CN104251821A - Device and method for detecting freshness of beef - Google Patents

Abstract

The invention discloses a device and method for detecting freshness of beef. The detecting device comprises a light-proof casing, a halogen lamp, a spectrometer, a light intensity adjusting device, and a light emitting head, a bracket and a light receiving device, which are arranged in the casing. The bracket comprises a bottom plate, a sample supporting plate above the bottom plate, a light-passing plate on the sample supporting plate and an L-shaped fixing arm on the edge of the bottom plate; and the L-shaped fixing arm comprises a horizontal plate above the sample supporting plate and a vertical bar passing through the sample supporting plate and fixedly connected with the sample supporting plate, and a vertical extending arm extending to the light-passing plate is positioned on the position of the horizontal plate above the light-passing plate. The invention has the advantages of fast detection, multiple detection points, reliable detection data and high precision.

Description

The pick-up unit of degree of beef freshness and detection method

Technical field

The present invention relates to measurement techniques for quality detection of meat detection technique field, especially relate to a kind of pick-up unit and the detection method that can detect the degree of beef freshness whether beef is corrupt 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 Halogen lamp LED 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 transmitted light of sample, diffuse reflection spectrum or transmitted 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 of pick-up unit and the detection method that can detect the degree of beef freshness whether beef is corrupt accurately and rapidly.

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

A pick-up unit for degree of beef freshness, comprises light tight housing, Halogen lamp LED, spectrometer, light intensity regulating device, is located at light emitting head, support and optical pickup apparatus in housing; Described support comprises base plate, be positioned at sample splint above base plate, be located at the light-passing board on sample splint and be located at the L shape fixed arm on bottom edge; Described L shape fixed arm comprise be positioned at leveling board above sample splint with through sample splint and the montant be fixedly connected with sample splint, the position be positioned at above light-passing board of leveling board is provided with the vertical adjutage extended to light-passing board, leveling board is provided with the first drive motor for driving vertical adjutage to horizontally rotate, and described vertical adjutage bottom is provided with the second drive motor for driving light emitting head to swing back and forth in vertical guide;

Described optical pickup apparatus comprises the support column coaxial with vertical adjutage be located on base plate, be located at the guide rail on support column and be located on guide rail for receiving the light-receiving head of incident light through the transmitted light after sample, described guide rail in and the arc-shaped being the center of circle with the swinging center of light emitting head; Be provided with the 3rd drive motor for driving support column to rotate in described base plate, light-receiving head is provided with the four-wheel drive motor for driving light-receiving head to run in guide rail;

Light intensity regulating device, Halogen lamp LED are connected successively with light emitting head, and light-receiving head is electrically connected with spectrometer, spectrometer and each drive motor are equipped with the signal output port for being electrically connected with computing machine.

Light intensity regulating device of the present invention is for the light intensity of the light source that regulates Halogen lamp LED to send, computing machine controls light emitting head by first, second drive motor and horizontally rotates and rotate on vertical guide, computing machine is horizontally rotated by the 3rd Electric Machine Control support column, catches transmitted light by the 4th Electric Machine Control light-receiving head; Thus the present invention can be detected the multiple points on sample, different incident angles is adopted to irradiate, 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: light beam is through after 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 transmitted 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.

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 transmitted light, thus enable the detection signal obtained symbolize the freshness of beef more accurately.

Therefore, it is fast that the present invention has detection speed, and check point is more, and the reliability and the precision that detect data are higher.

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 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.

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 Halogen lamp LED, thus realize the adjustment to the light intensity of the light source that Halogen lamp LED sends by the power supply controlling Halogen lamp LED, and by the incident light of light emitting head to sample irradiation Strength Changes.

As preferably, described guide rail comprises guiding base plate, be located at guiding plate upper surface and along the arc of guiding base plate to two the spaced grooves extended, described groove floor is provided with the tooth bar arranged at equal intervals; Be provided with bottom described light-receiving head two with the gear of fit depressions; Described four-wheel drive motor is positioned at light-receiving head bottom, and the rotating shaft of four-wheel drive motor is connected with the coupling shaft be located between two gears.The vibrational power flow of guide rail makes light-receiving head can move back and forth in guide rail under the drive of four-wheel drive motor.

As preferably, described guiding base plate also comprises the first curved baffle and second curved baffle relative with the first curved baffle; First arc, the second curved baffle are provided with corresponding guide chute; The coupling shaft two ends of described gear are provided with the outrigger shaft of guide chute for inserting the first arc, the second curved baffle.The setting of the first curved baffle and the second curved baffle, when light-receiving head is moved, stability is better.

As preferably, described drive motor is stepper motor; Support column is connected with base plate by bearing, and vertical adjutage is connected with leveling board by bearing, and light emitting head is connected with vertical adjutage by bearing.

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

(6-1) be preset with the P group pivoting angle data of incoming position to light emitting head on sample and relevant each motor of incident angle in computing machine, the initial rotation angle degree of each motor is 0, and the initial position of light emitting head is vertical state; Setting detects position number i=1;

According to CNS GB/T5009.44-2003, detect the total volatile basic nitrogen TVB-N value of different resting period beef sample, and obtain the freshness threshold SNR corresponding respectively with P group pivoting angle data _thre1, SNR _thre2..., SNR _threp;

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

(6-3) detect: computing machine is electrically connected with spectrometer and each motor, sample is kept flat on light-passing board;

(6-3-1) computing machine controls the first and second drive motor and drives light emitting heads horizontally rotate and swing, light emitting head is radiated on the predetermined irradiation position corresponding to i-th group of pivoting angle data, and makes the 3rd drive motor drive support column and adjutage synchronous axial system;

(6-3-2) after light emitting head reaches predetermined incoming position and incident angle, computing machine controls four-wheel drive driven by motor light-receiving head and moves on guide rail, and observe by spectrometer the light intensity that light-receiving head receives, computing machine be parked in guide rail by four-wheel drive Electric Machine Control light-receiving head with the position corresponding to the maximum of intensity of light;

(6-3-3) computing machine regulates light emitting head output detections light by light intensity regulating device, and described detection light rises to maximal value MAT from 0 according to sinusoidal curve, then drops to 0 from maximal value MAT according to straight line; Spectrometer receives detection signal Spect (t) corresponding with detecting light;

(6-3-4) work as i<P, make i value increase by 1, repeat step (6-3-1) to (6-3-3), obtain P detection signal Spect (t);

(6-4) computing machine all does following data processing to P detection signal Spect (t):

(6-4-1) detection signal Spect (t) is inputted one deck accidental resonance model

In, wherein, V (x, t) is potential function, and x (t) is Brownian movement Particles Moving lopcus function, and a, b are the constant of setting, and ξ (t) is external noise, and D is external noise intensity, and 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

(6-4-2) computer calculate V (x, t) is for the first order derivative of x and second derivative, 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

(6-4-3) 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 $x_{n+1}\left(t\right)=x_n\left(t\right)+1/6[{\left(k_1\right)}_n+(2-\sqrt{2}){\left(k_2\right)}_n+(2+\sqrt{2}){\left(k_3\right)}_n+{\left(k_4\right)}_n];$ And calculate ${\left(k_1\right)}_n=4({\mathrm{ax}}_{n-1}\left(t\right)-{\mathrm{bx}}_{n-1}^3\left(t\right)+{\mathrm{sn}}_{n-1}),$ ${\left(k_2\right)}_n=4[a(x_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{2})-b{(x_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{2})}^3+{\mathrm{sn}}_{n-1}],$ ${\left(k_3\right)}_n=4[a(x_{n-1}\left(t\right)+\frac{{\left(k_2\right)}_{n-1}}{2})-b{(x_{n-1}\left(t\right)+\frac{\sqrt{2}-1}{2}{\left(k_1\right)}_{n-1}+\frac{2-\sqrt{2}}{2}{\left(k_2\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}],$

${\left(k_4\right)}_n=4[a(x_{n-1}\left(t\right)+{\left(k_3\right)}_{n-1})-b{(x_{n-1}\left(t\right)-\frac{\sqrt{2}}{2}{\left(k_2\right)}_{n-1}+\frac{2+\sqrt{2}}{2}{\left(k_3\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}];$

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);

(6-4-4) computing machine is to x ₁(t), x ₂(t) ..., x _n+1t () carries out integration, obtain x (t), and obtains x (t) produces accidental resonance moment position x in the double-deck stochastic system of one deck accidental resonance model and two layers of accidental resonance model composition _mvalue and x _mcorresponding resonance moment t ₁and and t ₁corresponding noise D ₁, D ₁for the value of in D;

(6-4-5) 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 P output signal-to-noise ratio SNR ₁, SNR ₂..., SNR _p;

(6-5) computing machine utilizes formula calculate the output signal-to-noise ratio error QE corresponding to i-th group of pivoting angle data _i, wherein, i=1 ..., P;

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

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

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

Otherwise computing machine makes i value be 1, return step (6-3-1), sample is detected again and carries out data processing.

As preferably, the thickness of described sheet meat is 35 to 150mm.

As preferably, incident angle is 0 to 45 degree.

As preferably, the span of MAT is 100 luxs, lux to 200.

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 theory diagram of the present invention;

Fig. 3 is a kind of cut-open view of guide rail of the present invention;

Fig. 4 is a kind of vertical view of guide rail 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.

In figure: Halogen lamp LED 1, spectrometer 2, light intensity regulating device 3, support 4, optical pickup apparatus 5, base plate 6, sample splint 7, net 8 placed by sample, L shape fixed arm 9, leveling board 10, montant 11, vertical adjutage 12, first drive motor 13, second drive motor 14, support column 15, guide rail 16, light-receiving head 17, 3rd drive motor 18, four-wheel drive motor 19, data collecting card 20, power amplifier 21, computing machine 22, light emitting head 23, guiding base plate 161, groove 162, gear 163, coupling shaft 164, first curved baffle 165, second curved baffle 166, guide chute 167, outrigger shaft 168, third gear plate 169, fourth gear plate 170.

Embodiment

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

Embodiment is as shown in Figure 1 and Figure 2 a kind of pick-up unit of degree of beef freshness, and pick-up unit comprises light tight housing, Halogen lamp LED 1, spectrometer 2, light intensity regulating device 3, is located at the light emitting head 23 in housing, support 4 and optical pickup apparatus 5; Support comprises base plate 6, be positioned at sample splint 7 above base plate, be located at the light-passing board 8 on sample splint and be located at the L shape fixed arm 9 on bottom edge; L shape fixed arm comprise be positioned at leveling board 10 above sample splint with through sample splint and the montant 11 be fixedly connected with sample splint, the position be positioned at above light-passing board of leveling board is provided with the vertical adjutage 12 extended to light-passing board, leveling board is provided with the first drive motor 13 for driving vertical adjutage to horizontally rotate, and vertical adjutage bottom is provided with the second drive motor 14 for driving light emitting head to swing back and forth in vertical guide;

As shown in Figure 1, Figure 3, optical pickup apparatus comprises the support column 15 coaxial with vertical adjutage be located on base plate, be located at the guide rail 16 on support column and be located on guide rail for receiving the light-receiving head 17 of incident light through the transmitted light after sample, guide rail in and the arc-shaped being the center of circle with the swinging center of light emitting head; Be provided with the 3rd drive motor 18 for driving support column to rotate in base plate, light-receiving head is provided with the four-wheel drive motor 19 for driving light-receiving head to run in guide rail;

Light intensity regulating device, Halogen lamp LED are connected successively with light emitting head, and light-receiving head is electrically connected with spectrometer, spectrometer and each drive motor are equipped with the signal output port for being electrically connected with computing machine 22.

As shown in Figure 2, light intensity regulating device comprises N1-6259 data collecting card 20 and power amplifier 21, 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.

As shown in Fig. 1, Fig. 3, Fig. 4, guide rail comprises guiding base plate 161, is located at the arc of the plate upper surface base plate and lead in edge that leads to two the spaced grooves 162 extended, and groove floor is provided with the tooth bar arranged at equal intervals; Be provided with bottom light-receiving head two with the gear 163 of fit depressions; Four-wheel drive motor is positioned at light-receiving head bottom, and the rotating shaft of four-wheel drive motor is connected with the coupling shaft 164 be located between two gears, is also provided with third gear plate 169 and fourth gear plate 170.

Guiding base plate also comprises the first curved baffle 165 and second curved baffle 166 relative with the first curved baffle; First arc, the second curved baffle are provided with corresponding guide chute 167; The coupling shaft two ends of gear are provided with the outrigger shaft 168 of guide chute for inserting the first arc, the second curved baffle.

Drive motor is stepper motor; Support column is connected with base plate by bearing, and vertical adjutage is connected with leveling board by bearing, and light emitting head is connected with vertical adjutage by bearing; Light-passing board is the quartz glass plate of 0.4mm to 1mm.Adopt the quartz glass plate of 0.4mm as light-passing board in the present embodiment.

As shown in Figure 6, a kind of detection method of pick-up unit of degree of beef freshness, comprises the steps:

Be preset with 8 groups of pivoting angle data of incoming position to light emitting head on sample and relevant each motor of incident angle in computing machine, the initial rotation angle degree of each motor is 0, and the initial position of light emitting head is vertical state; Setting detects position number i=1;

According to CNS GB/T5009.44-2003, 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 groups of pivoting angle data _thrd=-75.45dB, SNR _thre2=-68.57dB, SNR _thre3=-62.37dB, SNR _thre4=-55.32dB, SNR _thre5=-48.41dB, SNR _thre6=-41.93dB, SNR _thre7=-34.51dB, SNR _thre8=-30.65dB.

Freshness threshold SNR _thre1, SNR _thre2..., SNR _{th curses 8}the 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 and 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 100 to detect to 300 in the sample of this day, 8 SNR obtained are freshness threshold SNR _thre1, SNR _thre2..., SNR _thre8.

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 _thre2..., SNR _thre8, the freshness detecting the beef stored under the same conditions can only be used for.

Step 100, sample preparation: take out the sheet meat of 80mm as detected sample from beef to be detected;

Step 200, detects: be electrically connected with spectrometer and each motor by computing machine, kept flat by sample on light-passing board;

Step 210, computing machine controls the first and second drive motor and drives light emitting head horizontally rotate and swing, light emitting head is radiated on the predetermined irradiation position corresponding to i-th group of pivoting angle data, and makes the 3rd drive motor drive support column and adjutage synchronous axial system;

Step 220, after light emitting head reaches predetermined incoming position and incident angle, computing machine controls four-wheel drive driven by motor light-receiving head and moves on guide rail, and observe by spectrometer the light intensity that light-receiving head receives, computing machine be parked in guide rail by four-wheel drive Electric Machine Control light-receiving head with the position corresponding to the maximum of intensity of light;

Step 230, computing machine regulates light emitting head output detections light by light intensity regulating device, as shown in Figure 5, within 10 second time, detected light rise to maximal value 200 lux from 0 according to sinusoidal curve, then within 10 second time, dropped to 0 from maximal value 200 lux according to straight line; Spectrometer receives detection signal Spect (t) corresponding with detecting light;

Step 240, works as i<8, makes i value increase by 1, repeats step 210 to 230, obtains 8 detection signals Spect (t);

Step 300, computing machine all does following data processing to 8 detection signals Spect (t):

Step 310, inputs one deck accidental resonance model by detection signal Spect (t)

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

Step 320, computer calculate V (x, t) for the first order derivative of x and second derivative, 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

Step 330, substitutes into the critical value of A in one deck accidental resonance model, and sets X ₀(t)=0, sn ₀=0, with quadravalence jade for asking rain Ge Kuta Algorithm for Solving one deck accidental resonance model, obtain $x_{n+1}\left(t\right)=x_n\left(t\right)+1/6[{\left(k_1\right)}_n+(2-\sqrt{2}){\left(k_2\right)}_n+(2+\sqrt{2}){\left(k_3\right)}_n+{\left(k_4\right)}_n];$ And calculate ${\left(k_1\right)}_n=4({\mathrm{ax}}_{n-1}\left(t\right)-{\mathrm{bx}}_{n-1}^3\left(t\right)+{\mathrm{sn}}_{n-1}),$ ${\left(k_2\right)}_n=4[a(x_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{2})-b{(x_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{2})}^3+{\mathrm{sn}}_{n-1}],$ ${\left(k_3\right)}_n=4[a(x_{n-1}\left(t\right)+\frac{{\left(k_2\right)}_{n-1}}{2})-b{(x_{n-1}\left(t\right)+\frac{\sqrt{2}-1}{2}{\left(k_1\right)}_{n-1}+\frac{2-\sqrt{2}}{2}{\left(k_2\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}],$ ${\left(k_4\right)}_n=4[a(x_{n-1}\left(t\right)+{\left(k_3\right)}_{n-1})-b{(x_{n-1}\left(t\right)-\frac{\sqrt{2}}{2}{\left(k_2\right)}_{n-1}+\frac{2+\sqrt{2}}{2}{\left(k_3\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}];$

Wherein, x _nt n order derivative that () is x (t), sn _nthe value of n 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);

Step 340, computing machine is to x ₁(t), x ₂(t) ..., x _n+1t () carries out integration, obtain x (t), and obtains x (t) produces accidental resonance moment position x in the double-deck stochastic system of one deck accidental resonance model and two layers of accidental resonance model composition _mvalue and x _mcorresponding resonance moment t ₁, and and t ₁corresponding noise D 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.

Step 350, 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 8 output signal-to-noise ratio SNR ₁, SNR ₂..., SNR ₈;

Step 400, the error of calculation:

Computing machine utilizes formula calculate the output signal-to-noise ratio error QE corresponding to i-th group of pivoting angle data _i, wherein, i= ₁..., 8;

Computer calculate meets QE _ithe number M of the output signal-to-noise ratio error of≤5% ₁; Computer calculate meets QE _ithe 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 computing machine;

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

Otherwise computing machine makes i value be 1, returns step 210, sample is detected again and carries out data processing.

M in the present embodiment ₁=7, therefore, the fresh judgement of sample made by computing machine.

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 (9)

1. the pick-up unit of a degree of beef freshness, it is characterized in that, described pick-up unit comprises light tight housing, Halogen lamp LED (1), spectrometer (2), light intensity regulating device (3), is located at the light emitting head (23) in housing, support (4) and optical pickup apparatus (5); The L shape fixed arm (9) that described support comprises base plate (6), be positioned at sample splint (7) above base plate, be located at the light-passing board (8) on sample splint and be located on bottom edge; Described L shape fixed arm comprise be positioned at leveling board (10) above sample splint with through sample splint and the montant (11) be fixedly connected with sample splint, the position be positioned at above light-passing board of leveling board is provided with the vertical adjutage (12) extended to light-passing board, leveling board is provided with the first drive motor (13) for driving vertical adjutage to horizontally rotate, and described vertical adjutage bottom is provided with the second drive motor (14) for driving light emitting head to swing back and forth in vertical guide;

Described optical pickup apparatus comprises the support column (15) coaxial with vertical adjutage be located on base plate, be located at the guide rail (16) on support column and be located on guide rail for receiving the light-receiving head (17) of incident light through the transmitted light after sample, described guide rail in and the arc-shaped being the center of circle with the swinging center of light emitting head; Be provided with the 3rd drive motor (18) for driving support column to rotate in described base plate, light-receiving head is provided with the four-wheel drive motor (19) for driving light-receiving head to run in guide rail;

Light intensity regulating device, Halogen lamp LED are connected successively with light emitting head, and light-receiving head is electrically connected with spectrometer, spectrometer and each drive motor are equipped with the signal output port for being electrically connected with computing machine (22).

2. the pick-up unit of degree of beef freshness according to claim 1, it is characterized in that, described light intensity regulating device comprises data collecting card (20) and power amplifier (21), 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.

3. the pick-up unit of degree of beef freshness according to claim 1, it is characterized in that, described guide rail comprises guiding base plate (161), is located at the arc of the plate upper surface base plate and lead in edge that leads to two the spaced grooves (162) extended, and described groove floor is provided with the tooth bar arranged at equal intervals; Be provided with bottom described light-receiving head two with the gear (163) of fit depressions; Described four-wheel drive motor is positioned at light-receiving head bottom, and the rotating shaft of four-wheel drive motor is connected with the coupling shaft be located between two gears (164).

4. the pick-up unit of degree of beef freshness according to claim 3, is characterized in that, described guiding base plate also comprises the first curved baffle (165) and second curved baffle (166) relative with the first curved baffle; First arc, the second curved baffle are provided with corresponding guide chute (167); The coupling shaft two ends of described gear are provided with the outrigger shaft (168) of guide chute for inserting the first arc, the second curved baffle.

5. the pick-up unit of the degree of beef freshness according to claim 1 or 2 or 3 or 4, it is characterized in that, described drive motor is stepper motor; Support column is connected with base plate by bearing, and vertical adjutage is connected with leveling board by bearing, and light emitting head is connected with vertical adjutage by bearing.

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

(6-1) be preset with the P group pivoting angle data of incoming position to light emitting head on sample and relevant each motor of incident angle in computing machine, the initial rotation angle degree of each motor is 0, and the initial position of light emitting head is vertical state; Setting detects position number i=1;

According to CNS GB/T5009.44-2003, detect the total volatile basic nitrogen TVB-N value of different resting period beef sample, and obtain the freshness threshold SNR corresponding respectively with P group pivoting angle data _thre1, SNR _thre2..., SNR _threp;

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

(6-3) detect: computing machine is electrically connected with spectrometer and each motor, sample is kept flat on light-passing board;

(6-3-1) computing machine controls the first and second drive motor and drives light emitting heads horizontally rotate and swing, light emitting head is radiated on the predetermined irradiation position corresponding to i-th group of pivoting angle data, and makes the 3rd drive motor drive support column and adjutage synchronous axial system;

(6-3-2) after light emitting head reaches predetermined incoming position and incident angle, computing machine controls four-wheel drive driven by motor light-receiving head and moves on guide rail, and observe by spectrometer the light intensity that light-receiving head receives, computing machine be parked in guide rail by four-wheel drive Electric Machine Control light-receiving head with the position corresponding to the maximum of intensity of light;

(6-3-3) computing machine regulates light emitting head output detections light by light intensity regulating device, and described detection light rises to maximal value MAT from 0 according to sinusoidal curve, then drops to 0 from maximal value MAT according to straight line; Spectrometer receives detection signal Spect (t) corresponding with detecting light;

(6-3-4) work as i<P, make i value increase by 1, repeat step (6-3-1) to (6-3-3), obtain P detection signal Spect (t);

(6-4) computing machine all does following data processing to P detection signal Spect (t):

(6-4-1) detection signal Spect (t) is inputted one deck accidental resonance model

In, wherein, V (x, t) is potential function, and x (t) is Brownian movement Particles Moving lopcus function, and a, b are the constant of setting, and ξ (t) is external noise, and D is external noise intensity, and 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

(6-4-2) computer calculate V (x, t) is for the first order derivative of x and second derivative, 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

(6-4-3) 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 $x_{n+1}\left(t\right)=x_n\left(t\right)+1/6[{\left(k_1\right)}_n+(2-\sqrt{2}){\left(k_2\right)}_n+(2+\sqrt{2}){\left(k_3\right)}_n+{\left(k_4\right)}_n];$ And calculate ${\left(k_1\right)}_n=4({\mathrm{ax}}_{n-1}\left(t\right)-{\mathrm{bx}}_{n-1}^3\left(t\right)+{\mathrm{sn}}_{n-1}),$ ${\left(k_2\right)}_n=4[a(x_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{2})-b{(x_{n-1}\left(t\right)+\frac{{\left(k_1\right)}_{n-1}}{2})}^3+{\mathrm{sn}}_{n-1}],$ ${\left(k_3\right)}_n=4[a(x_{n-1}\left(t\right)+\frac{{\left(k_2\right)}_{n-1}}{2})-b{(x_{n-1}\left(t\right)+\frac{\sqrt{2}-1}{2}{\left(k_1\right)}_{n-1}+\frac{2-\sqrt{2}}{2}{\left(k_2\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}],$ ${\left(k_4\right)}_n=4[a(x_{n-1}\left(t\right)+{\left(k_3\right)}_{n-1})-b{(x_{n-1}\left(t\right)-\frac{\sqrt{2}}{2}{\left(k_2\right)}_{n-1}+\frac{2+\sqrt{2}}{2}{\left(k_3\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}];$

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);

(6-4-4) computing machine is to x ₁(t), x ₂(t) ..., x _n+1t () carries out integration, obtain x (t), and obtains x (t) produces accidental resonance moment position x in the double-deck stochastic system of one deck accidental resonance model and two layers of accidental resonance model composition _mvalue and x _mcorresponding resonance moment t ₁and and t ₁corresponding noise D ₁, D ₁for the value of in D;

(6-4-5) 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 P output signal-to-noise ratio SNR ₁, SNR ₂..., SNR _p;

(6-5) computing machine utilizes formula calculate the output signal-to-noise ratio error QE corresponding to i-th group of pivoting angle data _i, wherein, i=1 ..., P;

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

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

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

Otherwise computing machine makes i value be 1, return step (6-3-1), sample is detected again and carries out data processing.

7. the detection method of the pick-up unit of degree of beef freshness according to claim 6, is characterized in that, the thickness of described sheet meat is 35 to 150mm.

8. the detection method of the pick-up unit of degree of beef freshness according to claim 6, is characterized in that, incident angle is 0 to 45 degree.

9. the detection method of the pick-up unit of the degree of beef freshness according to claim 6 or 7 or 8, is characterized in that, the span of MAT is 100 luxs, lux to 200.