CN1789992A - Non-destructive detection method for egg freshness by using electromagnetic wave resonant cavity - Google Patents

Abstract

The invention discloses an egg quality lossless detecting method of electromagnetic wave technique, which comprises the following parts: metal resonance cavity, weight sensor, conveying belt and computer. The method comprises the following steps: (1) putting the egg with different filling weighs and freshness in the metal resonance cavity; measuring the deltaf and attenuation of electromagnetic signal; storing the list in the computer to finish the scaling and calibration course; (2) reading the deltaf, attenuation of electromagnetic signal and temperature from the computer when the egg enters into the resonance cavity; obtaining the disposed egg freshness on the conveying belt through checking the graph.

Description

The method of electromagnetic wave resonance cavity Non-Destructive Testing egg freshness by using

Technical field

The present invention relates to a kind of electromagnetic wave technology in the qualitative application of Non-Destructive Testing birds, beasts and eggs.

Background technology

At present, in TradeNet, mostly use sense organ and physical method that egg quality is differentiated and classification,, all can render on the market as long as egg is not an egg inferior.Raised chickens the family in the minority rural area, can differentiate and classification egg roughly in this way; But concerning producing in enormous quantities, big with these method labour intensity, effectiveness of classification is low, and testing result lacks objectivity.

Recently, reported the method for several Non-Destructive Testing egg qualities again.The acoustics ballistic method: its principle is that basis is knocked the sound pulse vibration that egg produces, and does the crackle that spectrum analysis detects egg, and it is 85% that good shell egg detects accuracy rate, and the shortcoming of this method is to detect the quality of eggshell.Optical method: its principle is to utilize the inside quality of optical transmission, refraction and reflex and egg to set up a kind of relation, sets up the method that it detects egg quality by mathematical model.Its freshness classification accuracy rate can reach more than 95%.The shortcoming of this method is the cost height, and measurement result is subjected to the influence of eggshell color and inner constituent.KINETIC METHOD: its principle is to utilize the quality of the impact of egg or vibration performance and egg is set up between the two correlativity.For example, Coucke has studied with the vibration frequency of no damaging impact egg and has set the eggshell characteristic, three-dimensional vibrating model when minimum response frequency has been described, and analyzed correlativity between eggshell index and the dynamic stiffness value, the shortcoming of this method is the Non-Destructive Testing that is difficult to realize egg freshness by using.Electric method: its principle is to utilize the difference of egg conductivity, sets up the quality that relevant model detects egg.For example, people such as Liu Xi have carried out the detection of pH value, TVBN and conductivity to the egg of different freshnesss, and the result shows the reduction along with egg freshness by using, and the conductivity of egg is on a declining curve.The shortcoming of this method is that the difficult quick nondestructive of realizing detects.The microwave transmission reflectometry: its principle is to utilize the transmission of microwave and the inside quality of reflex and egg to set up the freshness that mathematical model detects egg.For example, Volgyi has reported the reflection experiment of egg under the 14.2GHz microwave radiation, the result show reflected signal over time rule be-1dB/30 days.The shortcoming of this method is that sensitivity is low.

Same inventor's the patent No. is that 02125071.5 Chinese patent discloses a kind of " method of ultrahigh frequency resonator cavity continuous coverage bulk material flow ", system relates to a kind of resonance device, particularly a kind of ultrahigh frequency resonance device is used for the method that the flow to bulk material (medium) carries out continuous coverage, but this method has only been studied the flow through frequency deviation Δ f information of resonator cavity of bulk material, can not calculate the moisture of material thus.

Same inventor's application number is that the Chinese patent of 200410040027.X discloses " a kind of material composition and content detecting method ", is to relate to the application of a kind of electromagnetic wave spectrum technology on recognition material composition and content.The core of this method is a relaxation behavior of having considered material, the composition and the content of energy recognition material.But this method complexity can not obtain its electromagnetic wave spectrum characteristic by heating up to egg.

Summary of the invention

The objective of the invention is to overcome the defective of prior art, provide a kind of fast, easily adjust, non-maintaining, good reproducibility and detect the method for egg freshness by using accurately, promptly use the method for electromagnetic wave resonance cavity Non-Destructive Testing egg freshness by using.

By Theory of Electromagnetic Field as can be known, filled the cylindrical E of material for centre shown in Figure 1 ₀₁₀Mould metal resonant cavity, its field component is:

H _θ＝[AJ ₁(βr)+BY ₁(βr)]e ^jωt

$E_z=-j\sqrt{\frac{\mathrm{\μ}}{\mathrm{\ϵ}}}[A{J}_0\left(\mathrm{\βr}\right)+B{Y}_0\left(\mathrm{\βr}\right)]e^{\mathrm{j\ωt}}$

In the following formula, A, B and $\mathrm{\β}=\sqrt{\mathrm{\ϵ\μ}}\·\mathrm{\ω}$ It is respectively the analog value in a in the chamber, b, c district.Utilize boundary condition to get:

A _aJ ₀(β _aa)+B _aY ₀(β _aa)＝0

A _aJ ₁(β _ab)+B _aY ₁(β _ab)-A _bJ ₁(β _bb)-B _bY ₁(β _bb)＝0

$\frac{A_a}{\sqrt{{\mathrm{\ϵ}}_a}}{J}_0\left({\mathrm{\β}}_{a}b\right)+\frac{B_a}{\sqrt{{\mathrm{\ϵ}}_a}}{Y}_0\left({\mathrm{\β}}_{a}b\right)-\frac{A_b}{\sqrt{{\mathrm{\ϵ}}_b}}{J}_0\left({\mathrm{\β}}_{b}b\right)-\frac{B_b}{\sqrt{{\mathrm{\ϵ}}_b}}{Y}_0\left({\mathrm{\β}}_{b}b\right)=0$

A _bJ ₁(β _bc)+B _bY ₁(β _bc)-A _cJ ₁(β _cc)＝0

$\frac{A_b}{\sqrt{{\mathrm{\ϵ}}_b}}{J}_0\left({\mathrm{\β}}_{b}c\right)+\frac{B_b}{\sqrt{{\mathrm{\ϵ}}_b}}{Y}_0\left({\mathrm{\β}}_{b}c\right)-\frac{A_c}{\sqrt{{\mathrm{\ϵ}}_c}}{J}_0\left({\mathrm{\β}}_{c}c\right)=0$

In the following formula, ${\mathrm{\β}}_a=\mathrm{\ω}\sqrt{{\mathrm{\μ}}_a{\mathrm{\ϵ}}_a},{\mathrm{\β}}_b=\sqrt{\frac{{\mathrm{\ϵ}}_b}{{\mathrm{\ϵ}}_a}}{\mathrm{\β}}_a,{\mathrm{\β}}_c=\sqrt{\frac{{\mathrm{\ϵ}}_c}{{\mathrm{\ϵ}}_a}}{\mathrm{\β}}_a$

Definition M ₁=J ₀(β _bB) Y ₁(β _bC)-J ₁(β _bC) Y ₀(β _bB)

M ₂＝J ₁(β _bb)Y ₁(β _bc)-J ₁(β _bc)Y ₁(β _bb)

M ₃＝J ₀(β _bb)Y ₀(β _bc)-J ₀(β _bc)Y ₀(β _bb)

M ₄＝J ₁(β _bb)Y ₀(β _bc)-J ₀(β _bc)Y ₁(β _bb)

$M=\frac{Y_1\left({\mathrm{\β}}_{a}b\right)/J_1\left({\mathrm{\β}}_{a}b\right)-Y_0\left({\mathrm{\β}}_{a}a\right)/J_0\left({\mathrm{\β}}_{a}a\right)}{Y_0\left({\mathrm{\β}}_{a}b\right)/J_0\left({\mathrm{\β}}_{a}b\right)-Y_0\left({\mathrm{\β}}_{a}b\right)/J_0\left({\mathrm{\β}}_{a}a\right)}$

$=1+\frac{1}{F}\·\frac{a}{b}\·\frac{J_0\left({\mathrm{\β}}_{a}a\right)}{J_1\left({\mathrm{\β}}_{a}a\right)}$

$F=[Y_0\left({\mathrm{\β}}_{a}a\right)J_0\left({\mathrm{\β}}_{a}b\right)-Y_0\left({\mathrm{\β}}_{a}b\right)J_0\left({\mathrm{\β}}_{a}a\right)]\frac{\mathrm{\π}{\mathrm{\β}}_{a}a}{2}$

Get after utilizing above-mentioned equation simplification:

$\frac{{\mathrm{\ϵ}}_c}{{\mathrm{\ϵ}}_a}=\frac{\frac{b^2}{c^2}[1+\frac{{\left({\mathrm{\β}}_{a}b\right)}^2}{8}][M-M_b(1-\frac{{\left({\mathrm{\β}}_{a}b\right)}^2}{8})]}{1+\frac{{\left({\mathrm{\β}}_{a}b\right)}^2}{8}[M-M_b]}$

${\mathrm{<figure-callout\; id="1"\; label="Q"\; filenames="A20051004869600111.png"\; state="\{\{state\}\}">Q</figure-callout>}}_1=Q_0\frac{[\frac{a^2}{c^2{F}_b^2}+\frac{b^2}{c^2}(\frac{{\mathrm{\&epsiv;}}_b}{{\mathrm{\&epsiv;}}_a}-1)][1-2{\mathrm{\&beta;}}_c(b-c)\frac{J_1\left({\mathrm{\&beta;}}_{c}c\right)}{J_0\left({\mathrm{\&beta;}}_{c}c\right)}]+\frac{{\mathrm{\&epsiv;}}_c-{\mathrm{\&epsiv;}}_b}{{\mathrm{\&epsiv;}}_a}}{\frac{a}{a+l}\sqrt{\frac{f_0}{f_1}}[\frac{a(a+l)}{l^2{F}_b^2}+\frac{b^2}{c^2}\left(\frac{{\mathrm{\&epsiv;}}_b-1}{{\mathrm{\&epsiv;}}_a}\right)][1-2{\mathrm{\&beta;}}_b(b-c)\frac{J_1\left({\mathrm{\&beta;}}_{c}c\right)}{J_0\left({\mathrm{\&beta;}}_{c}c\right)}+\frac{{\mathrm{\&epsiv;}}_c-{\mathrm{\&epsiv;}}_b}{{\mathrm{\&epsiv;}}_a}]}$

$+2Q_0^2\frac{b-c}{c}\frac{{\mathrm{\&epsiv;}}_b}{{\mathrm{\&epsiv;}}_a}\mathrm{tg}{\mathrm{\&delta;}}_b$

By following formula as seen, only need measure the frequency deviation Δ f=f that sample enters the resonant cavity front and back ₁-f ₀With the decay of electromagnetic wave signal, can be finally inversed by the DIELECTRIC CONSTANT of sample _c

The dielectric property of analyzing egg as can be known, the Main Ingredients and Appearance of egg is protein, fat and water.The freshness of egg and its moisture, protein are relevant with fatty quality.Because the specific inductive capacity of water is much larger than the specific inductive capacity of protein and fat, liquid water content is very big to electromagnetic influence in the egg.Therefore, the method for the electromagnetic wave resonance cavity Non-Destructive Testing egg freshness by using of introduction of the present invention have good reproducibility, easily adjust, non-maintaining, can be fast and detect the freshness of egg exactly.

Experimental result:

Under the indoor environment of experiment condition shown in Figure 2 and 25 ℃, see shown in Figure 3 with the electromagnetic spectrum instrument measurement result of Jinhuitong Wire-less and Microwave Technology Inst., Kunming's exploitation.The relation in the decay of electromagnetic wave signal and egg storage time is seen Fig. 4, and the frequency of electromagnetic wave signal and the relation in egg storage time are seen Fig. 5.Above experimental result and accord with theoretical analysis.

On the other hand, the frequency deviation Δ f of the metal resonant cavity that different freshness eggs cause is not only relevant with the weight of egg with the decay of electromagnetic wave signal, and is also relevant with temperature.Therefore, must carry out constant temperature, just can be used to measure the freshness of egg behind the constant temperature measuring system.For this reason, increase again real-time continuous measure behind the electronic scales of weight of egg and the thermostat can the continuous coverage egg freshness.The calibration calibration process is as follows: the egg of Different Weight, identical freshness is sent into resonant cavity, measure the instantaneous frequency deviation Δ f of resonant cavity and the decay of electromagnetic wave signal simultaneously, tabulation deposits computing machine in; The egg of identical weight, different freshnesss is sent into resonant cavity, measure the resonance frequency deviation Δ f of resonant cavity and the decay of electromagnetic wave signal simultaneously, tabulation deposits computing machine in, finishes the calibration calibration process.During normal the use, sampling constantly computing machine read egg from USB interface and enter the instantaneous frequency deviation Δ f that produces behind the cylindrical metal resonant cavity, the decay and the weight of electromagnetic wave signal, after processing such as table look-up, can show the freshness of egg in this moment resonant cavity.

The employed device of method of electromagnetic wave resonance cavity Non-Destructive Testing egg freshness by using of the present invention comprises metal resonant cavity, weight sensor, travelling belt and computing machine, described metal resonant cavity is by metal resonant cavity excitation of electromagnetic wave, constant temperature, described travelling belt is by the metal resonant cavity, one end of weight sensor is connected with travelling belt, the other end is connected with computing machine, weight sensor is used for the weight that weighing enters an egg of metal resonant cavity, and this method may further comprise the steps:

(1), in advance the egg of Different Weight and different freshnesss is entered frequency deviation Δ f in the resonant cavity and measures to tabulate with the decay of electromagnetic wave signal and deposit computing machine in, finish the calibration calibration process;

(2), allow the egg that need to detect enter resonant cavity successively, sampling constantly computing machine read the instantaneous frequency deviation Δ f that egg causes, the decay and the weight of electromagnetic wave signal, after processing such as table look-up, can show the freshness of this egg on this moment travelling belt.

The present invention provides the strong interaction district of an electromagnetic wave and egg, and promptly the metal resonant cavity adopts the distribution parameter resonator cavity can make accuracy of detection higher.Described metal resonant cavity can be open, also can be enclosed, and its shape can be multiple shape, as: cylindrical, square, planar shaped etc.; When the metal resonant cavity is sealing, opening should be arranged on the wall of chamber, allow travelling belt therefrom pass; When resonant cavity when open, travelling belt should be near resonant cavity, its distance should be less than an electromagnetic wavelength of the resonant cavity of excitation; Described travelling belt does not absorb electromagnetic wave.In general, the single resonant cavity that enters of inspected object detects comparatively simple.

According to top method, this professional those of ordinary skill just can be implemented the technology of the present invention, realizes goal of the invention.

Advantage of the present invention:

Compare with optical method, good, the easy adjustment of measurement stability of the present invention, non-maintaining, and measurement result is not subjected to the influence of eggshell color; Compare with electric method, the present invention is easy to realize fast that the freshness of egg detects; Compare with the microwave transmission reflectometry, the present invention is highly sensitive, measures accurately.The present invention is applicable to the detection of all bird egg freshness.

Description of drawings

Fig. 1 is cylindrical metal resonant cavity and coordinate system thereof.

Fig. 2 is provided with the cylindrical metal resonant cavity of travelling belt in being.

Fig. 3 is the electromagnetic spectrum figure of the different freshness eggs measured under experiment condition shown in Figure 2.

Fig. 4 is the graph of a relation of egg storage time and electromagnetic wave signal decay.

Fig. 5 is the graph of a relation of egg storage time and electromagnetic wave resonance cavity frequency deviation Δ f.

Fig. 6 is the apparatus structure synoptic diagram among the embodiment.

Fig. 7 is the circuit block diagram among the embodiment.

Among the figure: 1-egg to be detected, 2-travelling belt, 3-metal resonant cavity, 4-electromagnetic wave coupler device, 5-hole, 6-emission coefficient, 7-interface, 8-receiving system, 9-computing machine, 10-weight sensor.

Embodiment

Embodiment: as Fig. 6, shown in Figure 7.

Present embodiment adopts cylindrical metal resonant cavity 3, it highly is 20mm, diameter is 300mm, material is a brass, and travelling belt 2 materials are teflon, and the center square hole 5 of 60 * 60mm is arranged on the chamber wall of metal resonant cavity 3, travelling belt 2 passes its center square hole 5, diameter 3mm, long for the electromagnetic wave coupler device 4 of 10mm is used for coupling generation electromagnetic wave, electromagnetic wave is produced by frequency sweep circuit, is fed to resonant cavity by coupling device; 6 is the electromagnetic wave emission coefficient, is made up of frequency sweep circuit, is used to generate electromagnetic waves; 7 is interface circuit, is respectively applied for computing machine is connected with emission coefficient, receiving system is connected with computing machine with weighing device is connected with computing machine; 8 is receiving system, is made up of detector amplifier and DSP; 9 is computing machine; Weighing system 10 is an electronic scales; The hollow core arrow is represented the conveyer belt direction.

Egg 1 to be detected is arranged on the travelling belt 2, successively by cylindrical metal resonant cavity 3, and the frequency deviation Δ f when computing machine USB mouth is read egg and entered resonator and the decay of electromagnetic wave signal.

Among this embodiment, the electromagnetic wave resonant circuit contains electromagnetic wave resonance cavity, frequency sweep circuit, wave detector, amplifier and DSP.

Above example only is described further invention, and scope of the present invention is not subjected to the limitation of illustrated embodiment.

Claims (5)

1, a kind of method of electromagnetic wave resonance cavity Non-Destructive Testing egg freshness by using, it is characterized in that employed device comprises metal resonant cavity, weight sensor, travelling belt and computing machine, described metal resonant cavity is by metal resonant cavity excitation of electromagnetic wave, constant temperature, described travelling belt is by the metal resonant cavity, one end of described weight sensor is connected with travelling belt, the other end is connected with computing machine, weight sensor is used for the weight that weighing enters an egg of metal resonant cavity, and this method may further comprise the steps:

(1), the frequency deviation Δ f that in advance egg of Different Weight and different freshnesss entered in the resonant cavity measures with the decay of electromagnetic wave signal, tabulates and deposits computing machine in, finishes the calibration calibration process;

(2), allow the egg that need to detect enter resonant cavity successively, sampling constantly computing machine read the instantaneous frequency deviation Δ f that egg causes, the decay and the weight of electromagnetic wave signal, after processing such as table look-up, can show the freshness of this egg on this moment travelling belt.

2, the method for electromagnetic wave resonance cavity Non-Destructive Testing egg freshness by using as claimed in claim 1 is characterized in that described metal resonant cavity is the distribution parameter resonator cavity.

3, the method for electromagnetic wave resonance cavity Non-Destructive Testing egg freshness by using as claimed in claim 1 or 2, it is characterized in that described metal resonant cavity is open, described travelling belt is near resonant cavity, and its distance is less than an electromagnetic wavelength of the resonant cavity of excitation.

4, the method for electromagnetic wave resonance cavity Non-Destructive Testing egg freshness by using as claimed in claim 1 or 2 is characterized in that described metal resonant cavity is enclosed, on its chamber wall opening is arranged, and described travelling belt therefrom passes.

5, the method for electromagnetic wave resonance cavity Non-Destructive Testing egg freshness by using as claimed in claim 1 is characterized in that described travelling belt does not absorb electromagnetic wave.

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