Deep sea farming living fish digital identity identification and binding device

Abstract

The present application belongs to the technical field of acoustic positioning, and provides a deep-sea aquaculture living fish digital identity identification and binding device. The present application comprises a dorsal fin anchoring base, an air cavity and an acoustic cabin arranged in the dorsal fin anchoring base, and the tail of the dorsal fin anchoring base is provided with a bistable collection beam, one end of the bistable collection beam is connected to the dorsal fin anchoring base, and the other end is a free end; the bistable collection beam further comprises a blunt body fixed to the free end of the bistable collection beam for interacting with water flow to generate alternating excitation; the acoustic cabin is internally provided with a transponder chip for emitting an acoustic signal containing fish identity identification. Through passive self-power supply, dorsal fin minimally invasive anchoring, self-adaptive growth and double wake-up signals, the long life cycle digital identity tracking of deep-sea aquaculture fish from release to harvest is realized, and the effective working time is significantly prolonged, and the marking trauma and aquaculture management cost are reduced.

Description

Technical Field

[0001] This invention relates to the field of aquaculture technology and provides a digital identity identification and binding device for live fish cultured in deep-sea areas. Background Technology

[0002] As a crucial component of modern fisheries, deep-sea aquaculture's large-scale and intensive development has created an urgent need for individual identification and digital management of farmed fish throughout their entire lifecycle. Currently, fish identification primarily employs physical tagging, passive integrated transponder (PIT) tagging, and acoustic tagging techniques. Physical tagging involves attaching tags to the fish's dorsal fin or gill covers; while simple to operate, it's prone to detachment and has limited information capacity. PIT tagging involves implanting microchips subcutaneously or into the abdominal cavity of the fish, storing unique identification codes, but its reading distance is short and it relies on specialized readers. Acoustic tagging, on the other hand, uses acoustic signals to achieve long-range identification and location of individual fish, and is currently a vital technology for monitoring deep-sea aquaculture. However, existing acoustic tagging technologies still have the following shortcomings: Most existing acoustic tags rely on battery power, and due to battery capacity limitations, the tag lifespan is typically only 20 days to a year, making it difficult to cover the entire fish farming cycle. Furthermore, once the battery is depleted, it cannot be replaced or replacement is costly. The tag is primarily fixed to the fish via abdominal implantation or external attachment. Abdominal implantation requires surgery, causing significant trauma to the fish and increasing the risk of infection. Existing tags typically use timed transmission or single-signal wake-up modes, resulting in numerous ineffective transmissions and wasted energy. Existing technology US5168473A provides one or more passive transducers for converting sound (including biosound waves from living aquatic animals in the water) into electrical signals, which are then combined with active sonar (echo detection) to form an integrated marine acoustic system. In addition, a universal display can be used in conjunction with satellite (GPS) or Loran locators, allowing fishing vessels carrying the equipment to display their location on electronically reproduced area maps or maps, along with information on fish locations, including fish movement direction and species indication. Summary of the Invention

[0003] This invention achieves long-lifecycle digital identity tracking of deep-sea aquaculture fish from release to harvest through self-powered, dorsal fin minimally invasive anchoring, adaptive growth, and dual wake-up signals. This significantly extends the effective working time and reduces tagging trauma and aquaculture management costs.

[0004] A digital identification and binding device for live fish in deep-sea aquaculture includes a dorsal fin anchoring base and an air cavity and acoustic chamber disposed within the base. The tail of the dorsal fin anchoring base is equipped with a bistable acquisition beam, one end of which is connected to the base, and the other end is a free end. The bistable acquisition beam also includes a blunt body fixed to the free end for interacting with water flow to generate alternating excitation. A transponder chip is located inside the acoustic chamber for emitting acoustic signals containing the fish's identification. The dorsal fin anchoring base includes at least two anchoring pins. The heads of the pins and the base are located on either side of the fish's dorsal fin, connected by a flexible element. The pin heads are located on the dorsal surface of the dorsal fin, and the pin holes are located on the ventral surface. The two are connected by the pin shanks and clamp the dorsal fin from both sides. The key lies in the use of a flexible element, such as medical-grade silicone tape, braided polyester thread, or elastic polymer strip, to connect the heads of the two anchoring pins, forming a U-shaped structure. This flexible element allows the spacing between the two anchoring pin heads to automatically adjust to the fish's growth and changes in dorsal fin morphology. As the fish grows and the fin spacing increases, the flexible element stretches to adapt. The flexible element also serves to prevent detachment: even if one anchoring pin accidentally detaches from the fin membrane, the other anchoring pin remains connected to the detached pin via the flexible element, preventing the entire device from being lost.

[0005] The device employs an external dorsal fin anchoring scheme, fixed to the base of the dorsal fin of the farmed fish via an anchoring base. When the fish is swimming, the water flow impacts a blunt body fixed to the free end of the bistable acquisition beam. Under the unidirectional water flow, the blunt body generates periodic vortices and detaches, creating alternating lift to excite the bistable acquisition beam. Under alternating excitation, the bistable acquisition beam undergoes large-amplitude jump vibrations between its two stable bending equilibrium states. The piezoelectric film attached to the beam surface generates an alternating electrical signal as the beam bends and deforms. This electrical signal is processed by the circuit components (rectification, energy storage, and power management) within the acoustic chamber, providing operating power to the transponder chip. When an external reader (such as an underwater acoustic probe) sends an interrogation signal, the transponder chip is activated, using stored energy to emit an acoustic signal containing the fish's unique identifier. The reader receives and decodes this signal to complete individual identification. An air chamber provides buoyancy compensation for the device, ensuring near-neutral buoyancy in the water and avoiding additional burden on the fish's normal swimming.

[0006] Preferably, the dorsal fin anchoring base includes an anchoring pin for passing through the fin rays of the fish's dorsal fin, the diameter of which is smaller than the spacing between the fin rays. The anchoring pin is the core actuator that establishes a mechanical connection between the device and the fish's dorsal fin. The fish's dorsal fin consists of multiple parallel fin rays and fin membranes between them, with a certain natural spacing between the fin rays. During installation, a micro-hole, slightly smaller in diameter than the fin ray spacing, is formed by piercing the fin membrane at the connective tissue between the fin rays using a medical piercing tool. The anchoring pin is then passed through this micro-hole. After passing through the dorsal fin, the head of the anchoring pin is located on one side of the dorsal fin, and the anchoring base is located on the other side, with the two clamped and fixed together by the shank of the anchoring pin. The diameter of the anchoring pin is designed to be smaller than the natural spacing between the fin rays to ensure that the anchoring pin does not compress or damage the bony tissue of adjacent fin rays when passing through the fin membrane. The anchoring pin penetrates the flexible connective tissue between the fin rays, not the fin rays themselves, therefore it has no substantial impact on the structural integrity and mechanical load-bearing capacity of the dorsal fin. After insertion, the clamping force between the anchor pin head and the dorsal fin anchoring base is maintained by the elastic deformation of the dorsal fin rays and the frictional resistance of the connective tissue, thus achieving a firm fixation of the device.

[0007] Preferably, the bistable acquisition beam is offset at the tail end of the dorsal fin anchoring base on the side close to the dorsal fin of the fish. When the dorsal fin anchoring base is fixed, the centerline of the bistable acquisition beam is located on the extension line of the centerline of the fish's dorsal fin.

[0008] Preferably, the bistable acquisition beam comprises at least two stacked metal sheets, each having two stable bending equilibrium states, and a piezoelectric film is attached to the surface of the metal sheets.

[0009] The bistable acquisition beam employs an offset mounting layout, with its fixed end connected to the tail of the anchor base near the dorsal fin of the fish. This arrangement allows the free end of the beam and its connected blunt body to extend rearward along the dorsal fin's centerline, ensuring the beam's centerline is collinear with the dorsal fin's centerline. When the fish sways left and right, the dorsal fin, as an extension of the fish's longitudinal axis, experiences its largest sway amplitude at the fin's centerline and smallest at its edge. Aligning the acquisition beam's centerline with the dorsal fin's centerline allows the beam to achieve maximum lateral displacement input under the base excitation of the fish's swaying, thereby driving the beam to undergo large-amplitude jump vibrations between the two steady states. Structurally, the beam utilizes at least two stacked metal sheets. During manufacturing, mechanical pre-bending or in-plane displacement constraints pre-deform the sheets, creating two stable bending equilibrium states with opposite curvature directions. A piezoelectric film is tightly bonded to the surface of the metal sheets. When the sheets undergo sudden jump bending between steady states, the piezoelectric film withstands tensile and / or compressive strain, converting mechanical strain energy into electrical energy using the positive piezoelectric effect.

[0010] Preferably, the blunt body is a D-shaped cross-section with its arc surface facing the fish's dorsal fin, and its chord surface facing away from the dorsal fin, perpendicular to the water flow direction. The blunt body uses a D-shaped cross-section, with its arc surface facing the fish's back and its chord surface facing outwards, and the chord surface plane perpendicular to the water flow direction. When water flows over the D-shaped blunt body, the arc surface allows the water to smoothly adhere to the surface of the blunt body and gradually accelerate under the geometric guidance of the arc surface. When the water flows to the sharp edge of the blunt body's trailing edge, due to the abrupt geometric change, the boundary layer undergoes deterministic flow separation at that point, forming alternating vortices downstream of the blunt body. During the vortex shedding process, the blunt body is subjected to a periodic lateral force perpendicular to the water flow direction. This alternating lift drives the bistable acquisition beam to reciprocate across the trap between its two steady states. The design of using a D-shaped blunt body with its arc surface facing the dorsal fin allows the tail vortex generated by the blunt body to couple and interfere with the tail vortex of the dorsal fin itself. This enhances the intensity of vortex shedding within the speed range of fish cruising, thereby increasing the excitation amplitude.

[0011] Preferably, the dorsal fin anchoring base has an adsorption mounting seat on the side near the fish's dorsal fin. The adsorption mounting seat has a flexible base and an adsorption groove extending perpendicular to the water flow direction. The adsorption mounting seat is located on the side of the dorsal fin anchoring base that contacts the surface of the fish's dorsal fin. Its function is to enhance the adhesion stability between the anchoring base and the dorsal fin using hydrodynamic effects. The main body of the adsorption mounting seat is a flexible base, which is pressed against the dorsal fin surface when the anchoring pin is locked. Its elastic deformation can adapt to the microscopic undulations of the dorsal fin surface, eliminating gaps and forming a good sealing contact interface. The surface of the flexible base has adsorption grooves, and the extension direction of the adsorption grooves is designed to be perpendicular to the water flow direction. When the fish swims, the water flows along the longitudinal axis of the fish's body across the surface of the adsorption mounting seat. When the water flows through the laterally extending adsorption groove, the abrupt change in the cross-section of the flow channel within the groove causes a local increase in flow velocity and a decrease in static pressure, forming a negative pressure zone relative to the external water pressure within the adsorption groove. The negative pressure generates an adsorption force perpendicular to the dorsal fin surface and directed towards the adsorption mount, pressing the anchor base more firmly against the dorsal fin surface.

[0012] Preferably, the acoustic cabin includes a transponder chip and circuit components. The transponder chip is a storage medium that stores a unique identification code. It is woken up by at least two wake-up signals and emits acoustic signals only when two or more wake-up signals are received at the same time. The circuit components include a full-bridge rectifier, capacitors, and a power management chip, which has an undervoltage lockout circuit.

[0013] The alternating current signal generated by the piezoelectric film on the bistable acquisition beam first enters the full-bridge rectifier, which converts the alternating current into pulsating direct current. The rectified power is then sent to the capacitor for storage and buffering. The capacitor acts as an energy pool, accumulating power when idle and releasing a large current instantaneously when needed for transmission. The power management chip monitors the voltage status of the capacitor, and its built-in undervoltage lockout circuit ensures that the load is only allowed to be connected when the capacitor voltage reaches a preset threshold, which is the minimum voltage sufficient to support a complete acoustic transmission. This avoids energy consumption caused by the capacitor repeatedly attempting to start when the voltage is insufficient.

[0014] The transponder chip stores the unique identification code of the individual fish. The chip uses a triggering logic of at least two wake-up signals—that is, the transmitting circuit is activated to emit an acoustic signal containing the identification code only when the chip receives at least two independent wake-up signals at the same time.

[0015] Preferably, the dorsal fin anchoring base is also provided with a pressure sensing membrane, which is arranged perpendicular to the water flow direction to detect the water flow pressure acting on the dorsal fin anchoring base when the fish swims. The pressure sensing membrane is electrically connected to the transponder chip. The transponder chip is configured to remain in a dormant state when the water flow pressure detected by the pressure sensing membrane is lower than a preset threshold, and to continuously generate a wake-up signal when the water flow pressure is higher than the preset threshold.

[0016] A pressure-sensing membrane, integrated as a swimming state sensor, is positioned perpendicular to the water flow direction on the surface of the dorsal fin anchoring base. When fish swim in deep-sea aquaculture cages, the water flow impacts the surface of the pressure-sensing membrane, generating a dynamic pressure force proportional to the square of the flow velocity. This dynamic pressure is converted into an electrical signal by the pressure-sensing membrane. The pressure-sensing membrane is electrically connected to a transponder chip, continuously transmitting the detected dynamic pressure signal to the chip's wake-up logic circuit. The chip's built-in comparator compares the real-time dynamic pressure value with a preset threshold: when the dynamic pressure is below the threshold, the chip determines that there are no effective energy harvesting conditions and therefore remains in deep sleep mode; when the dynamic pressure is above the threshold, the chip determines that energy harvesting conditions are available, and the pressure-sensing membrane continuously generates a wake-up signal, which is sent to the wake-up logic input of the transponder chip.

[0017] Preferably, at least two wake-up signals include a first wake-up signal generated by a pressure-sensing membrane and a second wake-up signal triggered by an external acoustic interrogation signal. The transponder chip emits an acoustic signal only when it receives both the first and second wake-up signals simultaneously.

[0018] This preferred scheme specifies the dual wake-up signals as a first wake-up signal and a second wake-up signal. The two wake-up signals are defined as an "AND" relationship in the wake-up logic circuit of the transponder chip—both signals must be present simultaneously for the chip to enter the transmission state. When the fish is still, dead, or the device detaches, the first wake-up signal is low; even if an external reader transmits an interrogation signal, the chip will not transmit due to the lack of the first wake-up signal. Only when the fish is swimming at a certain speed and clearly alive does the first wake-up signal become high. At this time, the chip receives the first wake-up signal and enters a semi-wake-up standby state. When an external reader transmits an interrogation signal at this time, the chip receives the second wake-up signal, and the chip activates the transmission circuit, using the electrical energy accumulated in the capacitor to emit an acoustic signal containing a unique identification code. After transmission, the chip automatically returns to the standby state to await the next interrogation.

[0019] Preferably, the air cavity is a sealed cavity, and an isolation wall is provided between the air cavity and the acoustic chamber. The air cavity is located inside the dorsal fin anchoring base on the side close to the acoustic chamber.

[0020] The air cavity is the core structure of this device, enabling near-neutral buoyancy in water. Specifically, it is a sealed cavity structure inside the dorsal fin anchoring base. The air cavity and the acoustic chamber are physically isolated within the base by a partition wall. The air cavity is located in the internal space of the base closer to the acoustic chamber, which houses the circuit components and transponder chip. The key functions of this partition wall are: firstly, to separate the sealed air of the air cavity from the electronic components of the acoustic chamber, preventing air from the air cavity from entering the acoustic chamber and causing circuit corrosion; secondly, the partition wall acts as a structural baffle, enhancing the overall rigidity of the dorsal fin anchoring base. The air cavity is designed as a sealed chamber filled with atmospheric pressure air. When the device is immersed in water, the air inside the air cavity is trapped and cannot escape, increasing the volume of water displaced and thus providing upward buoyancy. By precisely designing the volume of the air cavity, the overall average density of the device can be made close to that of seawater, achieving a near-neutral buoyancy state in water.

[0021] This invention offers the following advantages: The minimally invasive fixation structure, comprised of a dorsal fin anchoring base and anchoring pins, combined with flexible elements that adaptively follow fish growth, and near-neutral buoyancy compensation via an air cavity, significantly reduces the impact of the device on fish swimming behavior and growth. Utilizing the large-amplitude cross-well vibration characteristics of the bistable acquisition beam under low-frequency fluid alternating excitation, it achieves efficient acquisition and conversion of swimming energy from farmed fish. Combined with capacitor energy storage and undervoltage lockout management, it provides reliable self-powered protection for the transponder chip. The pressure sensing membrane is electrically connected to the transponder chip, forming a dual wake-up mechanism through water flow pressure and external acoustic interrogation signals. This ensures that the transponder chip only emits acoustic signals when the fish is swimming and actively interrogated externally, reducing ineffective power consumption, significantly extending effective working time, and lowering aquaculture management costs and tagging operation complexity. Attached Figure Description

[0022] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0023] Figure 1 A schematic diagram of the structure of a digital identity identification and binding device for live fish farmed in deep-sea environments.

[0024] Figure 2 A side view of a device for digital identification and binding of live fish in deep-sea aquaculture.

[0025] Figure 3 A front view of a digital identity identification and binding device for live fish farmed in deep-sea environments.

[0026] Figure 4 This is a schematic diagram of the structure of the dorsal fin anchoring base and the fin of the present invention.

[0027] Figure 5 This is a cross-sectional view of the dorsal fin anchoring base of the present invention.

[0028] Figure 6 This is a partially enlarged view of the dorsal fin anchoring base of the present invention.

[0029] Legend: 1. Dorsal fin anchoring base; 11. Anchoring pin hole; 12. Pressure sensing membrane; 13. Adsorption mounting base; 14. Circuit assembly; 15. Air cavity; 16. Transponder chip; 17. Capacitor; 2. Bistable acquisition beam; 3. Blunt body; 4. Anchoring pin; 5. Flexible element; 6. Fish dorsal fin. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] like Figure 1 and Figure 2As shown, the deep-sea aquaculture live fish digital identification and binding device includes a dorsal fin anchoring base 1. The tail of the dorsal fin anchoring base 1 is provided with a bistable acquisition beam 2. One end of the bistable acquisition beam 2 is connected to the dorsal fin anchoring base 1, and the other end is a free end. The surface of the dorsal fin anchoring base 1 is provided with an anchoring pin hole 11, an adsorption mounting seat 13, and a pressure sensing membrane 12. The interior of the dorsal fin anchoring base 1 is provided with an air cavity 15 and an acoustic chamber. The bistable acquisition beam 2 also includes a blunt body 3, which is fixed to the free end of the bistable acquisition beam 2 and is used to interact with the water flow to generate alternating excitation. The acoustic chamber is provided with a transponder chip 16, which is used to emit acoustic signals containing fish identification.

[0032] The device employs an external dorsal fin anchoring scheme, fixed to the base of the dorsal fin of the farmed fish via a dorsal fin anchoring base 1. When the fish is swimming, the water flow impacts the blunt body 3 fixed to the free end of the bistable acquisition beam 2. Under the action of unidirectional water flow, the blunt body 3 generates periodic vortices and detaches, forming alternating lift excitation of the bistable acquisition beam 2. Under alternating excitation, the bistable acquisition beam 2 undergoes large-amplitude jump vibrations between its two stable bending equilibrium states. The piezoelectric film attached to the beam surface generates alternating electrical signals as the beam bends and deforms. This electrical signal is processed by the circuit component 14 in the acoustic chamber and provides operating power to the transponder chip 16. When an external reader sends an interrogation signal, the transponder chip 16 is activated and uses stored electrical energy to emit an acoustic signal containing the unique identifier of the fish. The reader receives and decodes the signal to complete individual identification. The air cavity 15 provides buoyancy compensation for the device, making it close to neutral buoyancy in the water and avoiding additional weight burden on the normal swimming of the fish.

[0033] This device utilizes the fluid energy generated by the fish's own swimming to provide power, eliminating the need for battery replacements and theoretically allowing it to operate continuously throughout the entire fish rearing cycle. The dorsal fin fixation method avoids the trauma and infection risks associated with abdominal implantation surgery, while the air chamber 15 design minimizes the device's impact on the fish's swimming energy consumption. The broadband response characteristics of the bistable acquisition beam 2 enable it to effectively harvest energy at various swimming speeds.

[0034] like Figure 2As shown, the dorsal fin anchoring base 1 includes an anchoring pin 4 for passing through the fin rays of the fish's dorsal fin. The diameter of the anchoring pin 4 is smaller than the spacing between the fin rays of the fish's dorsal fin. The anchoring pin 4 is the core actuator that establishes a mechanical connection between the device and the fish's dorsal fin. The fish's dorsal fin consists of multiple parallel fin rays and fin membranes between them, with a certain natural spacing between the fin rays. During installation, a micro-hole slightly smaller than the spacing between the fin rays is formed by piercing the fin membrane at the connective tissue between the fin rays using a medical piercing instrument. Then, the anchoring pin 4 is passed through this micro-hole, or the anchoring pin 4 is sterilized and directly penetrates the fin membrane. After the anchoring pin 4 passes through the dorsal fin, its head is located on one side of the dorsal fin, and the anchoring pin hole 11 of the dorsal fin anchoring base 1 is located on the other side of the dorsal fin. The two are connected by the rod of the anchoring pin 4 to form a clamping fixation. The diameter of the anchoring pin 4 is designed to be smaller than the natural spacing between the fin rays to ensure that the anchoring pin 4 does not compress or damage the bony tissue of adjacent fin rays when passing through the fin membrane. Anchor pin 4 penetrates the flexible connective tissue between the fin rays rather than the fin rays themselves, therefore it has no substantial impact on the structural integrity and mechanical load-bearing capacity of the dorsal fin. After insertion, the clamping force between the head of anchor pin 4 and the dorsal fin anchoring base is maintained by the elastic deformation of the dorsal fin rays and the frictional resistance of the connective tissue, thus achieving a firm fixation of the device.

[0035] The anchoring pin 4, with a diameter smaller than the fin ray spacing, ensures that the anchoring pin 4, passing through the dorsal fin, will not damage the fin ray bony structure during the fixation process and subsequent growth, avoiding the risk of fracture, necrosis, or infection. Some studies have shown that after microporous penetration of the dorsal fin membrane in bony fish, the membrane can completely heal within weeks, and the anchoring pin 4 is wrapped by connective tissue to form a biological sheath, further enhancing the long-term stability of the fixation. Because this invention features a relatively long bistable acquisition beam 2, the anchoring pin 4 has higher resistance to detachment during penetration fixation; even if the fish collides or swims at high speed, the anchoring pin 4 will not slip off the dorsal fin. Compared to intraperitoneal implantation, this method requires no surgery or sutures, causes minimal acute trauma to the fish, and can be quickly deployed on-site, making it suitable for individual identification operations in large-scale aquaculture groups.

[0036] like Figure 2As shown, in this embodiment, the dorsal fin anchoring base 1 is provided with two anchoring pins 4. The heads of the anchoring pins 4 and the dorsal fin anchoring base 1 are located on both sides of the fish's dorsal fin, and the heads of the anchoring pins 4 are connected by a flexible element 5. The heads of the anchoring pins 4 are located on the dorsal surface of the dorsal fin, and the anchoring base is located on the ventral surface of the dorsal fin, with both clamping the dorsal fin from both sides. Crucially, the heads of the two anchoring pins 4 are connected by braided polyester thread, forming a U-shaped structure. This flexible element 5 allows the spacing between the heads of the two anchoring pins 4 to automatically adjust as the fish grows and the dorsal fin shape changes. When the fish grows and the fin spacing increases, the flexible element 5 stretches to adapt. The flexible element 5 also serves as an anti-detachment function: even if one anchoring pin 4 is accidentally detached from the fin membrane, the other anchoring pin 4 remains connected to the detached anchoring pin 4 through the flexible element 5, preventing the entire device from being lost.

[0037] The primary benefit of multi-point anchoring is anti-rotation fixation. In a single-anchor pin scheme, the device may rotate around the axis of the anchor pin 4, causing the orientation of the bistable acquisition beam 2 to deviate from the design direction, thus weakening the fluid energy harvesting efficiency. The dual-support constraint formed by the two anchor pins 4 fundamentally eliminates the degree of freedom of rotation around the axis, ensuring that the acquisition beam always aligns with the water flow direction. The flexible element 5 conforms to adaptive growth following. The cultivation cycle of deep-sea aquaculture fish is typically 12-36 months, during which the fish size may increase several times, and the spacing between the dorsal fin rays also increases. A rigid multi-pin system will experience stress concentration due to fish growth, and may even cause deformation of the fin rays or anchor pins 4. The adaptive tensile capability of the flexible element 5 allows the anchoring system to grow with the fish throughout its entire life cycle.

[0038] like Figure 2 As shown, the bistable acquisition beam 2 is offset at the tail of the dorsal fin anchoring base 1 on the side close to the dorsal fin of the fish. When the dorsal fin anchoring base 1 is fixed, the centerline of the bistable acquisition beam 2 is located on the extension line of the centerline of the fish's dorsal fin. In this embodiment, the bistable acquisition beam 2 is composed of two metal sheets, a W-shaped metal beam, and two piezoelectric films. The metal sheets have two stable bending equilibrium states. The piezoelectric films are attached to the inner side of the metal sheets, and the W-shaped metal beam is clamped on the inner side of the piezoelectric films to improve the fatigue strength of the bistable acquisition beam 2.

[0039] The bistable acquisition beam 2 adopts an offset installation layout, with the fixed end of the beam connected to the tail of the anchor base near the dorsal fin of the fish. This arrangement aims to allow the free end of the beam and its connected blunt body 3 to extend rearward along the dorsal fin midline, ensuring that the beam midline is collinear with the dorsal fin midline. When the fish sways left and right, the dorsal fin, as an extension of the fish's longitudinal axis, experiences its largest sway amplitude at the fin's midline and smallest at its edge. Aligning the acquisition beam midline with the dorsal fin midline allows the beam to obtain the maximum lateral displacement input under the base excitation of the fish's swaying, thereby driving the beam to undergo large-amplitude jump vibrations between the two steady states. Structurally, the beam employs at least two stacked metal sheets. During manufacturing, mechanical pre-bending or in-plane displacement constraints pre-deform the sheets, creating two stable bending equilibrium states with opposite curvature directions. A piezoelectric film is tightly bonded to the surface of the metal sheets. When the sheets undergo sudden jump bending between steady states, the piezoelectric film withstands tensile and / or compressive strain, converting mechanical strain energy into electrical energy using the positive piezoelectric effect.

[0040] The installation method of the aforementioned bistable acquisition beam 2 is to maximize the excitation input. The dorsal fin midline is the area with the largest displacement amplitude when the fish swings. Aligning the acquisition beam with this area means that, under the same fish swing amplitude, the beam's base excitation amplitude is the largest, and the probability of triggering cross-well vibration is the highest. Compared with traditional nonlinear piezoelectric beams, the jump mechanism of the bistable acquisition beam 2 allows it to generate large-amplitude vibrations even under low-frequency excitation, overcoming the inherent defect of linear beams requiring high-frequency resonance matching. The stacking of multiple metal sheets improves the structural strength and fatigue life of the beam. Since this invention is used for long-term monitoring, the beam needs to withstand millions of bending cycles. The stacked structure distributes stress among multiple sheets, and the piezoelectric film is attached to the surface rather than embedded inside, simplifying the manufacturing process and facilitating subsequent maintenance and replacement.

[0041] like Figure 2 As shown, the blunt body 3 is a D-shaped horizontal cross-section. The arc surface of the blunt body 3 faces the dorsal fin of the fish, while the chord surface faces away from the dorsal fin. The chord surface of the blunt body 3 is perpendicular to the water flow direction. The blunt body 3 adopts a D-shaped cross-section, with its arc surface facing the back of the fish and the chord surface facing outward, and the chord surface plane is perpendicular to the water flow direction. When the water flows over the D-shaped blunt body 3, the arc surface faces the flow, allowing the water to smoothly adhere to the surface of the blunt body 3 and gradually accelerate under the geometric guidance of the arc surface. When the water flows to the sharp edge of the trailing edge of the blunt body 3, due to the geometric abrupt change, the boundary layer undergoes deterministic flow separation at that point, forming alternating vortices downstream of the blunt body 3. During the vortex shedding process, the blunt body 3 is subjected to a periodic lateral force perpendicular to the water flow direction. This alternating lift force drives the bistable acquisition beam 2 to reciprocate across the trap between its two steady states. The design of the D-shaped blunt body 3 with its arc surface facing the dorsal fin allows the tail vortex generated by the blunt body 3 to couple and interfere with the tail vortex of the dorsal fin itself. This enhances the intensity of vortex shedding within the speed range of fish cruising, thereby increasing the excitation amplitude.

[0042] The advantage of the D-shaped blunt body 3 over the traditional cylindrical blunt body lies in its deterministic flow separation point. The flow separation point of a cylindrical blunt body moves across the cylindrical surface with changes in Reynolds number. Seasonal influences cause changes in seawater temperature, affecting seawater viscosity and thus altering the Reynolds number, leading to instability in the frequency and amplitude of vortex-induced vibrations. The edges of the D-shaped blunt body 3 lock the separation point in a fixed position, keeping the vortex shedding frequency stable over a wide flow velocity range and better matching the natural frequency of the bistable beam.

[0043] The arrangement of the chord surface perpendicular to the direction of water flow ensures that the direction of the lateral lift is perpendicular to the bending plane of the beam, so that the excitation energy is fully used to drive the beam's cross-well vibration and avoids energy loss caused by oblique excitation.

[0044] like Figure 3 As shown, the dorsal fin anchoring base 1 has an adsorption mounting seat 13 on the side near the dorsal fin of the fish. The adsorption mounting seat 13 has a flexible base and an adsorption groove extending perpendicular to the water flow direction. The adsorption mounting seat 13 is located on the side of the dorsal fin anchoring base 1 that contacts the surface of the fish's dorsal fin. Its function is to enhance the adhesion stability between the anchoring base and the dorsal fin by utilizing hydrodynamic effects. The main body of the adsorption mounting seat 13 is a flexible base. When the anchoring pin 4 is locked, the flexible base is pressed against the surface of the dorsal fin. Its elastic deformation can adapt to the microscopic undulations of the dorsal fin surface, eliminate gaps, and form a good sealing contact interface. The surface of the flexible base has an adsorption groove, and the extension direction of the adsorption groove is designed to be perpendicular to the water flow direction. When the fish swims, the water flows along the longitudinal axis of the fish through the surface of the adsorption mounting seat 13. When the water flows through the laterally extending adsorption groove, the abrupt change in the cross-section of the flow channel in the groove causes a local increase in flow velocity and a decrease in static pressure, forming a negative pressure zone relative to the external water pressure in the adsorption groove. The negative pressure generates an adsorption force perpendicular to the dorsal fin surface and pointing towards the adsorption mounting base 13, which presses the anchoring base more firmly against the dorsal fin surface.

[0045] The adsorption mounting base 13, in conjunction with the anchoring pin 4, improves the attachment stability of the device under conditions of high-speed swimming and sharp turns. The elastic fit of the flexible base also has the following additional effects: eliminating stress concentration in the line contact between the anchoring base and the dorsal fin surface, avoiding pressure tissue necrosis caused by long-term wear; forming a sealed interface to prevent the accumulation of mud and microorganisms between the anchoring base and the dorsal fin, thus reducing wear on the fish's dorsal fin and decreasing the risk of infection.

[0046] like Figure 5 As shown, the acoustic cabin includes a transponder chip 16 and a circuit assembly 14. The transponder chip 16 is a storage medium that stores a unique identification code. It is woken up by at least two wake-up signals and emits acoustic signals only when two or more wake-up signals are received at the same time. like Figure 6As shown, circuit component 14 includes a full-bridge rectifier, capacitor 17, and a power management chip, which is equipped with an undervoltage lockout circuit.

[0047] The alternating current signal generated by the piezoelectric film on the bistable acquisition beam 2 first enters the full-bridge rectifier, converting the alternating current into pulsating direct current. The rectified power is then sent to capacitor 17 for storage and buffering. Capacitor 17 acts as an energy pool, accumulating power when idle and releasing a large current instantaneously when needed for transmission. The power management chip monitors the voltage state of capacitor 17, and its built-in undervoltage lockout circuit ensures that the load is only allowed to be connected when the voltage of capacitor 17 reaches a preset threshold, which is the minimum voltage sufficient to support a complete acoustic transmission. This prevents energy consumption caused by repeated attempts to start when the voltage of capacitor 17 is insufficient. The transponder chip 16 stores the unique identification code of the individual fish. The chip uses a trigger logic of at least two wake-up signals—that is, the transmitting circuit is activated to emit an acoustic signal containing the identification code only when the chip receives at least two independent wake-up signals simultaneously.

[0048] Transponders typically employ timed transmission or single-signal wake-up modes, resulting in numerous invalid transmissions and wasted power. Undervoltage lockout circuitry further ensures transmission quality, guaranteeing sufficient power for each transmission.

[0049] like Figure 4 As shown, the dorsal fin anchoring base 1 is also equipped with a pressure sensing membrane 12, which is arranged perpendicular to the water flow direction to detect the water flow pressure acting on the dorsal fin anchoring base 1 when the fish swims; it is worth noting that Figure 4 The dorsal fin of the fish depicted is not the actual shape of a dorsal fin, and the invention is much smaller in shape and size than a fish's dorsal fin. Figure 4 It is only used to indicate the fixing direction relationship between the dorsal fin anchoring base 1 and the dorsal fin of the fish.

[0050] The pressure sensing membrane 12 is electrically connected to the transponder chip 16. The transponder chip 16 is configured to remain in a sleep state when the water flow pressure detected by the pressure sensing membrane 12 is lower than a preset threshold, and to continuously generate a wake-up signal when the water flow pressure is higher than the preset threshold.

[0051] The pressure sensing membrane 12, integrated as a swimming state sensor, is mounted on the surface of the dorsal fin anchoring base 1, with its orientation perpendicular to the water flow direction. When fish swim in deep-sea aquaculture cages, the water flow impacts the surface of the pressure sensing membrane 12, generating a dynamic pressure force proportional to the square of the flow velocity. This dynamic pressure is converted into an electrical signal by the pressure sensing membrane 12. The pressure sensing membrane 12 is electrically connected to the transponder chip 16, continuously transmitting the detected dynamic pressure signal to the chip's wake-up logic circuit. The chip's built-in comparator compares the real-time dynamic pressure value with a preset threshold: when the dynamic pressure is below the threshold, it may mean that the fish is still, dead, or the invention has detached, in which case no signal needs to be emitted; when the dynamic pressure is above the threshold, the fish is clearly in a continuous active state, and the pressure sensing membrane 12 continuously generates a wake-up signal, which is sent to the wake-up logic input terminal of the transponder chip 16.

[0052] At least two wake-up signals include a first wake-up signal generated by the pressure sensing membrane 12 and a second wake-up signal triggered by an external acoustic interrogation signal. The transponder chip 16 emits an acoustic signal only when it receives both the first and second wake-up signals simultaneously.

[0053] Deep-sea farmed fish are usually in a low-activity state at night or after feeding. Traditional timed-launching tags still periodically consume power to launch during these periods, resulting in a large waste of energy.

[0054] This preferred scheme specifies the dual wake-up signals as a first wake-up signal and a second wake-up signal. The two wake-up signals are defined as an "AND" relationship in the wake-up logic circuit of the transponder chip 16—both signals must be present simultaneously for the chip to enter the transmission state. When the fish is still, dead, or the device detaches, the first wake-up signal is low; even if an external reader transmits an interrogation signal, the chip will not transmit due to the lack of the first wake-up signal. Only when the fish is swimming at a certain speed and clearly alive does the first wake-up signal become high. At this time, the chip receives the first wake-up signal and enters a semi-wake-up standby state. When an external reader transmits an interrogation signal at this time, the chip receives the second wake-up signal, and the chip activates the transmission circuit, using the electrical energy accumulated in capacitor 17 to emit an acoustic signal containing a unique identification code. After transmission, the chip automatically returns to the standby state to wait for the next interrogation. This configuration ensures that the transponder will not be falsely awakened by environmental noise; secondly, it eliminates the cycle of insufficient energy, failed transmission, and repeated transmission.

[0055] like Figure 5 As shown, the air cavity 15 is a sealed cavity, and an isolation wall is provided between the air cavity 15 and the acoustic chamber. The air cavity 15 is located inside the dorsal fin anchoring base 1 on the side close to the acoustic chamber.

[0056] The air cavity 15 is the core structure of the device for achieving near-neutral buoyancy in water. Specifically, it is a sealed cavity structure inside the dorsal fin anchoring base 1. The air cavity 15 is physically isolated from the acoustic chamber within the base by an isolation wall. The air cavity 15 is located in the internal space of the base near the acoustic chamber, which houses the circuit components 14 and the transponder chip 16. The key functions of this isolation wall are: firstly, to separate the sealed air of the air cavity 15 from the electronic components of the acoustic chamber, preventing air from the air cavity 15 from entering the acoustic chamber and causing circuit corrosion; secondly, the isolation wall acts as a structural partition, enhancing the overall rigidity of the dorsal fin anchoring base 1. The air cavity 15 is designed as a sealed cavity filled with atmospheric pressure air. When the device is immersed in water, the air inside the air cavity 15 is trapped inside and cannot escape, increasing the volume of water displaced, thus providing upward buoyancy for the device. By precisely designing the volume of the air cavity 15, the overall average density of the device can be made close to the density of seawater, achieving a near-neutral buoyancy state in water.

[0057] The beneficial effects of this invention include: the fixed structure can adaptively follow the growth of the fish, and combined with near-neutral buoyancy compensation, it significantly reduces the impact of the device on the swimming behavior and growth and development of the fish; the use of a bistable acquisition beam solves the problem of frequency matching difficulties in traditional linear piezoelectric energy harvesters, realizing efficient acquisition and conversion of swimming energy of farmed fish; the pressure sensing membrane is electrically connected to the transponder chip, and a dual wake-up signal is formed by the water flow pressure and the external acoustic interrogation signal, ensuring that the transponder chip only emits acoustic signals when the fish is swimming and is actively interrogated by the outside, which greatly reduces the power consumption of waste. It realizes maintenance-free digital identity tracking of deep-sea farmed fish throughout their entire life cycle from release to harvest, significantly extending the effective working time and reducing the cost of aquaculture management and the complexity of tagging operations.

[0058] The above embodiments and / or implementation methods are merely illustrative of preferred embodiments and / or implementation methods for realizing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art may make some modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but these should still be regarded as the technology or embodiments that are substantially the same as the present invention.

Claims

1. A digital identification and binding device for live fish cultured in deep-sea environments, comprising a dorsal fin anchoring base (1) and an air cavity (15) and an acoustic chamber disposed within the dorsal fin anchoring base (1), characterized in that, The tail of the dorsal fin anchoring base (1) is provided with a bistable acquisition beam (2), one end of which is connected to the dorsal fin anchoring base (1), and the other end is a free end; The bistable acquisition beam (2) also includes a blunt body (3), which is fixed to the free end of the bistable acquisition beam (2) and is used to interact with the water flow to generate alternating excitation; The acoustic cabin is equipped with a transponder chip (16) for transmitting acoustic signals containing fish identification identifiers; The dorsal fin anchoring base (1) includes at least two anchoring pins (4), the heads of the anchoring pins (4) and the dorsal fin anchoring base (1) are located on both sides of the dorsal fin (6) of the fish, and the heads of the anchoring pins (4) are connected by a flexible element (5).

2. The digital identity identification and binding device for live deep-sea aquaculture fish according to claim 1, characterized in that, The dorsal fin anchoring base (1) includes an anchoring pin (4) for passing through the fin rays of the fish's dorsal fin (6), the diameter of which is smaller than the fin ray spacing of the fish's dorsal fin (6).

3. The digital identity identification and binding device for live deep-sea aquaculture fish according to claim 1, characterized in that, The bistable acquisition beam (2) is offset at the tail of the dorsal fin anchoring base (1) on the side close to the dorsal fin (6) of the fish. When the dorsal fin anchoring base (1) is fixed, the centerline of the extension direction of the bistable acquisition beam (2) is located on the extension line of the centerline of the dorsal fin (6) of the fish.

4. The digital identity identification and binding device for live deep-sea aquaculture fish according to claim 1, characterized in that, The bistable acquisition beam (2) consists of at least two stacked metal sheets, each having two stable bending equilibrium states, and a piezoelectric film is attached to the surface of the metal sheets.

5. The digital identity identification and binding device for live deep-sea aquaculture fish according to claim 1, characterized in that, The blunt body (3) is a D-shaped horizontal cross section. The arc surface of the blunt body (3) faces the dorsal fin (6) of the fish, and the chord surface of the blunt body (3) faces away from the dorsal fin (6) of the fish. The chord surface of the blunt body (3) is perpendicular to the direction of water flow.

6. The digital identity identification and binding device for live deep-sea aquaculture fish according to claim 1, characterized in that, The dorsal fin anchoring base (1) is provided with an adsorption mounting seat (13) on the side near the dorsal fin (6) of the fish. The adsorption mounting seat (13) is provided with a flexible base and an adsorption groove extending perpendicular to the direction of water flow.

7. The digital identity identification and binding device for live deep-sea aquaculture fish according to claim 1, characterized in that, The acoustic cabin includes a transponder chip (16) and a circuit assembly (14). The transponder chip (16) is a storage medium that stores a unique identification code and emits an acoustic signal only when two or more wake-up signals are received at the same time. The circuit assembly (14) includes a full-bridge rectifier, a capacitor (17), and a power management chip, the power management chip having an undervoltage lockout circuit.

8. The digital identity identification and binding device for live deep-sea aquaculture fish according to claim 7, characterized in that, The dorsal fin anchoring base (1) is also provided with a pressure sensing membrane (12), which is arranged perpendicular to the water flow direction and is used to detect the water flow pressure acting on the dorsal fin anchoring base (1) when the fish swims. The pressure sensing membrane (12) is electrically connected to the transponder chip (16). The transponder chip (16) is configured to: when the water flow pressure detected by the pressure sensing membrane (12) is lower than a preset threshold, the transponder chip (16) is configured to remain in a dormant state; when the water flow pressure is higher than the preset threshold, the pressure sensing membrane outputs a detection electrical signal, and the transponder chip generates a first wake-up signal based on the electrical signal.

9. The digital identity identification and binding device for live deep-sea aquaculture fish according to claim 8, characterized in that, The at least two wake-up signals include a first wake-up signal generated by the pressure sensing membrane (12) and a second wake-up signal triggered by an external acoustic interrogation signal. The transponder chip (16) emits an acoustic signal only when it receives the first wake-up signal and the second wake-up signal simultaneously.

10. The digital identity identification and binding device for live deep-sea aquaculture fish according to claim 1, characterized in that, The air cavity (15) is a sealed cavity. An isolation wall is provided between the air cavity (15) and the acoustic chamber. The air cavity (15) is located inside the dorsal fin anchoring base (1) on the side close to the acoustic chamber.

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