A piezoelectric driven external pipeline climbing robot and a driving method thereof

Abstract

The present invention discloses a piezoelectric driven external pipeline climbing robot and a driving method thereof, and relates to the technical field of pipeline robots. The robot comprises a transducer unit, the transducer unit comprises a vibration mechanism and a crawling mechanism, the vibration mechanism comprises a vibrating body and a piezoelectric ceramic sheet, a plurality of piezoelectric ceramic sheets are arranged on the upper surface of the vibrating body, a crawling mechanism is arranged on the lower surface of the vibrating body, the crawling mechanism comprises a plurality of crawling teeth, and an excitation voltage is applied to the piezoelectric ceramic sheet to excite the vibration of the vibrating body, and further drive the crawling teeth to move relative to the ground, thereby realizing the climbing process of the robot. The present invention realizes the high speed, rapid response and high positioning accuracy of the robot in the pipeline by adopting piezoelectric driving technology.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline robots, and in particular to a piezoelectric driven external pipeline climbing robot and a driving method thereof. Background Art

[0002] Small diameter metal or PE pipes are widely used in modern industry and urban construction due to their light weight, corrosion resistance, and high pressure resistance. These pipes are commonly used in water supply, drainage, gas transmission, chemical pipelines, agricultural irrigation, and cable protection. They not only improve the transmission efficiency, but also reduce maintenance costs and potential leakage risks due to their good sealing and durability. However, as the service time increases, even high-quality pipes may experience performance degradation due to environmental factors, material aging, or construction damage. Regular testing and inspection are essential to ensure the safe operation of pipeline systems. It can detect potential problems in time, such as corrosion, cracks, blockages, or other structural damage, thereby avoiding possible serious consequences such as leakage, explosion, or service interruption. In view of this, the research on external pipeline climbing robots is particularly important. These robots can move along the pipeline automatically or semi-automatically, using built-in sensors and cameras to conduct a comprehensive inspection of the pipeline. Compared with traditional inspection methods, external pipeline climbing robots can perform tasks more efficiently and safely, especially in difficult-to-reach or dangerous environments. They can reduce labor costs, reduce operational risks, and provide more accurate inspection data.

[0003] At present, there are many types of external pipeline climbing robots, which can be divided into rolling type, clamping type, bionic type and adsorption type according to the clamping method. However, adsorption type robots usually rely on vacuum adsorption or magnetic adsorption, which limits their use environment. Wheeled robots are mainly designed for cylindrical climbing poles and have weak climbing ability for rectangular or other polygonal surfaces. Gripping-foot robots require the use of larger motors and complex transmission mechanisms to achieve sufficient load capacity.

[0004] Based on the shortcomings of the above-mentioned robots, piezoelectric-driven robots came into being. Compared with traditional motors and pneumatic components, the piezoelectric drive has the characteristics of high efficiency, high precision, power-off self-locking, fast response, low noise, and anti-electromagnetic interference, which enables the robot to perform precise position and speed control, which is crucial to improving the accuracy and safety of detection tasks. The pressure point drive transmission is simple and more efficient, and can achieve a more compact and simple structural design, which is convenient for flexible operation in narrow pipeline spaces, reduces maintenance costs and avoids electromagnetic interference. In addition, the piezoelectric drive can achieve a variety of motion modes, including bending and torsion, which provides great flexibility for the robot to move in complex pipeline structures. In view of this, the piezoelectric-driven small external pipeline climbing robot has shown great advantages in improving pipeline detection efficiency, reducing maintenance costs, and enhancing the robot's environmental adaptability.

[0005] However, the existing piezoelectric driven robots are single and can only be used for pipes of specific sizes and shapes, which greatly limits the robot's detection work. Therefore, there is an urgent need for a piezoelectric driven robot that can adapt to pipes of various sizes and shapes and has strong stability. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a piezoelectric driven external pipeline climbing robot and a driving method thereof, which realizes high speed, fast response and high positioning accuracy of the robot in the pipeline by adopting piezoelectric driving technology. The design of the crescent-shaped notched climbing teeth and the elastic clamping structure greatly improves the robot's adaptability to different pipeline shapes and sizes.

[0007] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0008] A first aspect of the present invention provides a piezoelectric driven outer pipe climbing robot, comprising a transducer unit,

[0009] The transducer unit includes a vibration mechanism and a crawling mechanism. The vibration mechanism includes a vibrating body and a piezoelectric ceramic sheet. A plurality of piezoelectric ceramic sheets are arranged on the upper surface of the vibrating body, and a crawling mechanism is arranged on the lower surface of the vibrating body. The crawling mechanism includes a plurality of crawling teeth. The crawling teeth are spaced at a set distance. By applying an excitation voltage to the piezoelectric ceramic sheet, the vibration of the vibrating body is stimulated, and the crawling teeth are further driven to move relative to the ground, thereby realizing the climbing process of the robot.

[0010] Furthermore, the transducer unit also includes mounting rollers, which include front rollers and rear rollers, which are respectively mounted on the front end and the rear end of the vibrating body, and the mounting rollers are used to fix the clamping mechanism.

[0011] Furthermore, it also includes a clamping mechanism, which includes two upper and lower fixed supporting plates, on which a transducer unit is respectively installed through mounting rollers, and the two fixed supporting plates are connected by screws, which are fixed by springs and nuts.

[0012] Furthermore, the vibrating body is made of alumina material.

[0013] Furthermore, two longitudinal vibration piezoelectric ceramic sheets of the same specification are adhered to the upper surface of the vibrator via a coupling agent.

[0014] Furthermore, the longitudinally vibrating piezoelectric ceramic sheet is polarized along the thickness direction, and the two piezoelectric ceramic sheets are arranged in the same direction.

[0015] Furthermore, the creeping teeth are in the shape of a triangular prism, wherein one rectangular surface is connected to the lower surface of the vibrating body, and an arc edge structure is adopted in the middle of the edge contacting the ground.

[0016] A second aspect of the present invention provides a driving method for the piezoelectric driven outer pipe climbing robot according to the first aspect, comprising the following steps:

[0017] Applying an excitation voltage of the same amplitude and frequency to the piezoelectric ceramic piece to excite the vibrating body to vibrate;

[0018] According to the task requirements, the phase difference of the excitation voltage between the piezoelectric ceramic sheets is adjusted so that the vibrating body drives the creeping gear to move relative to the ground;

[0019] After use, turn off the excitation voltage and reset the transducer unit.

[0020] Furthermore, when the phases of the two excitation signals differ by 180° from each other, the front piezoelectric ceramic sheet is elongated in the length direction and the rear piezoelectric ceramic sheet is shortened in the length direction. When the front piezoelectric ceramic sheet is shortened in the length direction, the rear piezoelectric ceramic sheet is elongated in the length direction. Under the excitation of the two piezoelectric ceramic sheets, the vibrating body is promoted to complete the second-order bending vibration, and at the same time, the creeping teeth are driven to move relative to the ground, causing the transducer unit to move backward.

[0021] Furthermore, when the phase difference is 0°, the piezoelectric ceramic sheets on the front and rear sides move in the same manner, promoting the vibrator to complete the third-order bending vibration, while driving the creeping teeth to move relative to the ground, causing the transducer unit to move forward.

[0022] One or more of the above technical solutions have the following beneficial effects:

[0023] The present invention discloses a piezoelectric driven external pipeline climbing robot and a driving method thereof. Aiming at the problems of the existing external pipeline climbing robots, such as large size, low positioning accuracy, and insufficient application scenarios, a piezoelectric driven small external pipeline climbing robot is designed. By adopting the piezoelectric driving technology, the robot can achieve high speed, fast response and high positioning accuracy in the pipeline. This improvement effectively solves the problem of bloated transmission structure in the traditional driving system, significantly reduces the volume of the robot in pipeline climbing, improves its adaptability and control accuracy, and thus meets the precise detection requirements in complex environments. In addition, the same-mode variable-order actuation mode of the variable frequency phase modulation excitation piezoelectric transducer unit is adopted to simplify the robot drive and configuration. This design reduces the errors in the manufacturing and assembly processes, making the robot system simpler and more reliable. This improvement not only improves the controllability of the system, but also simplifies the system integration in multiple application scenarios, greatly improving the application flexibility of the robot in different working environments.

[0024] The present invention adopts a crawling tooth with an arc blade structure similar to a crescent-shaped notch. The designed crescent-shaped notch crawling tooth and the elastic clamping structure greatly improve the robot's adaptability to different pipe shapes and sizes. The crescent-shaped notch crawling tooth can effectively grasp pipes of various shapes such as round pipes or square pipes, while the elastic clamping structure enables the robot to work stably on pipes of different diameters. This design enhances the applicability of the robot, enabling it to work efficiently under a variety of pipeline conditions, thereby broadening its application range and meeting the needs of different pipeline inspection and maintenance tasks.

[0025] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] Figure 1 This is a schematic diagram of the overall structure of the piezoelectric driven external pipe climbing robot in the first embodiment of the present invention;

[0028] Figure 2 Schematic diagram of the arc edge structure of the creeping tooth in the first embodiment of the present invention;

[0029] Figure 3 The same-mode variable-order actuation principle of the transducer unit in the first embodiment of the present invention;

[0030] Figure 4 It is a schematic diagram of the second-order bending vibration in the bidirectional motion vibration mode in the first embodiment of the present invention;

[0031] Figure 5 It is a schematic diagram of the third-order bending vibration in the bidirectional motion vibration mode in the first embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the combination of the transducer unit and the clamping mechanism in the first embodiment of the present invention;

[0033] Among them, 1. vibrating body, 2. piezoelectric ceramic sheet, 3. creeping teeth, 4. mounting rollers, 5. upper transducer unit, 6. lower transducer unit, 7. fixed bearing plate, 8. screws, 9. springs, and 10. nuts. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0035] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or their combinations;

[0036] Embodiment 1:

[0037] Embodiment 1 of the present invention provides a piezoelectric driven external pipeline climbing robot, including a transducer unit and a clamping mechanism, such as Figure 1 As shown, the transducer unit includes a vibration mechanism and a creeping mechanism.

[0038] The vibration mechanism includes a vibration body 1 and a piezoelectric ceramic sheet 2. The vibration body 1 is made of alumina material and can be elastically deformed according to vibration. Specifically, alumina is used as the material, fired and cut into ceramic parts as the vibration body according to size requirements, and the piezoelectric ceramic is pasted on the surface of the alumina ceramic. It can output greater motion displacement, response speed and other motion performances with a smaller driving voltage than the vibration body made of traditional stainless steel materials, which reduces the conditions for generating excitation signals and is more conducive to system integration. A number of piezoelectric ceramic sheets 2 are arranged on the upper surface of the vibration body 1. Specifically, two longitudinal vibration piezoelectric ceramic sheets 2 of the same specification are pasted on the upper surface of the vibration body 1 through a coupling agent. The longitudinal vibration piezoelectric ceramic sheet 2 is polarized along the thickness direction, and the two piezoelectric ceramic sheets 2 are arranged in the same direction. The spatial position of the piezoelectric ceramic sheet satisfies the conditions for the excitation of the second-order and third-order bending vibration modes of the vibrating body 1. The selection of the second-order and third-order bending vibration modes can obtain a larger displacement than the higher-order mode. Because the new material aluminum oxide is selected as the vibrating body 1, the disadvantage of the low resonant frequency of the second-order and third-order bending vibration modes is compensated, thereby achieving better motion performance. The purpose of pasting two piezoelectric ceramics is to make full use of the surface space of the vibrating body 1 and increase the number of piezoelectric ceramic sheets 1 pasted. Compared with one piezoelectric ceramic, two piezoelectric ceramics can excite a larger displacement, thereby optimizing the performance of the micro-climbing robot. If three piezoelectric ceramics are used, on the one hand, the requirements for electrical signals are increased, and the phase difference of the three needs to be more accurately controlled; secondly, due to space limitations, two piezoelectric ceramics have fully utilized the surface space. If the number of piezoelectric ceramics is to be increased, the overall size needs to be increased, which violates the original intention of the micro-robot of the present invention. Therefore, the present invention uses two piezoelectric ceramics to improve the standing wave actuator force and power density, and improve the actuator speed and load performance. In other scenarios, the number of piezoelectric ceramics can be adaptively changed as needed.

[0039] This embodiment adopts a piezoelectric drive design for the external pipeline climbing robot, which achieves high speed, fast response and high positioning accuracy of the robot, and solves the problems of large size, poor adaptability and low control accuracy of the climbing robot caused by the bloated transmission system.

[0040] The lower surface of the vibrating body 1 is provided with a crawling mechanism, which includes a plurality of crawling teeth 3, and the overall design has a prismatic feature, specifically, Figure 2 As shown, the crawling tooth 3 is in the shape of a triangular prism as a whole, in which one of the rectangular faces is connected to the lower surface of the vibrating body. The shape design of the crawling tooth can make a straight line contact between the crawling tooth 3 and the pipe, so that the force of the crawling tooth 3 on the pipe becomes larger. The straight lines on both sides of the crawling tooth 3 are designed to facilitate climbing of rectangular or other polygonal pipes with different diameters. The middle of the edge where the crawling tooth 3 contacts the ground adopts a crescent-shaped arc blade structure to facilitate climbing of circular pipes with different diameters. Specifically, the length of the arc blade structure in the middle of the crawling tooth of this embodiment is set to 8mm. In addition to the arc structure in the middle, there are still straight structures on both sides that can contact the pipe, such as Figure 2 As shown, if the square pipe width is greater than 8mm, there is still good line contact and a good climbing effect. It should be noted that the length of the arc blade structure in the present invention can be customized according to actual conditions.

[0041] The position of the crawling teeth 3 is determined by the driving principle of the ultrasonic actuator, so that the crawling teeth 3 can move in different directions in different vibration modes. The crawling teeth 3 are spaced at a set distance. In this embodiment, two crawling teeth 3 are set. By applying an excitation voltage to the piezoelectric ceramic sheet 2, the vibration body 1 is stimulated to vibrate, which further drives the crawling teeth 3 to move against the ground, thereby realizing the climbing process of the robot. It should be noted that the ground movement in the present invention refers to the movement of the robot on the ground, in pipelines and other scenes.

[0042] When the excitation voltages of the same amplitude and frequency are applied to the piezoelectric ceramic sheets on the upper side of the vibrating body 1 (the excitation signals are sinusoidal signals), longitudinal vibration will be excited on the vibrating body 1. When the phases of the two excitation signals differ by 180°, when the front piezoelectric ceramic sheet is extended in the length direction, the rear piezoelectric ceramic sheet is shortened in the length direction, and when the front piezoelectric ceramic sheet is shortened in the length direction, the rear piezoelectric ceramic sheet is extended in the length direction. Under the excitation of the two, the vibrating body 1 is promoted to complete the second-order bending vibration, and its vibration form is as follows: Figure 4 As shown, the creeping gear 3 is driven to move relative to the ground, causing the actuator to move backward, as shown in FIG. Figure 3 The frequency and phase difference of the two excitation signals are adjusted. When the phase difference is 0°, the piezoelectric ceramic sheets 2 on the front and rear sides move in the same way, promoting the vibration body 1 to complete the third-order bending vibration. The vibration form is shown in FIG. Figure 5 As shown, the crawling teeth 3 are driven to move relative to the ground, so that the actuator moves forward, realizing bidirectional movement and completing the squirrel-like climbing movement characteristics, as shown in FIG. Figure 3 As shown in lines c and d.

[0043] In this embodiment, the goal is to design a small tube-climbing robot with the smallest possible size, and the requirements for electrical signals cannot be too high. The realization frequency of the second and third order bending vibration modes is related to the overall size of the transducer unit. Through experiments, the length of the vibrating body when the driving force to weight ratio is the largest is selected to be 60mm. Subsequently, the corresponding electrical signal is most suitable when the thickness is adjusted to 3mm, and the driving frequency is determined to be 19kHz and 37kHz. Furthermore, the selection of piezoelectric ceramics needs to meet the requirement of amplifying the displacement of the vibrating body to the greatest extent, so the selected piezoelectric ceramics are fitted to the peaks and troughs generated by the vibration, and the size is customized and adjusted as needed. The distance between the two patches depends on the peaks and troughs of the second and third order bending vibration modes of the vibrating body, and the positions where the peaks and troughs are generated are related to the size of the above-mentioned vibrating body, so the patches can be customized and adjusted according to the size of the vibrating body.

[0044] The specifications of the crawling teeth have little to do with the realization of the second and third order bending vibration modes. The crawling teeth act as an output point of displacement and force in the present invention. The size is relatively small and has little effect on the vibration of the vibrating body. Therefore, the size can also be customized and adjusted as needed.

[0045] The present invention uses variable frequency phase modulation to excite the piezoelectric transducer unit in a same-mode variable order actuation mode, which has simple driving and configuration, reduces manufacturing and assembly errors, and easily realizes system integration in multiple application scenarios.

[0046] The transducer unit further includes a mounting roller 4, which includes a front roller and a rear roller, which are respectively mounted at the front end and the rear end of the vibrator, and the mounting roller 4 is used to fix the clamping mechanism. Figure 6 As shown, the clamping mechanism includes two upper and lower fixed bearing plates 7, and a transducer unit is installed on each of the two fixed bearing plates 7 through a mounting roller 4. The two fixed bearing plates are connected by a screw 8, and the screw 8 is fixed by a spring 9 and a nut 10. In this embodiment, the screw is a force screw, the spring is a longitudinal coil spring, and the nut is a force nut.

[0047] Specifically, this embodiment is composed of a pair of transducer units to embrace a micro-tube-climbing robot based on the bionics of squirrel motion. The two transducer units are first connected to the fixed bearing plate 7 through the transducer unit mounting roller 4, and then the upper and lower fixed bearing plates 7 are connected through the force screw. A longitudinal coil spring is connected in series between the upper fixed bearing plate 7 and the force nut, and the two transducer units face each other. When the force nut is screwed, the longitudinal coil spring is squeezed to generate downward pressure on the upper transducer unit 5, and at the same time, there is a reaction force on the force nut, which indirectly acts on the force screw. The force screw generates upward pressure on the lower transducer unit 6, thereby overcoming the influence of its own gravity to clamp the pipe. By controlling the frequency and phase of the excitation signal of the upper transducer unit 5 and the lower transducer unit 6, the bidirectional movement of the micro-tube-climbing robot can be achieved.

[0048] In this embodiment, after adding the clamping mechanism, if the micro-climbing robot is to be moved upward, the upper transducer unit 5 and the lower transducer unit 6 are excited by the piezoelectric ceramics to operate in the third-order bending vibration mode, and the four piezoelectric ceramics have the same phase and frequency; if the micro-climbing robot is to be moved downward, the upper transducer unit 5 and the lower transducer unit 6 are excited by the piezoelectric ceramics to operate in the second-order bending vibration mode, and the two piezoelectric ceramics of the same transducer unit have a phase difference of 180° and the same frequency, while the piezoelectric ceramics at the same position between the two transducer units have the same phase and frequency.

[0049] The present invention improves the adaptability of the external pipeline climbing robot to pipelines of different shapes, such as square pipes / round pipes and different sizes of pipe diameters, by designing a crescent-shaped notched climbing tooth and an elastic clamping structure.

[0050] The micro-tube-climbing piezoelectric robot designed in this embodiment based on the squirrel bionic movement mechanism can maintain basically unchanged movement performance in environments with different tube diameters and different tube types. When the excitation signal is a low voltage of 30V, the micro-piezoelectric robot can reach a movement speed of 0.18m / s and a high load-to-weight ratio of 5.6 times, achieving a breakthrough in the performance of the micro-tube-climbing piezoelectric robot and revealing the application prospects of the micro-tube-climbing piezoelectric robot in various industrial environments.

[0051] Embodiment 2:

[0052] Embodiment 2 of the present invention provides a driving method for the piezoelectric driven outer pipe climbing robot according to embodiment 1, comprising the following steps:

[0053] Step 1: Apply an excitation voltage of the same amplitude and frequency to the piezoelectric ceramic piece to excite the vibrating body to vibrate.

[0054] Step 2: Adjust the phase difference of the excitation voltage between the piezoelectric ceramic sheets according to the task requirements so that the vibrating body drives the creeping teeth to move relative to the ground.

[0055] Step 3: After use, turn off the excitation voltage and reset the transducer unit.

[0056] In step 2, when the phases of the two excitation signals differ by 180°, the front piezoelectric ceramic sheet stretches in the length direction and the rear piezoelectric ceramic sheet shortens in the length direction. When the front piezoelectric ceramic sheet shortens in the length direction, the rear piezoelectric ceramic sheet stretches in the length direction. Under the excitation of the two piezoelectric ceramic sheets, the vibrating body is promoted to complete the second-order bending vibration, and at the same time, the creeping teeth are driven to move relative to the ground, causing the transducer unit to move backward.

[0057] When the phase difference is 0°, the piezoelectric ceramic sheets on the front and rear sides move in the same way, promoting the vibrator to complete the third-order bending vibration, while driving the creeping teeth to move relative to the ground, causing the transducer unit to move forward.

[0058] The steps involved in the above embodiment 2 correspond to those in embodiment 1. For the specific implementation method, please refer to the relevant description part of embodiment 1.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A piezoelectric driven outer pipe climbing robot, characterized in that: The robot comprises a transducer unit, wherein the transducer unit comprises a vibration mechanism and a crawling mechanism, wherein the vibration mechanism comprises a vibrating body and a piezoelectric ceramic sheet, wherein a plurality of piezoelectric ceramic sheets are arranged on the upper surface of the vibrating body, and a crawling mechanism is arranged on the lower surface of the vibrating body, wherein the crawling mechanism comprises a plurality of crawling teeth, wherein the crawling teeth are spaced at a set distance, and an excitation voltage is applied to the piezoelectric ceramic sheet to excite the vibrating body to vibrate, thereby further driving the crawling teeth to move relative to the ground, thereby realizing the climbing process of the robot; Apply excitation voltages of the same amplitude and frequency to the piezoelectric ceramic sheets on the upper side of the vibrating body, and longitudinal vibration is excited on the vibrating body; The transducer unit further comprises a mounting roller, the mounting roller comprising a front roller and a rear roller, which are respectively mounted at the front end and the rear end of the vibrating body, and the mounting roller is used to fix the clamping mechanism; The clamping mechanism also includes an upper and lower fixed bearing plates, each of which is provided with a transducer unit through a mounting roller, the two fixed bearing plates are connected by screws, the screws are fixed by springs and nuts, and the two transducer units face each other; The crawling teeth are in the shape of a triangular prism, in which one rectangular surface is connected to the lower surface of the vibrating body, and an arc blade structure is adopted in the middle of the edge in contact with the ground; the position of the crawling teeth is determined by the driving principle of the ultrasonic actuator.

2. The piezoelectric driven outer pipe climbing robot according to claim 1, characterized in that: The vibrating body is made of aluminum oxide material.

3. The piezoelectric driven outer pipe climbing robot according to claim 1, characterized in that: Two longitudinal vibration piezoelectric ceramic sheets of the same specification are adhered to the upper surface of the vibration body through a coupling agent.

4. The piezoelectric driven outer pipe climbing robot according to claim 3, characterized in that: The longitudinal vibration piezoelectric ceramic piece is polarized along the thickness direction, and the two piezoelectric ceramic pieces are arranged in the same direction.

5. A driving method for a piezoelectric driven outer pipe climbing robot according to any one of claims 1 to 4, characterized in that: The following steps are involved: Applying an excitation voltage of the same amplitude and frequency to the piezoelectric ceramic piece to excite the vibrating body to vibrate; According to the task requirements, the phase difference of the excitation voltage between the piezoelectric ceramic sheets is adjusted so that the vibrating body drives the creeping gear to move relative to the ground; After use, turn off the excitation voltage and reset the transducer unit.

6. The driving method of the piezoelectric driven outer pipe climbing robot according to claim 5, characterized in that: When the phases of the two excitation signals differ by 180°, the front piezoelectric ceramic sheet stretches in the length direction and the rear piezoelectric ceramic sheet shortens in the length direction. When the front piezoelectric ceramic sheet shortens in the length direction, the rear piezoelectric ceramic sheet stretches in the length direction. Under the excitation of the two piezoelectric ceramic sheets, the vibrating body is promoted to complete the second-order bending vibration, and at the same time, the creeping teeth are driven to move relative to the ground, causing the transducer unit to move backward.

7. The driving method of the piezoelectric driven outer pipe climbing robot according to claim 5, characterized in that: When the phase difference is 0°, the piezoelectric ceramic sheets on the front and rear sides move in the same way, promoting the vibrator to complete the third-order bending vibration, while driving the creeping teeth to move relative to the ground, causing the transducer unit to move forward.

Images