Ultrasonic direct drive type amphibious mobile robot and driving method therefor

Abstract

To disclose an ultrasonic direct drive type amphibious mobile robot and a driving method for the same.SOLUTION: An ultrasonic direct drive type amphibious mobile robot includes an underwater ultrasonic actuator 1 provided at a rear end part of a cabin 5, and a land ultrasonic actuator 2 provided at a bottom end part of the cabin 5. The mobile robot excites vibration in a primary telescopic mode in a thickness direction of a third vibrator by applying a drive voltage to the third vibrator of the underwater ultrasonic actuator 1, generates ultrasonic waves having same frequency in water, generates interaction thrust by ultrasonic waves and water, drives underwater travel of the amphibious mobile robot, applies a drive voltage to a first piezoelectric ceramic sheet and a second piezoelectric ceramic sheet of the land ultrasonic actuator 2 when travelling on a land, thereby exciting each vibration in primary flexural mode of a first vibrator and a second vibrator, and driving the land travel of the amphibious mobile robot.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the technical field of amphibious mobile robots, and more particularly to an ultrasonic direct drive type amphibious mobile robot and a driving method thereof. [Background technology]

[0002] Amphibious mobile robots have the ability to operate in different media, both water and land, and can move freely between these different media. They are widely used in fields such as coastal environmental monitoring, environmental exploration, and unmanned reconnaissance. Their ability to operate in different media allows them to move freely in water and on land, adapting to complex water and land environments. Furthermore, the remote control and navigation capabilities of amphibious mobile robots can reduce risks to humans in dangerous environments and improve the efficiency and safety of coastal operations. However, due to their operating principles, conventional amphibious mobile robots generate noise and air bubbles in the water and surrounding environment during underwater operations. In sensitive environments where quiet operation is required, the noise and air bubbles can make the robot more susceptible to tracking and reduce concealment.

[0003] To meet the needs of various scenarios, several amphibious robots have been developed. For example, Chinese Patent Document CN109017179A proposes an amphibious fire truck for firefighting operations, and Chinese Patent Document CN106394541A proposes an amphibious planing boat. Most conventional amphibious robots are designed based on a propeller, wheelset, and crawler drive system, which offers powerful characteristics such as high speed and high load capacity. However, the output characteristics of the propeller and wheelset make amphibious robots based on this design susceptible to noise and tracking. When a propeller rotates, small air bubbles are formed due to the combined action of the mutual force between the blades and water and the vibration of the blades. The resulting pressure changes in the propeller are converted into low-frequency sound waves, which can cause noise. At the same time, tip vortices can form at the ends of the propeller blades, causing turbulence. In these turbulent and vortex flows, gases in the water mix together to form bubbles, and the turbulence itself also causes noise. Such noise and the traces of operation that appear on the water surface due to air bubbles can also be tracked by the robot, making it difficult to move or work covertly.

[0004] One common method for powering the propeller and wheelset is to use an internal combustion engine powered by gasoline or diesel. While this method offers significant advantages in terms of power output and adaptability to harsh environments, it suffers from the drawbacks of being noisy, polluting the environment, and making it vulnerable to detection when used in fields such as environmental monitoring and unmanned reconnaissance. Another method is to use a battery-powered motor. While this method reduces the noise generated by the amphibious robot's power source, it is difficult to completely suppress the noise caused by the interaction between the propeller and water, and driving traces are left behind. As a result, amphibious robots using conventional drive systems suffer from high noise, high energy consumption, environmental interference, and susceptibility to tracking, limiting their applicability in fields such as reconnaissance.

[0005] For these reasons, conventional amphibious mobile robots use propellers, wheel sets, crawlers, or other drive systems, resulting in problems such as loud operating noise, obvious driving traces, impacting environmental exploration, and potentially revealing the vehicle. Furthermore, the use of propellers as underwater drive systems is prone to the generation of air bubble zones at the rear, and propeller cavitation increases repair and maintenance costs. Furthermore, when a multi-stage transmission structure coupled with an internal combustion engine or motor is used, the multi-stage transmission from the energy source to the drive end results in significant energy loss, low efficiency in converting the rotational power of the propeller into forward power for the vehicle, significant power loss, and the large volume and mass of the drive structure. Summary of the Invention

[0006] To solve the above problems, the present invention proposes an ultrasonic direct drive amphibious mobile robot and its driving method, which drives the robot to move underwater or on land by exciting the primary expansion and contraction mode in the thickness direction of the vibrating body of an underwater ultrasonic actuator and the primary bending mode of the vibrating body of a land ultrasonic actuator, thereby solving the problems of conventional amphibious robots, such as the loud operating noise and obvious driving traces.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions. In a first aspect, the present invention provides a watercraft comprising a cabin, a drive control circuit provided within the cabin, an underwater ultrasonic actuator provided at the rear end of the cabin, and a land ultrasonic actuator provided at the bottom end of the cabin, wherein the underwater ultrasonic actuator and the land ultrasonic actuator are both electrically connected to the drive control circuit; the land ultrasonic actuator includes a first case, and a first vibrating body and a second vibrating body provided on both sides of the first case, the first vibrating body and the second vibrating body are provided with a first piezoelectric ceramic sheet and a second piezoelectric ceramic sheet, respectively, and the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet are both electrically connected to a drive control circuit; the underwater ultrasonic actuator includes a second case and a third vibrator provided in the second case; the drive control circuit applies a drive voltage to the third vibrating body to excite vibration in a primary expansion / contraction mode in the thickness direction of the third vibrating body, generate ultrasonic waves of the same frequency in water, generate a thrust due to interaction between the ultrasonic waves and water, and drive the amphibious mobile robot to travel underwater; The drive control circuit applies a drive voltage to the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet to excite vibrations in the primary deflection mode of the first vibrating body and the second vibrating body, respectively, thereby providing an ultrasonic direct drive amphibious mobile robot that is used to drive the amphibious mobile robot to move on land.

[0008] In an optional embodiment, an underwater ultrasonic actuator is provided on each side of the rear end of the cabin, and drive voltages of different magnitudes are applied to the third vibrators of the two underwater ultrasonic actuators by a drive control circuit, and drive voltages of different magnitudes are applied to the first vibrator and the second vibrator by a drive control circuit, thereby controlling acceleration / deceleration and differential turning movements underwater or on land in a differential manner.

[0009] In an alternative embodiment, the movement direction of the amphibious mobile robot and the thrust of the underwater ultrasonic actuator and the land ultrasonic actuator are controlled in a closed loop, specifically by setting a target movement direction angle and a target thrust, collecting the current movement direction angle and actuator thrust, feeding back the current movement direction angle and acceleration, obtaining an error angle from the target movement direction angle and the current movement direction angle, calculating acceleration from the error angle using a direction PID controller, obtaining the error acceleration from the fed-back acceleration, and then feedback-controlling the thrust generated by the underwater ultrasonic actuator and the land ultrasonic actuator using a thrust PID controller.

[0010] As an optional embodiment, a battery pack for outputting a power supply is further provided within the cabin, and the battery pack is connected to a drive control circuit, which converts the output of the power supply into a drive voltage and applies it to the third vibrating body, or the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet.

[0011] In an alternative embodiment, the first and second piezoelectric ceramic sheets are provided with magnetically attractive contacts, and the first and second piezoelectric ceramic sheets are electrically connected to a drive control circuit by the magnetically attractive contacts.

[0012] In an alternative embodiment, the third vibrating body is electrically connected to a drive control circuit by a magnetically attractive contact, and a vibration-damping rubber ring is provided on the third vibrating body.

[0013] In an alternative embodiment, the third vibrating body is a piezoelectric ceramic that serves as both an excitation source and a vibrating body.

[0014] In an alternative embodiment, the third vibrating body is a cylindrical sheet-shaped piezoelectric ceramic or an arc-shaped piezoelectric ceramic.

[0015] In an alternative embodiment, the driving frequency band of the underwater ultrasonic actuator is a frequency band of the MHz level, and the driving frequency band of the land ultrasonic actuator is a frequency band of the KHz level.

[0016] As an optional embodiment, the land-based ultrasonic actuator further includes a fixed cover, wherein fixed rods are provided at two nodes in the primary deflection mode of the first and second vibrating bodies, and the first case is provided with a groove with an open upper end in which the fixed rod is positioned, and this groove forms a closed groove with the fixed cover, and the fixed rod and the first and second vibrating bodies are tightly fitted, and the fixed rod and the first case and fixed cover are loosely fitted.

[0017] In an alternative embodiment, the drive control circuit is further adapted to receive a control command and select different operating modes in response to the control command. The operating modes include an automatic mode, a surface mode, and a land mode. In the different modes, a water level sensor detects whether the amphibious mobile robot is in water, and if so, the underwater ultrasonic actuator is activated, and if not, the land ultrasonic actuator is activated. In the surface mode, if the water level sensor detects that the amphibious mobile robot is not in water, a no-surface error command is returned. In the land mode, if the water level sensor detects that the amphibious mobile robot is in water, a no-land error command is returned.

[0018] In a second aspect, the present invention provides a method for producing a method of manufacturing a semiconductor device comprising: a step of applying a drive voltage to a third vibrating body of the underwater ultrasonic actuator during underwater travel, thereby exciting vibration in a primary expansion / contraction mode in the thickness direction of the third vibrating body, generating ultrasonic waves of the same frequency underwater, generating a thrust due to interaction between the ultrasonic waves and water, and driving the amphibious mobile robot to travel underwater; and applying a drive voltage to the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet of the land-use ultrasonic actuator when the robot is moving on land, thereby exciting vibrations in the first deflection mode of the first vibrating body and the second vibrating body, respectively, and thereby driving the robot to move on land.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides an ultrasonic direct-drive amphibious mobile robot and its driving method, which drives the robot to move underwater or on land by exciting the primary expansion / contraction mode in the thickness direction of the vibrating body of an underwater ultrasonic actuator and the primary bending mode of the vibrating body of a land-based ultrasonic actuator. In water, high-frequency ultrasonic waves from the underwater ultrasonic actuator propagate backward through the water and are highly directional. The ultrasonic waves interact with the water, generating a thrust, which drives the robot to move forward. During movement, the vibrating body of the underwater ultrasonic actuator does not undergo large mechanical displacements, and the ultrasonic waves exert a clear thrust on the water flow, so no bubbles are generated in the water, the thrust is generated in a laminar flow, and no obvious traces are left on the water surface. Furthermore, the ultrasonic waves form a sound field underwater using water as a medium, so no ripples are created on the water surface. On land, the ultrasonic frequency far exceeds the human audible frequency range, so there is no loud noise, only slight friction noise. This solves the problems of conventional amphibious robots, such as loud operating noise and obvious operating traces, and greatly reduces operating noise, enabling amphibious robots to operate without noise or traces, which has potential for application in fields such as environmental monitoring and unmanned reconnaissance for amphibious robots.

[0020] The present invention adopts a method of direct ultrasonic drive on land and in water, so that when operating underwater and on land, energy is converted into a flow such as electrical energy-vibration-sound wave-kinetic energy, and only a small amount of energy is dissipated as heat energy, so there is no large amount of energy loss, resulting in high energy conversion efficiency and low power loss.

[0021] The underwater ultrasonic actuator and the land ultrasonic actuator of the present invention have extremely small mechanical displacements at the nm and μm level, so the wear of the underwater ultrasonic actuator is extremely small and there is no generation of bubbles or cavitation. Furthermore, although the land ultrasonic actuator does rub against the ground, the vibrating body that comes into contact with the ground is made of steel, so the wear rate is slow, reducing the repair and maintenance costs of the robot.

[0022] Advantages of additional aspects of the present invention will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention.

[0023] The drawings constituting a part of this invention are intended to provide a further understanding of the invention, and the illustrative embodiments of the invention and the description thereof are intended to interpret the invention and are not intended to unduly limit the invention. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a structural schematic diagram of an ultrasonic direct drive amphibious mobile robot provided in Example 1 of the present invention; FIG. [Figure 2] 1 is a structural schematic diagram of an underwater ultrasonic actuator provided in Example 1 of the present invention. FIG. [Figure 3] 1 is a schematic diagram of the vibration mode of the piezoelectric ceramic of the underwater ultrasonic actuator provided in Example 1 of the present invention. FIG. [Figure 4] FIG. 2 is a finite element simulation diagram of acoustic-fluid coupling provided in Example 1 of the present invention. [Figure 5] 1 is a structural schematic diagram of a land-use ultrasonic actuator provided in Example 1 of the present invention. FIG. [Figure 6] 2 is a schematic diagram of a vibration mode of a vibrator of the ultrasonic actuator for land use provided in Example 1 of the present invention. FIG. [Figure 7] 1 is a flowchart of the closed-loop control of the movement direction and thrust of the robot provided in the first embodiment of the present invention. [Figure 8] 1 is a flowchart of a control policy of a robot provided in the first embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] In the following the invention will be further explained in connection with the drawings and examples.

[0026] It should be noted that the following detailed description is for illustrative purposes only and is intended to further explain the present invention. Unless otherwise explained, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0027] It should be noted that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular is intended to include the plural, and the terminology "comprise" and / or "include" and any variations thereof is intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus comprising a series of steps or units is not limited to the explicitly listed steps or units, but may include other steps or units not explicitly listed or inherent to those processes, methods, products, or apparatus.

[0028] Unless contradictory, the embodiments of the present invention and the technical features in the embodiments may be combined with each other.

[0029] Example 1 This embodiment provides an ultrasonic direct drive amphibious mobile robot, and as shown in FIG. 1, it includes a cabin 5, a drive control circuit 4 provided in the cabin 5, an underwater ultrasonic actuator 1 provided at the rear end of the cabin 5, and a land ultrasonic actuator 2 provided at the bottom end of the cabin 5, and the underwater ultrasonic actuator 1 and the land ultrasonic actuator 2 are both electrically connected to the drive control circuit 4, The land ultrasonic actuator 2 includes a first case 28, a first vibrating body 21 and a second vibrating body 24 provided on both sides of the first case 28, a first piezoelectric ceramic sheet 22 and a second piezoelectric ceramic sheet 25 provided on the first vibrating body 21 and the second vibrating body 24, respectively, and the first piezoelectric ceramic sheet 22 and the second piezoelectric ceramic sheet 25 are both electrically connected to a drive control circuit 4, The underwater ultrasonic actuator 1 includes a second case 13 and a third vibrating body 11 provided in the second case 13, The drive control circuit 4 applies a drive voltage to the third vibrating body 11 to excite vibration in a primary expansion / contraction mode in the thickness direction of the third vibrating body 11, and also generates ultrasonic waves of the same frequency in water, generating a thrust due to the interaction between the ultrasonic waves and water, thereby driving the amphibious mobile robot to travel underwater; The drive control circuit 4 is used to apply a drive voltage to the first piezoelectric ceramic sheet 22 and the second piezoelectric ceramic sheet 25, thereby exciting vibrations in the primary deflection mode of the first vibrating body 21 and the second vibrating body 24, respectively, and driving the amphibious mobile robot to move on land.

[0030] In this embodiment, an underwater ultrasonic actuator 1 is provided on each side of the rear end of the cabin 5 to provide thrust for the amphibious mobile robot to travel underwater, and operations such as acceleration / deceleration and differential turning are controlled by adjusting the amplitude of the drive voltage applied to the third vibrating body 11 of each of the two underwater ultrasonic actuators 1 using a drive control circuit 4.

[0031] Specifically, the amplitude of the drive voltage applied to the underwater ultrasonic actuator is controlled by an operational amplifier, and the higher the drive voltage, the greater the thrust provided by the underwater ultrasonic actuator. By supplying drive voltages of different magnitudes to the underwater ultrasonic actuators on both the left and right sides, operations such as acceleration / deceleration and differential turning are achieved differentially. At the same time, the direction of movement and the thrust generated by the underwater ultrasonic actuators are controlled in a closed loop by an acceleration sensor, thereby achieving accurate robot movement.

[0032] At the bottom end of the cabin 5, a land ultrasonic actuator 2 is provided to provide thrust for the amphibious mobile robot to move on land.

[0033] Both the underwater ultrasonic actuator 1 and the land ultrasonic actuator 2 are connected to the cabin 5 with screws, and are electrically connected to the drive control circuit 4 by waterproof cables and magnetic contacts.

[0034] The drive control circuit 4 includes a drive circuit board 41 and a main control circuit board 42. The drive circuit board is a high-voltage drive circuit board, and the drive control circuit 4 uses a double circuit board for the following purposes: 1) To separate high-voltage signals and low-voltage signals to avoid interference; 2) Because the space inside the robot is limited, the double board arrangement reduces the area of ​​a single circuit board, thereby meeting the design requirements of a small overall robot volume and a compact structure.

[0035] The cabin 5 forms an enclosed space together with the magnetically adsorbed canopy 6, and a battery pack 3 for outputting a predetermined power supply is further provided inside the cabin 5. The battery pack 3 is connected to a drive control circuit 4, which converts the output of the power supply into a drive voltage of a predetermined magnitude and frequency and applies it to the third vibrating body 11 of the underwater ultrasonic actuator 1 and the first and second piezoelectric ceramic sheets of the land ultrasonic actuator 2, thereby exciting the vibrating bodies of the underwater ultrasonic actuator 1 and the land ultrasonic actuator 2, thereby controlling the vibration mode of the vibrating bodies.

[0036] 2, the underwater ultrasonic actuator 1 includes a second case 13, a sealing lid 14, and a third vibrating body 11 provided in the internal space formed by the second case 13 and the sealing lid 14, the third vibrating body 11 being electrically connected to the drive control circuit 4, and a vibration-damping rubber ring 12 being provided on the third vibrating body 11. Here, the third vibrating body 11 is also a piezoelectric ceramic sheet, which functions as both an excitation source and a vibrating body, and excites a primary expansion / contraction mode in the thickness direction of the piezoelectric ceramic sheet itself.

[0037] Current amphibious mobile robots use new drive systems other than propellers, such as traveling wave drive using flexible wave fins as designed in patent document CN113771566A, jet drive using a piezoelectric pump driven by piezoelectric ceramics as proposed in patent document CN113772053B, and drive using underwater thrust generated by vibration and fluid-structure coupling.

[0038] The amphibious mobile robot of this embodiment is also driven by a piezoelectric ceramic sheet. However, in this embodiment, high-frequency ultrasonic waves in the MHz frequency range are generated in water by the piezoelectric ceramic, and thrust is generated directly into the water based on the physical phenomenon that ultrasonic waves in this frequency range easily propagate from the actuator (solid) into the water (liquid). This method is fundamentally different from the drive method using fins and a pump described in the previous example.

[0039] In this embodiment, the third vibrating body 11 is a cylindrical sheet of piezoelectric ceramic, as shown in Fig. 3, which operates in a primary expansion / contraction mode in the thickness direction and has an operating frequency of 1.65 MHz. When an excitation voltage of the same frequency is applied to it, it excites the piezoelectric ceramic to vibrate in that mode and generates ultrasonic waves of the same frequency in water. In that frequency band, the ultrasonic waves have high directionality, a strong thrust, and a large thrust can be generated.

[0040] As an alternative embodiment, the third vibrating body 11 may employ an arc-shaped piezoelectric ceramic so as to concentrate ultrasonic energy.

[0041] As shown in Figure 4, in this example, an acoustic-fluid coupled simulation of underwater ultrasound in this frequency band was performed. The image on the left is a sound pressure level image, which shows that the sound pressure in the center is clearly higher than the sound pressure on both sides, indicating high directionality of the sound waves. The image on the right is a fluid streamline image, which shows that sound waves in this frequency band generate a strong thrust force on the water, creating a fast-moving water flow behind them and two vortices.

[0042] In this embodiment, as shown in FIG. 5, the land ultrasonic actuator 2 includes a first vibrating body 21, a first piezoelectric ceramic sheet 22, a fixed rod 23, a second vibrating body 24, a second piezoelectric ceramic sheet 25, a fixed cover 26, a magnetic attraction contact 27, and a first case 28.

[0043] The bottom of the first case 28 is open, and the legs of the vibrating body are in direct contact with the ground to achieve driving, and a first vibrating body 21 and a second vibrating body 24 are provided on both sides of the first case 28, a first piezoelectric ceramic sheet 22 is provided on the first vibrating body 21, and a second piezoelectric ceramic sheet 25 is provided on the second vibrating body 24, and the first vibrating body 21 and the second vibrating body 24 are used to drive movement on both the left and right sides, respectively.

[0044] The first piezoelectric ceramic sheet 22 and the second piezoelectric ceramic sheet 25 are provided with magnetically attractive contacts 27 , and the first piezoelectric ceramic sheet 22 and the second piezoelectric ceramic sheet 25 are electrically connected to the drive control circuit 4 by the magnetically attractive contacts 27 .

[0045] To ensure that the vibrations of the first vibrating body 21 and the second vibrating body 24 are not transmitted to the first case 28, fixed rods 23 are fixed to two nodes in the primary bending mode of the first vibrating body 21 and the second vibrating body 24. The fixed rod 23 at one node penetrates the first vibrating body 21 and the second vibrating body 24, ensuring that the linear displacement of the fixed rod 23 is extremely small but that a constant rotational displacement is maintained.

[0046] The first case 28 is provided with a groove with an open top in which the fixed rod 23 is placed, and this groove forms a closed groove together with a part of the fixed cover 26. When assembled, the fixed rod 23 is tightly fitted with the first vibrating body 21 and the second vibrating body 24, and is loosely fitted with the first case 28 and the fixed cover 26, providing space for rotation of the fixed rod 23 and significantly reducing the transmission of vibration of the vibrating body to the case, while also ensuring the effect of external fixed boundary conditions on the vibration frequency of the first bending mode of the first vibrating body 21 and the second vibrating body 24.

[0047] In this embodiment, the land-use actuator also employs an ultrasonic drive scheme, with a drive frequency band in the kHz range. The drive principle of the land-use ultrasonic actuator differs from that of the underwater ultrasonic actuator. The piezoelectric ceramic in the underwater ultrasonic actuator functions as both the excitation source and the vibrating body, exciting the primary expansion / contraction mode in the thickness direction of the piezoelectric ceramic itself. In contrast, as shown in Figure 6, the land-use ultrasonic actuator uses a thin piezoelectric ceramic sheet only as the excitation source, which excites the primary bending mode of the first and second steel vibrating bodies 21 and 24 at a frequency of 48.5 kHz. In this mode, the driving capacity of the land-use ultrasonic actuator is generated by the directionality of the feet when they touch the ground.

[0048] In this embodiment, the drive voltage amplitude for the vibrators on both the left and right sides of the land-use ultrasonic actuator is adjusted and controlled by the drive control circuit 4, so that the land-use ultrasonic actuator can realize movements such as acceleration / deceleration and differential turning.

[0049] Specifically, the amplitude of the drive voltage applied to the land-based ultrasonic actuator is controlled by an operational amplifier, and the higher the drive voltage, the greater the thrust provided by the land-based ultrasonic actuator. By supplying drive voltages of different magnitudes to the vibrators on both the left and right sides, operations such as acceleration / deceleration and differential turning are realized in a differential manner. At the same time, the direction of movement and the thrust generated by the land-based ultrasonic actuator are controlled in a closed loop by an acceleration sensor, thereby achieving accurate robot movement.

[0050] In this embodiment, the closed-loop control flow for the robot's motion direction and thrust is as shown in FIG. 7. Specifically, a target angle and target thrust are set, the current output angle and output thrust are collected by an acceleration sensor, the angle and linear acceleration are fed back, an error angle is obtained from the target angle and the fed-back angle, an acceleration is calculated from the error angle by a direction PID controller, and the error acceleration is obtained from the fed-back acceleration. The thrust generated by the actuator is then feedback-controlled by a thrust PID controller, and accurate control of the motion direction and thrust is achieved by a cascade PID control algorithm for direction and thrust.

[0051] In this embodiment, the drive control circuit is integrated with the robot's wireless communication module, which receives control commands from the remote control handle. As shown in Figure 8, upon receiving the commands, the wireless communication module interprets the commands and selects one of the different operating modes. The operating modes include automatic mode, surface mode, and land mode. In the different modes, a water level sensor detects whether the robot is underwater. If it is underwater, the underwater ultrasonic actuator is activated, and if not, the land ultrasonic actuator is activated. In the surface mode, if the water level sensor determines that the robot is not underwater, a non-surface error command is returned. In the land mode, if the water level sensor determines that the robot is underwater, a non-land error command is returned.

[0052] It is understood that the size and shape of the vibrating body and the number of piezoelectric ceramics in the land ultrasonic actuator may be changed, and other modes may be applied according to the actual situation.

[0053] This embodiment provides an ultrasonic direct drive amphibious mobile robot, which uses ultrasonic transducers to directly interact with two media, water and land, and measures 117.78 x 105.24 x 56.79 mm. 3A small prototype has been developed, weighing 234.36g. It employs wireless communication technology and can move in both water and land, achieving silent and traceless underwater movement. The prototype can achieve a maximum speed of 154.66mm / s on land and 54.64mm / s underwater, with a maximum bottom load of 1357.66g, or 5.79 times its own weight. Additionally, the unique advantages of ultrasonic transducer drive allow it to achieve a minimum step distance of 6.5um when operating on land, enabling it to achieve high-precision adjustment of position, attitude, and viewing angle in special reconnaissance environments.

[0054] Example 2 This embodiment provides a driving method for the ultrasonic direct drive amphibious mobile robot described in embodiment 1, a step of applying a drive voltage to a third vibrating body of the underwater ultrasonic actuator during underwater travel, thereby exciting vibration in a primary expansion / contraction mode in the thickness direction of the third vibrating body, generating ultrasonic waves of the same frequency underwater, generating a thrust due to interaction between the ultrasonic waves and water, and driving the amphibious mobile robot to travel underwater; and applying a drive voltage to the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet of the land ultrasonic actuator during land movement, thereby exciting vibrations in the first vibration body and the second vibration body in the primary deflection mode, respectively, thereby driving the amphibious mobile robot to move on land.

[0055] Although the specific embodiments of the present invention have been described above with reference to the drawings, they are not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications and variations that can be made based on the technical solutions of the present invention without any creative effort are also included in the scope of protection of the present invention. [Explanation of symbols]

[0056] 1 Underwater ultrasonic actuator 2. Ultrasonic actuator for land use 3 Battery pack 4. Drive control circuit 5 Cabins 6 Magnetic Canopy 11 Third vibrator 12 Anti-vibration rubber ring 13 Second Case 14 Sealing lid 21 First vibrating body 22 First piezoelectric ceramic sheet 23 Fixed rod 24 Second vibrator 25 Second piezoelectric ceramic sheet 26 Fixed lid 27 Magnetic contact 28 Case 1 41 Drive circuit board 42 Main control circuit board.

Claims

1. The invention comprises a cabin, a drive control circuit provided within the cabin, an underwater ultrasonic actuator provided at the rear end of the cabin, and a land ultrasonic actuator provided at the bottom end of the cabin, wherein the underwater ultrasonic actuator and the land ultrasonic actuator are both electrically connected to the drive control circuit; The land ultrasonic actuator includes a first case, and a first vibrating body and a second vibrating body provided on both sides of the first case, the first vibrating body and the second vibrating body are provided with a first piezoelectric ceramic sheet and a second piezoelectric ceramic sheet, respectively, and the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet are both electrically connected to a drive control circuit, the underwater ultrasonic actuator includes a second case and a third vibrator provided in the second case, the drive control circuit applies a drive voltage to the third vibrating body to excite vibration in a primary expansion / contraction mode in the thickness direction of the third vibrating body, generate ultrasonic waves of the same frequency in water, generate a thrust due to interaction between the ultrasonic waves and water, and drive the amphibious mobile robot to travel underwater; The drive control circuit is used to apply a drive voltage to the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet to excite vibrations in the primary deflection mode of the first vibrating body and the second vibrating body, respectively, thereby driving the amphibious mobile robot to move on land.

2. 2. The ultrasonic direct drive amphibious mobile robot according to claim 1, wherein an underwater ultrasonic actuator is provided on each side of the rear end of the cabin, and drive voltages of different magnitudes are applied to the third vibrators of the two underwater ultrasonic actuators by a drive control circuit, and drive voltages of different magnitudes are applied to the first vibrator and the second vibrator by a drive control circuit, thereby controlling acceleration / deceleration and differential turning motion underwater or on land in a differential manner.

3. 3. The ultrasonic direct drive amphibious mobile robot of claim 2, wherein the direction of movement of the amphibious mobile robot and the thrust of the underwater ultrasonic actuator and the land ultrasonic actuator are controlled in a closed loop, specifically by setting a target direction of movement angle and a target thrust, collecting a current direction of movement angle and actuator thrust, and feeding back the current direction of movement angle and acceleration, obtaining an error angle from the target direction of movement angle and the current direction of movement angle, calculating acceleration from the error angle using a direction PID controller, obtaining the error acceleration from the fed-back acceleration, and then feedback-controlling the thrust generated by the underwater ultrasonic actuator and the land ultrasonic actuator using a thrust PID controller.

4. 2. The ultrasonic direct drive amphibious mobile robot of claim 1, further comprising a battery pack for outputting a power supply, the battery pack being connected to a drive control circuit, the drive control circuit converting the output of the power supply into a drive voltage and applying it to the third vibrator or the first and second piezoelectric ceramic sheets.

5. the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet are provided with magnetically attracting contacts, and the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet are electrically connected to a drive control circuit by the magnetically attracting contacts; the third vibrator is electrically connected to a drive control circuit by a magnetic attraction contact, and the third vibrator is provided with a vibration-damping rubber ring; 2. The ultrasonic direct drive amphibious mobile robot according to claim 1, wherein the third vibrator is a piezoelectric ceramic that functions as both an excitation source and a vibrator.

6. 6. The ultrasonic direct drive amphibious mobile robot according to claim 5, wherein the third vibrator is a cylindrical sheet-shaped piezoelectric ceramic or an arc-shaped piezoelectric ceramic.

7. the driving frequency band of the underwater ultrasonic actuator is a frequency band of the MHz level, 2. The ultrasonic direct drive amphibious mobile robot according to claim 1, wherein the driving frequency band of the land ultrasonic actuator is a frequency band of the kHz level.

8. 2. The ultrasonic direct drive amphibious mobile robot of claim 1, wherein the land ultrasonic actuator further includes a fixed cover, wherein fixed rods are provided at two nodes in the primary deflection mode of the first and second vibrating bodies, and the first case has a groove with an open upper end in which the fixed rod is disposed, the groove forming a closed groove with the fixed cover, and the fixed rod and the first and second vibrating bodies are tightly fitted, and the fixed rod and the first case and fixed cover are loosely fitted.

9. 2. The ultrasonic direct drive amphibious mobile robot of claim 1, wherein the drive control circuit is further used to receive control commands and select different operating modes according to the control commands, the operating modes including an automatic mode, a surface mode, and a land mode, and in the different modes, a water level sensor detects whether the amphibious mobile robot is in water, and if so, the underwater ultrasonic actuators are activated, and if not, the land ultrasonic actuators are activated; in the surface mode, if the water level sensor detects that the amphibious mobile robot is not in water, a non-surface error command is returned; and in the land mode, if the water level sensor detects that the amphibious mobile robot is in water, a non-land error command is returned.

10. a step of applying a drive voltage to a third vibrator of the underwater ultrasonic actuator during underwater travel, thereby exciting vibration in a primary expansion / contraction mode in the thickness direction of the third vibrator, generating ultrasonic waves of the same frequency underwater, generating a thrust due to interaction between the ultrasonic waves and water, and driving the amphibious mobile robot to travel underwater; and applying a drive voltage to the first and second piezoelectric ceramic sheets of the ultrasonic actuator during land movement to excite vibrations in the primary deflection mode of the first and second vibrating bodies, respectively, thereby driving the amphibious mobile robot to move on land.

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