Ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot and control method

Abstract

The present invention discloses an alternating macro-micro piezoelectric robot and control method of ultrasonic stick-slip dual mode, belonging to the field of robot technology, comprising a main body and a foot, wherein the foot is located at the bottom of the main body; the main body comprises a head, a middle part and a tail, and the sides of the head, the middle part and the tail of the main body are provided with longitudinal vibration piezoelectric ceramic sheets, and the longitudinal vibration piezoelectric ceramic sheets are polarized along the thickness direction, wherein on the head and the tail, the longitudinal vibration piezoelectric ceramic sheets on two opposite sides have opposite polarization directions, and on the middle part, the longitudinal vibration piezoelectric ceramic sheets on two opposite sides have the same polarization direction, and on the same side, the two longitudinal vibration piezoelectric ceramic sheets located on the head and the tail respectively have opposite polarization directions; the foot comprises a plurality of foot bodies, the foot bodies are connected to the tail through a boss, and a micro-displacement actuator is provided between the foot bodies and the boss. The present invention combines the characteristics of high precision of stick-slip drive with high speed, large stroke and simple configuration of ultrasonic resonance, and realizes high-energy and high-efficiency drive with coordinated load force and motion speed / precision of the piezoelectric robot.

Description

Technical Field

[0001] The invention relates to the field of robot technology, and in particular to an ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot and a control method. Background Art

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

[0003] With the development and growth of cell manipulation, optical equipment and precision processing technology, the importance of high-precision drive / positioning in integrated circuits, micro-nano manufacturing, life sciences and semiconductor industries has become increasingly prominent. As the common high-end technology core, the stroke, accuracy and other indicators of the precision drive system are also the main factors affecting the performance of related equipment. Traditional drivers used for precision driving are roughly divided into the following categories: voice coil motor, magnetostrictive actuator, piezoelectric / ultrasonic actuator. Among them, piezoelectric / ultrasonic actuator is a micro-nano-scale actuator element that uses the inverse piezoelectric effect to generate displacement by applying voltage. Compared with the first two electromagnetic drive-based methods, piezoelectric / ultrasonic actuators have the characteristics of simple structure, high precision, high resolution, no electromagnetic interference, high energy conversion efficiency, low heat generation, large thrust, fast response and power-off self-locking, etc., which have unique advantages in the field of high-precision drive / positioning technology, and are also increasingly widely used in precision robots, precision positioning platforms, cell puncture, ultra-precision processing and other fields with demanding precision requirements.

[0004] According to the different needs of application scenarios, people have proposed many different structures of piezoelectric actuators. According to the working principle, they are roughly divided into the following categories: ultrasonic piezoelectric actuator, direct-drive piezoelectric actuator, inchworm-type piezoelectric actuator, inertial piezoelectric actuator, each actuator has its own advantages and disadvantages. Inertial piezoelectric actuators are divided into two types, inertial impact type and inertial friction type. Among them, the inertial friction actuator based on the stick-slip principle can obtain micro-nano scale high-precision output at a relatively low voltage, but the stroke is limited by its own deformation and retreat phenomenon, making it difficult to achieve high-speed and large-span motion of the mover or motion platform. The ultrasonic piezoelectric actuator based on the resonance principle has the advantages of high speed, large deformation, and large stroke, but the motion resolution is insufficient to meet the micro-nano scale driving / positioning requirements. Therefore, the problems existing in the prior art (1) A single piezoelectric / ultrasonic actuator is limited by the driving principle and is difficult to take into account the speed, stroke, thrust and micro-nano scale driving / positioning capabilities. (2) Due to structural and weak electromechanical coupling characteristics, traditional clamping and patch piezoelectric / ultrasonic actuators have limited thrust density and power density, poor controllability, and are difficult to miniaturize and modularize. (3) The structure is complex, assembly is difficult, the economic cost is high, the application is limited, and it is not convenient for production, manufacturing, use and maintenance. In view of this, the integration of multiple driving modes is of great significance for improving the fast speed, large thrust, large span, and high-precision comprehensive driving / positioning capabilities of piezoelectric / ultrasonic actuators, and realizing the coordinated complementarity of multiple driving output performances. Summary of the invention

[0005] In view of the above problems, the present invention proposes an ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot and control method, which combines the high precision of stick-slip drive with the high speed, large stroke and simple configuration of ultrasonic resonance, and realizes nanometer-level high-precision drive / positioning in the plane of the piezoelectric robot and centimeter-level high-speed, large-stroke motion and high-load mechanical performance output of multiple driving feet with the same degree of freedom. The macro-micro alternating motion of the piezoelectric robot actuator with high precision / high speed in the plane with two degrees of freedom and rotation is completed, and the high-energy and high-efficiency drive of the piezoelectric robot with coordinated load force and motion speed / precision is realized.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A first aspect of the present invention provides an ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot, comprising a main body and a foot, wherein the foot is located at the bottom of the main body;

[0008] The main body comprises a head, a middle part and a tail part, and longitudinal vibration piezoelectric ceramic sheets are arranged on the side surfaces of the head, middle part and tail part of the main body, and the longitudinal vibration piezoelectric ceramic sheets are polarized along the thickness direction, wherein, on the head part and the tail part, the longitudinal vibration piezoelectric ceramic sheets on two opposite sides have opposite polarization directions, and on the middle part, the longitudinal vibration piezoelectric ceramic sheets on two opposite sides have the same polarization direction, and on the same side, the two longitudinal vibration piezoelectric ceramic sheets respectively located on the head part and the tail part have opposite polarization directions;

[0009] The foot comprises a plurality of foot bodies, the foot bodies are connected to the tail portion via bosses, and a micro-displacement actuator is arranged between the foot bodies and the bosses.

[0010] As a further implementation, the head, middle and tail of the main body are all quadrangular prisms, and the longitudinal vibration piezoelectric ceramic sheets are arranged on the four sides of the quadrangular prism.

[0011] As a further implementation, a countersunk hole is provided on the side surface of the middle part of the main body, and a support rod is fixedly connected inside the countersunk hole. The support rod passes through the longitudinal vibration piezoelectric ceramic piece on the side surface of the middle part of the main body.

[0012] As a further implementation, the foot body corresponds one-to-one to the longitudinal vibration piezoelectric ceramic piece on the tail of the main body.

[0013] As a further implementation method, a cross-shaped groove is provided at the bottom of the tail of the main body, a square boss is left at the center of the cross-shaped groove, the foot body is arranged around the square boss in a centrally symmetrical shape, and a laminated piezoelectric ceramic micro-displacement actuator is provided between the foot body and the boss.

[0014] As a further implementation, the foot body is L-shaped, and a flexible hinge is provided at its inflection point.

[0015] The second aspect of the present invention provides an ultrasonic stick-slip dual-mode alternating macro-micro actuator, based on the ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot described in the first aspect of the present invention, with multiple ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robots as the motion modules of the actuator.

[0016] As a further implementation, the driver includes a carrier platform, the bottom of which is detachably fixedly connected to a plurality of support plates, and the support plates are connected to the support rods of the piezoelectric robot via lower end connecting tube light hole pins.

[0017] As a further implementation, the support platform is a triangular support platform, and each piezoelectric robot is connected to the triangular support platform via four support plates.

[0018] A third aspect of the present invention provides a control method for an ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot, comprising the following steps:

[0019] Determine the moving direction, and give the same sinusoidal voltage to the longitudinal vibration piezoelectric ceramic pieces on opposite sides of the moving direction of the head and the tail to stimulate the bending mode of the robot body;

[0020] A sinusoidal voltage with the same amplitude as the head and tail and a phase difference of π / 2 is given to the longitudinal vibration piezoelectric ceramic pieces on the opposite sides of the moving direction of the middle part to stimulate the tensile mode of the robot body;

[0021] A predetermined excitation voltage is applied to the laminated piezoelectric ceramic micro-displacement actuator in the moving direction of the foot. During the slow voltage rise stage, the micro-displacement actuator on one side stretches in the forward direction and the other side contracts, pushing the foot to slowly move forward in the target direction. During the rapid voltage drop stage, the micro-displacement actuators on both sides quickly return to their original state, and the foot remains stationary due to inertia.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot and control method disclosed in the present invention aims at the problem that a single piezoelectric / ultrasonic actuator is limited by the driving principle and is difficult to take into account the speed, stroke, thrust and micro-nanoscale driving / positioning capabilities, the stick-slip driving speed and stroke are limited, the ultrasonic driving precision is insufficient, and it is difficult to meet the micro-nanoscale driving / positioning requirements. Combining the high precision of stick-slip driving with the high speed, large stroke and simple configuration of ultrasonic resonance, the four-elephant piezoelectric stack is used to achieve nanometer-level high-precision driving / positioning in the plane of the piezoelectric robot, and combined with the bending vibration / longitudinal vibration dual-mode superimposed vibration ultrasonic driving, the piezoelectric robot multi-drive foot is realized with the same degree of freedom of centimeters, large speed, large stroke and high load mechanical performance output, and the actuation assemblability and controllability are improved. On this basis, through the piezoelectric stack stick-slip micro-nano driving and ultrasonic high-speed large-scale time-sharing driving, the macro-micro alternating motion of the piezoelectric robot actuator with high precision / high speed in-plane two-degree-of-freedom movement and rotation is completed, and the high-energy and high-efficiency driving of the piezoelectric robot with coordinated load force and movement speed / precision is realized. In particular, the ultrasonic / stick-slip dual-mode alternating piezoelectric robot involved can be used as a motion module, and a motion platform is formed by arranging / assembling the motion module and the platform plate, and the motion platform is driven to realize its in-plane cross-scale, high-speed, and high-precision macro-micro alternating motion. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 This is a schematic diagram of the overall structure of a piezoelectric robot according to the first embodiment of the present invention;

[0026] Figure 2 It is a structural explosion diagram of the piezoelectric robot according to the first embodiment of the present invention;

[0027] Figure 3 Schematic diagram of vibration modes of a piezoelectric robot according to the first embodiment of the present invention;

[0028] Figure 4 is the "stick-slip" excitation voltage of the piezoelectric robot according to the first embodiment of the present invention;

[0029] Figure 5 It is a schematic diagram of the overall structure of a driver according to the second embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the connection between the bearing platform and the support plate of the driver according to the second embodiment of the present invention;

[0031] Figure 7 It is a front view of a support plate of a driver according to a second embodiment of the present invention;

[0032] Figure 8 for Figure 7 Cross-section along the EE direction.

[0033] Among them, 1. main body; 2. support rod; 3. foot; 31. flexible hinge; 32. connecting tube light hole pin; 33. foot body; 4. longitudinal vibration piezoelectric ceramic piece with hole; 5. longitudinal vibration piezoelectric ceramic piece; 6. micro-displacement actuator; 7. supporting platform; 8. supporting plate; 9. second countersunk hole; 10. gasket; 11. light hole; 12. countersunk hole; 13. cross-shaped groove; 14. boss. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0035] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0036] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0037] Embodiment 1

[0038] like Figure 1-2 As shown, this embodiment provides an ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot, including a main body 1 and a foot 3 , wherein the foot 3 is located at the bottom of the main body 1 .

[0039] The main body 1 includes a head, a middle part and a tail part. The side surfaces of the head, the middle part and the tail part of the main body 1 are provided with longitudinal vibration piezoelectric ceramic sheets 5. The longitudinal vibration piezoelectric ceramic sheets 5 are polarized along the thickness direction. Specifically, on the head part and the tail part, the polarization directions of the longitudinal vibration piezoelectric ceramic sheets 5 on two opposite sides are opposite. On the middle part, the polarization directions of the longitudinal vibration piezoelectric ceramic sheets 4 on two opposite sides are the same. Moreover, on the same side, the two longitudinal vibration piezoelectric ceramic sheets 5 respectively located on the head part and the tail part are opposite in polarization directions.

[0040] The foot 3 includes a plurality of foot bodies 33, and the foot bodies 33 correspond one by one to the longitudinal vibration piezoelectric ceramic sheets 5 on the tail of the main body 1. The foot bodies 33 are connected to the tail through the boss 14, and a micro-displacement actuator 6 is provided between the foot body 22 and the boss 14.

[0041] The head, middle and tail of the main body 1 are all quadrangular prisms, and the longitudinal vibration piezoelectric ceramic sheet 5 is pasted on the four sides of the quadrangular prism through a coupling agent. A countersunk hole 12 is provided on the side of the middle part of the main body 1 inward along the surface, and a support rod 2 is fixedly connected inside the countersunk hole 12, and the support rod 2 passes through the longitudinal vibration piezoelectric ceramic sheet 4 on the side of the middle part of the main body 1. That is, four longitudinal vibration piezoelectric ceramic sheets 4 with holes are pasted on the four surfaces of the middle part of the robot through a coupling agent, and the size is the same as that of the longitudinal vibration piezoelectric ceramic sheet 5, and there is a round hole in the middle reserved for the support rod 2.

[0042] like Figure 2 As shown, a cross-shaped groove 13 is provided at the bottom of the tail of the robot body 1, a square boss 14 is left at the center of the cross-shaped groove 13, and a robot foot body 33 is pasted at the center of the four edges of the square boss 14 through a coupling agent. The foot body 33 is centrally symmetrically arranged around the square boss 14, and four laminated piezoelectric ceramic micro-displacement actuators 6 are fixed between the foot body 33 and the boss 14 by pasting. The foot body 33 is L-shaped, and a flexible hinge 31 is provided at its inflection point, which can amplify the displacement of the robot and ensure that it can move quickly.

[0043] like Figure 3As shown, it is the vibration mode of the robot in the resonance mode in this example. In the resonance mode, when moving in a single direction, different voltages will be applied to the longitudinal vibration piezoelectric ceramic sheets 5 on the opposite sides of the three parts (i.e., the head, middle part, and tail) to stimulate different modes of the robot body 1. A sinusoidal voltage with the same amplitude, frequency, and phase is applied to the longitudinal vibration piezoelectric ceramic sheets 5 on the opposite sides of the head and tail. At this time, one longitudinal vibration piezoelectric ceramic sheet 5 on the same side of the head and tail is stretched and one is contracted, and the opposite side is exactly opposite to this side, thereby stimulating the bending mode of the robot body 1; a sinusoidal voltage with the same amplitude as the head and tail and a phase difference of ±π / 2 is applied to the middle part, and the longitudinal vibration piezoelectric ceramic sheets 5 on both sides of the middle part are contracted or stretched at the same time, stimulating the tensile mode of the robot body 1. The robot produces elliptical motion under the action of two vibrations and performs linear motion along the specified direction. When opposite excitation is applied, the robot moves in the opposite direction. Similarly, applying the voltage as described above to the longitudinal vibration piezoelectric ceramic pieces 5 on the other two opposite sides will cause movement in this direction. By stimulating different piezoelectric ceramic piece groups, rapid positioning movement with two degrees of freedom in the plane can be achieved.

[0044] When a predetermined excitation voltage (i.e., a "stick-slip" excitation voltage) is applied to the multilayer piezoelectric ceramic micro-displacement actuator 6 in the same direction of the tail, the predetermined excitation voltage is as follows: Figure 4 As shown, in the stage of slow voltage rise, the micro-displacement actuator 6 on one side stretches in the forward direction and the other side contracts, pushing the foot 3 to slowly move forward in the target direction; in the stage of rapid voltage drop, the micro-displacement actuators 6 on both sides quickly return to their original state, but due to inertia, the foot 3 remains stationary, thereby realizing a "stick-slip" stepping motion and achieving high-precision resolution micro-displacement.

[0045] Embodiment 2

[0046] like Figure 5 As shown, this embodiment provides an ultrasonic stick-slip dual-mode alternating macro-micro actuator, based on the ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot as described in Example 1 of the present invention, with multiple ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robots as the motion modules of the actuator.

[0047] The driver includes a support platform 7, which is a triangular support platform 7, and the bottom of the triangular support platform 7 is detachably fixedly connected to a plurality of support plates 8, such as Figure 6-8As shown, the triangular support platform 7 is provided with a second countersunk hole 9, which is fixed to the light hole 11 on the support plate 8 by a bolt structure. The support plate 8 is connected to the support rod 2 of the piezoelectric robot through the lower end connecting tube light hole pin 32, and the stability is increased by the gasket 10. Each piezoelectric robot is connected to the triangular support platform 7 through four support plates 8. Relying on the triangular structure, the stability of the platform is guaranteed, and the moving speed and carrying efficiency of the overall platform are guaranteed at the same time. By adjusting the running speed of each driving foot, the platform can move linearly, rotate around the foot, and other movements.

[0048] Embodiment 3

[0049] This embodiment provides a control method for an ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot, comprising the following steps:

[0050] Determine the moving direction, and give the same sinusoidal voltage to the longitudinal vibration piezoelectric ceramic pieces on opposite sides of the moving direction of the head and the tail to stimulate the bending mode of the robot body;

[0051] A sinusoidal voltage with the same amplitude as the head and tail and a phase difference of π / 2 is given to the longitudinal vibration piezoelectric ceramic pieces on the opposite sides of the moving direction of the middle part to stimulate the tensile mode of the robot body;

[0052] A predetermined excitation voltage is applied to the laminated piezoelectric ceramic micro-displacement actuator in the moving direction of the foot. During the slow voltage rise stage, the micro-displacement actuator on one side stretches in the forward direction and the other side contracts, pushing the foot to slowly move forward in the target direction. During the rapid voltage drop stage, the micro-displacement actuators on both sides quickly return to their original state, and the foot remains stationary due to inertia.

[0053] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes, such as changes in the size of the piezoelectric robot, the number of piezoelectric ceramic sheets, the size and shape of the platform, etc. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

[0054] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. An ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot, characterized in that: It comprises a main body and a foot, wherein the foot is located at the bottom of the main body; The main body comprises a head, a middle part and a tail part, and longitudinal vibration piezoelectric ceramic sheets are arranged on the side surfaces of the head, middle part and tail part of the main body, and the longitudinal vibration piezoelectric ceramic sheets are polarized along the thickness direction, wherein, on the head part and the tail part, the longitudinal vibration piezoelectric ceramic sheets on two opposite sides have opposite polarization directions, and on the middle part, the longitudinal vibration piezoelectric ceramic sheets on two opposite sides have the same polarization direction, and on the same side, the two longitudinal vibration piezoelectric ceramic sheets respectively located on the head part and the tail part have opposite polarization directions; The foot part includes a plurality of foot bodies, the foot bodies are connected to the tail part through a boss, and a micro-displacement actuator is provided between the foot bodies and the boss; A cross-shaped groove is provided at the bottom of the tail of the main body, a square boss is left at the center of the cross-shaped groove, the foot body is centrally symmetrically arranged around the square boss, and a laminated piezoelectric ceramic micro-displacement actuator is provided between the foot body and the boss.

2. The ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot according to claim 1, characterized in that: The head, middle and tail of the main body are all quadrangular prisms, and the longitudinal vibration piezoelectric ceramic sheets are arranged on the four sides of the quadrangular prism.

3. The ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot according to claim 1, characterized in that: A countersunk hole is arranged on the side surface of the middle part of the main body, which is inwardly facing the surface. A support rod is fixedly connected inside the countersunk hole. The support rod passes through the longitudinal vibration piezoelectric ceramic piece on the side surface of the middle part of the main body.

4. The ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot according to claim 1, characterized in that: The foot body corresponds one by one to the longitudinal vibration piezoelectric ceramic piece on the tail of the main body.

5. The ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot according to claim 1, characterized in that: The foot body is L-shaped, and a flexible hinge is arranged at the inflection point.

6. An ultrasonic stick-slip dual-mode alternating macro-micro actuator, characterized in that: Based on the ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robot as described in any one of claims 1 to 5, a plurality of ultrasonic stick-slip dual-mode alternating macro-micro piezoelectric robots are used as motion modules of the driver.

7. The ultrasonic stick-slip dual-mode alternating macro-micro actuator according to claim 6, characterized in that: The driver comprises a bearing platform, the bottom of which is detachably and fixedly connected to a plurality of supporting plates, and the supporting plates are connected to the supporting rods of the piezoelectric robot via light hole pins of the lower connecting tubes.

8. The ultrasonic stick-slip dual-mode alternating macro-micro actuator as claimed in claim 7, characterized in that: The supporting platform is a triangular supporting platform, and each piezoelectric robot is connected to the triangular supporting platform via four supporting plates.

9. A control method for an alternating macro-micro piezoelectric robot based on the ultrasonic stick-slip dual mode as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: Determine the moving direction, and give the same sinusoidal voltage to the longitudinal vibration piezoelectric ceramic pieces on opposite sides of the moving direction of the head and the tail to stimulate the bending mode of the robot body; A sinusoidal voltage with the same amplitude as the head and tail and a phase difference of π / 2 is given to the longitudinal vibration piezoelectric ceramic pieces on the opposite sides of the moving direction of the middle part to stimulate the tensile mode of the robot body; A predetermined excitation voltage is applied to the laminated piezoelectric ceramic micro-displacement actuator in the moving direction of the foot. During the slow voltage rise stage, the micro-displacement actuator on one side stretches in the forward direction and the other side contracts, pushing the foot to slowly move forward in the target direction. During the rapid voltage drop stage, the micro-displacement actuators on both sides quickly return to their original state, and the foot remains stationary due to inertia.

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