Bionic fish based on piezoelectric wafer driving and control method thereof

Abstract

This invention discloses a piezoelectric crystal-driven bionic fish and its control method. The bionic fish includes a driving component, an external structural component, and a motion transmission component. The driving component consists of four substrate segments connected sequentially, each with a connector allowing for mutual rotation. The external structural component comprises a fish head, while the motion transmission component consists of four hinged segments representing the fish body and tail. The fourth substrate is connected to the fish tail via gear engagement, enabling mutual rotation. The fish head is connected to the first substrate via a pin hinge, allowing mutual rotation between the fish head and the first substrate. This invention, by arranging the substrates and piezoelectric crystal arrays and controlling the input voltage of each piezoelectric crystal, combined with the proposed four-segment fish body turning angle control method and bionic fish swaying speed control method, achieves high precision, high maneuverability, high reliability, high dynamic response, good interchangeability, and high scalability.

Description

Technical Field

[0001] This invention relates to the technical field of underwater biomimetic fish, and more particularly to a biomimetic fish based on piezoelectric dual-chip drive and its control method. Background Technology

[0002] Multidimensional perception and intelligent development of marine resources have become a strategic high ground in global technological competition. Underwater biomimetic robots, based on biomimetic fluid dynamics and smart materials technologies, have overcome the technological bottlenecks of traditional ROVs / RUVs in terms of adaptability to complex flow fields, covert motion efficiency, and environmental interaction, thanks to their low-fluid-resistance morphological design, efficient biomimetic propulsion mechanisms, and multimodal maneuverability. These biomimetic platforms, through high-fidelity biomimetic motion design, have achieved disruptive applications in key scenarios such as in-situ monitoring of the deep-sea environment, detailed mapping of seabed topography, and covert detection in ecologically sensitive areas. The integrated innovation of their dynamic deformation mechanisms and intelligent motion control systems is driving the underwater operation paradigm towards biomimetic self-consistency and swarm intelligence. Current technological frontiers focus on cross-media motion fusion, flexible-driven topology optimization, and bio-inspired environmental perception, aiming to build a new generation of autonomous marine cognition and operation systems.

[0003] Chinese patent application CN119190317A discloses a multi-functional underwater vehicle employing multi-thruster cooperative control technology. Through differentiated drive strategies, it achieves attitude adjustment, variable speed movement, and cruise state maintenance in three-dimensional space, effectively enhancing the motion control dimensions of traditional underwater vehicles. However, this approach still has limitations in propulsion system energy efficiency optimization, maneuverability in complex fluid environments, and modular functional expansion architecture design. It has not yet overcome the inherent technical bottlenecks of low energy utilization, insufficient dynamic agility, and weak system adaptability inherent in traditional underwater vehicles.

[0004] Chinese patent application CN119460038A discloses a parallel biomimetic robotic fish system based on a multi-degree-of-freedom parallel drive mechanism. This system uses distributed motor units to control the pectoral fin angle-of-attack adjustment mechanism, dorsal fin deflection mechanism, and caudal fin wave motion drive unit, enabling the biomimetic fish to achieve vertical buoyancy, three-dimensional attitude adjustment, and propulsion mode switching. This technology significantly improves the underwater biomimetic body's motion mimicry and environmental adaptability through the coordinated motion reconstruction of biomimetic fins. However, the dorsal fin actuator suffers from insufficient hydrodynamic load matching during dynamic steering, resulting in effective torque attenuation and limited steering maneuverability. Furthermore, the redundant transmission chain design of the multi-stage linkage mechanical transmission system leads to overall structural redundancy, increasing the complexity of the mechanism and potentially restricting system reliability and maintainability. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a biomimetic fish driven by piezoelectric wafers. The biomimetic fish is divided into four segments, and the traditional motor drive is replaced with piezoelectric wafer drive, which is then arrayed axially to form a substrate with a four-segment PWM-controlled piezoelectric wafer array. By controlling the excitation voltage applied to the piezoelectric wafer array, the horizontal deflection angle of the substrate is controlled. Each segment of the substrate corresponds to the deflection angle of the fish body, ultimately enabling the biomimetic fish to turn and move forward. This achieves precise control of the biomimetic fish's position and has advantages such as high control accuracy, high reliability, high replaceability, and convenient assembly and disassembly.

[0006] To achieve the above objectives, the present invention provides a biomimetic fish driven by a piezoelectric wafer, the biomimetic fish comprising an external shape component, a driving component, and a motion transmission component.

[0007] The driving component includes four sequentially hinged substrates, with piezoelectric wafers connected to the corresponding substrates. The substrate assembly comprises four sequentially rotatable connected substrates. The lower end of the first substrate is provided with a second connector that connects to the second substrate. The connection method between adjacent substrates is the same, and both can rotate after connection. Furthermore, taking the connection between the first and second substrates as an example, the lower end of the first substrate meshes with the external gear at the upper end of the second substrate via a gear ring. The double-ear-shaped boss on the first substrate engages with the gear shaft hole on the external gear of the second substrate via a first connecting plate, allowing them to rotate relative to each other.

[0008] A piezoelectric wafer is disposed on opposite sides of a substrate, and the length of the piezoelectric wafer is 5 / 6 to 2 / 3 of the length of the jet plate to which it is connected. A connecting wire to the piezoelectric wafer allows a DC voltage to be applied to the piezoelectric wafer, causing the jet plate connected to it to deflect.

[0009] The outer component includes a fish head, the lower end of which includes a double-hook hinge boss. The fish head pin passes through the double-hook hinge boss and is hinged to the first base plate, allowing the fish head and the first base plate to rotate relative to each other.

[0010] The motion transmission components consist of four segments of the fish body and tail connected in sequence.

[0011] The fish body assembly consists of four fish body segments connected in sequence. These segments are hinged together by connectors on each fish body segment, allowing them to rotate relative to each other. Each fish body segment is rigidly connected to its corresponding base plate by a fish body pin.

[0012] The fish tail is connected to the fourth base plate via a fourth connector at its lower end. Furthermore, the fish tail is rotatably connected to the fourth base plate via the fourth connector. The connection between the fourth base plate and the fish tail is as follows: the lower end of the fourth base plate contains an external gear set, and the upper end of the fish tail also has the same external gear set. The fourth base plate and the fish tail are connected via a connecting plate hole and shaft engagement, allowing them to rotate relative to each other.

[0013] By distributing the substrate array using the above technical solution, the small mass of each substrate can improve the turning accuracy of the bionic fish. Compared with traditional motor-driven bionic fish, this application uses piezoelectric chips to achieve high-frequency movement and high-precision control of the substrate corresponding to the fish body. In terms of driving method, the required turning angle and forward distance of the bionic fish can be calculated in real time based on the target point and the current position of the bionic fish. By adjusting the excitation voltage of different substrates, the turning angle and forward speed of the bionic fish can be precisely controlled, thereby achieving precise control of the position of the bionic fish.

[0014] A driving method for a biomimetic fish based on piezoelectric wafers, wherein the substrate group includes four substrates arranged in sequence as a first substrate, a second substrate, a third substrate and a fourth substrate, and the maximum horizontal deflection angle of each substrate is the same as θmax.

[0015] The control method is as follows:

[0016] Step 1: Obtain the target's position coordinates (x, y).

[0017] Step 2: Input the current position coordinates (x1, y1) of the bionic fish.

[0018] Step 3: Calculate the corresponding turning angle θ based on the target coordinate position and the bionic fish coordinate position.

[0019] Step 4: Determine whether the bionic fish needs to turn based on the calculated required turning angle θ value.

[0020] If the turning angle |θ| ≥ 0.1°, the bionic fish needs to turn, and then proceed to step 5.

[0021] If the turning angle |θ| < 0.1°, the bionic fish does not need to turn and proceeds directly to step 17.

[0022] Step 5: Determine whether |θ| is less than or equal to 20°.

[0023] If |θ| is less than or equal to 20°, proceed directly to step 9.

[0024] If |θ| is greater than 20°, proceed directly to step 6.

[0025] Step 6: The first substrate 28, the second substrate 24, and the third substrate 20 all need to be excited by voltage U0, and the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be excited by driving voltage U0 interchangeably.

[0026] If θ is positive, then excitation voltage U0 is applied to the first left piezoelectric chip 30, the second left piezoelectric chip 24, and the third left piezoelectric chip 22, while the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be excited by excitation voltage U0 applied alternately.

[0027] If θ is negative, then excitation voltage U0 is applied to the first right piezoelectric chip 29, the second right piezoelectric chip 25, and the third right piezoelectric chip 21, while the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be excited by excitation voltage U0 applied alternately.

[0028] Step 7: Obtain the new current position coordinates (x3, y3) of the bionic fish.

[0029] Step 8, return to step 2.

[0030] Step 9: Determine which range the turning angle θ falls within.

[0031] If 1°≤|θ|≤5°, then proceed to step 10.

[0032] If 5° < |θ| ≤ 10°, proceed to step 12.

[0033] If 10° < |θ| ≤ 20°, then proceed to step 14.

[0034] Step 10: The first substrate 28 needs to be stimulated with a voltage of 0.25U0. The second substrate 24 and the third substrate 20 do not need to be stimulated with a voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be stimulated with a driving voltage of 0.25U0.

[0035] If θ is positive, a voltage of 0.25U0 is applied to the first left piezoelectric chip 30 for excitation, while the second left piezoelectric chip 24 and the third left piezoelectric chip 22 are not applied with excitation voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be applied with excitation voltage of 0.25U0 respectively.

[0036] If θ is negative, a voltage of 0.25U0 is applied to the first right piezoelectric chip 29 for excitation, while the second right piezoelectric chip 25 and the third right piezoelectric chip 21 are not excitation voltages applied. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be excitation voltages of 0.25U0 applied interchangeably.

[0037] Step 11, proceed directly to step 15.

[0038] In step 12, the first substrate 28 needs to be stimulated with a voltage of 0.5U0, the second substrate 24 and the third substrate 20 do not need to be stimulated with voltage, and the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be stimulated with a driving voltage of 0.25U0.

[0039] If θ is positive, a voltage of 0.5U0 is applied to the first left piezoelectric chip 30 for excitation, while the second left piezoelectric chip 24 and the third left piezoelectric chip 22 are not applied with excitation voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be applied with an excitation voltage of 0.25U0.

[0040] If θ is negative, a voltage of 0.5U0 is applied to the first right piezoelectric chip 29, and no excitation voltage is applied to the second right piezoelectric chip 25 and the third right piezoelectric chip 21. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate 4 substrate 16 need to be driven by an excitation voltage of 0.25U0.

[0041] Step 13, proceed directly to step 15.

[0042] In step 14, the first substrate 28 needs to be stimulated by voltage U0, while the second substrate 24 and the third substrate 20 do not need to be stimulated by voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be stimulated by driving voltage 0.25U0 interchangeably.

[0043] If the value of θ is positive, a voltage U0 is applied to the first left piezoelectric chip 30 for excitation, while the second left piezoelectric chip 24 and the third left piezoelectric chip 22 are not applied with excitation voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be applied with an excitation voltage of 0.25U0.

[0044] If θ is negative, then voltage U0 is applied to the first right piezoelectric chip 29, and no excitation voltage is applied to the second right piezoelectric chip 25 and the third right piezoelectric chip 21. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate 4 substrate 16 need to be driven by an excitation voltage of 0.25U0.

[0045] Step 15: Obtain the new current position coordinates (x2, y2) of the bionic fish.

[0046] Step 16, return to step 2.

[0047] Step 17: Calculate the distance Length between the current coordinates (x1, y1) and the target coordinates (x, y) of the bionic fish.

[0048]

[0049] Step 18: Determine if the Length value is less than or equal to 1.

[0050] If Length > 1, the bionic fish needs to move forward, and then proceed to step 19.

[0051] If Length≤1, the bionic fish does not need to move forward and can directly proceed to step 22.

[0052] In step 19, the first substrate 28, the second substrate 24, and the third substrate 20 do not require voltage excitation, while the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be driven by the driving voltage kU0.

[0053] Step 20: Obtain the new current position coordinates of the bionic fish (x4, y4).

[0054] Step 21, return to step 2.

[0055] Step 22: Execute the end command.

[0056] By employing the above technical solutions, the beneficial effects of the present invention are as follows:

[0057] Compared to traditional bionic fish, this invention uses four substrates with piezoelectric crystals as the driving components. These four substrates are arranged in an axial array, resulting in a small mass and high flexibility. By dividing the bionic fish's motion transmission components into four body and tail segments, the turning and forward driving mechanisms are precisely segmented. Each substrate is rigidly connected to its corresponding body segment, allowing each segment to be controlled by a specific substrate for turning. The tail is connected to a fourth substrate, and by controlling the excitation voltage of the piezoelectric crystals on that substrate, the tail can swing left and right. This flexible control of the body movements corresponding to each substrate segment enhances the overall controllability of the fish's turning angle. Furthermore, the use of piezoelectric crystals enables high-frequency motion and high-precision control, improving the overall rotational accuracy of the bionic fish, which is superior to that of traditional bionic fish.

[0058] Because of the piezoelectric crystal array proposed in this invention, and by using the piezoelectric crystals to achieve high-frequency motion and high-precision control, the overall rotation accuracy of the bionic fish can be improved, which is superior to the rotation accuracy of traditional bionic fish. In terms of the driving method, the optimal combination of piezoelectric crystal array driving can be selected according to the turning angle and the forward proximity distance corresponding to the target position coordinates to achieve high-precision motion control. By automatically selecting a higher-precision piezoelectric crystal driving scheme by changing the turning angle, the precise closed-loop control of the bionic fish position can be achieved.

[0059] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0060] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0061] Figure 1 A two-dimensional cross-sectional view of a piezoelectric wafer-driven bionic fish provided in an embodiment of the present invention;

[0062] Figure 2 This is a schematic diagram of the installation of the internal drive components of the mechanical bionic fish provided in an embodiment of the present invention;

[0063] Figure 3 This is a schematic diagram of the mechanical bionic fish shape provided in an embodiment of the present invention;

[0064] Figure 4 This is a schematic diagram of the installation of the first substrate and the second substrate provided in an embodiment of the present invention;

[0065] Figure 5 This is a schematic diagram of the installation of the fourth substrate and the fish tail according to an embodiment of the present invention;

[0066] Figure 6 This is a schematic diagram of the installation of the first fish body segment and the first substrate provided in an embodiment of the present invention;

[0067] Figure 7 This is a schematic diagram of the installation of the first and second fish body sections provided in an embodiment of the present invention;

[0068] Figure 8 A flowchart of the control method provided in an embodiment of the present invention;

[0069] Figure 9 This is a motion diagram provided for an embodiment of the present invention.

[0070] The reference numerals in the above figures are as follows: 1. Fish head; 101. Double-hook hinge boss; 102. Cylindrical through hole; 2. Fish head pin; 3. First fish body section; 301. Left double-hook type boss; 302. Cylindrical shaft; 303. Right double-hook type boss; 304. Two hook surfaces; 305. Single-sided through hole; 4. First fish body pin; 5. First connecting plate; 6. Second fish body section; 601. Left double-hook type boss; 602. Right double-hook type boss; 7. Second fish body pin; 8. Second connecting plate; 9. 10. Third fish body pin; 11. Third connecting plate; 12. Fourth fish body pin; 13. Fourth fish body; 14. Fish tail; 15. Fish tail connecting plate; 1501. Upper 3 / 4 retaining ring; 1502. Lower 3 / 4 retaining ring; 1503. Upper end face arc; 1504. Lower end face arc; 16. Fourth base plate; 1601. Gear set; 1602. Small gear shaft; 1603. Right shoulder; 1604. Left shoulder; 1605. Large gear shaft; 17. Fourth right piezoelectric crystal. ; 18. Fourth left piezoelectric chip; 19. Fourth connecting plate; 20. Third substrate; 21. Third right piezoelectric chip; 22. Third left piezoelectric chip; 23. Fifth connecting plate; 24. Second substrate; 2401. 1 / 3 external gear; 2402. Gear shaft; 2403. Left shoulder; 2404. Right shoulder; 25. Second right piezoelectric chip; 26. Second left piezoelectric chip; 27. Sixth connecting plate; 2701. 3 / 4 cylindrical hole; 2702. Lower 3 / 4 cylindrical hole; 28. 1. Substrate; 2801. Substrate through hole; 2802. Internal gear ring; 2803. Hinge boss; 2804. Hinge cylindrical hole; 2805. Double lug type boss; 2806. Shaft; 29. ​​First right piezoelectric chip; 30. First left piezoelectric chip; 31. First substrate connecting plate; 3101. Upper 3 / 4 retaining ring; 3102. Upper cylindrical surface; 3103. Lower cylindrical surface; 3104. Lower 3 / 4 retaining ring; 32. Second substrate connecting plate; 33. Third substrate connecting plate. Detailed Implementation

[0071] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0072] It should be noted that in the description of this invention, the terms "first," "second," etc., are used only for descriptive purposes and to distinguish similar objects; there is no order between them, nor should they be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "multiple" means two or more.

[0073] Example: This example discloses a mechanical bionic fish, comprising:

[0074] The mechanical bionic fish drive component structure mainly includes a base plate assembly, such as... Figure 1 , Figure 2 As shown, the substrate assembly is connected in sequence as follows: first substrate 28, second substrate 24, third substrate 20, and fourth substrate 16. Taking the connection between the first substrate 28 and the second substrate 24 as an example, as... Figure 4 As shown, the lower end of the first substrate 28 is provided with an internal gear ring 2802, and the lower right end of the first substrate is provided with a double-ear type boss 2805. The double-ear type boss is provided with a shaft 2806, which coincides with the center line of the pitch circle diameter of the internal gear ring 2802. The upper end of the second substrate 24 is provided with a 1 / 3 external gear 2401, and the gear shaft 2402 is provided with a left shoulder 2403 and a right shoulder 2404. The first substrate 28 and the second substrate 24 are connected by the upper 3 / 4 retaining ring 3101 and the lower 3 / 4 retaining ring 3104 of the first substrate connecting plate 31 through a hole-shaft engagement. The diameters of the upper cylindrical surface 3102 and the lower cylindrical surface 3103 of the first substrate connecting plate 31 are the same as the diameters of the shaft 2806 and the gear shaft 2402, and the thickness of the first substrate connecting plate 31 is the same as the distance between the two shoulders of the gear shaft 2402 and the length of the shaft 2806. At this time, the first substrate connecting plate 31 can rotate around the axis 2806, and its radial movement is restricted by the two lug surfaces of the double lug type boss 2805. The gear shaft 2402 of the second substrate 24 can rotate around the central axis of the lower 3 / 4 retaining ring 3104 of the first substrate connecting plate 31, and its radial movement is restricted by the two shoulders of the gear shaft 2402. The mounting method and mating relationship of the second substrate 24, the third substrate 20 and the fourth substrate 16 are the same as those between the first substrate 28 and the second substrate 24.

[0075] like Figure 2 , Figure 4 As shown, the upper end of the first substrate 28 is provided with a hinge boss 2803 containing a cylindrical hole 2804, which is hinged to the fish head 1 via a fish head pin 2. The lower end of the fish head is provided with a double-ear hinge boss 101 structure containing a cylindrical through hole 102. The two cylindrical holes have the same diameter, and the diameter of the cylindrical through hole 102 is the same as the diameter of the hinge cylindrical hole 2804 contained in the hinge boss 2803 at the upper end of the first substrate 28. The diameter of the fish head pin 2 is the same as the diameter of the two cylindrical holes of the double-ear hinge boss 101 at the lower end of the fish head 1, and it is inserted into the cylindrical through hole 102 and the hinge cylindrical hole 2804 by an interference fit. The fish head 1 and the first substrate 28 can rotate relative to each other, but movement in other degrees of freedom is restricted except for rotation.

[0076] like Figure 5As shown, the lower end of the fourth base plate 16 is provided with an external gear set 1601, the center of which includes a small gear shaft 1602. The small gear shaft 1602 and the large gear shaft 1605 are separated by a left shoulder 1603 and a right shoulder 1604. The fourth base plate 16 and the fish tail 14 are connected and engaged through the hole shaft of the fish tail connecting plate 15. The upper end of the fish tail 14 is provided with the same gear set 1601 structure as the fourth base plate 16, and its external gear module, number of teeth, and pitch circle diameter are all the same. The fish tail connecting plate 15 is provided with an upper 3 / 4 retaining ring 1501, the diameter of which is equal to the diameter of the small gear shaft 1602. The width of the fish tail connecting plate 15 is the same as the distance between the left shoulder 1604 and the right shoulder 1603. Therefore, the radial movement of the fish tail connecting plate 15 is restricted by the two shoulders, but it does not affect its rotation. The structure 1502 at the lower end of the fish tail connecting plate 15 is the same as the structure of the upper 3 / 4 retaining ring 1501, and is assembled onto the fish tail 14 in the same way. At this point, the connection between the base plate assembly, the fish tail 15, and the fish head 1 is completed.

[0077] Piezoelectric wafers are connected to opposite sides of the substrate assembly, such as... Figure 2 As shown, a first right piezoelectric chip 29 and a first left piezoelectric chip 30 are bonded to both sides of the first substrate 28 with epoxy resin adhesive; a second right piezoelectric chip 25 and a second left piezoelectric chip 26 are bonded to both sides of the second substrate 24 with epoxy resin adhesive; a third right piezoelectric chip 21 and a third left piezoelectric chip 22 are bonded to both sides of the third substrate 20 with epoxy resin adhesive; and a fourth right piezoelectric chip 17 and a fourth left piezoelectric chip 18 are bonded to both sides of the fourth substrate 16 with epoxy resin adhesive.

[0078] At this point, the internal drive components of the bionic fish have been connected. The connection between the external motion transmission components and the internal drive components is as follows: the connection between the fish body and the corresponding substrate, and the connection between the fish body assemblies. The fish body assembly includes a first fish body segment 3, a second fish body segment 6, a third fish body segment 10, and a fourth fish body segment 13. The substrate corresponding to the first fish body segment 3 is the first substrate 28, the substrate corresponding to the second fish body segment 6 is the second substrate 24, the substrate corresponding to the third fish body segment 10 is the third substrate 20, and the substrate corresponding to the fourth fish body segment 13 is the fourth substrate 16. The connection between the fish body assemblies is that the first fish body segment 3, the second fish body segment 6, the third fish body segment 10, and the fourth fish body segment 13 are connected sequentially.

[0079] like Figure 6As shown, the connection between the fish body and the corresponding substrate is exemplified by the connection between the first fish body segment 3 and the first substrate 28. The left end face of the first fish body segment 3 has a one-sided through hole 305, and the left end face of the first substrate 28 has a substrate through hole 2801. The first fish body segment 3 and the first substrate 28 are connected by a first fish body pin 4. The diameter of the first fish body pin 4, the one-sided through hole 305 of the first fish body segment 3, and the substrate through hole 2801 are the same. The first fish body pin 4 rigidly connects the first fish body segment 3 and the first substrate 28 through an interference fit, making them a rigid whole. The installation method and fitting relationship of the second fish body segment 6, the third fish body segment 10, and the fourth fish body segment 13 are the same as those between the first fish body segment 3 and the first substrate 28.

[0080] like Figure 7 As shown, the connections between the fish body assemblies are exemplified by the connection between the first fish body segment 3 and the second fish body segment 6. The lower end of the first fish body segment 3 is provided with a left double-ear-shaped protrusion 301 and a right double-ear-shaped protrusion 303, both with identical structures. Similarly, the upper end of the second fish body segment 6 is provided with a left double-ear-shaped protrusion 601 and a right double-ear-shaped protrusion 602, with structures identical to the two double-ear-shaped protrusions at the lower end of the first fish body segment 3. Taking the left double-ear-shaped protrusion 301 of the first fish body segment 3 as an example, it is equipped with a cylindrical shaft 302. The first segment of the fish body 3 is connected to the sixth connecting plate 27 via a 3 / 4 cylindrical hole 2701. The diameter of the 3 / 4 cylindrical hole 2701 of the sixth connecting plate 27 is the same as the diameter of the cylindrical shaft 302 of the left hanging ear boss 301, and the width of the sixth connecting plate 27 is the same as the distance between the two hanging ear surfaces 304 of the left hanging ear boss 301. Therefore, radial movement is restricted, but relative rotation is possible. The lower 3 / 4 cylindrical hole 2702 of the sixth connecting plate 27 is connected to the upper left double hanging ear boss 601 of the second segment of the fish body 6 in the same way. The lower right double hanging ear boss 303 of the first segment of the fish body 3 and the upper right hanging ear boss 602 of the second segment of the fish body 6 are connected to the first connecting plate 5 in the same way as the first segment of the fish body 3, the second segment of the fish body 6 with the left double hanging ear boss and the sixth connecting plate 27. The first fish body 3 and the second fish body 6 are connected by the first connecting plate 5 and the sixth connecting plate 27 hole shaft. The installation and connection methods of the second fish body 6, the third fish body 10 and the fourth fish body 13 are the same.

[0081] Taking the center point of the structure where the fish head is located as the current position (x1, y1) of the bionic fish, and the target point position as (x, y), the formula for calculating the required deflection angle θ is as follows:

[0082]

[0083] The biomimetic fish drive structure includes a first substrate 28, a second substrate 24, a third substrate 20, and a fourth substrate 16. The first substrate 28, the second substrate 24, and the third substrate 20 are biomimetic fish turning drive components, and the fourth substrate 16 is a biomimetic fish forward drive component. The fourth substrate 16 is connected to the fish tail 14 by means of external gear meshing, and the fish tail 14 serves as the motion transmission component of the forward drive component, the fourth substrate 16.

[0084] Let the driving voltage of the substrate be U, the deflection angle be θ, and the maximum driving voltage be U0. The formula for calculating the driving voltage is:

[0085]

[0086] When the first substrate 28, the second substrate 24, the third substrate 20, and the fourth substrate 16 are driven independently with a rated voltage U0, the deflection angle of each substrate is θmax.

[0087] Let the swimming speed of the bionic fish be v, the comprehensive coefficient be C, the tail swing amplitude be A, and the tail swing frequency be f. Then the formula for calculating the swimming speed of the bionic fish is v = C·Af. Where the fourth substrate is driven independently by the maximum driving voltage U0, the tail swing amplitude is Amax, and the swimming speed of the bionic fish is v0.

[0088] This embodiment also discloses a driving method for a piezoelectric chip-driven mechanical bionic fish. The driving method is used to achieve closed-loop position control of the mechanical bionic fish, including high-precision turning and forward control by controlling the substrate driving voltage U during the process of the bionic fish reaching the target position. Assuming that the first substrate 28, second substrate 24, third substrate 20, and fourth substrate 16 are all offset to the left, voltage excitation needs to be applied to the first right piezoelectric chip 29, second right piezoelectric chip 25, third right piezoelectric chip 21, and fourth right piezoelectric chip 17. The rated operating voltage of the first right piezoelectric chip 29, second right piezoelectric chip 25, third right piezoelectric chip 21, and fourth right piezoelectric chip 17 is U0. That is, when a voltage excitation of value U0 is applied to the first right piezoelectric chip 29, second left piezoelectric chip 25, third left piezoelectric chip 21, and fourth left piezoelectric chip 17, all of them reach their maximum deflection angle. Assuming the maximum horizontal deflection angle of the first substrate, second substrate, third substrate, and fourth substrate is θmax, the driving method is as follows:

[0089] Establish a two-dimensional rectangular coordinate system based on the current position coordinates of the bionic fish;

[0090] Obtain the target location coordinates (x, y);

[0091] Get the current position coordinates (x1, y1) of the bionic fish;

[0092] If x > 0 and y > 0, the turning angle is calculated as follows:

[0093]

[0094] If x < 0 and y > 0, the turning angle is calculated as follows:

[0095]

[0096] If x > 0 and y < 0, the turning angle is calculated as follows:

[0097]

[0098] If x < 0 and y < 0, the turning angle is calculated as follows:

[0099]

[0100] If the turning angle θ > 0.1°, then all the piezoelectric chips on the driving substrate that need to turn are right piezoelectric chips, such as the first right piezoelectric chip 29, the second right piezoelectric chip 25, and the third right piezoelectric chip 21. The forward driving substrate is the fourth substrate 16, and its driving voltage excitation method is that the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 are excited by mutual exchange.

[0101] If the turning angle θ < -0.1°, then all the piezoelectric chips on the driving substrate that need to turn are left piezoelectric chips, such as the first left piezoelectric chip 30, the second left piezoelectric chip 24, and the third left piezoelectric chip 22. The forward driving substrate is the fourth substrate 16, and its driving voltage excitation method is that the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 exchange excitation.

[0102] In some feasible embodiments, a controller is used to execute the above driving method:

[0103] Step 1: Obtain the target's position coordinates (x, y).

[0104] Step 2: Input the current position coordinates (x1, y1) of the bionic fish.

[0105] Step 3: Calculate the corresponding turning angle θ based on the target coordinate position and the bionic fish coordinate position.

[0106] Step 4: Determine whether the bionic fish needs to turn based on the calculated required turning angle θ value.

[0107] If the turning angle |θ| ≥ 0.1°, the bionic fish needs to turn, and then proceed to step 5.

[0108] If the turning angle |θ| < 0.1°, the bionic fish does not need to turn and proceeds directly to step 17.

[0109] Step 5: Determine whether |θ| is less than or equal to 20°.

[0110] If |θ| is less than or equal to 20°, proceed directly to step 9.

[0111] If |θ| is greater than 20°, proceed directly to step 6.

[0112] Step 6: The first substrate 28, the second substrate 24, and the third substrate 20 all need to be excited by voltage U0, and the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be excited by driving voltage U0 interchangeably.

[0113] If θ is positive, then excitation voltage U0 is applied to the first left piezoelectric chip 30, the second left piezoelectric chip 24, and the third left piezoelectric chip 22, while the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be excited by excitation voltage U0 applied alternately.

[0114] If θ is negative, then excitation voltage U0 is applied to the first right piezoelectric chip 29, the second right piezoelectric chip 25, and the third right piezoelectric chip 21, while the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be excited by excitation voltage U0 applied alternately.

[0115] Step 7: Obtain the new current position coordinates (x3, y3) of the bionic fish.

[0116] Step 8, return to step 2.

[0117] Step 9: Determine which range the turning angle θ falls within.

[0118] If 1°≤|θ|≤5°, then proceed to step 10.

[0119] If 5° < |θ| ≤ 10θ, then proceed to step 12.

[0120] If 10° < |θ| ≤ 20°, then proceed to step 14.

[0121] Step 10: The first substrate 28 needs to be stimulated with a voltage of 0.25U0, while the second substrate 24 and the third substrate 20 do not require voltage stimulation. The fourth substrate 16 is provided with the...

[0122]

[0123] The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 need to be driven by an applied driving voltage of 0.25U0.

[0124] If θ is positive, a voltage of 0.25U0 is applied to the first left piezoelectric chip 30 for excitation, while the second left piezoelectric chip 24 and the third left piezoelectric chip 22 are not applied with excitation voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be applied with excitation voltage of 0.25U0 respectively.

[0125] If θ is negative, a voltage of 0.25U0 is applied to the first right piezoelectric chip 29 for excitation, while the second right piezoelectric chip 25 and the third right piezoelectric chip 21 are not excitation voltages applied. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be excitation voltages of 0.25U0 applied interchangeably.

[0126] Step 11, proceed directly to step 15.

[0127] In step 12, the first substrate 28 needs to be stimulated with a voltage of 0.5U0, the second substrate 24 and the third substrate 20 do not need to be stimulated with voltage, and the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be stimulated with a driving voltage of 0.25U0.

[0128] If θ is positive, a voltage of 0.5U0 is applied to the first left piezoelectric chip 30 for excitation, while the second left piezoelectric chip 24 and the third left piezoelectric chip 22 are not applied with excitation voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be applied with an excitation voltage of 0.25U0.

[0129] If θ is negative, a voltage of 0.5U0 is applied to the first right piezoelectric chip 29, and no excitation voltage is applied to the second right piezoelectric chip 25 and the third right piezoelectric chip 21. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate 4 substrate 16 need to be driven by an excitation voltage of 0.25U0.

[0130] Step 13, proceed directly to step 15.

[0131] In step 14, the first substrate 28 needs to be stimulated by voltage U0, while the second substrate 24 and the third substrate 20 do not need to be stimulated by voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be stimulated by driving voltage 0.25U0 interchangeably.

[0132] If the value of θ is positive, a voltage U0 is applied to the first left piezoelectric chip 30 for excitation, while the second left piezoelectric chip 24 and the third left piezoelectric chip 22 are not applied with excitation voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be applied with an excitation voltage of 0.25U0.

[0133] If θ is negative, then voltage U0 is applied to the first right piezoelectric chip 29, and no excitation voltage is applied to the second right piezoelectric chip 25 and the third right piezoelectric chip 21. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate 4 substrate 16 need to be driven by an excitation voltage of 0.25U0.

[0134] Step 15: Obtain the new current position coordinates (x2, y2) of the bionic fish.

[0135] Step 16, return to step 2.

[0136] Step 17: Calculate the distance Length between the current coordinates (x1, y1) and the target coordinates (x, y) of the bionic fish.

[0137]

[0138] Step 18: Determine if the Length value is less than or equal to 1.

[0139] If Length > 1, the bionic fish needs to move forward, and then proceed to step 19.

[0140] If Length≤1, the bionic fish does not need to move forward and can directly proceed to step 22.

[0141] In step 19, the first substrate 28, the second substrate 24, and the third substrate 20 do not require voltage excitation, while the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be driven by the driving voltage kU0.

[0142] Step 20: Obtain the new current position coordinates (x4, y4) of the bionic fish.

[0143] Step 21, return to step 2.

[0144] Step 22: Execute the end command.

[0145] Preferably, this embodiment discloses a bionic fish based on piezoelectric dual-chip drive and its motion control method. The motion control method is used to realize the closed-loop position control of the bionic fish, which can realize real-time tracking of the position of the bionic fish and accurately correct its turning angle. Through continuous correction, the precise control of the position of the bionic fish can be achieved.

[0146] The following is based on the appendix Figure 9 For example, the movement process of the bionic fish at different target position coordinates (x, y) is illustrated:

[0147] Example 1: When the target point's coordinates are (50, 50).

[0148] Step 1: Obtain the target coordinates (50, 50).

[0149] Step 2: Input the current coordinates of the bionic fish (0,0).

[0150] Step 3: Calculate the corresponding turning angle |θ|, which is 45°.

[0151] Step 4: Determine whether the bionic fish needs to turn based on the calculated required turning angle θ value.

[0152] If the turning angle |θ| ≥ 0.1°, the bionic fish needs to turn, and then proceed to step 5.

[0153] If the turning angle |θ| < 0.1°, the bionic fish does not need to turn and proceeds directly to step 17.

[0154] If the result indicates that the bionic fish needs to turn, proceed to step 5.

[0155] Step 5: Determine whether |θ| is less than or equal to 20°.

[0156] If |θ| is less than or equal to 20°, proceed directly to step 9.

[0157] If |θ| is greater than 20°, proceed directly to step 6.

[0158] If the result is that |θ| is greater than 20°, then proceed directly to step 6.

[0159] Step 6: The first substrate 28, the second substrate 24, and the third substrate 20 all need to be excited by voltage U0, and the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be excited by driving voltage U0 interchangeably.

[0160] If θ is positive, then excitation voltage U0 is applied to the first left piezoelectric chip 30, the second left piezoelectric chip 24, and the third left piezoelectric chip 22, while the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be excited by excitation voltage U0 applied alternately.

[0161] If θ is negative, then excitation voltage U0 is applied to the first right piezoelectric chip 29, the second right piezoelectric chip 25, and the third right piezoelectric chip 21, while the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be excited by excitation voltage U0 applied alternately.

[0162] Step 7: Obtain the new current position coordinates (x3, y3) of the bionic fish.

[0163] Step 8, return to step 2.

[0164] Step 9: Determine which range the turning angle θ falls within.

[0165] If 1°≤|θ|≤5°, then proceed to step 10.

[0166] If 5° < |θ| ≤ 10°, proceed to step 12.

[0167] If 10° < |θ| ≤ 20°, then proceed to step 14.

[0168] Step 10: The first substrate 28 needs to be stimulated with a voltage of 0.25U0. The second substrate 24 and the third substrate 20 do not need to be stimulated with a voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be stimulated with a driving voltage of 0.25U0.

[0169] If θ is positive, a voltage of 0.25U0 is applied to the first left piezoelectric chip 30 for excitation, while the second left piezoelectric chip 24 and the third left piezoelectric chip 22 are not applied with excitation voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be applied with excitation voltage of 0.25U0 respectively.

[0170] If θ is negative, a voltage of 0.25U0 is applied to the first right piezoelectric chip 29 for excitation, while the second right piezoelectric chip 25 and the third right piezoelectric chip 21 are not excitation voltages applied. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be excitation voltages of 0.25U0 applied interchangeably.

[0171] Step 11, proceed directly to step 15.

[0172] In step 12, the first substrate 28 needs to be stimulated with a voltage of 0.5U0, the second substrate 24 and the third substrate 20 do not need to be stimulated with voltage, and the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be stimulated with a driving voltage of 0.25U0.

[0173] If θ is positive, a voltage of 0.5U0 is applied to the first left piezoelectric chip 30 for excitation, while the second left piezoelectric chip 24 and the third left piezoelectric chip 22 are not applied with excitation voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be applied with an excitation voltage of 0.25U0.

[0174] If θ is negative, a voltage of 0.5U0 is applied to the first right piezoelectric chip 29, and no excitation voltage is applied to the second right piezoelectric chip 25 and the third right piezoelectric chip 21. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate 4 substrate 16 need to be driven by an excitation voltage of 0.25U0.

[0175] Step 13, proceed directly to step 15.

[0176] In step 14, the first substrate 28 needs to be stimulated by voltage U0, while the second substrate 24 and the third substrate 20 do not need to be stimulated by voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be stimulated by driving voltage 0.25U0 interchangeably.

[0177] If the value of θ is positive, a voltage U0 is applied to the first left piezoelectric chip 30 for excitation, while the second left piezoelectric chip 24 and the third left piezoelectric chip 22 are not applied with excitation voltage. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate fourth substrate 16 need to be applied with an excitation voltage of 0.25U0.

[0178] If θ is negative, then voltage U0 is applied to the first right piezoelectric chip 29, and no excitation voltage is applied to the second right piezoelectric chip 25 and the third right piezoelectric chip 21. The fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the forward drive substrate 4 substrate 16 need to be driven by an excitation voltage of 0.25U0.

[0179] Step 15: Obtain the new current position coordinates (x2, y2) of the bionic fish.

[0180] Step 16, return to step 2.

[0181] Step 17: Calculate the distance Length between the current position coordinates (x1, y1) and the target position coordinates (50, 50) of the bionic fish.

[0182]

[0183] Step 18: Determine if the Length value is less than or equal to 1.

[0184] If Length > 1, the bionic fish needs to move forward, and then proceed to step 19.

[0185] If Length≤1, the bionic fish does not need to move forward and can directly proceed to step 22.

[0186] In step 19, the first substrate 28, the second substrate 24, and the third substrate 20 do not require voltage excitation, while the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be driven by the driving voltage kU0.

[0187] Step 20: Obtain the new current position coordinates (x4, y4) of the bionic fish.

[0188] Step 21, return to step 2.

[0189] Step 22: The bionic fish is now in place.

[0190] Example 2: When the target point's coordinates are (0, 50).

[0191] Step 1: Obtain the target coordinates (0, 50).

[0192] Step 2: Input the current coordinates of the bionic fish (0,0).

[0193] Step 3: Calculate the corresponding turning angle |θ|, which is 0°.

[0194] Step 4: Determine whether the bionic fish needs to turn based on the calculated required turning angle θ. If the turning angle |θ| < 0.1°, the bionic fish does not need to turn.

[0195] Step 5: Calculate the distance Length between the current position coordinates (x1, y1) and the target position coordinates (0, 50) of the bionic fish.

[0196]

[0197] Step 6: Determine if the Length value is less than or equal to 1.

[0198] If Length > 1, the bionic fish needs to move forward, and then proceed to step 7.

[0199] If Length≤1, the bionic fish does not need to move forward and can directly proceed to step 10.

[0200] In step 7, the first substrate 28, the second substrate 24, and the third substrate 20 do not require voltage excitation, while the fourth left piezoelectric chip 18 and the fourth right piezoelectric chip 17 on the fourth substrate 16 need to be driven by the driving voltage kU0.

[0201] Step 8: Obtain the new current position coordinates (x4, y4) of the bionic fish.

[0202] Step 9, return to step 2.

[0203] Step 10: The bionic fish is now in place.

[0204] Combining the above-described horizontal offset embodiments with Figure 9 It can be seen that the driving method proposed in this invention can determine whether to enter the fast, large-angle turning driving mode based on the input target position coordinates. When the turning angle is reduced to a small-angle, high-precision turning driving mode, the turning angle is precisely corrected. Compared with traditional bionic fish, this invention is equivalent to segmenting the turning driving component of the fish body, which can achieve higher turning angle control accuracy. At the same time, among various driving schemes that meet the conditions, the base plate action with higher turning and forward accuracy is preferentially selected, which can improve the position closed-loop control accuracy of the bionic fish.

[0205] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by writing a computer program into relevant hardware, and the program can be stored in a readable storage medium on the hardware. The readable storage medium includes, but is not limited to, memory with storage and memory functions such as a microcontroller.

[0206] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A biomimetic fish driven by a piezoelectric chip, characterized in that, include: Fish head; The driving component includes a turning driving component and a forward driving component. The turning driving component is connected to the fish head. The turning driving component includes three segmented base plates connected in sequence. The forward driving component includes one base plate. The three base plates of the turning driving component and the one base plate of the forward driving component are connected in sequence to form a base plate group. Each base plate is provided with a piezoelectric crystal. Among the four base plates connected in sequence in the base plate group, starting from the one closest to the fish head, the base plates are arranged in order as a first base plate, a second base plate, a third base plate, and a fourth base plate. The connection between two adjacent base plates is a gear ring and an external gear meshing connection. The lower end of the first base plate is provided with a gear ring and a double-ear type boss connector. The upper end of the second base plate is provided with an external gear and a gear shaft connector. They are rotatably connected by a first connecting plate. The connection methods between the second substrate and the third substrate, and between the third substrate and the fourth substrate, are the same as those between the first substrate and the second substrate. Each connected substrate can rotate relative to the other through its own connector and external connector. The piezoelectric wafer is disposed on opposite sides of the substrate. The piezoelectric wafer is connected to a wire. Applying a DC voltage to the piezoelectric wafer can deflect the substrate connected to the piezoelectric wafer. A motion transmission component, comprising a fish body assembly and a fish tail, wherein the fish body assembly is rigidly connected to a corresponding drive component, and the fish tail is connected to the forward drive component; The fish body assembly comprises four fish body segments connected in sequence. The connection method between adjacent fish body segments is the same. The lower end of the first fish body segment is provided with a first lower connector, and the upper end of the second fish body segment is provided with a second upper connector. The two are hinged by external connectors and can rotate relative to each other. The connection method between the second fish body segment and the third fish body segment, and between the third fish body segment and the fourth fish body segment, is the same as the connection method between the first fish body segment and the second fish body segment. The fish body assembly and the base plate assembly are connected accordingly, with each segment of the fish body and its corresponding base plate being connected by an interference fit with pins, making the two a rigid whole, and the deflection of the corresponding base plate is transmitted to the corresponding fish body in the same deflection state; The fourth base plate is connected to the fish tail by an external gear meshing connection. The lower end of the fourth base plate is provided with an external gear set, and the upper end of the fish tail is provided with the same internal gear set. The two can be connected by a fish tail connecting plate and rotate relative to each other to realize the forward drive of the bionic fish.

2. The piezoelectric chip-driven bionic fish according to claim 1, characterized in that, The first base plate of the turning drive component is connected to the fish head of the bionic fish-shaped structural component by a pin hinge. The first substrate has a hinge boss at the upper end and a double-ear boss at the lower end of the fish head. The two are hinged by the fish head pin and can rotate relative to each other.

3. A control method for a piezoelectric chip-driven bionic fish according to any one of claims 1-2, characterized in that, Includes the following steps: (a) Autonomous Motion Type Selection Control: Obtain the target position coordinates (x, y) and the current position coordinates (x1, y1) of the bionic fish, and calculate the turning angle θ based on the deviation: If |θ|≥0.1°, proceed to step (b); If |θ| < 0.1°, proceed to step (c); (b) Motion attitude accuracy control: Apply graded voltage excitation according to the range of |θ|: When |θ|>20°, the full voltage U0 is applied to the left / right piezoelectric wafers of the first, second, and third substrates, and the left / right piezoelectric wafers of the fourth substrate are applied U0 interchangeably. When |θ|≤20°: If 0° < |θ| ≤ 5°, apply 0.25 U0 to the left / right piezoelectric wafers of the first substrate; If 5° < |θ| ≤ 15°, apply 0.5 U0 to the left / right piezoelectric wafers of the first substrate; If 15° < |θ| ≤ 20°, U0 is applied to the left / right piezoelectric wafers of the first substrate; The second and third substrates are not excited, and the left and right piezoelectric wafers of the fourth substrate are alternately applied with 0.25 U0; (c) Forward speed precision control: Based on the distance between the current position and the target position, adjust the driving voltage of the left / right piezoelectric wafers of the fourth substrate to kU0,0. <k≤1; (d) Closed-loop feedback: Update the current position coordinates and return to step (a) until the target position is reached.

4. The control method for a piezoelectric chip-driven bionic fish according to claim 3, characterized in that, The autonomous selection control of motion type includes the following steps: Step 1: Obtain the target's position coordinates (x, y); Step 2: Input the current coordinates (x1, y1) of the bionic fish; Step 3: Calculate the corresponding turning angle θ based on the target coordinate position and the bionic fish coordinate position; Step 4: Determine whether the bionic fish needs to turn based on the calculated required turning angle θ. If the turning angle |θ| ≥ 0.1°, the bionic fish needs to turn, then proceed to step 5; If the turning angle |θ| < 0.1°, the bionic fish does not need to turn and proceeds directly to step 17.

5. The control method for a piezoelectric chip-driven bionic fish according to claim 3, characterized in that, The motion posture accuracy control includes the following steps: Step 5: Determine if |θ| is less than or equal to 20°; If |θ| is less than or equal to 20°, proceed directly to step 9; If |θ| is greater than 20°, proceed directly to step 6; Step 6: Voltage U0 needs to be applied to the first substrate, the second substrate, and the third substrate. The fourth left piezoelectric chip and the fourth right piezoelectric chip on the fourth substrate need to be driven by the same voltage U0. If the value of θ is positive, then the excitation voltage U0 is applied to the first left piezoelectric chip, the second left piezoelectric chip, and the third left piezoelectric chip, while the fourth left piezoelectric chip and the fourth right piezoelectric chip on the forward driving substrate need to be excited by excitation voltage U0 applied interchangeably. If θ is negative, then excitation voltage U0 is applied to the first right piezoelectric chip, the second right piezoelectric chip, and the third right piezoelectric chip, while the fourth left piezoelectric chip and the fourth right piezoelectric chip on the forward driving substrate need to be excited by excitation voltage U0 applied interchangeably. Step 7: Obtain the new current position coordinates (x3, y3) of the bionic fish; Step 8, return to step 2; Step 9: Determine which range the turning angle θ falls within; If 1°≤|θ|≤5°, proceed to step 10; If 5° < |θ| ≤ 10°, proceed to step 12; If 10° < |θ| ≤ 20°, then proceed to step 14; Step 10: The first substrate needs to be stimulated with a voltage of 0.25 U0. The second and third substrates do not need to be stimulated with a voltage. The fourth left piezoelectric chip and the fourth right piezoelectric chip on the fourth substrate need to be stimulated with a driving voltage of 0.25 U0. If the value of θ is positive, a voltage of 0.25 U0 is applied to the first left piezoelectric chip for excitation, while no excitation voltage is applied to the second and third left piezoelectric chips. The fourth left piezoelectric chip and the fourth right piezoelectric chip on the forward driving substrate need to be driven by the same voltage of 0.25 U0. If θ is negative, a voltage of 0.25 U0 is applied to the first right piezoelectric chip for excitation, while no excitation voltage is applied to the second and third right piezoelectric chips. The fourth left and fourth right piezoelectric chips on the forward driving substrate need to be driven by the same voltage of 0.25 U0. Step 11, proceed directly to step 15; Step 12: The first substrate needs to be stimulated with a voltage of 0.5 U0. The second and third substrates do not need to be stimulated with a voltage. The fourth left piezoelectric chip and the fourth right piezoelectric chip on the fourth substrate need to be stimulated with a driving voltage of 0.25 U0. If θ is positive, a voltage of 0.5 U0 is applied to the first left piezoelectric chip for excitation, while no excitation voltage is applied to the second and third left piezoelectric chips. The fourth left and fourth right piezoelectric chips on the forward driving substrate need to be driven by an excitation voltage of 0.25 U0. If the value of θ is negative, a voltage of 0.5 U0 is applied to the first right piezoelectric chip for excitation, while no excitation voltage is applied to the second and third right piezoelectric chips. The fourth left and fourth right piezoelectric chips on the forward driving substrate need to be driven by an excitation voltage of 0.25 U0. Step 13, proceed directly to step 15; Step 14: The first substrate needs to be stimulated by voltage U0, while the second and third substrates do not need to be stimulated by voltage. The fourth left piezoelectric chip and the fourth right piezoelectric chip on the fourth substrate need to be stimulated by driving voltage 0.25 U0 interchangeably. If θ is positive, a voltage U0 is applied to the first left piezoelectric chip, while no excitation voltage is applied to the second and third left piezoelectric chips. The fourth left and fourth right piezoelectric chips on the forward driving substrate need to be driven by an excitation voltage of 0.25 U0. If θ is negative, then voltage U0 is applied to the first right piezoelectric chip, and no excitation voltage is applied to the second and third right piezoelectric chips. The fourth left and fourth right piezoelectric chips on the forward driving substrate need to be driven by an excitation voltage of 0.25 U0. Step 15: Obtain the new current position coordinates (x2, y2) of the bionic fish; Step 16, return to step 2.

6. The control method for a piezoelectric chip-driven bionic fish according to claim 3, characterized in that, The forward speed precision control includes the following steps: Step 17: Calculate the distance Length between the current coordinates (x1, y1) and the target coordinates (x, y) of the bionic fish. Step 18: Determine if the Length value is less than or equal to 1; If Length > 1, the bionic fish needs to move forward, and then proceed to step 19; If Length≤1, the bionic fish does not need to move forward and can directly proceed to step 22; Step 19: No voltage excitation is required for the first substrate, the second substrate, and the third substrate. The fourth left piezoelectric chip and the fourth right piezoelectric chip on the fourth substrate need to be driven by the driving voltage kU0 interchangeably. Step 20: Obtain the new current position coordinates (x4, y4) of the bionic fish; Step 21, return to step 2; Step 22: Execute the end command.

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