Intelligent poultry egg detection platform and detection method

Abstract

The poultry egg intelligent detection platform mainly comprises a shell, a conveying device is installed on the shell, and a knocking detection mechanism is arranged above the conveying device; the conveying device comprises a double-row-chain conveying mechanism which is driven by a speed adjusting motor to rotate. Transmission rods are rotatably installed between transmission chains of the double-row-chain conveying mechanism at intervals in the conveying direction, and egg holders are installed in the middles of the transmission rods. The multiple sets of knocking detection mechanisms are operated in a time-sharing mode, and the interval time of the adjacent knocking actions is larger than the sound wave attenuation time. According to the intelligent poultry egg detection platform and detection method provided by the invention, the detection precision of existing poultry eggs can be improved.

Description

Technical Field

[0001] The present invention relates to the field of poultry egg crack detection, and particularly to an intelligent detection platform and detection method for poultry eggs. Background Art

[0002] Acoustic detection technology is based on the propagation characteristics of sound in different media. When a poultry egg is tapped, a sound signal with different characteristics will be generated due to the different external structures and physical properties of a complete poultry egg and a cracked poultry egg. The external structure of a complete poultry egg is uniform, and the sound signal is relatively regular and stable; while for a cracked poultry egg, its crack will cause phenomena such as scattering and reflection during the sound propagation process, causing changes in waveform characteristics such as the frequency and amplitude of the sound signal.

[0003] Through the precise analysis of the sound signal, fine cracks and internal cracks can be accurately identified, overcoming the deficiencies of manual detection and some traditional detection methods, and improving the accuracy and reliability of detection.

[0004] Existing poultry egg crack detection methods are mainly divided into manual detection, optical detection, and acoustic detection. Manual visual inspection or sampling inspection has problems such as low screening efficiency and high missed detection / misjudgment rates. Long-term operation is likely to cause visual fatigue and further reduce the accuracy, making it difficult to meet the high standards of quality control for large-scale production lines. Optical detection is affected by stains on the eggshell surface, lighting conditions, and texture interference, and has insufficient recognition accuracy for microcracks (especially superficial cracks), and is prone to misjudgment. Acoustic detection requires precise control of the force and position during percussion excitation. If the percussion point deviates from the crack area, the signal characteristics are similar to those of a normal egg, resulting in detection failure. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an intelligent detection platform and detection method for poultry eggs, which collect sound signals by tapping the poultry eggs with a tapping head group, and use a poultry egg crack recognition algorithm to judge whether the poultry eggs have cracks, etc., solving the problem that it is inconvenient to detect cracked eggs during poultry egg production at present, and improving the technical problem of the existing poultry egg detection accuracy.

[0006] To solve the above technical problem, the technical solution adopted by the present invention is:

[0007] A novel poultry egg crack detection device, including a housing, on which a conveying device is installed, and a percussion detection mechanism is arranged above the conveying device;

[0008] The conveying device includes a double-row chain conveying mechanism, and the double-row chain conveying mechanism is driven to rotate by a speed-regulating motor; between the transmission chains of the double-row chain conveying mechanism, transmission rods are installed at intervals along the conveying direction and are rotatably installed, and an egg holder is installed in the middle of the transmission rod;

[0009] The knocking detection mechanisms are multiple groups, and the multiple groups of knocking detection mechanisms are operated in time-sharing, and the interval time between adjacent knocking actions is greater than the sound wave attenuation time.

[0010] Transmission gears are installed at both ends of the egg holder, and the transmission gears are meshed with the racks below.

[0011] The shell comprises a bottom frame, a protective shell is arranged in the middle of the bottom frame, and a material inlet and outlet baffle is installed at the output end of the bottom frame.

[0012] The egg holder is wheel-shaped, thin in the middle and thick at both ends, with a smooth transition, and the spacing between adjacent egg holders is smaller than the diameter of the egg.

[0013] The egg holder is made of food-grade silicone.

[0014] The knock detection mechanism is installed on the inner side of the bottom frame through a fixed bracket and is symmetrically distributed above the egg holder.

[0015] The knocking detection mechanism comprises a base, a knocking head is hinged on the base, and the knocking head is adsorbed or detached from the electromagnet on the base.

[0016] The present invention provides an intelligent egg detection platform and detection method, which have the following technical effects:

[0017] 1) By setting a double-row chain transmission mechanism, a plurality of rotatable transmission rods are installed along the length direction of the double-row chain transmission mechanism, and egg holders are arranged on the transmission rods. Adjacent egg holders can support the eggs and drive them forward at the same time; at the same time, since a transmission gear is arranged on the transmission rod, the transmission gear is meshed with a rack fixedly installed below, the transmission gear not only takes into account the load-bearing balance and reduces vibration, but also enables the eggs to roll forward, which is convenient for knocking detection from different positions to ensure comprehensiveness (in this application, knocking is achieved at the head and tail ends, in four directions, and a total of eight points, which effectively improves the comprehensiveness and accuracy of the detection).

[0018] 2) This detection platform uses a high-precision knocking head group. Since this detection platform needs to knock on 8 parts at the same time, it is necessary to avoid mutual interference as much as possible to cause errors (the knocking device is operated in time-sharing mode to ensure that the interval between each knocking action is greater than the sound wave attenuation time). This makes the device easy to detect cracked eggs and is convenient for users to use.

[0019] 3) Adaptable to eggs of different sizes: The speed of the conveyor belt remains constant, while the size of the eggs affects their rotational speed on the conveyor belt. Taking duck eggs as an example, the smaller ones have a diameter of about 40 mm, while the larger ones can reach more than 60 mm in diameter. Therefore, to achieve a uniform distribution of the tapping points, it is necessary to classify the egg weights, calculate their diameters, calculate the tapping heads to be activated in combination with the running speed of the conveyor belt, and activate them in sequence to achieve the purpose of uniformly tapping the eggshell surface. Thus, it can adapt to eggs of different sizes. Brief Description of the Drawings

[0020] The present invention will be further described below in conjunction with the drawings and embodiments:

[0021] Figure 1 Schematic diagram of the installation structure of the present invention (the protective shell is opened).

[0022] Figure 2 Schematic diagram of the installation structure of the present invention (the protective shell is closed).

[0023] Figure 3 Schematic layout diagram of the tapping detection mechanism and the conveying device of the present invention (front view).

[0024] Figure 4 Schematic layout diagram of the tapping detection mechanism and the conveying device of the present invention (top view).

[0025] Figure 5 Schematic layout diagram of the tapping detection mechanism and the conveying device of the present invention (left view).

[0026] Figure 6 Schematic diagram of the structure of the tapping detection mechanism and the conveying device of the present invention.

[0027] In the figure: housing 1, conveying device 2, tapping detection mechanism 3, egg 4, feeding and discharging baffle 1.1, bottom frame 1.2, protective shell 1.3, double-row chain conveying mechanism 2.1, speed regulating motor 2.2, support plate 2.3, transmission rod 2.4, egg holder 2.5, transmission gear 2.6, rack 2.7. Detailed Embodiments

[0028] As Figures 1-4 shown, an intelligent egg detection platform includes a housing 1, a conveying device 2 is installed on the housing 1, and a tapping detection mechanism 3 is arranged on the conveying device 2.

[0029] The housing 1 includes a bottom frame 1.2, a protective shell 1.3 is provided in the middle of the bottom frame 1.2, and a feeding and discharging baffle 1.1 is installed at the output end of the bottom frame 1.2. The advantage of setting the feeding and discharging baffle 1.1 is to prevent the eggs from rolling and being damaged, and improve the stability of egg input during sorting.

[0030] The conveying device 2 includes a double-row chain conveying mechanism 2.1. The sprockets of the double-row chain conveying mechanism 2.1 are driven by a speed-regulating motor 2.2, and the speed-regulating motor 2.2 is installed on a support plate 2.3. Transmission rods 2.4 are installed at intervals along the conveying direction between the transmission chains of the double-row chain conveying mechanism 2.1. The transmission rods 2.4 are coaxial with the pins of the two transmission chains and are rotatable. An egg carrier 2.5 is arranged in the middle of the transmission rod 2.4. The poultry eggs 4 are located between two adjacent egg carriers 2.5 and are supported by the two egg carriers 2.5. Transmission gears 2.6 are fixedly installed on the transmission rods 2.4 outside the egg carriers 2.5. The transmission gears 2.6 can be arranged symmetrically left and right outside the egg carriers 2.5 or on one side. The lower ends of the transmission gears 2.6 are engaged with racks 2.7. During the forward conveying of the transmission chains, the transmission gears 2.6 roll forward along the racks 2.7, so that the transmission rods 2.4 and the egg carriers 2.5 all rotate accordingly, thereby driving the poultry eggs 4 to rotate.

[0031] The combination of the transmission gear 2.6 and the rack 2.7 can not only provide a certain support, but also make the egg carrier 2.5 rotate while moving forward, realizing the rolling forward of the poultry eggs 4, which is convenient for detection.

[0032] When the detection platform starts to run and the speed-regulating motor 2.2 is started, the output shaft of the speed-regulating motor 2.2 is connected to the main shaft to drive the sprockets. The sprockets and the transmission chains cooperate to drive the transmission rods 2.4 and the egg carriers 2.5 to move forward. At the same time, the transmission gears 2.6 at both ends of the transmission rod 2.4 will roll forward on the racks 2.7. During the rotation of the egg carrier 2.5, the poultry eggs 4 will realize rolling forward.

[0033] The egg carrier 2.5 is wheel-shaped, thin in the middle and thick at both ends, with a smooth transition. The egg carrier 2.5 is made of food-grade silica gel. Silica gel has a high coefficient of friction and elasticity. The distance between adjacent egg carriers 2.5 is appropriate, which is convenient for supporting the poultry eggs 4.

[0034] There are 8 groups of knocking detection mechanisms 3. The 8 groups of knocking detection mechanisms 3 are installed on the inner side of the outer frame through fixed brackets. The 8 groups of knocking detection mechanisms 3 are arranged in parallel above the egg carriers 2.5 and are mirror-symmetrically distributed in two groups, front and back.

[0035] The 8 groups of knocking detection mechanisms 3 adopt stepped trigger delay. Based on the conveyor belt linear velocity v (unit: m / s) and the distance d between adjacent poultry eggs (unit: m), the time interval ΔT = d / (2v) is calculated. For example: when v = 0.1 m / s and d = 0.15 m, ΔT = 0.75 s, ensuring that the previous group of knocking signals attenuate to the background noise level (≤40 dB) before triggering the next group.

[0036] Each set of knocking detection mechanisms 3 has the same knocking head structure as that in the patented "Control Board for a Knocking Head for Detecting Cracks in Poultry Eggs" with the patent number "202321746094.8":

[0037] 1) Design objectives:

[0038] The knocking device needs to have sufficient knocking force; it should be quiet enough during excitation to avoid affecting the acquisition of knocking signals; it can control excitation and reset to ensure the smoothness of the knocking action.

[0039] 2) Structural design

[0040] To meet the design objectives, this paper proposes an electromagnetic knocking device, whose structure consists of the following three parts:

[0042] A. Execution device, the base is hinged to the knocking rod to perform the main movement;

[0043] B. Reset device, the tail end of the base is connected to the knocking rod through a reset rotating shaft composed of a pin shaft sleeve, a bearing and a torsion spring;

[0045] C. Electromagnetic excitation device, a permanent magnet is installed in the middle of the knocking head, corresponding to the position of the electromagnet in the middle of the base, with a sound-absorbing cotton gasket sandwiched between them;

[0046] 3) Structural composition

[0047] The main body of this knocking device includes a base, an electromagnet, a sound-absorbing cotton gasket, a permanent magnet, a silica gel sleeve, an iron core, a rotating body, a pin shaft, a sleeve, a bearing, a torsion spring and a pin shaft nut.

[0048] 4) Structural features

[0049] To generate a knocking force with a controllable magnitude and excitation-reset time, an electromagnet is used as the source of the knocking force. By adjusting the current magnitude and the number of turns of the coil, the knocking force magnitude that meets the theoretical requirements can be achieved, approximately 8.7 N

[43] ;

[0051] By controlling the passage time, the excitation-reset time of the electromagnet is controlled; a sound-absorbing cotton gasket is installed at the electromagnet suction place, and a bearing is installed at the hinge to reduce the vibration and noise generated by friction.

[0053] The array composed of this knocking device is uniformly scheduled and excited by the Mega 2560Pro chip.

[0054] When the poultry egg 4 reaches the specified position, the electromagnet of the knocking head (made of silica gel) is instantly powered on, resulting in the generation of a magnetic field. At this time, the knocking head (iron core) moves rapidly downward due to the electromagnetic force, realizing the knocking on the eggshell of the poultry egg 4. After the knocking is completed, the electromagnet is powered off and the magnetic field disappears. Since a torsion spring is installed on the knocking head part, due to the reset of the torsion spring, the knocking head lifts up, preparing for the next knocking.

[0055] After each tapping is completed, the poultry egg advances to the next tapping position and rotates simultaneously during the advancement. It rotates 1 / 4 turn for each advancement to the next tapping position, so as to realize multi-angle tapping of the poultry egg 4 and comprehensively inspect for cracks in the poultry egg 4.

[0056] In addition, this device is provided with sensors. The sensors are sound signal sensors, and the model is the audio module sensor of Hengkai data acquisition card. There are a total of 8 sensors, which are arranged at a position 10 mm away from the poultry egg. The tapping head group taps the poultry egg to generate sound, and the sound signal will be collected by the sound signal sensor and then converted into a voltage signal through the NI-USB6009 data acquisition card. The signal waveform can be presented in real time on the LabVIEW software, and the window function can be used to intercept the specific tapping waveform required. LabVIEW supports filtering, time-frequency domain analysis, Fourier transform and correlation analysis of the collected sound signal, and at the same time supports waveform playback of the signal of a certain poultry egg collected. Finally, the waveform is compared with the waveform of the poultry egg that has undergone feature extraction and training through the machine learning algorithm before, and finally the quality of the poultry egg is judged and output.

[0057] The sound card installed in this device, with the model of NI-USB6009, is arranged beside the single-chip microcomputer. As a hardware device for processing sound signals, the sound card is not only responsible for processing the received sound signals, but also for amplifying them and performing analog-to-digital conversion (AD conversion). The program compiled by keil needs to be imported during the detection process. The computer is connected to the sound card through the USB interface to realize the reception of audio signals. In addition, the computer can work in coordination with multiple sound cards at the same time, so as to support the simultaneous acquisition of multi-channel audio signals.

[0058] A new method for detecting cracks in poultry eggs includes the following steps:

[0059] Step 1: Classification and parameter calibration of poultry eggs

[0060] 1.1. Modeling of weight-diameter relationship

[0061] An empirical formula for the weight m (unit: g) and diameter D (unit: mm) of poultry eggs is established through experimental measurement:

[0062] D = k·m 1 / 3 +b;

[0063] Among them, k and b are regression coefficients (for example: for duck eggs, k = 8.2, b = 22.3, R 2 >0.95);

[0064] 1.2. Calculation of rotation speed

[0065] The relationship between the angular velocity ω (rad / s) of the self-rotation of the poultry egg on the conveyor belt, the linear velocity v (m / s) of the conveyor belt, and the diameter D is as follows:

[0066]

[0067] Derivation basis: The condition of non-slip rolling of the egg body (circumference C = πD, the time for one rotation t = C / v, so ω = 2π / t = 2v / D).

[0068] Step 2: Synchronous control of transportation and self-rotation

[0069] 2.1 Calculation of knocking frequency

[0070] Suppose 4 knocking points are arranged near the head and tail tips of the eggshell respectively. Then the time interval between adjacent knocking points is:

[0071]

[0072] Derivation: The circumference of the equator line is πD, the arc length between adjacent points Δs = πD / 4, and the time for the conveyor belt to move this arc length is Δt = Δs / v = πD / (4v).

[0073] 2.2 Sequencing plan for exciting the knocking heads

[0074] According to the grading results of the poultry egg diameter (for example, D 1 = 40mm, D 2 = 60mm), dynamically adjust the knocking frequency:

[0075] Small eggs (D 1 = 40mm):

[0076]

[0077] Large eggs (D 1 = 60mm):

[0078]

[0079] The controller triggers the corresponding knocking heads in sequence at a Δt period to ensure that the angular interval between knocking points is 90° (360° / 4).

[0080] The two tip parts of the egg are each knocked 4 times, for a total of 8 times.

[0081] Step 3: Dynamic knocking and signal acquisition

[0082] 3.1 Adaptive adjustment of knocking force

[0083] The knocking force F (unit: N) is dynamically adjusted according to the eggshell thickness h (unit: mm), and the relational expression is:

[0084]

[0085] Where: F 0 is the reference tapping force, and D std is the designed standard diameter;

[0086] Example: When D = 60 mm, F = 0.5×(60 / 50) -2 = 0.347 N. This calculation shows that when the eggshell diameter increases from the standard diameter of 50 mm to 60 mm, the tapping force needs to be correspondingly reduced to avoid excessive impact force causing the eggshell to break.

[0087] 3.2. Synchronous acquisition of acoustic signals

[0088] After tapping, delay t d = 1 ms to start signal acquisition (to avoid mechanical vibration noise);

[0089] Sampling frequency f s = 48 kHz, resolution 16 bit, duration T = 50 ms, covering the main frequency band of the signal (1 - 10 kHz).

[0090] Step Four: Signal processing and crack discrimination

[0091] Feature extraction

[0092] Time-domain features: root mean square value (RMS), peak value (V pp ), impulse factor (I = V pp / RMS);

[0093] Frequency-domain features: Frequency band energy ratio (E 3-5kHz / E total ).

[0094] Classification model decision

[0095] Use a pre-trained support vector machine (SVM) classifier, input the feature vector x = [f c , E 3-5kHz , I] T

[0096] , and the discriminant function is:

[0097]

[0098] Where: K(·) is the radial basis kernel function, α i is the support vector weight, and b is the bias term.

[0099] Step Five: Result output and sorting control

[0100] Real-time determination

[0101] If y = +1, it is determined as a cracked egg; otherwise, it is a good egg. When the confidence level P(y|x) > 0.95, the sorting mechanism is triggered.

[0102] Sorting delay compensation

[0103] According to the conveyor belt speed v and the position distance L of the sorting mechanism, calculate the trigger time advance:

[0104]

[0105] In the formula: Tt trigger represents the trigger time advance, and t processing = 50ms is the time consumption for algorithm processing.

Claims

1. An intelligent egg detection platform, characterized in that: It comprises a housing (1), a conveying device (2) is mounted on the housing (1), and a knock detection mechanism (3) is arranged above the conveying device (2); The conveying device (2) comprises a double-row chain conveying mechanism (2.1), which is driven to rotate by a speed regulating motor (2.2); a transmission rod (2.4) is rotatably installed between the transmission chains of the double-row chain conveying mechanism (2.1) at intervals along the conveying direction, and an egg holder (2.5) is installed in the middle of the transmission rod (2.4); The knocking detection mechanisms (3) are multiple groups, and the multiple groups of knocking detection mechanisms (3) are operated at time intervals, and the interval time between adjacent knocking actions is greater than the sound wave attenuation time.

2. The intelligent egg detection platform according to claim 1, characterized in that: Transmission gears (2.6) are installed at both ends of the egg holder (2.5), and the transmission gears (2.6) are meshed with the racks (2.7) below.

3. The intelligent egg detection platform according to claim 1, characterized in that: The housing (1) comprises a bottom frame (1.2), a protective shell (1.3) is provided in the middle of the bottom frame (1.2), and a material inlet and outlet baffle (1.1) is installed at the output end of the bottom frame (1.2).

4. The intelligent egg detection platform according to claim 3, characterized in that: The egg holder (2.5) is wheel-shaped, thin in the middle and thick at both ends, with a smooth transition, and the spacing between adjacent egg holders (2.5) is smaller than the diameter of the egg (4).

5. The intelligent egg detection platform according to claim 4, characterized in that: The egg holder (2.5) is made of food-grade silica gel.

6. The intelligent egg detection platform according to claim 5, characterized in that: The knock detection mechanism (3) is installed on the inner side of the bottom frame (1.2) via a fixed bracket and is symmetrically distributed above the egg holder (2.5).

7. The intelligent egg detection platform according to claim 1, characterized in that: The knocking detection mechanism (3) comprises a base, on which a knocking head is hinged, and the knocking head is attracted to or detached from an electromagnet on the base.

8. The intelligent egg detection platform according to claim 7, characterized in that: The end of the knocking head is made of silicone material.

9. A method for detecting poultry eggs according to a poultry egg intelligent detection platform according to any one of claims 1 to 8, comprising the following steps: Step 1: Egg grading and parameter calibration 1.

1. Modeling the weight-diameter relationship The empirical formula of egg weight m (unit: g) and diameter D (unit: mm) was established through experimental measurement: D=k·m 1 / 3 +b; Where: k and b are regression coefficients; 1.

2. Calculation of rotation speed The relationship between the rotational angular velocity ω (rad / s) of the egg on the conveyor belt, the linear velocity v (m / s) of the conveyor belt, and the diameter D of the egg is: Step 2: Synchronous control of transportation and rotation 2.

1. Calculation of tapping frequency Assuming that 4 knocking points are arranged near the tip of the eggshell head and tail, the time interval between adjacent knocking points is: 2.

2. Head tapping trigger timing planning Dynamically adjust the knocking frequency according to the egg diameter classification results: Small Eggs(D1): Large Egg (D2): Where: N represents the number of egg collection points; Step 3: Dynamic tapping and signal collection 3.

1. Adaptive adjustment of striking force The striking force F (unit: N) is dynamically adjusted according to the eggshell thickness h (unit: mm), and the relationship is: Where: F0 is the reference striking force, D std It is the standard diameter of the design; 3.

2. Synchronous Acquisition of Acoustic Signals Delay after tapping d =1ms, start signal acquisition; Step 4: Signal processing and crack identification The discriminant function is: Where: K(·) is the radial basis kernel function, α i is the support vector weight, b is the bias term, x i represents the i-th sample vector in the training set, and x represents the new input sample vector; Step 5: Result output and sorting control Real-time judgment If y=+1, it is judged as a cracked egg, otherwise it is a good egg. The sorting mechanism is triggered when the confidence level P(y|x)>0.95; Sorting delay compensation According to the conveyor belt speed v and the sorting mechanism position distance L, calculate the trigger time advance: Where: Tt trigger is the trigger time advance, t processing The algorithm processing is time-consuming.

10. A method for detecting poultry eggs according to an intelligent poultry egg detection platform according to any one of claims 1 to 8, characterized in that: The controller triggers the corresponding knocking heads in sequence according to the Δt period. After each knocking is completed, the egg moves forward to the next knocking point and rotates at the same time during the moving process, rotating 1 / 4 circle for each knocking position, so that the angle between the knocking points of the egg is 90°.

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