KR20210014462A - 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 device for measuring a moisture content of a medium and a method for calculating an inflow and outflow content of moisture of a medium capable of reducing manufacturing costs, providing an excellent assembly property, and calculating the inflow and outflow content of the moisture of the medium with only a weight of the measured medium. Provided is the device for measuring a moisture content of a medium comprising: a medium frame which includes a mounted surface in which the medium is mounted and a bottom surface which is lower than the mounted surface, and includes a guide unit which guides a nutrient solution which is dropped by being discharged from the medium to one direction; a nutrient solution discharging unit which is moved in the medium frame, and collects and discharges the nutrient solution guided from the guide unit; and a medium weight measuring unit which measures 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 a medium moisture content measuring device and a method of calculating the amount of water outflow of a medium, and more particularly, a medium water content capable of calculating the amount of water outflow of a medium only by the weight of the measured medium, which has excellent assembly properties while reducing manufacturing cost. It relates to a measuring device and a method of calculating the amount of water outflow of a medium.

Nutrient solution irrigation (Irrigation) is a nutrient solution that contains essential elements required for plant growth according to a set composition ratio after planting or sowing plants in a medium without using land and planting them in various ways. It means a plant cultivation method that supplies for plant growth. The cultivation of plants through nutrient solution irrigation is actively used for mass production of plants as it can precisely and uniformly control the environment of the soil in which plants are planted, unlike the method of planting plants on the land. In addition, the plant cultivation method through nutrient solution irrigation is more widely used as it is possible to establish a plant cultivation area through nutrient solution irrigation even in a space where plant cultivation is difficult due to sufficient land security or land contamination.

Plant cultivation through nutrient solution irrigation is greatly influenced by the appropriate water content in the medium. In general, when the water content in the medium is high, the crop will grow vegetatively, and when the water content is low, the crop will grow. However, an excessively high water content in the medium adversely affects the roots of the crop, and an excessively low water content improves the growth of the roots, but proper management is important as the crops can easily wither and harm under strong light conditions.

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 Registration 10-1326596. However, since sidewalls are formed at the edge of the tray on which the medium is placed, the drainage is collected, so accurate water content measurement is not performed.An additional process called welding is required to form the sidewall, and a welding process is also added to the structure to collect the drainage. There is a problem that is required.

Furthermore, the large size of the accessories interferes with the working radius in the greenhouse, and the height of the sample medium to be weighed is higher than that of other conventional mediums, so the amount of liquid supply may be different due to the difference in the head (pressure) of the dripper. Since there are many kinds of accessories, there is a problem 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 in the fastening area.

In addition, in the case of the top tray on which the medium is placed, structure welding is required for water collection, and water is accumulated at the edge of the corner or in the area in contact with the medium, resulting in inaccurate measurement values, as well as the accumulation of foreign substances such as green algae or due to a humid environment. There is a problem that can be a starting point for damage to 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. The growth of crops can be controlled by using the difference in water content per day. For example, plants are cultivated through nutrient solution irrigation while the change in daily moisture content is maintained at 6-8%, 8-10% when inducing reproductive growth, and 4-6% when inducing vegetative growth. However, it is not a simple task to measure moisture in the medium and make appropriate changes.

A nutrient solution cultivation management device was devised and commercialized through Korean Patent No. 10-1843883 in order to measure the moisture in the medium and give appropriate changes.Through this nutrient solution cultivation management device, the slab weight and nutrient solution showing a constant pattern according to time change The nutrient solution can be automatically managed when an abnormality occurs in nutrient solution management based on the amount of supply and drainage. However, in order to measure the weight of the slab, the amount of liquid supply, and the amount of drainage, the supply detection unit including sensors, the drainage detection unit, and the weight detection unit are separately provided, which increases the manufacturing cost, and the measurement value is inaccurate due to frequent breakdowns and maintenance. There was a problem that was not easy.

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

In addition, the present invention is to provide a method of calculating the amount of water outflow of a medium capable of calculating the amount of water outflow of a medium without installing a sensor in the province.

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

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

The genital nutrient solution discharge unit 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 respectively bent to be coupled to the guide portion.

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

The discharge weight measuring unit includes an upper panel having an upper support part protruding upward so that the discharge 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 that is coupled to the lower protrusion and protrudes downward.

The upper support part may be spaced apart along the longitudinal direction of the discharge frame to form a plurality, and the discharge frame may be rotated by a predetermined angle around a part of the upper support part by weight shift.

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

In the step of calculating the supply liquid supply section, 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 is not discharged from the medium, and thus the amount of increase and supply liquid may be calculated.

In the step of calculating the supply liquid supply section, if the measured change rate is not similar to the first reference change rate, it is determined that the nutrient solution is supplied to the medium and discharged from the medium, thereby calculating an increase amount, a supply liquid amount, and a drainage amount.

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

In the step of calculating the non-supplying section, if the measured rate of change is similar to the second reference rate of change, it is determined as a section in which the nutrient solution is discharged from the medium, and the amount of increase and the amount of drainage may be calculated.

In the non-supplying section calculation step, if the measured rate of change is not similar to the second reference rate of change, it may be determined as a section in which nutrient solution is not discharged from the medium, and the amount of increase may be calculated.

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

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

The second reference rate of change in the second non-supply period calculation step may be used to calculate the amount of increase in the supply-supply period calculation step performed after the first non-supply period 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 measurement device can be manufactured with a simple structure, maintenance is easy, accurate measurement values can be obtained, and inexpensive manufacturing is provided.

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

Third, according to an embodiment of the present invention, it provides an effect that can be quantitatively measured in a medium-based crop rather than 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.

Fourth, according to an embodiment of the present invention, a precise irrigation strategy is established through quantitative water movement monitoring in a plant, and an effect of maximizing production through optimal cultivation conditions is provided.

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

The embodiments described below are illustratively shown to aid understanding of the invention, and it should be understood that the present invention may be variously modified and implemented differently from the embodiments described herein. However, in describing the present invention, when it is determined that a detailed description of a related known function or component may unnecessarily obscure the subject matter of the present invention, the detailed description and detailed illustration thereof will be omitted. In addition, the accompanying drawings are not drawn to scale to aid 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 elements, but the elements should not be limited by terms. The terms are only used for the purpose of distinguishing one component from another component.

In addition, terms used in the present application are only used to describe specific embodiments, and are not intended to limit the scope of the rights. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise", "consist of" or "consist of" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, one or It is to be understood that no further features or possibilities of the presence or addition of numbers, steps, actions, components, parts, or combinations thereof are precluded.

FIG. 1 is a perspective view showing a medium water content measuring device 1 according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view illustrating the medium water content measuring device 1 illustrated in FIG. 1. 1 and 2, the medium water content measuring device 1 according to an embodiment of the present invention includes a medium frame 100, a nutrient solution discharge part 300, and a medium weight measuring part 500.

The discharge frame 100 includes a frame body 110 formed to seat a medium and a guide part 130 provided on at least one side of the frame body 110 to guide the nutrient solution discharged from the medium in one direction.

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

The guide part 130 forms a long flow path in which a space is formed so that the nutrient solution discharged from the culture medium seated on the seating surface may fall and be temporarily accommodated. The guide part 130 is provided under the frame body 110. Specifically, the guide portion 130 is formed extending upward from one end of the bottom surface 131 and the bottom surface 131 having a height lower than the seating surface, and the inner wall 133 coupled to the frame body 110, the bottom surface ( It includes an outer wall 135 extending upward 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 unit 300 to be described later is movably coupled.

Meanwhile, the discharge frame 100 may be integrally formed with the frame body 110 and the guide part 130. Specifically, the inner wall 133, the bottom surface 131, and the outer wall 135 of the guide unit 130 described above may be formed by bending an edge of one plate constituting the discharge 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 cost.

Since the discharge frame 100 does not have a side wall surrounding the seating surface, the nutrient solution discharged from the discharge medium does not accumulate on one side and falls directly to the guide unit 130. Since the discharge frame 100 is seated downwardly inclined in one direction by the discharge weight measuring part 500 to be described later, the dropped nutrient solution is guided in one direction through the guide part 130.

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

3 and 4, the nutrient solution discharge unit 300 is movably provided on the discharge frame 100 and performs a function of collecting and discharging the nutrient solution guided from the guide unit 130.

The nutrient solution discharge part 300 has a coupling slit 351 formed on one side thereof, and is movably coupled to the guide part 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 long 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 part 300 has a receiving space 371 temporarily receiving the nutrient solution therein, and a lower plate 310 forming a bottom, a guide plate extending upward from the front end of the lower plate 310 330 and the guide plate 330 includes a coupling plate 350 extending from the side end toward the rear end of the lower plate 310.

The lower plate 310 is disposed below the discharge frame 100 and is disposed to be inclined downward in a direction away from the discharge 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 is discharged by moving to a lower side of the lower plate 310 along the lower plate 310.

The guide plate 330 has a discharge space for discharging at one side so that the nutrient solution moved along the lower plate 310 is discharged. In addition, the guide plate 330 forms a predetermined angle around the discharge space. Therefore, the guide plate 330 can prevent the nutrient solution from accumulating 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 most distant from the discharge space. The coupling plate 350 is provided in a pair, and is provided with a coupling slit 351 elongated to be movably coupled to the outer wall 135 of the guide portion 130 described above. 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 portion 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 to form a guide plate 330 by bending the tip upward, and bending one side of the guide plate 330 to form a coupling plate 350 Can be formed. In this case, there is no need for welding, 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. FIG. 5 is a perspective view showing the discharge weight measuring unit 500 shown in FIG. 1, and FIG. 6 is a diagram illustrating a coupling relationship between the discharge weight measuring unit 500 and the discharge frame 100 illustrated 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 discharge frame 100 can be seated. Specifically, the upper panel 510 is formed in a plate shape, but the edge is bent downward to secure the strength to form the upper flange 513.

The upper panel 510 is provided with a plurality of upper support portions 511 for supporting a load. The height of the upper support part 511 is adjusted so that the supported object may be inclined. The above-described discharge frame 100 is also seated on the upper support part 511 and is disposed to be inclined by the upper support part 511.

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

In the load cell 530, upper protrusions 531 protruding upward from the upper side are provided on the upper surfaces of both ends, and lower protrusions 533 protruding downward from the lower side are 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 and couples 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 so that the load cell 530 is seated. Specifically, the lower panel 550 is formed in a plate shape, and the edge is bent upward to secure strength to form a lower flange 553.

A plurality of lower support portions 551 supporting the lower flange 553 are provided on the lower surface of the lower panel 550. The height of the lower support part 551 is adjusted, and the height of each of the lower support parts 551 may be adjusted so that the discharge weight measuring part 500 is horizontal.

Meanwhile, referring to FIG. 6, when the plate PL on which an object such as the discharge frame 100 is placed is mounted 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, there may be a case where a load is applied to one side like an 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, and eventually the load cell 530 is permanently beyond the maximum allowable load range of the part to which the upper coupling piece 561 is coupled or the load cell 530. It can damage it.

In order to solve this problem, the medium moisture content measuring apparatus 1 according to an embodiment of the present invention only supports the load of the discharge frame 100 by the upper support part 511 and does not combine with the discharge frame 100. Accordingly, when the load is shifted, it may occur because the discharge frame 100 rotates around the upper support part 511.

Hereinafter, a method of calculating a water outflow amount of a 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 in the amount of water outflow of the medium measured by the medium weight measuring unit 500 shown in FIG. 1, and FIG. 8 is an enlarged view of a portion indicated by P in FIG. 7.

7 and 8, the method of calculating the water outflow amount of the medium according to an embodiment of the present invention calculates the water outflow amount of the medium through the measured change rate derived by measuring the change rate of the medium weight in which plants are planted, and Do not use sensors to measure values other than the weight value.

In general, in crops grown with medium-based nutrient solutions such as tomatoes, paprika, and cucumbers, the growth of the crop 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 given little by little and many times at a long time interval, the amount of nutrient supply, drainage, and transpiration of plants can be quantified and monitored to establish an irrigation strategy.

By measuring the weight of the medium, it is possible to quantitatively grasp not only the water content of the medium, but also the pattern in which the crop absorbs (evaporates) moisture. Here, the water content of the medium is an index indicating the amount of water in the medium. Water content based on volume, which is the ratio of the volume of water to the volume of the medium, is sometimes used.

Using the transpiration value of the crop calculated by measuring the weight of such a medium, it is possible to receive help in setting the amount of one-time supply, supply interval, irrigation start and end time, etc. that are entered into the nutrient system. An appropriate irrigation method can be suggested according to the growing state.

Conventional water content measuring devices have a large volume occupied in the cultivation space, which affects the working radius and accurate measurement, and the production cost is large due to the large number of accessories and fastening parts. In addition, in the case of the upper tray used in the conventional water content measuring device, the measurement is inaccurate due to the accumulation of water, and it could be a cause of accumulation of foreign matter or pests. Further, in order to measure the amount of liquid supply, amount of drainage, amount of transpiration, etc., separate sensor installation is required, which increases manufacturing cost and maintenance items, and there is a problem in that inaccurate measurement is made due to the occurrence of green algae and fertilizer crystallization.

Accordingly, the method of calculating the water outflow amount of the medium according to an embodiment of the present invention uses the above-described medium water content measuring device 1, and calculates the water outflow amount of the medium by measuring the weight of the medium and its change amount (instantaneous slope). The amount of water in and out of the medium is the amount of water supply, amount of drainage, and amount of transpiration. The calculation of the amount of water inflow and outflow 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 such as vinyl that prevents moisture from evaporating into the air from the medium in order to accurately calculate the transpiration amount measurement.

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

The increase in crop production occurs 24 hours a day (performs), and as shown in FIG. 7, the increase in production line TR is inclined upward toward the right from midnight to midnight the next day. The transpiration of crops is actively carried out during the daytime and slower at night, and the slope of the night time is smaller than that of the daytime, even in the graph of FIG. 7.

The supply solution for supplying the nutrient solution to the medium is not performed during the night time, but is performed multiple times at predetermined intervals during a certain time during the day time. When the supply is made and the nutrient solution exceeds the maximum moisture content of the medium, the nutrient solution is discharged from the medium, and drainage is performed.

As shown in FIG. 7, the weight line WE indicating 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 amount of liquid supply can be adjusted so that the medium that has dried during the night time does not absorb and discharge all the moisture.

At this time, the medium weight line WE is used as the first standard change rate SUref, which will be described later. The first reference rate of change (SUref) refers to a rate of change in weight of a medium in which supply is performed but no drainage is performed from the medium.

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

After that, the supply is performed several times at predetermined time intervals. Accordingly, the discharge weight line WE represents a sawtooth wave. In the evening, the supply is stopped, and the weight line WE is formed to be inclined downward to the right.

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

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

During the daytime, the supply section (S10) and the drain section (S30) correspond to the sawtooth wave portion 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 supply is started from a first time point (ta), a drainage of the supply is performed from a second time point (tb), and from a third time point (tc), the supply is stopped and only the drain is performed. From point 4 (td), neither supply nor drain is performed. The section before the first point (ta) is a section in which neither supply nor drain is performed.

In this case, the drainage section (S30) in which the nutrient solution is supplied and the drainage section (S30) through which the nutrient solution is discharged are overlapped with each other, thereby forming an overlapping section (OL), and the escalation section (S50) in which crop cultivation is performed is as described above. Together, the entire section.

Hereinafter, a method of calculating the amount of water outflow 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 occurs. Area B is the area where supply and increase production are performed. Area C is the area where supply, drainage and increase of production take place. The D area is the area in which the drainage and increase are performed.

The medium weight line (WE) is, for example, the higher the altitude of the sun and the more active the transpiration activity of the crop, the higher the slope in the A'region than in the A region. Thereafter, for example, as the altitude of the sun decreases and the transpiration of crops is slowed, the medium weight line (WE) has a lower slope in the A'region than in the A region.

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

Furthermore, it is assumed that the first reference rate of change SUref is also the same in regions B and C. Accordingly, the amount of liquid supply in regions B and C can be calculated through the first standard rate of change (SUref).

In area B, supply and increase of acid are performed, and a step of comparing the weight of the medium WE and the first standard change rate SUref is performed. If it is determined that the slope of the discharge weight line WE is not similar to the first reference rate of change SUref, it is determined that region C is started. Determination of similarity is determined by, for example, a departure ratio that deviates from the first reference change rate (SUref) value, and the accuracy increases as the departure ratio is set smaller. For example, as the size of the first reference rate of change (SUref) is 10 and the size of the inclination of the weight line WE is 11, the difference between the size of the first reference rate of change (SUref) and the size of the inclination of the weight line WE If the value is 1, the departure rate can be determined as 10%.

For example, the amount of water outflow of the medium in the B area is calculated by calculating the increase in the weight of the medium through the medium weight line (WE), calculating the amount of transpiration through the second standard change rate (TR1), and adding the amount of transpiration to the increase in the weight of the medium. It is possible to calculate. As another example, the amount of water inflow and outflow of the medium in the region B 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 the C area, supply, drainage, and increase of acid are performed, the step of comparing the weight line (WE) with the first standard change rate (SUref) is not performed, and whether the slope of the weight line (WE) changes to a negative number. The determining step is performed. When the slope of the discharge weight line WE changes to a negative number, it is determined that the D area is started.

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

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

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

In the A'region, only crop transpiration is performed as described above. Therefore, the amount of transpiration is the same as the amount of medium weight reduction. In this case, for example, when a region B'having a pattern similar to that of region B starts after region A', the slope calculated for a predetermined time just before the start of region B'is set to another second reference rate of change TR2. The other second reference rate of change TR2 may be assumed to have the same value when the regions B'and regions C and D'having similar patterns to regions B, C, and D 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 liquid supply and the amount of drainage is not used.

As described above, although the present invention has been described by a limited embodiment and drawings, the present invention is not limited thereto, and the technical spirit and the following by those of ordinary skill in the technical field to which the present invention pertains. It goes without saying that various modifications and variations are possible within the equivalent range of the claims to be described in.

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

Claims (15)

A seating surface on which the medium is seated; And a guide unit including a bottom surface having a height lower than that of the seating surface and guiding the nutrient solution discharged and falling from the culture medium in one direction;
A nutrient solution discharge unit movably provided in the discharge frame and collecting and discharging the nutrient solution guided from the guide unit; And
Medium content measuring device comprising a; medium weight measuring unit for measuring the weight of the medium. The method of claim 1,
The nutrient solution discharge portion is provided with a coupling plate having a coupling slit to be coupled to the guide portion,
The guide unit, characterized in that the discharge water content measuring device is provided with a plurality of coupling holes through which a plurality of fastening parts passing through the coupling slit are fastened. The method of claim 1,
The genital nutrient discharge
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 is bent, respectively, a coupling plate formed to be coupled to the guide portion; Medium water content measuring apparatus comprising a. The method of claim 3,
The nutrient solution discharge part
The medium water content measuring apparatus, characterized in that the space through which the nutrient solution is discharged is formed by the pair of guide plates being spaced apart from each other. The method of claim 1,
The medium weight measuring unit
An upper panel provided with an upper support portion protruding upward so that the discharge 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
And a lower panel coupled to the lower protrusion and having a lower support protruding downward. The method of claim 5,
The upper support part
The discharge water content measuring device, characterized in that the discharge frame is separated along the longitudinal direction of the discharge frame to form a plurality, and the discharge frame is rotated by a predetermined angle around a part of the upper support part by weight shift. In the method of calculating the amount of water outflow of the medium through the measured change rate derived by measuring the rate of change in the weight of the medium in which plants are planted,
In the case of a supply liquid supply section in which the nutrient solution is supplied to the medium, a supply liquid supply section calculation step of comparing the measured change rate and a preset first reference change rate to calculate a water outflow amount of the medium; And
In the case of a non-supplying section in which the supply of nutrient solution to the medium is stopped, a non-supplying section calculating step of calculating the amount of water outflow of the medium by comparing the measured change rate with a preset second reference rate of change; .. The method of claim 7,
The step of calculating the supply section
When the measured rate of change is similar to the first reference rate of change, the amount of transpiration and the amount of supply liquid are calculated by determining that the nutrient solution is supplied to the medium but is not discharged from the medium, and calculates the amount of transpiration and supply. The method of claim 7,
The step of calculating the supply section
If the measured change rate is not similar to the first reference rate of change, the amount of transpiration, the amount of supply, and the amount of drainage are calculated by determining that the nutrient solution is supplied to the medium and discharged from the medium. The method of claim 7,
The first standard rate of change is
A method of calculating the amount of water outflow of a medium, characterized in that the amount of water in and out of the medium is calculated during a predetermined period in which no drainage is performed after the supply of the nutrient solution is first started after maintaining a state in which no nutrient solution is supplied for a predetermined period. The method of claim 7,
The step of calculating the non-payment section is
When the measured change rate is similar to the second reference rate of change, the amount of transpiration and drainage are calculated by determining that the nutrient solution is discharged from the medium. The method of claim 7,
The step of calculating the non-payment section is
If the measured change rate is not similar to the second reference rate of change, it is determined as a section in which the nutrient solution is not discharged from the medium, and the amount of transpiration is calculated. The method of claim 7,
The non-supply section calculation step includes a first non-supply section calculation step performed before the supply section calculation step and a second non-supply section calculation step performed after the supply section calculation step,
The second reference rate of change in the second non-supplying section calculation step is calculated while the supply and drainage are stopped for a predetermined period before the end of the first non-supply section calculation step. . The method of claim 13,
The step of calculating the non-supply section and the step of calculating the supply section are alternately performed,
The second reference rate of change is calculated for each step of calculating the non-supplying section. The method of claim 13,
The second standard rate of change in the step of calculating the second non-payment section is
The method of calculating the amount of water outflow of a medium, characterized in that it is used for calculating the amount of increase in the step of calculating the feed section performed after the step of calculating the first non-feed section.

Images