of water in and out of the medium can be calculated using the medium weight line (WE) indicating the amount of change in the weight of the medium, and unlike the prior art, a sensor for detecting the amount of supply and drainage is not used.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto, and the technical spirit of the present invention and the following by those of ordinary skill in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

100: badge frame
110: frame body
130: guide unit
300: nutrient solution discharge unit
310: lower plate
330: guide plate
350: coupling plate
500: medium weight measurement unit
510: upper panel
530: load cell
550: lower panel

Claims (15)

a seating surface on which the medium is seated; and a guide part including a bottom surface that is lower in height than the seating surface, and provided at the edge of the seating surface to guide the nutrient solution discharged from the medium and falling in one direction;
a nutrient solution discharging unit movably provided in the medium frame and configured to collect and discharge the nutrient solution guided from the guide unit; and
Including; a medium weight measuring unit for measuring the weight of the medium;
genital nutrient discharge part
a lower plate inclined downward in a direction away from the delivery frame;
The front end of the lower plate is bent upward to form a pair, spaced apart from each other to form a space for discharging the nutrient solution, and forming a predetermined angle with each other to form a pair that gradually approaches each other as the distance from the center of the lower plate increases of guide plate; and
A medium moisture content measuring apparatus comprising a; one side of the pair of guide plates is bent toward the rear end of the lower plate, respectively, and coupled to the guide part to be movably coupled in the longitudinal direction of the medium frame. According to claim 1,
The coupling plate is provided with a coupling slit to be coupled to the guide part,
The guide portion is a medium moisture content measuring device, characterized in that provided with a plurality of coupling holes to which the plurality of coupling members passing through the coupling slit are fastened. delete 3. The method of claim 2,
The medium moisture content measuring device, characterized in that the plurality of coupling holes are aligned in the longitudinal direction of the medium frame. According to claim 1,
The medium weight measuring unit
an upper panel provided with an upper support part protruding upward so that the delivery frame can be seated;
a load cell having an upper protrusion coupled to the upper panel at one end and a lower protrusion at the other end opposite to the one end; and
A medium moisture content measuring device comprising a; a lower panel coupled to the lower protrusion and provided with a lower support protruding downward. 6. The method of claim 5,
the upper support
The medium water content measuring apparatus, characterized in that the medium is formed to be spaced apart along the longitudinal direction of the discharge frame to form a plurality, and the discharge frame is formed to be rotatable by a predetermined angle about a part of the upper support part due to the shifting of the weight. delete delete delete delete delete delete delete delete delete

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