Ietalurus punetaus gill cover edge detection mechanism and detection method

Abstract

The invention relates to a channel catfish gill cover edge detection mechanism and method. The channel catfish gill cover edge detection mechanism comprises a fish body clamp; the probe assembly is provided with a lead screw module controlled by the electric control system, and the probe assembly is driven by the lead screw module to integrally move, make contact with a fish body and detect the fish body; wherein the probe assembly comprises a plurality of probes and a spring box base, each probe is provided with a pinhole sliding block, a probe spring and a pressure sensor, the pinhole sliding block is in sliding fit with the spring box base in the detection direction, the pressure sensor is fixedly connected with the spring box base, and the front end and the rear end of the probe spring are connected with the pinhole sliding block and the pressure sensor respectively. According to the probe assembly provided by the invention, the probes are connected with the springs through the special pinhole sliding blocks, and the identification and positioning of the gill cover edge of the channel catfish can be completed under the conditions that the detection width is 3-5mm and the detection precision is 1-1.5 mm through the adjustment and combination of the number, the diameter and the distance of the probes, so that the problem of bloodletting point positioning of bloodletting equipment is solved.

Description

Technical Field

[0001] This invention relates to the field of fish processing technology, specifically to a detection mechanism and method for the gill cover edge of the spotted catfish. Background Technology

[0002] In the initial processing of channel catfish, bleeding is typically achieved by severing the gill arteries. Currently, this is done manually by making an incision at the edge of the gill cover to puncture the gill vessels. However, no fish processing equipment for bleeding at the gill cover is currently available, either domestically or internationally. To automate this process, identifying and locating the bleeding point at the gills is the primary challenge. The gill cover area has a complex structure, consisting of the gill cover, the gill membrane, and multiple branched gill ribs that support its expansion. The end of the gill membrane is also covered by a cleithrum. Furthermore, the outer surface of the gill membrane varies in color, making it impossible to accurately locate the puncture point using machine vision.

[0003] Regarding fish identification, existing technologies utilize advanced machine learning and deep learning algorithms, combined with image processing and computer vision techniques, to classify fish and identify fish diseases for use in fisheries management. However, fish identification encompasses the characteristic parameters of the entire fish, without focusing on specific gill features. Furthermore, existing technologies do not disclose devices for locating the gill cover edge using mechanical structures. Summary of the Invention

[0004] The purpose of this invention is to provide a detection mechanism and method for the gill cover edge of the spotted catfish, so as to solve the problems existing in the prior art.

[0005] The objective of this invention is achieved as follows: a gill cover edge detection mechanism for the spotted catfish, comprising:

[0006] The fish clamp is installed at the inspection station and is used to hold the fish.

[0007] The probe assembly is equipped with a lead screw module controlled by an electronic control system. The probe assembly moves as a whole under the drive of the lead screw module to contact and detect the fish body.

[0008] The probe assembly includes several probes arranged side by side that contact the fish body, and a spring box base connected to the lead screw module for transmission. Each probe is equipped with a pinhole slider, a probe spring, and a pressure sensor connected to the electrical signal of the electronic control system. The pinhole slider slides along the detection direction with the spring box base. The pressure sensor is fixedly connected to the spring box base and is located behind the pinhole slider. The front and rear ends of the probe spring are respectively connected to the pinhole slider and the pressure sensor.

[0009] Furthermore, the probe assembly also includes a mating plate, which is fixedly connected to the spring box base. The mating plate has several through guide holes, through which the probes move and pass. The mating plate is positioned in front of the pinhole slider.

[0010] Furthermore, the fish clamp includes:

[0011] Base;

[0012] A clamping component for supporting and holding the side wings of the fish's body; the base supports and fixes the clamping component.

[0013] A head-fixing sleeve used to support and define the position of the fish's head, which is fixedly connected to the base;

[0014] Tail limiting component used to support and limit the tail of a fish, and its fixed connection base.

[0015] Furthermore, the fish clamp also includes a height adjustment plate facing the probe, the probe being perpendicular to the height adjustment plate, the height adjustment plate being adjustablely connected to the clamping component, and the height adjustment plate having a limiting strip hole for defining the left and right working positions of the probe, the probe being movably fitted through the limiting strip hole.

[0016] Furthermore, the clamping component includes a clamping block and a clamping baffle arranged opposite to each other. The clamping baffle is elastically rotatably connected to the clamping block. The clamping baffle is equipped with a pin and a torsion spring assembly. The pin serves as the rotation support shaft of the clamping baffle, and the torsion spring assembly drives the clamping baffle to clamp the fish body.

[0017] Furthermore, the clamping surface of the clamping baffle is designed as a concave arc surface, which matches the surface of the fish body.

[0018] Furthermore, the clamping surface of the clamping block is provided with a toothed groove extending along the length of the fish body, the toothed groove being used to prevent the fish body from moving upwards.

[0019] Furthermore, the head fixing sleeve has a bottom surface that matches the shape of the fish's head and a C-shaped limiting side surface, and the bottom surface of the head fixing sleeve is set as an arc-shaped surface that supports the fish's head.

[0020] Furthermore, the lead screw module includes:

[0021] Main slider seat;

[0022] A sliding seat that supports and securely connects to the spring box base;

[0023] A servo motor and a lead screw are provided. The servo motor is fixedly connected to the main slider seat. One end of the lead screw is fixedly connected to the output spindle of the servo motor, and the other end of the lead screw is rotatably connected to the main slider seat. The lead screw passes through the slider seat and is threadedly engaged with the slider seat.

[0024] As another aspect of the present invention, a detection method is proposed, comprising the following steps:

[0025] Step 1: Use the lead screw module to drive the spring box base to move a certain distance in a direction perpendicular to the fish body. Pre-install a single probe and contact the fish body at the gill cover, gill rib gap and cleithrum respectively. Record the pressure output by the pressure sensor as Fa, Ft and Fo respectively.

[0026] The second step, before the formal testing, is to use a fish clamp to fix the position of the fish, and then install the probe assembly and lead screw module on one side of the fish. The height of the fish is fixed, but it can move horizontally within the range near the edge of the gill cover.

[0027] Step 3: During testing, move the probe near the edge of the fish's gill cover and record its relative horizontal coordinates. Use the lead screw module to drive the spring box base and probe assembly to move a certain distance perpendicular to the fish's body, so that the probe contacts the gill cover area. At this time, the probe spring corresponding to the probe is compressed according to the corresponding puncture position. Defined from the fish head to the tail, the pressure sensors of the corresponding probes output pressures, recorded as F1, F2, and F3 respectively. Filter the pressure difference values ​​of F1, F2, and F3. If the pressure difference value is less than 2N, it is considered as equal pressure; otherwise, it is distinguished by magnitude. The gill cover edge detection results are determined according to the following method:

[0028] A. When Fo≈F3>F1>F2≈Ft, the probe is located at the edge of the gill cover.

[0029] B. When Fo≈F2=F3>F1, the probe is located at the edge of the gill cover.

[0030] C. When F1 = F2 > F3, the probe is located at the edge of the gill cover.

[0031] Except for the AC case mentioned above, edges are considered not detected.

[0032] The beneficial effects of this invention are as follows:

[0033] 1. This invention can solve the problem of difficulty in locating the bleeding point during the gill bleeding process of spotted catfish using mechanical equipment. Since the bleeding point of the catfish gill is located between the gill ray bone and the cleithrum bone, the positioning accuracy is at the millimeter level. Machine vision cannot achieve accurate positioning with millimeter precision. Therefore, the cover edge detection mechanism and judgment method proposed in this invention are needed for judgment.

[0034] 2. The spotted catfish has a flat head (widest horizontally), a transitional middle section, and a high tail (widest vertically). Conventional clamping mechanisms that use the middle section of the body cannot achieve secure positioning. This invention achieves secure positioning of this species of fish by using a method of horizontal clamping at the head, weight-bearing at the middle of the body, and vertical clamping at the tail.

[0035] 3. The probe assembly proposed in this invention connects the probe to the spring through a specially designed pinhole slider. By adjusting the number, diameter, and spacing of the probes, it can identify and locate the edge of the gill cover of the spotted catfish with a detection width of 3-5 mm and a detection accuracy of 1-1.5 mm, thus solving the problem of bloodletting point positioning in bloodletting equipment. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the main layout of the present invention.

[0037] Figure 2 This is a schematic diagram of a fish clamp.

[0038] Figure 3 This is a schematic diagram of the head fixing sleeve.

[0039] Figure 4 This is a schematic diagram of the structure of the body side wing clamping component.

[0040] Figure 5 This is a schematic diagram of the clamping block.

[0041] Figure 6 This is a schematic diagram of the height adjustment plate installation scheme.

[0042] Figure 7 This is a three-dimensional schematic diagram of the probe assembly.

[0043] Figure 8 This is a schematic diagram of the lead screw module.

[0044] Figure 9 This is a schematic diagram showing the relative relationship between the probe and the mating plate.

[0045] Figure 10 This is a schematic diagram of the probe head.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1-Lead screw module, 101-Servo motor, 102-Main slider seat, 103-Lead screw, 104-Sliding seat;

[0048] 2-Probe assembly, 201-Probe, 202-Spring box base, 203-Pinhole slider, 204-Probe spring, 205-Pressure sensor, 206-Matching plate;

[0049] 3-Fish body clamp, 301-Head fixing sleeve, 301a-Arc-shaped surface, 302-Clamping component, 302a-Clamping block, 302b-Clamping baffle, 302c-Torsion spring assembly, 302d-Pin, 302e-Gear groove, 303-Tail limiting component, 304-Base, 305-Height adjustment plate, 305a-Limiting strip hole;

[0050] 4-Fish body. Detailed Implementation

[0051] The following will refer to the appendices in the embodiments of the present invention. Figure 1-10 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0052] like Figure 1 As shown, a gill cover edge detection mechanism for the spotted catfish is proposed, comprising:

[0053] Electrical control systems typically use PLC controllers;

[0054] The fish clamp 3, installed at the inspection station, is used to firmly hold the fish 4, providing a stable support platform for the inspection operation.

[0055] The probe assembly 2 is equipped with a lead screw module 1 controlled by an electronic control system. The probe assembly 2 moves as a whole under the drive of the lead screw module 1 to contact and detect the fish body 4.

[0056] Among them, such as Figure 7 As shown, the probe assembly 2 includes three probes 201 arranged side by side that contact the fish body 4, and a spring box base 202 that is connected to the lead screw module 1 for transmission. Each probe 201 is equipped with a pinhole slider 203, a probe spring 204, and a pressure sensor 205 that is connected to the electrical signal of the electronic control system. The pinhole slider 203 slides in cooperation with the spring box base 202 along the detection direction (the bottom of the pinhole slider 203 is provided with a T-shaped protrusion, and the spring box base 202 is provided with a T-shaped groove, and the T-shaped protrusion and the T-shaped groove are connected). The pressure sensor 205 is fixedly connected to the spring box base 202 and is located behind the pinhole slider 203. The front and rear ends of the probe spring 204 are respectively connected to the pinhole slider 203 and the pressure sensor 205. The probe spring 204 is partially nested in the spring box base 202.

[0057] like Figure 9As shown, the probe assembly 2 also includes a mating plate 206, which is fixedly connected to the spring box base 202. The mating plate 206 has several through guide holes, through which the probes 201 move and pass. The mating plate 206 is located in front of the pinhole slider 203.

[0058] The pinhole slider 203 guides the probe 201 to achieve telescopic displacement in a straight direction, and can be restored to its initial state by the probe spring 204; the probe assembly 2 has three probes 201 (the number can be unlimited here), arranged in parallel, and the mating plate 206 has three sets of 90° V-shaped grooves with a groove depth of 1.02mm and a groove spacing of 2mm, forming three guide holes that move and cooperate with the probes 201, which can ensure that the spacing of each probe 201 is consistent, thereby achieving high-precision positioning and detection functions; in this embodiment, the structural configuration of the mating plate 206 is relatively special, which not only improves the positioning accuracy of the probe assembly 2, but also enhances its stability and reliability in complex environments, and is one of the key components for achieving high-precision detection.

[0059] like Figure 10 As shown, probe 201 has a diameter of 1 mm, a tip with an inverted W-shaped toothed tip, a tooth cutting angle of 65°, a tooth radius of 200 mm, a length of 82 mm, and a tooth spacing of 2 mm. Probe 201 is made of high-strength stainless steel, possessing excellent corrosion resistance and mechanical strength. This design achieves a detection accuracy of 1-2 mm and is suitable for detection tasks within a small distance range of 3-5 mm. It is particularly suitable for detecting pressure distribution characteristics during the processing of flexible objects such as fish bodies, providing reliable hardware support for accurately locating the edge of the gill cover.

[0060] The technical parameters of probe spring 204 are as follows:

[0061] Initial pressure F1 = 12N, maximum compression 20mm, pressure at maximum compression F2 = 1.5F1.

[0062] like Figure 2-6 As shown, the fish clamp 3 includes:

[0063] Base 304;

[0064] The clamping component 302 is used to support and hold the side wings of the fish's body, and the base 304 supports and fixes the clamping component 302.

[0065] A head-fixing sleeve 301 is used to support and define the position of the fish's head, and is fixedly connected to a base 304.

[0066] Tail limiting component 303, used to support and limit the tail of the fish, is fixedly connected to base 304. It is U-shaped and has a U-shaped groove. When positioning, the fish tail is placed in the U-shaped groove, limiting the position of the two sides of the fish tail. The tail limiting component 303 is 120mm long and 90mm high, with a distance of 30mm between the two side walls. It can effectively prevent the fish tail of the spotted catfish from being thrown out of the clamp when it moves upward. This not only enhances the overall stability of the fish clamp, but also further improves the safety and reliability of the detection process.

[0067] The height adjustment plate 305 is directly opposite the probe 201, such as Figure 6 As shown, the probe 201 is perpendicular to the height adjustment plate 305. The height adjustment plate 305 is vertically and adjustablely connected to the clamping component 302. The height adjustment plate 305 has a limiting strip hole 305a for limiting the left and right working positions of the probe 201. The probe 201 moves through the limiting strip hole 305a.

[0068] Among them, such as Figure 4 As shown, the clamping component 302 includes a clamping block 302a and a clamping baffle 302b arranged opposite to each other. The clamping baffle 302b is elastically rotatably connected to the clamping block 302a. The clamping baffle 302b is equipped with a pin 302d and a torsion spring assembly 302c. The pin 302d serves as the rotation support shaft of the clamping baffle 302b. The torsion spring assembly 302c drives the clamping baffle 302b to clamp the fish body 4, so that the clamping block 302a and the clamping baffle 302b clamp the fish body relative to each other. The torsion spring assembly 302c is equipped with 6 torsion springs, which are made of stainless steel with a wire diameter of 2.5mm, 3 turns, and a pin angle of 120°. Within the clamping range, the force of a single spring is about 7.97N, which provides sufficient clamping force for clamping the fish body and ensures that the fish body remains stable during the inspection process.

[0069] In a preferred embodiment, the height adjustment plate 305 is fixedly connected to the clamping block 302a via a groove, bolts, etc., and can move horizontally within a range near the edge of the fish's gill cover. This design facilitates precise positioning of the detection mechanism, allowing the probe assembly 2 to be flexibly adjusted according to the specific position of the fish 4, further improving the accuracy and reliability of the detection.

[0070] The clamping baffle 302b adopts a contour-following design: the clamping surface of the clamping baffle 302b is set as a concave arc surface and matches the surface of the fish body 4, so that the clamping baffle 302b can tightly hold the fish body 4 and ensure that the fish body will not be displaced during the testing process.

[0071] like Figure 5As shown, the clamping surface of the clamping block 302a is provided with a toothed groove 302e extending along the length of the fish body 4. The toothed groove 302e is used to prevent the fish body 4 from moving upward. The distance between adjacent toothed grooves 302e is 5mm, the width of a single toothed groove 302e is 3mm, and it is inclined at 45° on one side.

[0072] like Figure 3 As shown, the head fixing sleeve 301 has a bottom surface and a C-shaped limiting side surface that are adapted to the shape of the fish head 4, so as to limit the position of the head, side and bottom of the fish head. The bottom surface of the head fixing sleeve 301 is set as an arc surface 301a to support the fish head. The sleeve is inclined at 22° for a 50mm length from the fish mouth to the body in the bottom area of ​​the fish head, with an arc radius of R88.5mm. This contoured arc design can firmly frame the fish head inside the head fixing sleeve 301. This design not only improves the stability of the fish body clamping, but also reduces damage to the fish body 4, ensuring that the fish body 4 remains stationary during the detection process, providing a basic guarantee for high-precision detection.

[0073] The technical specifications of the fish clamp 3 are as follows: The head fixing sleeve 301, the clamping component 302, and the tail limiting component 303 are securely connected by high-strength bolts to ensure the coordination and stability of each component during operation. The design of the fish clamp 3 fully considers the special shape of the spotted catfish. By clamping the head horizontally, bearing the weight in the middle of the body, and clamping the tail vertically, the fish body 4 is firmly fixed, providing stable support for subsequent inspection operations.

[0074] As a preferred embodiment, such as Figure 8 As shown, the aforementioned lead screw module 1 includes:

[0075] Main slider seat 102;

[0076] The sliding seat 104 supports and is fixedly connected to the spring box base 202;

[0077] The servo motor 101 and the lead screw 103 are fixedly connected to the main slider seat 102 and controlled by the electronic control system. One end of the lead screw 103 is fixedly connected to the output spindle of the servo motor 101, and the other end of the lead screw 103 is rotatably connected to the main slider seat 102. The lead screw 103 passes through the sliding seat 104 and is threadedly engaged with the sliding seat 104.

[0078] Under the control of the electronic control system, the servo motor 101 drives the lead screw 103 to rotate, which in turn drives the sliding seat 104 and the probe assembly 2 to move back and forth along a preset trajectory, thereby providing a basic guarantee for the operation of the entire positioning mechanism.

[0079] It should be noted that the skeletal structure at the gill cover of a fish, from the head towards the body, consists of the gill cover, gill ray bones (with gaps), and cleithrum.

[0080] Based on the above-mentioned methods, a method for detecting the gill cover edge of the spotted catfish is proposed, as follows:

[0081] Step 1: Use the lead screw module 1 to drive the spring box base 202 to move a certain distance in a direction perpendicular to the fish body 4. Pre-install a single probe 201 and contact the fish body gill cover, gill rib gap and cleithrum respectively. Record the pressure output by the pressure sensor 205, which are denoted as Fa, Ft and Fo respectively.

[0082] The second step, before the formal testing, is to fix the position of the fish body 4 using the fish body clamp 3, and install the probe assembly 2 and the lead screw module 1 on one side of the fish body 4. Their height position is fixed, and they can move in the horizontal direction within the range near the edge of the fish body gill cover.

[0083] Third step: During detection, move probe 201 to the vicinity of the edge of the fish's gill cover (manual judgment or machine vision judgment). Record the relative horizontal coordinates of probe 201. Use the lead screw module 1 to drive the spring box base 202 and probe assembly 2 to move a certain distance (equal to the preset value) in a direction perpendicular to the fish body 4, so that probe 201 contacts the gill cover area of ​​the fish body 4. At this time, the probe spring 204 corresponding to probe 201 is compressed according to the corresponding puncture position. Defined from the fish head to the fish tail, the pressure sensor 205 corresponding to probe 201 outputs pressures respectively, recorded as F1, F2, and F3. Filter the pressure difference values ​​of F1, F2, and F3. If the pressure difference value is less than 2N, it is considered as equal pressure; otherwise, it is distinguished by magnitude. Determine the gill cover edge detection result according to the following method:

[0084] A. When Fo≈F3>F1>F2≈Ft, the coordinates of probe 201 are at the edge of the gill cover.

[0085] B. When Fo≈F2=F3>F1, the coordinates of probe 201 are at the edge of the gill cover;

[0086] C. When F1 = F2 > F3, the coordinates of probe 201 are at the edge of the gill cover;

[0087] Except for the AC case mentioned above, edges are considered not detected.

[0088] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In this invention, it should also be noted that the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, an integrally formed connection, a mechanical connection, or an indirect connection through intermediate connecting parts. The specific meaning of the terms in this utility model can be understood according to the specific circumstances.

[0089] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0090] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A mechanism for detecting the edge of the gill cover of a spotted catfish, characterized in that, include: The fish body clamp (3) is set at the inspection station and is used to clamp the fish body (4); The probe assembly (2) is equipped with a lead screw module (1) controlled by an electronic control system. The probe assembly (2) moves as a whole under the drive of the lead screw module (1) to contact and detect the fish body (4). The probe assembly (2) includes several probes (201) arranged side by side that are in contact with the fish body (4), and a spring box base (202) that is connected to the lead screw module (1) for transmission. Each probe (201) is equipped with a pinhole slider (203), a probe spring (204), and a pressure sensor (205) that is connected to the electrical signal of the electronic control system. The pinhole slider (203) slides in cooperation with the spring box base (202) along the detection direction. The pressure sensor (205) is fixedly connected to the spring box base (202) and is located behind the pinhole slider (203). The front and rear ends of the probe spring (204) are respectively connected to the pinhole slider (203) and the pressure sensor (205).

2. The gill cover edge detection mechanism for spotted catfish according to claim 1, characterized in that, The probe assembly (2) also includes a mating plate (206), which is fixedly connected to the spring box base (202). The mating plate (206) has several through guide holes. The probe (201) moves through the guide holes of the mating plate (206) one by one. The mating plate (206) is located in front of the pinhole slider (203).

3. The gill cover edge detection mechanism for spotted catfish according to claim 1, characterized in that, The fish clamp (3) includes: Base (304); A clamping component (302) for supporting and holding the side wings of the fish body, wherein the base (304) supports and fixes the clamping component (302); A head-fixing sleeve (301) is used to support and define the position of the fish's head, and is fixedly connected to a base (304); Tail limiting component (303) used to support and limit the tail of the fish, and fixedly connected to base (304).

4. The gill cover edge detection mechanism for spotted catfish according to claim 3, characterized in that, The fish clamp (3) also includes a height adjustment plate (305) facing the probe (201). The probe (201) is perpendicular to the height adjustment plate (305). The height adjustment plate (305) is vertically and adjustablely connected to the clamping component (302). The height adjustment plate (305) has a limiting strip hole (305a) for limiting the left and right working positions of the probe (201). The probe (201) moves through the limiting strip hole (305a).

5. The gill cover edge detection mechanism for spotted catfish according to claim 3, characterized in that, The clamping component (302) includes a clamping block (302a) and a clamping baffle (302b) arranged opposite to each other. The clamping baffle (302b) is elastically rotatably connected to the clamping block (302a). The clamping baffle (302b) is equipped with a pin (302d) and a torsion spring assembly (302c). The pin (302d) serves as the rotation support shaft of the clamping baffle (302b). The torsion spring assembly (302c) drives the clamping baffle (302b) to clamp the fish body (4). The clamping surface of the clamping baffle (302b) is a concave arc surface that matches the surface of the fish body (4).

6. The gill cover edge detection mechanism for the spotted catfish according to claim 1, characterized in that, The probe assembly (2) has three probes (201) arranged in parallel. The diameter of the probe (201) is 1 mm, the tip is in the shape of an inverted W, the tooth angle is 65°, and the tooth radius is 200 mm.

7. The gill cover edge detection mechanism for spotted catfish according to claim 5, characterized in that, The clamping surface of the clamping block (302a) is provided with a toothed groove (302e) extending along the length of the fish body (4), and the toothed groove (302e) is used to prevent the fish body (4) from moving upward.

8. The gill cover edge detection mechanism for spotted catfish according to claim 3, characterized in that, The head fixing sleeve (301) has a bottom surface and a C-shaped limiting side surface that are adapted to the head shape of the fish body (4). The bottom surface of the head fixing sleeve (301) is set as an arc-shaped surface (301a) that supports the fish head.

9. A gill cover edge detection mechanism for spotted catfish according to any one of claims 1-8, characterized in that, The lead screw module (1) includes: Main slider seat (102); A sliding seat (104) supports and securely connects to a spring box base (202); A servo motor (101) and a lead screw (103) are provided. The servo motor (101) is fixedly connected to the main slider seat (102). One end of the lead screw (103) is fixedly connected to the output spindle of the servo motor (101). The other end of the lead screw (103) is rotatably connected to the main slider seat (102). The lead screw (103) passes through a sliding seat (104) and is threadedly engaged with the sliding seat (104).

10. A detection method based on the gill cover edge detection mechanism of the spotted catfish as described in claim 3, characterized in that, Includes the following steps: Step 1: Use the lead screw module (1) to drive the spring box base (202) to move a certain distance in a direction perpendicular to the fish body (4). Pre-install a single probe (201) and contact the fish body gill cover, gill rib gap and cleithrum respectively. Record the pressure output by the pressure sensor (205) as Fa, Ft and Fo respectively. The second step, before the formal test, is to use the fish body clamp (3) to fix the position of the fish body (4), and install the probe assembly (2) and the screw module (1) on one side of the fish body (4). The height position is fixed, and it can move in the horizontal direction within the range near the edge of the fish body gill cover. Third step: During the detection, the probe (201) is moved to the vicinity of the edge of the fish's gill cover. The relative horizontal coordinates of the probe (201) are recorded. The lead screw module (1) drives the spring box base (202) and the probe assembly (2) to move a certain distance in a direction perpendicular to the fish body (4), so that the probe (201) contacts the gill cover area of ​​the fish body (4). At this time, the probe spring (204) corresponding to the probe (201) is compressed according to the corresponding puncture position. Defined from the fish head to the fish tail, the pressure sensor (205) corresponding to the probe (201) outputs pressures respectively, which are recorded as F1, F2, and F3. The pressure difference values ​​of F1, F2, and F3 are screened. If the pressure difference value is less than 2N, it is considered as equal pressure. Otherwise, the size is distinguished. The detection results of the gill cover edge are judged according to the following method: A. When Fo≈F3>F1>F2≈Ft, the coordinates of the probe (201) are at the edge of the gill cover; B. When Fo≈F2=F3>F1, the coordinates of probe (201) are at the edge of the gill cover; C. When F1 = F2 > F3, the coordinates of probe (201) are at the edge of the gill cover; Except for the AC case mentioned above, edges are considered not detected.

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