CN105052688A - Irrigation control system suitable for greenhouse single crop - Google Patents

Abstract

The invention relates to an irrigation control system suitable for a greenhouse single crop. Hardware of the system comprises a control center, a Zigbee networking module, a detection module and an irrigation module, wherein the control center, the Zigbee networking module and the detection module are connected in sequence; and the control center, the Zigbee networking module and the irrigation module are connected in sequence. The whole irrigation control system is simple in structure, low in power consumption, short in time delay, large in network capacity and safe and reliable. The ZigBee technology is combined with a substrate moisture sensor, an illumination sensor, a temperature and humidity sensor, a greenhouse substrate cultured single crop root system dynamic growth model and a substrate moisture body dynamic change model, and mutual matching of a substrate moisture body and a crop root system is realized, so that, under the precondition of not influencing yield and quality of the crop, dynamic and real-time performances of greenhouse substrate cultured single crop moisture forecast are improved, water-saving irrigation is realized truly, and the system plays an important practical significance for realizing water-saving greenhouse single crop substrate culture.

Description

Be applicable to the irrigation control system of greenhouse individual plant crop

Technical field

The invention belongs to agricultural facility technical field of cultivation, be specifically related to a kind of irrigation control system being applicable to greenhouse individual plant crop.Relevant to agricultural engineering field.

Background technology

Current China facility soilless culture area increases year by year and is still in and flourish enters the impetus by force, and especially facility organic mass cultivation vegetables area accounts for more than 85% of the national soilless culture gross area, based on Production requirement amount greatly, not long keeping vegetables.Vegetables water requirement is large, and cultivation matrix has the water retention characteristic different from soil and water transport characteristics, therefore, how to realize the automation of facility substrate culture vegetable irrigation, how about according to the water properties Optimal Irrigation amount of matrix, to save agricultural irrigation water, improve water use efficiency, play high crop yield potentiality, to become in facilities horticulture development a problem in the urgent need to address.

Begun one's study the water-saving irrigation of substrate culture and the water-saving irrigation system of development facility substrate culture both at home and abroad, but up to the present, although corresponding research has obtained certain progress, but still be in the experimental study stage, be difficult to the water-saving irrigation realizing real substrate culture, still have suitable distance from practical.Therefore, the control method of irrigation of research facilities substrate culture and device to realize substrate culture intellectuality, precision is irrigated has important theory value and realistic meaning.

Summary of the invention

The object of the invention is to the shortcoming and defect overcoming the existence of existing agricultural facility culture technique, provide a kind of irrigation control system being applicable to greenhouse individual plant crop, this system can be used in the accurate water-saving irrigation of substrate in greenhouse cultivation individual plant crop.

The object of the present invention is achieved like this:

Computer technology and Zigbee Radio Transmission Technology is used to match, crop root model and culture substrate moisture transport model is set up by a series of Dynamic Data Processing, and the degree of overlapping of decision model, to realize the accurate water-saving irrigation of substrate in greenhouse cultivation individual plant crop, namely relatively judge current the need of irrigation according to the moisture content lower limit of water supply in media sensor current detection substrate water content and setting, the crop root distributed model based on accumulated temperature is set up according to temperature sensor data, culture substrate moisture transport model is set up according to great number tested data, theoretical irrigation volume is calculated according to temperature and moisture sensors data, last according to an arrow flow and dropper and calculate each actual irrigation amount, with the volume degree of overlapping of crop root zone and wetting body, the theoretical irrigation volume calculated and actual irrigation amount judge that current whether stopping is irrigated.

Particularly, technical scheme of the present invention is as follows:

A kind of irrigation control system being applicable to greenhouse individual plant crop:

Comprise control centre (100), Zigbee networking module (200), detection module (300) and irrigate module (400);

Control centre (100), Zigbee networking module (200), detection module (300) connect successively;

Control centre (100), Zigbee networking module (200), irrigation module (400) connect successively;

Described control centre (100) comprises host computer (110) and power supply (120);

Host computer (110) is electrically connected with power supply (120).

Power supply (120) is respectively water supply in media sensor (310), air temperature sensor (320), optical sensor (330), air humidity sensor (340) and magnetic valve (410) and provides power supply, and host computer (110) can directly be connected 220V alternating current with gateway (210).Host computer (110) receives detection module (300) information, and carries out data analysis and storage, determines that whether opening magnetic valve (410) irrigates according to the irrigation method preset.

Described Zigbee networking module (200) comprises gateway (210), ZigBee data acquisition module (220), ZigBee control module (230);

Gateway (210) is connected with ZigBee data acquisition module (220), ZigBee control module (230) respectively.

After connecting host computer (110) and gateway (210), open IE browser, input gateway IP, log in gateway (210) interface, correct gateway (210) system time, then ZigBee data acquisition module (220) and ZigBee control module (230) power on, net is driven at the network configuration mid point at gateway (210) interface, enter node mapping table, carry out device address, the device name of setting ZigBee data acquisition module (220) and ZigBee control module (230) and go offline the time.Whether gateway (210) needs the state of detection module in Sampling network (300), comprise online, data upload interval etc.

Described detection module (300) comprises water supply in media sensor (310), air temperature sensor (320), optical sensor (330), air humidity sensor (340);

Water supply in media sensor (310), air temperature sensor (320), optical sensor (330), air humidity sensor (340) are connected with ZigBee data acquisition module (220) respectively, ZigBee data acquisition module (220), with the acquisition interval Information Monitoring set, is sent to gateway (210) by LAN and is uploaded to host computer (110).

Described irrigation module (400) comprises magnetic valve (410), drips arrow (420), pipeline (430) and water pump (440);

Magnetic valve (410), water pump (440) are connected with ZigBee control module (230); Magnetic valve (410) is arranged on pipeline (430) and is above communicated with water pump (440).

When host computer (110) begins to irrigate order to ZigBee control module (230) by spreading under gateway (210), first open magnetic valve (410), after open water pump (440), by drip an arrow (420) irrigate; When lower biography stops irrigating order to ZigBee control module (230), first switch off the pump (440), rear shut electromagnetic valve (410).

Have automatic network-building function after described system electrification, the external network be connected with control centre (100) is WLAN.That is, control centre (100) forms WLAN by gateway.

Be applicable to a control method of irrigation for greenhouse individual plant crop, described control method comprises the following steps:

1. selected cultivation matrix kind, determines the volume ratio of various matrix;

2. dimensionless analysis is adopted, under utilizing different drip irrigation flow, different water supply time and an arrow different buried depth situation, wetting body top layer horizontal infiltration Distance geometry Vertical Infiltration distance sets up wetting body characteristic model, and sets up wetting body section model and wetting body volume-based model on this basis;

3. adopt Method for Numerical, utilize under the best growing condition, the root system radius that the root of crop different growing stages is dark and corresponding sets up crop root zone section model and crop root zone volume-based model;

4. compare with setting moisture content lower limit according to water supply in media sensor current detection substrate water content, judge whether to need to irrigate, according to the volume degree of overlapping of crop root zone and wetting body and the theoretical irrigation volume, the actual irrigation amount that calculate, system judges whether to stop irrigating;

System stops control method of irrigation as follows:

Control centre (100) detects data according to detection module (300) and calculates crop root zone volume-based model, send and irrigate instruction to irrigating module (400) and timing, when reaching irrigation during sensor assay intervals integral multiple, calculate matrix wetting body volume-based model, the volume of go forward side by side row crop root district and wetting body and volume Overlapping Calculation;

Detect data according to detection module (300), utilize Penman formula to calculate Crop Evapotranspiration ET ₀, according to crop coefficient K _c, moisture adjusted coefficient K _Θand ET ₀calculate actual evapotranspiration (i.e. theoretical irrigation volume) ET, last according to the irrigation flow set and irrigation and calculate actual irrigation amount, if theoretical irrigation volume is equal with actual irrigation, but the volume degree of overlapping of crop root and wetting body does not meet the demands, although illustrate that irrigation volume meets the demands in theory, irrigation water, not whole district's distribution, needs to continue to irrigate, until stop when degree of overlapping meets the demands irrigating, record residue irrigation volume (that is: theoretical irrigation volume-actual irrigation amount); If the theoretical irrigation volume of actual irrigation amount <, but the volume degree of overlapping of crop root and wetting body meets the demands, illustrate that irrigation water in crop root zone distribution better, stops irrigating and record residue irrigation volume (that is: theoretical irrigation volume-actual irrigation amount); Calculate the accumulative residue irrigation volume (that is: the residue irrigation volume sum of irrigation frequency occurring in a day) of a day, if accumulative residue irrigation volume is negative, then system is normally run; If accumulative residue irrigation volume is positive number, then accumulative residue irrigation volume is irrigated sunrise in second day for first 1 hour, make full use of the Optimum Irrigation time before sunrise;

System software controls main-process stream (see Fig. 3) of the present invention is as described below:

1. start;

2. system initialization;

3. LAN is set up;

4. Zigbee networking module, detection module and irrigation module is allowed to add network;

5. detection module Information Monitoring;

6. control centre is uploaded in Information Monitoring;

7. control centre analyzes, processes the information uploaded;

8. control centre judges whether to irrigate;

9. control command is passed under control centre to irrigating module;

10. irrigate module and perform control command;

Major advantage of the present invention is as follows:

(1) consider the Water Transport situation of Crop Evapotranspiration, crop root growth and cultivation matrix (volume ratio, vinegar grain: vermiculite: perlite=2:1:1), better realize water saving than normal irrigation operation.

(2) according to crop root zone and cultivation matrix (volume ratio, vinegar grain: vermiculite: perlite=2:1:1) overlapping cases of wetting body volume, and whether irrigated by the actual evapotranspiration decision-making that Penman formula calculates, improve dynamic, the real-time of substrate in greenhouse cultivation individual plant crop water forecast.

Test proves of the present invention reasonable in design feasible, easy and simple to handle, and successful, may be used on, in the irrigation control of individual plant crop or other crops, having a good promotion prospects.

Accompanying drawing explanation

Fig. 1: system architecture block diagram of the present invention.

Fig. 2: Systematical control schematic diagram of the present invention.

Fig. 3: software flow figure of the present invention.

Description of reference numerals:

100-control centre

110-host computer, 120-power supply;

200-Zigbee networking module

210-gateway, 220-ZigBee data acquisition module, 230-ZigBee control module;

300-detection module

310-water supply in media sensor, 320-air temperature sensor, 330-optical sensor, 340-air humidity sensor;

400-irrigate module

410-magnetic valve, 420-drip arrow, 430-pipeline, 440-water pump.

Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is further described.Following examples for illustration of the present invention, but are not used for limiting the scope of the invention.

Embodiment 1

As shown in Figure 1, applicant devises a kind of irrigation control system being applicable to greenhouse individual plant crop, and it comprises control centre (100), Zigbee networking module (200), detection module (300) and irrigates module (400);

Control centre (100), Zigbee networking module (200), detection module (300) connect successively;

Control centre (100), Zigbee networking module (200), irrigation module (400) connect successively;

Described control centre (100) comprises host computer (110), power supply (120);

Host computer (110) is electrically connected with power supply (120).

Power supply (120) is respectively water supply in media sensor (310), air temperature sensor (320), optical sensor (330), air humidity sensor (340) and magnetic valve (410) and provides power supply, and host computer (110) can directly be connected 220V alternating current with gateway (210).Host computer (110) receives detection module (300) information, and carries out data analysis and storage, automatically sends instruction determine that whether opening magnetic valve (410) irrigates according to the irrigation system preset.

Described Zigbee networking module (200) comprises gateway (210), ZigBee data acquisition module (220), ZigBee control module (230).

Gateway (210) is connected with ZigBee data acquisition module (220), ZigBee control module (230) respectively.

After connecting host computer (110) and gateway (210), open IE browser, input gateway IP, log in gateway (210) interface, correct gateway (210) system time, then ZigBee data acquisition module (220) and ZigBee control module (230) power on, net is driven at the network configuration mid point at gateway (210) interface, enter node mapping table, carry out device address, the device name of setting ZigBee data acquisition module (220) and ZigBee control module (230) and go offline the time.Whether gateway (210) needs the state of detection module in Sampling network (300), comprise online, data upload interval etc.

Described detection module (300) comprises water supply in media sensor (310), air temperature sensor (320), optical sensor (330), air humidity sensor (340);

Water supply in media sensor (310), air temperature sensor (320), optical sensor (330), air humidity sensor (340) are connected with ZigBee data acquisition module (220) respectively, ZigBee data acquisition module (220), with the acquisition interval Information Monitoring set, is sent to gateway (210) by LAN and is uploaded to host computer (110).

Described irrigation module (400) comprises magnetic valve (410), drips arrow (420), pipeline (430) and water pump (440);

Magnetic valve (410) is connected with ZigBee control module (230) with water pump (440), magnetic valve (410) is arranged on pipeline (430), when host computer (110) begins to irrigate order to ZigBee control module (230) by spreading under gateway (210), first open magnetic valve (410), after open water pump (440), by drip an arrow (420) irrigate; When lower biography stops irrigating order to ZigBee control module (230), first switch off the pump (440), rear shut electromagnetic valve (410).

Have automatic network-building function after described system electrification, namely control centre (100) forms WLAN by gateway.

The software flow figure of the present embodiment is see Fig. 3, and Systematical control schematic diagram is see Fig. 2.

The KL-H1100 wireless data gateway that Zigbee networking module (200) in the present embodiment adopts the Kunlun, Beijing seashore sensor Co., Ltd to produce, the model of wireless data acquisition module are JZH-3 series, wireless module is JZH-2 series; 5TE water content detection sensor, EHT temperature sensor and humidity sensor that detection module (300) adopts Decagon company of the U.S. to produce and PYR optical sensor.

The type selecting of equipment that applicant provides in the present embodiment just illustrates embodiments of the invention, but is not limited thereto for enforcement of the present invention.

Embodiment 2

Applicant utilizes system described in embodiment 1 to establish a kind of method of irrigation control of the irrigation control system based on greenhouse individual plant crop, and the concrete steps of the inventive method are as follows:

1. selected cultivation matrix kind, determines the volume ratio of various matrix;

Selected matrix is vinegar grain, vermiculite and perlite, and volume ratio is 2:1:1.

2. dimensionless analysis is adopted, under utilizing different drip irrigation flow, different water supply time and an arrow different buried depth situation, wetting body top layer horizontal infiltration Distance geometry Vertical Infiltration distance sets up wetting body characteristic model, and sets up wetting body section model and wetting body volume-based model on this basis;

Computing formula is as follows:

$W=A_1{\left(qt\right)}^{n_1}{\left(\frac{Ks\mathrm{\&theta;}}{qz}\right)}^{(n_1-\frac{1}{3})}---\left(1\right)$

In formula: W: wetting body top layer horizontal infiltration distance, unit: cm; Ks: saturated hydraulic conductivity, unit: cm/s; θ: initial aqueous rate, unit: cm ³cm ^-3; Q: drip irrigation flow, unit: L/h; Z: drip arrow and imbed the matrix degree of depth, unit: cm; T: drip irrigation time, unit: min; A ₁, n ₁: treat fitting parameter;

Wetting body Vertical Infiltration distance model is:

$D=A_2{\left(qt\right)}^{n_2}{\left(\frac{Ks\mathrm{\&theta;}}{qz}\right)}^{(n_2-\frac{1}{3})}---\left(2\right)$

In formula: D: wetting body Vertical Infiltration distance, unit: cm; A ₂, n ₂: treat fitting parameter;

Wetting body section model is:

y＝ax ²+b(3)

In formula: y: drip irrigation point to wetting body Vertical Infiltration distance, unit: cm; A, b: equation coefficient;

Wetting body volume-based model is:

$V_S=\underset{0}{\overset{D}{\&Integral;}}{\mathrm{\&pi;x}}^{2}dy---\left(4\right)$

In formula: Vs: wetting body volume, unit: cm ³;

3. adopt Method for Numerical, utilize under the best growing condition, the root system radius that the root of crop different growing stages is dark and corresponding sets up crop root zone section model and crop root zone volume-based model;

Computing formula is as follows:

Crop root zone section model is:

R＝Cz ³+Dz ²+Ez+F(5)

In formula: R: cross sectional boundary line arbitrfary point, root district to the distance of main root, unit: cm; The root that z:R is not corresponding is dark, unit: cm; : C, D, E, F: the parameter relevant with effective accumulated temperature, can be expressed as:

C＝C ₁DD ³+C ₂DD ²+C ₃DD+C ₄

D＝D ₁DD ³+D ₂DD ²+D ₃DD+D ₄

E＝E ₁DD ³+E ₂DD ²+E ₃DD+E ₄(6)

F＝F ₁DD ³+F ₂DD ²+F ₃DD+F ₄

In formula: C ₁, C ₂, C ₃, C ₄, D ₁, D ₂, D ₃, D ₄, E ₁, E ₂, E ₃, E ₄, F ₁, F ₂, F ₃, F ₄: treat fitting parameter; Wherein, DD is effective accumulated temperature, and its accounting equation is:

$DD=\&Sigma;T=\left\{\begin{array}{c}0;T_b\&GreaterEqual;T_a\\ T_a-T_b;T_b\&le;T_a<T_m\\ T_m-T_b;T_a\&GreaterEqual;T_m\end{array}\right\}---\left(7\right)$

In formula: T _a: daily mean temperature, unit: DEG C; T _b: Crop development lower limit temperature, unit: DEG C; T _m: Crop development ceiling temperature, unit: DEG C;

Crop root zone section volume-based model is:

$V_R=\underset{0}{\overset{Z_{\max }}{\&Integral;}}{\mathrm{\&pi;R}}^{2}dz---\left(8\right)$

In formula: V _r: crop root zone volume, unit: cm ³; Z _max: crop root depth capacity, unit: cm; Can be expressed as:

Z _max＝z ₀+gDD(9)

In formula: z ₀: during crop field planting, root is dark, unit: cm; G: treat fitting parameter; DD is effective accumulated temperature, unit: DEG C;

4. compare with setting moisture content lower limit according to water supply in media sensor current detection substrate water content, judge whether to need to irrigate, judge whether to stop irrigating according to the theoretical irrigation volume of the volume degree of overlapping of crop root zone and wetting body and calculating, actual irrigation amount;

System stops control method of irrigation as follows:

Control centre (100) detects data according to detection module (300) and calculates crop root zone volume-based model, send and irrigate instruction to irrigating module (400) and timing, when reaching irrigation during sensor assay intervals integral multiple, calculate matrix wetting body volume-based model, the volume of go forward side by side row crop root district and wetting body and volume Overlapping Calculation;

Detect data according to detection module (300), utilize Penman formula to calculate Crop Evapotranspiration ET ₀, according to crop coefficient K _c, moisture adjusted coefficient K _Θand ET ₀calculate actual evapotranspiration (i.e. theoretical irrigation volume) ET, last according to the irrigation flow set and irrigation and calculate actual irrigation amount, if theoretical irrigation volume is equal with actual irrigation, but the volume degree of overlapping of crop root and wetting body does not meet the demands, although illustrate that irrigation volume meets the demands in theory, irrigation water, not whole district's distribution, needs to continue to irrigate, until stop when degree of overlapping meets the demands irrigating, record residue irrigation volume (that is: theoretical irrigation volume-actual irrigation amount); If the theoretical irrigation volume of actual irrigation amount <, but the volume degree of overlapping of crop root and wetting body meets the demands, illustrate that irrigation water in crop root zone distribution better, stops irrigating and record residue irrigation volume (that is: theoretical irrigation volume-actual irrigation amount); Calculate the accumulative residue irrigation volume (that is: the residue irrigation volume sum of irrigation frequency occurring in a day) of a day, if accumulative residue irrigation volume is negative, then system is normally run; If accumulative residue irrigation volume is positive number, then accumulative residue irrigation volume is irrigated sunrise in second day for first 1 hour, make full use of the Optimum Irrigation time before sunrise;

Computing formula is as follows:

Volume degree of overlapping can be expressed as:

$overlap(root,wetting-body)=\frac{\begin{array}{cc}overlap& \mathrm{\&alpha;}(root,wetting-body)\end{array}}{V_R}\&times;100\%---\left(10\right)$

In formula: overlap (root, wetting-body): the degree of overlapping of root system and wetting body, unit: %; Overlapa (root, wetting-body): the overlapping volume of root system and wetting body, unit: cm ³; V _r: root system volume, unit: cm ³;

The overlapping volume of root system and wetting body is namely: plane based on stromal surface, with crop root base portion for the origin of coordinates, crop root volume is crossing with wetting body volume, the lap of formation.Lap is the intersecting point coordinate that formula (4) and (8) calculate by formula (3) and (5), segmentation calculate revolution volume add and minimum of a value.That is:

$\begin{array}{cc}overlap& \mathrm{\&alpha;}(root,wetting-body)=\min \underset{k=1}{\overset{m}{\&Sigma;}}(V_1+V_2+\mathrm{...}+V_{k+1})---\left(11\right)\end{array}$

In formula: m: root system and wetting body section intersection point number, unit: individual; V _k: segmentation revolution volume, unit: cm ³, k=1,2 ... m;

Segmentation revolution volume V _kdivide the revolution volume V of root system _rkwith the revolution volume V of wetting body _sk, be expressed as:

$V_{Rk}=\underset{m_{k-1}}{\overset{m_k}{\&Integral;}}{\mathrm{\&pi;R}}^{2}dz---\left(12\right)$

In formula: m _k: root system and wetting body section model intersection point ordinate, can be tried to achieve by formula (3) and (5) Simultaneous Equations, m ₀=0, m ₁m _k=Z _max;

$V_{Sk}=\underset{m_{k-1}}{\overset{m_k}{\&Integral;}}{\mathrm{\&pi;x}}^{2}dy---\left(13\right)$

In formula: m _k: root system and wetting body section model intersection point ordinate, can be tried to achieve by formula (3) and (5) Simultaneous Equations, m ₀=0, m ₁m _k=D;

If do not have intersection point after calculating, then overlapping volume can be expressed as:

overlapα(root,wetting-body)＝V _S(14)

Or overlap α (root, wetting-body)=V _r(15)

The result of calculation of getting formula (10) is less than overlapping volume when 1.

(2) actual evapotranspiration (i.e. theoretical irrigation volume) can be expressed as:

ET＝K _c*K _q*ET ₀(16)

Wherein:

$K_{\mathrm{\&theta;}}\left\{\frac{\mathrm{\&theta;}-{\mathrm{\&theta;}}_{wp}}{{\mathrm{\&theta;}}_c-{\mathrm{\&theta;}}_{wp}}\right\}/\ln 101---\left(17\right)$

${\mathrm{ET}}_0=\frac{0.408\mathrm{\&Delta;}(R_n-G)+r\frac{1713}{T+273}(e_s-e_a)}{\mathrm{\&Delta;}+1.64r}---\left(18\right)$

In formula: K _Θ: moisture correction factor; θ _c: field capacity, unit: cm ³cm ^-3; θ _wp: wilting coefficient water content, unit: cm ³cm ^-3; θ: sensor detects water content, unit: cm ³cm ^-3; ET ₀: reference crop unit interval transpiration rate, unit: mm; T: unit interval mean temperature, unit: DEG C; R _n: unit interval net radiation amount, unit: MJm ^-2; G: unit interval heat flux, unit: MJm ^-2; e _s: saturation vapour pressure, unit: KPa; e _a: actual water vapor pressure, unit: KPa; △: saturation vapour pressure and temperature curve slope, unit: KPa DEG C ^-1; R: psychrometer constant, unit: KPa DEG C ^-1; Wherein:

$e_s=0.6107\exp \frac{17.4T}{239+T}---\left(19\right)$

$\mathrm{\&Delta;}=4158.6e_s\frac{T}{{(T+239)}^2}---\left(20\right)$

$e_a=es\&times;\frac{RH}{100}=0.6107\exp \frac{17.4T}{239+T}---\left(21\right)$

r＝0.6455+0.00064T(22)

R _n＝2.441L-9.229(23)

G=0.1R _ndaytime (24)

G=0.5R _nnight (25)

RH in formula: relative air humidity, unit: %, can by humidity sensor measuring; L: unit interval illuminance, unit: klux;

Embodiment 3 systematic difference citing (for automatic irrigation substrate culture romaine lettuce in greenhouse)

Native system selects visualstudio as host computer interface program development tools, adopts the c# Programming with Pascal Language under .net, adopts sqlserver as background data base.

(1) test material

Select matrix be composite matrix (vinegar grain: vermiculite: perlite by volume=2:1:1), select crop to be romaine lettuce.

(2) system control model

Selected composite matrix (vinegar grain: vermiculite: perlite volume ratio=2:1:1) saturated hydraulic conductivity K _s=0.047cm/s, arranges and drips arrow dripping end flow q=0.15L/h, q=0.35L/h, q=0.5L/h; Composite matrix initial aqueous rate θ=0.18cm is set ³cm ^-3, θ=0.23cm ³cm ^-3, θ=0.29cm ³cm ^-3; Irrigation time t=5min, t=10min, t=20min, t=30min, t=40min, t=50min and t=60min are set; Arrange and drip arrow depth of burying z=3cm; Under utilizing different dripping end flow, different substrates initial aqueous rate and different drip irrigation to last condition, test data carries out matching, obtains parameter A ₁, A ₂and n ₁, n ₂be respectively 0.615,2.889 and 0.495,0.279, then composite matrix (vinegar grain: vermiculite: perlite volume ratio=2:1:1) wetting body top layer horizontal infiltration distance model is:

$W=0.615{\left(qt\right)}^{0.495}{\left(\frac{0.047\mathrm{\&theta;}}{3q}\right)}^{0.162}---\left(26\right)$

In formula: W: wetting body top layer horizontal infiltration distance, unit: cm; θ: initial aqueous rate, unit: cm ³cm ^-3; Q: drip irrigation flow, unit: L/h; T: drip irrigation time, min;

Wetting body Vertical Infiltration distance model is:

$D=2.889{\left(qt\right)}^{0.279}{\left(\frac{0.047\mathrm{\&theta;}}{3q}\right)}^{-0.054}---\left(27\right)$

In formula: D: wetting body Vertical Infiltration distance;

Wetting body section model is:

$y=-7.64{\left(qt\right)}^{-0.711}{\left(\frac{0.047\mathrm{\&theta;}}{3q}\right)}^{-0.378}---\left(28\right)$

In formula: y: drip irrigation point to wetting body Vertical Infiltration distance, unit: cm; A, b: equation coefficient;

Wetting body volume-based model is:

$V_S=\underset{0}{\overset{D}{\&Integral;}}{\mathrm{\&pi;x}}^{2}dy---\left(29\right)$

(2) Method for Numerical is utilized to set up crop root zone section model and volume-based model to the root system radius that composite matrix (volume ratio, vinegar grain: vermiculite: perlite=2:1:1) cultivates the root of romaine lettuce different growing stages dark and corresponding.Crop root zone section model is:

R＝Cz ³+Dz ²+Ez+F(30)

In formula: R: cross sectional boundary line arbitrfary point, root district to the distance of main root, unit: cm; The root that z:R is not corresponding is dark, unit: cm; : C, D, E, F: the parameter relevant with effective accumulated temperature, can utilize C when at every turn getting romaine lettuce root system sample, and D, E, F and accumulative effective accumulated temperature carry out data fitting acquisition, are expressed as:

C＝5.036×10 ^-10DD ³-5.656×10 ^-7DD ²+4.244×10 ^-5DD+7.599×10 ^-2

D＝-1.126×10 ^-8DD ³+1.483×10 ^-5DD ²-4.484×10 ^-3DD-0.503

E＝4.686×10 ^-8DD ³-7.259×10 ^-5DD ²+2.975×10 ^-2DD-0.359

F＝-2.673×10 ^-8DD ³+3.577×10 ^-5DD ²-9.952×10 ^-3DD-0.459(31)

In formula: DD is effective accumulated temperature, and its accounting equation is:

$DD=\mathrm{\&Sigma;}T=\left\{\begin{array}{c}0;T_b\&GreaterEqual;T_a\\ T_a-T_b;T_b\&le;T_a<T_m\\ T_m-T_b;T_a\&GreaterEqual;T_m\end{array}\right\}---\left(32\right)$

In formula: T _a: daily mean temperature, unit: DEG C; T _b: Crop development lower limit temperature, unit: DEG C; T _m: Crop development ceiling temperature, unit: DEG C;

Crop root zone volume-based model is:

$V_R=\underset{0}{\overset{Z_{\max }}{\&Integral;}}{\mathrm{\&pi;R}}^{2}dz---\left(33\right)$

In formula: V _r: crop root zone volume, unit: cm ³; Z _max: crop root depth capacity, unit: cm; Can be expressed as:

Z _max＝3+0.014DD(34)

Volume degree of overlapping can be shown:

$overlap(root,wetting-body)=\frac{\begin{array}{cc}overlap& \mathrm{\&alpha;}(root,wetting-body)\end{array}}{V_R}\&times;100\%---\left(35\right)$

In formula: overlap (root, wetting-body): the degree of overlapping of root system and wetting body, unit: %; Overlapa (root, wetting-body): the overlapping volume of root system and wetting body, unit: cm ³; V _r: root system volume, unit: cm ³;

The overlapping volume of root system and wetting body is namely: plane based on stromal surface, with crop root base portion for the origin of coordinates, crop root volume is crossing with wetting body volume, the lap of formation.Lap is the intersecting point coordinate that formula (29) and (33) calculate by formula (28) and (30), segmentation calculate revolution volume add and minimum of a value.That is:

$\begin{array}{cc}overlap& \mathrm{\&alpha;}(root,wetting-body)=\min \underset{k=1}{\overset{m}{\&Sigma;}}\end{array}(V_1+V_2+\mathrm{...}+V_{k+1})---\left(36\right)$

In formula: m: root system and wetting body section intersection point number, unit: individual; V _k: segmentation revolution volume, unit: cm ³, k=1,2 ... m;

Segmentation revolution volume V _kby the revolution volume V of root system _rkwith the revolution volume V of wetting body _skcomposition, is expressed as:

$V_{Rk}=\underset{m_{k-1}}{\overset{m_k}{\&Integral;}}{\mathrm{\&pi;R}}^{2}dz---\left(37\right)$

In formula: m _k: root system and wetting body section model intersection point ordinate, can be tried to achieve by formula (3) and (5) Simultaneous Equations, m ₀=0, m ₁m _k=Z _max;

$V_{Sk}=\underset{m_{k-1}}{\overset{m_k}{\&Integral;}}{\mathrm{\&pi;x}}^{2}dy---\left(38\right)$

In formula: m _k: root system and wetting body section model intersection point ordinate, can be tried to achieve by formula (3) and (5) Simultaneous Equations, m ₀=0, m ₁m _k=D;

If do not have intersection point after calculating, then overlapping volume can be expressed as:

overlapα(root,wetting-body)＝V _S(39)

Or overlap α (root, wetting-body)=V _r(40)

The result of calculation of getting formula (35) is less than overlapping volume when 1.

Actual evapotranspiration (i.e. theoretical irrigation volume) can be expressed as:

ET＝K _c*K _θ*ET ₀(41)

Wherein:

$K_{\mathrm{\&theta;}}=ln\{\frac{\mathrm{\&theta;}-{\mathrm{\&theta;}}_{wp}}{{\mathrm{\&theta;}}_c-{\mathrm{\&theta;}}_{wp}}+1\}/ln101---\left(42\right)$

${\mathrm{ET}}_0=\frac{0.408\mathrm{\&Delta;}(R_n-G)+r\frac{1713}{T+273}(e_s-e_a)}{\mathrm{\&Delta;}+1.64r}---\left(43\right)$

In formula: K _Θ: moisture correction factor; θ _c: field capacity, unit: cm ³cm ^-3; θ _wp: wilting coefficient water content, unit: cm ³cm ^-3; θ: sensor detects water content, unit: cm ³cm ^-3; ET ₀: reference crop unit interval transpiration rate, unit: mm; T: unit interval mean temperature, unit: DEG C; R _n: unit interval net radiation amount, unit: MJm ^-2; G: unit interval heat flux, unit: MJm ^-2; e _s: saturation vapour pressure, unit: KPa; e _a: actual water vapor pressure, unit: KPa; △: saturation vapour pressure and temperature curve slope, unit: KPa DEG C ^-1; R: psychrometer constant, unit: KPa DEG C ^-1; Wherein:

$e_s=0.6107\exp \frac{17.4T}{239+T}---\left(44\right)$

$\mathrm{\&Delta;}=4158.6e_s\frac{T}{{(T+239)}^2}---\left(45\right)$

$e_a=es\&times;\frac{RH}{100}=0.6107\exp \frac{17.4T}{239+T}---\left(46\right)$

r＝0.6455+0.00064T(47)

R _n＝2.441L-9.229(48)

G=0.1R _ndaytime (49)

G=0.5R _nnight (50)

RH in formula: relative air humidity, unit: %, can by humidity sensor measuring; L: unit interval illuminance, unit: klux;

(3) system control scheme

Be composite matrix (vinegar grain: vermiculite: perlite volume ratio=2:1:1) by upper computer selecting cultivation matrix, raise crop is romaine lettuce, and ceiling temperature T grown by setting romaine lettuce _m=40 DEG C, grow lower limit temperature T _b=5 DEG C, romaine lettuce root dark z during field planting ₀=3cm, setting romaine lettuce crop coefficient K _c=0.8 ~ 1, setting irrigate start and at the end of the volumetric water content of composite matrix (vinegar grain: vermiculite: perlite volume ratio=2:1:1) be respectively 16% and 35%, setting matrix field capacity θ _c=25%, setting romaine lettuce wilting coefficient moisture content θ _wp=10.4%, drip irrigation flow q=0.35L/h, within when not irrigating every 1 hour, gather a substrate water content and temperature, air themperature and humidity, intensity of illumination, within during irrigation every 2 minutes, gather once, and the drip irrigation time is kept in data storage.The matrix initial aqueous rate (θ) that 5TE sensor gathers by host computer and drip irrigation flow (q) arranged substitute into formula (26) with drip irrigation time (t) in data storage, (27), (28) and (29) obtain the wetting body model of composite matrix (vinegar grain: vermiculite: perlite volume ratio=2:1:1), the temperature utilizing temperature sensor to detect calculates effective accumulated temperature DD by formula (32), and substitute into formula (31), parameter in computing formula (30), substitute into formula (30), (33) and formula (34) obtain root model and the dark model of romaine lettuce maximum root of substrate culture romaine lettuce.Formula (37) is substituted into the segmentation revolution volume of (38) trying to achieve and bring formula (36) into, obtain the overlapping volume of romaine lettuce root system and matrix wetting body, and press formula (35) calculating volume degree of overlapping, the temp. and humidity that the intensity of illumination simultaneously detected by optical sensor, Temperature Humidity Sensor detect substitutes into formula (44) to formula (50), then the parameter calculated is substituted into formula (43) calculating romaine lettuce evapotranspiration ET ₀, by romaine lettuce evapotranspiration ET ₀with the moisture adjusted coefficient K that formula (42) calculates _Θbring formula (41) into, calculate actual evapotranspiration (that is: theoretical irrigation volume).When composite matrix (vinegar grain: vermiculite: perlite volume ratio=2:1:1) the wetting body water content that 5TE water supply in media sensor detects lower than 16% time, host computer sends instruction by gateway to ZigBee control module and magnetic valve, starts to irrigate; When romaine lettuce root system and matrix wetting body volume degree of overlapping are greater than 90%, host computer sends instruction to control module, closed electromagnetic valve, stops irrigating, and record residue irrigation volume (that is: the amount of theoretical irrigation volume-actual irrigation amount); If the theoretical irrigation volume of actual irrigation amount <, but the volume degree of overlapping of crop root and wetting body meets the demands, illustrate that irrigation water in crop root zone distribution better, stops irrigating and record residue irrigation volume (that is: the amount of theoretical irrigation volume-actual irrigation amount); Calculate the accumulative residue irrigation volume (that is: the residue irrigation volume sum of irrigation frequency occurring in a day) of a day, if accumulative residue irrigation volume is negative, then system is normally run; If accumulative residue irrigation volume is positive number, then accumulative residue irrigation volume is carried out irrigation volume in first 1 hour sunrise in second day, make full use of the Optimum Irrigation time before sunrise.

A kind of irrigation control system and method being applicable to greenhouse individual plant crop of the present invention's research and development, a whole set of irrigation system structure is simple, low-power consumption, cost is low, time delay is short, network capacity is large and safe and reliable, strong adaptability.The present invention is by ZigBee technology and water supply in media sensor, optical sensor and Temperature Humidity Sensor and substrate in greenhouse cultivation individual plant crop root dynamic growth model and matrix wetting body dynamic change model combine, the water-saving irrigation carrying out substrate in greenhouse cultivation individual plant crop controls, realize matrix wetting body to mate with the mutual of crop root, under the prerequisite not affecting crop yield and quality, improve the dynamic of substrate in greenhouse cultivation individual plant crop water forecast, real-time, reach real water-saving irrigation, have important practical significance to realizing water-saving substrate in greenhouse cultivation individual plant crop.

Last it is noted that above embodiment only unrestricted the real invention technical scheme in order to explanation, although with reference to above-described embodiment to invention has been detailed description, those of ordinary skill in the art is to be understood that: still can modify to the present invention or equivalent replacement, and not departing from any modification or partial replacement of the spirit and scope of the present invention, it all should be encompassed in the middle of right of the present invention.

Claims (9)

1. be applicable to an irrigation control system for greenhouse individual plant crop, it is characterized in that:

Comprise control centre (100), Zigbee networking module (200), detection module (300) and irrigate module (400);

Control centre (100), Zigbee networking module (200), detection module (300) connect successively;

Control centre (100), Zigbee networking module (200), irrigation module (400) connect successively.

2., by a kind of irrigation control system being applicable to greenhouse individual plant crop according to claim 1, it is characterized in that:

Described control centre (100) comprises host computer (110) and power supply (120);

Host computer (110) and power supply (120) electrical connection.

3., by a kind of irrigation control system being applicable to greenhouse individual plant crop according to claim 1, it is characterized in that:

Described Zigbee networking module (200) comprises gateway (210), ZigBee data acquisition module (220), ZigBee control module (230);

Gateway (210) is connected with ZigBee data acquisition module (220), ZigBee control module (230) respectively.

4., by a kind of irrigation control system being applicable to greenhouse individual plant crop according to claim 1, it is characterized in that:

Described detection module (300) comprises water supply in media sensor (310), air temperature sensor (320), optical sensor (330), air humidity sensor (340);

Water supply in media sensor (310), air temperature sensor (320), optical sensor (330), air humidity sensor (340) are connected with ZigBee data acquisition module (220) respectively.

5., by a kind of irrigation control system being applicable to greenhouse individual plant crop according to claim 1, it is characterized in that:

Described irrigation module (400) comprises magnetic valve (410), drips arrow (420), pipeline (430) and water pump (440);

Magnetic valve (410), water pump (440) are connected with ZigBee control module (230); Magnetic valve (410) is arranged on pipeline (430) and is above communicated with water pump (440).

6., by a kind of irrigation control system being applicable to greenhouse individual plant crop according to claim 1, it is characterized in that:

Control centre (100) forms WLAN by gateway.

7. be applicable to a control method of irrigation for greenhouse individual plant crop, it is characterized in that:

(1) selected cultivation matrix kind, determines the volume ratio of various matrix;

(2) dimensionless analysis is adopted, under utilizing different drip irrigation flow, different water supply time and an arrow different buried depth situation, wetting body top layer horizontal infiltration Distance geometry Vertical Infiltration distance sets up wetting body characteristic model, and sets up wetting body section model and wetting body volume-based model on this basis;

(3) adopt Method for Numerical, utilize under the best growing condition, the root system radius that the root of crop different growing stages is dark and corresponding sets up crop root zone section model and crop root zone volume-based model;

(4) compare with setting moisture content lower limit according to water supply in media sensor current detection substrate water content, judge whether to need to irrigate, judge whether to stop irrigating according to the theoretical irrigation volume of the volume degree of overlapping of crop root zone and wetting body and calculating, actual irrigation amount.

8., by a kind of control method of irrigation being applicable to greenhouse individual plant crop according to claim 7, it is characterized in that described matrix volume ratio is vinegar grain: vermiculite: perlite=2:1:1.

9., by a kind of control method of irrigation being applicable to greenhouse individual plant crop according to claim 7, it is characterized in that:

Control centre (100) detects data according to detection module (300) and calculates crop root zone volume, send and irrigate instruction to irrigating module (400) and timing, when reaching irrigation during sensor assay intervals integral multiple, calculate matrix wetting body volume, the volume Overlapping Calculation of go forward side by side row crop root district and wetting body;

According to the detection data of detection module (300), Penman formula is utilized to calculate Crop Evapotranspiration ET ₀, according to crop coefficient K _c, moisture adjusted coefficient K _Θand ET ₀calculate actual evapotranspiration ET, i.e. theoretical irrigation volume, the irrigation flow of setting and irrigation last and calculate actual irrigation amount, if theoretical irrigation volume is equal with actual irrigation, but the volume degree of overlapping of crop root and wetting body does not meet the demands, but irrigation water, not whole district's distribution, needs to continue to irrigate, until stop when degree of overlapping meets the demands irrigating; Record residue irrigation volume, that is: the amount of theoretical irrigation volume-actual irrigation amount; If actual irrigation amount is less than theoretical irrigation volume, but the volume degree of overlapping of crop root and wetting body meets the demands, and stops irrigating and records residue irrigation volume; Calculate the accumulative residue irrigation volume of a day, that is: the amount of the residue irrigation volume sum of irrigation frequency occurred in one day, if accumulative residue irrigation volume is negative, namely system is normally run; If accumulative residue irrigation volume is positive number, accumulative remaining irrigation volume is carried out supplementary irrigation in first 1 hour sunrise in second day by system automatically.