Multi-specification walnut internal defect intelligent detection device

Abstract

The invention discloses an intelligent detection device for internal defects of multi-specification walnuts. The intelligent detection device comprises a hopper-shaped stock bin, a walnut size grading mechanism, a baffle type conveying belt, a directional sorting mechanism, a piezoelectric sensing platform, a signal collecting and processing system and an upper computer. A walnut size grading mechanism is arranged below an outlet of the hopper-shaped stock bin, a baffle type conveying belt is arranged at an outlet of the walnut size grading mechanism, a directional sorting mechanism is arranged below an outlet of the baffle type conveying belt, and a piezoelectric sensing platform is arranged below an outlet of the directional sorting mechanism. The piezoelectric sensing platforms are connected with the signal collecting and processing system, and the signal collecting and processing system is further connected with the upper computer. The piezoelectric sensing platform comprises a film type piezoelectric sensor, a damping base platform, an anti-overflow baffle and a push rod module. The film type piezoelectric sensor is adopted to collect vibration response signals of free falling of the walnuts at the same height, empty-shell and full walnuts are distinguished through the distinguishing model, and nondestructive testing of the internal quality of the walnuts is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of walnut sorting, and particularly relates to an intelligent detection device for internal defects of walnuts of multiple specifications. Background Art

[0002] The current mainstream methods for walnut size sorting include manual sorting, mechanical sorting, intelligent sorting, and air separation. Manual sorting is inefficient and costly, and while its accuracy is high, it is susceptible to environmental and human factors. Mechanical sorting primarily includes screen sorting and drum sorting. Screen sorting uses a flat or curved screen, coupled with a vibrating device to help walnuts of different sizes pass through different sieve apertures, thereby achieving size separation. This technology is low-cost and easy to operate, and can be adapted to different production requirements by simply replacing sieve plates with different apertures and shapes. However, if the walnuts are mixed with impurities or are not dry enough, the sieve apertures can easily become clogged, affecting sorting efficiency. Furthermore, the screen area is relatively limited, with a limited number of apertures, limiting the number of walnuts that can be sorted per unit time and resulting in moderate sorting efficiency. Drum sorting uses a drum with varying apertures to sort walnuts by size. This technique can be thought of as a cylindrical screen structure rotating around a fixed axis. Walnuts rotate within the drum, and when their diameter is smaller than the aperture, they fall through, separating them by size. This technology offers a relatively high degree of automation, requires minimal human intervention, and is highly efficient. By adjusting the speed and aperture, it can be adapted to different production requirements. However, this technology is costly, the drum structure is more complex, and it occupies a larger area, resulting in relatively high maintenance costs. Intelligent sorting, including image recognition and spectral recognition technologies, offers high precision and automation, but also carries high costs and requires specialized training. Air separation, which primarily uses fans to separate walnuts of different sizes, is easy to operate and inexpensive, but offers lower precision.

[0003] Walnuts with shrunken interiors, resulting in hollow shells, directly affect their quality and sales, so they need to be removed as much as possible. Existing walnut hollow shell detection technologies primarily utilize non-destructive testing methods, such as image processing, X-ray imaging, and hyperspectral imaging. However, X-ray technology is costly and carries radiation risks, while machine vision technology is significantly affected by environmental factors. Spectroscopic technology and gravity sorting are suitable for rapid detection and preliminary sorting, respectively, but their accuracy is limited.

[0004] Therefore, it is necessary to design a new intelligent detection device for internal defects of walnuts of multiple specifications. Summary of the Invention

[0005] The object of the present invention is to provide an intelligent detection device for internal defects of walnuts with multiple specifications, so as to solve the problems in the background technology that the current walnut size sorting has high cost and poor accuracy; and in the existing walnut shell detection technologies, the X-ray technology has high cost and radiation risk, while the machine vision technology is greatly affected by the environment, and the spectral technology and the specific gravity sorting technology are respectively applicable to rapid detection and preliminary sorting, but the accuracy is limited.

[0006] To achieve the above object, the present invention provides an intelligent detection device for internal defects of walnuts with multiple specifications, which includes a hopper-shaped bin, a walnut size grading mechanism, a baffle-type conveyor belt, an orientation sorting mechanism, a piezoelectric sensing platform, a signal acquisition and processing system, and a host computer;

[0007] Below the outlet of the hopper-shaped bin, there is a walnut size grading mechanism. Different outlets of the walnut size grading mechanism are respectively provided with different baffle-type conveyor belts. Below the outlets of the baffle-type conveyor belts, there are orientation sorting mechanisms. Below the outlets of the orientation sorting mechanisms, there are piezoelectric sensing platforms. The piezoelectric sensing platforms are all connected to the signal acquisition and processing system, and the signal acquisition and processing system is also connected to the host computer;

[0008] The piezoelectric sensing platform includes a thin-film piezoelectric sensor, a shock-absorbing base platform, an anti-overflow baffle, and a push rod module; the shock-absorbing base platform includes a horizontally arranged square bottom plate; the thin-film piezoelectric sensor is adhesively arranged on the upper surface of the square bottom plate; the front and rear sides of the square bottom plate are respectively fixedly welded to the bottom edges of two anti-overflow baffles. The anti-overflow baffles are rectangular and vertically arranged. The square bottom plate and the anti-overflow baffles on the front and rear sides form a U-shaped orientation channel; on both sides of the U-shaped orientation channel, there are push rod modules. The push rod module includes a push plate, an electric push rod, and a push rod bracket. The base of the electric push rod is fixedly connected to the bottom of the square bottom plate through the push rod bracket, and the end of the telescopic end of the electric push rod is fixedly connected to the push plate; the push plates on both sides and the square bottom plate and the anti-overflow baffle group jointly enclose a box-shaped structure with an open upper part; there are gaps between the push plate and the square bottom plate and the anti-overflow baffle group, and the width of the gap is smaller than the diameter of the walnut, so that the walnut will not leak out through the gap.

[0009] In a specific embodiment, the hopper-shaped bin includes a bin main body and a bin support. The bin main body is arranged on the bin support. The lower part of the bin main body is funnel-shaped. There is a bin discharge port at the bottom of the bin main body. The bin discharge port includes a discharge plate with an adjustable inclination angle.

[0010] In a specific embodiment, the walnut size grading mechanism includes a power roller conveyor, side baffles, grading bars, a dial rod, and a dial rod bracket;

[0011] The inlet end of the power roller conveyor is arranged below the hopper-shaped bin;

[0012] The power roller conveyor is equipped with side baffles on both sides of the roller to prevent walnuts from leaking out from the sides;

[0013] The grading baffle is horizontally arranged above the power roller conveyor. The grading baffle cooperates with the roller of the power roller conveyor to grade the walnuts. At least two grading baffles are arranged above the power roller conveyor, and the spacing height between the grading baffle near the entrance end of the power roller conveyor and the roller directly below it decreases in sequence; a roller is arranged directly below the grading baffle.

[0014] The side baffle is provided with a grading outlet, which is provided at the end of the gap between the roller directly below the grading baffle and the adjacent roller on the side of the roller close to the inlet end of the power roller conveyor;

[0015] A shift lever is provided on one side of the grading bar near the inlet end of the power roller conveyor. The shift lever matches the grading outlet and is used to shift the walnuts below the shift lever out of the grading outlet.

[0016] The shifting rod is mounted on the power roller conveyor through a shifting rod bracket. A shifting rod motor is provided on the shifting rod bracket. The shifting rod is connected to the shifting rod motor. The shifting rod motor is used to rotate the shifting rod.

[0017] In a specific embodiment, the shift lever is a Y-shaped shift lever; the Y-shaped shift lever is an integrated shift lever composed of three spoon-shaped single rods with an interval angle of 120°; the speed of the shift lever motor is adjusted according to the transportation speed of walnuts on the powered roller conveyor, thereby controlling the rotation frequency of the Y-shaped shift lever; when the Y-shaped shift lever does not rotate, two of the spoon-shaped single rods respectively stay on both sides of the powered roller conveyor, so that the walnuts will not leak from the grading outlet; when the Y-shaped shift lever rotates, it rotates 120° each time.

[0018] In a specific embodiment, independent discharging channels are provided below the grading outlet and the outlet end of the powered roller conveyor, and walnuts of different grades are respectively introduced into different baffle-type conveyor belts; the discharging channel is a sloped curved slide, the upper end of the discharging channel is connected to the grading outlet or the outlet end of the powered roller conveyor, and a baffle-type conveyor belt is provided below the lower end of the discharging channel.

[0019] In a specific embodiment, the directional sorting mechanism includes a planar conveyor belt and a narrowing structure; the inlet end of the planar conveyor belt is arranged below the end of the baffle conveyor belt, and the narrowing structure is arranged on both sides of the outlet end of the planar conveyor belt. The narrowing structure is used to gather the walnuts to the middle of the planar conveyor belt and form a single row arrangement at the outlet end of the planar conveyor belt.

[0020] In a specific embodiment, the thin film piezoelectric sensor is a vibration sensor based on a PVDF piezoelectric film.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention uses a roller-type conveying mechanism, leaving a small length at the front end to allow the walnuts to adjust themselves to rotate around the seam as gravity during the rolling process, ensuring that the transverse diameter size is the only basis for passing the barrier rod, thereby improving the sorting accuracy and maintaining the high sorting efficiency of the roller-type sorting technology.

[0023] The present invention adopts a blocking rod method and utilizes the different transverse diameters of walnuts of different sizes to sort the walnuts by size. The walnuts are sorted using a rotating lever. The sorting is fast and the entire processing process is open and visible. Abnormal conditions can be handled in time, and the operation is simple and the maintenance cost is low.

[0024] The present invention uses a thin-film piezoelectric sensor to collect the vibration response signals of walnuts falling freely at the same height, converts the force signals into electrical signals through signal processing and analysis technology, and adopts the KNN discriminant algorithm to construct a discrimination model to distinguish between empty and full walnuts, thereby realizing non-destructive testing of the internal quality of walnuts.

[0025] The piezoelectric sensor used in this invention offers the advantages of high sensitivity and a wide dynamic range, particularly for detecting minute mechanical vibrations or pressure changes. Piezoelectric sensors have a dynamic range over 10 times greater than resistive piezoelectric sensors, resulting in a faster response, making them suitable for rapidly changing pressures. They also offer relatively improved stability and require no external power supply. Thin-film piezoelectric sensors, compared to traditional piezoelectric sensors, utilize ultra-thin piezoelectric materials, resulting in significantly improved sensitivity. These sensors are more suitable for detecting minute deformations while maintaining a high response speed.

[0026] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention is further described in detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0028] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0029] Figure 2 This is a schematic structural diagram of a bucket-shaped silo and a walnut size grading mechanism according to an embodiment of the present invention;

[0030] Figure 3 This is a schematic structural diagram of a combination of a baffle-type conveyor belt, a directional sorting mechanism, a piezoelectric sensing platform, a signal acquisition and processing system, and a host computer according to an embodiment of the present invention;

[0031] Figure 4 Schematic diagram of the forward direction of a walnut size grading mechanism according to an embodiment of the present invention;

[0032] Figure 5 1 is a schematic structural diagram of a piezoelectric sensing platform according to an embodiment of the present invention;

[0033] Figure 6 This is a detection flow chart of an embodiment of the present invention;

[0034] Figure 7 This is a flow chart for determining whether a walnut is full according to an embodiment of the present invention;

[0035] Figure 8 is a processing flow chart of a signal acquisition and processing system according to an embodiment of the present invention;

[0036] Among them, 1. Bucket-shaped silo; 2. Walnut size grading mechanism; 3. Baffle conveyor belt; 4. Directional sorting mechanism; 5. Piezoelectric sensing platform; 6. Signal acquisition and processing system; 7. Host computer; 8. Discharge channel. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] The present invention provides an intelligent detection device for internal defects of walnuts of various specifications, comprising a bucket-shaped silo 1, a walnut size grading mechanism 2, a baffle-type conveyor belt 3, a directional sorting mechanism 4, a piezoelectric sensing platform 5, a signal acquisition and processing system 6, and a host computer 7;

[0039] A walnut size grading mechanism 2 is provided below the outlet of the bucket-shaped silo 1. Different baffle-type conveyor belts 3 are provided corresponding to different outlets of the walnut size grading mechanism 2. A directional sorting mechanism 4 is provided below the outlet of the baffle-type conveyor belt 3. A piezoelectric sensing platform 5 is provided below the outlet of the directional sorting mechanism 4. The piezoelectric sensing platform 5 is connected to a signal acquisition and processing system 6, which is also connected to a host computer 7.

[0040] The piezoelectric sensing platform 5 includes a thin-film piezoelectric sensor, a shock-absorbing base platform, an anti-overflow baffle, and a push rod module; the shock-absorbing base platform includes a horizontally arranged square bottom plate; the thin-film piezoelectric sensor is adhesively arranged on the upper surface of the square bottom plate; the front and rear sides of the square bottom plate are respectively fixedly welded to the bottom edges of two anti-overflow baffles, the anti-overflow baffles are rectangular and vertically arranged, and the square bottom plate and the anti-overflow baffles on the front and rear sides form a U-shaped directional channel; push rod modules are arranged on both the left and right sides of the U-shaped directional channel, the push rod module includes a push plate, an electric push rod, and a push rod bracket, the base of the electric push rod is fixedly connected to the bottom of the square bottom plate through the push rod bracket, and the end of the telescopic end of the electric push rod is fixedly connected to the push plate; the push plates on the left and right sides, the square bottom plate, and the anti-overflow baffle group jointly enclose a box-shaped structure with an open upper part; there are gaps between the push plate and the square bottom plate and the anti-overflow baffle group, and the width of the gap is smaller than the diameter of the walnut, so that the walnut will not leak out through the gap.

[0041] The hopper-shaped bin includes a bin main body and a bin support, the bin main body is arranged on the bin support, the lower part of the bin main body is funnel-shaped, a bin discharge port is arranged at the bottom of the bin main body, and the bin discharge port includes a discharge plate with an adjustable inclination angle.

[0042] The walnut size grading mechanism includes a power roller conveyor, side baffles, grading stop bars, a dial rod, and a dial rod bracket;

[0043] The inlet end of the power roller conveyor is arranged below the hopper-shaped bin;

[0044] Side baffles are arranged on both sides of the roller of the power roller conveyor, and the side baffles are used to prevent walnuts from leaking out from the side;

[0045] The grading stop bars are horizontally arranged above the power roller conveyor, and the grading stop bars cooperate with the rollers of the power roller conveyor to grade the walnuts. At least two grading stop bars are arranged above the power roller conveyor, and the spacing height between the grading stop bar close to the inlet end of the power roller conveyor and the roller directly below it decreases in sequence; a roller is arranged directly below the grading stop bar,

[0046] A grading outlet is arranged on the side baffle, and the grading outlet is arranged at the end of the gap between the roller directly below the grading stop bar and the adjacent roller on the side close to the inlet end of the power roller conveyor;

[0047] A dial rod is arranged on the side of the grading stop bar close to the inlet end of the power roller conveyor, the dial rod corresponds to the grading outlet, and the dial rod is used to dial out the walnuts located below the dial rod from the grading outlet;

[0048] The dial rod is mounted on the power roller conveyor through the dial rod bracket, a dial rod motor is arranged on the dial rod bracket, the dial rod is connected to the dial rod motor, and the dial rod motor is used to rotate the dial rod.

[0049] The lever is a Y-shaped lever; the Y-shaped lever is an integrated lever composed of three spoon-shaped single rods with an angle of 120° between them; the speed of the lever motor is adjusted according to the transportation speed of the walnuts on the powered roller conveyor, thereby controlling the rotation frequency of the Y-shaped lever; when the Y-shaped lever is not rotating, two of the spoon-shaped single rods remain on both sides of the powered roller conveyor, so that the walnuts will not leak from the grading outlet; when the Y-shaped lever rotates, it rotates 120° each time.

[0050] Independent discharging channels 8 are provided below the grading outlet and the outlet end of the powered roller conveyor, which guide walnuts of different grades into different baffle conveyor belts respectively; the discharging channel 8 is a sloped curved slide, the upper end of the discharging channel 8 is connected to the grading outlet or the outlet end of the powered roller conveyor, and a baffle conveyor belt is provided below the lower end of the discharging channel 8.

[0051] The directional sorting mechanism includes a planar conveyor belt and a narrowing structure; the inlet end of the planar conveyor belt is arranged below the end of the baffle conveyor belt, and the narrowing structure is arranged on both sides of the outlet end of the planar conveyor belt. The narrowing structure is used to gather the walnuts to the middle of the planar conveyor belt and form a single row arrangement at the outlet end of the planar conveyor belt.

[0052] The thin film piezoelectric sensor is a vibration sensor based on a PVDF piezoelectric film.

[0053] Example 1

[0054] An intelligent detection device for internal defects of walnuts of various specifications, comprising a bucket-shaped silo, a walnut size grading mechanism, a baffle-type conveyor belt, a directional sorting mechanism, a piezoelectric sensing platform, a signal acquisition and processing system, and a host computer;

[0055] The bucket-shaped silo includes a silo body and a silo support. The silo body is mounted on the silo support. The lower portion of the silo body is funnel-shaped, and a silo discharge port is provided at the bottom of the silo body. The silo discharge port includes a discharge plate with an adjustable tilt angle. The instantaneous discharge flow rate of the bucket-shaped silo is adjusted by adjusting the tilt angle of the discharge plate. This ensures a continuous and stable supply of materials while preventing material congestion caused by excessive instantaneous flow. The material is evenly spread through the adjustable silo discharge port and accurately falls onto the surface of the powered roller conveyor below. As the powered roller conveyor rolls, the walnuts adjust their own direction and roll horizontally and are transported forward at a constant speed, thereby achieving orderly material input.

[0056] A walnut size grading mechanism is provided below the bucket-shaped silo, and is used to grade the walnuts according to their sizes.

[0057] The walnut size grading mechanism includes a powered roller conveyor, side baffles, grading baffles, a Y-shaped lever, and a Y-shaped lever bracket;

[0058] The inlet end of the powered roller conveyor is arranged below the bucket-shaped silo;

[0059] The power roller conveyor is equipped with side baffles on both sides of the roller to prevent walnuts from leaking out from the sides;

[0060] A grading bar is installed horizontally above the powered roller conveyor. It works in conjunction with the rollers to grade the walnuts. Both ends of the grading bar are mounted on adjustable bar brackets, which are installed on either side of the powered roller conveyor. Two grading bars are installed above the powered roller conveyor. The bar near the inlet of the powered roller conveyor is 34mm clear of the roller directly below it, while the bar near the outlet of the powered roller conveyor is 30mm clear of the roller directly below it.

[0061] A grading outlet is provided on the side baffle, which is arranged close to the grading baffle and located on the side of the grading baffle close to the inlet end of the powered roller conveyor. A roller is provided directly below the grading baffle. Preferably, the grading outlet is provided at the end of the gap between the roller directly below the grading baffle and the adjacent roller on the side of the roller close to the inlet end of the powered roller conveyor.

[0062] A Y-shaped lever is located on the side of the grading bar near the entrance of the powered roller conveyor. This lever matches the grading outlet and is used to remove walnuts below it from the grading outlet. The Y-shaped lever is an integrated lever consisting of three spoon-shaped single levers spaced 120 degrees apart.

[0063] The Y-shaped shifting rod is mounted on the power roller conveyor through a shifting rod bracket. A shifting rod motor is provided on the shifting rod bracket. The Y-shaped shifting rod is connected to the shifting rod motor. The shifting rod motor is used to rotate the Y-shaped shifting rod.

[0064] The Y-shaped lever's rotational frequency is controlled by adjusting the lever motor's speed based on the walnuts' transport speed on the powered roller conveyor. When the Y-shaped lever is stationary, its two spoon-shaped rods remain stationary on either side of the powered roller conveyor, ensuring the walnuts' smooth progress and preventing them from leaking out of the grading exit. As the Y-shaped lever rotates, each 120° rotation maintains the two spoon-shaped rods at the grading exit, preventing walnuts that don't meet size requirements from leaking out.

[0065] Walnuts come out of the bucket-shaped silo and fall into the entrance of the powered roller conveyor. As the roller on the powered roller conveyor rotates and moves forward, when they are transported to the first grading bar, walnuts with a diameter greater than or equal to 34mm are blocked in front of the first grading bar, while walnuts with a diameter less than 34mm will pass through the first grading bar smoothly and continue to move forward. When they are transported to the second grading bar, walnuts with a diameter greater than or equal to 30mm and less than 34mm are blocked in front of the second grading bar, while walnuts with a diameter less than 30mm will pass through the second grading bar smoothly and continue to move forward. The walnuts that pass through the second grading bar leave the powered roller conveyor from the exit end of the powered roller conveyor.

[0066] Through two grading outlets and the outlet end of the powered roller conveyor, the walnuts are divided into three levels: walnuts with a diameter greater than or equal to 34mm, walnuts with a diameter greater than or equal to 30mm and less than 34mm, and walnuts with a diameter less than 30mm.

[0067] Different discharge channels are located below the two grading outlets and the outlet of the powered roller conveyor, directing walnuts of different grades to different baffle conveyor belts. The discharge channels preferably utilize inclined curved slideways, with the upper ends of the discharge channels connected to the grading outlets or the outlet of the powered roller conveyor, and the lower ends of the discharge channels are provided with baffle conveyor belts.

[0068] The three discharge channels correspond to the three grades of walnuts: large, medium and small. The subsequent production lines form independent and identical production lines for each grade of walnuts.

[0069] The baffle conveyor belt realizes discrete material processing by separating independent units, forming standardized small-batch conveying units, effectively controlling the material flow per unit time to prevent material blockage.

[0070] A directional sorting mechanism is installed below the end of the baffle conveyor belt, which arranges the walnuts into a single file for transport. The upper and lower conveyors precisely dock at close range to prevent material from falling, and the seamless transition of the mechanical structure ensures continuous and stable material transportation.

[0071] The directional sorting mechanism includes a flat conveyor belt and a narrowing structure; the inlet end of the flat conveyor belt is arranged below the end of the baffle conveyor belt, and the narrowing structure is arranged on both sides of the outlet end of the flat conveyor belt. The narrowing structure is used to gather the walnuts to the middle of the flat conveyor belt and form a single row arrangement at the outlet end of the flat conveyor belt.

[0072] The narrowing structure is composed of two baffles that converge toward the center of the flat conveyor belt.

[0073] A piezoelectric sensing platform is provided below the end of the directional sorting mechanism; the piezoelectric sensing platform is used to sort out the shriveled walnuts.

[0074] The piezoelectric sensing platform includes a thin-film piezoelectric sensor, a shock-absorbing base platform, an anti-overflow baffle, and a push rod module;

[0075] The thin-film piezoelectric sensor is adhesively disposed on the upper surface of the shock-absorbing base platform. The shock-absorbing base platform includes a horizontally arranged square bottom plate with a side length of 0.1 m and legs fixedly arranged below the square bottom plate. The square bottom plate is a stainless steel plate. The thin-film piezoelectric sensor is a vibration sensor based on PVDF piezoelectric film. In this embodiment, the LDT0-028K piezoelectric sensor designed based on PVDF is used as the sorting core device.

[0076] The front and rear sides of the square bottom plate are respectively fixedly welded to the bottom edges of two anti-overflow baffles. The anti-overflow baffles are rectangular and vertically arranged, with a height of 0.1 m. The square bottom plate and the anti-overflow baffles on the front and rear sides form a U-shaped directional channel.

[0077] Push rod modules are arranged on both the left and right sides of the U-shaped directional channel. The push rod module includes a push plate and an electric push rod. The base of the electric push rod is fixedly connected to the bottom of the square bottom plate through a bracket, and the end of the telescopic end of the electric push rod is fixedly connected to the push plate; the push plates on both the left and right sides and the square bottom plate and the anti-overflow baffles on the front and rear sides jointly enclose a box-like structure with an open upper part; there are gaps between the push plate and the square bottom plate and the anti-overflow baffle group, and the width of the gap is smaller than the diameter of the walnut, so that the walnut will not leak out through the gap.

[0078] The push plates in the push rod modules on both the left and right sides cooperate with each other through the electric push rods connected to them respectively, so as to achieve mechanical linkage. That is, the upper computer controls the electric push rods on both sides to achieve that when the left push plate moves to the left, the right push plate also moves to the left synchronously; when the left push plate moves to the right, the right push plate also moves to the right synchronously.

[0079] Both the thin-film piezoelectric sensor and the electric push rod are connected to the signal acquisition and processing system, and the signal acquisition and the signal acquisition and processing system are also connected to the upper computer;

[0080] The thin-film piezoelectric sensor sends the vibration signal generated when the walnut falls on it to the signal acquisition and processing system. The signal acquisition and processing system processes the received vibration signal and converts it into an electrical signal and then transmits it to the upper computer.

[0081] The upper computer judges whether the walnut is shriveled and issues a sorting instruction to the signal acquisition and processing system. After receiving the sorting instruction from the upper computer, the signal acquisition and processing system controls the electric push rod to execute a preset stroke. The telescopic end of the electric push rod drives the push plate to perform a horizontal displacement of 0.1 m to the left / right, and pushes the falling walnut to slide into the corresponding aggregate bin along a predetermined trajectory, completing the directional sorting operation.

[0082] After receiving the sorting instructions from the host computer, the control system drives the push rod to execute the preset stroke, driving the push plate assembly to move horizontally 0.1m to the left / right along the guide rail pair, and relying on friction to guide the walnuts along the predetermined trajectory into the corresponding collection bin to complete the directional sorting operation.

[0083] The signal acquisition and processing system consists of a preamplifier, a filter, an A / D converter, and an FPGA signal processing module. It is connected to the piezoelectric film sensor, receives the vibration signal, processes it, converts it into an electrical signal, and then transmits it to the host computer.

[0084] The upper computer receives and displays the processed electrical signal results in real time. After data classification using the K-Nearest Neighbors (KNN) algorithm, it sends a signal to the servo motor, driving the electric push rod to perform left / right movements and then feedback to the system, completing the classification of the walnut as empty / shrunken, or full, and then proceeding to the next walnut classification.

[0085] The specific detection methods are:

[0086] When walnuts fall onto the piezoelectric sensing platform, they vibrate, and a charge amplifier amplifies the signal. A signal acquisition card receives the amplified signal and converts it into an electrical signal. The host computer then uses an algorithm, preferably a KNN algorithm, to determine the walnuts. Based on the Xinjiang walnut grading standards, walnut samples are defined as plump walnuts weighing ≥10g, and shriveled, empty walnuts weighing 5-10g. After conversion to an electrical signal, a voltage peak range of ≥4V is defined as plump walnuts. This signal is transmitted to the servo motor, driving the push rod to perform the right-side sorting operation. Other walnuts are defined as shriveled or empty walnuts, and no distinction is made between them. This signal is then transmitted to the motor, driving the push rod to perform the left-side sorting operation.

[0087] Because the average weights of large, medium, and small walnuts vary considerably, the peak values set for the sensors on the three production lines need to be adjusted based on the actual average weights of the walnut varieties. However, the weight difference between empty, shrunken, and plump walnuts is much greater than the weight difference between the three types of walnuts, regardless of whether they are large, medium, or small. Therefore, even if the peak value of the electrical signal is set based on the average weight, the likelihood of misjudging internal defects is low.

[0088] The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, several simple deductions and substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the scope of protection of the present invention.

Claims

1. An intelligent detection device for internal defects of walnuts of various specifications, characterized in that: It includes a hopper-shaped bin, a walnut size grading mechanism, a baffle conveyor belt, an orientation sorting mechanism, a piezoelectric sensing platform, a signal acquisition and processing system, and a host computer; Below the outlet of the hopper-shaped bin, there is a walnut size grading mechanism. Different outlets of the walnut size grading mechanism are respectively provided with different baffle conveyor belts. Below the outlets of the baffle conveyor belts, there are orientation sorting mechanisms. Below the outlets of the orientation sorting mechanisms, there are piezoelectric sensing platforms. The piezoelectric sensing platforms are all connected to the signal acquisition and processing system, and the signal acquisition and processing system is also connected to the host computer; The piezoelectric sensing platform includes a thin-film piezoelectric sensor, a shock-absorbing base platform, an anti-overflow baffle, and a push rod module; The shock-absorbing base platform includes a horizontally arranged square bottom plate; The thin-film piezoelectric sensor is adhesively arranged on the upper surface of the square bottom plate; The front and rear sides of the square bottom plate are respectively fixedly welded to the bottom edges of two anti-overflow baffles. The anti-overflow baffles are rectangular and vertically arranged. The square bottom plate and the anti-overflow baffles on the front and rear sides form a U-shaped orientation channel; On both sides of the U-shaped orientation channel, there are push rod modules. The push rod module includes a push plate, an electric push rod, and a push rod support. The base of the electric push rod is fixedly connected to the bottom of the square bottom plate through the push rod support, and the end of the telescopic end of the electric push rod is fixedly connected to the push plate; The push plates on both sides, together with the square bottom plate and the anti-overflow baffle group, enclose a box-shaped structure with an open upper part; There are gaps between the push plate and the square bottom plate and the anti-overflow baffle group, and the width of the gap is less than the diameter of the walnut, so that the walnut will not leak out through the gap.

2. The intelligent detection device for internal defects of walnuts of multiple specifications according to claim 1 is characterized in that: The hopper-shaped bin includes a bin main body and a bin support. The bin main body is arranged on the bin support. The lower part of the bin main body is funnel-shaped. There is a bin discharge port at the bottom of the bin main body. The bin discharge port includes a discharge plate with an adjustable inclination angle.

3. The intelligent detection device for internal defects of walnuts of multiple specifications according to claim 1 is characterized in that: The walnut size grading mechanism includes a power roller conveyor, side baffles, grading bars, a dialing rod, and a dialing rod support; The inlet end of the power roller conveyor is arranged below the hopper-shaped bin; Side baffles are arranged on both sides of the roller of the power roller conveyor. The side baffles are used to prevent walnuts from leaking out from the side; The grading bars are horizontally arranged above the power roller conveyor. The grading bars cooperate with the rollers of the power roller conveyor to grade walnuts. There are at least two grading bars above the power roller conveyor, and the spacing height between the grading bar closest to the inlet end of the power roller conveyor and the roller directly below it decreases in sequence; There is a roller directly below the grading bar, There is a grading outlet on the side baffle. The grading outlet is arranged at the end of the gap between the roller directly below the grading bar and the adjacent roller on the side close to the inlet end of the power roller conveyor; A dialing rod is arranged on the side of the grading bar close to the inlet end of the power roller conveyor. The dialing rod is matched with the grading outlet. The dialing rod is used to dial out the walnuts located below the dialing rod from the grading outlet; The dialing rod is erected on the power roller conveyor through the dialing rod support. There is a dialing rod motor on the dialing rod support. The dialing rod is connected to the dialing rod motor. The dialing rod motor is used to make the dialing rod rotate.

4. The intelligent detection device for internal defects of walnuts of multiple specifications according to claim 3 is characterized in that: The lever is a Y-shaped lever; the Y-shaped lever is an integrated lever composed of three spoon-shaped single rods with an angle of 120° between them; the speed of the lever motor is adjusted according to the transportation speed of the walnuts on the powered roller conveyor, thereby controlling the rotation frequency of the Y-shaped lever; when the Y-shaped lever is not rotating, two of the spoon-shaped single rods remain on both sides of the powered roller conveyor, so that the walnuts will not leak from the grading outlet; when the Y-shaped lever rotates, it rotates 120° each time.

5. The intelligent detection device for internal defects of walnuts of multiple specifications according to claim 4 is characterized in that: Independent discharging channels are provided below the grading outlet and the outlet end of the powered roller conveyor, which guide walnuts of different grades into different baffle conveyor belts respectively; the discharging channel is a sloped curved slide, the upper end of the discharging channel is connected to the grading outlet or the outlet end of the powered roller conveyor, and a baffle conveyor belt is provided below the lower end of the discharging channel.

6. The intelligent detection device for internal defects of walnuts of various specifications according to claim 1 is characterized in that: The directional sorting mechanism includes a planar conveyor belt and a narrowing structure; the inlet end of the planar conveyor belt is arranged below the end of the baffle conveyor belt, and the narrowing structure is arranged on both sides of the outlet end of the planar conveyor belt. The narrowing structure is used to gather the walnuts to the middle of the planar conveyor belt and form a single row arrangement at the outlet end of the planar conveyor belt.

7. The intelligent detection device for internal defects of walnuts of various specifications according to claim 1 is characterized in that: The thin film piezoelectric sensor is a vibration sensor based on a PVDF piezoelectric film.

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