Bionic robotic fish based on magnetic force driving and propelling method thereof

Abstract

The invention discloses a bionic robotic fish based on magnetic driving and a propelling method thereof, and relates to the technical field of fish bionics, the bionic robotic fish is composed of a bionic fish body, a magnetic driving device and a fish tail, and the magnetic driving device drives the fish tail to swing back and forth to propel the fish body to advance; according to the magnetic driving device, the magnetic field direction of the electromagnetic module is periodically changed through the control module, the magnetic driving device interacts with the permanent magnet module to generate torque, the swing module and the fishtail are driven to perform efficient and smooth reciprocating motion, and the driving mode is simple in structure and higher in reliability, durability and maintainability; the crescent-shaped structure of the fish tail simulates the swimming mechanism of real fishes, strong propulsive force is provided, and the bionic fish body is completed according to bionics, so that the bionic fish body has excellent adaptive capacity and flexible movement performance in complex submarine topography and high-current environment, and can easily pass through narrow space or execute fine operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fish bionics, in particular to a bionic robotic fish based on magnetic driving and a propulsion method thereof. BACKGROUND

[0002] In recent years, China's marine industry as a whole has shown rapid growth, and related economic activities have been continuously improved. Although the increasing uncertainty factors at home and abroad have formed a complex and changeable environment, bringing certain pressure to China's marine economy, with the implementation of a number of support policies and the continuous improvement of technological level, the marine economy has gradually shown strong development resilience. According to the development status of each traditional department, China's marine traditional industries cover marine fisheries, marine transportation and coastal tourism, etc. main parts, continue to occupy an important position in the structure of marine economy, and are expected to continue to maintain stable growth momentum in the future. With the increasingly fierce competition in the field of oceans among countries around the world, the ability to obtain marine information and the level of exploitation and utilization of marine resources have become the focus of attention. Under this background, underwater robots, as a technology that combines advanced technology and relative cost advantage, can replace human beings to dive deeper and farther into the sea, and perform high-difficulty tasks such as environmental monitoring, resource exploration, equipment maintenance and scientific research. It has become a key technical support for promoting marine development.

[0003] At present, traditional underwater robots mainly rely on propellers and rudder surfaces for propulsion and control, have the advantages of strong load capacity, large operating depth, and long underwater work time, and play an important role in fish monitoring, submarine pipeline inspection, and large-scale topographic mapping. The Chinese patent application with the application number 202411658721.1 discloses a high-current-resistant multi-point observation type fish school monitoring underwater robot based on multi-source data fusion. The robot is equipped with four vector thrusters around the shell to form an adaptive ocean current resistance system and a multi-sensor fusion technology, which can maintain stability in complex water flow. At the same time, the robot uses a cluster of underwater robots based on deep learning algorithm for fish school identification, greatly improving the accuracy and efficiency of fish tracking. In addition, the integrated ocean current-solar energy system enables the underwater robot to have long endurance, suitable for long-distance and long-time operation. However, the robot still has obvious limitations: first, the mechanical propulsion system of the vector thruster has a large noise, which easily disturbs marine life and is not conducive to covert operations; second, its structure design limits its maneuverability, especially in complex seabed topography or strong current environment; third, the energy utilization efficiency is low, the underwater robot has a large resistance in shape design, solar energy cannot be used in deep water, which restricts its continuous operation time; in addition, its operation ability is often insufficient when facing narrow spaces or tasks requiring delicate operations.

[0004] To overcome the above bottleneck, further improve the environmental adaptability, operation efficiency and concealment of underwater robots, bionic robot technology gradually attracts attention. By imitating the swimming mechanism and shape structure of marine organisms such as fish, cephalopods and other marine organisms, bionic underwater robots are expected to significantly reduce noise, improve maneuverability and energy efficiency, so as to be more suitable for performing long-term, high-precision tasks in sensitive ecological areas and complex hydrological environments, and become an important direction of the next generation of ocean exploration and development. SUMMARY

[0005] The application provides a bionic robotic fish based on magnetic drive and a propulsion method thereof, which has good environmental adaptability and concealment by adopting bionic shape and bionic movement mode, and can significantly reduce noise, improve maneuverability and energy efficiency.

[0006] To solve the above technical problems, the technical scheme provided by the application is as follows: In a first aspect, the application provides a bionic robotic fish based on magnetic drive, comprising: a bionic fish body, a magnetic drive device and a fish tail. The cross section perpendicular to the main axis of the bionic fish body is elliptical, and the longitudinal section is approximately parabolic spindle-shaped. The bionic fish body comprises an upper shell and a lower shell, which are spliced to form a hollow bionic fish body. A sealing structure is arranged between the upper shell and the lower shell. The magnetic drive device is installed in the hollow bionic fish body. The magnetic drive device is provided with a permanent magnet module, an electromagnetic module, a control module and a swing module. The control module receives external instructions to power the electromagnetic module and controls the electromagnetic module to periodically generate opposite direction magnetic fields. The magnetic force between the permanent magnet module and the electromagnetic module forms a torque to drive the swing module to reciprocate. The swing module is connected to the fish tail. The fish tail comprises a tail handle and a tail fin. The tail handle is curved near one end of the bionic fish body. The tail fin is crescent-shaped.

[0007] Further, the sealing structure comprises a ring-shaped sealing groove, a waterproof rubber strip and a fastening unit. The ring-shaped sealing groove is arranged at the connection between the upper shell and the lower shell. The waterproof rubber strip is installed in the ring-shaped sealing groove and is compressed by the upper shell and the lower shell. The fastening unit is used to connect and fix the upper shell and the lower shell.

[0008] Further, the bionic fish body is externally provided with pectoral fins, abdominal fins and dorsal fins. The pectoral fins, abdominal fins and dorsal fins are arranged in a cross rudder manner. The length of the abdominal fin is consistent with that of the dorsal fin.

[0009] Further, the cross-sectional length of the bionic fish body is greater than that of the fish tail. The length of the fish tail is 1 / 2 to 1 / 3 of the total length of the bionic robotic fish.

[0010] Further, the magnetic drive device is provided with a splitable shell, the split position of the shell is provided with a groove, the inside of the shell is provided with a rotating disc at the central axis, the permanent magnet module is a four-segment fan-shaped magnet, the four-segment fan-shaped magnet is installed on the rotating disc in a counterclockwise direction according to the SN-NS or NS-SN magnetic pole sequence, the rotating disc is provided with a rotating shaft at the central axis, the rotating shaft is installed at the top and bottom of the shell respectively, the inside of the shell is provided with a fixed hole and a wire hole at intervals of 90°, the electromagnetic module is composed of a stator core and a coil wound on the stator core, the stator core is provided with a spline at the bottom, the spline is fixed on the fixed hole, the two ends of the coil are led out of the shell through the wire hole and connected to the control module, and the electromagnetic module and the permanent magnet module are located at the same horizontal height.

[0011] Further, the swing module is hinged at the edge of the rotating disc, the swing module is a swing rod, one end of the swing rod is hinged at the edge of the rotating disc through a stepped pin, the swing rod passes through the groove of the shell of the magnetic drive device, the middle part of the swing rod is provided with a notch, the bionic fish body is provided with a limiting column, the notch and the limiting column are matched and installed to limit the limit position of the swing of the two ends of the swing rod, and when the rotating disc is driven to rotate by the magnetic force, the central position of the fan-shaped magnet and the central axis of the corresponding electromagnetic module always maintain a certain included angle.

[0012] Further, the middle part of the tail handle and the tail fin is provided with a through hole, the swing rod passes through the through hole after passing through the bionic fish body to connect the tail handle and the tail fin, and the swing rod has elasticity.

[0013] In the second aspect, the application provides a bionic robotic fish propulsion method based on magnetic drive, comprising: S1, the control module receives external instructions, initializes the magnetic drive device, and resets the swing rod to be collinear with the main shaft of the bionic fish body; S2, propulsion execution, the control module controls the electromagnetic module to periodically generate magnetic fields in different directions, and the magnetic force between the electromagnetic module and the permanent magnet module forms a torque to drive the swing module to reciprocating swing; S3, the swing module drives the tail handle and the tail fin to reciprocating swing in opposite directions, and drives the bionic fish body to move forward.

[0014] In S1, when the swing rod is reset to be collinear with the main shaft of the bionic fish body, the initial swing of the swing module is set to right swing, the fan-shaped magnet at the hinge of the swing rod is the first fan-shaped magnet, the central line position of the first fan-shaped magnet and the central axis of a certain electromagnetic module are adjusted to maintain a right deflection included angle, the electromagnetic module is the first electromagnetic module, the other electromagnetic modules arranged counterclockwise are the second electromagnetic module, the third electromagnetic module and the fourth electromagnetic module, and the corresponding fan-shaped magnets are the second fan-shaped magnet, the third fan-shaped magnet and the fourth fan-shaped magnet.

[0015] In S2, if the S pole of the first sector-shaped magnet is on the left and the N pole is on the right, the magnetic induction line direction outside the first sector-shaped magnet is from N to S, the control module controls the first electromagnetic module to generate a magnetic field, the internal magnetic induction line of the stator core of the first electromagnetic module is from outside to inside, the external magnetic induction line is from inside to outside, the control module controls the second electromagnetic module on the right side of the first sector-shaped magnet to generate a magnetic field, the internal magnetic induction line of the stator core of the second electromagnetic module is from inside to outside, the external magnetic induction line is from outside to inside, since a right deflection angle is kept between the center line of the first sector-shaped magnet and the central axis of the first electromagnetic module, the magnetic induction line direction outside the first sector-shaped magnet is opposite to the magnetic induction line direction of the first electromagnetic module close to the first sector-shaped magnet, the first sector-shaped magnet is pushed to rotate counterclockwise, similarly, a right deflection angle is kept between the center line of the second sector-shaped magnet and the central axis of the second electromagnetic module, the second electromagnetic module pushes the second sector-shaped magnet to rotate counterclockwise, similarly, the other two electromagnetic modules push the corresponding sector-shaped magnets, so that the rotating disc rotates counterclockwise, and the swing module swings to the right; when the swing module swings to the right to the limit position, the control module changes the current direction of each electromagnetic module, so as to control the rotating disc to rotate clockwise, the swing module swings to the left, and reciprocating swing is realized.

[0016] The present application has the following beneficial effects due to the above technical scheme: The bionic fish body and fish tail structure design of the present application are completed according to bionics, so that the bionic fish body and fish tail have excellent adaptability and flexible motion performance in complex seabed topography and strong current environment, can easily pass through narrow space or perform fine operation; the magnetic force is used for driving, mechanical wear is reduced, interference of a traditional propeller on marine organisms is avoided, and the bionic fish body and fish tail are particularly suitable for concealed operation in a sensitive ecological area, noise generated in the operation process is extremely low, the magnetic driving device periodically changes the magnetic field direction of the electromagnetic module through the control module, interacts with the permanent magnet module to generate torque, drives the swing module and the fish tail to perform efficient and smooth reciprocating motion, the driving mode is not only simple in structure, but also high in reliability, durability and maintainability; the crescent structure of the fish tail simulates the swimming mechanism of real fish, provides strong propelling force, meanwhile, the sealing structure ensures the waterproof safety of underwater operation, and the cross rudder arrangement of the pectoral fin, pelvic fin and dorsal fin enhances the stability and control precision of the robotic fish; through these technical means, the robotic fish can perform long-term and high-precision tasks. BRIEF DESCRIPTION OF DRAWINGS

[0017] The drawings described herein are used to provide further understanding of the present application, constitute a part of the present application, and do not constitute improper limitations on the present application, and in the drawings: Figure 1 It is a schematic diagram of the bionic robotic fish structure of the present application; Figure 2 It is a schematic diagram of part of the bionic robotic fish structure of the present application; Figure 3Fig. 1 is a schematic diagram of a fish tail structure of a bionic fish robot according to the present application; Figure 4 Fig. 2 is a schematic diagram of a lower shell of a bionic fish body according to the present application; Figure 5 Fig. 3 is a schematic diagram of a magnetic driving device structure according to the present application; Figure 6 Fig. 4 is a schematic diagram of a partial structure of a magnetic driving device according to the present application; Figure 7 Fig. 5 is a top view of a partial structure of a magnetic driving device according to the present application; Figure 8 Fig. 6 is a flow chart of a bionic fish robot propulsion method according to the present application.

[0018] In the figure: 1-bionic fish body; 11-upper shell; 12-lower shell; 13-sealing structure; 131-annular sealing groove; 132-waterproof rubber strip; 133-fastening unit; 14-pectoral fin; 15-abdominal fin; 16-dorsal fin; 17-limiting column; 2-magnetic driving device; 21-permanent magnet module; 211-first sector magnet; 212-second sector magnet; 213-third sector magnet; 214-fourth sector magnet; 22-electromagnetic module; 221-stator core; 222-coil; 223-spline; 22A-first electromagnetic module; 22B-second electromagnetic module; 22C-third electromagnetic module; 22B-fourth electromagnetic module; 23-control module; 24-oscillating module; 241-step pin; 242-notch; 25-shell; 251-groove; 252-fixing hole; 253-thread hole; 26-rotating disc; 261-rotating shaft; 3-fish tail; 31-caudal peduncle; 32-caudal fin; 33-through hole. DETAILED DESCRIPTION

[0019] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments, which are used to explain the present application but not to limit the present application.

[0020] In the present embodiment, a rectangular coordinate system is established, with the head direction of the bionic fish body as the Y axis to define the fish tail oscillation direction; the internal magnetic induction lines of the stator core are defined to be from inside to outside, with the end close to the permanent magnet module as the inside and the end close to the inner wall of the shell as the outside.

[0021] Referring to Fig. 1, Figures 1-3 the present embodiment provides a magnetic force driving based bionic fish robot, which comprises a bionic fish body 1, a magnetic driving device 2, and a fish tail 3. The bionic fish body 1 has an elliptical cross section perpendicular to the main body axis and a spindle shape approximate to a parabola in the longitudinal section, and comprises an upper shell 11 and a lower shell 12, which are spliced to form a hollow bionic fish body, and a sealing structure 13 is arranged between the upper shell 11 and the lower shell 12. The magnetic driving device 2 is installed in the hollow bionic fish body 1, the magnetic driving device 2 is provided with a permanent magnet module 21, an electromagnetic module 22, a control module 23 and a swing module 24, the control module 23 receives external instructions to power the electromagnetic module 22, and controls the electromagnetic module 22 to periodically generate opposite direction magnetic field, and the magnetic force between the permanent magnet module 21 forms a torque to drive the swing module 24 to reciprocate, and the swing module 24 is connected with the fish tail 3. The fish tail 3 comprises a tail handle 31 and a tail fin 32, the tail handle 31 is curved at one end close to the bionic fish body 1, and the tail fin 32 is crescent-shaped.

[0022] It should be noted that the curved structure of the tail handle 31 close to one end of the bionic fish body 1 can ensure that there is no interference between the tail handle 31 and the bionic fish body 1 when the swing module 24 swings to the maximum swing amplitude, so that the swing angle is prevented from being changed due to the contact between the bionic fish body 1 and the tail handle 31.

[0023] Please refer to Figure 4 In the embodiment, further description, the sealing structure 13 comprises: an annular sealing groove 131, a waterproof rubber strip 132, a fastening unit 133, the annular sealing groove 131 is arranged at the connecting position of the upper shell 11 and the lower shell 12, the waterproof rubber strip 132 is installed in the annular sealing groove 131 and is compressed by the upper shell 11 and the lower shell 12, and the fastening unit 133 is used for connecting and fixing the upper shell 11 and the lower shell 12.

[0024] Specifically, the fastening unit 133 can be bolt fastening, bolt holes are arranged at the edges of the upper shell 11 and the lower shell 12, and the upper shell and the lower shell are fastened by assembling bolts; the fastening unit 133 can also be lock fastening, a lock body is arranged at the edge of the upper shell 11, a lock groove is arranged at the edge of the lower shell 12, the lock body and the lock groove are engaged, and fastening is performed; the fastening unit 133 can also glue the upper shell and the lower shell.

[0025] Please refer to Figure 1 In order to make the movement of the bionic robotic fish more stable, the chest fin 14, the belly fin 15 and the back fin 16 are arranged outside the bionic fish body 1 in the embodiment, the chest fin 14, the belly fin 15 and the back fin 16 are arranged in a cross rudder mode, the length of the belly fin 15 is consistent with that of the back fin 16, such symmetrical arrangement can simplify the mechanical structure, and can provide natural fluid damping when the bionic robotic fish is static or moves in a straight line, reduce the influence of external disturbance on the balance of the fish body, and enhance the stability.

[0026] In the embodiment, the cross-sectional length of the bionic fish body 1 is greater than the cross-sectional length of the fish tail 3, the length of the fish tail 3 is 1 / 2-1 / 3 of the total length of the bionic robotic fish, the design concept refers to the swimming posture of the carangidae, and the spiral motion of the fish body, i.e., the left-right swing, can be effectively inhibited, so that the spiral motion of the fish body has a negligible influence on the forward movement of the bionic fish.

[0027] Please refer to Figures 5-6 In the embodiment, the magnetic driving device 2 is provided with a split shell 25, the split shell 25 is provided with a groove 251 at the split position, the split shell 25 is provided with a rotating disc 26 at the central axis, the permanent magnet module 21 is a four-segment fan-shaped magnet, the four-segment fan-shaped magnet is installed on the rotating disc 26 in a counterclockwise direction according to the SN-NS or NS-SN magnetic pole sequence, the rotating disc 26 is provided with a rotating shaft 261 at the central axis, the rotating shaft 261 is installed at the top and the bottom of the split shell 25, respectively, the split shell 25 is provided with a fixed hole 252 and a wire hole 253 at intervals of 90° around the inner wall, the electromagnetic module 22 is composed of a stator core 221 and a coil 222 wound on the stator core 221, the stator core 221 is provided with a spline 223 at the bottom, the spline 223 is fixed on the fixed hole 252, the coil 222 is connected to the control module 23 after being led out of the split shell 25 through the wire hole 253, and the electromagnetic module 22 and the permanent magnet module 21 are located at the same horizontal height.

[0028] It should be noted that the electromagnetic module 22 and the permanent magnet module 21 are located at the same horizontal height, which can avoid the useless vertical component force of the magnetic force of the electromagnetic module 22 and the permanent magnet module 21, and considering that the rotating shaft 261 of the rotating disc 26 needs to bear the axial load during operation and also bears the radial load generated by gravity, a thrust aligning roller bearing is assembled at both ends of the rotating disc 26, and the bearing outer ring is assembled on the split shell 25.

[0029] In some embodiments, the material of the stator core 221 of the electromagnetic module 22 is a silicon steel sheet, which contains a small amount of silicon, can reduce the magnetic field loss, and has a high cost performance, the coil 222 is made of copper material, the fan-shaped magnet material of the permanent magnet module 21 is selected as Rb-Fe-B N35, compared with the traditional materials such as ferrite and alnico, the magnetic flux is larger, the volume is smaller, the weight is lighter, and it can remain normal within the range of 0° and 80°, can adapt to the maximum working temperature, and the cost is lower than that of other rare earth magnets.

[0030] Please refer to Figures 4-5In the embodiment, the swing module 24 is hinged at the edge of the rotating disc 25, the swing module 24 is a swing rod, one end of the swing rod is hinged at the edge of the rotating disc 25 through a stepped pin 241, the swing rod passes through a groove 251 of the shell 25 of the magnetic driving device 2, a notch 242 is arranged at the middle of the swing rod, the notch 242 is matched and installed with the limiting column 17 of the bionic fish body 1, the limiting column 17 limits the limit position of the swing of the two ends of the swing rod, and the center position of the fan-shaped magnet and the central axis of the corresponding electromagnetic module 22 always keep a certain angle when the rotating disc 26 is driven to rotate by the magnetic force.

[0031] It should be noted that the notch 242 of the swing rod is assembled with the limiting column 17, when the rotating disc 26 rotates, the hinged end of the swing rod swings synchronously, the notch 242 and the limiting column 17 act as a lever fulcrum, so that the other end of the swing rod swings reversely, at the same time, the notch 242 can avoid the rotating disc 26 from being stuck by the forward and backward movement of the swing rod when it rotates; in addition, the notch 242 is arranged at the middle of the swing rod, which is considered that if the position of the notch 242 is close to the rotating disc 26, according to the lever balance condition, the force arm of the resistance in the water of the fish tail will be much larger than the force arm of the magnetic driving device, which will increase the demand for driving force, thereby improving the complexity of the overall design and increasing the cost to some extent, and if the position is too far back, the swing angle of the fish tail 3 will be limited, and the insufficient swing angle will cause the component force of the driving force generated by the magnetic driving device 2 in the forward direction to weaken, which cannot effectively overcome the resistance encountered by the bionic fish when it moves forward in the water, thereby affecting the forward speed, and even possibly resulting in the failure to achieve the expected moving effect, therefore, the design of the notch 242 at the middle of the swing rod is the best choice after considering various factors; the length of the notch 242 is designed considering that when the swing rod swings to the maximum amplitude, there is a certain angle between the center position of the fan-shaped magnet and the central axis of the corresponding electromagnetic module 22, so that when the current direction of the electromagnetic module 22 is changed, the forces on the left and right sides of the fan-shaped magnet are unbalanced, and the swing rod can swing back and forth.

[0032] The tail handle 31 and the tail fin 32 are provided with through holes 33 in the middle, the swing rod passes through the through holes 33 to connect and fix the tail handle 31 and the tail fin 32 after passing out of the bionic fish body 1, and the swing rod has elasticity.

[0033] Please refer to Figures 7-8 The embodiment also provides a bionic robotic fish propulsion method based on magnetic force driving, which comprises the following steps: S1, the control module 23 receives external instructions, initializes the magnetic driving device 2, resets the swing rod, and makes the swing rod and the main shaft of the bionic fish body 1 collinear; S2, propulsion execution, the control module 23 controls the electromagnetic module 22 to periodically generate magnetic fields in different directions, and the magnetic force between the electromagnetic module 22 and the permanent magnet module 21 forms a torque to drive the swing module 24 to swing back and forth; The S3 swing module 24 drives the tail handle 31 and the tail fin 32 to swing back and forth, and pushes the bionic fish body 1 to move forward.

[0034] In S1, when the swing rod is reset to be collinear with the main shaft of the bionic fish body, the swing module is set to swing right for the first time, the sector magnet at the hinge of the swing rod is the first sector magnet 211, the center line of the first sector magnet 211 is adjusted to keep a right deflection angle with the central axis of a certain electromagnetic module, which is the first electromagnetic module 22A, the other electromagnetic modules arranged counterclockwise are the second electromagnetic module 22B, the third electromagnetic module 22C and the fourth electromagnetic module 22D, and the corresponding sector magnets are the second sector magnet 212, the third sector magnet 213 and the fourth sector magnet 214.

[0035] In S2, if the S pole of the first sector magnet 211 is on the left and the N pole is on the right, the magnetic induction line direction outside the first sector magnet 211 is from N to S, the control module 23 controls the first electromagnetic module 22A to generate a magnetic field, the internal magnetic induction line of the stator core is from outside to inside, and the external magnetic induction line is from inside to outside, the control module 23 controls the second electromagnetic module 22B on the right side of the first sector magnet 211 to generate a magnetic field, the internal magnetic induction line of the stator core is from inside to outside, and the external magnetic induction line is from outside to inside, since the center line of the first sector magnet 211 keeps a right deflection angle with the central axis of the first electromagnetic module 22A, the magnetic induction line direction outside the first sector magnet 211 is opposite to the magnetic induction line direction of the first electromagnetic module 22A close to the first sector magnet 211, the first sector magnet 211 is pushed to rotate counterclockwise, and the second sector magnet 212 is pushed to rotate counterclockwise by the second electromagnetic module 22B in the same way, and the other two electromagnetic modules push the corresponding sector magnets, so that the rotating disc rotates counterclockwise, and the swing module 24 swings right; when the swing module 24 swings right to the limit position, the control module 23 changes the current direction of each electromagnetic module 22, so as to control the rotating disc 26 to rotate clockwise, the swing module 24 swings left, and the reciprocating swing is realized.

[0036] In the description of the present application, unless otherwise specified and limited, the terms "mounting", "connection" and "connection" should be understood in a broad sense, for example, it can be fixed connection, or indirect connection through an intermediate medium, or internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] In the description of the present application, the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0038] The terms "first", "second", "third" (if any) in the description, claims, and drawings of the present application are used to distinguish similar objects, and do not necessarily have to be used to describe a particular order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the described embodiments of the application can be implemented in an order other than those illustrated or described herein.

[0039] In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or maintenance tool including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or maintenance tools.

[0040] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should be regarded as the protection scope of the present application, and these will not affect the effect and practicality of the implementation of the present application.

Claims

1. A biomimetic robotic fish based on magnetic force drive, characterized in that: include, Bionic fish body (1), magnetic drive device (2), fish tail (3); The bionic fish body (1) has an elliptical cross section perpendicular to the main axis of the body and a spindle shape with an approximate parabola in the longitudinal section. The bionic fish body includes an upper shell (11) and a lower shell (12). The upper shell (11) and the lower shell (12) are spliced ​​together to form a hollow bionic fish body. A sealing structure (13) is provided between the upper and lower shells. The magnetic drive device (2) is installed inside the hollow bionic fish body (1). The magnetic drive device (2) is equipped with a permanent magnet module (21), an electromagnetic module (22), a control module (23) and a swing module (24). The control module (23) receives external instructions to power the electromagnetic module (22) and controls the electromagnetic module (22) to periodically generate a magnetic field in the opposite direction. The magnetic force between the electromagnetic module (21) and the permanent magnet module (21) forms a torque, which drives the swing module (24) to swing back and forth. The swing module (24) is connected to the fish tail (3). The fish tail (3) includes a caudal peduncle (31) and a caudal fin (32). The caudal peduncle (31) has a curved structure near the end of the biomimetic fish body (1), and the caudal fin (32) is crescent-shaped.

2. The biomimetic robotic fish based on magnetic drive according to claim 1, characterized in that: The magnetic drive device (2) is provided with a shell (25) that can be split vertically. The shell (25) has a groove (251) at the split point. A rotating disk (26) is provided at the central axis inside the shell (25). The permanent magnet module (21) is a four-segment sector magnet. The four sector magnets are installed counterclockwise on the rotating disk (26) in the order of SN-NS or NS-SN magnetic poles. A rotating shaft (261) is provided at the central axis of the rotating disk (26). The two ends of the rotating shaft (261) are respectively installed at the top and bottom of the shell (25). The four segments of permanent magnet module (21) are four-segment sector magnets. The electromagnetic module (22) is provided with a fixing hole (252) and a wire passage hole (253) at 90° intervals. The electromagnetic module (22) consists of a stator core (221) and a coil (222) wound on the stator core (221). A spline (223) is installed at the bottom of the stator core (221). The spline (223) is fixed on the fixing hole (252). The two ends of the coil (222) are led out of the housing (25) through the wire passage hole (253) and connected to the control module (23). The electromagnetic module (22) and the permanent magnet module (21) are located at the same horizontal height.

3. The biomimetic robotic fish based on magnetic drive according to claim 2, characterized in that: The rotating disk (25) is hinged to the edge of the swing module (24), the swing module (24) is a swing rod, one end of the swing rod is hinged to the edge of the rotating disk (25) by a stepped pin (241), the swing rod passes through the groove (251) of the housing (25) of the magnetic drive device (2), the swing rod is provided with a slot (242) in the middle, the bionic fish body (1) is provided with a limiting post (17), the slot (242) and the limiting post (17) are installed together to limit the extreme position of the swing rod at both ends, and when the rotating disk (26) is driven to rotate by magnetic force, the center position of the fan magnet and the central axis of the corresponding electromagnetic module (22) always maintain a certain angle.

4. The biomimetic robotic fish based on magnetic drive according to claim 3, characterized in that: After the swing rod passes through the bionic fish body (1), it is fixed to the fish tail (3). The tail (3) has a through hole (33) in the middle of the caudal peduncle (31) and the caudal fin (32). The swing rod is fixed by connecting the caudal peduncle (31) and the caudal fin (32) through the through hole (33). The swing rod is elastic.

5. The biomimetic robotic fish based on magnetic drive according to claim 1, characterized in that: The sealing structure (13) includes: an annular sealing groove (131), a waterproof strip (132), and a fastening unit (133). The annular sealing groove (131) is located at the connection between the upper housing (11) and the lower housing (12). The waterproof strip (132) is installed in the annular sealing groove (131) and is pressed by the upper housing (11) and the lower housing (12). The fastening unit (133) is used to connect and fix the upper housing (11) and the lower housing (12).

6. The biomimetic robotic fish based on magnetic drive according to any one of claims 1-5, characterized in that: The biomimetic fish body (1) is provided with pectoral fins (14), pelvic fins (15) and dorsal fins (16) on the outside. The pectoral fins (14), pelvic fins (15) and dorsal fins (16) are arranged in a cross-shaped manner. The pelvic fins (15) and dorsal fins (16) are the same length.

7. The biomimetic robotic fish based on magnetic drive according to any one of claims 1-5, characterized in that: The cross-sectional extension of the bionic fish body (1) is greater than that of the cross-sectional extension of the fish tail (3), and the length of the fish tail (3) is 1 / 2 to 1 / 3 of the total length of the bionic robotic fish.

8. A method for propulsion of a biomimetic robotic fish based on magnetic force, characterized in that, include: The S1 control module receives external commands, initializes the magnetic drive device, and resets the swing arm to be collinear with the main axis of the bionic fish body. S2 propulsion execution: the control module controls the electromagnetic module to periodically generate magnetic fields in different directions, which form torque with the magnetic force between the electromagnetic module and the permanent magnet module, driving the swing module to swing back and forth. The S3 oscillation module drives the caudal peduncle and caudal fin to oscillate back and forth, propelling the bionic fish body forward.

9. The biomimetic robotic fish propulsion method based on magnetic drive according to claim 8, characterized in that: In S1, when the swing rod is reset and collinear with the main axis of the bionic fish body, the initial swing of the swing module is set to swing to the right. The sector magnet at the hinge of the swing rod is the first sector magnet. The position of the center line of the first sector magnet is adjusted to maintain a rightward deflection angle with the central axis of a certain electromagnetic module. This electromagnetic module is the first electromagnetic module. The other electromagnetic modules arranged counterclockwise are the second electromagnetic module, the third electromagnetic module, and the fourth electromagnetic module, and the corresponding sector magnets are the second sector magnet, the third sector magnet, and the fourth sector magnet, respectively.

10. The biomimetic robotic fish propulsion method based on magnetic drive according to claim 9, characterized in that: In S2, if the S pole of the first sector magnet is on the left and the N pole is on the right, then the direction of the magnetic field lines outside the first sector magnet is from N to S. The control module controls the first electromagnetic module to generate a magnetic field, with the magnetic field lines inside its stator core running from the outside to the inside and the magnetic field lines outside running from the inside to the outside. The control module controls the second electromagnetic module to the right of the first sector magnet to generate a magnetic field, with the magnetic field lines inside its stator core running from the inside to the outside and the magnetic field lines outside running from the outside to the inside. Because the center line of the first sector magnet and the central axis of the first electromagnetic module maintain a rightward deflection angle, the direction of the magnetic field lines outside the first sector magnet is perpendicular to that of the first electromagnetic module. The magnetic field lines of the block near the first sector magnet are in opposite directions, causing the first sector magnet to rotate counterclockwise. Similarly, the center line of the second sector magnet and the central axis of the second electromagnetic module maintain a rightward deflection angle, causing the second electromagnetic module to rotate the second sector magnet counterclockwise. Similarly, the other two electromagnetic modules drive their corresponding sector magnets, thereby causing the rotating disk to rotate counterclockwise and the oscillating module to oscillate to the right. When the oscillating module oscillates to its right limit, the control module changes the current direction of each electromagnetic module, thereby controlling the rotating disk to rotate clockwise and the oscillating module to oscillate to the left, achieving reciprocating oscillation.

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