CN104374708A - 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 comprises an opaque housing, a halogen lamp, a spectrometer, a lifting platform arranged in the housing, a rectangular container which is arranged on the lifting platform and is provided with an opening at the upper end, a rectangular sample tray arranged in the container, a cross bar arranged in the housing, a light emitting head which is arranged on the cross bar and is used for irradiating light to a sample, a light receiving head for receiving reflected light of the sample, and a distance measuring sensor for measuring distance between the cross bar and the sample tray; and the beef freshness detection device has the advantages of fast detection speed, more detection points, and higher detection data reliability and precision.

Description

A kind of 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, Halogen lamp LED, spectrometer, be located at the hoistable platform in housing, be located at the rectangular vessel of the upper end open on hoistable platform, be located at the rectangle sample pallet in container, be located at the cross bar in housing, be located on cross bar for the light emitting head to sample irradiation light, for receiving the light-receiving head of the reflected light of sample and the distance measuring sensor for detecting spacing between cross bar and sample tray;

Halogen lamp LED, light emitting head are electrically connected, and light-receiving head is electrically connected with spectrometer, and hoistable platform is connected with the first motor being located at housing bottom by screw mandrel; 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 the vertical core that several are the matrix arrangement of m rank, 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;

Sample tray outward flange is provided with some pieces of traction magnet pieces, and container side is provided with some blocks of power for traction magnet; Distance measuring sensor, spectrometer, each piece of location magnet piece, each block of power for traction magnet and the first motor are equipped with the signal port for being electrically connected with computing machine.

The setting of each vertical core is used for positioning sample tray, and when sample tray moves to different vertical core places, light emitting head can be irradiated to the difference on sample respectively, thus pick-up unit of the present invention can detect the multiple points on sample.

Gauged distance scope is provided with in advance in computing machine, distance measuring sensor is for detecting spacing between cross bar and sample tray, when amount of liquid is in critical field, when the distance between cross bar and sample tray is also within the scope of gauged distance, reflected light can enter in light-receiving head; When amount of liquid is more or less, incident light irradiates less than on the predetermined point of sample, and the direction of reflected light can change, and reflected light cannot enter in light-receiving head; Therefore, when between the cross bar detected and sample tray, spacing is not within the scope of gauged distance, the rotating shaft that computing machine can control the first motor drives screw mandrel to rotate, thus hoistable platform is moved up and down, thus guarantees normal detection.

Light detects the principle of 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, 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, quantity of information is not enriched, and accurately determining of detection is lower.

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, the second motor is equipped with in container below each vertical core, each location electromagnet is connected with the vertical rotating shaft of each the second motor respectively, each location electromagnet is equipped with keeper, each keeper upper end offers x connected in star, metal column lower end is provided with the x shape projection corresponding with x connected in star, and each second motor is provided with the signal port for being electrically connected with computing machine.Metal column is provided with spring, and keeper adopts metal material to make.

Second motor horizontally rotates for driving location electromagnet, in the process rotated, x shape projection can embed in x connected in star, thus drives sample tray to horizontally rotate, then in the testing process be located by connecting with this vertical core, detection be multiple continuous print point on sample.The sample message comprised in the detection signal obtained is more, and it is more accurate to detect.

As preferably, also comprise light intensity regulating device, 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 computing machine, 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 Halogen lamp LED.

Light intensity regulating device of the present invention is for the light intensity of the light source that regulates laser array to send, 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.

Computing machine 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, described screw mandrel upper end is connected with hoistable platform by bearing, and screw mandrel lower end is connected with housing by the eyelets of lower end closed, and eyelets is connected with wire rod thread.

As preferably, light emitting head is connected with cross 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

(6-2) distance adjustment: distance measuring sensor, the first motor are electrically connected with computing machine respectively, distance measuring sensor detects the spacing between cross bar and sample tray, computing machine by the spacing that detects compared with the gauged distance scope preset, and rotate according to the output control first driven by motor screw mandrel compared, thus the spacing between cross bar and sample tray is made to be positioned at gauged distance scope;

(6-3) sample preparation: choose sheet meat as detected sample from beef to be detected;

(6-4) detect: controller is electrically connected with spectrometer, each block of location electromagnet and each block of power for traction magnet, sample is kept flat on sample tray;

(6-4-1) 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;

After metal column inserts a vertical core, computer controlled Halogen lamp LED processed and light emitting head are to sample irradiation utilizing emitted light, and light-receiving head receives reflected light, and spectrometer receives detection signal Spect (t);

(6-5) computing machine 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, computer calculate 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 D=0, spect (t)=0, N (t)=0; 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＝a(αx _n-1(t)) ²b(αx _n-1(t)) ³+sn _n-1

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

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

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

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);

Computing machine 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;

Computing machine utilizes formula calculate the signal to noise ratio (S/N ratio) that double-deck stochastic resonance system exports; Wherein, Δ U=a ²/ 4b; Obtain m ²individual output signal-to-noise ratio

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

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

If (6-7) then the fresh judgement of sample made by computing machine;

If then the stale judgement of sample made by computing machine;

Otherwise, return step (6-4-1), sample detected again and carries out data processing.

As preferably, the second motor is equipped with in container below each vertical core described, each location electromagnet is connected with the vertical rotating shaft of each the second motor respectively, each location electromagnet is equipped with keeper, each keeper upper end all offers x connected in star, metal column lower end is provided with the x shape projection corresponding with x connected in star, and each second motor is provided with the signal port for being electrically connected with computing machine;

In the testing process of (6-4-1), the rotating shaft that computing machine controls the motor corresponding with the vertical core that metal column inserts drives sample tray to rotate for 1 to 2 week.

As preferably, describedly also comprise light intensity regulating device, 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 computing machine, 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 Halogen lamp LED; Step (6-4-1) is replaced by following step:

After metal column inserts a vertical core, the detection light that controller regulates Halogen lamp LED 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.

As preferably, the thickness of described sheet meat is 33 to 68mm.

As preferably, the incident angle of light emitting head is 15 to 60 degree; The span of MAT is 100 luxs, lux to 220.

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 container of the present invention and support;

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 the present invention;

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: Halogen lamp LED 1, spectrometer 2, hoistable platform 3, container 4, sample tray 5, cross bar 6, light emitting head 7, light-receiving head 8, distance measuring sensor 9, vertical core 10, location electromagnet 12, metal column 13, power for traction magnet 14, second motor 15, keeper 16, x connected in star 17, x shape projection 18, computing machine 19, light intensity regulating device 20, data collecting card 21, power amplifier 22, spring 23, first motor 24, traction magnet piece 25, housing 26.

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 a kind of degree of beef freshness pick-up unit, comprise light tight housing 26, Halogen lamp LED 1, spectrometer 2, be located at the hoistable platform 3 in housing, be located at the rectangular vessel 4 of the upper end open on hoistable platform, be located at the rectangle sample pallet 5 in container, be located at the cross bar 6 in housing, be located on cross bar for the light emitting head 7 to sample irradiation light, for receiving light-receiving head 8 and the distance measuring sensor 9 for detecting spacing between cross bar and sample tray as shown in Figure 4 of the reflected light of sample;

As shown in Figure 4, Halogen lamp LED, light emitting head are electrically connected, and light-receiving head is electrically connected with spectrometer, and hoistable platform is connected with the first motor 24 being located at housing bottom by screw mandrel; Container and sample tray are all made of plastics, water is filled in container, sample tray is suspended on liquid surface, container bottom is provided with 16 vertical cores 10 in 4 rank matrix arrangements, the equal upward opening of each vertical core and be equipped with location electromagnet 12 in vertical core, be provided with location magnet piece in the middle part of sample tray, metal column 13 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;

As shown in Figure 2, sample tray outward flange is provided with 16 pieces of traction magnet pieces 25, and container side is provided with 16 blocks of power for traction magnet 14; Traction magnet piece can be identical with the quantity of power for traction magnet, also can be different, moves as long as enough draw sample tray.

As shown in Figure 4, the first motor, distance measuring sensor, spectrometer, each piece of location magnet piece and each block of power for traction magnet are all electrically connected with computing machine 19.

As shown in Figure 6, a kind of detection method of 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; Gauged distance scope 15.30 centimetres to 15.40 centimetres is provided with in computing machine;

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 8 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 SNR to the beef sample stored in certain temperature, pressure and humidity _thre1, SNR _thre1..., SNR _thre16, the freshness detecting the beef stored under the same conditions can only be used for.

Step 100, distance adjustment: distance measuring sensor, the first motor are electrically connected with computing machine respectively, distance measuring sensor detects the spacing between cross bar and sample tray, computing machine by the spacing that detects compared with the gauged distance scope preset, and rotate according to the output control first driven by motor screw mandrel compared, thus the spacing between cross bar and sample tray is made to be positioned at gauged distance scope;

Step 200, sample preparation: choose the thick sheet meat of 40mm as detected sample from beef to be detected;

Step 300, detects: be electrically connected with spectrometer, each block of location electromagnet and each block of power for traction magnet by controller, kept flat by sample on sample tray;

Step 310, 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 the order in Fig. 1 shown in arrow in bow font;

After metal column inserts a vertical core, computer controlled Halogen lamp LED processed and light emitting head are to sample irradiation utilizing emitted light, and light-receiving head receives reflected light, and spectrometer receives detection signal Spect (t);

Step 400, data processing:

Computing machine all does following data processing to 16 detection signals Spect (t):

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

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

Setting noise intensity D=0, spect (t)=0, N (t)=0; 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

And calculate undetermined coefficient:

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

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

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

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

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);

Computing machine 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.

Computing machine utilizes formula calculate the signal to noise ratio (S/N ratio) that double-deck stochastic resonance system exports; Wherein, Δ U=a ²/ 4b; Obtain 16 output signal-to-noise ratio SNR ₁, SNR ₂..., SNR ₁₆;

Step 500, error calculation:

Computing machine utilizes formula calculate the output signal-to-noise ratio error QE corresponding to kth group pivoting angle data _k, wherein, k=1 ..., 16;

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

Step 600, judges:

If then the fresh judgement of sample made by computing machine;

If then the stale judgement of sample made by computing machine;

Otherwise, return step 310, sample detected again and carries out data processing.

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

Embodiment 2

In embodiment 2,

As shown in Figure 3, the second motor 15 is equipped with in container below each vertical core, each location electromagnet is connected with the vertical rotating shaft of each the second motor respectively, each location electromagnet is equipped with keeper 16, each keeper upper end all offers x connected in star 17, metal column lower end is provided with the x shape projection 18 corresponding with x connected in star, and each second motor is provided with the signal port for being electrically connected with computing machine 19.Metal column is provided with spring 23.

As shown in Figure 4, also comprise light intensity regulating device 20, light intensity regulating device comprises data collecting card 21 and power amplifier 22, data collecting card is provided with the signal input interface for being electrically connected with computing machine, 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 Halogen lamp LED.

Step 310 is replaced by following step:

After metal column inserts a vertical core, the detection light that controller regulates Halogen lamp LED to export by light intensity regulating device, as shown in Figure 5, detect light and rise to maximal value 200 lux from 0 according to sinusoidal curve, then drop to 0 from maximal value 200 lux according to sinusoidal curve; In testing process, the rotating shaft that computing machine controls second motor corresponding with the vertical core that metal column inserts drives sample tray to rotate 1 week.

Other result 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 (26), Halogen lamp LED (1), spectrometer (2), be located at the hoistable platform (3) in housing, be located at the rectangular vessel (4) of the upper end open on hoistable platform, be located at the rectangle sample pallet (5) in container, be located at the cross bar (6) in housing, be located on cross bar for the light emitting head (7) to sample irradiation light, for receiving the light-receiving head (8) of the reflected light of sample and the distance measuring sensor (9) for detecting spacing between cross bar and sample tray,

Halogen lamp LED, light emitting head are electrically connected, and light-receiving head is electrically connected with spectrometer, and hoistable platform is connected with the first motor (24) being located at housing bottom by screw mandrel; 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 the vertical core that several are the matrix arrangement of m rank, each vertical core (10) all upward openings and be equipped with location electromagnet (12) in vertical core, location magnet piece is provided with in the middle part of described sample tray, metal column (13) 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;

Sample tray outward flange is provided with some pieces of traction magnet pieces (25), and container side is provided with some pieces of power for traction magnet (14); Distance measuring sensor, spectrometer, each piece of location magnet piece, each block of power for traction magnet and the first motor are equipped with the signal port for being electrically connected with computing machine (19).

2. degree of beef freshness pick-up unit according to claim 1, it is characterized in that, the second motor (15) is equipped with in container below each vertical core, each location electromagnet is connected with the vertical rotating shaft of each the second motor respectively, each location electromagnet is equipped with keeper (16), each keeper upper end offers x connected in star (17), metal column lower end is provided with the x shape projection (18) corresponding with x connected in star, each second motor is equipped with the signal port for being electrically connected with computing machine.

3. degree of beef freshness pick-up unit according to claim 1, it is characterized in that, also comprise light intensity regulating device (20), described light intensity regulating device comprises data collecting card (21) and power amplifier (22), described data collecting card is provided with the signal input interface for being electrically connected with computing machine, 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 Halogen lamp LED.

4. degree of beef freshness pick-up unit according to claim 1, is characterized in that, described screw mandrel upper end is connected with hoistable platform by bearing, and screw mandrel lower end is connected with housing by the eyelets of lower end closed, and eyelets is connected with wire rod thread.

5. the degree of beef freshness pick-up unit according to claim 1 or 2 or 3 or 4, it is characterized in that, light emitting head is connected with cross 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

(6-2) distance adjustment: distance measuring sensor, the first motor are electrically connected with computing machine respectively, distance measuring sensor detects the spacing between cross bar and sample tray, computing machine by the spacing that detects compared with the gauged distance scope preset, and rotate according to the output control first driven by motor screw mandrel compared, thus the spacing between cross bar and sample tray is made to be positioned at gauged distance scope;

(6-3) sample preparation: choose sheet meat as detected sample from beef to be detected;

(6-4) detect: controller is electrically connected with spectrometer, each block of location electromagnet and each block of power for traction magnet, sample is kept flat on sample tray;

(6-4-1) 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;

After metal column inserts a vertical core, computer controlled Halogen lamp LED processed and light emitting head are to sample irradiation utilizing emitted light, and light-receiving head receives reflected light, and spectrometer receives detection signal Spect (t);

(6-5) computing machine 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, computer calculate 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 D=0, spect (t)=0, N (t)=0; 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＝a(αx _n-1(t)) ²-b(αx _n-1(t)) ³+sn ^n-1

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

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

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

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);

Computing machine 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;

Computing machine utilizes formula calculate the signal to noise ratio (S/N ratio) that double-deck stochastic resonance system exports; Wherein, Δ U=a ²/ 4b; Obtain m ²individual output signal-to-noise ratio

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

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

If (6-7) then the fresh judgement of sample made by computing machine;

If then the stale judgement of sample made by computing machine;

Otherwise, return step (6-4-1), sample detected again and carries out data processing.

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

In the testing process of (6-4-1), computing machine control with metal column insert the second corresponding motor of vertical core rotating shaft to drive sample tray to rotate 1 to 2 all.

8. the detection method of degree of beef freshness pick-up unit according to claim 1, describedly also comprise light intensity regulating device, 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 computing machine, 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 Halogen lamp LED; It is characterized in that, step (6-4-1) is replaced by following step:

After metal column inserts a vertical core, the detection light that controller regulates Halogen lamp LED to export by light intensity regulating device, makes described detection light rise to maximal value MAT from 0 according to sinusoidal curve, then drops to 0 from maximal value MAT according to sinusoidal curve.

9. 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 33 to 68mm.

10. 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; The span of MAT is 100 luxs, lux to 220.