WO2023134185A1

WO2023134185A1 - Mechanical arm based on minimum energy structure of dielectric elastomer

Info

Publication number: WO2023134185A1
Application number: PCT/CN2022/118020
Authority: WO
Inventors: 张庭; 李阳; 宁传新; 巩振华; 李轩
Original assignee: 苏州大学
Priority date: 2022-01-12
Filing date: 2022-09-09
Publication date: 2023-07-20
Also published as: CN114367966A

Abstract

Provided is a mechanical arm based on the minimum energy structure of a dielectric elastomer. The mechanical arm comprises a plurality of rigid origami mechanisms (10), which are connected in series. Each rigid origami mechanism (10) is substantially cylindrical and comprises two support bodies (1) and a plurality of rigid origami elements (2), wherein first creases (11) are formed at joints between the rigid origami elements (2) and the support bodies (1), and an actuating assembly (3) is correspondingly provided for each first crease (11). The actuating assembly (3) comprises a minimum energy structure type dielectric elastomer actuator. The actuating assembly (3) has two connecting ends, which can approach or move away from each other after the actuating assembly (3) is bent, wherein one connecting end of the actuating assembly (3) is a movable end, and the distance between the movable end of the actuating assembly (3) and the first crease (11) corresponding thereto can change with the bending of the actuating assembly (3); and the other connecting end of the actuating assembly (3) is a fixed end, and the distance between the fixed end of the actuating assembly (3) and the first crease (11) corresponding thereto is set to be fixed. The mechanical arm has multiple degrees of freedom, good flexibility, a high response speed, a larger actuating force, and high environmental adaptability.

Description

Manipulator Based on Dielectric Elastomer Minimum Energy Structure

technical field

The invention belongs to the technical field of intelligent robots, and in particular relates to a mechanical arm based on a dielectric elastic body minimum energy structure.

Background technique

Most of the existing robotic arms are made of rigid materials, driven by motors or hydraulic pressure, capable of outputting large loads, replacing humans in some extreme environments. However, the immutability of rigid materials limits the environmental adaptation of robotic arms Therefore, there is an urgent need for a new type of flexible manipulator with the ability to adapt to complex environments. The dielectric elastomer material has the characteristics of large driving strain, high energy density, high energy conversion efficiency, and fast response speed, and is more suitable for the drive of flexible manipulators. In addition, in recent years, origami structures have attracted widespread attention due to their good folding characteristics and large folding-to-expansion ratio. Applying origami technology to the design of robotic arms can increase its adaptability to the environment.

The Chinese invention patent with the patent authorization announcement number CN105856271B discloses an aeronautical mechanical arm based on shape memory polymer and dielectric elastomer and its manufacturing method. The mechanical arm of this invention does not rely on complex mechanical structures, and its deployment mainly depends on the shape memory effect of shape memory polymers and the self-stretching properties of dielectric elastomers under voltage. It has low density and can withstand large deformations. The front is compressed and stored to reduce the space occupied and the payload during launch. The extension of the above-mentioned mechanical arm is driven by a mixture of shape memory polymer and dielectric elastomer, and the amount of extension is difficult to achieve precise control, and the driving force is relatively small.

Referring to the paper "Soft pneumatic actuator-driven origami-inspired modular robotic "pneumagami".", the article introduces a new modular robot for reconfigurable, actively controlled, high degrees of freedom (high freedom degree) systems, such as linear assembly to form a continuous robotic arm. The above-mentioned modular robot is driven by a pneumatic soft bag, has many pneumatic auxiliary components, and has a relatively complicated structure.

The Chinese invention patent with publication (publication) number CN112959346A discloses a rigid origami-style dexterous hand modular drive knuckle driven by a dielectric elastomer. The phalanx of the invention is driven by a multi-layer curved dielectric elastomer driver, which has multiple degrees of freedom, good flexibility, and fast response speed. The origami structure improves the rigidity and load capacity of the phalanx, and the dielectric elastomer material itself The flexibility combined with the folding properties of the origami structure improves the environmental adaptability of the knuckles. The above-mentioned phalanx has the following disadvantages: ①The driving force is small; ②The bending angle of the phalanx is difficult to control; ③When the phalanx is compressed or bent, the deformation of the two connected origami units is difficult to predict, which may interfere with the driver and damage the finger. knuckle movement; ④When the knuckle length changes, the multilayer curved dielectric elastomer actuator also needs to be designed longer, which has poor versatility.

Contents of the invention

In view of the above-mentioned deficiencies in the prior art, the present invention provides a mechanical arm based on a dielectric elastomer minimum energy structure with multiple degrees of freedom, good flexibility, fast response, strong environmental adaptability, and greater driving force.

The present invention provides the following technical solutions: a mechanical arm based on a dielectric elastomer minimum energy structure, the mechanical arm includes a plurality of rigid origami mechanisms connected in series, and the rigid origami mechanisms are in the shape of a cylinder as a whole, including Two support bodies arranged at both ends of the cylinder and a plurality of rigid origami evenly distributed around the center line of the cylinder, the first crease is formed at the junction of the rigid origami and the support body, and each The first crease is correspondingly provided with a drive assembly, the drive assembly includes a minimum energy structure type dielectric elastomer driver, the drive assembly has two connection ends that can approach or move away from each other after bending, the two connection ends of the drive assembly The ends are respectively connected to form the rigid origami and the support body corresponding to the first crease, one of the connecting ends of the drive assembly is a moving end, and the distance between the moving end of the drive assembly and the corresponding first crease can be The other connecting end of the driving assembly is a fixed end, and the distance between the fixed end of the driving assembly and the corresponding first crease is fixed, and the bending of the driving assembly drives The angle of the corresponding first crease changes, and the change of the angle of the first crease drives the deformation of the rigid origami forming the first crease, and the deformation of the rigid origami drives the bending or the change of the length of the cylinder.

In an embodiment of the present invention, the drive assembly further includes a first rigid support part and a second rigid support part, and the first rigid support part and the second rigid support part are respectively connected to the minimum energy structural dielectric The elastic body driver serves as the moving end and the fixed end of the driving assembly respectively.

In one embodiment of the present invention, when the drive assembly is not powered on, the drive assembly is in a bent state with an arch height of H1, and the first crease angle corresponding to the drive assembly is α1. When the drive assembly is powered on, the drive assembly The assembly is in a bent state or a flat state and has an arched height of H2, the corresponding first crease angle of the driving assembly is α2, H1 is larger than H2, and α1 is smaller than α2.

In one embodiment of the present invention, the minimum energy structural dielectric elastomer actuator includes a flexible substrate, a pre-stretched dielectric elastomer film disposed on the flexible substrate, and a pre-stretched dielectric elastomer film uniformly coated on the pre-stretched Flexible electrodes on both sides of a dielectric elastomer film.

In one embodiment of the present invention, the pre-stretched dielectric elastomer film is made of polyacrylate, natural rubber or silica gel, and the flexible electrode is made of carbon grease, single-walled carbon nanotube or silver nanowire conductive liquid.

In one embodiment of the present invention, the moving end of the driving assembly is movably connected in a long hole through a pin shaft and a baffle, the pin shaft passes through the long hole, and the two ends of the pin shaft are respectively connected to the drive assembly and the baffle.

In one embodiment of the present invention, the moving direction of the moving end of the driving assembly is perpendicular to the corresponding first crease.

In one embodiment of the present invention, the fixed end of the driving assembly is fixed by adhesive.

In an embodiment of the present invention, the moving end of the driving assembly is connected to the rigid origami, and the fixed end of the driving assembly is connected to the support body.

In an embodiment of the present invention, only one second crease is provided on the rigid origami, and the second crease is a single-vertex multi-crease pattern.

Due to the use of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art:

1) The mechanical arm based on the minimum energy structure of the dielectric elastomer disclosed in the present invention adopts rigid origami and a minimum energy structure dielectric elastomer driver, which has multiple degrees of freedom, good flexibility, fast response speed, and greater driving force. Strong environmental adaptability;

2) For the mechanical arm based on the minimum energy structure of the dielectric elastomer disclosed in the present invention, the driving component is set at the first crease between the rigid origami and the support body, and the rigid origami can be controlled only by controlling the angle at the crease The movement of the mechanism is easy to control, and can be used to drive rigid origami mechanisms of various sizes, and has strong versatility.

3) The mechanical arm based on the minimum energy structure of the dielectric elastomer disclosed in the present invention is composed of multiple rigid origami mechanisms in series, and each rigid origami mechanism is controlled independently, so the operation of the mechanical arm is more flexible and the range of motion is wider. Environmental adaptability is stronger.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application, and do not constitute an improper limitation of the present application.

Fig. 1 is the overall schematic diagram of mechanical arm among the present invention;

Fig. 2 is the overall schematic diagram of rigid origami mechanism in the present invention;

Fig. 3 is a schematic diagram of the connection between the support body of the rigid origami mechanism and the rigid origami in the present invention;

Fig. 4 is the schematic diagram of driving assembly in the present invention;

Fig. 5 is the schematic diagram of the driving assembly before the input voltage in the present invention;

Fig. 6 is the schematic diagram of driving assembly after input voltage in the present invention;

Fig. 7 is a schematic diagram of the rigid origami mechanism when the input voltages of each drive assembly are the same in the present invention;

Fig. 8 is a schematic diagram of the rigid origami mechanism when the input voltages of the driving components are not completely the same in the present invention.

Among them, 10. Rigid origami mechanism; 1. Support body; 11. First crease; 2. Rigid origami; 21. Second crease; 22. Folding plate A; 23. Folding plate B; 24. Folding plate C; 25. Folding plate D; 26. Folding plate E; 27. Folding plate F; 3. Drive assembly; 31. First rigid support member; 32. Second rigid support member; 33. Flexible base; 34. Pre-stretched Dielectric elastomer film; 35, flexible electrode; 4, pin shaft; 5, baffle plate; 6, long hole.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

It should be pointed out that the following detailed description is exemplary and is intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof. In this disclosure, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom" etc. refer to The orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only a relative term determined for the convenience of describing the structural relationship between the components or elements of the present disclosure. Public restrictions. In the present disclosure, terms such as "fixed", "connected", and "connected" should be understood in a broad sense, which means that they can be fixedly connected, integrally connected or detachably connected; they can be connected directly or through an intermediate connection. The medium is indirectly connected. For relevant researchers or technical personnel in the field, the specific meanings of the above terms in the present disclosure can be determined according to specific situations, and should not be construed as limitations on the present disclosure.

The following is a preferred embodiment for illustrating the present invention, but not intended to limit the scope of the present invention.

Embodiment one

Referring to Figures 1 to 8, as shown in the illustrations therein, a mechanical arm based on a dielectric elastomer minimum energy structure, the mechanical arm includes a plurality of rigid origami mechanisms 10 connected in series, and the rigid origami mechanisms 10 overall form Cylindrical shape, including two support bodies 1 respectively arranged at the two ends of the above-mentioned cylinder and a plurality of rigid origami 2 uniformly arranged around the center line of the above-mentioned cylinder, the connection between the above-mentioned rigid origami 2 and the above-mentioned support body 1 forms a first Creases 11, each of the above-mentioned first creases 11 is correspondingly provided with a drive assembly 3, the above-mentioned drive assembly 3 includes a dielectric elastomer driver with a minimum energy structure, and the above-mentioned drive assembly 3 has two connecting ends that can be close to or far away from each other after bending, The two connection ends of the above-mentioned driving assembly are respectively connected to form the rigid origami 2 and the support body 1 corresponding to the first crease 11, one of the connection ends of the above-mentioned driving assembly 3 is a moving end, and the moving end of the above-mentioned driving assembly 3 is connected to the supporting body 1. The distance between the corresponding first creases 11 can be changed with the bending of the above-mentioned drive assembly 3, the other connecting end of the above-mentioned drive assembly 3 is a fixed end, and the distance between the fixed end of the above-mentioned drive assembly 3 and the corresponding first crease 11 The distance between them is fixed, the above-mentioned drive assembly 3 bends to drive the angle change of the corresponding first crease 11, the angle change of the above-mentioned first crease 11 drives the deformation of the above-mentioned rigid origami 2 forming the above-mentioned first crease 11, and the above-mentioned rigid origami 2 The deformation drives the above-mentioned column to bend or change in length.

In the above technical solution, by applying a voltage to the drive components, one or more drive components are deformed, thereby deforming the rigid origami, thereby deforming the joint. The input voltage of each driving component is independently controlled. When their input voltages are the same, the joints will achieve compression movement. When the input voltages are different, the joints will achieve bending movement. When the input voltage disappears, the joints will automatically return to the initial state. On the one hand, the rigid origami and the minimum energy structural type dielectric elastomer driver are adopted, which have multiple degrees of freedom, good flexibility, fast response, greater joint load force, and strong environmental adaptability of the joint. On the other hand, due to the driving component It is set at the first crease between the rigid origami and the support body. It has good versatility and can be used to make joints of various lengths.

In one embodiment of the present invention, the drive assembly 3 further includes a first rigid support component 31 and a second rigid support component 32, the first rigid support component 31 and the second rigid support component 32 are respectively connected to the minimum energy structural formula The electroelastic actuators are respectively used as the moving end and the fixed end of the above-mentioned driving assembly 3 . By arranging a rigid driving component, the driving assembly has a certain degree of rigidity, and the manufacture and position control of the joint are easier. In other embodiments, it is also possible that: the first rigid support component and/or the second rigid support component are not provided.

In one embodiment of the present invention, when the drive component is not energized, the above-mentioned drive component 3 is in a bent state with an arched height of H1, and the angle of the first crease 11 corresponding to the above-mentioned drive component 3 is α1. When the drive component is powered on, the above-mentioned The driving assembly 3 is in a bent state or a flat state and has an arched height of H2. The angle of the first crease 11 corresponding to the driving assembly 3 is α2, H1 is greater than H2, and α1 is smaller than α2. When the drive component is not powered on, the first crease angle is about 90 degrees. At this time, the drive component is bent and can be fitted between the end face and the side of the cylinder. When the drive component is powered on, the first crease angle is an obtuse angle , at this time, the driving assembly is gradually flattened, and it can fit between the end surface and the side surface of the cylinder. In other embodiments it can also be:

In one embodiment of the present invention, the above-mentioned minimum energy structural type dielectric elastomer actuator includes a flexible substrate 33, a pre-stretched dielectric elastomer film 34 arranged on the above-mentioned flexible substrate 33, and a dielectric elastomer film 34 uniformly coated on the pre-stretched dielectric Flexible electrodes 35 on both sides of the electroelastomer film 34 .

In one embodiment of the present invention, the pre-stretched dielectric elastomer film 34 is made of polyacrylate, natural rubber or silica gel, and the flexible electrode 35 is made of carbon fat, single-wall carbon nanotube or silver nanowire conductive liquid.

In one embodiment of the present invention, the moving end of the above-mentioned driving assembly 3 is movably connected in a long hole 6 through the pin shaft 4 and the baffle plate 5, the above-mentioned pin shaft 4 passes through the above-mentioned long hole 6, and the two ends of the above-mentioned pin shaft 4 The ends are respectively connected to the above-mentioned drive assembly 3 and the above-mentioned baffle plate 5 . The long hole is simple and easy to make, and it can be formed by removing part of the material on the support body or the folding plate of the rigid origami, without setting more accessories. In other embodiments, the moving end of the driving assembly 3 may be movably connected in a limiting slot through a T-shaped pin, or the moving end of the driving assembly may be movably connected to a guide rod through a sliding sleeve.

In one embodiment of the present invention, the moving direction of the moving end of the driving assembly 3 is perpendicular to the corresponding first crease 11 . The moving direction of the moving end of the driving component is perpendicular to the first crease, and the deformation of the joint is smoother. In other embodiments, the moving direction of the moving end of the driving assembly and the first crease may also form an acute angle or an obtuse angle, as long as the moving end of the driving assembly can be moved.

In one embodiment of the present invention, the fixed end of the above-mentioned driving assembly 3 is bonded and fixed. The fixed end of the driving component is fixed by bonding, which will not cause damage to the support body or the rigid origami, and is easy to operate. In other embodiments, it may also be that: the fixed end of the driving assembly is fixed by a bolt or by a buckle structure.

In an embodiment of the present invention, the moving end of the driving assembly 3 is connected to the rigid origami 2 , and the fixed end of the driving assembly 3 is connected to the support body 1 . Since the length of the cylinder is generally greater than its diameter, the size of the rigid origami is more suitable for the connection of the moving end of the drive assembly than the size of the bracket body, and can provide space for the movement of the moving end of the drive assembly. In other embodiments, it may also be that: the moving end of the above-mentioned driving assembly is connected to the above-mentioned support body, and the fixed end of the above-mentioned driving assembly is connected to the above-mentioned rigid origami.

In one embodiment of the present invention, the above-mentioned rigid origami 2 is provided with a second crease 21, and the above-mentioned second crease 21 is a single-vertex multi-crease pattern, and each of the above-mentioned rigid origami 2 and the above-mentioned two support bodies 1 constitute a Closed space four-linkage. Each rigid origami and two brackets form a non-closed four-linkage, and the driving component has a certain degree of rigidity, which makes it easier to make joints and position control. The above-mentioned single-vertex multi-crease pattern is the crease pattern of the umbrella surface. The second crease 21 is specifically a single-vertex six-crease pattern. The above-mentioned rigid origami 2 includes folding plates A22, B23, C24, D25, E26 and F27 which are sequentially connected around the apex by rotating shafts, and the center lines of each rotating shaft pass through the apex position. The folding plate A22 and the folding plate D25 are respectively connected to the two support bodies 1 .

In a preferred implementation mode in the embodiment of the present invention, the above-mentioned support body 1 is a hexagonal thin plate, and the above-mentioned hexagonal thin plate includes alternately arranged first sides and second sides, and the three first sides are driven by driving The assembly is connected to the rigid origami, and the three above-mentioned second sides are not arranged.

In a preferred implementation of the embodiments of the present invention, the above-mentioned support body and the above-mentioned rigid origami are manufactured by 3D printing or laser cutting, and the first crease 11 of the above-mentioned joint is connected by a flexible material. The flexible base, the first and second rigid support parts are also made by 3D printing or laser cutting, and the second crease is also connected by flexible material. In addition, there are many ways to make pin shafts and baffles, and plastic or metal materials can be used.

In actual use, the above-mentioned joint is connected between two objects, and the two bracket bodies are respectively connected with the two objects. When the same voltage is applied to all driving components, the joint shortens. When voltage is applied to some driving components, the joint shortens. bending.

The foregoing is a description of the embodiments of the present invention, and through the above descriptions of the disclosed embodiments, those skilled in the art can implement or use the present invention. Various modifications to the embodiments of the invention will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

A mechanical arm based on a dielectric elastomer minimum energy structure, the mechanical arm includes a plurality of rigid origami mechanisms connected in series, and the rigid origami mechanism is in the shape of a cylinder as a whole, including Two support bodies and a plurality of rigid origami uniformly arranged around the center line of the cylinder, the connection between the rigid origami and the support forms a first crease, and each of the first folds Corresponding to the traces, a drive assembly is provided, and the drive assembly includes a dielectric elastomer driver with a minimum energy structure. The drive assembly has two connection ends that can approach or move away from each other after being bent, and the two connection ends of the drive assembly are respectively connected to form The rigid origami and support body corresponding to the first crease, one of the connecting ends of the driving assembly is a moving end, and the distance between the moving end of the driving assembly and the corresponding first crease can be adjusted with the drive The other connecting end of the drive component is a fixed end, and the distance between the fixed end of the drive component and its corresponding first crease is fixed, and the bending of the drive component drives its corresponding first crease. A change of the crease angle, the change of the angle of the first crease drives the deformation of the rigid origami forming the first crease, and the deformation of the rigid origami drives the bending or the change of the length of the cylinder.
The mechanical arm based on a dielectric elastomer minimum energy structure according to claim 1, wherein the drive assembly further comprises a first rigid support component and a second rigid support component, and the first rigid support component and the The second rigid support components are respectively connected to the minimum energy structure type dielectric elastomer driver and serve as the moving end and the fixed end of the driving assembly respectively.
The mechanical arm based on the minimum energy structure of a dielectric elastomer according to claim 1, wherein when the drive component is not powered, the drive component is in a bent state and the arch height is H1, and the drive component corresponds to the first A crease angle is α1, when the drive component is energized, the drive component is in a bent state or a flat state and the arch height is H2, the corresponding first crease angle of the drive component is α2, H1 is greater than H2, and α1 is smaller than α2 .
The mechanical arm based on the dielectric elastomer minimum energy structure according to claim 1, wherein the minimum energy structure dielectric elastomer driver comprises a flexible base, a pre-stretched dielectric on the flexible base An electric elastomer film and flexible electrodes uniformly coated on both sides of the pre-stretched dielectric elastomer film.
The mechanical arm based on a dielectric elastomer minimum energy structure according to claim 4, wherein the pre-stretched dielectric elastomer film is made of polyacrylate, natural rubber or silica gel, and the flexible electrode is made of carbon grease, single-walled carbon nanotubes, or silver nanowires.
The mechanical arm based on a dielectric elastomer minimum energy structure according to claim 1, wherein the moving end of the driving assembly is movably connected in a long hole through a pin shaft and a baffle plate, and the pin shaft passes through Through the long hole, the two ends of the pin shaft are respectively connected to the driving assembly and the baffle plate.
The mechanical arm based on a dielectric elastomer minimum energy structure according to claim 6, wherein the moving direction of the moving end of the driving component is perpendicular to the corresponding first crease.
The mechanical arm based on a dielectric elastomer minimum energy structure according to claim 1, wherein the fixed end of the driving assembly is fixed by bonding.
The mechanical arm based on a dielectric elastomer minimum energy structure according to claim 1, wherein the moving end of the driving assembly is connected to the rigid origami, and the fixed end of the driving assembly is connected to the support body.
The mechanical arm based on the minimum energy structure of a dielectric elastomer according to claim 1, wherein only one second crease is provided on the rigid origami, and the second crease is a single-vertex multi-crease pattern .