CN112806195B - Precise control method of micro-sprinkler irrigation for seedling raising in greenhouse - Google Patents

Abstract

The invention relates to the field of agricultural sprinkling irrigation, in particular to a micro-sprinkling irrigation precision control method for greenhouse seedling culture. The method comprises the following steps: s1, establishing a crop growth cycle model, and performing multi-pole combination on electrodes of a multi-pole sensor; s2, measuring the relative humidity around the seedlings in a non-micro-sprinkling irrigation state by using a multi-pole sensor according to an actual crop growth period model, and starting a micro-sprinkling irrigation sprayer when the measured relative humidity is lower than a set value; s3, starting the micro-sprinkling irrigation nozzle, automatically switching two working electrodes of a multi-stage sensor, and measuring the water demand of the micro-sprinkling irrigation state by using the multi-stage sensor; and S4, after the micro-sprinkling irrigation is finished, automatically switching two working electrodes of the multi-stage sensor, and repeating S2 and S3. The device can accurately measure the relative humidity value of the seedling production environment, accurately control the water demand in the micro-sprinkling irrigation process, realize the automatic, large-scale and remote production of greenhouse seedling, and greatly improve the production quality of greenhouse seedling.

Description

Precise control method of micro-sprinkler irrigation in greenhouse seedling raising

technical field

The invention relates to the field of agricultural sprinkler irrigation, in particular to a method for precise quantity control of micro-sprinkler irrigation in greenhouse seedling cultivation.

Background technique

At present, nursery mainly relies on artificial experience for sprinkling irrigation, and it takes 4-5 years for general technicians to have certain experience in sprinkling irrigation. This method of sprinkling irrigation for seedlings is not only time-consuming and labor-intensive, but more importantly, in order to keep the humidity of the seedlings at a constant humidity, excessive water is applied to the seedlings, which may easily lead to failure of the seedlings. In recent years, the factory-based seedling breeding technology in various countries has developed rapidly in the cultivation of vegetables, flowers, tea gardens and other seedlings. Micro-sprinkler irrigation is one of the important links in seedling cultivation. Micro-sprinkler irrigation technology can not only effectively improve the utilization efficiency of water resources, but also It can improve the production quality of seedlings.

my country's greenhouse production started late and belongs to an emerging industry. Greenhouse seedling cultivation is in its infancy, with a low degree of automation, which is not conducive to large-scale production. At this stage, it is in the initial stage of micro-sprinkler irrigation. At present, there is little information on how to irrigate seedlings. Only by spraying water can the seedlings be free from the impact of water, and how to automatically spray water. In the existing semi-automatic research results, there is no equipment for detecting leaf moisture, but soil temperature, soil humidity, and air temperature are mainly used as irrigation control parameters for plants. These control methods have the following shortcomings: (1) Unable to Accurately realize the adjustment of plant water demand; (2) It is easily interfered by various factors such as temperature and salt accumulation in the soil; (3) The existing semi-automatic devices are not only expensive, but also difficult to grasp the degree of sprinkler irrigation required by different plants. Easy to shock damage to seedlings.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the above-mentioned defects in the prior art, and propose a method for controlling the precision of micro-sprinkler irrigation in greenhouse seedling cultivation, which can accurately measure the relative humidity value of the seedling production environment and accurately control the water demand in the process of micro-sprinkler irrigation, The automatic, large-scale and remote production of greenhouse seedlings can be realized, and the production quality of greenhouse seedlings can be greatly improved.

The technical scheme of the present invention is: a method for controlling the precision of micro-sprinkler irrigation for growing seedlings in a greenhouse, comprising the following steps:

S1. According to the humidity and water demand required by different crop growth cycles, establish a crop growth cycle model, and perform multi-pole combination on the electrodes of the multi-pole sensor:

The multi-pole sensor includes a cylindrical insulator and a plurality of electrodes arranged in the axial direction in the insulator. The electrodes are arranged at intervals in the insulator, and the spacing between the electrodes is unequal. One end of the electrode is exposed to the outer end of the insulator. , the other end of the electrode is located in the insulator, and an analog resistor is connected between any two electrodes of several electrodes;

S2. According to the actual crop growth cycle model, switch on two electrodes with a distance of 2-8mm in the multi-stage sensor, and use the multi-pole sensor to measure the relative humidity around the seedling in the non-micro-sprinkling state. When the measured relative humidity is lower than the set When the value is fixed, start the micro-sprinkler sprinkler, and the calculation formula for relative humidity (%) measurement is as follows

Among them, F is the relative humidity value, Y is the distance between the two working electrodes, the unit is mm, and Z is the analog resistance value connecting the two working electrodes, the unit is KΩ;

S3. When starting the micro-sprinkler sprinkler head, automatically switch the two working electrodes of the multi-level sensor, connect the two electrodes with a distance of 6-12mm in the multi-level sensor, and use the multi-pole sensor to measure the water demand in the micro-sprinkler state:

The water demand measurement of the micro-sprinkler irrigation state is realized by controlling the micro-sprinkler irrigation time. The calculation formula of the micro-sprinkler time L of the micro-sprinkler irrigation nozzle is as follows

L=-0.7424+1.3440X+22.1517/Z Among them, the unit of L is s, X is the distance between the working electrodes, the unit is mm, Z is the analog resistance value connecting the two working electrodes, the unit is KΩ, when the micro-sprinkler irrigation When the micro-irrigation time of the sprinkler head reaches the L value, the micro-sprinkler sprinkler head is turned off;

S4. After the micro-sprinkler irrigation is completed, the two working electrodes of the multi-level sensor are automatically switched, and the electrodes with a distance of 2-8 mm in the multi-level sensor are switched on, and S2 and S3 are repeated.

In the present invention, six electrodes can be set in the insulator, and any electrodes in the six electrodes can be combined in two to form fifteen groups of electrode sensors, and each group of electrode sensors can complete the measurement of relative humidity in a non-sprinkling state or a sprinkling state. Measurement of water demand.

The micro-sprinkler sprinkler head includes a steel column, a nozzle, a connecting water pipe and a U-shaped spring, the nozzle is arranged in a vertical direction, a water spray hole is arranged in the nozzle, the length of the nozzle is 2-4cm, and the nozzle is connected to the water supply through the connecting water pipe at the bottom of the nozzle. Pipe connection, there is a steel column above the nozzle, the top of the nozzle is connected to the steel column above it through a U-shaped spring, the calculation formula of the diameter d of the water spray hole is:

Among them, d is the diameter of the nozzle, the unit is mm, p is the injection pressure, the unit is bar, q is the injection flow, the unit is L/min, n is the number of nozzles, η is the nozzle efficiency coefficient, η=1.05-1.10.

The diameter of the water spray hole of the nozzle is preferably 0.8-1.2 mm. When the diameter of the water spray hole is 0.8mm, the spray effect is the best, the spray water is uniform, and the water droplet density is reasonable.

The set value in the above S2 is 66%-100%.

The precise quantity control method of micro-sprinkler irrigation in greenhouse seedling raising described in the present application is realized by the precise quantity micro-sprinkling irrigation system in greenhouse seedling raising. The sensor and micro-sprinkler sprinkler are connected, and the control mechanism adopts the main control system based on single chip microcomputer. The single-chip microcomputer can use the single-chip microcomputer of the STC15 series, or other types of single-chip microcomputers.

The beneficial effects of the present invention are:

(1) The multi-pole sensor in the present invention is placed in the outer space of the soil, feels the spray amount synchronously with the seedling, can accurately detect the humidity value of the seedling production environment, intuitively reflects the actual water demand in the seedling raising process, and can be used for the seedling raising process. The micro-sprinkler irrigation amount and water demand are precisely controlled to ensure that the seedlings are provided with appropriate and sufficient water;

(2) The multi-level sensor can be connected with the control system. After the signal detected by the multi-level sensor is processed by the circuit of the control system and the single-chip microcomputer, it can automatically drive the micro-sprinkler sprinkler to work, and realize automatic control. Automated and large-scale production provides key technical support;

(3) By precisely controlling the amount of nozzles, the seedlings will not be impacted and damaged during the micro-spraying process.

Description of drawings

Figure 1 is a schematic diagram of the structure of a multi-level sensor;

Fig. 2 is the structural representation of micro-sprinkler irrigation nozzle;

Figure 3 is a system structure diagram of a precision micro-sprinkler irrigation system for greenhouse seedling raising.

In the picture: 1 insulator; 2 electrode; 3 steel column; 4 nozzle; 5 connecting water pipe; 6U spring.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar promotions without departing from the connotation of the present invention. Accordingly, the present invention is not limited by the specific embodiments disclosed below.

The method for controlling the precision of micro-sprinkler irrigation in greenhouse seedling raising according to the present invention includes the following steps.

The first step is to establish a crop growth cycle model according to the humidity and water demand required by different crop growth cycles, and perform multi-pole combinations on the electrodes on the multi-pole sensor.

The multi-pole sensor includes a cylindrical insulator 1 and a plurality of electrodes 2 arranged in the axial direction in the insulator 1. The electrodes 2 are arranged at intervals in the insulator 1, and the distances between the electrodes 2 are not equal. 2-12mm. One end of the electrode 2 is exposed to the outer end of the insulator, and the other end of the electrode 2 is located in the insulator 1, and an analog resistor is connected between every two electrodes 2. Therefore, any combination of two electrodes in the above-mentioned multiple electrodes 2 can form a Group electrode sensor.

The distance between the two working electrodes 2 in the multi-pole sensor is relatively small, generally 2-8 mm. At this time, the electrode sensor including the above two working electrodes is used to measure the relative humidity around the seedling in the non-micro-sprinkling state. In the multi-pole sensor, the distance between the two electrodes involved in the work is relatively large, generally 6-12mm. At this time, the electrode sensor including the above two working electrodes is used to measure the water demand in the state of micro-sprinkler irrigation.

In this embodiment, as shown in FIG. 1 , the insulator 1 is provided with six electrodes 2 , and any electrodes of the six electrodes are combined in pairs to form fifteen groups of electrode sensors, and each group of electrode sensors can complete the non-sprinkling state Measurement of relative humidity or measurement of water demand in sprinkler irrigation. In this embodiment, fifteen kinds of crop growth cycle models are established by using the above fifteen groups of electrode sensors, as described below.

Model 1: In the early stage of crop growth, the humidity is the highest and the water demand is the largest;

Model 2: In the early stage of crop growth, the humidity is medium and high, and the water demand is medium and high;

Model 3: In the early stage of crop growth, the humidity is low and the water demand is low;

Model 4: In the early stage of crop growth, the humidity is the highest and the water demand is medium;

Model 5: In the early stage of crop growth, the humidity is medium and high, and the water demand is low;

Model 6: In the middle stage of crop growth, the humidity is very high and the water demand is large;

Model 7: In the middle stage of crop growth, the humidity is in the middle and the water demand is in the middle;

Model 8: In the middle stage of crop growth, the humidity is low and the water demand is very low;

Model 9: In the middle stage of crop growth, the humidity is very high and the water demand is medium;

Model 10: In the middle stage of crop growth, in the humidity, the water demand is very low;

Model 11: In the late stage of crop growth, the humidity is high and the water demand is large;

Model 12: In the late stage of crop growth, the humidity is medium and the water demand is medium and low;

Model 13: late crop growth, low humidity and low water demand;

Model 14: In the late stage of crop growth, the humidity is high and the water demand is medium;

Model 15: In the late stage of crop growth, the humidity is low, and the water demand is very low.

In the second step, according to the actual crop growth cycle model, turn on two electrodes with small distances in the multi-stage sensor, and use the multi-pole sensor to measure the relative humidity around the seedling in the non-micro-sprinkling state. When the relative humidity is lower than the set value , for example, when 66%, start the micro-sprinkler sprinkler.

During the working process, the two electrodes with a relatively small distance are switched on, so that the multi-pole sensor is in the relative humidity measurement state during non-micro-sprinkler irrigation, and the relative humidity around the seedling is measured. When the relative humidity value drops to 66-100%, Start the micro-sprinkler sprinkler. The calculation formula for relative humidity (%) measurement is

Among them, F is the relative humidity value; Y is the distance between the two electrodes with relatively small distance, the unit is mm; Z is the analog resistance value connecting the two working electrodes, the unit is KΩ.

The third step is to automatically switch the two working electrodes of the multi-level sensor while starting the micro-sprinkler sprinkler head, connect the two electrodes with a large distance in the multi-level sensor, and use the multi-pole sensor to measure the water demand in the micro-sprinkler irrigation state.

In the above step 2, when the relative humidity measured by the multi-pole sensor drops to the set value, the two working electrodes of the multi-pole sensor are automatically switched. At this time, the two electrodes with a relatively large distance are connected, and the relative humidity around the seedling is The humidity was measured, and the micro-sprinkler sprinkler was activated at the same time to perform micro-sprinkler irrigation on the seedlings. When the relative humidity value around the seedling detected by the multi-level sensor reaches 70-80%, the micro-sprinkler sprinkler head is turned off.

In the present invention, the water demand measurement of the micro-sprinkler irrigation state is realized by controlling the micro-sprinkler irrigation time. Assuming that the micro-sprinkler time of the micro-sprinkler irrigation nozzle is L, the calculation formula for the measurement of the micro-sprinkler time is:

L=-0.7424+1.3440X+22.1517/Z

Among them, the unit of L is s, X is the distance between the two working electrodes with relatively large distance, the unit is mm; Z is the analog resistance value connecting the two working electrodes, the unit is KΩ.

When the micro-sprinkler irrigation time of the micro-sprinkler sprinkler reaches the L value, the micro-sprinkler sprinkler will automatically close.

As shown in Figure 2, the micro-sprinkler sprinkler head includes a steel column 3, a nozzle 4, a connecting water pipe 5 and a U-shaped spring 6, the nozzle 4 is arranged in a vertical direction, a water spray hole is arranged in the nozzle 4, and the length of the nozzle 4 is 2- 4cm, the diameter of the water spray hole is 0.8-1.2mm. The nozzle 4 is connected to the water supply pipeline through the connecting water pipe 5 at the bottom thereof, a steel column 3 is arranged above the nozzle 4, and the top of the nozzle 4 is connected to the steel column 3 above it through a U-shaped spring 6. There is a certain pressure of flowing water in the water supply pipe. During the process of flowing through the water spray holes in the nozzle 4, the flowing water is turned into a fine mist spray. After being sprayed from the top of the water spray hole, it is directly sprayed to the steel column 3 above the nozzle. , the water droplets in the spray collide with the steel column 3 and are ejected outward. Since the upwardly sprayed spray has a faster flow rate, the upwardly sprayed spray will vibrate the U-shaped spring 6 connecting the nozzle 4 and the steel column 3 during the collision with the steel column 3, and the vibration of the U-shaped spring 6 is more conducive to the distribution of water droplets. , improve the scattering effect of water droplets, improve the spraying uniformity and spraying range of the nozzle; in addition, when the water droplets hit the U-shaped spring 6, the water droplets are further atomized by the vibration of the U-shaped spring 6, and there is no harm to the seedlings . The formula for calculating the diameter d of the spray hole is:

Among them, d is the diameter of the nozzle, the unit is mm; p is the injection pressure, the unit is bar; q is the injection flow, the unit is L/min; n is the number of nozzles; η is the nozzle efficiency coefficient, η=1.05-1.10.

Through the above formula, the diameter of the water spray hole of the nozzle is 0.8-1.2mm. When the diameter of the water spray hole is 0.8mm, the spray effect is the best, the spray water is uniform, and the water droplet density is reasonable.

The fourth step, after the micro-sprinkler irrigation is completed, automatically switch the two working electrodes of the multi-level sensor, turn on the two electrodes with a small distance in the multi-level sensor, and use the multi-pole sensor again to measure the relative humidity around the seedling in the non-micro-sprinkler state. Repeat steps 2 to 3 above.

The precision control method for seedling-raising micro-sprinkler irrigation described in the present application is realized by a seedling-raising precision micro-sprinkler irrigation system. The seedling-raising precision micro-sprinkler irrigation system includes a multi-pole sensor, a micro-sprinkler irrigation nozzle and a control mechanism. The sprinkler heads are connected, and the control mechanism adopts a control system based on single-chip microcomputer. In this embodiment, the single-chip microcomputer, the host computer connected by the communication interface, the multi-pole sensor and the micro-sprinkler sprinkler head form a large and medium-sized precision micro-sprinkler irrigation system. The single-chip microcomputer can use the model STC15 series MCU, other types of MCU can also be used. The single-chip microcomputer can not only be used to receive the signal of the multi-pole sensor, process it (that is, operate the lower computer through the touch screen), control the display and output, but also communicate with the upper computer to realize the micro-sprinkler irrigation control. Through the upper computer, you can not only set parameters and manage the running status, but also connect multiple lower computers at the same time for control, realizing long-distance, large-scale, and factory-like humanized centralized management, which is suitable for large-scale and factory-like management. The structure diagram of the system is shown in Figure 3.

In the actual use process, the upper computer is used for detection and control. When the humidity of the seedlings is within an appropriate range, the single-chip microcomputer is not triggered, and the micro-sprinkler sprinkler head does not spray water. As the humidity of the seedling raising environment decreases, when it drops to the set value, the single-chip microcomputer is triggered, and the micro-sprinkler sprinkler head performs micro-sprinkler irrigation. Since the humidity required for different seedlings is different, the related trigger values set are also different. At this time, the relevant parameters can be set through the host computer.

The precision control method of the micro-sprinkler irrigation for greenhouse seedling raising provided by the present invention has been introduced in detail above. The principles and implementations of the present invention are described herein by using specific examples, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The above description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (7)

1. A micro-sprinkling irrigation precision control method for greenhouse seedling cultivation is characterized by comprising the following steps:

s1, establishing a crop growth cycle model according to humidity and water demand required by different crop growth cycles, carrying out multi-electrode combination on electrodes of a multi-stage sensor, and finishing measurement of relative humidity in a non-sprinkling irrigation state or measurement of water demand in a sprinkling irrigation state by combining each group of electrodes:

the multistage sensor comprises a cylindrical insulator and a plurality of electrodes which are positioned in the insulator and are arranged along the axial direction, the electrodes are arranged in the insulator at intervals, the intervals among the electrodes are unequal, one ends of the electrodes are exposed at the outer end of the insulator, the other ends of the electrodes are positioned in the insulator, analog resistors are connected between any two electrodes of the electrodes, and the multistage sensor is placed in the space outside the soil;

s2, according to an actual crop growth period model, two electrodes with the distance of 2-8mm in the multi-stage sensor are connected, the relative humidity around the seedling is measured by the multi-stage sensor in a non-micro-sprinkling irrigation state, when the relative humidity is lower than a set value, the micro-sprinkling irrigation spray head is started, and the calculation formula of the relative humidity measurement is as follows

Wherein F is a relative humidity value, Y is a distance between the two working electrodes and has a unit of mm, and Z is a simulated resistance value connecting the two working electrodes and has a unit of K omega;

s3, when the micro-sprinkling irrigation nozzle is started, two working electrodes of the multi-stage sensor are automatically switched, two electrodes with the distance of 6-12mm in the multi-stage sensor are switched on, and the multi-stage sensor is utilized to measure the water demand in a micro-sprinkling irrigation state:

the water demand measurement of the micro-sprinkling irrigation state is realized by controlling the micro-sprinkling irrigation time, and the calculation formula of the micro-sprinkling time L of the micro-sprinkling irrigation spray head is

L＝-0.7424+1.3440X+22.1517/Z

The unit of L is s, X is the distance between the working electrodes and the unit is mm, Z is the simulated resistance value connecting the two working electrodes and the unit is K omega, and when the micro-sprinkling irrigation time of the micro-sprinkling irrigation nozzle reaches the L value, the micro-sprinkling irrigation nozzle is closed;

and S4, after the micro-sprinkling irrigation is finished, automatically switching two working electrodes of the multi-stage sensor, switching on the electrodes with the interval of 2-8mm in the multi-stage sensor, and repeating S2 and S3.

2. The precision control method of greenhouse seedling culture micro-sprinkling irrigation according to claim 1, wherein six electrodes are arranged in the insulator, and any two of the six electrodes are combined to form fifteen sets of electrode sensors.

3. The precise control method of micro-sprinkling irrigation for seedling raising in greenhouse as claimed in claim 1, wherein the micro-sprinkling irrigation nozzle comprises a steel column, a nozzle, a connecting water pipe and a U-shaped spring, the nozzle is vertically arranged, a water spray hole is arranged in the nozzle, the length of the nozzle is 2-4cm, the nozzle is connected with a water supply pipeline through a connecting water pipe at the bottom of the nozzle, the steel column is arranged above the nozzle, the top of the nozzle is connected with the steel column above the nozzle through the U-shaped spring, and the calculation formula of the diameter d of the water spray hole is that

Wherein d is the diameter of the nozzle, and the unit is mm, p is the injection pressure, and the unit is bar, q is the injection flow, and the unit is L/min, n is the number of the nozzles, eta is the efficiency coefficient of the nozzle, and eta is 1.05-1.10.

4. The micro-sprinkling irrigation precision control method for seedling raising in greenhouses according to claim 3, wherein the diameter of a water spraying hole of the nozzle is 0.8-1.2 mm.

5. The micro-sprinkling irrigation precision control method for seedling raising in greenhouses according to claim 1, wherein the set value in S2 is 66% -100%.

6. The method for controlling the micro-sprinkling irrigation precision of the seedling growing in the greenhouse according to claim 1, wherein the control method is realized by a micro-sprinkling irrigation precision system of the seedling growing in the greenhouse, the micro-sprinkling irrigation precision system of the seedling growing in the greenhouse comprises a multi-stage sensor, a micro-sprinkling irrigation nozzle and a control mechanism, the control mechanism is respectively connected with the multi-stage sensor and the micro-sprinkling irrigation nozzle, and the control mechanism adopts a control system based on a single chip microcomputer.

7. The micro-sprinkling irrigation precision control method for seedling raising in greenhouses according to claim 6, wherein the single chip microcomputer is a single chip microcomputer of STC15 series.

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