CN104374705A - Beef freshness detection device and detection method - Google Patents

Abstract

The invention discloses a beef freshness detection device and detection method, the beef freshness detection device includes an opaque casing, a controller, a laser array, a spectrometer, a light intensity adjusting device, a rectangular container which is arranged in the casing and is provided with an opening on the upper end, a rectangular sample tray arranged in the container, a bracket arranged on a base plate of the casing, a light emitting head which is arranged on the bracket and used for irradiating light to a sample, and a light receiving head used for receiving reflected light of the sample; the light intensity adjusting device, the laser array and the light emitting head are orderly electrically connected, the light receiving head and the spectrometer are electrically connected, the container and the sample tray are made of a magnetic-impermeable material, the container is provided with a liquid, the sample tray is suspended above the liquid surface, a plurality of vertical holes of m order matrix arrangement are arranged on the bottom of the container, and the beef freshness detection device has the advantages of fast detection speed; more point detection, reliable detection data and higher precision.

Description

Degree of beef freshness pick-up unit and detection method thereof

Technical field

The present invention relates to measurement techniques for quality detection of meat detection technique field, especially relate to and a kind ofly can detect the degree of beef freshness pick-up unit that beef is whether corrupt and detection method thereof accurately and rapidly.

Background technology

Beef has nutritious and that mouthfeel is good feature, dark liking by consumers in general.

But beef is easy to polluted and go bad.In storage process, along with propagation and a series of physicochemical change of microorganism, the freshness of beef decreases.The nutritional labeling that protein, fat and carbohydrates etc. enrich is utilized by bacterium and enzyme, produces the sour gas of ammonia, sulfuration ammonia, aldehydic acid, aldehyde, ketone, ethanethio, alcohol and carboxylic acid.Aldehyde in metabolic product, ketone, ester and other low molecular compound make beef produce peculiar smell.

At present, usually spectrum stimulus light source irradiation sample (namely adopting a laser array often opened or LED to impinge upon on sample) is adopted both at home and abroad, and gather incident illumination be mapped to sample after diffuse or through the reflected light of sample, diffuse reflection spectrum or reflectance spectrum are analyzed, finally realizes the detection to sample quality; But it is less to there is the Detection Information amount collected in this detection method, the deficiency that the precision of detection is lower.

Chinese patent Authorization Notice No.: CN101769889A, authorized announcement date on July 7th, 2010, disclose the electric nasus system that a kind of quality of agricultural product detects, comprise one and mainly complete gas enrichment module to low concentration odor trap, one air chamber gas path module and the sensor array mainly olfactory signal being converted into electric signal, one mainly carries out filtering to sensor array output signal, analog to digital conversion, the Conditioning Circuits of Sensor of feature extraction and data preprocessing module, a pair signal carries out identifying and judging, and with the embedded system that data store, one display and result output module, described gas enrichment module is formed by being filled with the adsorption tube of adsorbent, heating wire and attemperating unit.This invention has function singleness, the deficiency that detection time is long.

Summary of the invention

The present invention is the deficiency in order to overcome the low and length consuming time of detection method precision of the prior art, provides a kind ofly to detect beef whether corrupt degree of beef freshness pick-up unit and detection method thereof accurately and rapidly.

To achieve these goals, the present invention is by the following technical solutions:

A kind of degree of beef freshness pick-up unit, comprise light tight housing, controller, laser array, spectrometer, light intensity regulating device, be located at the rectangular vessel of the upper end open in housing, the rectangle sample pallet be located in container, the support be located on Housing Base, be located on support for the light emitting head to sample irradiation light and the light-receiving head for the reflected light that receives sample; Light intensity regulating device, laser array, light emitting head are electrically connected successively, and light-receiving head is electrically connected with spectrometer; Container and sample tray are made by non-magnet_conductible material, liquid is provided with in described container, described sample tray is suspended on liquid surface, container bottom is provided with several vertical cores of the arrangement in m rank square formation, the equal upward opening of each vertical core and be equipped with location electromagnet in vertical core, location magnet piece is provided with in the middle part of described sample tray, metal column upper end through sample tray lower surface is connected with location magnet piece, and the polarity of the magnetic pole of location electromagnet and magnet piece opposite end, location is contrary;

Each edge of sample tray is equipped with some pieces of traction magnet pieces, each side of container is equipped with some blocks of power for traction magnet; Light intensity regulating device, spectrometer, each block of location electromagnet and each block of power for traction magnet are all electrically connected with controller.

Light intensity regulating device of the present invention is for the light intensity of the light source that regulates laser array to send, each location is used for locating to sample tray with electromagnet, power for traction magnet moves for drawing sample tray, the setting of liquid is used for providing the buoyancy departing from and be located by connecting with container to sample tray, thus the present invention can be detected the multiple points on sample, and data analysis is carried out to the detection signal that each point of irradiation obtains, and obtain the freshness of beef sample, that detects is wider, Detection Information more comprehensively, improves the reliability of testing result.

Light detects the principle learning degree of beef freshness: after light beam irradiates sample, because the different chemical characteristic group comprised in different freshness sample is different, therefore the degree of absorption for different wave length incident light is different, thus in reflected light, the intensity of each wavelength light is different, therefore can go the freshness of characterizing sample according to these information.But,

If the light intensity of incident light is fixed, then incident light is stably radiated on sample, and each chemical group in sample is in state of saturation for the degree of absorption of different wavelengths of light, although can obtain Detection Information, but quantity of information is not enriched, accurately determining of detection is lower.

The present invention is that the incident light adopting light intensity constantly to change irradiates sample, in the intensity of incident light gradually in the large or change procedure that reduces, the absorption of different groups to respective wavelength light is gradually large or reduction, now the degree of absorption of group is in unsaturation, saturated diminuendo process, comprise more Detection Information in reflected light, thus enable the detection signal obtained symbolize the freshness of beef more accurately.

Therefore, the present invention has that detection speed is fast, and check point is more, detects the reliability of data and the higher feature of precision.

As preferably, motor is equipped with in container below each vertical core, each location electromagnet is connected with the vertical rotating shaft of each motor respectively, location electromagnet is provided with keeper, keeper upper end offers M shape groove, metal column lower end is provided with the M shape projection corresponding with M shape groove, and each motor is electrically connected with controller.Metal column is provided with spring, and keeper adopts metal material to make.

Motor rotates for driving sample tray, thus makes incident illumination be mapped on the difference of sample, and point detected in testing process is more, comprises freshness information more in the detection signal of acquisition.

As preferably, described laser array comprises 6 and bundles and the single wavelength laser that is arranged in order of wavelength, and the wavelength of each single wavelength laser is respectively 630nm, 925nm, 534nm, 780nm, 610nm and 730nm.The present invention is directed to the physicochemical property of beef, select the laser instrument of above 6 wavelength to detect, more can give prominence to the detection feature of beef, improve the accuracy detected.

As preferably, described light intensity regulating device comprises data collecting card and power amplifier, described data collecting card is provided with the signal input interface for being electrically connected with controller, described data collecting card is electrically connected with the input end of power amplifier, and the output terminal of described power amplifier is connected with the power electric of laser array.

Controller produces the waveform for controlling intensity variation, this waveform signal gathers by data collecting card, and output on power amplifier, the output terminal of power amplifier is connected with the power electric of laser array, thus realize the adjustment to the light intensity of the light source that laser array sends by the power supply controlling laser array, and by the incident light of light emitting head to sample irradiation Strength Changes.

As preferably, support is L-shaped, comprises horizon bar and column; Light emitting head is connected with horizon bar respectively by montant with light-receiving head; Each piece of traction magnet piece is all in bar shaped, and the pole polarity outside each piece of traction magnet piece is identical.

A detection method for degree of beef freshness pick-up unit, comprises the steps:

(6-1) according to CNS GB/T 5009.44-2003, detect the total volatile basic nitrogen TVB-N value of different resting period beef sample, and obtain and m ²the freshness threshold that individual sample detection point is corresponding respectively ${\mathrm{SNR}}_{\mathrm{thre}1},{\mathrm{SNR}}_{\mathrm{thre}1},...,{\mathrm{SNR}}_{{\mathrm{threm}}^2};$

(6-2) sample preparation: choose sheet meat as detected sample from beef to be detected;

(6-3) detect: controller is electrically connected with light intensity regulating device, spectrometer, each block of location electromagnet and each block of power for traction magnet, sample is kept flat on sample tray;

(6-3-1) controller is by being energized and power-off to each each block of location electromagnet and each block of power for traction magnet, and Quality control pallet moves to each vertical core along bow font;

(6-3-2) after metal column inserts a vertical core, the detection light that controller regulates laser array to export by light intensity regulating device, detect light and rise to maximal value MAT from 0 according to sinusoidal curve, then drop to 0 from maximal value MAT according to sinusoidal curve; Detect rear spectrometer and obtain m ²individual detection signal Spect (t);

(6-4) controller is to m ²individual detection signal Spect (t) all does following data processing:

Detection signal Spect (t) is inputted one deck accidental resonance model:

In, controller calculates V (x, t, α) for the first order derivative of x, second derivative and three order derivatives, and makes equation equal 0, obtains two layers of accidental resonance model:

Setting noise intensity the critical value calculating A is the critical value of A is substituted in one deck accidental resonance model, and set X ₀(t)=0, sn ₀=0, with quadravalence jade for asking rain Ge Kuta Algorithm for Solving one deck accidental resonance model, obtain $x_{n-1}\left(t\right)=x_n\left(t\right)+1/6[{\left(k_1\right)}_n+(2-\sqrt{2}){\left(k_2\right)}_n+(2+\sqrt{2}){\left(k_3\right)}_n+{\left(k_4\right)}_n],$ n＝0，1，…，N-1

Wherein undetermined coefficient:

(k ₁) _n＝α(αx _n-1(t)) ²b(αx _n-1(t)) ³+sn _n-1

${\left(k_2\right)}_n=a({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{3})-b{({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{3})}^3+{\mathrm{sn}}_{n-1}$

${\left(k_3\right)}_n=a({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{{\left(k_2\right)}_{n-1}}{3})-b{({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{\sqrt{2}-1}{3}{\left(k_1\right)}_{n-1}+\frac{2-\sqrt{2}}{3}{\left(k_2\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}$

${\left(k_4\right)}_n=a({3\mathrm{\αx}}_{n-1}\left(t\right)+{\left(k_3\right)}_{n-1})-b{({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{\sqrt{2}}{3}{\left(k_2\right)}_{n-1}+\frac{2-\sqrt{2}}{3}{\left(k_3\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}$

Wherein, x _nt n order derivative that () is x (t), sn _n-1the value of n-1 order derivative at t=0 place of S (t), sn _n+1the value of n+1 order derivative at t=0 place of S (t), n=0,1 ..., N-1; Obtain x ₁(t), x ₂(t) ..., x _n+1the value of (t);

Controller is to x ₁(t), x ₂(t) ..., x _n+1t () carries out integration, obtain x (t), and obtain x (t) produces accidental resonance moment optimal detection moment time t1 in the double-deck stochastic system of one deck accidental resonance model and two layers of accidental resonance model composition, optimum transient motion acceleration alpha 1, and determine the noise D1 corresponding to t1 and α 1:

Controller utilizes formula calculate the signal to noise ratio (S/N ratio) that double-deck stochastic resonance system exports; Wherein, Δ U=α ²/ 4b; Obtain m ²individual output signal-to-noise ratio ${\mathrm{SNR}}_{\mathrm{thre}1},{\mathrm{SNR}}_{\mathrm{thre}1},...,{\mathrm{SNR}}_{{\mathrm{threm}}^2};$

(6-5) controller utilizes formula calculate the output signal-to-noise ratio error QE corresponding to kth group pivoting angle data _k, wherein, k=1 ..., m ²;

Controller calculates and meets QE _kthe number M of the output signal-to-noise ratio error of≤5% ₁; Controller calculates and meets QE _kthe number M of the output signal-to-noise ratio error of > 5% ₂;

If (6-6) then the fresh judgement of sample made by controller;

If then the stale judgement of sample made by controller;

Otherwise, return step (6-3-1), sample detected again and carries out data processing.

As preferably, motor is equipped with in container below each vertical core, each location electromagnet is connected with the vertical rotating shaft of each motor respectively, location electromagnet is provided with keeper, keeper upper end offers M shape groove, metal column lower end is provided with the M shape projection corresponding with M shape groove, and each motor is electrically connected with controller;

Step (6-3-2) is replaced by following step:

After metal column inserts a vertical core, the detection light that controller regulates laser array to export by light intensity regulating device, described detection light rises to maximal value MAT from 0 according to sinusoidal curve, then drops to 0 from maximal value MAT according to sinusoidal curve; In testing process, controller control with metal column insert the corresponding motor of vertical core rotating shaft to drive sample tray to rotate 1 to 2 all, spectrometer obtains detection signal Spect (t).

As preferably, the thickness of described sheet meat is 26 to 68mm.

As preferably, the incident angle of light emitting head is 15 to 60 degree.

As preferably, the span of MAT is 98 luxs, lux to 210.

Therefore, the present invention has following beneficial effect: (1) detection speed is fast; (2) check point is more, and the reliability and the precision that detect data are higher.

Accompanying drawing explanation

Fig. 1 is a kind of structural representation of the present invention;

Fig. 2 is a kind of structural representation of sample tray of the present invention;

Fig. 3 is a kind of structural representation of metal column of the present invention, vertical core, motor, location electromagnet and keeper;

Fig. 4 is a kind of theory diagram of embodiments of the invention 1;

Fig. 5 is the Strength Changes schematic diagram of detection light of the present invention;

Fig. 6 is a kind of process flow diagram of embodiments of the invention 1.

In figure: spectrometer 1, light intensity regulating device 2, container 3, sample tray 4, support 5, light emitting head 6, light-receiving head 7, vertical core 8, location electromagnet 9, metal column 11, traction magnet piece 12, power for traction magnet 13, motor 14, keeper 15, M shape groove 16, M shape projection 17, data collecting card 18, power amplifier 19, laser array 20, Housing Base 21, spring 23, controller 24.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention will be further described.

Embodiment 1

Embodiment is as shown in Figure 1, Figure 2, Figure 3, Figure 4 a kind of degree of beef freshness pick-up unit, as shown in Figure 4, comprise light tight housing, controller 24, laser array 20, spectrometer 1, light intensity regulating device 2, as shown in Figure 1, be located at the rectangular vessel 3 of the upper end open in housing, the rectangle sample pallet 4 be located in container, the support 5 be located on Housing Base 21, be located on support for the light emitting head 6 to sample irradiation light and the light-receiving head 7 for the reflected light that receives sample; Light intensity regulating device, laser array, light emitting head are electrically connected successively, and light-receiving head is electrically connected with spectrometer; Container and sample tray are made by plastic material, liquid is provided with in container, sample tray is suspended on liquid surface, as shown in Figure 1, container bottom is provided with 16 vertical cores 8 in 4 rank square formation arrangements, the equal upward opening of each vertical core and be equipped with location electromagnet 9 in vertical core, location magnet piece is provided with in the middle part of sample tray, metal column 11 upper end through sample tray lower surface is as shown in Figure 3 connected with location magnet piece, and the polarity of the magnetic pole of location electromagnet and magnet piece opposite end, location is contrary;

As shown in Figure 2, each edge of sample tray is equipped with 4 pieces of traction magnet pieces 12, each side of container is equipped with 4 blocks of power for traction magnet 13; As shown in Figure 4, light intensity regulating device, spectrometer, each block of location electromagnet and each block of power for traction magnet are all electrically connected with controller.

Laser array comprises 6 and bundles and the single wavelength laser that is arranged in order of wavelength, and the wavelength of each single wavelength laser is respectively 630nm, 925nm, 534nm, 780nm, 610nm and 730nm.

As shown in Figure 4, light intensity regulating device comprises data collecting card 18 and power amplifier 19, data collecting card is provided with the signal input interface for being electrically connected with controller, described data collecting card is electrically connected with the input end of power amplifier, and the output terminal of power amplifier is connected with the power electric of laser array.

Support is L-shaped, comprises horizon bar and column; Light emitting head is connected with horizon bar respectively by montant with light-receiving head; Each piece of traction magnet piece is all in bar shaped, and the pole polarity outside each piece of traction magnet piece is identical.Motor is stepper motor.

A detection method for degree of beef freshness pick-up unit, comprises the steps:

According to CNS GB/T 5009.44-2003, detect the total volatile basic nitrogen TVB-N value of different resting period beef sample, and obtain the freshness threshold SNR corresponding respectively with 16 sample detection points _thre1, SNR _thre1..., SNR _thre16;

Freshness threshold SNR _thre1, SNR _thre1..., SNR _thre16the method obtained is as follows:

Detect the total volatile basic nitrogen numerical value of the fresh beef of just having slaughtered, after having detected, beef is put in cold storage plant and stores, second day, 3rd day, take out beef to continue to detect the total volatile basic nitrogen numerical value of beef, has detected at every turn and all put into cold storage plant and store, when the total volatile basic nitrogen numerical value of certain day sample exceeds standard for the first time, then adopt following step to detect in the sample of this day, 16 SNR obtained are freshness threshold SNR _thre1, SNR _thre1..., SNR _thre16.

Freshness threshold and storage condition are relevant, detect obtained freshness threshold to the beef sample stored in certain temperature, pressure and humidity

SNR _thre1, SNR _thre1..., SNR _thre16, the freshness detecting the beef stored under the same conditions can only be used for.

Before detection, regulate the height of water level in container, the reflected light that light emitting head is launched can just in time enter in light-receiving head after sample reflection;

As shown in Figure 6, step 100, sample preparation: choose the thick sheet meat of 40mm as detected sample from beef to be detected;

Step 200, detects: be electrically connected with light intensity regulating device, spectrometer, each block of location electromagnet and each block of power for traction magnet by controller, kept flat by sample on sample tray;

Step 210, controller is by being energized and power-off to each each block of location electromagnet and each block of power for traction magnet, and Quality control pallet moves to each vertical core according to order as shown by the arrows in Figure 1 in bow font;

Step 220, after metal column inserts a vertical core, the detection light that controller regulates laser array to export by light intensity regulating device, detects light and rises to maximal value MAT from 0 according to sinusoidal curve, then drop to 0 from maximal value MAT according to sinusoidal curve; Detect rear spectrometer and obtain m ²individual detection signal Spect (t);

Step 300, data processing: controller is to m ²individual detection signal Spect (t) all does following data processing:

Detection signal Spect (t) is inputted one deck accidental resonance model:

In, wherein, V (x, t, α) be potential function, x (t) is Brownian movement Particles Moving lopcus function, a, b is the constant of setting, ξ (t) is external noise, and D is with the external noise intensity of 0.01 stepping in [0,1] scope, N (t) grasps noise in being for periodic sinusoidal signal, A is signal amplitude, and f is signal frequency, and t is run duration, for phase place, if

Controller calculates V (x, t, α) for the first order derivative of x (f), second derivative and three order derivatives, and makes equation equal 0, obtains two layers of accidental resonance model:

Setting noise intensity the critical value calculating A is the critical value of A is substituted in one deck accidental resonance model, and set X ₀(t)=0, sn ₀=0., with quadravalence jade for asking rain Ge Kuta Algorithm for Solving one deck accidental resonance model, obtains $x_{n-1}\left(t\right)=x_n\left(t\right)+1/6[{\left(k_1\right)}_n+(2-\sqrt{2}){\left(k_2\right)}_n+(2+\sqrt{2}){\left(k_3\right)}_n+{\left(k_4\right)}_n],$ n＝0，1，…，N-1

And calculate undetermined coefficient:

(k ₁) _n＝α(αx _n-1(t)) ²b(αx _n-1(t)) ³+sn _n-1

${\left(k_2\right)}_n=a({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{3})-b{({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{3})}^3+{\mathrm{sn}}_{n-1}$

${\left(k_3\right)}_n=a({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{{\left(k_2\right)}_{n-1}}{3})-b{({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{\sqrt{2}-1}{3}{\left(k_1\right)}_{n-1}+\frac{2-\sqrt{2}}{3}{\left(k_2\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}$

${\left(k_4\right)}_n=a({3\mathrm{\αx}}_{n-1}\left(t\right)+{\left(k_3\right)}_{n-1})-b{({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{\sqrt{2}}{3}{\left(k_2\right)}_{n-1}+\frac{2-\sqrt{2}}{3}{\left(k_3\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}$

Wherein, x _nt n order derivative that () is x (t), sn _n-1the value of n-1 order derivative at t=0 place of S (t), sn _n+1the value of n+1 order derivative at t=0 place of S (t), n=0,1 ..., N-1; Obtain x ₁(t), x ₂(t) ..., x _n+1the value of (t);

Controller is to x ₁(t), x ₂(t) ..., x _n+1t () carries out integration, obtain x (t), and obtain x (t) produces accidental resonance moment optimal detection moment time t1 in the double-deck stochastic system of one deck accidental resonance model and two layers of accidental resonance model composition, optimum transient motion acceleration alpha 1, and determine the noise D1 corresponding to t1 and α 1; D ₁for the value of in D; D is that the value of D and time correlation, be aware of t with a function of 0.01 loop cycle stepping in [0,1] scope ₁moment, D ₁just determine.

Controller utilizes formula calculate the signal to noise ratio (S/N ratio) that double-deck stochastic resonance system exports; Wherein, Δ U=α ²/ 4b; Obtain m ²individual output signal-to-noise ratio ${\mathrm{SNR}}_1,{\mathrm{SNR}}_2,...,{\mathrm{SNR}}_{m^2};$

Step 400, error calculation:

Controller utilizes formula calculate the output signal-to-noise ratio error QE corresponding to kth group pivoting angle data _k, wherein, k=1 ..., m ²;

Controller calculates and meets QE _kthe number M of the output signal-to-noise ratio error of≤5% ₁; Controller calculates and meets QE _kthe number M of the output signal-to-noise ratio error of > 5% ₂;

Step 500, judges:

If then the fresh judgement of sample made by controller;

If then the stale judgement of sample made by controller;

Otherwise, return step 210, sample detected again and carries out data processing.

M in the present embodiment ₁=14, therefore, the fresh judgement of sample made by controller.

Embodiment 2

In embodiment 2, as shown in Figure 3, motor 14 is provided with in container below vertical core, location electromagnet is connected with the vertical rotating shaft of motor, location electromagnet is provided with keeper 15, keeper upper end offers M shape groove 16, and metal column lower end is provided with the M shape projection 17 corresponding with M shape groove, and motor is provided with the signal output port for being electrically connected with controller.Metal column is provided with spring 23.

Step 220 in embodiment 2 is replaced by following step:

After metal column inserts a vertical core, the detection light that controller regulates laser array to export by light intensity regulating device, described detection light rises to maximal value MAT from 0 according to sinusoidal curve, then drops to 0 from maximal value MAT according to sinusoidal curve; In testing process, the rotating shaft that controller controls the motor corresponding with the vertical core that metal column inserts drives sample tray to rotate 1 week, and spectrometer obtains detection signal Spect (t).

Other structure in embodiment 2 and method part in the same manner as in Example 1.

Should be understood that the present embodiment is only not used in for illustration of the present invention to limit the scope of the invention.In addition should be understood that those skilled in the art can make various changes or modifications the present invention, and these equivalent form of values fall within the application's appended claims limited range equally after the content of having read the present invention's instruction.

Claims (10)

1. a degree of beef freshness pick-up unit, it is characterized in that, comprise light tight housing, controller (24), laser array (20), spectrometer (1), light intensity regulating device (2), be located at the rectangular vessel (3) of the upper end open in housing, the rectangle sample pallet (4) be located in container, the support (5) be located on Housing Base (21), be located on support for the light emitting head (6) to sample irradiation light and the light-receiving head (7) for the reflected light that receives sample; Light intensity regulating device, laser array, light emitting head are electrically connected successively, and light-receiving head is electrically connected with spectrometer; Container and sample tray are made by non-magnet_conductible material, liquid is provided with in described container, described sample tray is suspended on liquid surface, container bottom is provided with several vertical cores (8) of the arrangement in m rank square formation, the equal upward opening of each vertical core and be equipped with location electromagnet (9) in vertical core, location magnet piece is provided with in the middle part of described sample tray, metal column (11) upper end through sample tray lower surface is connected with location magnet piece, and the polarity of the magnetic pole of location electromagnet and magnet piece opposite end, location is contrary;

Each edge of sample tray is equipped with some pieces of traction magnet pieces (12), each side of container is equipped with some pieces of power for traction magnet (13); Light intensity regulating device, spectrometer, each block of location electromagnet and each block of power for traction magnet are all electrically connected with controller.

2. degree of beef freshness pick-up unit according to claim 1, it is characterized in that, motor (14) is equipped with in container below each vertical core, each location electromagnet is connected with the vertical rotating shaft of each motor respectively, location electromagnet is provided with keeper (15), keeper upper end offers M shape groove (16), metal column lower end is provided with the M shape projection (17) corresponding with M shape groove, and each motor is electrically connected with controller.

3. degree of beef freshness pick-up unit according to claim 1, it is characterized in that, described laser array comprises 6 and bundles and the single wavelength laser that is arranged in order of wavelength, and the wavelength of each single wavelength laser is respectively 630nm, 925nm, 534nm, 780nm, 610nm and 730nm.

4. degree of beef freshness pick-up unit according to claim 1, it is characterized in that, described light intensity regulating device comprises data collecting card (18) and power amplifier (19), described data collecting card is provided with the signal input interface for being electrically connected with controller, described data collecting card is electrically connected with the input end of power amplifier, and the output terminal of described power amplifier is connected with the power electric of laser array.

5. the degree of beef freshness pick-up unit according to claim 1 or 2 or 3 or 4, it is characterized in that, support is L-shaped, comprises horizon bar and column; Light emitting head is connected with horizon bar respectively by montant with light-receiving head; Each piece of traction magnet piece is all in bar shaped, and the pole polarity outside each piece of traction magnet piece is identical.

6. be applicable to a detection method for degree of beef freshness pick-up unit according to claim 1, it is characterized in that, comprise the steps:

(6-1) according to CNS GB/T 5009.44-2003, detect the total volatile basic nitrogen TVB-N value of different resting period beef sample, and obtain and m ²the freshness threshold that individual sample detection point is corresponding respectively ${\mathrm{SNR}}_{\mathrm{thre}1},{\mathrm{SNR}}_{\mathrm{thre}1},...,{\mathrm{SNR}}_{{\mathrm{threm}}^2};$

(6-2) sample preparation: choose sheet meat as detected sample from beef to be detected;

(6-3) detect: controller is electrically connected with light intensity regulating device, spectrometer, each block of location electromagnet and each block of power for traction magnet, sample is kept flat on sample tray;

(6-3-1) controller is by being energized and power-off to each each block of location electromagnet and each block of power for traction magnet, and Quality control pallet moves to each vertical core along bow font;

(6-3-2) after metal column inserts a vertical core, the detection light that controller regulates laser array to export by light intensity regulating device, detect light and rise to maximal value MAT from 0 according to sinusoidal curve, then drop to 0 from maximal value MAT according to sinusoidal curve; Detect rear spectrometer and obtain m ²individual detection signal Spect (t);

(6-4) controller is to m ²individual detection signal Spect (t) all does following data processing:

Detection signal Spect (t) is inputted one deck accidental resonance model:

In, controller calculates V (x, t, α) for the first order derivative of x, second derivative and three order derivatives, and makes equation equal 0, obtains two layers of accidental resonance model:

setting noise intensity the critical value calculating A is the critical value of A is substituted in one deck accidental resonance model, and set X ₀(t)=0, sn ₀=0, with quadravalence jade for asking rain Ge Kuta Algorithm for Solving one deck accidental resonance model, obtain $x_{n-1}\left(t\right)=x_n\left(t\right)+1/6[{\left(k_1\right)}_n+(2-\sqrt{2}){\left(k_2\right)}_n+(2+\sqrt{2}){\left(k_3\right)}_n+{\left(k_4\right)}_n],$ n＝0，1，…，N-1

Wherein undetermined coefficient:

(k ₁) _n＝α(αx _n-1(t)) ²-b(αx _n-1(t)) ³+sn _n-1

${\left(k_2\right)}_n=a({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{3})-b{({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{3})}^3+{\mathrm{sn}}_{n-1}$

${\left(k_3\right)}_n=a({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{{\left(k_2\right)}_{n-1}}{3})-b{({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{\sqrt{2}-1}{3}{\left(k_1\right)}_{n-1}+\frac{2-\sqrt{2}}{3}{\left(k_2\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}$

${\left(k_4\right)}_n=a({3\mathrm{\αx}}_{n-1}\left(t\right)+{\left(k_3\right)}_{n-1})-b{({\mathrm{\αx}}_{n-1}\left(t\right)+\frac{\sqrt{2}}{3}{\left(k_2\right)}_{n-1}+\frac{2-\sqrt{2}}{3}{\left(k_3\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}$ Wherein, x _nt n order derivative that () is x (t), sn _n-1the value of n-1 order derivative at t=0 place of S (t), an _n+1the value of n+1 order derivative at t=0 place of S (t), n=0,1 ..., N-1; Obtain x ₁(t), x ₂(t) ..., x _n+1the value of (t);

Controller is to x ₁(t), x ₂(t) ..., x _n+1t () carries out integration, obtain x (t), and obtain x (t) produces accidental resonance moment optimal detection moment time t1 in the double-deck stochastic system of one deck accidental resonance model and two layers of accidental resonance model composition, optimum transient motion acceleration alpha 1, and determine the noise D1 corresponding to t1 and α 1;

Controller utilizes formula calculate the signal to noise ratio (S/N ratio) that double-deck stochastic resonance system exports; Wherein, Δ U=α ²/ 4b; Obtain m ²individual output signal-to-noise ratio ${\mathrm{SNR}}_{\mathrm{thre}1},{\mathrm{SNR}}_{\mathrm{thre}1},...,{\mathrm{SNR}}_{{\mathrm{threm}}^2};$

(6-5) controller utilizes formula calculate the output signal-to-noise ratio error QE corresponding to kth group pivoting angle data _k, wherein, k=1 ..., m ²;

Controller calculates and meets QE _kthe number M of the output signal-to-noise ratio error of≤5% ₁; Controller calculates and meets QE _kthe number M of the output signal-to-noise ratio error of > 5% ₂;

If (6-6) then the fresh judgement of sample made by controller;

If then the stale judgement of sample made by controller;

Otherwise, return step (6-3-1), sample detected again and carries out data processing.

7. the detection method of degree of beef freshness pick-up unit according to claim 1, motor is equipped with in container below each vertical core described, each location electromagnet is connected with the vertical rotating shaft of each motor respectively, location electromagnet is provided with keeper, keeper upper end offers M shape groove, metal column lower end is provided with the M shape projection corresponding with M shape groove, and each motor is electrically connected with controller; It is characterized in that,

Step (6-3-2) is replaced by following step:

After metal column inserts a vertical core, the detection light that controller regulates laser array to export by light intensity regulating device, described detection light rises to maximal value MAT from 0 according to sinusoidal curve, then drops to 0 from maximal value MAT according to sinusoidal curve; In testing process, controller control with metal column insert the corresponding motor of vertical core rotating shaft to drive sample tray to rotate 1 to 2 all, spectrometer obtains detection signal Spect (t).

8. the detection method of degree of beef freshness pick-up unit according to claim 1, is characterized in that, the thickness of described sheet meat is 26 to 68mm.

9. the detection method of degree of beef freshness pick-up unit according to claim 1, is characterized in that, the incident angle of light emitting head is 15 to 60 degree.

10. the detection method of the degree of beef freshness pick-up unit according to claim 6 or 7 or 8 or 9, is characterized in that, the span of MAT is 98 luxs, lux to 210.