Knocking device for detecting meat freshness based on knocking method and meat freshness detection method

Abstract

The invention provides a knocking device for detecting meat freshness based on a knocking method and a meat freshness detection method. The knocking device for detecting the meat freshness based on the knocking method comprises a supporting frame, a traction piece, a knocking assembly, a detection assembly and an elastic piece. The support frame is provided with a top mounting table and a middle mounting table; the knocking assembly comprises a knocking rod, the knocking rod is in up-down sliding fit with the middle mounting table, and a lower magnet is arranged at the top of the knocking rod; the traction piece is arranged on the upper side of the top mounting table, a liftable traction end is formed at the bottom end of the traction piece, and an upper magnet is arranged at the traction end; and the elastic piece is arranged between the periphery of the knocking rod and the middle mounting table. According to the knocking device for detecting the meat freshness based on the knocking method, the upper magnet and the lower magnet drive the knocking rod to move, the elastic piece drives the knocking rod to move downwards, the springback acting force of the knocking rod cannot be transmitted to the traction piece, and the problem of repeated knocking cannot occur.

Description

Technical Field

[0001] The present application belongs to the technical field of food detection, and specifically relates to a knocking device for detecting the freshness of meat based on a knocking method and a meat freshness detection method. Background Art

[0002] Meat has high nutritional value, can be prepared in many ways, and has rich cooking flavors. It is deeply loved by consumers and has a large market demand. The freshness of meat greatly affects the taste and flavor of meat products. In order to ensure the taste and safety of meat, the freshness of meat needs to be tested.

[0003] There are two traditional methods for detecting meat freshness. One is to use an odor sensor to detect the volatile gases emitted by meat to judge the freshness of meat. This method requires continuous detection of volatile gases emitted by meat, which takes a long time. In addition, the odor sensor needs to be measured by employees in hand, which is affected by employee operation, has large detection location limitations, and low detection accuracy. The other is to use fluorescence hyperspectral detection. By obtaining the potential fluorescent marker content and freshness index data of fresh meat, a prediction model is constructed to determine the freshness. Building the model is time-consuming, difficult, and complex to operate, and it requires high technical skills from the inspectors. Summary of the Invention

[0004] The embodiments of the present application provide a knocking device and a meat freshness detection method for detecting the freshness of meat based on the knocking method, aiming to solve the technical problems in the prior art of low accuracy of using odor sensors to detect the freshness of meat, great difficulty in using fluorescence hyperspectral method to detect the freshness of meat, and high technical requirements of employees for both methods.

[0005] To achieve the above objectives, the technical solution adopted in this application is: In a first aspect, a percussion device for detecting the freshness of meat based on a percussion method is provided, comprising: A support frame having a top mounting platform and a middle mounting platform spaced apart from top to bottom; A knocking assembly includes a knocking rod, the knocking rod is slidably matched with the middle mounting platform, the bottom end of the knocking rod forms a knocking end, and the top of the knocking rod is provided with a lower magnet; The upper magnet can absorb and drive the lower magnet to rise, so as to make the knocking rod rise; The lower portion of the top mounting platform can abut against the lower magnet to limit the upward displacement of the lower magnet, so as to separate the lower magnet from the upper magnet; A traction member is provided on the upper side of the top mounting platform, wherein the bottom end of the traction member forms a traction end that can be raised and lowered, and the traction end is provided with an upper magnet, wherein the magnetic poles of the upper magnet and the lower magnet are opposite; a detection assembly for obtaining the vibration frequency and decay time of the meat sample; and The elastic member is arranged between the outer periphery of the knocking rod and the middle mounting platform and is configured with a pre-tightening force for pushing the knocking rod to descend.

[0006] In combination with the first aspect, in a possible implementation, an upper clamping platform is provided on the upper part of the knocking rod, a lower clamping platform is provided on the lower part of the knocking rod, the elastic member is provided between the middle mounting platform and the lower clamping platform, the bottom of the elastic member abuts against the lower clamping platform, the top of the elastic member abuts against the middle mounting platform, and the lower magnet is installed on the upper clamping platform.

[0007] In combination with the first aspect, in a possible implementation, a limit plate is provided on the top mounting platform, the lower side of the limit plate can abut against the lower magnet, and an avoidance channel is formed in the middle of the limit plate, and the traction end slides through the avoidance channel.

[0008] In combination with the first aspect, in a possible implementation, the traction member includes: a traction motor, disposed on the top mounting platform and having a transversely extending output shaft; an output gear coaxially fixed to the output shaft; and The rack is vertically arranged and meshes with the output gear. A limiting hole for the output gear to slide through is opened on the top mounting platform, and the bottom end of the rack forms the traction end.

[0009] In combination with the first aspect, in a possible implementation, the detection component includes an acceleration sensor, which is placed on the meat sample and is used to detect the vibration frequency and decay time of the meat sample.

[0010] In combination with the first aspect, in a possible implementation, the knocking assembly also includes a connecting platform and a knocking hammer, the connecting platform is fixed on the middle mounting platform, the middle part of the connecting platform has a sliding hole that passes through the upper and lower parts, and the knocking rod slides through the sliding hole; the knocking hammer is arranged at the bottom of the knocking rod and forms the knocking end.

[0011] In combination with the first aspect, in a possible implementation, an articulated arm is provided on the outer side of the middle mounting platform, and the articulated axis is parallel to the horizontal direction. A laser locator is installed at the free end of the articulated arm, and the laser locator is used to calibrate the falling position of the knocking rod.

[0012] In combination with the first aspect, in one possible implementation, the elastic member is a spring sleeved on the outer circumference of the knocking rod, and the knocking device for detecting the freshness of meat based on the knocking method further includes an adjustment component, which includes: an adjusting driving member, mounted on the bottom of the top mounting platform, wherein the bottom end of the adjusting driving member forms a rotatable output end, and the rotation axis is parallel to the vertical direction; A rotating support is mounted on the middle mounting platform, wherein a lifting channel is formed in the middle of the rotating support for the striking rod to move up and down; an adjusting knob, sleeved on the outer periphery of the rotating support and threadedly connected to the rotating support, an adjusting groove being provided inside the adjusting knob corresponding to the lifting channel, and an inner wall of the adjusting groove being connected to the top end of the elastic member; and The belt is simultaneously sleeved on the outer periphery of the adjusting knob and the output end of the adjusting drive member to achieve synchronous movement of the adjusting knob and the output end of the adjusting drive member.

[0013] In combination with the first aspect, in a possible implementation, a limit plate is provided at the bottom of the support frame, a limit hole is provided on the limit plate for the knocking rod to pass through up and down, an elastic limit member and a limit ring are provided between the limit plate and the lower clamping table, the elastic limit member is sleeved on the outer periphery of the knocking rod, and the bottom end of the limit ring can abut against the limit plate up and down.

[0014] The knocking device provided by the present application for detecting the freshness of meat based on the knocking method uses a traction part to drive the upper magnet to move up and down, and the upper magnet and the lower magnet are attracted to each other, so that the knocking rod moves up and down with the traction end, and the knocking rod compresses the elastic part, and the limiting part limits the lower magnet, and the upper magnet and the lower magnet are separated. The elastic part recovers and drives the knocking rod to move downward, thereby realizing the knocking operation. The upper magnet and the lower magnet are cleverly used to realize the automatic separation or connection of the knocking rod and the traction end, without the need for manual connection by employees, thereby improving the use efficiency; the upper magnet and the lower magnet drive the knocking rod to move, giving power to the elastic part, and the elastic part drives the knocking rod to move downward, and the knocking rod The rebound force will not be transmitted to the traction part, and the effect of a single knock can be achieved without the problem of repeated knocking. The traction part is not affected by the reaction force, which reduces the use loss and extends the service life of the traction part; it will not significantly damage the structure of the meat sample, and the test can be repeated at the same position of the meat sample, which can improve the detection accuracy; compared with the method of using an odor sensor to detect volatile gases in meat, this application does not require continuous detection of volatile gases, which greatly shortens the detection time. At the same time, it is not affected by the handheld operation of employees, and overcomes the shortcomings of large detection position limitations and low detection accuracy. Compared with the detection method using fluorescence hyperspectral method, this knocking device does not have the problems of time-consuming and difficult model construction, complex operation, and high technical requirements for inspectors.

[0015] In a second aspect, a method for detecting meat freshness is provided, which is implemented based on a percussion device for detecting meat freshness based on a percussion method as described in any of the possible implementations above, and includes the following steps: S1: Start the traction part and move the traction end downward until the upper magnet and the lower magnet are attracted and connected; S2: The traction end rises, driving the knocking rod to rise; S3: The knocking rod continues to rise. After the lower magnet contacts the lower part of the top mounting platform, the pulling end continues to rise. The upper and lower magnets separate. The knocking rod accelerates downward under the action of the elastic member, and the knocking end contacts the meat sample. S4: Use the detection component to obtain the vibration frequency f of the meat sample and obtain the decay time : S5: Using decay time And the vibration frequency f are used to calculate the sample freshness score using the formula:

[0016] If the score is <70, the meat sample is considered spoiled; If the score is ≥70, the meat sample is judged.

[0017] The meat freshness detection method provided by the present application does not need to destroy the meat sample compared with the prior art. The traction part is used to drive the upper magnet to move up and down. The upper magnet and the lower magnet are attracted to each other, so that the knocking rod moves up and down with the traction end. The knocking rod compresses the elastic part, and the limiting part limits the lower magnet. The upper magnet and the lower magnet are separated, and the elastic part recovers and drives the knocking rod to move downward to realize the knocking operation. The upper and lower magnets are cleverly used to realize the automatic separation or connection of the knocking rod and the traction end, without the need for manual connection by employees, thereby improving the use efficiency; the upper and lower magnets drive the knocking rod to move, giving power to the elastic part, and the elastic part drives the knocking rod to move downward. The rebound force of the knocking rod will not be transmitted to the traction part, and a single knocking operation can be achieved. The traction part is not affected by the reaction force, which reduces the use loss and extends the service life of the traction part; it will not greatly damage the structure of the meat sample, and the test can be repeated at the same position of the meat sample, which can improve the detection accuracy; the freshness of the meat sample is calculated by the attenuation time and vibration frequency of the meat sample vibration, without destroying the sample, reducing cost waste; knocking on various positions of the meat sample ensures that the data obtained is highly reliable, and knocking on the meat sample in all aspects improves the detection accuracy; the knocking rod drives the knocking hammer to knock the meat sample downward, which can quickly obtain the vibration frequency and attenuation time of the meat sample, shortening the acquisition time and improving the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] Figure 1 This is a schematic diagram of the main structure of a knocking device for detecting meat freshness based on a knocking method provided in one embodiment of the present application; Figure 2 for Figure 1 A schematic diagram of the structure of the striking component and the regulating component used in the embodiment; Figure 3 for Figure 2 An enlarged view of A used in ; Figure 4 This is a schematic diagram of the structure of an acceleration sensor used in one embodiment of the present application.

[0020] Description of reference numerals: 1. Support frame; 11. Top mounting platform; 12. Middle mounting platform; 121. Articulated arm; 13. Limit plate; 2. Traction member; 21. Traction motor; 22. Output gear; 23. Rack; 24. Upper magnet; 3. Striking assembly; 31. Connecting platform; 32. Striking rod; 321. Upper clamping platform; 322. Lower clamping platform; 33. Striking hammer; 34. Lower magnet; 4. Elastic parts; 5. Laser locator; 6. Adjustment assembly; 61. Adjustment drive member; 62. Rotary support; 63. Adjustment knob; 64. Belt; 7. Elastic limiter; 8. Acceleration sensor; 81. Pin. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0023] It should be noted that the terms "length," "width," "height," "thickness," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," "head," and "tail" and the like, indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the application. The directional terms "inside" and "outside" refer to the inside and outside relative to the outline of the component itself.

[0024] It should also be noted that, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," "fixed," and "set" should be understood broadly. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and may encompass internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referenced. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Furthermore, "plurality" and "several" mean two or more, unless otherwise specifically defined.

[0026] Please also refer to Figures 1 to 4The present invention provides a knocking device for detecting the freshness of meat based on the knocking method. The knocking device for detecting the freshness of meat based on the knocking method includes a support frame 1, a traction member 2, a knocking component 3, a detection component and an elastic member 4. The support frame 1 has a top mounting platform 11 and a middle mounting platform 12 spaced apart from top to bottom; the knocking assembly 3 includes a knocking rod 32, which slides up and down with the middle mounting platform 12, the bottom end of the knocking rod 32 forms a knocking end, and the top of the knocking rod 32 is provided with a lower magnet 34; the upper magnet 24 can adsorb and drive the lower magnet 34 to rise, so that the knocking rod 32 rises; the lower part of the top mounting platform 11 can abut against the lower magnet 34 to limit the upward displacement of the lower magnet 34, so that the lower magnet 34 is separated from the upper magnet 24; the traction member 2 is provided on the upper side of the top mounting platform 11, and the bottom end of the traction member 2 forms a liftable traction end, and the traction end is provided with an upper magnet 24, and the magnetic poles of the upper magnet 24 and the lower magnet 34 are opposite; the detection assembly is used to obtain the vibration frequency and decay time of the meat sample; the elastic member 4 is provided between the outer periphery of the knocking rod 32 and the middle mounting platform 12, and is configured with a preload force to push the knocking rod 32 down.

[0027] In specific implementation, the elastic member 4 is a spring. The spring has high elasticity, high strength, and a wide source, and can meet the needs of the elastic member 4. Of course, other elastic components, such as rubber tubes, can also be used. As long as they can be configured to exert a force to move the knock rod 32 downward when the knock rod 32 rises, they will not be listed one by one here.

[0028] It should be noted that the top mounting platform 11 is provided with an avoidance opening to ensure that the traction end can move up and down smoothly, and the middle mounting platform 12 is provided with an avoidance opening to ensure that the knocking rod 32 can move up and down smoothly.

[0029] Specifically, the support frame 1 is set up on a laboratory table, and a platform for placing meat samples is set on the laboratory table.

[0030] It should be noted that the knocking device used in this embodiment to detect the freshness of meat based on the knocking method obtains the required experimental data by knocking on the meat sample. The fresher the meat, the firmer the meat. By knocking on the meat sample, the vibration frequency and decay time of the meat sample are obtained, and the freshness can be evaluated.

[0031] The knocking device for detecting the freshness of meat based on the knocking method provided in this embodiment, compared with the prior art, uses the traction part 2 to drive the upper magnet 24 to move up and down, the upper magnet 24 and the lower magnet 34 are attracted, so that the knocking rod 32 moves upward with the traction end, and the knocking rod 32 compresses the elastic part 4, and the limit part abuts against the lower magnet 34 up and down, the upper magnet 24 and the lower magnet 34 are separated, and the elastic part 4 recovers and drives the knocking rod 32 to move downward, and the knocking end contacts the meat sample to realize the knocking operation, and the upper magnet 24 and the lower magnet 34 are cleverly used to realize the automatic separation or connection of the knocking rod 32 and the traction end, without the need for manual connection by employees, thereby improving the use efficiency; the upper magnet 24 and the lower magnet 34 drive the knocking rod 32 to move , giving power to the elastic member 4, the elastic member 4 drives the knocking rod 32 to move downward, and the rebound force of the knocking rod 32 will not be transmitted to the traction member 2, which can achieve the effect of a single knock, and there will be no problem of repeated knocking. The traction member 2 is not affected by the reaction force, which reduces the use loss and extends the service life of the traction member 2; it will not significantly damage the structure of the meat sample, and repeated tests can be performed at the same position of the meat sample, which can improve the detection accuracy; compared with the method of using an odor sensor to detect volatile gases in meat, the present application does not require continuous detection of volatile gases, greatly shortens the detection time, and is not affected by the handheld operation of employees, overcoming the shortcomings of large detection position limitations and low detection accuracy. Compared with the detection using fluorescence hyperspectral method, the knocking device does not have the problems of time-consuming and difficult model construction, complex operation, and high technical requirements for inspectors.

[0032] In some embodiments, see Figure 2 and Figure 3 The upper portion of the knocking rod 32 is provided with an upper retaining plate 321, and the lower portion of the knocking rod 32 is provided with a lower retaining plate 322. The elastic member 4 is disposed between the middle mounting plate 12 and the lower retaining plate 322. The bottom of the elastic member 4 abuts against the lower retaining plate 322, and the top of the elastic member 4 abuts against the middle mounting plate 12. The lower magnet 34 is mounted on the upper retaining plate 321. The bottom end of the elastic member 4 is connected to the top of the lower retaining plate 322. This connection is stable and reliable, ensuring that the knocking rod 32 descends stably and controllably, thereby ensuring consistent force on the meat sample.

[0033] For specific implementation, see Figure 2 The upper clamping platform 321 and the lower clamping platform 322 are respectively located on the upper and lower sides of the middle mounting platform 12. The middle mounting platform 12 can assist in limiting the moving range of the knocking rod 32.

[0034] In some embodiments, see Figure 2, a limit plate 13 is also provided on the top mounting platform 11. The lower part of the limit plate 13 can abut against the lower magnet 34. The middle part of the limit plate 13 forms an avoidance channel, and the traction end slides through the avoidance channel. The limit plate 13 can limit the upper clamping platform 321 from continuing to move upward, assisting the separation of the upper magnet 24 and the lower magnet 34, and facilitating the resetting of the elastic member 4; the bottom surface of the limit plate 13 and the upper surface of the upper clamping platform 321 are clamped up and down, which can effectively limit the displacement range of the knocking rod 32 in the vertical direction. This not only ensures the stability of the knocking rod 32 during the knocking process, preventing it from excessive movement affecting the knocking effect, but also ensures that the position of each knock is relatively fixed, thereby improving the repeatability and accuracy of the detection and making the detection results more credible.

[0035] For specific implementation, see Figure 1 and Figure 2 The top mounting platform 11 and the middle mounting platform 12 are both arc-shaped mounting platforms. The limiting plate 13 is installed in the top mounting platform 11 . The traction member 2 is installed on the top mounting platform 11 and is located above the limiting plate 13 .

[0036] In some embodiments, see Figure 1 and Figure 2 The traction member 2 includes a traction motor 21, an output gear 22, and a rack 23. The traction motor 21 is mounted on the top mounting platform 11 and has a transversely extending output shaft. The output gear 22 is coaxially fixed to the output shaft. The rack 23 is vertically arranged and meshes with the output gear 22. The top mounting platform 11 has a retaining hole for the output gear 22 to slide through. The bottom end of the rack 23 forms the traction end.

[0037] In this embodiment, the traction motor 21 drives the output gear 22 to rotate about its axis of rotation, thereby driving the rack 23 up and down. This gear-rack 23 transmission method smoothly converts the motor's rotational motion into linear motion, ensuring the accuracy and stability of the traction end's lifting and lowering movements, and reducing errors and jitter during movement. The traction motor 21 is easily integrated with an automated control system, automating the entire inspection process, improving inspection efficiency, and reducing errors that may be caused by manual intervention.

[0038] In some embodiments, see Figure 4 The detection assembly includes an accelerometer 8, which is placed on the meat sample and is used to detect the vibration frequency and decay time of the meat sample. Accelerometer 8 can directly detect the velocity information related to the impact of the falling knock rod 32 on the sample, obtaining relevant data to facilitate subsequent calculation and analysis of the meat sample's freshness.

[0039] In a specific implementation, the acceleration sensor 8 is fixed to the meat sample. As one connection method, the bottom of the acceleration sensor 8 is provided with a pin 81, and the tip of the pin 81 is provided with a barb. The pin 81 is inserted into the meat sample to fix the acceleration sensor 8.

[0040] As an optimization of acceleration sensor 8, the surface of pin 81 is coated with diamond-like carbon (DLC) (friction coefficient <0.1). Acceleration sensor 8 uses a PCB 352C33 accelerometer (range ±500g, sensitivity 10mV / g).

[0041] As another embodiment of the acceleration sensor 8, the FC-352C33 sensor may also be used, as long as it can detect the vibration frequency and decay time of the meat sample.

[0042] In some embodiments, see Figure 2 The striking assembly 3 also includes a connecting platform 31 and a striking hammer 33. The connecting platform 31 is fixed to the central mounting platform 12. The central portion of the connecting platform 31 has a sliding hole extending vertically therethrough, through which the striking rod 32 slides. The striking hammer 33 is located at the bottom of the striking rod 32 and forms a striking end. The connecting platform 31 increases the contact area between the striking rod 32 and the central connecting platform 12, improving the stability of the striking rod 32's movement. The striking hammer 33 is located at the bottom of the striking rod 32, increasing the contact area and enabling more stable and effective striking of meat samples, facilitating data acquisition.

[0043] In some embodiments, a shock-absorbing pad is provided at the bottom end of the hammer 33. The shock-absorbing pad can effectively cushion the impact force generated during the hammering, reduce the noise generated during the hammering process, prevent damage to the meat sample caused by excessive hammering, and ensure the integrity of the sample during the testing process. It can also reduce the vibration impact on the hammer 33 and other components of the entire hammering device, reduce wear and damage to components, extend the service life of the equipment, and reduce maintenance costs.

[0044] In some embodiments, see Figure 1 , an articulated arm 121 is provided on the outside of the middle mounting platform 12, and the articulated axis is parallel to the horizontal direction. A laser locator 5 is installed on the free end of the articulated arm 121. The laser locator 5 is used to calibrate the falling position of the knocking rod 32. The laser locator 5 can accurately indicate the specific position of the knocking before knocking, effectively avoiding the influence of the knocking position deviation on the detection result, and improving the accuracy of the knocking; through the laser spot to provide intuitive visual guidance, the operator can understand the knocking position more clearly, which is convenient for accurately placing the meat sample during the operation and reducing the detection error caused by human misjudgment. The articulated arm 121 can swing, driving the position of the laser locator 5 to change, making it convenient for employees to adjust the position of the laser spot and increasing the flexibility of use.

[0045] In a specific implementation, the laser locator 5 can use a 635nm red laser module (output power 1mW, Class 2M safety level), with a beam divergence angle of less than 0.5mrad and a spot diameter of ≤1mm.

[0046] In some embodiments, see Figure 1 and Figure 2 The elastic member 4 is a spring sleeved on the outer periphery of the knocking rod 32. The knocking device for detecting the freshness of meat based on the knocking method also includes an adjustment component 6, which includes an adjustment drive member 61, a rotating support 62, an adjustment knob 63, and a belt 64. The adjustment drive member 61 is installed at the bottom of the top mounting platform 11. The bottom end of the adjustment drive member 61 forms a rotatable output end, and the rotation axis is parallel to the vertical direction; the rotating support 62 is installed on the middle mounting platform 12, and the middle part of the rotating support 62 is formed with a lifting channel for the knocking rod 32 to move up and down; the adjustment knob 63 is sleeved on the outer periphery of the rotating support 62 and is threadedly connected to the rotating support 62. The interior of the adjustment knob 63 is provided with an adjustment groove corresponding to the lifting channel, and the inner wall of the adjustment groove is connected to the top of the elastic member 4; the belt 64 is sleeved on the outer periphery of the adjustment knob 63 and the output end of the adjustment drive member 61 at the same time to achieve synchronous movement of the adjustment knob 63 and the output end of the adjustment drive member 61.

[0047] During specific implementation, the adjustment drive member 61 adopts a reduction motor.

[0048] The working principle of this embodiment is as follows: the bottom rotating end of the adjusting drive member 61 starts to rotate, and the rotating axis is parallel to the vertical direction, and the adjusting knob 63 is driven to rotate through the belt 64. Because the adjusting knob 63 is threadedly connected to the rotating support 62, the adjusting knob 63 will move up and down along the axis when it rotates. The top of the elastic member 4 is close to the top inside the adjusting knob 63, and the up and down movement of the adjusting knob 63 directly drives the elastic member 4 to move synchronously, thereby changing the compression deformation of the elastic member 4. When the lower card table 322 applies compression to the elastic member 4, the elastic potential energy stored in the elastic member 4 changes accordingly. Finally, in the process of the knocking rod 32 knocking downward, the elastic potential energy stored in the elastic member 4 is converted into the kinetic energy of the knocking rod 32. By adjusting the size of the elastic potential energy, the precise adjustment of the knocking kinetic energy of the knocking rod 32 is achieved.

[0049] The coordinated operation of the adjustment driver 61, belt 64, adjustment knob 63, and rotating support 62 enables precise control of the axial position of the adjustment knob 63, adjusting the initial extension length of the elastic member 4 and, consequently, the elastic force of the elastic member 4. The length of the elastic member 4 can be flexibly adjusted based on the thickness and placement of different meat samples, making the tapping operation more adaptable to various samples and enhancing the versatility and applicability of the device. The belt 64 drives the adjustment knob 63 and the adjustment driver 61 to move synchronously, increasing the ease of adjustment.

[0050] In some embodiments, see Figure 1 and Figure 2 A limit plate is provided at the bottom of the support frame 1, and a limit hole is provided on the limit plate for the knocking rod 32 to pass through up and down. An elastic limiter 7 and a limit ring are provided between the limit plate and the lower clamping platform 322. The elastic limiter 7 is sleeved on the outer periphery of the knocking rod 32, and the bottom end of the limit ring can abut against the limit plate up and down. By installing the elastic limiter 7 at the end of the knocking rod 32 away from the middle mounting platform 12, part of the remaining kinetic energy after knocking once is converted into the elastic potential energy of the elastic limiter 7, thereby realizing a single independent knock. The setting of the elastic limiter 7 plays a dual role of buffering and positioning. During the knocking process, it can absorb part of the impact force, reduce damage to other parts of the device, and extend the service life of the device. At the same time, by abutting the limit ring against the limit plate up and down, the travel range of the knocking rod 32 is further limited, so that the force and position of each knock are repeatable; the limiting structure is relatively simple and convenient for assembly and disassembly of the device. When the striking device needs to be maintained, cleaned or parts replaced, the relevant parts can be operated conveniently, which improves the maintainability of the equipment and reduces maintenance costs and time costs.

[0051] The following is the specific working process provided by this embodiment: When using the percussion method to test pork freshness, once the pulling motor receives a signal, the output gear 22 engages with the rack 23, driving the rack 23 downward. As the rack 23 descends, the upper magnet 24 (a permanent magnet built into the magnet holder) at the bottom of the rack 23 attracts the lower magnet 34 (a permanent magnet built into the magnet holder) at the top of the tapping rod 32 due to opposite polarity attraction.

[0052] After the upper magnet 24 moves downward for a period of time, it completes adsorption with the lower magnet 34. Subsequently, under the action of the pulling motor and the output gear 22, the upper magnet 24 and the lower magnet 34 move upward together. During this process, the lower clamping bar of the knocking rod 32 will compress the elastic part 4. The connecting platform 31 and the middle mounting platform 12 are fixed, and the inner diameter of the sliding hole in the center of the connecting platform 31 is larger than the maximum diameter of the knocking rod 32, but smaller than the diameter of the lower magnet 34. Therefore, when the rack 23 and the knocking rod 32 move upward together, the lower clamping platform 322 continues to compress the spring until the final stage, the magnet fixing part of the pulling part passes through the second-stage platform, and the lower magnet 34 is blocked and stops moving. At this time, the elastic part 4 is compressed to the maximum extent by the lower clamping platform 322 of the knocking rod 32, the stored elastic potential energy reaches a peak value, and the downward force exerted on the knocking rod 32 also reaches a maximum. Under the action of the traction motor 21, the upper magnet 24 continues to move upward and separates from the lower magnet 34. Since the attractive force between the upper magnet 24 and the lower magnet 34 is smaller than the elastic force of the elastic member 4 on the lower clamping platform 322, the elastic rod is subjected to a combined force downward and begins to move downward with acceleration.

[0053] As the knocking rod 32 accelerates downward, its overall speed continues to increase, and its kinetic energy gradually increases. At the same time, the compression length of the elastic member 4 gradually decreases. According to Hooke's law, the downward force of the elastic member 4 on the knocking rod 32 tube gradually decreases until the elastic force is zero. After that, the knocking rod 32 continues to move downward for a short displacement and begins to compress the elastic limit member 7. In the process of compressing the elastic limit member 7, the elastic force of the elastic limit member 7 on the knocking rod 32 tube gradually increases until the resultant force on the knocking rod 32 at a certain position is zero, at which time its kinetic energy reaches its maximum value. Subsequently, the knocking rod 32 continues to descend, and part of the kinetic energy is converted into the elastic potential energy of the elastic limit member 7. Finally, the knocking rod 32 drives the knocking hammer 33 to knock on the meat sample to achieve the purpose of knocking.

[0054] After the strike is completed, most of the kinetic energy of the striking rod 32 is instantly transferred to the meat sample. Reaction force from the meat sample causes the striking rod 32 to move upward a short distance before moving downward due to its own gravity, again compressing the elastic member 4. At this point, the striking rod 32 has minimal energy. By the time the rubber hammer reaches the meat sample, all of the energy has been transferred to the elastic stopper 7, converting it into elastic potential energy, thus completing the single strike.

[0055] In this embodiment, the pre-compression amount of the elastic member 4 is controlled by the adjustment knob 63 , and the elastic potential energy of the elastic member 4 is converted into the kinetic energy of the knocking rod 32 .

[0056] Elastic potential energy E p Determined by Hooke's law:

[0057] k: spring constant; x: Spring precompression.

[0058] Assume that the elastic potential energy is completely converted into the kinetic energy of the striking rod 32 (neglecting friction loss):

[0059] m: mass of the striking rod 32; v: instantaneous velocity of the striking rod 32.

[0060] k and x are set by adjusting knob 63; The specific physical process of converting spring elastic potential energy into striking kinetic energy is as follows: 1. Energy storage stage Spring compression: The rack 23 is driven upward by the motor, compressing the elastic member 4 (pre-compression amount x); Potential energy accumulation: elastic potential energy E stored in the elastic member 4 during compression p .

[0061] 2. Energy release stage Magnetic separation: When the rack 23 separates from the knock rod 32, the elastic member 4 begins to recover its deformation; Kinetic energy conversion: The elastic potential energy released by the elastic member 4 is converted into the kinetic energy E of the knocking rod 32 k , driving the knock rod 32 to accelerate downward.

[0062] 3. Tapping effect Impact transmission: The rubber hammer head at the bottom end of the knocking rod 32 hits the surface of the meat sample at a speed v, and the momentum p is transferred to the meat sample, generating an instantaneous knocking force F. The instantaneous knocking force F is affected by the initial expansion and contraction of the elastic member 4. When the initial expansion and contraction strength of the elastic member 4 remains unchanged, the instantaneous knocking force F is a constant value.

[0063] Energy dissipation: Part of the kinetic energy is dissipated through the vibration of the meat sample (source of the detection signal), and the remaining energy is absorbed by the elastic limiter 7.

[0064] Based on the same inventive concept, the present application also provides a method for detecting the freshness of meat, which is implemented based on a knocking device for detecting the freshness of meat based on the knocking method as in any of the above embodiments, and includes the following steps: S1: Start the traction part 2 to move the traction end downward until the upper magnet 24 and the lower magnet 34 are adsorbed and connected; S2: The traction end rises, driving the knocking rod 32 to rise; S3: The knocking rod 32 continues to rise, and after the lower magnet 34 abuts against the lower part of the top mounting platform 11, the traction end continues to rise, the upper magnet 24 and the lower magnet 34 separate, and the knocking rod 32 accelerates downward under the action of the elastic part 4, and the knocking end contacts the meat sample; S4: The traction end continues to rise, and the vibration frequency f of the meat sample is obtained by using the detection component, and the attenuation time is obtained. ; S5: Using decay time And the vibration frequency f is used to calculate the sample freshness score using the formula:

[0065] If the score is <70, the meat sample is considered spoiled; If the score is ≥70, the meat sample is judged.

[0066] It should be noted that the vibration frequency f is affected by the hardness of the meat sample.

[0067] It should be noted that the acceleration sensor 8 is fixed on the meat sample. The bottom of the acceleration sensor 8 adopts a stainless steel self-tapping threaded needle with a screw-in torque of 20 N·m to ensure close contact with the tissue of the meat sample.

[0068] It should be noted that the freshness score is affected by the type of meat and the decay time of the meat. The decay time of the meat has a greater impact on the freshness than the type of meat. In this embodiment, 0.6, 0.4, and 150 are selected to correct and compensate the calculation results so that the measured data falls within the range of 0-100, which makes it easier for measurement personnel to analyze the numerical values ​​intuitively and clearly, thereby increasing convenience.

[0069] As an option for other embodiments, 150 can be replaced with 140 or 160, and the decay time can be adjusted accordingly. and the coefficient of the vibration frequency f, such as

[0070] As long as the calculation results fall stably within the preset numerical range, it will be convenient for calculation and freshness scoring.

[0071] The meat freshness detection method provided by the present embodiment does not require significant damage to the meat sample compared with the prior art. The traction part 2 is used to drive the upper magnet 24 to move up and down. The upper magnet 24 and the lower magnet 34 are attracted to each other, so that the knocking rod 32 moves up and down with the traction end. The knocking rod 32 compresses the elastic part 4, and the limiting part limits the lower magnet 34. The upper magnet 24 and the lower magnet 34 are separated, and the elastic part 4 recovers and drives the knocking rod 32 to move downward to realize the knocking operation. The upper magnet 24 and the lower magnet 34 are cleverly used to realize the automatic separation or connection of the knocking rod 32 and the traction end, without the need for manual connection by employees, thereby improving the use efficiency; the upper magnet 24 and the lower magnet 34 drive the knocking rod 32 to move, giving power to the elastic part 4, and the elastic part 4 drives the knocking rod 32 to move downward, and the rebound force of the knocking rod 32 will not be transmitted The traction member 2 is not affected by the reaction force, which reduces the use loss and extends the service life of the traction member 2; it will not significantly damage the structure of the meat sample, and repeated tests can be carried out at the same position of the meat sample, which can improve the detection accuracy; the attenuation time and vibration frequency of the meat sample vibration are used to calculate the freshness of the meat sample, without destroying the sample, reducing cost waste; through overall position adjustment, the meat sample is knocked at various positions to ensure the high reliability of the data obtained, and the meat sample is knocked in all aspects to improve the detection accuracy; the knocking rod 32 drives the knocking hammer 33 to knock the meat sample downward, which can quickly obtain the vibration frequency and attenuation time of the meat sample, shorten the acquisition time, and improve the detection efficiency.

[0072] The following are two groups of specific embodiments: Example 1: Freshness detection of pork 1. Example Background This implementation example demonstrates the need for rapid detection of pork freshness in a food processing plant in an actual production environment.

[0073] 2. Instance composition Test objects: Pork hind leg meat samples (weighing about 500g, thickness about 5cm), the samples were divided into two groups: one group was fresh pork (within 24 hours after slaughter), and the other group was pork stored for 3 days.

[0074] Detection equipment: the knocking device described in the present invention.

[0075] Auxiliary equipment: temperature control table (for sample temperature balance), data acquisition card (NI USB-6001), computer (for data processing and analysis).

[0076] 3. Detection Steps Step 1: Sample pretreatment Place the pork hind leg sample on a temperature-controlled table and let it stand for 3 minutes to allow the surface temperature of the sample to balance to room temperature (about 25°C).

[0077] Use a laser locator to mark the detection point and ensure that the tapping point is at the same level as the accelerometer.

[0078] Step 2: Device Calibration The laser positioner was used to adjust the light spot position to ensure that the light spot was located at the center of the knocking point on the sample surface.

[0079] Turn the adjustment knob to set the knocking force to medium strength (spring pre-compression is 5mm, knocking force is about 2N).

[0080] Step 3: Data Collection The tapping device is activated and automatically performs a single tap. During the tapping process, the accelerometer simultaneously collects vibration signals at a sampling rate of 20kHz.

[0081] Repeat the above steps and perform 5 taps on each sample to ensure the repeatability and reliability of the data.

[0082] Step 4: Data Processing The collected vibration signal is de-noised using a wavelet denoising algorithm to remove ambient noise. FFT spectrum analysis is performed on the de-noised signal to extract key characteristic parameters (such as vibration frequency and decay time τ). Based on decay time τ and vibration frequency, combined with a pre-set freshness determination model, the pork freshness index is calculated.

[0083] Step 5: Result determination The average decay time τ for fresh pork samples was 15ms, the vibration frequency was 120Hz, and the freshness index was 95 (out of 100). The average decay time τ for pork samples stored for three days was 25ms, the vibration frequency was 80Hz, and the freshness index was 65. Based on the preset threshold (freshness index ≥80 for fresh, <80 for not fresh), the first group of samples was judged as fresh, and the second group as not fresh.

[0084] Example 2: 1. Example Background This example demonstrates the application of the percussion device in the freshness detection of beef and chicken. 2. Instance composition Test objects: Beef samples (weighing approximately 600g, thickness approximately 6cm) and chicken samples (weighing approximately 300g, thickness approximately 3cm). The samples were divided into a fresh group (within 24 hours after slaughter) and a non-fresh group (stored for 3 days). Detection equipment: the knocking device described in the present invention. Auxiliary equipment: temperature control table, data acquisition card (NI USB-6001), computer. 3. Detection Steps Sample pretreatment: Place the beef and chicken samples on a temperature-controlled table and let them stand for 3 minutes to allow their temperature to equalize to room temperature (approximately 25°C). Calibrate the device: Use the laser locator to adjust the spot position to ensure that the tapping point is aligned with the accelerometer. Turn the adjustment knob to set the tapping force to 3N for beef and 1.5N for chicken. Data acquisition: Start the tapping device, tap each sample 5 times, and collect vibration signals simultaneously.

[0085] Data processing: Use wavelet noise reduction, FFT spectrum analysis and other methods to extract the decay time τ and frequency characteristics of the vibration signal. Result determination: Based on the optimized freshness determination model, the freshness index of beef and chicken is calculated.

[0086] 4. Effects Beef test results: The average decay time τ of fresh beef is 12ms, the frequency is 100Hz, and the freshness index is 92; the average decay time τ of stale beef is 20ms, the frequency is 70Hz, and the freshness index is 60. Chicken test results: The average decay time τ of fresh chicken is 18ms, the frequency is 150Hz, and the freshness index is 90; the average decay time τ of stale chicken is 30ms, the frequency is 100Hz, and the freshness index is 55.

[0087] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A percussion device for detecting the freshness of meat based on the percussion method, characterized in that: include: A support frame having a top mounting platform and a middle mounting platform spaced apart from top to bottom; A knocking assembly includes a knocking rod, the knocking rod is slidably matched with the middle mounting platform, the bottom end of the knocking rod forms a knocking end, and the top of the knocking rod is provided with a lower magnet; The upper magnet can absorb and drive the lower magnet to rise, so as to make the knocking rod rise; The lower portion of the top mounting platform can abut against the lower magnet to limit the upward displacement of the lower magnet, so as to separate the lower magnet from the upper magnet; A traction member is provided on the upper side of the top mounting platform, wherein the bottom end of the traction member forms a traction end that can be raised and lowered, and the traction end is provided with an upper magnet, wherein the magnetic poles of the upper magnet and the lower magnet are opposite; a detection component for obtaining the vibration frequency and decay time of the meat sample; as well as The elastic member is arranged between the outer periphery of the knocking rod and the middle mounting platform and is configured with a pre-tightening force for pushing the knocking rod to descend.

2. The percussion device for detecting meat freshness based on the percussion method according to claim 1, characterized in that: An upper clamping platform is provided at the upper part of the knocking rod, and a lower clamping platform is provided at the lower part of the knocking rod. The elastic member is provided between the middle mounting platform and the lower clamping platform. The bottom of the elastic member abuts against the lower clamping platform, and the top of the elastic member abuts against the middle mounting platform. The lower magnet is installed on the upper clamping platform.

3. The percussion device for detecting meat freshness based on the percussion method according to claim 2, characterized in that: A limiting plate is provided on the top mounting platform, the lower side of the limiting plate can abut against the lower magnet, and an avoidance channel is formed in the middle of the limiting plate, and the traction end slides through the avoidance channel.

4. The percussion device for detecting meat freshness based on the percussion method according to claim 1, characterized in that: The traction member comprises: a traction motor, disposed on the top mounting platform and having a transversely extending output shaft; an output gear coaxially fixed to the output shaft; and The rack is vertically arranged and meshes with the output gear. A limiting hole for the output gear to slide through is opened on the top mounting platform, and the bottom end of the rack forms the traction end.

5. The percussion device for detecting meat freshness based on the percussion method according to claim 1, characterized in that: The detection component includes an acceleration sensor, which is placed on the meat sample and is used to detect the vibration frequency and decay time of the meat sample.

6. The percussion device for detecting meat freshness based on the percussion method according to claim 1, characterized in that: The knocking assembly also includes a connecting platform and a knocking hammer. The connecting platform is fixed on the middle mounting platform. The middle part of the connecting platform has a sliding hole that passes through the upper and lower parts. The knocking rod slides through the sliding hole. The knocking hammer is arranged at the bottom of the knocking rod and forms the knocking end.

7. The percussion device for detecting meat freshness based on the percussion method according to claim 1, characterized in that: An articulated arm is provided on the outer side of the middle mounting platform, and the articulated axis is parallel to the horizontal direction. A laser locator is installed on the free end of the articulated arm, and the laser locator is used to calibrate the falling position of the knocking rod.

8. The percussion device for detecting meat freshness based on the percussion method according to claim 1, characterized in that: The elastic member is a spring sleeved on the outer periphery of the knocking rod. The knocking device for detecting the freshness of meat based on the knocking method also includes an adjustment component, which includes: an adjusting driving member, mounted on the bottom of the top mounting platform, wherein the bottom end of the adjusting driving member forms a rotatable output end, and the rotation axis is parallel to the vertical direction; A rotating support is mounted on the middle mounting platform, wherein a lifting channel is formed in the middle of the rotating support for the striking rod to move up and down; an adjusting knob, sleeved on the outer periphery of the rotating support and threadedly connected to the rotating support, an adjusting groove being provided inside the adjusting knob corresponding to the lifting channel, and an inner wall of the adjusting groove being connected to the top end of the elastic member; and The belt is simultaneously sleeved on the outer periphery of the adjusting knob and the output end of the adjusting drive member to achieve synchronous movement of the adjusting knob and the output end of the adjusting drive member.

9. The percussion device for detecting meat freshness based on the percussion method according to claim 2, characterized in that: A limit plate is provided at the bottom of the support frame, and a limit hole is provided on the limit plate for the knocking rod to slide up and down. An elastic limit piece and a limit ring are provided between the limit plate and the lower clamping platform. The elastic limit piece is sleeved on the outer circumference of the knocking rod, and the bottom end of the limit ring can abut against the limit plate up and down.

10. A method for detecting meat freshness, implemented based on the percussion device for detecting meat freshness based on the percussion method according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Start the traction part and move the traction end downward until the upper magnet and the lower magnet are attracted and connected; S2: The traction end rises, driving the knocking rod to rise; S3: The knocking rod continues to rise. After the lower magnet contacts the lower part of the top mounting platform, the pulling end continues to rise. The upper and lower magnets separate. The knocking rod accelerates downward under the action of the elastic member, and the knocking end contacts the meat sample. S4: Use the detection component to obtain the vibration frequency f of the meat sample and obtain the decay time : S5: Using decay time And the vibration frequency f are used to calculate the sample freshness score using the formula: If the score is <70, the meat sample is considered spoiled; If the score is ≥70, the meat sample is judged.

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