Surface mount type piezoelectric driving two-degree-of-freedom mechanical arm and driving method thereof

Abstract

The invention provides a patch type piezoelectric driving two-degree-of-freedom mechanical arm and a driving method thereof. The mechanical arm comprises a plurality of unit arm sections connected in sequence and connecting assemblies between the arm sections. During working, driving signals with pi / 2 phase differences are applied to the piezoelectric vibrators on the unit arm sections, so that the points, making contact with the adjacent piezoelectric vibrators, of the piezoelectric vibrators generate micro-amplitude elliptical motion, and driving force is generated through the friction effect; the rotation of the unit arm sections around the piezoelectric vibrators of the adjacent unit arm sections and the rotation of the unit arm sections around the axes of the piezoelectric vibrators of the unit arm sections can be realized respectively, and the two-degree-of-freedom rotation of the two arm sections in two orthogonal planes can be realized due to the fact that the unit arm sections and the adjacent unit arm sections are spatially orthogonal. The mechanical arm is easy to seal, microminiaturization is achieved, electromagnetic interference is avoided, self-locking can be achieved in the power failure process, modal coupling frequency consistency adjustment of different phase modals is not needed, and the limitation on the design size, shape and the like of the mechanical arm is reduced.

Description

Technical Field

[0001] The present invention relates to the field of piezoelectric drive and robots, and in particular to a patch-type piezoelectric drive two-degree-of-freedom robot arm and a driving method thereof. Background Art

[0002] The development and utilization of marine resources has always been the focus of research in countries around the world. In this field, underwater robots are regarded as an important modern tool. In many cases, traditional hydraulic or motor-driven industrial-grade operating manipulators are widely used in cabled underwater robots to support the exploration and development of marine resources. However, with the continuous development of technology, small cable-free autonomous underwater robots have also begun to attract attention because they have greater flexibility and adaptability and can perform tasks in a wider range of marine environments.

[0003] Although traditional hydraulic or motor-driven robotic arms excel in some aspects, they also have some limitations. One of them is that they are bulky, which can be a problem in miniaturized autonomous underwater robots. In addition, these traditional robotic arms usually require a lot of energy, which can be impractical for small robots. Summary of the invention

[0004] In order to solve the problems of the prior art, the present invention provides a patch-type piezoelectric driven two-degree-of-freedom robotic arm and a driving method thereof, which have a simple structure, light weight, no need for gear reduction mechanisms, are easy to seal, easy to achieve miniaturization, have low operating noise, are easy to achieve low-speed and high torque, are not subject to electromagnetic interference, and can self-lock when power is off; they are easier to achieve serialization and modular design, and the robotic arm has many adjustable sizes depending on the engineering application scenarios, has strong engineering applicability, and has important application prospects.

[0005] The present invention adopts the following technical solutions to solve the above technical problems: A patch-type piezoelectric driven two-degree-of-freedom mechanical arm comprises a plurality of N+1 unit arm sections and N connection components, wherein N is a natural number greater than or equal to 1, and the N+1 unit arm sections are sequentially connected through the connection components.

[0006] The unit arm section is also a piezoelectric vibrator, including a connecting plate, a metal substrate and first to fourth piezoelectric ceramic sheets, specifically including a first connecting plate, a second connecting plate, and a first piezoelectric ceramic sheet, a second piezoelectric ceramic sheet, a third piezoelectric ceramic sheet, and a fourth piezoelectric ceramic sheet.

[0007] The metal matrix includes a first stepped cylinder, a second stepped cylinder, and a third stepped cylinder, wherein the diameters of the first stepped cylinder and the third stepped cylinder are equal and larger than the diameter of the second stepped cylinder; the two end faces of the second stepped cylinder are respectively fixedly connected to one end face of the first stepped cylinder and one end face of the third stepped cylinder, and the first to third stepped cylinders are coaxial.

[0008] The first connecting plate and the second connecting plate are arranged in parallel and connected through a metal matrix. Two rectangular patch slots are respectively arranged on both sides of the center of the first connecting plate and the second connecting plate, for a total of four rectangular patch slots.

[0009] The first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet, and the fourth piezoelectric ceramic sheet are respectively pasted in the four rectangular patch grooves. The first piezoelectric ceramic sheet and the fourth piezoelectric ceramic sheet have the same polarization direction, which is opposite to the polarization direction of the second piezoelectric ceramic sheet and the third piezoelectric ceramic sheet and are parallel to each other. The second piezoelectric ceramic sheet and the third piezoelectric ceramic sheet have the same polarization direction, which is opposite to the polarization direction of the first piezoelectric ceramic sheet and the fourth piezoelectric ceramic sheet and are parallel to each other.

[0010] The first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet and the fourth piezoelectric ceramic sheet are used to input an external driving signal to make the metal substrate vibrate.

[0011] The connecting component comprises a first sliding bearing semicircular ring, a second sliding bearing semicircular ring, a third sliding bearing semicircular ring, a fourth sliding bearing semicircular ring, a first double-hook spring, a second double-hook spring, a third double-hook spring, and a fourth double-hook spring.

[0012] The first sliding bearing semicircular ring, the second sliding bearing semicircular ring, the third sliding bearing semicircular ring and the fourth sliding bearing semicircular ring are all semicircular in shape, and the end points of the semicircular rings extend outward perpendicularly to the center of the circle, and the extended parts are provided with a first connecting hole and a second connecting hole that penetrate through them; the directions of the spring hooks at both ends of the first double-hook spring, the second double-hook spring, the third double-hook spring and the fourth double-hook spring are perpendicular to each other.

[0013] One end of the first double-hook spring and the second double-hook spring are connected to the first connecting hole and the second connecting hole of the first sliding bearing semicircular ring, respectively, and the other end is connected to the first connecting hole of the third sliding bearing semicircular ring and the fourth sliding bearing semicircular ring, respectively; one end of the third double-hook spring and the fourth double-hook spring are connected to the first connecting hole and the second connecting hole of the second sliding bearing semicircular ring, respectively, and the other end is connected to the second connecting hole of the third sliding bearing semicircular ring and the fourth sliding bearing semicircular ring, respectively; so that the planes where the first sliding bearing semicircular ring and the second sliding bearing semicircular ring are parallel to each other, the planes where the third sliding bearing semicircular ring and the fourth sliding bearing semicircular ring are parallel to each other, and the planes where the first sliding bearing semicircular ring and the third sliding bearing semicircular ring are perpendicular to each other; When the unit arm section and its adjacent unit arm section are connected through a connecting assembly, the first sliding bearing sleeve and the second sliding bearing sleeve of the connecting assembly are clearance-fitted on the second step cylinder of the metal matrix of the unit arm section, and the third sliding bearing sleeve and the fourth sliding bearing sleeve of the connecting assembly are clearance-fitted on the second step cylinder of the metal matrix of the adjacent unit arm section, so that the first step cylinder and the third step cylinder of the metal matrix of the unit arm section and the first step cylinder and the third step cylinder of the metal matrix of the adjacent unit arm section are orthogonally abutted against each other.

[0014] As a further optimization scheme of a patch-type piezoelectric-driven two-degree-of-freedom robotic arm of the present invention, the first piezoelectric ceramic sheet, the second piezoelectric ceramic sheet, the third piezoelectric ceramic sheet, and the fourth piezoelectric ceramic sheet are bonded to the rectangular patch grooves on both sides of the center of the first connecting plate and the second connecting plate by epoxy resin glue, and are insulated with waterproof glue.

[0015] As a further optimization scheme of the patch-type piezoelectric driven two-degree-of-freedom robotic arm of the present invention, the metal substrate is provided with a gasket along its axis, and the end of the first step cylinder away from the second step cylinder and the end of the third step cylinder away from the second step cylinder are both provided with a gasket coaxial with the second step cylinder.

[0016] As a further optimization solution of the patch-type piezoelectric driven two-degree-of-freedom mechanical arm of the present invention, both ends of the first connecting plate and the second connecting plate are provided with symmetrical mounting circular holes, and both sides of the middle are provided with symmetrical rectangular patch grooves.

[0017] Both ends of the first connecting plate and the second connecting plate are respectively connected through interference fit with the second stepped cylinders of the two unit arm sections through their mounting circular holes.

[0018] The present invention also discloses a unit arm segment driving method of the patch-type piezoelectric driven two-degree-of-freedom mechanical arm, comprising the following steps: A first simple harmonic driving signal is applied to the first piezoelectric ceramic plate and the second piezoelectric ceramic plate of the unit arm section, and a second simple harmonic driving signal with the same frequency as the first simple harmonic driving signal and a time phase difference of π / 2 is applied to the third piezoelectric ceramic plate and the fourth piezoelectric ceramic plate of the unit arm section, so as to stimulate two first-order longitudinal vibration modes of the piezoelectric vibrator that are mutually orthogonal in time and space, so that each point at both ends of the metal substrate produces a slight elliptical motion, and the piezoelectric vibrators of adjacent unit arm sections provide support to it to generate friction force, and a driving force is generated through the friction, so that each unit arm section rotates relative to its adjacent unit arm section.

[0019] The beneficial effects of the present invention are as follows: compared with traditional electromagnetic and hydraulic press driven robotic arms, the present invention has a simple structure, light weight, no need for gear reduction mechanisms, is easy to seal, easy to achieve miniaturization, has low operating noise, is easy to achieve low-speed and high torque, is not subject to electromagnetic interference, and can self-lock when power is off; it is easier to achieve serialization and modular design, and the robotic arm can have many adjustable sizes depending on the engineering application scenario, has strong engineering applicability, and has important application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic structural diagram of a patch-type piezoelectric driven two-degree-of-freedom robotic arm provided by an embodiment of the present invention; Figure 2 A schematic diagram of a unit arm section structure provided by an embodiment of the present invention; Figure 3 A schematic diagram of the detailed structure of a unit arm section provided in an embodiment of the present invention; Figure 4 A schematic diagram of the structure of a connecting plate provided in an embodiment of the present invention; Figure 5 A schematic diagram of the structure of a metal substrate provided by an embodiment of the present invention; Figure 6 A schematic diagram of the decomposed structure of a metal matrix provided in an embodiment of the present invention; Figure 7 A schematic diagram of the structure of a connection assembly provided in an embodiment of the present invention; Figure 8 A schematic structural diagram of a sliding bearing sleeve of a connecting assembly provided in an embodiment of the present invention; Fig. 9 A schematic diagram of applied voltage signals for the first to fourth piezoelectric ceramic sheets provided in an embodiment of the present invention; Fig.10 A schematic diagram of the first-order longitudinal vibration mode of a piezoelectric vibrator along the Z axis provided by an embodiment of the present invention; The reference numerals in the accompanying drawings represent: 1-first unit arm section, 2-second unit arm section, 3-third unit arm section, 4-piezoelectric vibrator, 5-metal substrate, 6.1-first connecting plate, 6.2-second connecting plate, 7.1-first piezoelectric ceramic sheet, 7.2-second piezoelectric ceramic sheet, 7.3-third piezoelectric ceramic sheet, 7.4-fourth piezoelectric ceramic sheet, 8-rectangular patch groove, 9-mounting circular hole on the connecting plate, 10-first stepped cylinder, 11-second stepped cylinder, 1 2-third stepped cylinder, 13-nut, 14-connecting plate, 15-gasket, 16-metal base, 17.1-first sliding bearing ring sleeve, 17.2-second sliding bearing ring sleeve, 17.3-third sliding bearing ring sleeve, 17.4-fourth sliding bearing ring sleeve, 18.1-first double hook spring, 18.2-second double hook spring, 18.3-third double hook spring, 18.4-fourth double hook spring, 19.1-first connecting hole, 19.2-second connecting hole. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, the present invention discloses a patch-type piezoelectric driven two-degree-of-freedom robotic arm, comprising a number of N+1 unit arm sections and N connecting components, N being a natural number greater than or equal to 1, and the N+1 unit arm sections are sequentially connected through the N connecting components.

[0024] like Figure 2 , 3As shown, the unit arm section, i.e., a piezoelectric vibrator, comprises a first connecting plate 6.1, a second connecting plate 6.2, and a metal substrate 5; the first connecting plate 6.1 and the second connecting plate 6.2 each comprise a first piezoelectric ceramic sheet 7.1, a second piezoelectric ceramic sheet 7.2, a third piezoelectric ceramic sheet 7.3, and a fourth piezoelectric ceramic sheet 7.4; the first piezoelectric ceramic sheet 7.1, the second piezoelectric ceramic sheet 7.2, the third piezoelectric ceramic sheet 7.3, and the fourth piezoelectric ceramic sheet 7.4 are respectively pasted on four rectangular stickers of the first connecting plate 6.1 and the second connecting plate 6.2 In the sheet slot, the first piezoelectric ceramic sheet 7.1 and the fourth piezoelectric ceramic sheet 7.4 have the same polarization direction, which is opposite to the polarization direction of the second piezoelectric ceramic sheet 7.2 and the third piezoelectric ceramic sheet 7.3 and are parallel to each other; the second piezoelectric ceramic sheet 7.2 and the third piezoelectric ceramic sheet 7.3 have the same polarization direction, which is opposite to the polarization direction of the first piezoelectric ceramic sheet 7.1 and the fourth piezoelectric ceramic sheet 7.4 and are parallel to each other; the first piezoelectric ceramic sheet 7.1, the second piezoelectric ceramic sheet 7.2, the third piezoelectric ceramic sheet 7.3 and the fourth piezoelectric ceramic sheet 7.4 are used to input an external driving signal to make the metal substrate vibrate. The first connecting plate 6.1 and the second connecting plate 6.2 are arranged in parallel; like Figure 4 As shown, the connecting plate includes a first piezoelectric ceramic sheet 7.1, a second piezoelectric ceramic sheet 7.2, a third piezoelectric ceramic sheet 7.3, and a fourth piezoelectric ceramic sheet 7.4, and both ends of the connecting plate are provided with symmetrical mounting circular holes 9, and the middle is provided with a rectangular hole 8; the first piezoelectric ceramic sheet 7.1, the second piezoelectric ceramic sheet 7.2, the third piezoelectric ceramic sheet 7.3, and the fourth piezoelectric ceramic sheet 7.4 are bonded to the rectangular patch grooves 8 on both sides of the center of the first connecting plate 6.1 and the second connecting plate 6.2 by epoxy resin glue, and are insulated with waterproof glue.

[0025] like Figure 5 , 6 As shown, the metal matrix comprises a first stepped cylinder 10, a second stepped cylinder 11, and a third stepped cylinder 12, wherein the diameters of the first stepped cylinder 10 and the third stepped cylinder 12 are equal and larger than the diameter of the second stepped cylinder 11; the two end faces of the second stepped cylinder 11 are respectively fixedly connected to one end face of the first stepped cylinder 10 and one end face of the third stepped cylinder 12, and the first to third stepped cylinders are coaxial; the metal matrix is ​​in accordance with Figure 6 Connections shown.

[0026] like Figure 7 , 8As shown, the connecting assembly comprises a first sliding bearing semicircular ring 17.1, a second sliding bearing semicircular ring 17.2, a third sliding bearing semicircular ring 17.3, a fourth sliding bearing semicircular ring 17.4, a first double-hook spring 18.1, a second double-hook spring 18.2, a third double-hook spring 18.3, and a fourth double-hook spring 18.4; the first sliding bearing semicircular ring 17.1, the second sliding bearing semicircular ring 17.2, the third sliding bearing semicircular ring 17.3, and the fourth sliding bearing semicircular ring 17.4 are all semicircular, and the semicircular end points extend outward perpendicular to the center of the circle, and the extension is provided with a first penetrating The first double hook spring 18.1, the second double hook spring 18.2, the third double hook spring 18.3, and the fourth double hook spring 18.4 have spring hooks at both ends that are perpendicular to each other; one end of the first double hook spring 18.1 and the second double hook spring 18.2 are respectively connected to the first connecting hole 19.1 and the second connecting hole 19.2 of the first sliding bearing semicircular ring 17.1, and the other end is respectively connected to the first connecting hole 19.1 of the third sliding bearing semicircular ring 17.3 and the fourth sliding bearing semicircular ring 17.4; the third double hook spring 18.3 and the fourth double hook spring 18.4 have spring hooks at both ends that are perpendicular to each other; one end of the first double hook spring 18.1 and the second double hook spring 18.2 are respectively connected to the first connecting hole 19.1 and the second connecting hole 19.2 of the first sliding bearing semicircular ring 17.1, and the other end is respectively connected to the first connecting hole 19.1 of the third sliding bearing semicircular ring 17.3 and the fourth sliding bearing semicircular ring 17.4; One end of the double hook spring 18.4 is respectively connected to the first connecting hole 19.1 and the second connecting hole 19.2 of the second sliding bearing semicircular ring 17.2, and the other end is respectively connected to the second connecting hole 19.2 of the third sliding bearing semicircular ring 17.3 and the fourth sliding bearing semicircular ring 17.4; so that the planes where the first sliding bearing semicircular ring 17.1 and the second sliding bearing semicircular ring 17.2 are parallel to each other, the planes where the third sliding bearing semicircular ring 17.3 and the fourth sliding bearing semicircular ring 17.4 are parallel to each other, and the planes where the first sliding bearing semicircular ring 17.1 and the third sliding bearing semicircular ring 17.3 are parallel to each other. Perpendicular to each other; when the unit arm section and its adjacent unit arm section are connected through a connecting assembly, the first sliding bearing sleeve 17.1 and the second sliding bearing sleeve 17.2 of the connecting assembly are clearance-fitted on the second stepped cylinder 11 of the metal matrix of the unit arm section, and the third sliding bearing sleeve 17.3 and the fourth sliding bearing sleeve 17.4 of the connecting assembly are clearance-fitted on the second stepped cylinder 11 of the metal matrix of the adjacent unit arm section, so that the first stepped cylinder 10 and the third stepped cylinder 12 of the metal matrix of the unit arm section and the first stepped cylinder 10 and the third stepped cylinder 12 of the metal matrix of the adjacent unit arm section are orthogonal to each other.

[0027] The present invention also discloses a unit arm segment driving method of the patch-type piezoelectric driven two-degree-of-freedom mechanical arm, comprising the following steps: like Fig. 9As shown, a first simple harmonic driving signal is applied to the first piezoelectric ceramic plate 7.1 and the second piezoelectric ceramic plate 7.2 of the unit arm section, and a second simple harmonic driving signal with the same frequency as the first simple harmonic driving signal and a time phase difference of π / 2 is applied to the third piezoelectric ceramic plate 7.3 and the fourth piezoelectric ceramic plate 7.4 of the unit arm section, so as to stimulate two first-order longitudinal vibration modes of the piezoelectric vibrator that are orthogonal to each other in time and space, so that each point at both ends of the metal substrate produces a slight elliptical motion, and the piezoelectric vibrators of adjacent unit arm sections provide support for it to generate friction force, and the driving force is generated through the friction, so that the unit arm section rotates relative to its adjacent unit arm section.

[0028] Fig.10 A schematic diagram of the first-order longitudinal vibration mode of a piezoelectric vibrator along the Z-axis provided in an embodiment of the present invention.

[0029] When working, driving signals can be applied to the piezoelectric vibrators of adjacent unit arm sections respectively, which can realize the rotation of the unit arm section around the circumferential direction of the adjacent unit arm section and the rotation of the unit arm section around the axis of its own metal substrate. Since the unit arm section and its adjacent unit arm section are orthogonal in space, applying driving signals to the piezoelectric vibrators corresponding to the two unit arm sections can realize the two-degree-of-freedom rotation of the two arm sections in the orthogonal plane.

[0030] The present invention proposes a patch-type piezoelectric driven two-degree-of-freedom robotic arm and a driving method thereof. Compared with a traditional operating robotic arm, it has a simple structure, light weight, is easy to achieve miniaturization and sealing, is not subject to electromagnetic interference, and can self-lock when power is off. It has important application prospects for the operating robotic arm of a micro robot.

[0031] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, the above is only a preferred embodiment of the present invention. Since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field is within the technical scope disclosed by the present invention. For ordinary technicians in the technical field, changes or replacements that can be easily thought of should be covered within the protection scope of the present invention without departing from the principle of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A patch-type piezoelectric driven two-degree-of-freedom robotic arm, characterized in that: It comprises N+1 unit arm sections and N connection components, where N is a natural number greater than or equal to 1, and the N+1 unit arm sections are sequentially connected through the connection components; The unit arm section is a piezoelectric vibrator (4), comprising a first connecting plate (6.1), a second connecting plate (6.2), and a first piezoelectric ceramic sheet (7.1), a second piezoelectric ceramic sheet (7.2), a third piezoelectric ceramic sheet (7.3), and a fourth piezoelectric ceramic sheet (7.4); the first connecting plate (6.1) and the second connecting plate (6.2) are arranged in parallel and connected at both ends via a metal matrix; two rectangular patch grooves (8) are respectively arranged on both sides of the center of the first connecting plate (6.1) and the second connecting plate (6.2), for a total of four rectangular patch grooves; the first piezoelectric ceramic sheet (7.1), The second piezoelectric ceramic sheet (7.2), the third piezoelectric ceramic sheet (7.3), and the fourth piezoelectric ceramic sheet (7.4) are respectively pasted in the four rectangular patch grooves (8); the first piezoelectric ceramic sheet (7.1) and the fourth piezoelectric ceramic sheet (7.4) have the same polarization direction, which is opposite to the polarization direction of the second piezoelectric ceramic sheet (7.2) and the third piezoelectric ceramic sheet (7.3), and are parallel to each other; the second piezoelectric ceramic sheet (7.2) and the third piezoelectric ceramic sheet (7.3) have the same polarization direction, which is opposite to the polarization direction of the first piezoelectric ceramic sheet (7.1) and the fourth piezoelectric ceramic sheet (7.4), and are parallel to each other; The connecting assembly comprises a first sliding bearing semicircular ring (17.1), a second sliding bearing semicircular ring (17.2), a third sliding bearing semicircular ring (17.3), a fourth sliding bearing semicircular ring (17.4), a first double-hook spring (18.1), a second double-hook spring (18.2), a third double-hook spring (18.3), and a fourth double-hook spring (18.4); the first sliding bearing semicircular ring (17.1), the second sliding bearing semicircular ring (17.2), the third sliding bearing semicircular ring (17.3), and the fourth double-hook spring (18.4); 3) The fourth sliding bearing semicircular ring (17.4) is semicircular in shape, and the semicircular end point extends outward perpendicularly to the center of the circle, and a first connecting hole (19.1) and a second connecting hole (19.2) are provided at the extension; the directions of the spring hooks at both ends of the first double hook spring (18.1), the second double hook spring (18.2), the third double hook spring (18.3), and the fourth double hook spring (18.4) are perpendicular to each other; one end of the first double hook spring (18.1) and the second double hook spring (18.2) are respectively One end of the third double-hook spring (18.3) and the fourth double-hook spring (18.4) are connected to the first connecting hole (19.1) and the second connecting hole (19.2) of the first sliding bearing semicircular ring (17.1), respectively, and the other end is connected to the first connecting hole (19.1) of the third sliding bearing semicircular ring (17.3) and the fourth sliding bearing semicircular ring (17.4), respectively; one end of the third double-hook spring (18.3) and the fourth double-hook spring (18.4) are connected to the first connecting hole (19.1) and the second connecting hole (19.2) of the second sliding bearing semicircular ring (17.2), respectively, and the other end is connected to the first connecting hole (19.1) and the second connecting hole (19.2) of the second sliding bearing semicircular ring (17.2), respectively. The ends are respectively connected to the second connecting holes (19.2) of the third sliding bearing semicircular ring (17.3) and the fourth sliding bearing semicircular ring (17.4); so that the planes where the first sliding bearing semicircular ring (17.1) and the second sliding bearing semicircular ring (17.2) are located are parallel to each other, the planes where the third sliding bearing semicircular ring (17.3) and the fourth sliding bearing semicircular ring (17.4) are located are parallel to each other, and the planes where the first sliding bearing semicircular ring (17.1) and the third sliding bearing semicircular ring (17.3) are located are perpendicular to each other; When the unit arm section and its adjacent unit arm section are connected via a connecting assembly, the first sliding bearing ring sleeve (17.1) and the second sliding bearing ring sleeve (17.2) of the connecting assembly are clearance-matched on the metal base of the unit arm section, and the third sliding bearing ring sleeve (17.3) and the fourth sliding bearing ring sleeve (17.4) of the connecting assembly are clearance-matched on the metal base of the adjacent unit arm section, so that the metal base of the unit arm section and the metal base of the adjacent unit arm section are orthogonally abutted against each other.

2. The patch-type piezoelectric driven two-degree-of-freedom mechanical arm according to claim 1, characterized in that: The first piezoelectric ceramic sheet (7.1), the second piezoelectric ceramic sheet (7.2), the third piezoelectric ceramic sheet (7.3) and the fourth piezoelectric ceramic sheet (7.4) are bonded to the rectangular patch grooves (8) on both sides of the center of the first connecting plate (6.1) and the second connecting plate (6.2) by epoxy resin glue, and are insulated by waterproof glue.

3. The patch-type piezoelectric driven two-degree-of-freedom mechanical arm according to claim 1, characterized in that: The metal base is provided with a gasket along its axis, and one end of the first stepped cylinder (10) away from the second stepped cylinder (11) and one end of the third stepped cylinder (12) away from the second stepped cylinder (11) are both provided with a gasket coaxial with the second stepped cylinder (11).

4. The patch-type piezoelectric driven two-degree-of-freedom mechanical arm according to claim 1, characterized in that: The metal matrix comprises a first stepped cylinder (10), a second stepped cylinder (11), and a third stepped cylinder (12), wherein the diameters of the first stepped cylinder (10) and the third stepped cylinder (12) are equal and greater than the diameter of the second stepped cylinder (11); two end faces of the second stepped cylinder (11) are respectively fixedly connected to an end face of the first stepped cylinder (10) and an end face of the third stepped cylinder (12), and the first to third stepped cylinders are coaxial.

5. The patch-type piezoelectric driven two-degree-of-freedom mechanical arm according to claim 4, characterized in that: Both ends of the first connecting plate (6.1) and the second connecting plate (6.2) are provided with symmetrical mounting circular holes (9), and both sides of the middle are provided with symmetrical rectangular patch grooves (8); both ends of the first connecting plate (6.1) and the second connecting plate (6.2) are respectively connected by interference fit through their mounting circular holes (9) and the second stepped cylinders (11) of the two unit arm sections.

6. The patch-type piezoelectric driven two-degree-of-freedom mechanical arm according to claim 4, characterized in that: When the unit arm section and its adjacent unit arm section are connected via a connecting assembly, the first sliding bearing ring sleeve (17.1) and the second sliding bearing ring sleeve (17.2) of the connecting assembly are clearance-fitted on the second stepped cylinder (11) of the metal base of the unit arm section, and the third sliding bearing ring sleeve (17.3) and the fourth sliding bearing ring sleeve (17.4) of the connecting assembly are clearance-fitted on the second stepped cylinder (11) of the metal base of the adjacent unit arm section, so that the first stepped cylinder (10) and the third stepped cylinder (12) of the metal base of the unit arm section and the first stepped cylinder (10) and the third stepped cylinder (12) of the metal base of the adjacent unit arm section are orthogonally abutted against each other.

7. A method for driving a patch-type piezoelectric driven two-degree-of-freedom robotic arm as claimed in any one of claims 1 to 6, characterized in that The following steps are involved: A first simple harmonic drive signal is applied to the first piezoelectric ceramic plate (7.1) and the second piezoelectric ceramic plate (7.2) of the unit arm section, and a second simple harmonic drive signal with the same frequency as the first simple harmonic drive signal and a time phase difference of π / 2 is applied to the third piezoelectric ceramic plate (7.3) and the fourth piezoelectric ceramic plate (7.4) of the unit arm section, so as to stimulate two first-order longitudinal vibration modes of the piezoelectric vibrator that are mutually orthogonal in time and space, so that each point at both ends of the metal substrate generates a slight elliptical motion, and the piezoelectric vibrators of adjacent unit arm sections provide support for it to generate friction force, and a driving force is generated through the friction action, so that the unit arm section rotates relative to its adjacent unit arm section.

Images