A micro-crawler actuator and driving method based on stacked piezoelectric ceramics

Abstract

This invention discloses a miniature pipe-climbing actuator and its driving method based on stacked piezoelectric ceramics, relating to the field of pipe crawling technology. The actuator includes a driving mechanism, a walking mechanism, a supporting mechanism, and a force-applying mechanism. The driving mechanism provides driving force to the walking mechanism and includes a first stacked piezoelectric ceramic and a second stacked piezoelectric ceramic. Thin sheets with convex structures are disposed on the first and second stacked piezoelectric ceramics. These sheets are used to change the vibration direction of the piezoelectric ceramics and amplify their actuation displacement. The force-applying mechanism, combined with the walking mechanism, enables the actuator to climb and move on the pipe. The driving mechanism, walking mechanism, and force-applying mechanism are all mounted on the supporting mechanism. This actuator can achieve flexible climbing on small-diameter, multi-material pipe surfaces, while also achieving high speed, high precision, and good load capacity.

Description

Technical Field

[0001] This invention relates to the field of pipe crawling technology, and in particular to a micro pipe crawling actuator and driving method based on stacked piezoelectric ceramics. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] With the continuous development of urban infrastructure, energy transmission, and precision manufacturing, a large number of small-diameter pipeline systems are widely used in industries such as water supply, gas, communications, power, and chemicals. These pipelines are usually laid in areas with limited space or complex environments, such as underground pipe networks, building mezzanines, or inside enclosed equipment, which brings great difficulties to routine inspection and maintenance operations. Once the pipeline structure is damaged or aged, if it is not detected and dealt with in time, it can easily lead to leaks, interruptions, or even major safety accidents, causing huge economic losses and safety hazards.

[0004] Therefore, developing a miniature actuator capable of autonomous climbing, flexible movement, and online inspection has become a significant technical challenge to address the needs of pipeline inspection in situations involving small diameters, long distances, and environmental constraints.

[0005] Some traditional climbing mechanisms based on wheeled, suction-type, or mechanical gripping structures use a drive mechanism composed of a motor, gear reduction mechanism, and worm gear reducer connected together. The motor outputs power through the gear reduction mechanism, and the worm gear reducer outputs power to the rollers, driving the rollers to rotate. There is also a suction cup-type wall-climbing robot that utilizes the coordinated work of an air pump and an electronic control device to achieve walking operations on smooth surfaces. Other climbing robots can effectively adjust the gripping posture of their robotic arms to adapt to changes in the angle of the angle steel in power transmission towers. While these robots improve inspection efficiency to some extent, their large size, complex structure, or strong dependence on materials and surface conditions make it difficult to meet the requirements for efficient and stable operation in small-sized pipe environments. In particular, existing pipe-climbing robots have significant shortcomings in miniaturization and high-resolution motion control. Miniaturization inevitably leads to space constraints, while traditional motor drive units generally suffer from large size, slow response, and high energy consumption, severely limiting the overall performance of the system. Furthermore, when operating in complex environments, the mechanism needs extremely high mobility and path adaptability, which places higher demands on the drive mechanism.

[0006] Piezoelectric actuation technology, due to its unique working mechanism—utilizing the inverse piezoelectric effect of materials to achieve high-frequency micro-displacement—naturally possesses advantages such as rapid response, high thrust density, low energy consumption, small size, and precise control, making it an important direction for overcoming the technological bottlenecks of micro-pipe crawling actuators. Existing technologies include an adaptive bidirectional micro-piezoelectric pipe crawling robot capable of adapting to pipes of different diameters, with iris-like rotary disc retainers at both ends enabling bidirectional movement. Another piezoelectric-driven micro-pipe inspection robot utilizes the synergistic cooperation of an X-type piezoelectric ceramic actuator and a slotted cymbal deformer to effectively improve the robot's movement speed within pipes. In particular, the stacked piezoelectric ceramic structure, through the series connection of multiple piezoelectric units, utilizes the combined movement of piezoelectric plates and elastic driving legs to propel the crawling robot in the direction of thrust. This significantly improves the overall displacement output and load-bearing capacity, providing a powerful driving foundation for micro-actuators. However, currently all piezoelectric-driven pipe crawling actuators rely on external power supplies and must be connected to the power system via cables. This cabled connection method severely restricts the actuator's freedom of movement and operating range in practical applications. It is prone to unstable energy transmission due to cable entanglement, dragging, or bending, and may even lead to jamming, detachment, and other malfunctions, seriously affecting the reliability, flexibility, and practicality of the micro-actuator in complex and narrow pipe environments. Therefore, there is an urgent need to develop micro-piezoelectric pipe-climbing robots capable of independent cable-free drive and energy supply to completely solve the technical bottleneck of existing piezoelectric systems being constrained by external cables.

[0007] In conclusion, for complex pipeline environments, better balancing the robot's efficient climbing performance and load-bearing capacity is of great significance for improving the intelligence level of pipeline inspection, reducing maintenance costs, and enhancing operational safety. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a micro pipe crawler actuator and driving method based on stacked piezoelectric ceramics, which can achieve flexible climbing on the surface of small-diameter, multi-material pipes, while taking into account high speed, high precision and good load capacity.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0010] The first aspect of the present invention provides a miniature pipe-climbing actuator based on stacked piezoelectric ceramics, including a driving mechanism, a walking mechanism, a supporting mechanism, and a force-applying mechanism. The driving mechanism is used to provide driving force for the walking mechanism. The driving mechanism includes a first stacked piezoelectric ceramic and a second stacked piezoelectric ceramic. The first stacked piezoelectric ceramic and the second stacked piezoelectric ceramic are provided with thin plates with convex structures. The thin plates are used to change the vibration direction of the piezoelectric ceramic and amplify the actuation displacement of the piezoelectric ceramic. The force-applying mechanism, combined with the walking mechanism, enables the actuator to climb and walk on the pipe. The driving mechanism, the walking mechanism, and the force-applying mechanism are all mounted on the supporting mechanism.

[0011] Furthermore, the thin sheet is coupled to the first stacked piezoelectric ceramic and the second stacked piezoelectric ceramic via a coupling agent.

[0012] Furthermore, the drive mechanism also includes a drive circuit and a battery. The drive circuit includes a wireless receiver module, a BOOST boost module, a gate drive module, an H-bridge drive module, and an MCU.

[0013] Furthermore, the support mechanism includes a first body and a second body. The first body and the second body are the same and are both made of aluminum alloy. The first body and the second body have multiple hollowed-out areas.

[0014] Furthermore, the force-applying mechanism includes a force-applying screw, a longitudinal helical spring, and a force-applying nut. The force-applying screw is connected to the first body and the second body respectively, and the longitudinal helical spring and the force-applying nut are mounted on the force-applying screw.

[0015] Furthermore, the walking mechanism includes a first driving foot and a second driving foot, the first driving foot being connected to a thin sheet on a first stacked piezoelectric ceramic, and the second driving foot being connected to a thin sheet on a second stacked piezoelectric ceramic.

[0016] Furthermore, the displacement generated by the stacked piezoelectric ceramics is transmitted to the connected drive foot through the amplification mechanism, thereby causing the drive foot to generate a downward force. This downward force is decomposed into a horizontal force and a vertical force. The horizontal force is used to overcome the preload of the longitudinal helical spring, while the vertical force is used to overcome gravity and cause the actuator to climb along the pipe.

[0017] Furthermore, the first and second drive feet are provided with multiple cutouts, and the ends of both the first and second drive feet are designed with arc-shaped blade structures to accommodate pipes of different diameters and shapes.

[0018] Furthermore, the lower ends of the first and second driving feet are designed with hinge structures to release excess constraints and stress, and also to amplify the displacement of the driving foot ends.

[0019] A second aspect of the present invention provides a driving method for a micro-crawler actuator based on stacked piezoelectric ceramics as described in the first aspect, comprising the following steps:

[0020] Generate driving signals according to task requirements;

[0021] When a drive signal is applied to the drive mechanism, the first stacked piezoelectric ceramic and the second stacked piezoelectric ceramic vibrate along the length direction;

[0022] The thin sheet converts vibrations along the length direction into vibrations along the thickness direction, thereby driving the movement of the walking mechanism.

[0023] The above one or more technical solutions have the following beneficial effects:

[0024] This invention discloses a miniature pipe-climbing actuator and its driving method based on stacked piezoelectric ceramics. Addressing the problems of large size, insufficient thrust, and reliance on cable power supply in existing pipe-climbing actuators, a systematic improvement design is proposed. Firstly, by employing a stacked piezoelectric ceramic driving unit with a lightweight hollowed-out aluminum alloy body and driving foot structure, the overall size and weight are effectively reduced, achieving miniaturization and high flexibility of the actuator. Simultaneously, the introduction of an adaptive clamping mechanism formed by a longitudinal helical spring in conjunction with a force-applying screw and nut, along with an end-curved blade driving foot design, enables the actuator to dynamically adjust the clamping force according to different pipe diameters and materials, achieving stable operation without the need for traditional adsorption methods. This significantly improves its adaptability and reliability in confined spaces, curved surfaces, and non-metallic pipes.

[0025] This invention employs a multi-layer series structure of stacked piezoelectric ceramic units, combined with a stainless steel sheet amplification mechanism with convex upper and lower surfaces, which greatly improves the displacement and output thrust of a single step, significantly enhancing the thrust density and movement speed of the drive system.

[0026] This invention's drive circuit design employs a high-voltage BOOST boost module and a low-frequency optimized H-bridge circuit, fully matching the high-voltage, high-charge characteristics of the stacked piezoelectric units. This effectively improves the energy utilization and response performance of the piezoelectric actuator, meeting the requirements for rapid and efficient movement. This invention integrates the battery and drive circuitry within the actuator, achieving completely cable-free autonomous drive. It eliminates the space and operational limitations imposed by traditional cable connections, enabling the actuator to operate independently and continuously over long distances, along complex curved paths, and in enclosed spaces. This greatly expands practical application scenarios and enhances the system's mobility and the reliability of task completion.

[0027] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a structural diagram of the micro-crawler actuator based on stacked piezoelectric ceramics driven in Embodiment 1 of the present invention;

[0030] Figure 2 This is a schematic diagram of the driving signals in Embodiment 1 of the present invention;

[0031] Figure 3 This is a schematic diagram of the working mechanism of the convex sheet in Embodiment 1 of the present invention;

[0032] Figure 4 This is a schematic diagram illustrating the mechanism of the concave sheet in Embodiment 1 of the present invention;

[0033] Figure 5 This is a schematic diagram of the driving circuit in Embodiment 1 of the present invention;

[0034] Figure 6 This is a flowchart illustrating the working principle of the micro-climbing actuator based on stacked piezoelectric ceramics driven in Embodiment 1 of the present invention.

[0035] Among them, 1. First stacked piezoelectric ceramic, 2. First driving foot, 3. First body, 4. Second stacked piezoelectric ceramic, 5. Second driving foot, 6. Second body, 7. Force-applying screw, 8. Longitudinal helical spring, 9. Force-applying nut, 10. Drive circuit, 11. Battery. Detailed Implementation

[0036] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, 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 pertains.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0039] Example 1:

[0040] Embodiment 1 of the present invention provides a micro-crawler actuator based on stacked piezoelectric ceramics, such as... Figure 1 As shown, it includes a drive mechanism, a traveling mechanism, a support mechanism, and a force-applying mechanism. The drive mechanism provides driving force to the traveling mechanism, and the force-applying mechanism, in conjunction with the traveling mechanism, enables the actuator to climb and travel on the pipeline. The drive mechanism, the traveling mechanism, and the force-applying mechanism are all mounted on the support mechanism.

[0041] In one specific embodiment, the support mechanism includes a first body 3 and a second body 6. The first body 3 and the second body 6 are identical and both are made of aluminum alloy. The first body 3 and the second body 6 are arranged symmetrically from left to right, and force-applying screws 7 are provided on both the front and rear sides. The first body 3 and the second body 6 have multiple hollowed-out areas to reduce weight.

[0042] The first body 3 and the second body 6 each include an upper surface, a side surface, a front surface, and a rear surface. The front surface, rear surface, and side surface are perpendicularly connected to the circuit board of the drive circuit. The front and rear surfaces are set at obtuse angles to the side surface because they need to connect to the force-applying mechanism. The upper surface is also set at an obtuse angle to the side surface because it needs to utilize the thrust generated by the piezoelectric ceramic to overcome gravity while simultaneously breaking free from the preload. Through simulation experiments and other methods, it was determined that a 70° angle between the direction of the force generated by the piezoelectric ceramic and the horizontal line is most suitable. Therefore, the angle between the upper surface and the side surface is designed based on the angle between the stacked piezoelectric ceramics and the horizontal line. Furthermore, space needs to be reserved for the force-applying mechanism to connect the two bodies, and sufficient space also needs to be reserved for pipes. Finally, a hollow design is needed to reduce weight. Therefore, the bodies are hollowed out as much as possible when conditions permit to reduce weight, while maintaining a certain degree of rigidity. Based on the above considerations, this embodiment designs a support mechanism as follows: Figure 1 As shown.

[0043] In one specific embodiment, the driving mechanism includes a first stacked piezoelectric ceramic 1 and a second stacked piezoelectric ceramic 4. The first stacked piezoelectric ceramic 1 and the second stacked piezoelectric ceramic 4 are provided with thin sheets with convex structures. The thin sheets are made of stainless steel and are used to change the vibration direction of the piezoelectric ceramic and amplify the actuation displacement of the piezoelectric ceramic.

[0044] The specific structure of the thin sheet is as follows Figure 3 and Figure 4As shown, the four sides of the thin sheet can be bonded to the stacked piezoelectric ceramic using epoxy resin, with the top and bottom surfaces also bonded. The middle portion of the thin sheet is designed to be suspended, not in direct contact with the stacked piezoelectric ceramic. When the stacked piezoelectric ceramic receives an electrical signal and stretches or shortens, it exerts a tensile force on the thin sheet, causing the middle of the sheet to exhibit concave-convex movement. This thin sheet can not only change the direction of the piezoelectric ceramic's output displacement but also amplify the output displacement.

[0045] It should be noted that, in this embodiment, in order to achieve better results, two thin sheets can be bonded to a stacked piezoelectric ceramic. The two thin sheets are arranged one above the other to achieve simultaneous upward and downward convex movements.

[0046] The displacement and thrust of the piezoelectric ceramics are amplified approximately tenfold after passing through the amplification mechanism (i.e., the thin plate). This increases the displacement and thrust per single movement at the same frequency, effectively improving thrust density and achieving high speed and high load. The thin plate is coupled to the first and second stacked piezoelectric ceramics via a coupling agent. Specifically, the surface area of ​​the thin plate is the same size as the upper surface of the machine body, and it is coupled to the four sides of the corresponding stacked piezoelectric ceramics via the coupling agent. Since the thin plate is only fixed to the four sides, it can deform upwards and downwards in response to the drive signal, thereby driving the drive legs to move. The drive legs, in conjunction with the force application mechanism, enable pipe climbing.

[0047] The drive mechanism also includes a drive circuit 10 and a battery 11. The drive circuit 10 includes a wireless receiver module, a boost module, a gate drive module, an H-bridge drive module, and an MCU. The drive circuit is in the form of a circuit board. The battery 11 is mounted on the lower surface of the circuit board, and the support mechanism is mounted on the upper surface of the circuit board. A square through hole is provided in the middle of the circuit board for the pipe to pass through, but the square through hole does not contact the pipe. Initially, the robot, along with the circuit board, is manually inserted directly through the bottom of the pipe and fitted onto the pipe.

[0048] like Figure 2 As shown, the stacked piezoelectric ceramics in this embodiment are driven by a square wave waveform.

[0049] The working principle and specific workflow of the drive circuit are as follows: Figure 5 , Figure 6As shown: After the driver circuit board is powered on, the 12V voltage of the lithium battery is stepped down to 3.3V for the MCU. Then, it waits for the Bluetooth communication module in the wireless receiver module to receive the remote control signal, parses the received signal, and outputs the corresponding control signal. The remote control signal includes motion commands such as the actuator's climbing, speed, and stepping. Based on the parsed control signal, specific motion control parameters are determined, and the drive signal is adjusted accordingly. The drive signal parameters include frequency f and voltage U. The voltage action is as follows: the MCU obtains the voltage of the target drive signal, generates a PWM control signal through a timer, and outputs it to the BOOST module. The BOOST module boosts the voltage, uses an LM5156 signal, and filters the output signal to obtain voltage U. Simultaneously, the frequency of the drive signal is adjusted: based on the content of the control signal, the MCU generates two adjustable duty cycle square waves with opposite phases and a certain dead time through a timer, and outputs them to the gate drive module, thus obtaining the H-bridge control signal. The H-bridge control signal is used to control the opening and closing of the H-bridge circuit's switching elements. Changing the frequency of the control signal changes the switching frequency of the switching elements, and the frequency of the output drive signal changes accordingly. The designed H-bridge circuit, specifically designed to drive the stacked piezoelectric ceramics, employs low-frequency signal drive, making it suitable for high-voltage, high-charge piezoelectric drive elements. Upon receiving a control signal, it outputs a drive signal to the load, i.e., the stacked piezoelectric ceramics. A gyroscope continuously monitors the actuator's acceleration and velocity, and a PID algorithm is used in real-time to optimize and adjust the drive signal, feeding it back to the stacked piezoelectric ceramics to regulate the actuator's motion.

[0050] It should be noted that when the robot needs to move backward, it is only necessary to change the drive frequency. When the force generated by the piezoelectric ceramic at the current drive frequency is insufficient to push the robot upward, the robot will move backward based on the effect of gravity.

[0051] This embodiment employs stacked piezoelectric ceramic units, with multiple layers connected in series to enhance overall output energy. Combined with an upper and lower convex stainless steel sheet amplification mechanism, it improves the thrust density and movement speed of the drive system. Furthermore, the high-voltage BOOST boost and low-frequency optimized H-bridge drive circuit further enhance the operating efficiency of the piezoelectric elements.

[0052] In one specific embodiment, the force-applying mechanism includes a force-applying screw 7, a longitudinal helical spring 8, and a force-applying nut 9. The force-applying screw 7 is connected to the first body 3 and the second body 6, respectively. The longitudinal helical spring 8 and the force-applying nut 9 are mounted on the force-applying screw 7. Specifically, in this embodiment, an extending hole is provided on the front and rear surfaces of the first and second bodies, respectively. One force-applying screw passes through the hole on the front surface of the first and second bodies, and another force-applying screw passes through the hole on the rear surface of the first and second bodies, respectively. The two force-applying screws are parallel to the circuit board of the drive circuit and perpendicular to the pipe. The two ends of the force-applying screws extending out of the holes are locked with force-applying nuts, and a longitudinal helical spring is provided between the force-applying nut at one end and the hole.

[0053] The lightweight, integrated structure and adaptive clamping mechanism design enhance both miniaturization and flexibility.

[0054] Initially, the force-applying nut is not tightened, leaving enough space for the robot to fit onto the pipe. Then, the force-applying nut is tightened, and the longitudinal helical spring is compressed against the machine body to find the appropriate preload and achieve the best climbing effect.

[0055] In one specific embodiment, the walking mechanism includes a first driving foot 2 and a second driving foot 5. The first driving foot 2 is connected to a sheet on a first stacked piezoelectric ceramic 1, and the second driving foot 5 is connected to a sheet on a second stacked piezoelectric ceramic 4.

[0056] Specifically, the lower stainless steel sheet of the first stacked piezoelectric ceramic is bonded to the center of the first drive foot, and the lower stainless steel sheet of the second stacked piezoelectric ceramic is bonded to the center of the second drive foot. The displacement generated by the stacked piezoelectric ceramics is transmitted to the connected drive foot through the amplification mechanism, thereby causing the drive foot to generate a downward force. This downward force is decomposed into a horizontal force and a vertical force. The horizontal force is used to overcome the preload of the longitudinal helical spring, allowing it to move freely; the vertical force is used to overcome gravity and cause the actuator to climb along the pipe. The first and second drive feet have multiple cutouts, and the ends of both the first and second drive feet are designed with arc-shaped blade structures to accommodate pipes of different diameters and shapes.

[0057] A curved edge structure refers to a structural component with a contact edge formed along an arc-shaped contour. Its shape is curved or arc-shaped, and compared to traditional straight or sharp-angled edges, this structure can better conform to curved surfaces such as pipes. The cutting edge (i.e., the edge portion) of this structure is usually used for contact, support, or to generate interaction forces with other mechanisms, and it has a certain degree of self-adaptive conformation ability during movement or deformation.

[0058] The lower ends of the first and second drive feet are designed with hinge structures to release excess constraints and stress, and to amplify the displacement at the ends of the drive feet, enabling better climbing motion. The first and second drive feet are identical, symmetrically arranged, each including an upper drive foot and a lower drive foot. Taking the first drive foot as an example, one end of the upper drive foot connects to the upper surface of the first body, and the other end connects to the lower drive foot. The other end of the lower drive foot is connected to the side of the first body via a fixed bracket. In this embodiment, the entire drive foot is integrally formed during manufacturing. The lower drive foot is horizontally positioned, while the upper drive foot has an inclined angle, and the hinge structure is located on the lower drive foot. This hinge structure is a "rigid-soft-rigid" design, meaning that a flexible connection area is formed within the overall rigid material through localized weakening. When the piezoelectric ceramic undergoes displacement, this displacement is transmitted along the drive foot to the hinge position. Because this is a relatively flexible connection area, it can produce a certain degree of elastic deformation under force, thereby achieving relative rotation or torsion, ultimately outputting the desired motion pattern.

[0059] Most importantly, the actuator in this embodiment, due to its excellent load-carrying capacity and high-efficiency drive circuit, can be used not only with an external power supply but also without a cable (with its own power supply), including the drive circuit 10 and the battery 11.

[0060] like Figure 3 and Figure 4 As shown, the actuation mechanism of stacked piezoelectric ceramics is as follows: a driving signal is generated according to the task requirements;

[0061] When a drive signal is applied to the drive mechanism, the first and second stacked piezoelectric ceramics vibrate along their length. The upper and lower stainless steel sheets convert this length-direction vibration into thickness-direction vibration, thereby driving the walking mechanism's foot. Specifically, when the drive signal is negative, the piezoelectric ceramics contract inwards, acting on the stainless steel sheets to make them bulge upwards, amplifying the output and changing its direction. The walking foot experiences a downward pushing force from the stacked piezoelectric ceramics, manifesting as the walking foot "pushing off." When the drive signal is positive, the piezoelectric ceramics expand outwards, acting on the stainless steel sheets to make them concave downwards. The walking foot experiences an upward pulling force from the stacked piezoelectric ceramics, manifesting as the walking foot "retracting." Due to the sufficiently high drive frequency, the macroscopic manifestation is climbing upwards along a pipe.

[0062] This embodiment employs a combination of stacked piezoelectric ceramic drive, a compact aluminum alloy body, and a lightweight design with hollowed-out drive legs, significantly reducing overall size and weight. The introduction of an arc-shaped blade structure and longitudinal helical springs, along with force-applying screws and nuts, forms an adaptive clamping mechanism that dynamically adapts to different pipe diameters and materials, eliminating reliance on adsorption methods and making the system simpler and more reliable. This embodiment integrates a battery and a high-efficiency drive circuit, achieving cable-free autonomous drive, overcoming the spatial constraints of cabled control, and broadening its practical application areas.

[0063] The miniature pipe-climbing actuator designed in this embodiment, based on stacked piezoelectric ceramics, maintains essentially constant motion performance under different pipe diameters and shapes. With a 50V excitation signal, it achieves a maximum climbing angle of 90°, a movement speed of 103 mm / s, and a high load-to-weight ratio of 5.9 when tethered; and a maximum climbing angle of 45°, a maximum movement speed of 40 mm / s, and a high load-to-weight ratio of 0.9 when untethered. This represents a performance breakthrough for miniature pipe-climbing actuators and reveals their application prospects in various industrial environments.

[0064] Example 2:

[0065] Embodiment 2 of the present invention provides a driving method for a micro-crawler actuator based on stacked piezoelectric ceramics as described in Embodiment 1, comprising the following steps:

[0066] Step 1: Generate drive signals according to task requirements.

[0067] Step 2: Apply a driving signal to the driving mechanism, and the first stacked piezoelectric ceramic and the second stacked piezoelectric ceramic vibrate along the length direction.

[0068] Step 3: The thin sheet converts the vibration in the length direction into vibration in the thickness direction, thereby driving the walking mechanism to move.

[0069] The steps involved in the above embodiment two correspond to those in embodiment one. For specific implementation details, please refer to the relevant description section of embodiment one.

[0070] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A micro-climbing actuator based on stacked piezoelectric ceramics, characterized in that, It includes a drive mechanism, a walking mechanism, a support mechanism, and a force-applying mechanism. The drive mechanism provides driving force to the walking mechanism and includes a first stack of piezoelectric ceramics and a second stack of piezoelectric ceramics. The first stack of piezoelectric ceramics and the second stack of piezoelectric ceramics are provided with thin plates with convex structures. The thin plates are used to change the vibration direction of the piezoelectric ceramics and amplify the actuation displacement of the piezoelectric ceramics. The middle part of the thin plate is designed to be suspended and does not directly contact the stack of piezoelectric ceramics. The force-applying mechanism, together with the walking mechanism, enables the actuator to climb and walk on the pipeline. The drive mechanism, the walking mechanism, and the force-applying mechanism are all mounted on the support mechanism. The support mechanism includes a first body and a second body. The first body and the second body are identical and both are made of aluminum alloy. The first body and the second body have multiple cutouts. The first body and the second body are symmetrically arranged from left to right. Force-applying screws are provided on the front and rear sides. The first body and the second body each include an upper surface, a side surface, a front surface, and a rear surface. The front surface, the rear surface, and the side surface are perpendicularly connected to the circuit board of the drive circuit. The front surface and the rear surface are set at an obtuse angle to the side surface. The front surface and the rear surface of the first body and the second body each have an extending hole. The force-applying screws pass through the holes on the front surfaces of the first body and the second body respectively. Another force-applying screw passes through the holes on the rear surfaces of the first body and the second body respectively. The two ends of the force-applying screws extending out of the holes are locked with force-applying nuts. A longitudinal helical spring is provided between the force-applying nut at one end and the hole. The first stacked piezoelectric ceramic is located on the underside of the upper surface of the first body, and the second stacked piezoelectric ceramic is located on the underside of the upper surface of the second body. The force-applying mechanism includes a force-applying screw, a longitudinal helical spring, and a force-applying nut. The force-applying screw is connected to the first body and the second body respectively, and the longitudinal helical spring and the force-applying nut are mounted on the force-applying screw. The walking mechanism includes a first driving foot and a second driving foot. The first driving foot and the second driving foot are the same and are symmetrically arranged on the left and right. Both include an upper driving foot and a lower driving foot. Taking the first driving foot as an example, one end of the upper driving foot of the first driving foot is connected to a thin sheet on the first stacked piezoelectric ceramic, and the other end is connected to the lower driving foot. The other end of the lower driving foot is connected to the side of the first body through a fixed bracket. The second driving foot is connected to a thin sheet on the second stacked piezoelectric ceramic.

2. The micro-climbing actuator based on stacked piezoelectric ceramics as described in claim 1, characterized in that, The thin sheet is coupled to the first stacked piezoelectric ceramic and the second stacked piezoelectric ceramic via a coupling agent.

3. The micro-climbing actuator based on stacked piezoelectric ceramics as described in claim 1, characterized in that, The drive mechanism also includes a drive circuit and a battery. The drive circuit includes a wireless receiver module, a BOOST boost module, a gate drive module, an H-bridge drive module, and an MCU.

4. The micro-climbing actuator based on stacked piezoelectric ceramics as described in claim 1, characterized in that, The displacement generated by the stacked piezoelectric ceramics is transmitted through the thin sheet to the connected drive foot, thereby causing the drive foot to generate a downward force. The downward force is decomposed into a horizontal force and a vertical force. The horizontal force is used to overcome the preload of the longitudinal helical spring; the vertical force is used to overcome gravity and cause the actuator to climb along the pipe.

5. The micro-climbing actuator based on stacked piezoelectric ceramics as described in claim 4, characterized in that, The first and second drive feet have multiple cutouts, and the ends of both the first and second drive feet are designed with arc-shaped blade structures to accommodate pipes of different diameters and shapes.

6. The micro-climbing actuator based on stacked piezoelectric ceramics as described in claim 5, characterized in that, The lower ends of the first and second driving feet are designed with hinge structures to release excess constraints and stress, and also to amplify the displacement of the driving foot ends.

7. A driving method for a micro-crawler actuator based on stacked piezoelectric ceramics as described in any one of claims 1-6, characterized in that, Includes the following steps: Generate driving signals according to task requirements; When a drive signal is applied to the drive mechanism, the first stacked piezoelectric ceramic and the second stacked piezoelectric ceramic vibrate along the length direction; The thin sheet converts vibrations along the length direction into vibrations along the thickness direction, thereby driving the movement of the walking mechanism.

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