Dual-mode inertially driven micro piezoelectric robot and its excitation method

Abstract

A kind of dual-mode inertial drive micro piezoelectric robot and its excitation method belong to the technical field of micro robot. Including upper mass, flexible hinge, drive unit, support foot;By applying excitation signal to drive unit to make it produce bending deformation, push the upper mass of robot to rotate around flexible hinge, generate inertial force in oblique front direction through the process of lifting and falling of upper mass to realize the forward movement of robot;According to the waveform and frequency of excitation signal, the robot can realize two kinds of inertial motion modes of jumping and resonance. Adjust the configuration mode of mass and drive unit, the robot can form two parallel inertial forces in the forward direction, and also can produce corresponding inertial force in the backward direction, realize the steering motion and forward and backward linear motion on the plane. It has the characteristics of simple structure, light weight, high resolution and fast speed. It has wide application prospect in the field of micro-nano operation, biological medicine and other fields in narrow space.

Description

Technical Field

[0001] This invention belongs to the field of micro-robot technology, specifically relating to a dual-mode inertial driven micro-piezoelectric robot and its excitation method. Background Technology

[0002] Micro-mobile robots have seen widespread development due to their advantages such as small size, flexible movement, low cost, strong environmental adaptability, and good stealth capabilities, finding broad applications in fields such as biomedical engineering, micromanipulation, and search and rescue. Traditional micro-robots typically employ electromagnetic actuators, which offer advantages such as simple control and high movement speed. However, the presence of bearings and transmission mechanisms limits the further miniaturization of electromagnetic actuators. Therefore, to avoid these problems, researchers have developed various smart materials, such as shape memory alloys, magnetostrictive materials, dielectric elastomers, and piezoelectric ceramics. Among these, micro-robots driven by piezoelectric ceramics have advantages such as simple structure, high resolution, fast response, and good electromagnetic compatibility, making them popular among researchers and institutions.

[0003] Miniature piezoelectric robots can generally be classified into resonant, direct-drive, walking, inchworm, and inertial types based on their working principles. Resonant miniature mobile robots generate elliptical or oblique motion trajectories at the driving feet by exciting the resonance of piezoelectric elements; larger resonant amplitudes are beneficial for achieving higher speeds, but can also lead to irregular motion and poor controllability. Direct-drive miniature mobile robots directly utilize the deformation of piezoelectric elements for propulsion, offering advantages such as no wear and high resolution, but their motion range is limited to a few hundred micrometers. Walking miniature mobile robots achieve stepping motion through the coordinated excitation of multiple piezoelectric elements, with static friction always present between the driving feet and the ground. Inchworm-type miniature mobile robots have advantages such as low wear, high output force, and high motion stability, but their structure and control scheme are complex. For inertial miniature mobile robots, piezoelectric elements generate inertial force under the excitation of sawtooth wave signals to overcome friction and achieve stepping motion. Inertial miniature mobile robots have simple structures and simple driving signals, but their speed is typically limited to a few millimeters per second.

[0004] Inertial micro-mobile robots are compact in structure and have simple actuation signals, which is conducive to miniaturization and has attracted much research attention; however, their single-step displacement and motion speed are limited. Therefore, while ensuring robot miniaturization, this invention designs a novel inertial-driven robot and proposes two unconventional inertial motion modes to achieve high resolution, large step size, and high speed. It has broad application prospects in fields such as biomedicine, aerospace, materials science, chemistry, and microelectronic devices. Summary of the Invention

[0005] To address the limitations of single-step displacement and motion speed in traditional inertial-driven robots, this invention provides a dual-mode inertial-driven micro-piezoelectric robot and its excitation method.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention proposes a dual-mode inertial-driven micro piezoelectric robot, which includes an upper mass block, flexible hinges, a drive unit, and supporting legs. The bottom of the upper mass block is in contact with the top of the drive unit and is connected by a flexible hinge. The flexible hinge can be directly fixed to the upper mass block and the drive unit. The connection methods include welding, gluing, or an integrated structure. The bottom of the drive unit is connected to the support foot, and the support foot is in contact with the working plane; The robot is divided into several parts by a flexible hinge. The top part is the upper mass block, the bottom part is the supporting legs, and the rest are drive units. The robot moves by deforming the drive unit to rotate the upper mass block around the flexible hinge, and by utilizing the inertial force generated by the upper mass block.

[0007] Furthermore, the number of the aforementioned drive units can be one or two. When there are two drive units, the robot can achieve bidirectional linear motion.

[0008] Furthermore, the number of piezoelectric composite beams in the aforementioned drive unit can be one or two. When there are two piezoelectric composite beams in the drive unit, the robot can achieve steering motion.

[0009] Furthermore, when the drive unit has two piezoelectric composite beams, the drive unit includes two identical first piezoelectric composite beams and a second piezoelectric composite beam, two identical first drive blocks and a second drive block, and an outer frame; The first piezoelectric composite beam and the second piezoelectric composite beam are respectively positioned in the middle of the outer frame; The first driving block and the second driving block are respectively located at the points of maximum deformation of the first piezoelectric composite beam and the second piezoelectric composite beam to improve the displacement output effect; The heights of the first and second drive blocks are the same as or slightly larger than those of the flexible hinge.

[0010] Furthermore, the aforementioned first piezoelectric composite beam comprises a thin-walled vibration isolation beam, a matrix, and piezoelectric ceramics; The substrate is used to mount piezoelectric ceramics and support feet; Thin-walled vibration isolation beams are used to isolate motion. The support feet are used to transmit the deformation caused by the piezoelectric ceramic and are located at the point of maximum deformation in the substrate; The polarization direction of the piezoelectric ceramic is parallel to the z-axis and is fixedly connected to the lower surface of the substrate.

[0011] This invention also proposes an excitation method for large step displacement of a dual-mode inertial-driven micro-piezoelectric robot described in any of the above-mentioned embodiments. By applying a low-symmetry sawtooth wave to the piezoelectric ceramic, the robot can generate a large step displacement along the forward direction, specifically as follows: During the time interval from t0 to t1, the upper mass block is lifted diagonally forward, and its speed increases from zero to its maximum value. The force generated during this stage points diagonally backward, and its vertical component is downward, increasing the friction between the robot and the ground. The robot will not move during this stage. At time t1, the piezoelectric composite beam begins to return to its equilibrium position. The upper mass block stops lifting under the action of the flexible hinge and its speed drops rapidly to zero, thereby generating an inertial force diagonally forward, enabling the robot to move forward.

[0012] The present invention also provides an excitation method for high-speed motion of a dual-mode inertial-driven micro piezoelectric robot as described in any of the above-mentioned claims. The robot causes the piezoelectric composite beam to resonate by applying a sinusoidal signal of a specific frequency to the piezoelectric ceramic, thereby driving the upper mass block to generate a larger inertial force and a higher deformation frequency, which in turn causes the robot to generate high-speed translational motion along the y-direction.

[0013] The present invention also provides a steering motion excitation method for a dual-mode inertial drive micro-piezoelectric robot as described in any of the above. When the robot drive unit and the upper mass block are divided into left and right parts, the robot can achieve steering motion by applying different signals to different piezoelectric ceramics on both sides.

[0014] The present invention also provides a bidirectional motion excitation method for a dual-mode inertial-driven micro-piezoelectric robot as described in any one of the above claims. When the robot is equipped with two drive units, the robot excites two different drive units respectively to achieve bidirectional motion of the robot.

[0015] The beneficial effects of this invention are: This invention provides a dual-mode inertial-driven micro-piezoelectric robot and its excitation method. The robot is designed using a combination of multiple motion modes, leveraging the advantages of each to achieve high-speed motion, large step displacement, high-resolution motion, bidirectional motion, and rotation. This robot offers advantages such as simple structure and low cost, while also possessing high speed, high resolution, and large step displacement, meeting the requirements of micro-nano manipulation environments. The dual-mode inertial-driven micro-piezoelectric robot proposed in this invention has broad application prospects in micro-nano manipulation, search and rescue, and biomedicine. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional structural diagram of a steerable inertial jumping piezoelectric robot according to the present invention, wherein... Figure 1 (a) is a diagram of the robot's overall structure. Figure 1 (b) is a schematic diagram of the drive unit structure; Figure 2 This is a schematic diagram of the piezoelectric composite beam structure of a steerable inertial jumping piezoelectric robot according to the present invention; Figure 3 This is a schematic diagram of the excitation scheme for the inertial jumping piezoelectric robot described in this invention, wherein... Figure 3 (a) is a waveform diagram of the large step displacement excitation scheme. Figure 3 (b) is a waveform diagram of the high-speed motion excitation scheme; Figure 4 This is a schematic diagram illustrating the working principle of an inertial jumping piezoelectric robot according to the present invention. Figure 5 This is a three-dimensional structural diagram of a bidirectional inertial jumping piezoelectric robot according to the present invention, wherein... Figure 5 (a) is a diagram of the overall structure of the robot, in which Figure 5 (b) is a schematic diagram of the drive unit structure; Figure 6 This is a three-dimensional structural diagram of a steerable bidirectional inertial jumping piezoelectric robot according to the present invention, wherein... Figure 6 (a) is a diagram of the overall structure of the robot, in which Figure 6 (b) is a schematic diagram of the drive unit structure.

[0018] In this diagram, 1 represents the upper mass block, 2 represents the flexible hinge, 2-1 represents the first hinge, 2-2 represents the second hinge, 3 represents the drive unit, 3-1 represents the first piezoelectric composite beam, 3-1-1 represents the thin-walled vibration isolation beam, 3-1-2 represents the substrate, 3-1-3 represents the piezoelectric ceramic, 3-2 represents the second piezoelectric composite beam, 3-3 represents the first drive block, 3-4 represents the second drive block, 3-5 represents the outer frame, 4 represents the support foot, 31 represents the middle drive unit, 311 represents the piezoelectric composite beam of the middle drive unit, 312 represents the support block of the middle drive unit, 313 represents the outer frame of the middle drive unit, 32 represents the lower drive unit, 321 represents the first piezoelectric composite beam of the lower drive unit, 322 represents the second piezoelectric composite beam of the lower drive unit, 323 represents the first support block of the lower drive unit, 324 represents the second support block of the lower drive unit, and 325 represents the outer frame of the lower drive unit. Detailed Implementation

[0019] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Specific implementation method one: To address the limitations of single-step displacement and movement speed in traditional inertial drive robots, this embodiment provides a dual-mode inertial drive micro-piezoelectric robot, namely an inertial jumping piezoelectric robot capable of linear or directional movement. The robot mainly consists of an upper mass block 1, a flexible hinge 2, a drive unit 3, and supporting legs 4; The bottom of the upper mass block 1 contacts the top of the drive unit 3, and the flexible hinge 2 is directly and fixedly connected to the upper mass block 1 and the drive unit 3; the connection method includes welding, gluing, or an integrated structure.

[0021] The bottom of the drive unit 3 is connected to the support foot 4, and the support foot 4 is in contact with the working plane; The robot proposed in this embodiment is divided into multiple parts by the flexible hinge 2. The uppermost part is the upper mass block 1, the lowermost part is the supporting leg 4, and the rest are robot drive units 3. The robot drives the upper mass block 1 to rotate around the flexible hinge 2 by the deformation of the drive unit 3, and at the same time uses the inertial force generated by the upper mass block 1 to realize the robot's movement.

[0022] Furthermore, in practical applications, the number of drive units 3 can be one or two. When there are two drive units 3, the robot can achieve bidirectional linear motion.

[0023] Furthermore, in practical applications, the number of piezoelectric composite beams in the drive unit 3 is one or two. When there are two piezoelectric composite beams, the robot can achieve left and right turning movements.

[0024] This embodiment proposes a dual-mode inertial-driven micro-piezoelectric robot. By applying an excitation signal to the drive unit to cause it to bend and deform, the robot's upper mass block rotates around a flexible hinge. The robot's forward motion is achieved by generating an inertial force in the oblique forward direction during the lifting and falling of the upper mass block.

[0025] Furthermore, depending on the waveform and frequency of the applied excitation signal, the robot can achieve two inertial motion modes: jumping and resonance. Simultaneously, by adjusting the configuration of the mass block and drive unit, the robot can generate two parallel inertial forces in the forward direction and a corresponding inertial force in the backward direction, thereby achieving turning motion on a plane and linear motion in both directions. It features a simple structure, lightweight design, high resolution, and high speed. It has broad application prospects in micro-nano manipulation in confined spaces and in biomedical fields. Specific Implementation Method Two: Combination Figure 1 and Figure 2 This embodiment describes an inertial jumping piezoelectric robot capable of unidirectional linear motion and rotation. like Figure 1 As shown in (a), the robot mainly includes an upper mass block 1, a flexible hinge 2, a drive unit 3, and a support foot 4; the bottom of the upper mass block contacts the top of the drive unit, and the bottom support foot contacts the working plane. The robot is divided into multiple parts by a flexible hinge 2, with the upper mass block 1 at the top, the support foot 4 at the bottom, and the rest being the robot drive unit 3.

[0027] like Figure 1 As shown in (b), the drive unit 3 includes two identical piezoelectric composite beams 3-1 and 3-2, two identical drive blocks 3-3 and 3-4, and an outer frame 3-5. The two piezoelectric composite beams 3-1 and 3-2 are fixedly connected to the drive blocks 3-3 and 3-4, and their bottoms are fixedly connected to the piezoelectric ceramic. The drive blocks 3-3 and 3-4 play the role of transmitting deformation. They are arranged at the point of maximum deformation of the piezoelectric composite beams 3-1 and 3-2, so that the robot can make the most of the deformation of the piezoelectric composite beams 3-1 and 3-2. By applying drive signals of different frequencies and waveforms to the piezoelectric composite beams 3-1 and 3-2, various motion modes can be realized.

[0028] like Figure 2As shown, the specific structure of the piezoelectric composite beam 3-1 includes a thin-walled vibration isolation beam 3-1-1 for isolating motion, a base 3-1-2 for mounting the piezoelectric ceramic 3-1-3 and supporting feet 4, and the piezoelectric ceramic 3-1-3. The supporting feet 4 are used to transmit the deformation generated by the piezoelectric ceramic 3-1-3; they are arranged at the point of maximum deformation of the base 3-1-2 to maximize the utilization of the deformation of the piezoelectric ceramic 3-1-3. The polarization direction of the piezoelectric ceramic 3-1-3 is parallel to the z-axis and is fixedly connected to the lower surface of the base 3-1-2. Differential motion, and thus rotation, can be achieved by applying different driving signals to the two piezoelectric ceramics. Specific implementation method three: Combination Figure 3 (a) and Figure 4 This embodiment describes an implementation scheme for a large step displacement driving method. By applying a low-symmetry sawtooth wave to a piezoelectric ceramic, the robot can generate a large step displacement along the forward direction.

[0030] The working process for achieving large step displacement motion is as follows: Step 1: Apply a pressure such as... to the piezoelectric ceramic. Figure 3 (a) shows a low-symmetry rapid rise signal. During the time interval from t0 to t1, the upper mass block 1 of the robot is rapidly lifted forward diagonally, and its speed increases from zero to the maximum value. The force generated in this stage points diagonally backward, and its vertical component is downward. This increases the friction between the robot and the ground, and the robot will not move during this stage.

[0031] Step 2: Apply a pressure such as... to the piezoelectric ceramic. Figure 3 (a) shows the descent signal. At time t1, the piezoelectric composite beam begins to return to the equilibrium position. The upper mass block 1 stops lifting under the action of the flexible hinge and its speed drops rapidly to zero, thereby generating an inertial force diagonally forward, realizing the robot's forward movement.

[0032] Step 3: Repeat steps 1 and 2 above. The robot can then achieve large step displacements. Its motion principle is as follows: Figure 4 As shown. Specific implementation method four: Combination Figure 3 (b) Description of this embodiment: This embodiment provides an implementation scheme for a high-speed driving method, specifically as follows: The robot applies a force such as... to the piezoelectric ceramic. Figure 3 (b) shows a sinusoidal signal of a specific frequency that causes the piezoelectric composite beam to resonate, driving the upper mass block 1 to generate a greater inertial force and a higher deformation frequency, thereby enabling the robot to generate high-speed translational motion along the y-direction. Specific implementation method five: Combination Figure 5This embodiment describes a piezoelectric robot capable of bidirectional linear motion and inertial jumping; for example... Figure 5 As shown in (a), the robot includes an upper mass block 1, flexible hinges 2, a drive unit 3, and support feet 4. The bottom support feet 4 of the robot are in contact with the working plane. The robot can be divided into three parts, upper, middle, and lower, with the double flexible hinges 2-1 and 2-2 as the dividing lines. The upper part is the mass block 1, the middle and lower parts are the drive units 3 for bidirectional linear motion, and the bottom part is the support feet. The surface of the upper mass block 1 is in contact with the top of the middle drive unit 31, and the bottom of the middle drive unit 31 is in contact with the top of the lower drive unit 32.

[0035] Each drive unit includes a piezoelectric composite beam, a support block, and an outer frame. Taking the central drive unit 31 as an example, as follows... Figure 5 As shown in (b), the central drive unit 31 includes a piezoelectric composite beam 311, a support block 312, and an outer frame 313. The two support blocks in the two drive units respectively transmit the deformation of the two piezoelectric composite beams. The two support blocks are respectively arranged at the points of maximum deformation of the two piezoelectric composite beams, maximizing the utilization of their deformation. Depending on the waveform and frequency of the applied excitation signal, the robot can achieve two inertial motion modes: jumping and resonance. Driving the drive units 31 and 32 at the middle and bottom of the robot respectively enables bidirectional linear motion along the y-axis. Specific implementation method six: Combination Figure 6 This embodiment describes an inertial jumping piezoelectric robot capable of bidirectional linear motion and steering; for example... Figure 6 As shown in (a), the robot includes an upper mass block 1, flexible hinges 2, a drive unit 3, and support feet 4. The bottom support feet 4 of the robot are in contact with the working plane. The robot can be divided into three parts, upper, middle, and lower, with the double flexible hinges 2-1 and 2-2 as the dividing lines. The upper part is the mass block, the middle and lower parts are the drive units for bidirectional linear motion, and the bottom part is the support feet. The surface of the upper mass block 1 is in contact with the top of the middle actuator 31, and the bottom of the middle actuator 31 is in contact with the top of the lower actuator 32.

[0037] Each drive unit includes two piezoelectric composite beams and two support blocks; the following explanation will be based on the lower drive unit 32 as an example. Figure 6As shown in (b), the lower drive unit 32 includes two piezoelectric composite beams 321 and 322, two support blocks 323 and 324, and an outer frame 325 of the lower drive unit. The two support blocks 323 and 324 both transmit the deformation of the two piezoelectric composite beams 321 and 322. The two support blocks 323 and 324 are respectively arranged at the points of maximum deformation of the two piezoelectric composite beams 321 and 322, maximizing the utilization of their deformation. Depending on the waveform and frequency of the applied excitation signal, the robot can achieve two inertial motion modes: jumping and resonance. Driving the drive units 31 and 32 in the middle and bottom of the robot respectively enables bidirectional linear motion along the y-axis; driving the piezoelectric composite beams 321 and 322 in the left and right parts respectively enables differential motion, thereby achieving steering motion.

[0038] In summary, this invention provides a dual-mode inertial-driven micro-piezoelectric robot and its excitation method. The robot is designed using a combination of multiple motion modes, leveraging the advantages of each to achieve high-speed motion, large step displacement, and high-resolution motion. This robot possesses advantages such as simple structure and low cost, while also exhibiting high speed, high resolution, and large step displacement, meeting the requirements of micro-nano manipulation environments. The high-resolution excitation method for an inertial jumping piezoelectric robot proposed in this invention has broad application prospects in micro-nano manipulation, search and rescue, and biomedicine.

[0039] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A dual-mode inertial-driven micro-piezoelectric robot, characterized in that, It includes an upper mass block (1), a flexible hinge (2), a drive unit (3), and a support foot (4); The bottom of the upper mass block (1) is in contact with the top of the drive unit (3) and is connected by a flexible hinge (2); The bottom of the drive unit (3) is connected to the support foot (4), and the support foot (4) is in contact with the working plane; The robot drives the upper mass block (1) to rotate around the flexible hinge (2) by the deformation of the drive unit (3), and at the same time uses the inertial force generated by the upper mass block (1) to realize the robot's movement. The drive unit (3) includes two identical first piezoelectric composite beams (3-1) and second piezoelectric composite beams (3-2), two identical first drive blocks (3-3) and second drive blocks (3-4), and an outer frame (3-5); The first piezoelectric composite beam (3-1) and the second piezoelectric composite beam (3-2) are respectively set in the middle position of the outer frame (3-5); The first driving block (3-3) and the second driving block (3-4) are respectively located at the points of maximum deformation of the first piezoelectric composite beam (3-1) and the second piezoelectric composite beam (3-2); The heights of the first drive block (3-3) and the second drive block (3-4) are the same as those of the flexible hinge (2); The first piezoelectric composite beam (3-1) includes a thin-walled vibration isolation beam (3-1-1), a matrix (3-1-2), and a piezoelectric ceramic (3-1-3). The substrate (3-1-2) is used to mount the piezoelectric ceramic (3-1-3) and the support foot (4); Thin-walled vibration isolation beams (3-1-1) are used to isolate motion; The support foot (4) is used to transmit the deformation generated by the piezoelectric ceramic (3-1-3) and is located at the point of maximum deformation of the substrate (3-1-2).

2. The dual-mode inertial-driven micro-piezoelectric robot according to claim 1, characterized in that, The number of drive units (3) is one or two. When there are two drive units, the robot achieves bidirectional linear motion.

3. A dual-mode inertial-driven micro-piezoelectric robot according to claim 2, characterized in that, When there are two piezoelectric composite beams in the drive unit (3), the robot can achieve left and right turning movements.

4. A dual-mode inertial-driven micro-piezoelectric robot according to claim 1, characterized in that, The polarization direction of the piezoelectric ceramic (3-1-3) is parallel to the z-axis and is fixedly connected to the lower surface of the substrate (3-1-2).

5. A method for exciting large step displacements in a micro-piezoelectric robot with dual-mode inertial drive as described in any one of claims 1-4, characterized in that, By applying a low-symmetry sawtooth wave to the piezoelectric ceramic, the robot generates a large step displacement along the forward direction, specifically: During the time interval from t0 to t1, the upper mass block is lifted diagonally forward, and its speed increases from zero to its maximum value. The force generated during this stage points diagonally backward, and its vertical component is downward, increasing the friction between the robot and the ground. The robot will not move during this stage. At time t1, the piezoelectric composite beam begins to return to its equilibrium position. The upper mass block stops lifting under the action of the flexible hinge and its speed drops rapidly to zero, thereby generating an inertial force diagonally forward, enabling the robot to move forward.

6. A method for exciting the high-speed motion of a miniature piezoelectric robot with dual-mode inertial drive as described in any one of claims 1-4, characterized in that, By applying a sinusoidal signal of a specific frequency to the piezoelectric ceramic, the piezoelectric composite beam resonates, driving the upper mass block to generate greater inertial force and higher deformation frequency, thereby enabling the robot to produce high-speed translational motion along the y-direction.

7. A method for stimulating the steering motion of a miniature piezoelectric robot with dual-mode inertial drive as described in any one of claims 1-4, characterized in that, When the drive unit and the upper mass block are divided into left and right parts, different signals are applied to the different piezoelectric ceramics on both sides, so that the robot can achieve steering motion through differential speed.

8. A bidirectional motion excitation method for a micro-sized piezoelectric robot with dual-mode inertial drive as described in any one of claims 1-4, characterized in that, When a robot is equipped with two drive units, the two different drive units are excited respectively to achieve bidirectional movement of the robot.

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