Smooth motion piezoelectric driving device and method based on a flexible mechanism imitating a foreleg of a mantis

Abstract

The application discloses a smooth motion piezoelectric driving device and method based on a manticore foreleg flexible mechanism. The device comprises a base, a rotating shaft rotatably installed on the base, two manticore foreleg flexible mechanisms which are rotatably symmetrically installed on the base with the center line of the rotating shaft as the center of rotation, the rotating angle is preferably 180 degrees, and one end of the manticore foreleg flexible mechanism is in pre-tight contact with the side wall of the rotating shaft and can realize self-locking, a clutch piezoelectric element arranged in one installation groove of the manticore foreleg flexible mechanism, and a driving piezoelectric element arranged in another installation groove of the manticore foreleg flexible mechanism, and the center line of the driving piezoelectric element is arranged at an angle with the center line of the clutch piezoelectric element. The driving method of the smooth motion piezoelectric driving device based on the manticore foreleg flexible mechanism can actively adjust to realize smooth motion, and has the advantages of miniaturization, high speed, high precision and the like.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric drive technology, and in particular to a smooth motion piezoelectric drive device and method based on a flexible mechanism mimicking the forelegs of a mantis. Background Technology

[0002] Piezoelectric precision actuation technology is an important aspect of the current equipment manufacturing industry, and has been widely applied in research fields such as precision positioning, optical systems, biomedical engineering, and micro / nano precision machining. Its core component, the piezoelectric element, has a tiny structural size, is unaffected by electromagnetic interference, and can output micrometer-level displacement and hundreds of Newtons of driving force under a defined voltage. To suit different working environments, researchers have developed various types of piezoelectric actuators, which can be broadly categorized based on their driving principles into direct-acting, ultrasonic, inchworm-type, and stick-slip piezoelectric actuators. Among them, the stick-slip piezoelectric actuator, driven by a sawtooth waveform driving signal, generates slow forward and rapid backward stepping motions through friction and its own inertia, offering advantages such as compact structure, simple control, and high resolution.

[0003] However, the inherent retraction motion of stick-slip piezoelectric actuators reduces motion speed and accuracy. Most existing methods cannot completely suppress this retraction motion, and the suppression performance cannot be actively adjusted during motion, making it difficult to adapt to complex real-world working conditions. Therefore, it is of great significance to propose a piezoelectric actuator that can actively adjust to achieve smooth motion and possesses advantages such as miniaturization, high speed, and high precision. Summary of the Invention

[0004] The purpose of this invention is to provide a piezoelectric drive device and method for smooth motion based on a flexible mechanism of a mantis forelegs, in order to solve the problems existing in the prior art. It can actively adjust to achieve smooth motion and has advantages such as being miniaturized, high-speed, and high-precision.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a smooth motion piezoelectric drive device based on a mantis-inspired foreleg flexible mechanism, comprising a base; a rotating shaft rotatably mounted on the base; two mantis-inspired foreleg flexible mechanisms, two of which are rotate symmetrically mounted on the base with the center line of the rotating shaft as the center of rotational symmetry, the rotation angle preferably being 180 degrees, and one end of each mantis-inspired foreleg flexible mechanism being in pre-tight contact with the side wall of the rotating shaft and capable of self-locking; a clutch piezoelectric element disposed in one mounting slot of the mantis-inspired foreleg flexible mechanism; and a drive piezoelectric element disposed in the other mounting slot of the mantis-inspired foreleg flexible mechanism, the center line of the drive piezoelectric element being at an angle to the center line of the clutch piezoelectric element.

[0007] Optionally, the mantis-like foreleg flexible mechanism includes a fixed end; the fixed end is fixedly mounted on the base, and a leg segment is connected to the inner side of one end of the fixed end via a flexible connecting part. A tibia is connected to the end of the leg segment via a flexible connecting part, and an arc-shaped driving foot is integrally formed at the end of the tibia. The arc-shaped driving foot is in pre-tight contact with the side wall of the rotating shaft. A mounting groove is formed between the end of the fixed end away from the flexible connecting part and the leg segment for mounting the clutch piezoelectric element. A mounting groove is also formed between the inner side of the tibia and the leg segment for mounting the drive piezoelectric element. The rotating shaft is pre-tightened to the arc-shaped driving foot at the end of the tibia and achieves self-locking. When the drive piezoelectric element slowly extends, the rotating shaft experiences friction from the arc-shaped driving foot, resulting in slow forward movement. The arc-shaped driving foot slowly deforms and accumulates elastic potential energy during the driving process. When the piezoelectric element shortens rapidly, the tibia's arc-shaped drive foot quickly retracts and recovers its deformation. Simultaneously, the arc-shaped drive foot releases elastic potential energy onto the shaft. When the initial preload between the arc-shaped drive foot and the shaft is large, resulting in low elastic potential energy, it is insufficient to offset the work done by the retraction friction, and the shaft still exhibits retraction motion, but the degree of retraction is suppressed. When the initial preload between the arc-shaped drive foot and the shaft is appropriate, resulting in suitable elastic potential energy, it precisely offsets the work done by the retraction friction, allowing the shaft to continue rotating forward smoothly. When the initial preload between the arc-shaped drive foot and the shaft is small, resulting in large elastic potential energy, the work done by the retraction friction is offset, and a forward motion friction force is generated, causing the shaft to exhibit a sudden forward motion. By adjusting the clutch piezoelectric element and applying a specific voltage, a suitable initial preload is achieved between the arc-shaped drive foot and the shaft, thus realizing smooth motion. Periodic motion accumulates the forward rotation angle to generate macroscopic continuous rotational motion.

[0008] Optionally, the fixed end away from the flexible connection part is provided with a first threaded hole communicating with the corresponding mounting groove, and the screw in the first threaded hole can pre-tighten the clutch piezoelectric element; the leg section away from the tibia section is provided with a second threaded hole communicating with the corresponding mounting groove, and the screw in the second threaded hole can pre-tighten the drive piezoelectric element.

[0009] Optionally, the flexible connection includes a first flexible hinge and a second flexible hinge; the inner side of one end of the fixed end is connected to the leg joint through the first flexible hinge, and the end of the leg joint is connected to the tibia through the second flexible hinge.

[0010] During operation, when a specific amplitude voltage is applied to the clutch piezoelectric element of this invention, the clutch piezoelectric element elongates and pushes the leg joint to rotate outward around the first flexible hinge by a certain angle. This causes the tibia, connected to the end of the leg joint, to displace radially outward along the axial direction. The arc-shaped drive foot at the end of the tibia partially recovers its deformation, thereby changing the contact state between the arc-shaped drive foot and the rotating shaft. By changing the amplitude of the voltage applied to the clutch piezoelectric element, the initial preload between the arc-shaped drive foot and the rotating shaft can be actively adjusted.

[0011] In this invention, the piezoelectric element is driven by a continuous sawtooth wave electrical signal during operation to generate periodic slow elongation and rapid shortening motions. This causes the tibia to rotate around a second flexible hinge, and the arc-shaped driving foot at the end of the tibia drives the rotating shaft to produce parasitic motion deformation, outputting stick-slip stepping motion. During the driving of the rotating shaft, the driving foot can slowly deform and accumulate elastic potential energy during the slow rise phase of the sawtooth wave electrical signal, and recover its deformation and release elastic potential energy during the rapid fall phase of the sawtooth wave electrical signal. When the voltage applied by the piezoelectric element is small, the initial preload between the arc-shaped driving foot and the rotating shaft is large, and the initial deformation of the arc-shaped driving foot is large, making it difficult to continue deforming during the driving process, resulting in less elastic potential energy. When the voltage applied by the piezoelectric element is large, the initial preload between the arc-shaped driving foot and the rotating shaft is small, and the initial deformation of the arc-shaped driving foot is small, making it easier to continue deforming during the driving process, resulting in more elastic potential energy.

[0012] Optionally, a first positioning part is fixedly provided on the inner side of the leg joint near the fixed end, and the first positioning part can abut against the end of the clutch piezoelectric element away from the first threaded hole.

[0013] Optionally, a second positioning part is fixedly provided on the inner side of the tibia near the femur, and the second positioning part can abut against the end of the driving piezoelectric element away from the second threaded hole.

[0014] Optionally, the fixing end is fixedly installed on the base by screws; the outer side of the fixing end is a smooth arc-shaped structure, and the center of the virtual circle containing the arc-shaped structure on the outer side of the fixing end coincides with the center of the base, and the radius of the virtual circle containing the arc-shaped structure on the outer side of the fixing end is the same as the outer diameter of the base.

[0015] This invention also provides a piezoelectric driving method for smooth motion based on a flexible mechanism mimicking the forelegs of a mantis, comprising the following steps:

[0016] Step 1: In the initial state, the arc-shaped drive foot of the mantis-like foreleg flexible mechanism is pre-tightened and self-locked with the rotating shaft, and the arc-shaped drive foot deforms under the action of the pre-tightening force N0.

[0017] Step 2: Apply a set amplitude voltage V1 to the clutch piezoelectric element. The clutch piezoelectric element extends and pushes the leg joint to rotate outward by an angle α around the first flexible hinge. This causes the tibia connected to the end of the leg joint to move outward along the axial direction. The arc-shaped drive foot at the end of the tibia returns to its original deformation, thereby changing the contact preload N0' between the arc-shaped drive foot and the rotating shaft. By changing the amplitude of the voltage V1 applied to the clutch piezoelectric element, the contact state between the arc-shaped drive foot and the rotating shaft can be actively controlled.

[0018] Step 3: Apply a continuous sawtooth wave signal V2 to the driving piezoelectric element. During the rising edge of the sawtooth wave, the driving piezoelectric element extends and pushes the tibia to rotate around the second flexible hinge by an angle β. The arc-shaped driving foot drives the rotating shaft to rotate in the positive direction by an angle φ, and generates deformation to accumulate elastic potential energy.

[0019] Step 4: During the falling edge of the sawtooth wave, the tibia and the arc-shaped drive foot retract and recover their deformation. Simultaneously, the arc-shaped drive foot releases elastic potential energy onto the shaft, thus suppressing retraction under the influence of the shaft's own inertia and the elastic potential energy of the arc-shaped drive foot. Adjusting the voltage V1 applied to the clutch piezoelectric element changes the initial preload N0', thereby altering the amount of elastic potential energy accumulated by the arc-shaped drive foot during the driving process, completely suppressing the shaft's retraction and achieving smooth motion. Periodic motion accumulates the positive rotation angle to generate macroscopic continuous rotational motion. The rotational speed of the shaft is adjusted by regulating the amplitude and frequency of the voltage signal from the drive piezoelectric element.

[0020] The present invention achieves the following technical effects compared to the prior art:

[0021] This invention utilizes a rotationally symmetric, mantis-inspired foreleg flexible mechanism to drive a rotating shaft. The joint structure of this mechanism allows for active adjustment of the contact state between the arc-shaped driving leg and the shaft. The elastic potential energy accumulated during the deformation of the arc-shaped driving leg suppresses backlash, achieving smooth motion of the piezoelectric drive device. This invention can generate high-resolution, high-speed, and backlash-free continuous rotational motion, and boasts advantages such as compact structure, lightweight, simple control, ease of processing and assembly, high positioning accuracy, and high rotational speed. It has a wide range of applications and shows promising prospects in precision rotary positioning, optical precision instruments, and semiconductor processing. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the mantis-inspired foreleg flexible mechanism of the present invention;

[0025] Figure 3 This is a schematic diagram illustrating the principle of the arc-shaped drive foot suppressing retraction and achieving smooth motion according to the present invention.

[0026] Figure 4 This is a schematic diagram illustrating the motion process and principle of the present invention;

[0027] Figure 5 This is a block diagram of the control system of the present invention;

[0028] Figure 6 This is a schematic diagram illustrating the principle of smooth motion adjustment in this invention.

[0029] In the figure: 1. Base; 2. Mantis-like foreleg flexible mechanism; 3. Clutch piezoelectric element; 4. Drive piezoelectric element; 5. Rotating shaft; 2-1. Fixed end; 2-2. First flexible hinge; 2-3. Leg joint; 2-4. Second flexible hinge; 2-5. Tibia; 2-5-1. Arc-shaped drive foot. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The purpose of this invention is to provide a piezoelectric drive device and method for smooth motion based on a flexible mechanism of a mantis forelegs, in order to solve the problems existing in the prior art. It can actively adjust to achieve smooth motion and has advantages such as being miniaturized, high-speed, and high-precision.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Inspired by the joint structure and arc-shaped apical hook of the praying mantis's forelegs, the inventors utilized a rotationally symmetrical, mantis-inspired flexible foreleg mechanism to drive the rotating shaft. Furthermore, the joint structure of this mantis-inspired flexible foreleg mechanism allows for active adjustment of the contact state between the arc-shaped driving leg and the rotating shaft. The elastic potential energy accumulated during the deformation process of the arc-shaped driving leg suppresses retraction, achieving smooth movement of the piezoelectric drive device. For details, refer to [reference needed]. Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, the piezoelectric drive device for smooth motion based on a mantis-inspired foreleg flexible mechanism designed in this invention includes a base 1, a mantis-inspired foreleg flexible mechanism 2, a clutch piezoelectric element 3, a drive piezoelectric element 4, and a rotating shaft 5. The mantis-inspired foreleg flexible mechanism 2 has two mounting slots for mounting the clutch piezoelectric element 3 and the drive piezoelectric element 4, respectively. The two mantis-inspired foreleg flexible mechanisms 2 are rotate symmetrically mounted on the base 1, with their ends pre-tightly contacting the rotating shaft 5 for self-locking. The rotating shaft 5 is mounted in the base 1 and located at the center of the two rotationally symmetrical mantis-inspired foreleg flexible mechanisms 2.

[0034] The mantis-inspired foreleg flexible mechanism 2 includes a fixed end 2-1, a first flexible hinge 2-2, a leg segment 2-3, a second flexible hinge 2-4, and a tibia 2-5. The fixed end 2-1 is mounted to the base 1 with screws. The leg segment 2-3 is connected to the fixed end 2-1 via the first flexible hinge 2-2. The tibia 2-5 is connected to the end of the leg segment 2-3 via the second flexible hinge 2-4. The end of the tibia 2-5 forms an arc-shaped driving foot 2-5-1, which is pre-tightened to the rotating shaft 5 and undergoes slight deformation. A mounting groove is provided between the fixed end 2-1 and the leg segment 2-3 for mounting a clutch piezoelectric element 3, and a mounting groove is provided between the leg segment 2-3 and the tibia 2-5 for mounting a drive piezoelectric element 4. Threaded holes are provided at the bottom of the mounting grooves of the fixed end 2-1 and the leg segment 2-3, which, in conjunction with screws, allow for pre-tightening of the clutch piezoelectric element 3 and the drive piezoelectric element 4.

[0035] like Figure 5 As shown, during operation, the control system applies a specific amplitude voltage to the clutch piezoelectric element 3. The clutch piezoelectric element 3 extends and pushes the first flexible hinge 2-2 of the leg segment 2-3 to rotate outward by a certain angle. This causes the tibia 2-5, connected to the end of the leg segment 2-3, to displace radially outward. The arc-shaped drive foot 2-5-1 at the end of the tibia 2-5 recovers some of its deformation, thereby changing the contact state between the arc-shaped drive foot 2-5-1 and the rotating shaft 5. By changing the amplitude of the voltage applied to the clutch piezoelectric element 3, the initial preload between the arc-shaped drive foot 2-5-1 and the rotating shaft 5 can be actively adjusted.

[0036] During operation, the piezoelectric element 4 is excited by a continuous sawtooth wave electrical signal to generate periodic slow elongation and rapid shortening motions. This causes the tibia 2-5 to rotate around the second flexible hinge 2-4. The arc-shaped driving foot 2-5-1 at the end of the tibia 2-5 drives the rotating shaft 5 to undergo parasitic motion deformation and output stick-slipping stepping motion. During the process of driving the rotating shaft 5, the driving foot 2-5-1 can slowly deform and accumulate elastic potential energy during the slow rising phase of the sawtooth wave electrical signal, and restore deformation and release elastic potential energy during the rapid falling phase of the sawtooth wave electrical signal. When the voltage applied by the clutch piezoelectric element 3 is small, the initial preload between the arc-shaped drive foot 2-5-1 and the rotating shaft 5 is large, the initial deformation of the arc-shaped drive foot 2-5-1 is large, and it is difficult to continue to deform during the driving process, resulting in a small elastic potential energy. When the voltage applied by the clutch piezoelectric element 3 is large, the initial preload between the arc-shaped drive foot 2-5-1 and the rotating shaft 5 is small, the initial deformation of the arc-shaped drive foot 2-5-1 is small, and it is easy to continue to deform during the driving process, resulting in a large elastic potential energy.

[0037] The rotating shaft 5 is rotatably mounted on the base 1 and located at the center of the two rotationally symmetrical mantis-like foreleg flexible mechanisms 2. It is pre-tightened and self-locked with the arc-shaped drive foot 2-5-1 at the end of the tibia 2-5. When the piezoelectric element 4 is slowly extended, the rotating shaft 5 is subjected to the frictional force of the arc-shaped drive foot 2-5-1, resulting in slow forward motion. The arc-shaped drive foot 2-5-1 slowly deforms and accumulates elastic potential energy during the driving process. When the piezoelectric element 4 shortens rapidly, the tibia 2-5 and the arc-shaped drive foot 2-5-1 quickly retract and recover their deformation. Simultaneously, the arc-shaped drive foot 2-5-1 releases elastic potential energy onto the rotating shaft 5. When the initial preload between the arc-shaped drive foot 2-5-1 and the rotating shaft 5 is large, resulting in a small elastic potential energy, it is insufficient to offset the work done by the retraction friction, and the rotating shaft 5 still exhibits retraction motion, but the degree of retraction is suppressed. When the initial preload between the arc-shaped drive foot 2-5-1 and the rotating shaft 5 is appropriate, resulting in suitable elastic potential energy, it precisely offsets the work done by the retraction friction, allowing the rotating shaft 5 to continue rotating forward smoothly. When the initial preload between the arc-shaped drive foot 2-5-1 and the rotating shaft 5 is small, resulting in a large elastic potential energy, the work done by the retraction friction is offset, and a forward motion friction force is generated, causing the rotating shaft 5 to exhibit a sudden forward motion. By adjusting the clutch piezoelectric element 3 to apply a specific voltage, a suitable initial preload is achieved between the arc-shaped drive foot 2-5-1 and the rotating shaft 5, thereby realizing smooth motion. The positive rotation angle is accumulated through periodic motion to generate macroscopic continuous rotational motion.

[0038] refer to Figure 4 , Figure 5 and Figure 6As shown, this invention is based on a piezoelectric drive method for smooth motion using a mantis-inspired foreleg flexible mechanism. It utilizes a rotationally symmetrical mantis-inspired foreleg flexible mechanism 2 to drive the rotating shaft 5. By applying different voltage amplitudes to the clutch piezoelectric element 3, the contact state between the arc-shaped driving leg 2-5-1 and the rotating shaft 5 is actively controlled. Furthermore, the elastic potential energy accumulated by the arc-shaped driving leg 2-5-1 during the driving deformation process is used to suppress retraction, achieving smooth motion of the piezoelectric drive device. Specifically, the method includes the following steps:

[0039] Step 1: In the initial state, the arc-shaped drive foot 2-5-1 of the mantis-like foreleg flexible mechanism 2 is pre-tightened with the rotating shaft 5 and achieves a self-locking function. The arc-shaped drive foot 2-5-1 undergoes partial deformation under the action of the pre-tightening force N0.

[0040] Step 2: Apply a specific amplitude voltage V1 to the clutch piezoelectric element 3. The clutch piezoelectric element 3 extends and pushes the first flexible hinge 2-2 of the leg joint 2-3 to rotate outward by a certain angle α. This causes the tibia 2-5 connected to the end of the leg joint 2-3 to displace radially outward along the axis. The arc-shaped drive foot 2-5-1 at the end of the tibia 2-5 recovers part of its deformation, thereby changing the contact preload N0' between the arc-shaped drive foot 2-5-1 and the rotating shaft 5. By changing the amplitude of the voltage V1 applied to the clutch piezoelectric element 3, the contact state between the arc-shaped drive foot 2-5-1 and the rotating shaft 5 can be actively controlled.

[0041] Step 3: Apply a continuous sawtooth wave signal V2 to the driving piezoelectric element 4. During the slow rising edge of the sawtooth wave, the driving piezoelectric element 4 slowly extends and pushes the tibia 2-5 to rotate around the second flexible hinge 2-4 by an angle β. The arc-shaped driving foot 2-5-1 drives the rotating shaft 5 to rotate in the positive direction by an angle φ, and generates deformation to accumulate elastic potential energy.

[0042] Step 4: During the rapid falling edge phase of the sawtooth wave, the tibia 2-5 and the arc-shaped drive foot 2-5-1 rapidly retract and recover their deformation. Simultaneously, the arc-shaped drive foot 2-5-1 releases elastic potential energy onto the rotating shaft 5, thereby suppressing the retraction of the rotating shaft 5 under the action of its own inertia and the elastic potential energy of the arc-shaped drive foot 2-5-1. Adjusting the voltage V1 applied to the clutch piezoelectric element 3 changes the initial preload N0', thereby changing the magnitude of the elastic potential energy accumulated by the arc-shaped drive foot 2-5-1 during the driving process, allowing the rotating shaft 5 to completely suppress retraction and achieve smooth motion. Periodic motion accumulates the positive rotation angle to generate macroscopic continuous rotational motion. The rotational speed of the rotating shaft 5 is adjusted by regulating the amplitude and frequency of the voltage signal from the drive piezoelectric element 4.

[0043] In the description of this invention, it should be noted that the terms "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A piezoelectric drive device for smooth motion based on a mantis-inspired foreleg flexible mechanism, characterized in that: Including the base; Rotate the shaft mounted on the base; The mantis-like foreleg flexible mechanism consists of two such mechanisms, which are rotate symmetrically mounted on the base with the center line of the rotating shaft as the center of rotational symmetry. One end of each mantis-like foreleg flexible mechanism is pre-tightly contacted with the side wall of the rotating shaft and can achieve self-locking. A clutch piezoelectric element is disposed in a mounting slot of the mantis-like foreleg flexible mechanism; A driving piezoelectric element is disposed in another mounting slot of the mantis-like foreleg flexible mechanism, and the center line of the driving piezoelectric element is set at an angle to the center line of the clutch piezoelectric element; The mantis-like foreleg flexible mechanism includes a fixed end; the fixed end is fixedly mounted on the base, and a leg segment is connected to the inner side of one end of the fixed end via a flexible connecting part. A tibia is connected to the end of the leg segment via the flexible connecting part, and an arc-shaped driving foot is integrally formed at the end of the tibia. The arc-shaped driving foot is in pre-tight contact with the side wall of the rotating shaft. A mounting groove is formed between the end of the fixed end away from the flexible connecting part and the leg segment for mounting the clutch piezoelectric element. A mounting groove is also formed between the inner side of the tibia and the leg segment for mounting the drive piezoelectric element. The flexible connecting part includes a first flexible hinge and a second flexible hinge. The inner side of one end of the fixed end is connected to the leg segment via the first flexible hinge, and the end of the leg segment is connected to the tibia via the second flexible hinge.

2. The piezoelectric drive device for smooth motion based on the flexible mechanism of a mantis forelegs according to claim 1, characterized in that: The fixed end away from the flexible connection part is provided with a first threaded hole communicating with the corresponding mounting groove. The screw in the first threaded hole can pre-tighten the clutch piezoelectric element. The leg section away from the tibia section is provided with a second threaded hole communicating with the corresponding mounting groove. The screw in the second threaded hole can pre-tighten the drive piezoelectric element.

3. The smooth motion piezoelectric drive device based on the flexible mechanism of a mantis-like forelegs according to claim 2, characterized in that: A first positioning part is fixedly provided on the inner side of the leg section near the fixed end, and the first positioning part can abut against the end of the clutch piezoelectric element away from the first threaded hole.

4. The smooth motion piezoelectric drive device based on the flexible mechanism of a mantis forelegs according to claim 2, characterized in that: A second positioning part is fixedly provided on the inner side of the tibia near the femur, and the second positioning part can abut against the end of the driving piezoelectric element away from the second threaded hole.

5. The piezoelectric drive device for smooth motion based on the flexible mechanism of a mantis forelegs according to claim 1, characterized in that: The fixed end is fixedly installed on the base by screws; the outer side of the fixed end is a smooth arc-shaped structure, and the center of the virtual circle containing the arc-shaped structure on the outer side of the fixed end coincides with the center of the base. The radius of the virtual circle containing the arc-shaped structure on the outer side of the fixed end is the same as the outer diameter of the base.

6. A method for a smooth motion piezoelectric drive device based on the flexible mechanism of a mantis forelegs as described in any one of claims 1 to 5, characterized in that: Includes the following steps: Step 1: In the initial state, the arc-shaped drive leg of the mantis-inspired foreleg flexible mechanism is pre-tightened and self-locked with the rotating shaft. The arc-shaped drive leg is under pre-tightening force. N 0 Deformation occurs under the action of ; Step 2: Apply a set amplitude voltage to the clutch piezoelectric element. V 1 The clutch piezoelectric element extends and pushes the leg joint to rotate outward around the first flexible hinge by an angle. α This causes the tibia, connected to the end of the leg segment, to displace radially outward along the axis. The arc-shaped drive foot at the end of the tibia recovers its deformation, thereby changing the contact preload between the arc-shaped drive foot and the pivot. N 0 ’ By changing the voltage applied to the clutch piezoelectric element V 1 The amplitude is adjusted to achieve active control of the contact state between the arc-shaped drive foot and the rotating shaft; Step 3: Apply a continuous sawtooth wave signal to the driving piezoelectric element. V 2 During the rising edge of the sawtooth wave, the piezoelectric element is driven to extend, pushing the tibia to rotate around the second flexible hinge. β The arc-shaped drive foot drives the rotating shaft to rotate in the positive direction by an angle. And generate deformation to accumulate elastic potential energy; Step 4: During the falling edge of the sawtooth wave, the tibia and the arc-shaped driving foot retract and recover their deformation. At the same time, the arc-shaped driving foot releases elastic potential energy onto the pivot, thereby suppressing the retraction of the pivot under the action of its own inertia and the elastic potential energy of the arc-shaped driving foot. Adjusting the voltage applied to the clutch piezoelectric element V 1 Change contact preload N 0 ’ This changes the amount of elastic potential energy accumulated by the arc-shaped drive foot during the driving process, so that the rotating shaft completely suppresses the backlash and achieves smooth movement.

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