CN104089889B - Beef freshness detection system and method - Google Patents

Abstract

The invention relates to a beef freshness detection system and detection method to solve the problems of subjective and inaccurate detection of beef freshness and complex detection process of detection equipment in the prior art. The system comprises a seat body, the seat body is provided with a bracket, and an irradiation light source is arranged above the bracket. The irradiation light source is rotatably connected to an adjustment mechanism for adjusting the position of the irradiation light source, and the adjustment mechanism is installed on the seat body. A receiving mechanism is disposed below the bracket, and a control unit is disposed in the seat body and is in connection with the irradiation light source, the adjustment mechanism and the receiving mechanism. By analyzing sample reflection or transmission spectrum data, the beef freshness can be judged. By adopting the spectrum detection mode, nondestructive detection can be carried out on samples. The device structure is simple, the operation is fast and simple, and the detection data are accurate.

Description

A kind of degree of beef freshness detecting system and method

Technical field

The present invention relates to a kind of field of food detection, especially relate to a kind of simple in construction, operate fast and convenient, detection standard True degree of beef freshness detecting system, and the detection method of this system.

Background technology

Consumption of meat is always an important component part of food consumption, and beef is that consumers in general's ratio is preferable Food.In recent years, the transformation of people's philosophy of life, health perception constantly strengthens, and quality and sanitary condition to meat product are wanted Ask increasingly stricter, the safety of meat product, concerns life security and the social stability of common people, controls meat product quality and exist Daily life just become more and more important.At present the detection technique of degree of beef freshness there are organoleptic detection, Physico-chemical tests etc..Sense Official's detection often by evaluating the experience of expert, psychology is affected with the factor such as physiology, different teacher of the evaluating due to its have a liking for, feelings Thread, sex and sensory acuity etc. affect, it may be difficult to obtaining consistent evaluation result, therefore the accuracy of evaluation result is past Toward being difficult to ensure that.Physico-chemical tests needs a series of equipment and device to complete, and process is complicated, and the detection time is long, and equipment is the most complicated. Some scholars are also had to develop gas-chromatography detection method the most in recent years, although detection sensitivity is also fine, but this detection side Method damages.It is desirable to have a kind of can the equipment of the cold fresh degree of beef freshness of Non-Destructive Testing quick, easy, accurate and side Method, in order to the most in an orderly manner the beef of storage is detected, to guarantee the safety of beef food.

Summary of the invention

It is inaccurate that the present invention mainly solves, in prior art, degree of beef freshness detection is existed subjectivity, and there is detection The problem that device detection procedure is complicated, it is provided that a kind of simple in construction, operate fast and convenient, detect degree of beef freshness inspection accurately Examining system.

Present invention also offers that a kind of operation is fast and convenient, detect degree of beef freshness detection method accurately.

The above-mentioned technical problem of the present invention is mainly addressed by following technical proposals: a kind of degree of beef freshness inspection Examining system, including pedestal, is provided with the bracket for placing sample on pedestal, is provided above radiation source at bracket, institute Stating radiation source to be rotatably connected on the guiding mechanism adjusting radiation source position, guiding mechanism is arranged on pedestal, at bracket Lower section is provided with receiving mechanism, the present internal control unit that arranges, control unit and radiation source, adjusting pole, receiving mechanism It is connected；

Radiation source: electromagnetic radiation is detected light beam, and can receive the reflected light information on sample, feeds back to control single Unit；

Receiving mechanism: remain and align with radiation source, receives the transmission light of radiation source, and it is single to feed back to control Unit；

Control unit: control radiation source, guiding mechanism, receiving mechanism work, anti-according to radiation source or receiving mechanism The spectral information of feedback, calculates sample signal to noise ratio by accidental resonance analysis meter, and with drawing sample freshness after tables of data Information.

Present system detects degree of beef freshness by spectrum analysis, it is possible to more rapid, easy, detect beef accurately Freshness.Radiation source is used for launching detecting light beam, also can receive irreflexive light on sample simultaneously.This radiation source rotates Being connected on guiding mechanism, radiation source can rotate around axle, and guiding mechanism can carry out rotating and altitude mixture control simultaneously, this Sample makes radiation source irradiation position can all cover sample.Receiving mechanism is used for receiving light beam transmission light on sample, When radiation source irradiation position changes, receiving mechanism position to be adjusted remains aligns with radiation source.Radiation source, Guiding mechanism, receiving mechanism all feed back information to control unit, and control unit controls they work according to their information.Control The spectral information detected the most also to be analyzed calculating by unit processed, draws snr value, also stores in control unit There is pre-set beef each freshness criteria Value Data table, by drawing sample after comparing with the snr value calculated Freshness.Radiation source uses Halogen light or generating laser.Beef can lossless be detected by this device, it is adaptable to on-the-spot Beef is detected by high-volume.

As a kind of preferred version, described receiving mechanism includes receptor, slide and swingle, and described slide is to shine Penetrating the arcuate structure that light source rotating shaft is the center of circle, slide offers chute, described receptor is arranged in chute, in chute both sides Being provided with gathering sill on wall, be correspondingly arranged on directive wheel, gathering sill is toothed around on receptor both sides, directive wheel is arranged on In gathering sill, directive wheel is gear, and directive wheel is meshed with gathering sill and is connected, and slide is fixed on swingle upper end, and swingle turns Move and be arranged on pedestal.Receptor is used for receiving transmitted ray, and this receptor to keep aliging, at radiation source with radiation source Time mobile, rotate so that receptor moves, owing to this slide is with radiation source rotating shaft as the center of circle by controlling directive wheel Arcuate structure, therefore mobile receiver so that receptor keep align with radiation source.This swingle can drive cunning Seat rotates, when radiation source rotates, by controlling swingle synchronous rotary so that receptor keeps and irradiates light Source keeps alignment.

As a kind of preferred version, in described receptor, it is provided with the driving motor of output shafts, drives the two of motor Individual output shaft is connected with directive wheel respectively, connects the first motor driving swingle to rotate in described swingle lower end, drives electricity Machine and the first motor are connected in control unit, bottom receptor on be provided with roller.Motor is driven to drive directive wheel Rotate so that receptor moves.First motor drives swingle to rotate.Drive motor and the most controlled unit control of the first motor System, control unit is according to radiation source rotation information, and corresponding control slide rotates and receptor moves, and keeps receptor and irradiation Light source aligns.

As a kind of preferred version, described guiding mechanism includes first body of rod, second body of rod, rotary screw and guide post, First body of rod is vertically arranged, and described radiation source is connected on the lower end of first body of rod by rotating shaft, and rotating shaft rotates with driver The second motor be connected, the first body of rod upper end is through on clutch shaft bearing, is provided with the 3rd motor, the 3rd motor on bearing top Output shaft and the first body of rod upper end connect, and described second body of rod and the perpendicular setting of first body of rod, the second lever front end is fixed on On clutch shaft bearing, being disposed with thread bush and fairlead in the second body of rod rear end, described rotary screw and guide post set side by side Putting on pedestal, thread bush and fairlead are nested with respectively on rotary screw and guide post, and connecting in rotary screw lower end has the Four motors, rotary screw upper end connects the second bearing, and guide post upper end fixes with the second bearing, the second motor, the 3rd motor It is connected in control unit with the 4th motor.First body of rod can be rotated by this guiding mechanism, can adjust the simultaneously The height of bipole body, thus regulate the irradiation position of radiation source.Rotating shaft is inserted perpendicularly into and is arranged on the first lever front end, rotating shaft Front end is fixed on radiation source centre position, and the second motor output shaft is paralleled with rotating shaft, the second motor output shaft alignment rotating shaft Rear end connection fixed thereto, the second motor controls radiation source rotational angle.3rd motor output shaft is parallel with second body of rod, 3rd motor output shaft is connected to the second body of rod upper end so that second body of rod rotates along its axis.4th driven by motor screw mandrel rotation Turning, screw mandrel rotation can drive and be enclosed within thread bush thereon and move up and down, so that the second body of rod oscilaltion, fairlead is enclosed within On guide post so that second body of rod remains and do not rocks and be maintained at lifting in same vertical plane.

A kind of degree of beef freshness detection method, comprises the following steps:

Step one: the total volatile basic nitrogen value of the different resting period beef sample of detection in advance, obtains and some groups and photograph Penetrate the degree of beef freshness threshold value that light source position is corresponding；

Step 2: prepare beef sample, is placed on sample on bracket, and radiation source uses the place identical with step one Position is radiated on sample, and radiation source intensity increases according to tangent cutve during the course then according to cotangent curve declines, control Unit collection reflection processed or transmittance spectra data, then adjust radiation source irradiation position, so some the most not at sample collecting With the reflection put or transmittance spectra data；In this step, the anglec of rotation to its radiation source of sample detection obtains in step one In degree of beef freshness threshold operation, the anglec of rotation of radiation source is the most corresponding.

Step 3: each test point spectroscopic data is substituted in accidental resonance model, by accidental resonance model is carried out Single order and second order derivation, and by single order accidental resonance model by quadravalence jade for asking rain Ge Kuta algorithm, calculate each test point noise Compare output valve；

Step 4: freshness threshold corresponding for each test point signal to noise ratio output valve is compared and draws each test point Signal to noise ratio output error value, then carries out classified statistic to each signal to noise ratio output error value, it is judged that whether sample is fresh.

As a kind of preferred version, the volatile base nitrogen TVB-of the different resting period beef sample of detection in advance in step one N value, obtains degree of beef freshness threshold value SNR corresponding with the radiation source anglec of rotation with some groups_thre1、SNR_thre2、…、 SNR_threi, i=1 ... m, m are test point quantity.

As a kind of preferred version, each spectroscopic data gathered is substituted in accidental resonance model by step 3 respectively, its Formula is as follows,

WhereinFor input matrix, including periodic sinusoidal signalSpectroscopy signal Spect (t), and in grasp noise N (t), A is signal amplitude, f be signal frequency Rate, D is outer noise intensity, and ξ (t) is outer noise, and x (t) is Brownian movement Particles Moving lopcus function, and t is movement time；

Accidental resonance model is carried out single order and second order derivation is that (x t) carries out single order and second order derivation for x, and makes V Obtaining its equation is 0, and obtaining formula is,

Set noise intensity D=0,Spect (t)=0, N (t)=0, B=1 tries to achieve periodically The marginal value of signal is

By A_cSubstitute in first derivation function, if X₀(t)=0, sn₀=0；

With quadravalence jade for asking rain Ge Kuta Algorithm for Solving single order 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

${\left(k_1\right)}_n=4\left({\mathrm{ax}}_{n-1}\right(t)-{\mathrm{bx}}_{n-1}^3(t)+{\mathrm{sn}}_{n-1})$

${\left(k_2\right)}_n=4\[a\left(x_{n-1}\right(t)+\frac{{\left(k_1\right)}_{n-1}}{2})-b{\left(x_{n-1}\right(t)+\frac{{\left(k_1\right)}_{n-1}}{2})}^3+{\mathrm{sn}}_{n-1}\]$

${\left(k_3\right)}_n=4\[a\left(x_{n-1}\right(t)+\frac{{\left(k_2\right)}_{n-1}}{2})-b{\left(x_{n-1}\right(t)+\frac{\sqrt{2}-1}{2}{\left(k_1\right)}_{n-1}+\frac{2-\sqrt{2}}{2}{\left(k_2\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}\]$

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

Wherein x_nFor the n order derivative value of x (t), sn_nIt is the n order derivative of S (t) value at t=0, n=0,1 ..., N-1, A, b are the constant set, and are calculated x₁(t),x₂(t),…,x_n+1The value of (t)；

To x₁(t),x₂(t),…,x_n+1T () is integrated, obtain x (t), and obtain x (t) at single order and second order derivation letter The double-deck stochastic system that array becomes produces the position x in accidental resonance moment_mValue and x_mCorresponding resonance moment t1 and with t1 institute Corresponding noise D1, D1 are a value in D；D be in the range of [0,1] with a function of 0.01 stepping it is known that the t1 moment, D1 determines that.

Then formula is passed through

$SNR=\sqrt{2}{\left(\mathrm{\Δ}U\frac{4a^3/27b}{D_1}\right)}^2{e}^{-{\left(\mathrm{\Δ}U\right)}^2/D_1}$

Calculate the signal to noise ratio of each spectroscopic data output, obtain SNR₁,SNR₂,…,SNR_i, wherein △ U=a²/4b.In reality In engineering survey, the data of measurement generally comprise echo signal and interference noise, if echo signal is covered by strong background noise Lid, we cannot accurately detect.With the help of accidental resonance, inside grasp that noise is weakened and echo signal small-signal Then effectively amplified so that echo signal is likely caught in.Sometimes the faintest due to echo signal and background noise Too strong, monolayer accidental resonance can not effectively reduce system noise, is therefore accomplished by by monolayer accidental resonance output signal again Secondary delivering to is analyzed in next layer of stochastic resonance system, so can finally realize the purpose that Target Weak Signal is measured.

As a kind of preferred version, in step 4, output signal-to-noise ratio error is by each test point output signal-to-noise ratio and corresponding inspection The freshness threshold of measuring point calculates, and its formula isThe process of statistics is meter Calculation meets QE_iThe number of the output signal-to-noise ratio error of≤5%, is designated as M₁, calculate and meet QE_i> 5% output signal-to-noise ratio error Number, is designated as M₂If,Then make the judgement that sample is fresh, ifThen make sample stale Judge, sample is detected again if the most otherwise returning step 2 and carries out data process.

As a kind of preferred version, the detection process of degree of beef freshness threshold value is: detect the volatility of a beef every day Alkali nitrogen numerical value, until the total volatile basic nitrogen numerical value of certain day sample exceeds standard for the first time, then carries out step 2 extremely by this day sample The operation of step 3, the signal to noise ratio obtained output is freshness threshold, during detection by first time radiation source position, it After detect each time, radiation source angle is by clockwise increasing by 5 degree.

Therefore, the invention have the advantage that employing spectroscopic way, sample can be carried out Non-Destructive Testing；Apparatus structure letter Single, operate fast and convenient, detection data are accurate.

Accompanying drawing explanation

Accompanying drawing 1 is a kind of structural representation of apparatus of the present invention；

Accompanying drawing 2 is a kind of structural representation of receiving mechanism in apparatus of the present invention；

Accompanying drawing 3 is a kind of cross-sectional view of receiving mechanism slide in the present invention；

Accompanying drawing 4 is the connection block schematic illustration in the present invention between control unit and receiving mechanism, guiding mechanism；

Accompanying drawing 5 is a kind of schematic flow sheet of method in the present invention；

Accompanying drawing 6 is radiation source conversion curve figure in the present invention.

1-pedestal 2-bracket 3-radiation source 4-guiding mechanism 5-receiving mechanism 6-receptor 7-slide 8-rotates Bar 9-chute 10-gathering sill 11-directive wheel 12-control unit 13-drives motor 14-the first motor 15-the second motor 16-the 3rd motor 17-the 4th motor 18-first body of rod 19-second body of rod 20-rotary screw 21-guide post 22-rotating shaft 23-clutch shaft bearing 24-thread bush 25-fairlead 26-the second bearing

Detailed description of the invention

Below by embodiment, and combine accompanying drawing, technical scheme is described in further detail.

Embodiment:

The present embodiment one degree of beef freshness detecting system, as it is shown in figure 1, include pedestal 1, pedestal is provided with for Placing the bracket 2 of sample, bracket is connected on pedestal by support column.It is provided above radiation source 3, on pedestal at bracket Being provided with the guiding mechanism 4 adjusting radiation source position, radiation source is rotatably connected on guiding mechanism 4, sets below bracket It is equipped with receiving mechanism 5, the present internal control unit 12 that arranges, control unit and radiation source, adjusting pole, receiving mechanism phase Even.

As shown in Figures 2 and 3, receiving mechanism 5 includes receptor 6, slide 7 and swingle 8, and slide is with radiation source Rotating shaft is the arcuate structure in the center of circle, slide has and is provided with chute 9, and receptor mobile link is in chute, in chute two side On be provided with gathering sill 10, receptor both sides are correspondingly arranged on directive wheel 11, gathering sill are toothed around, directive wheel install In gathering sill, directive wheel is gear, and directive wheel is meshed with gathering sill and is connected, bottom receptor on be provided with roller, roller Contact with bottom chute.It is provided with the driving motor 13 of output shafts in receptor, drives two output shafts of motor respectively It is connected with directive wheel 11.Slide is fixed on swingle upper end, and swingle rotates and is arranged on pedestal 1, and swingle lower end connects drives The first motor 14 that dynamic swingle rotates, drives motor and the first motor to be connected in control unit 12.

As it is shown in figure 1, guiding mechanism 4 includes first body of rod 18, second body of rod 19, rotary screw 20 and guide post 21, the One body of rod is vertically arranged, and radiation source 3 is connected on the lower end of first body of rod by rotating shaft 22, rotating shaft and driver rotate the Two motors 15 are connected, and the first body of rod upper end is through on clutch shaft bearing 23, are provided with the 3rd motor 16, the 3rd electricity on bearing top Machine output shaft and the first body of rod upper end connect, second body of rod and the perpendicular setting of first body of rod, and the second lever front end is fixed on the On one bearing, it is disposed with thread bush 24 in the second body of rod rear end and fairlead 25, rotary screw and guide post are arranged side by side On pedestal, thread bush and fairlead are nested with respectively on rotary screw and guide post, and connecting in rotary screw lower end has the 4th Motor 17, rotary screw upper end connects the second bearing 26, and guide post upper end fixes with the second bearing, the second motor, the 3rd electricity Machine and the 4th motor are connected in control unit 12.

Guiding mechanism controls radiation source position, and radiation source can rotate under the second motor controls around the shaft, Control radiation source irradiating angle.First body of rod can pivot under the 3rd motor controls, and adjusts radiation source planar 360 degree of rotations, rotary screw can adjust the second body of rod oscilaltion, adjusts the radiation source position at height.Receive structure Middle swingle is controlled to rotate by the first motor, and control unit controls the first motor anglec of rotation and the 3rd motor anglec of rotation one Sample, i.e. makes first body of rod anglec of rotation as the slide anglec of rotation so that receptor can align radiation source all the time.Drive Motor drives receptor to move, and this receptor to keep aliging with radiation source, and receptor is when mobile, upon receipt of irradiation The transmission light of light source, then stop mobile, and now receptor aligns with radiation source.

As it is shown in figure 5, degree of beef freshness detection method comprises the following steps:

Step one: the total volatile basic nitrogen value of the different resting period beef sample of detection in advance, obtains and some groups and photograph Penetrate the degree of beef freshness threshold value that light source position is corresponding.It is specially total volatile basic nitrogen TVB-detecting a beef every day N value, until the total volatile basic nitrogen numerical value of certain day sample exceeds standard for the first time, then this day sample is followed the steps below in advance two to The operation of step 3, the signal to noise ratio output SNR of each test point now obtained_thre1、SNR_thre2、…、SNR_threi, i= 1 ... m, it is freshness threshold, m is test point quantity, during detection by first time radiation source position, the most each Secondary detection, radiation source angle is by increasing by 5 degree clockwise.

Step 2: prepare beef sample, beef sample thickness is 2mm-10mm, uses the sample of 5mm thickness in the present embodiment Product.Being placed on bracket by sample, radiation source uses the position identical with step one to be radiated on sample, such as Fig. 6 institute Showing, radiation source intensity increases according to tangent cutve during the course then according to cotangent curve declines change, control unit collection Reflection or transmittance spectra data, then adjust radiation source irradiation position, so in the reflection of the some variant points of sample collecting Or transmittance spectra data；

Step 3: each test point spectroscopic data is substituted in accidental resonance model, by accidental resonance model is carried out Single order and second order derivation, and by single order accidental resonance model by quadravalence jade for asking rain Ge Kuta algorithm, calculate each test point noise Compare output valve.

Substituting in accidental resonance model respectively by each spectroscopic data gathered, its formula is as follows,

WhereinFor input matrix, including periodic sinusoidal signalSpectroscopy signal Spect (t), and in grasp noise N (t), A is signal amplitude, f be signal frequency Rate, D is outer noise intensity, and ξ (t) is outer noise, and x (t) is Brownian movement Particles Moving lopcus function, and t is movement time.

Accidental resonance model is carried out single order and second order derivation is that (x t) carries out single order and second order derivation for x, and makes V Obtaining its equation is 0, and obtaining formula is,

Set noise intensity D=0,Spect (t)=0, N (t)=0, B=1 tries to achieve periodically The marginal value of signal is

By A_cSubstitute in first derivation function, if X₀(t)=0, sn₀=0；

With quadravalence jade for asking rain Ge Kuta Algorithm for Solving single order 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

${\left(k_1\right)}_n=4\left({\mathrm{ax}}_{n-1}\right(t)-{\mathrm{bx}}_{n-1}^3(t)+{\mathrm{sn}}_{n-1})$

${\left(k_2\right)}_n=4\[a\left(x_{n-1}\right(t)+\frac{{\left(k_1\right)}_{n-1}}{2})-b{\left(x_{n-1}\right(t)+\frac{{\left(k_1\right)}_{n-1}}{2})}^3+{\mathrm{sn}}_{n-1}\]$

${\left(k_3\right)}_n=4\[a\left(x_{n-1}\right(t)+\frac{{\left(k_2\right)}_{n-1}}{2})-b{\left(x_{n-1}\right(t)+\frac{\sqrt{2}-1}{2}{\left(k_1\right)}_{n-1}+\frac{2-\sqrt{2}}{2}{\left(k_2\right)}_{n-1})}^3+{\mathrm{sn}}_{n+1}\]$

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

Wherein x_nFor the n order derivative value of x (t), sn_nIt is the n order derivative of S (t) value at t=0, n=0,1 ..., N-1, A, b are the constant set, and are calculated x₁(t),x₂(t),…,x_n+1The value of (t)；

To x₁(t),x₂(t),…,x_n+1T () is integrated, obtain x (t), and obtain x (t) at single order and second order derivation letter The double-deck stochastic system that array becomes produces the position x in accidental resonance moment_mValue and x_mCorresponding resonance moment t1 and with t1 institute Corresponding noise D1, D1 are a value in D.

Then formula is passed through

$SNR=\sqrt{2}{\left(\mathrm{\Δ}U\frac{4a^3/27b}{D_1}\right)}^2{e}^{-{\left(\mathrm{\Δ}U\right)}^2/D_1}$

Calculate the signal to noise ratio of each spectroscopic data output, obtain SNR₁,SNR₂,…,SNR_i, wherein △ U=a²/4b。

Step 4: freshness threshold corresponding for each test point signal to noise ratio output valve is compared and draws each test point Signal to noise ratio output error value, then carries out classified statistic to each signal to noise ratio output error value, it is judged that whether sample is fresh.

Carry out each test point output signal-to-noise ratio with the freshness threshold of corresponding test point being calculated output signal-to-noise ratio by mistake Difference, its formula isThe process of statistics is that calculating meets QE_iThe output letter of≤5% The number of ratio error of making an uproar, is designated as M₁, calculate and meet QE_i> 5% the number of output signal-to-noise ratio error, be designated as M₂If,Then make the judgement that sample is fresh, ifThen make the stale judgement of sample, if the most otherwise returning Return step 2 sample is detected again and carries out data process.

Specific embodiment described herein is only to present invention spirit explanation for example.Technology neck belonging to the present invention Described specific embodiment can be made various amendment or supplements or use similar mode to replace by the technical staff in territory Generation, but without departing from the spirit of the present invention or surmount scope defined in appended claims.

Although the most more employ the terms such as pedestal, bracket, radiation source, guiding mechanism, receiving mechanism, but not Get rid of the probability using other term.Use these terms to be only used to more easily to describe and explain the basis of the present invention Matter；It is all contrary with spirit of the present invention for being construed as any additional restriction.

Claims (7)

1. a degree of beef freshness detecting system, it is characterised in that: include pedestal (1), pedestal is provided with for placing sample This bracket (2), is provided above radiation source (3) at bracket, and described radiation source is rotatably connected on adjustment radiation source position On the guiding mechanism (4) put, guiding mechanism is arranged on pedestal, is provided with receiving mechanism (5) below bracket, internal setting of being present Putting control unit (12), control unit is connected with radiation source, adjusting pole, receiving mechanism；Described receiving mechanism (5) includes Receptor (6), slide (7) and swingle (8), described slide is the arcuate structure with radiation source rotating shaft as the center of circle, on slide Having and be provided with chute (9), described receptor is arranged in chute, is provided with gathering sill (10) on chute two side, is receiving Being correspondingly arranged on directive wheel (11) on device both sides, gathering sill is toothed around, directive wheel is arranged in gathering sill, and directive wheel is tooth Wheel, directive wheel is meshed with gathering sill and is connected, and slide is fixed on swingle upper end, and swingle rotates and is arranged on pedestal (1)；Institute State guiding mechanism (4) and include first body of rod (18), second body of rod (19), rotary screw (20) and guide post (21), first body of rod Being vertically arranged, described radiation source (3) is connected on the lower end of first body of rod by rotating shaft (22), and rotating shaft rotates with driver Second motor is connected, and the first body of rod upper end is through on clutch shaft bearing (23), is provided with the 3rd motor (16) on bearing top, the Three motor output shafts and the first body of rod upper end connect, described second body of rod and the perpendicular setting of first body of rod, the second lever front end It is fixed on clutch shaft bearing, is disposed with thread bush (24) and fairlead (25), described rotary screw in the second body of rod rear end Being disposed side by side on pedestal with guide post, thread bush and fairlead are nested with respectively on rotary screw and guide post, at rotating wire Bar lower end connects the 4th motor (17), and rotary screw upper end connects the second bearing (26), guide post upper end and the second bearing phase Fixing, the second motor, the 3rd motor and the 4th motor are connected in control unit (12)；

Radiation source: electromagnetic radiation is detected light beam, and the reflected light information on sample can be received, feed back to control unit；

Receiving mechanism: remain and align with radiation source, receives the transmission light of radiation source, and feeds back to control unit；

Control unit: control radiation source, guiding mechanism, receiving mechanism work, feed back according to radiation source or receiving mechanism Spectral information, calculates sample signal to noise ratio by accidental resonance analysis meter, and with drawing sample freshness information after tables of data.

A kind of degree of beef freshness detecting system the most according to claim 1, is provided with in it is characterized in that described receptor (6) The driving motor (13) of output shafts, drives two output shafts of motor to be connected with directive wheel (11) respectively, in described rotation Bar lower end connects the first motor (14) driving swingle to rotate, and drives motor and the first motor to be connected to control unit (12) on, bottom receptor on be provided with roller.

3. a degree of beef freshness detection method, uses the system in any one of claim 1-2, it is characterized in that: include following Step:

Step one: the volatile base values of nitrogen might of the different resting period beef sample of detection in advance, obtains some groups and radiation source institute The degree of beef freshness threshold value corresponding in position；

Step 2: prepare beef sample, is placed on sample on bracket, and radiation source uses the position identical with step one Being radiated on sample, radiation source intensity increases according to tangent cutve during the course then according to cotangent curve declines change, control Unit collection reflection processed or transmittance spectra data, then adjust radiation source irradiation position, so some the most not at sample collecting With the reflection put or transmittance spectra data；

Step 3: each test point spectroscopic data is substituted in accidental resonance model, by accidental resonance model is carried out single order With second order derivation, and by single order accidental resonance model by quadravalence jade for asking rain Ge Kuta algorithm, calculate each test point signal to noise ratio defeated Go out value；

Step 4: freshness threshold corresponding for each test point signal to noise ratio output valve is compared and draws each test point noise Ratio output error value, then carries out classified statistic to each signal to noise ratio output error value, it is judged that whether sample is fresh.

A kind of degree of beef freshness detection method the most according to claim 3, is characterized in that detecting in advance in step one difference The volatile base nitrogen TVB-N value of resting period beef sample, obtains the beef corresponding with the radiation source anglec of rotation with some groups Freshness threshold SNR_thre1、SNR_thre2、…、SNR_threi, i=1 ... m, m are test point quantity.

A kind of degree of beef freshness detection method the most according to claim 3, is characterized in that each light that will gather in step 3 Modal data substitutes in accidental resonance model respectively, and its formula is as follows,

WhereinFor input matrix, including periodic sinusoidal signalSpectroscopy signal Spect (t), and in grasp noise N (t), A is signal amplitude, f be signal frequency Rate, D is outer noise intensity, and ξ (t) is outer noise, and x (t) is Brownian movement Particles Moving lopcus function, and t is movement time；

Accidental resonance model is carried out single order and second order derivation is that (x t) carries out single order and second order derivation for x, and makes it V Equation is 0, obtains formula and is,

Set noise intensity D=0,Spect (t)=0, N (t)=0, B=1 tries to achieve cyclical signal Marginal value be

By A_cSubstitute in first derivation function, if X₀(t)=0, sn₀=0；

With quadravalence jade for asking rain Ge Kuta Algorithm for Solving single order accidental resonance model, obtain:

And calculate

Wherein x_nFor the n order derivative value of x (t), sn_nIt is the n order derivative of S (t) value at t=0, n=0,1 ..., N-1, a, b are The constant set, is calculated x₁(t),x₂(t),…,x_n+1The value of (t)；

To x₁(t),x₂(t),…,x_n+1T () is integrated, obtain x (t), and obtain x (t) in single order and second order derivation group of functions The double-deck stochastic system become produces the position x in accidental resonance moment_mValue and x_mCorresponding resonance moment t1 and with t1 corresponding to Noise D1, D1 be a value in D；

Then formula is passed through

Calculate the signal to noise ratio of each spectroscopic data output, obtain SNR₁,SNR₂,…,SNR_i, wherein

△ U=a²/4b。

A kind of degree of beef freshness detection method the most according to claim 4, is characterized in that in step 4, output signal-to-noise ratio is by mistake Difference is for calculate each test point output signal-to-noise ratio with the freshness threshold of corresponding test point, and its formula isThe process of statistics is that calculating meets QE_iThe number of the output signal-to-noise ratio error of≤5%, It is designated as M₁, calculate and meet QE_i> 5% the number of output signal-to-noise ratio error, be designated as M₂If,Then make sample fresh Judgement, ifThen making the stale judgement of sample, if the most otherwise returning step 2, sample being detected also again Carry out data process.

7., according to a kind of degree of beef freshness detection method described in claim 3 or 4, it is characterized in that the inspection of degree of beef freshness threshold value Survey process is: detect the total volatile basic nitrogen numerical value of a beef every day, until the total volatile basic nitrogen numerical value of certain day sample Once exceeding standard, then this day sample carry out step 2 to the operation of step 3, the signal to noise ratio obtained output is freshness threshold, During detection by first time radiation source position, detecting the most each time, radiation source angle is by increasing by 5 degree clockwise.