Buoyancy-adjustable amphibious bionic manta ray robot based on piezoelectric driving

Abstract

The invention discloses a buoyancy-adjustable amphibious bionic manta ray robot based on piezoelectric driving, and belongs to the technical field of underwater robots, the amphibious bionic manta ray robot comprises a shell, the shell comprises a manta ray-shaped shell and a belly armor, and piezoelectric bimorph fixing plate mounting holes are symmetrically formed in the two side faces of the belly armor; the piezoelectric bimorph fixing plate mounting hole is connected with a driving assembly through a bolt, a base mounting groove is formed in the belly armor, a power assembly is mounted in the base mounting groove, and the power assembly is connected with an adjusting assembly. According to the buoyancy-adjustable amphibious bionic manta ray robot based on piezoelectric driving, excitation signals with different phase differences are applied to the adjacent piezoelectric bimorphs, so that the piezoelectric bimorphs vibrate in sequence, and movement in water is achieved; the same excitation signals are applied to the piezoelectric bimorph, so that the piezoelectric bimorph vibrates in a reciprocating mode, land movement is achieved, the structure is simple, the driving efficiency is high, underwater efficient propelling is achieved, land movement is considered, and the robot has the buoyancy adjusting function and can achieve rapid rising and floating and precise hovering.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater robots, and more particularly to an amphibious biomimetic manta ray robot with adjustable buoyancy based on piezoelectric drive. Background Art

[0002] In recent years, biomimetic underwater robots have become a research hotspot in fields such as ocean exploration, ecological monitoring, and military reconnaissance due to their characteristics of high-efficiency propulsion, flexibility, and strong environmental adaptability. Among them, biomimetic robots that imitate the biological form and movement mechanism of manta rays have attracted much attention. These robots generate wave-like motions (fluctuations or swings) through flexible pectoral fins to drive their own movement, with the advantages of low disturbance and high propulsion efficiency. Moreover, the flexible pectoral fins can adapt to complex water currents and maintain a stable trajectory in wave areas or ocean currents, making them suitable for operating in complex underwater environments. However, most existing biomimetic manta ray robots use crank-rocker mechanisms or servo motors to drive the movement of flexible pectoral fins. The mechanical transmission system is complex and the energy loss is significant. It is difficult to balance high-efficiency underwater propulsion and on-land movement capabilities, and lacks adaptability to the water-land transition environment. At the same time, due to their complex drive mechanisms, existing biomimetic manta ray robots are difficult to integrate a buoyancy adjustment system, unable to achieve rapid diving and floating or hovering, which limits the operation ability of the robots in dynamic water currents or narrow spaces. Summary of the Invention

[0003] The purpose of the present invention is to provide an amphibious biomimetic manta ray robot with adjustable buoyancy based on piezoelectric drive. Multiple piezoelectric bimorphs are arranged according to a certain rule, and excitation signals with different phase differences are applied to adjacent piezoelectric bimorphs to make them vibrate in sequence to generate a traveling wave in a certain direction, driving the biomimetic manta ray robot to move in water. The same excitation signal is applied to multiple piezoelectric bimorphs to make them generate reciprocating vibrations, driving the biomimetic manta ray robot to move on land. The structure is simple and the drive efficiency is high. While achieving high-efficiency underwater propulsion, it can also balance good on-land movement capabilities. Moreover, the robot is equipped with a buoyancy adjustment component powered by a piezoelectric motor, which can achieve rapid ascent and precise hovering.

[0004] To achieve the above purpose, the present invention provides an amphibious biomimetic manta ray robot with adjustable buoyancy based on piezoelectric drive, including a housing. The housing includes a manta ray-shaped outer shell and a ventral carapace. Symmetrically arranged piezoelectric bimorph fixing plate mounting holes are provided on both sides of the ventral carapace. The piezoelectric bimorph fixing plate mounting holes are connected with a drive component through bolts. A base mounting groove is arranged inside the ventral carapace, and a power component is mounted in the base mounting groove. The power component is connected with an adjustment component.

[0005] Preferably, the manta ray-shaped outer shell is provided with a ventral carapace mounting groove, and the ventral carapace is bonded to the ventral carapace mounting groove with epoxy resin glue.

[0006] Preferably, the driving component includes a piezoelectric bimorph fixing plate, which is provided with a spring fixing lower groove, and the spring fixing lower groove cooperates with a spring fixing upper groove arranged on the plastron. A piezoelectric bimorph fixing groove is installed on the piezoelectric bimorph fixing plate, and the piezoelectric bimorph is bonded to a bimorph fixer, and the bimorph fixer is inserted into the piezoelectric bimorph fixing groove. The piezoelectric bimorph fixing grooves and the piezoelectric bimorphs are arranged in groups and the number is not less than one group. A wire hole is opened in the piezoelectric bimorph fixing groove, and a thin film is bonded to the piezoelectric bimorph.

[0007] Preferably, the power component includes a base arranged in the base installation groove. A pre-tightening spring mounting seat is arranged inside the base, and pre-tightening spring mounting holes are arranged around the pre-tightening spring mounting seat. A pre-tightening spring is arranged in the pre-tightening spring mounting hole, and a motor seat is installed at the top end of the pre-tightening spring. A compression spring post cooperating with the pre-tightening spring is arranged on the lower surface of the motor seat. A paired pre-tightening adjustment bolt and pre-tightening adjustment nut are arranged through the central positions of the base, the pre-tightening spring mounting seat and the motor seat; A motor installation groove is arranged at the top end of the motor seat, and a piezoelectric motor main body is installed in the motor installation groove. The piezoelectric motor main body is fixed by the cooperation of a pressing plate and the motor seat; Bearing seats are installed on both sides of the base, bearings are installed in the bearing seats, a turntable is installed in the bearings, and the output end of the turntable is connected to the adjusting component.

[0008] Preferably, piezoelectric ceramics are arranged below the middle beam, on the side of the front beam and on the side of the rear beam of the piezoelectric motor main body, and a driving foot cooperating with the turntable is arranged above the middle beam.

[0009] Preferably, the adjusting component includes a coupling, the output end of the coupling is connected to the input end of a reducer, the output end of the reducer is connected to the head end of a rotating shaft by a set screw, a rotating shaft nut installation groove is arranged at the tail end of the rotating shaft, a rotating shaft nut is installed in the rotating shaft nut installation groove, a rotating shaft bolt is installed in the rotating shaft nut, the tail end of the rotating shaft bolt is fixedly connected to the lower section of a connecting plate, the upper section of the connecting plate is fixedly connected to the tail end of a piston rod, and the head end of the piston rod is fixedly connected to a piston. The piston is located inside a syringe, and the syringe is fixed to an intermediate partition by bolts.

[0010] Preferably, the coupling, the reducer, the rotating shaft and the rotating shaft bolt are located below the intermediate partition, the piston rod, the piston and the syringe are located above the intermediate partition, and a reducer upper fixing plate for fixing the reducer and a rotating shaft upper fixing plate for fixing the rotating shaft are arranged below the intermediate partition; The reducer upper fixing plate and the rotating shaft upper fixing plate cooperate with a reducer lower fixing plate and a rotating shaft lower fixing plate arranged on the plastron.

[0011] Therefore, the present invention adopts the above-mentioned amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive, and has the following beneficial effects: 1) The positions such as the wire welding place of the piezoelectric bimorph, the ventral carapace mounting groove, and the piezoelectric ceramics can be directly used underwater after applying epoxy resin glue, without the need for additional sealing devices, reducing the risk of the whole machine failure caused by seal failure, and having high reliability.

[0012] 2) The piezoelectric motor can achieve displacement control with nanometer-level or even higher precision, and can adjust the buoyancy in real time and accurately; at the same time, the high response speed of the piezoelectric motor can match the instantaneous change of water pressure, greatly improving the environmental adaptability of the bionic manta ray robot.

[0013] 3) By adjusting the driving force difference between the fins on both sides of the bionic manta ray robot, the robot can flexibly complete forward movement, turning and rotation; by applying appropriate excitation signals to the piezoelectric motor, the robot can achieve ascending, descending and hovering, with high flexibility, mobility and controllability.

[0014] 4) The piezoelectric bimorph is both a driver and an actuator at the same time, without a traditional system, eliminating the risk of the whole machine failure caused by transmission system failures while improving the driving efficiency.

[0015] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0016] Figure 1 is the external structure diagram of an embodiment of the amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive of the present invention; Figure 2 is the schematic diagram of the housing of an embodiment of the amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive of the present invention; Figure 3 is the ventral carapace structure diagram of an embodiment of the amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive of the present invention; Figure 4 is the drive component structure diagram of an embodiment of the amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive of the present invention; Figure 5 is the piezoelectric bimorph fixing plate structure diagram of an embodiment of the amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive of the present invention; Figure 6 is the exploded view of the power component of an embodiment of the amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive of the present invention; Figure 7It is the structural diagram of the base of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 8 It is the structural diagram of the pre-tightening spring mounting seat of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 9 It is the structural diagram of the motor seat of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 10 It is the structural diagram of the piezoelectric motor of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 11 It is the structural diagram of the bearing seat of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 12 It is the structural diagram of the adjustment component of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 13 It is the structural diagram of the middle partition of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 14 It is the cross-sectional view of the rotating shaft of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 15 It is the structural diagram of the pressing plate of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 16 It is the structural diagram of the connecting plate of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 17 It is the schematic diagram of the syringe of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 18 It is the underwater movement diagram of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 19 It is the on-land movement diagram of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention; Figure 20 It is the buoyancy adjustment diagram of an embodiment of a piezoelectric-driven adjustable buoyancy amphibious bionic manta ray robot of the present invention.

[0017] Reference numerals 1. Manta ray-shaped housing; 2. Abdominal armor; 3. Abdominal armor mounting groove; 4. Piezoelectric bimorph fixing plate mounting hole; 5. Lower fixing plate of the rotating shaft; 6. Lower fixing plate of the reducer; 7. Base mounting groove; 8. Upper spring fixing groove; 9. Piezoelectric bimorph fixing plate; 10. Bimorph fixator; 11. Piezoelectric bimorph; 12. Film; 13. Fixing plate spring; 14. Nut; 15. Bolt; 16. Piezoelectric bimorph fixing groove; 17. Wire hole; 18. Mounting hole; 19. Lower spring fixing groove; 20. Base; 21. Pre-tightening spring mounting seat; 22. Pre-tightening spring; 23. Motor seat; 24. Bearing seat; 25. Piezoelectric ceramic; 26. Piezoelectric motor main body; 27. Pressure plate; 28. Turntable; 29. Bearing; 30. Pre-tightening adjustment nut; 31. Pre-tightening adjustment bolt; 32. Wire hole II; 33. Nut mounting groove; 34. Pre-tightening spring mounting seat mounting groove; 35. Pre-tightening adjustment bolt mounting hole; 36. Pre-tightening spring mounting hole; 37. Pre-tightening adjustment bolt mounting hole II; 38. Motor mounting groove; 39. Pre-tightening adjustment nut mounting hole; 40. Compression spring column; 41. Intermediate beam; 42. Driving foot; 43. Rear beam; 44. Front beam; 45. Bolt mounting hole; 46. Bearing mounting hole; 47. Coupling; 48. Reducer; 49. Set screw; 50. Rotating shaft; 51. Rotating shaft nut; 52. Rotating shaft bolt; 53. Connecting plate; 54. Piston rod; 55. Piston; 56. Syringe; 57. Intermediate partition; 58. Upper fixing plate of the reducer; 59. Upper fixing plate of the rotating shaft; 60. Set screw mounting hole; 61. Rotating shaft nut mounting groove; 62. Rotating shaft bolt fixing hole; 63. Piston rod fixing hole. Detailed implementation manners

[0018] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Unless otherwise defined, the technical terms or scientific terms used in the present invention should have the ordinary meanings understood by those of ordinary skill in the field to which the present invention belongs. The "first", "second" and similar terms used in the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "comprising" or "including" mean that the elements or objects appearing before this term cover the elements or objects listed after this term and their equivalents, without excluding other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left", "right" are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0020] Embodiment 1 The present invention provides an amphibious biomimetic manta ray robot with adjustable buoyancy based on piezoelectric drive, and its external structure is as shown in Figure 1 shown, including a housing, the housing is as shown in Figure 2 shown, including a manta ray-shaped outer shell 1 and a ventral carapace 2. The manta ray-shaped outer shell 1 is provided with a ventral carapace mounting groove 3, and the ventral carapace 2 is bonded to the ventral carapace mounting groove 3 by epoxy resin glue. The structure of the ventral carapace 2 is as shown in Figure 3 shown.

[0021] On both sides of the ventral carapace 2, piezoelectric bimorph fixing plate mounting holes 4 are symmetrically arranged, and a drive assembly is connected to the piezoelectric bimorph fixing plate mounting holes 4 by bolts. The drive assembly is as shown in Figure 4 shown, including a piezoelectric bimorph fixing plate 9. The piezoelectric bimorph fixing plate 9 is as shown in Figure 5 shown. Its mounting hole 18 is coaxially matched with the piezoelectric bimorph fixing plate mounting hole 4 and is connected by a nut 14 and a bolt 15. The bolt 15 has a clearance fit with both the mounting hole 18 and the piezoelectric bimorph fixing plate mounting hole 4, and the piezoelectric bimorph fixing plate 9 can rotate around the axis of the piezoelectric bimorph fixing plate mounting hole 4.

[0022] A piezoelectric bimorph fixing groove 16 is installed on the piezoelectric bimorph fixing plate 9. The installation angles of the piezoelectric bimorph fixing grooves 16 can be independently and flexibly adjusted according to the device debugging situation. By adjusting the installation angles of the piezoelectric bimorph fixing grooves 16, the installation angles of the piezoelectric bimorphs 11 are further adjusted. The piezoelectric bimorphs 11 are bonded to the bimorph holders 10 by epoxy resin glue, and the bimorph holders 10 are inserted into the piezoelectric bimorph fixing grooves 16. There is an interference fit between the bimorph holders 10 and the piezoelectric bimorph fixing grooves 16. The piezoelectric bimorph fixing grooves 16 and the piezoelectric bimorphs 11 are set in groups and the number is not less than one group. The piezoelectric bimorph fixing grooves 16 are provided with wire holes 17, and the wire holes 17 are used to lead out the wires of the piezoelectric bimorphs 11. The piezoelectric bimorphs 11 are bonded with films 12.

[0023] The piezoelectric bimorph fixing plate 9 is provided with a spring fixing lower groove 19, and the spring fixing lower groove 19 cooperates with the spring fixing upper groove 8 provided on the ventral carapace 2. One end of the fixing plate spring 13 is bonded to the spring fixing upper groove 8 by epoxy resin glue, and the other end is bonded to the spring fixing lower groove 19 by epoxy resin glue. Under the action of the fixing plate spring 13, when the device moves on land, it can ensure that the end of the piezoelectric bimorph 11 always remains in contact with the ground.

[0024] Inside the ventral carapace 2, a base mounting groove 7 is provided, and a power assembly is installed in the base mounting groove 7. The explosion diagram of the power assembly is as shown in Figure 6 shown, and the power assembly includes a base 20 arranged in the base mounting groove 7. The base 20 is as shown in Figure 7As shown, a pre-tightening spring mounting seat installation groove 34 is provided inside the base 20. A pre-tightening spring mounting seat 21 is bonded inside the pre-tightening spring mounting seat installation groove 34. The pre-tightening spring mounting seat 21 is as Figure 8 shown. Pre-tightening spring mounting holes 36 are provided around the pre-tightening spring mounting seat 21. A pre-tightening spring 22 is provided inside the pre-tightening spring mounting holes 36. The top end of the pre-tightening spring 22 is provided with a motor seat 23. The motor seat 23 is as Figure 9 shown. A spring pressing column 40 that cooperates with the pre-tightening spring 22 is provided on the lower surface of the motor seat 23.

[0025] A pre-tightening adjustment bolt installation hole 35 is provided at the center of the base 20. A pre-tightening adjustment bolt installation hole II 37 is provided at the center of the pre-tightening spring mounting seat 21. A pre-tightening adjustment nut installation hole 39 is provided at the center of the motor seat 23. A paired pre-tightening adjustment bolt 31 and pre-tightening adjustment nut 30 are provided through the central positions of the base 20, the pre-tightening spring mounting seat 21, and the motor seat 23; the pre-tightening adjustment nut 30 is fixedly installed in the pre-tightening adjustment nut installation hole 39, and the pre-tightening adjustment bolt 31 passes through the pre-tightening adjustment bolt installation hole 35 and the pre-tightening adjustment bolt installation hole II 37 to cooperate with the pre-tightening adjustment nut 30. Rotating the pre-tightening adjustment bolt 31 makes the motor seat 23 move along the axis of the pre-tightening adjustment bolt 31, thereby adjusting the pre-tightening force.

[0026] A motor installation groove 38 is provided at the top end of the motor seat 23. A piezoelectric motor main body 26 is installed inside the motor installation groove 38. The piezoelectric motor main body 26 is fixed through the cooperation of the bolt holes of a pressing plate 41 ( Figure 15 ) and the nut installation groove 33 provided on the motor seat 23. Bearing seats 24 are installed on both sides of the base 20. The bearing seats 24 are as Figure 11 shown and are fixed through bolt installation holes 45 and the nut installation groove 33 provided on the base 20. A bearing installation hole 46 is machined on the bearing seat 24. A bearing 29 is installed inside the bearing installation hole 46. A turntable 28 is installed inside the bearing 29. The output end of the turntable 28 is connected with an adjustment assembly.

[0027] The piezoelectric motor is as Figure 10 shown. Piezoelectric ceramics 25 are provided below the middle beam 41, on the side surfaces of the front beam 44, and on the side surfaces of the rear beam 43 of the piezoelectric motor main body 26. In this embodiment, the piezoelectric ceramics 25 are bonded to each beam through epoxy resin glue. A driving foot 42 that cooperates with the turntable 28 is provided above the middle beam 41.

[0028] The adjustment assembly is as Figure 12 shown and includes a coupling 47. The output end of the coupling 47 is connected with the input end of a speed reducer 48. The output end of the speed reducer 48 is connected with the head end of a rotating shaft 50 through a set screw 49. The rotating shaft 50 and the output end of the speed reducer 48 rotate together. The cross-sectional view of the rotating shaft 50 is as Figure 14As shown, a rotating shaft nut installation groove 61 is provided at its end. A rotating shaft nut 51 is installed in the rotating shaft nut installation groove 61, and a rotating shaft bolt 52 is installed in the rotating shaft nut 51. The rotating shaft nut 51 and the rotating shaft bolt 52 cooperate to form a screw pair. The end of the rotating shaft bolt 52 is fixedly connected in a rotating shaft bolt fixing hole 62 at the lower section of a connecting plate 53. The piston rod fixing hole 63 at the upper section of the connecting plate 53 is fixedly connected to the end of a piston rod 54. The connecting plate 53 is as Figure 16 shown. The head end of the piston rod 54 is fixedly connected to a piston 55, and the piston 55 is located inside a syringe barrel 56. The syringe barrel 56 is as Figure 17 shown and is fixed to an intermediate partition 57 by bolts. The connecting plate 53 restricts the rotation of the rotating shaft bolt 52. Therefore, the rotation of the rotating shaft 50 is converted into the linear movement of the rotating shaft bolt 52. Since the connecting plate 53 connects the rotating shaft bolt 52 and the piston rod 54 into one body, the piston rod 54 will also perform linear motion, and the motion direction is the same as that of the rotating shaft bolt 52.

[0029] The intermediate partition 57 is as Figure 13 shown. A coupling 47, a speed reducer 48, a rotating shaft 50 and a rotating shaft bolt 52 are located below the intermediate partition 57, and a piston rod 54, a piston 55 and a syringe barrel 56 are located above the intermediate partition 57. A speed reducer upper fixing plate 58 for fixing the speed reducer 48 and a rotating shaft upper fixing plate 59 for fixing the rotating shaft 50 are provided below the intermediate partition 57; the speed reducer upper fixing plate 58 and the rotating shaft upper fixing plate 59 cooperate with a speed reducer lower fixing plate 6 and a rotating shaft lower fixing plate 5 provided on the plastron 2.

[0030] In this device, the number and size of the piezoelectric bimorphs 11 can be determined according to the actual situation. The excitation signal applied to the piezoelectric bimorphs 11 can be any waveform, but it is necessary to ensure that the phase difference between any two adjacent piezoelectric bimorphs 11 is 90°. The lengths of the syringe barrel 56 and the rotating shaft bolt 52 can be determined according to the required buoyancy adjustment range, and the reduction ratio of the speed reducer 48 can be determined according to the required buoyancy adjustment accuracy.

[0031] Combined with Figures 1 - 5 and Figure 18 , the movement mode and principle of this device when moving in water are as follows: An excitation signal with a phase of x is applied to the piezoelectric bimorph 11 at the frontmost of both wings, an excitation signal with a phase of x + 90° is applied to the adjacent piezoelectric bimorph 11 at the rear, and the phase of the excitation signals of the subsequent piezoelectric bimorphs 11 increases by 90° in turn. The frequencies of all excitation signals are the same. When excitation signals with the same voltage are applied to the piezoelectric bimorphs 11 on the left wing and the piezoelectric bimorphs 11 on the right wing, the piezoelectric bimorphs 11 vibrate successively from front to back, and through the film 12 along Figure 18A traveling wave is generated in the direction shown, and the traveling wave motion of the thin film 12 causes a pressure difference in the surrounding fluid. When the thin film fluctuates upward, it pushes the fluid backward, and when it fluctuates downward, it utilizes the fluid flow to form an additional thrust to push the device forward. Since the voltages applied to the two piezoelectric bimorphs 11 of the two wings are the same, the additional thrusts formed by the two wings, i.e., the driving force of the left wing and the driving force of the right wing, are equal. Under the action of these two forces, the device moves forward. When the voltage of the excitation signal applied to the left piezoelectric bimorph 11 is greater than that of the right wing, the driving force of the left wing is greater than that of the right wing. Under the action of these two forces, the device realizes a right-turning motion. Similarly, when the voltage of the excitation signal applied to the right piezoelectric bimorph 11 is greater than that of the left wing, the device realizes a left-turning motion. When only the excitation signal is applied to the left piezoelectric bimorph 11, the device rotates clockwise. Similarly, when only the excitation signal is applied to the right piezoelectric bimorph 11, the device rotates counterclockwise.

[0032] Combined with Figures 1 - 5 、 Figure 19 , the movement mode and principle of the device during land movement are as follows: In the initial state, under the action of the spring 13, the end of the piezoelectric bimorph 11 is in contact with the ground. When the same excitation signal is applied to the piezoelectric bimorph 11, the piezoelectric bimorph 11 will generate reciprocating vibrations. When the piezoelectric bimorph 11 vibrates downward, it will generate a force on the ground, and the reaction force of the ground on the device is the driving force. Under the action of the horizontal component of the driving force, the device moves forward. When the voltage of the excitation signal applied to the left piezoelectric bimorph 11 is greater than that of the right wing, the driving force of the left wing is greater than that of the right wing. Under the action of these two forces, the device realizes a right-turning motion. Similarly, when the voltage of the excitation signal applied to the right piezoelectric bimorph 11 is greater than that of the left wing, the device realizes a left-turning motion. When only the excitation signal is applied to the left piezoelectric bimorph 11, the device will realize a clockwise rotation motion. Similarly, when only the excitation signal is applied to the right piezoelectric bimorph 11, the device will realize a counterclockwise rotation motion.

[0033] Combined with Figures 6 - 18 、 Figure 20 , the buoyancy adjustment method and principle of the device are as follows: An excitation signal is applied to the piezoelectric motor, which drives the turntable 28 to rotate in the positive direction. The turntable 28 transmits the rotation to the speed reducer 48 through the coupling 47. The speed reducer 48 drives the rotating shaft 50 to rotate. Since the rotating shaft nut 51 is installed on the rotating shaft 50 and forms a screw pair with the rotating shaft bolt 52, the rotation of the rotating shaft 50 is converted into the linear movement of the rotating shaft bolt 52 in the positive direction. Since the connecting plate 53 fixes the rotating shaft bolt 52 and the piston rod 54 respectively, the piston rod 54 and the piston 55 will also perform linear motion in the positive direction. The linear motion of the piston rod 54 and the piston 55 in the positive direction increases the overall volume of the device and the buoyancy. When the piezoelectric motor drives the turntable 28 to rotate in the direction opposite to the positive direction, the buoyancy decreases. The buoyancy is adjusted to be equal to the self-weight of the device to achieve hovering. When the buoyancy is greater than the gravity, the device moves upward. When the buoyancy is less than the gravity, the device moves downward.

[0034] Therefore, the present invention adopts the above-mentioned amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive, arranges multiple piezoelectric bimorphs according to a certain rule and applies excitation signals with different phase differences to adjacent piezoelectric bimorphs to make them vibrate in sequence to generate a traveling wave in a certain direction, driving the bionic manta ray robot to move in water; applying the same excitation signal to multiple piezoelectric bimorphs to make them generate reciprocating vibration, driving the bionic manta ray robot to move on land; with simple structure and high driving efficiency, it can achieve efficient underwater propulsion while taking into account good land movement ability. Moreover, the robot is equipped with a buoyancy adjustment component powered by a piezoelectric motor, which can achieve rapid lifting and precise hovering.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive, characterized in that: It includes a housing, and the housing includes a manta ray-shaped outer shell and a ventral carapace. Symmetrically arranged piezoelectric bimorph fixing plate mounting holes are provided on both sides of the ventral carapace. The piezoelectric bimorph fixing plate mounting holes are connected to a driving assembly by bolts. A base mounting groove is provided inside the ventral carapace, and a power assembly is mounted in the base mounting groove. The power assembly is connected to an adjusting assembly.

2. The amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive according to claim 1, characterized in that: The manta ray-shaped outer shell is provided with a ventral carapace mounting groove, and the ventral carapace is bonded to the ventral carapace mounting groove by epoxy resin glue.

3. The amphibious biomimetic manta ray robot with adjustable buoyancy based on piezoelectric drive according to claim 1, wherein: The driving assembly includes a piezoelectric bimorph fixing plate. The piezoelectric bimorph fixing plate is provided with a spring fixing lower groove, and the spring fixing lower groove cooperates with a spring fixing upper groove provided on the ventral carapace. A piezoelectric bimorph fixing groove is mounted on the piezoelectric bimorph fixing plate, and the piezoelectric bimorph is bonded to a bimorph holder. The bimorph holder is inserted into the piezoelectric bimorph fixing groove. The piezoelectric bimorph fixing grooves and the piezoelectric bimorphs are arranged in groups and the number is not less than one group. A wire hole is opened in the piezoelectric bimorph fixing groove, and a thin film is bonded to the piezoelectric bimorph.

4. An amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive according to claim 1, characterized in that: The power assembly includes a base arranged in the base mounting groove. A pre-tightening spring mounting seat is arranged inside the base. Pre-tightening spring mounting holes are provided around the pre-tightening spring mounting seat. A pre-tightening spring is arranged in the pre-tightening spring mounting holes. The top end of the pre-tightening spring is mounted with a motor seat. A spring pressing column cooperating with the pre-tightening spring is arranged on the lower surface of the motor seat. A paired pre-tightening adjusting bolt and pre-tightening adjusting nut are arranged through the central positions of the base, the pre-tightening spring mounting seat and the motor seat; A motor mounting groove is arranged at the top end of the motor seat, and a piezoelectric motor main body is mounted in the motor mounting groove. The piezoelectric motor main body is fixed through the cooperation of a pressing plate and the motor seat; Bearing seats are mounted on both sides of the base, bearings are mounted on the bearing seats, and a turntable is mounted in the bearings. The output end of the turntable is connected to the adjusting assembly.

5. The amphibious biomimetic manta ray robot with adjustable buoyancy based on piezoelectric drive according to claim 4, wherein: Piezoelectric ceramics are arranged below the middle beam, on the side of the front beam and on the side of the rear beam of the piezoelectric motor main body. A driving foot cooperating with the turntable is arranged above the middle beam.

6. The amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive according to claim 1, characterized in that: The adjusting assembly includes a coupling. The output end of the coupling is connected to the input end of a reducer. The output end of the reducer is connected to the head end of a rotating shaft by a set screw. A rotating shaft nut mounting groove is arranged at the tail end of the rotating shaft. A rotating shaft nut is mounted in the rotating shaft nut mounting groove. A rotating shaft bolt is mounted in the rotating shaft nut. The tail end of the rotating shaft bolt is fixedly connected to the lower section of a connecting plate. The upper section of the connecting plate is fixedly connected to the tail end of a piston rod. The head end of the piston rod is fixedly connected to a piston. The piston is located inside a syringe. The syringe is fixed to a middle partition by bolts.

7. The amphibious bionic manta ray robot with adjustable buoyancy based on piezoelectric drive according to claim 6, characterized in that: The coupling, the reducer, the rotating shaft and the rotating shaft bolt are located below the middle partition. The piston rod, the piston and the syringe are located above the middle partition. A reducer upper fixing plate for fixing the reducer and a rotating shaft upper fixing plate for fixing the rotating shaft are arranged below the middle partition; The reducer upper fixing plate and the rotating shaft upper fixing plate cooperate with a reducer lower fixing plate and a rotating shaft lower fixing plate arranged on the ventral carapace.

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