KR20010079061A - Optimization Method of Variable Temperature Control of Greenhouse Facilities using Stepless Variable Set-point Generator referred to Insolation Amount Estimation - Google Patents

Abstract

PURPOSE: A method for maintaining optimum temperature necessary for the growth of a plant and saving energy by changing the set temperature and time of a variable temperature control system of a green house steplessly in proportion to insolation is provided, which can control the growth of the crops under optimum conditions and saves energy. CONSTITUTION: The method for optimization of variable temperature is achieved by using a temperature control system of a green house for cultivating vegetable and fruit, which contains a device for measuring insolation, a temperature setting device, a variable temperature controller and a controller including a curtain and air conditioning apparatus for controlling temperature by the control amount of the variable temperature controller.

Description

Optimization method of Variable Temperature Control of Greenhouse Facilities using Stepless Variable Set-point Generator referred to Insolation Amount Estimation}

The present invention is a field of farming automation technology for temperature control aimed at controlling the growth and energy saving of crops in the cultivation facilities of crops represented by greenhouse facilities.

Plants grow under the influence of environmental conditions, such as light, temperature, humidity, carbon dioxide concentration, and wind speed, as well as near-field conditions, such as acidity, electrical conductivity, liquid temperature, and dissolved oxygen concentration. In particular, the irradiation time and insolation of sunlight are critical factors in physiological reactions and growth such as photosynthesis, current, respiration, etc., and the introduction of temperature control that changes the greenhouse temperature according to the recent insolation is due to this fact.

The control of greenhouse cultivation temperature, so-called alternating temperature control, is a method of estimating the amount of insolation and setting a specific pattern of temperature appropriate for crop growth control and energy saving.

The conventional temperature control method has a time zone setting method for setting the temperature step by step according to the time of day (curve 37 of Figure 3) and the solar radiation setting method (steps 33 and 36 of Figure 3) to be set in proportion to the amount of insolation. .

The time zone setting method, which is a conventional method, is an improvement of the conventional method of setting a constant temperature of a cultivation facility, and is based on experimentally obtained set temperature and time zone data in consideration of insolation (but not directly receiving insolation data). A stepped set temperature pattern, that is, a method of generating a set temperature trajectory leading to a hop start temperature 31 → a photosynthesis acceleration temperature 32 → a current acceleration temperature 37 → a hop suppression temperature 35 of FIG. 3.

The stepwise solar radiation setting method, which is a conventional method, is an improved method of the time zone setting method, and simultaneously measures and references the solar radiation, and simultaneously changes the current acceleration temperature and the current acceleration time in several steps according to the results of the solar radiation evaluation, and at the same time, the hop suppression temperature at the current acceleration temperature. This is a method of setting the transition of the furnace (curve 34 of FIG. 3) in proportion to the amount of insolation. That is, the solar radiation data is evaluated and the set temperature pattern corresponding thereto, i.e., the hop start temperature 31 → photosynthesis promotion temperature 32 → current promotion temperature (36 → 34 depending on 33 or the solar radiation) → hop suppression temperature ( It is a method to generate the set temperature trajectory leading to 35).

The stepwise insolation setting method, which is a conventional method, sets a temperature in proportion to the insolation amount compared to the induction time setting method, so that the growth control of crops is more effective and reduced (with respect to the curves 37 and 36 and 34 of FIG. 3). The energy saving effect is proportional to the area).

However, in the stepped solar radiation setting method, the optimum temperature cannot be set because the management time and level of the set temperature are changed step by step, and the burden of the control output is large and the time zone is fixed due to the sudden change in the set value. It can be pointed out that there is a problem in terms of adaptability and energy saving.

The present invention is a method that can realize optimal temperature control in terms of plant growth and energy saving by varying the set temperature and time zone of the greenhouse temperature control system in proportion to the amount of solar radiation.

Plants basically grow by photosynthesis. Carbohydrates produced by photosynthesis make up the plant through biosynthesis along with amino acids produced by nitrogen assimilation by moving from leaves to other organs. The energy required for this action comes from the oxidation of carbohydrates by respiration. As such, physiological reactions and growth such as photosynthesis, current, and respiration are highly dependent on environmental conditions, so environmental control is a technique for optimizing plant growth.

The technical problem to be achieved by the present invention is to devise a method that can effectively control the environmental conditions according to the evaluation of insolation in relation to the fact that physiological reactions and growth, such as photosynthesis, electric current, hop hop of the plant is related to insolation will be.

Compared to the conventional method for setting the time zone or the stepwise solar radiation setting method, the photosynthesis promotion time and the current promotion time are varied in conjunction with each other, and the current promotion temperature is also varied, and the temperature and time are set steplessly and continuously. It is to devise a temperature control method characterized by setting both temperature setting level and time zone without permission, continuous and automatic. In other words, it is possible to realize the optimum temperature control in terms of plant growth and energy saving, and to invent a flexible method for the applied crop varieties and climatic environments.

1 is a characteristic curve of the solar radiation evaluation type stepless variable set value generator according to the present invention.

2 is a block diagram of a solar radiation evaluation type stepless variable temperature setting greenhouse temperature control system according to the present invention.

3 is a set temperature curve of conventional solar radiation temperature control.

<Description of the reference numerals for the main parts of the drawings>

11: temperature process 12: manipulator

13: temperature controller 14: set temperature generator

15: solar radiation sensor 16: solar radiation evaluation mechanism

17: temperature sensor

21: Hoping start temperature 22: Photosynthesis promotion temperature

23: Current promotion temperature (sunny) 24: Current temperature proportional to the amount of insolation (sunny)

25: Hop Hop Inhibition Temperature 26: Current Promotion Temperature (Ratio)

27: current temperature proportional to insolation

28: Extended photosynthesis promotion time on a sunny day

29: conventional time setting temperature pattern

31: Hoping start temperature 32: Photosynthesis promotion temperature

33: current promotion temperature (sunny) 34: current temperature proportional to insolation

35: hop hop suppression temperature 36: current promotion temperature (ratio)

37: temperature setting pattern by time

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a solar radiation evaluation type stepless variable temperature setting greenhouse temperature control system according to the present invention.

In Fig. 1, 11 is a temperature process, 12 is a manipulator, 13 is a temperature controller, 14 is a set temperature generator, 15 is a solar radiation sensor, 16 is a solar radiation evaluation mechanism, and 17 is a temperature sensor.

In the temperature process 11 in FIG. 1, the purpose of the control is to make the actual greenhouse temperature output as the target of the temperature control to be equal to the set temperature which is the output of the set temperature generator 14. The set temperature generator 14 generates a set temperature signal to which the output of the temperature process 11 to be controlled should follow while referring to the insolation data, which is the output of the insolation evaluation mechanism 16 that measures and evaluates the insolation amount.

In Fig. 1, the variable temperature controller 13 generates a control signal such that the difference between the fed back actual greenhouse temperature and the output of the set temperature generator, that is, the deviation becomes zero, is a proportional + integral + derivative control algorithm such as a proportional control algorithm. It may be equipped with a fuzzy, neural network or artificial intelligence.

In FIG. 1, the manipulator 12 is a skylight and a curtain for curtains, a cooler, a heater, and the like, an operation signal for opening or closing a curtain according to a control signal output from the temperature controller 13, or an operation signal for starting or stopping a cooler or a heater. Occurs. The actual greenhouse temperature will then follow the set temperature pattern.

In FIG. 1, the solar radiation sensor 15 is an element for detecting the solar radiation, and the temperature sensor 17 is a detector for detecting the actual temperature of the greenhouse.

2 is a characteristic curve of the solar radiation evaluation type stepless variable set value generator according to the present invention.

2, 21 is the hop start temperature, 22 is photosynthesis promotion temperature, 23 is the current promotion temperature (sunny), 24 is the current temperature (clear) in proportion to the amount of insolation, 25 is the hop suppression temperature, 26 is the current promotion temperature (ratio) , 27 is a current temperature (ratio) proportional to the amount of insolation, 28 is a photosynthesis promotion time on a sunny day, and 29 is a conventional time-specific temperature setting pattern.

2 shows a set temperature trajectory or pattern to which the actual greenhouse temperature should be followed, wherein the set temperature pattern on a sunny day is the trajectory of the curve 21 → 22 → 28 → 23 → 24 → 25, and the pattern on the rainy day is 21 →. Show the same as the trajectory of 22 → 26 → 27 → 25.

The photosynthesis promotion temperature 22 in FIG. 2 is a temperature level set high with the intention of promoting photosynthesis during the day while the sun is floating. When this photosynthesis promotion time is over. The set temperature of the greenhouse is set to a current accelerating temperature 23 for moving carbohydrates produced by photosynthesis to other parts of the leaves of the crop. The time and set temperature for current promotion are varied for crop growth control and energy saving purposes.

In Fig. 2, the set temperature level and the current acceleration time are set variably according to the amount of insolation, which is set along the trajectory of curve 22 → 28 → 23 → 24 → 25 on sunny days and curve 22 → 26 → 27 → on rainy days. The temperature is set along the trajectory of 25, and in the weather between the sunny day and the rainy day, the trajectory between the two trajectories is set according to the result of the solar radiation evaluation. The method of the present invention is characterized by automatically generating an optimum set temperature pattern at all times in response to changes in the amount of solar radiation according to the weather and climate, and the advantage is that the conventional stepwise finite patterns (usually four) This is clearly different from varying the set temperature.

In Figure 2, the hop suppression temperature (25) allows the crop to sleep during the deep night, and the hop start temperature (21) is the temperature at which the plants wake up at dawn until the sun rises to prepare for photosynthesis.

3 is a set temperature curve of conventional solar radiation temperature control.

In Figure 3, 31 is the start of the hop start temperature, 32 is the photosynthesis promotion temperature, 33 is the current promotion temperature (clear), 34 is the current temperature in proportion to the amount of insolation, 35 is the hop suppression temperature 36 current promotion temperature (rain), 37 is time zone Each temperature setting pattern is shown.

3 shows a set temperature trajectory or pattern to be followed by the actual greenhouse temperature, wherein the set temperature pattern on a sunny day is the trajectory of the curve 31 → 32 → 33 → 35, and the pattern on a rainy day is 31 → 32 → 36 → 34. → It shows the same as the trajectory of 35.

In FIG. 3, the description of the set temperature level and time leading to the hop start temperature 31, the photosynthesis promotion temperature 32, the current promotion temperature 33, and the hop suppression temperature 35 is similar to that of FIG. 2. It will be omitted here, the difference from the description of Figure 2 of the present invention is as follows.

In Figure 3, the set temperature level and the current acceleration time are set to be variable according to the amount of insolation, which is set along the trajectory of curve 31 → 32 → 33 → 35 for very clear days, and curve 31 → 32 → 36 → 34 → for rainy days. The temperature is set along the trajectory of 35, and the weather between a sunny day and a rainy day is classified into only two sunny and cloudy days and generates a set temperature level and time according to the corresponding trajectory. In the conventional method, only a finite number of set temperature patterns (four here) can be pointed out, and each set section is fixed. Therefore, an optimum set temperature pattern is always provided in response to changes in solar radiation according to weather and climate. It is clearly different from the method of the invention, which occurs automatically.

The method of the present invention is similar to the conventional method of setting time zones and stepwise insolation in that it realizes temperature control of a plant for crop cultivation in consideration of insolation, but the mechanism for generating the set temperature is clearly as described above. different.

The method of the present invention is a method in which the set temperature and time zone are changed in an unauthorized manner according to the amount of insolation, and only a finite number of temperature setting patterns in which the management time and level of the set temperature are changed step by step, the operation amount is changed rapidly, and the time zone is fixed It is a method that fundamentally solved the problem of temperature change management shown by the conventional stepwise insolation setting method.

The method of the present invention is characterized by automatically generating an optimum set temperature pattern at all times in response to changes in the amount of insolation due to weather and climate, and as a result, in the conventional method of varying the set temperature according to a finite number of patterns step by step. Compared with the following effects.

ㆍ Flexibility in application: Compared to the conventional method of performing temperature control using only finite set temperature patterns, the method of the present invention can generate a myriad of set temperature patterns, and thus, various kinds of crops are applied and growth control is fine. And the climate and climate zones to which it applies

ㆍ Optimization of crop growth: Compared with the conventional method of generating finite set temperature step by step, the method of the present invention is capable of simultaneously changing the level and time zone of the set temperature steplessly and optimally, so it is optimal in terms of crop growth control. Control can be realized

Energy saving and efficient use: The method of the present invention, which is capable of simultaneously changing the level of the set temperature and the time zone section without permission, continuously, can also optimize energy saving. Moreover, unlike the conventional method, the amount of operation is drastically changed, but in the method of the present invention, the energy consumption is continuous as it is continuously changed, which realizes smoothing or efficiency of energy utilization.

Applicable to various control methods: The conventional method of generating finite set temperature step by step is suitable for constructing on-off control or sequence control system which is proportional to the amount of solar radiation when analyzed by the control method. On the other hand, the method of the present invention can simultaneously and continuously vary the level and time zone of the set temperature steplessly and continuously, so that not only the setpoint generator, but also the applied PID (Proportional + Integral + Derivative) control, application feedforward / feedback to the entire temperature control system. It is evaluated that the possibility of applying various control methods such as (Advanced Feedforward / Feedback) control, AI and adaptive control that adopts fuzzy or neural network circuits is prepared.

Claims (3)

In the temperature control system of greenhouse facilities for growing vegetables and fruits: An insolation dose evaluation mechanism for measuring insolation amount by inputting data detected using an insolation sensor and evaluating the level of insolation intensity; A set temperature generator for determining a set temperature pattern according to the solar radiation evaluation data; A temperature controller for outputting a control signal to zero the difference between the temperature set value output from the set temperature generator and the actual temperature detected by the greenhouse temperature sensor, a curtain for controlling the temperature according to the control amount output from the temperature controller. A manipulator including a heating device; And a temperature process subject to control. The method according to claim 1, wherein a set temperature level and a time zone section (or a set temperature pattern) are determined steplessly, continuously and automatically according to the insolation evaluation data output from the insolation evaluation apparatus. The greenhouse temperature change according to claim 1, wherein various control methods such as applied PID control, applied feedforward / feedback control, artificial intelligence and adaptive control employing a fuzzy or neural network are applied to the set temperature generator or the temperature change controller. Control method.