CN114367966A - Robotic Arm Based on Minimum Energy Structure of Dielectric Elastomer - Google Patents

Abstract

The invention discloses a mechanical arm based on a minimum energy structure of a dielectric elastomer. The mechanical arm includes a plurality of rigid origami mechanisms connected in series. The rigid origami mechanism is in the shape of a cylinder as a whole, and includes two bracket bodies and a plurality of rigid origami mechanisms. , a first crease is formed at the connection between the rigid origami and the bracket body, and each first crease is correspondingly provided with a driving component, the driving component includes a minimum-energy structural dielectric elastomer driver, and the driving component has two parts that can approach or move away from each other after bending. There are two connecting ends, one of the connecting ends of the driving component is the moving end, the distance between the moving end of the driving component and the corresponding first crease can be changed with the bending of the driving component, and the other connecting end of the driving component is The fixed end, the distance between the fixed end of the driving component and its corresponding first crease is fixedly set. The invention has multiple degrees of freedom, good flexibility, fast response speed, larger driving force and strong environmental adaptability.

Description

Robotic Arm Based on Minimum Energy Structure of Dielectric Elastomer

technical field

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

Background technique

Most of the existing robotic arms are made of rigid materials and are driven by motors or hydraulics, which can output large loads and replace humans in some extreme environments. However, the immutability of rigid materials limits the environmental adaptation of robotic arms. Therefore, a new type of flexible manipulator with the ability to adapt to complex environments is urgently needed. Dielectric elastomer materials have the characteristics of large driving strain, high energy density, high energy conversion efficiency, and fast response speed, and are more suitable for driving flexible robotic arms. In addition, in recent years, origami structures have attracted wide attention due to their good folding characteristics and large folding aspect ratios. 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 aviation manipulator based on a shape memory polymer and a dielectric elastomer and a manufacturing method thereof. The mechanical arm of the invention does not depend on a complex mechanical structure, and its deployment mainly depends on the shape memory effect of the shape memory polymer and the self-stretching property of the dielectric elastomer under voltage. The density is small and can withstand large deformation. It is compressed and stored before the launch to reduce the space and payload occupied during launch. The stretching of the above-mentioned robotic arms is driven by a mixture of shape memory polymers and dielectric elastomers, and it is difficult to precisely control the stretching amount and the driving force is small.

Referring to the paper "Soft pneumatic actuator-driven origami-inspired modular robotic "pneumagami".", the paper introduces a new modular robot for realizing reconfigurable, actively controlled, high degree of freedom (DOF) with a compact form factor ) system, 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 complex structure.

The Chinese invention patent publication (announcement) No. CN112959346A discloses a rigid origami-type dexterous hand modular driving knuckle driven by a dielectric elastomer. The knuckle 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 knuckle, and the dielectric elastomer material itself inherently The flexibility of combined with the folding properties of the origami structure improves the environmental adaptability of the knuckles. The above-mentioned knuckles have the following disadvantages: ①The driving force is small; ②The bending angle of the knuckles is difficult to control; ③When the knuckles are compressed or bent, the deformation of the two connected origami units is difficult to predict, and may interfere with the driver to destroy the fingers. ④ When the length of the knuckle changes, the multi-layer curved dielectric elastomer actuator also needs to be designed longer, and the versatility is poor.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies in the prior art, the present invention provides a mechanical arm based on the minimum energy structure of a dielectric elastomer 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 the minimum energy structure of a dielectric elastomer, 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 bracket bodies arranged at both ends of the cylinder and a plurality of rigid origami evenly distributed around the center line of the cylinder, the connection between the rigid origami and the bracket body forms a first crease, and each The first fold is correspondingly provided with a drive assembly, the drive assembly includes a minimum energy structural dielectric elastomer driver, the drive assembly has two connection ends that can approach or move away from each other after bending, and the two connections of the drive assembly The ends are respectively connected to the rigid origami forming the corresponding first crease and the bracket body, 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 adjusted. The other connecting end of the drive assembly is a fixed end, and the distance between the fixed end of the drive assembly and its corresponding first crease is fixed, and the drive assembly bends to drive The corresponding first crease angle changes, the first crease angle change drives the rigid origami forming the first crease to deform, and the rigid origami deformation drives the cylinder to bend or change its length.

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

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

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

In an 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 drive assembly is movably connected to a long hole through a pin shaft and a baffle plate, the pin shaft passes through the long hole, and both ends of the pin shaft are connected respectively the drive assembly and the baffle.

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

In an embodiment of the present invention, the fixed end of the driving assembly is fixed by bonding.

In one embodiment of the present invention, the moving end of the driving component is connected to the rigid origami, and the fixed end of the driving component is connected to the bracket body.

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

Due to the application 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 the minimum energy structure type dielectric elastomer driver, which has multiple degrees of freedom, good flexibility, fast response speed, greater driving force, Strong adaptability to the environment;

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

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

Description of drawings

The accompanying drawings that form 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 improper limitations on the present application.

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

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

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;

4 is a schematic diagram of a drive assembly in the present invention;

Fig. 5 is the schematic diagram of the drive assembly before inputting the voltage in the present invention;

6 is a schematic diagram of a drive assembly after inputting a voltage in the present invention;

7 is a schematic diagram of a 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 folding mechanism when the input voltages of the driving components are not identical in the present invention.

Among them, 10, rigid origami mechanism; 1, bracket body; 11, first crease; 2, rigid origami; 21, second crease; 22, folding board A; 23, folding board B; 24, folding board 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; Dielectric elastomer film; 35, flexible electrode; 4, pin; 5, baffle; 6, long hole.

Detailed ways

The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the application. Unless otherwise defined, 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 herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, devices, components and/or combinations thereof. In this disclosure, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", etc. The orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only a relational word determined for the convenience of describing the structural relationship of each component or element of the present disclosure, and does not specifically refer to any component or element in the present disclosure, and should not be construed as a reference to the present disclosure. public restrictions. In the present disclosure, terms such as "fixed connection", "connected", "connected", etc. should be understood in a broad sense, indicating that it may be a fixed connection, an integral connection or a detachable connection; it may be directly connected, or through an intermediate connection. media are indirectly connected. For the relevant scientific research or technical personnel in the field, the specific meanings of the above terms in the present disclosure can be determined according to specific circumstances, and should not be construed as limitations on the present disclosure.

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

Example 1

Referring to FIGS. 1 to 8 , as shown in the legends therein, a mechanical arm based on the minimum energy structure of a dielectric elastomer, the above-mentioned mechanical arm includes a plurality of rigid origami mechanisms 10 connected in series, and the above-mentioned rigid origami mechanisms 10 are shown as a whole. The shape of the cylinder includes two brackets 1 respectively arranged at both ends of the cylinder and a plurality of rigid origami 2 evenly distributed around the centerline of the cylinder. The connection between the rigid origami 2 and the bracket 1 forms a first The folds 11, each of the first folds 11 is correspondingly provided with a drive assembly 3, the drive assembly 3 includes a minimum energy structural dielectric elastomer driver, and the drive assembly 3 has two connection ends that can approach or move away from each other after being bent, The two connecting ends of the above-mentioned driving assembly are respectively connected to the rigid origami 2 and the bracket body 1 that form the corresponding first crease 11. One of the connecting ends of the above-mentioned driving assembly 3 is the 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 folds 11 can be changed with the bending of the above-mentioned driving component 3. The other connecting end of the above-mentioned driving component 3 is a fixed end, and the fixed end of the above-mentioned driving component 3 and the corresponding first fold 11 are separated. The distance between the above-mentioned driving components 3 is bent to change the angle of the corresponding first crease 11, and 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, the above-mentioned rigid origami 2 The deformation drives the above-mentioned cylinder to bend or change its length.

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

In an embodiment of the present invention, the above-mentioned driving assembly 3 further includes a first rigid supporting member 31 and a second rigid supporting member 32, and the above-mentioned first rigid supporting member 31 and the above-mentioned second rigid supporting member 32 are respectively connected to the above-mentioned minimum energy structural medium. The electro-elastic body drives are respectively used as the moving end and the fixed end of the above-mentioned drive assembly 3 . By arranging the rigid driving components, the driving components are provided with a certain rigidity, and the manufacture and position control of the joints are easier. In other embodiments, the above-mentioned first rigid support member and/or second rigid support member may not be provided.

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

In one embodiment of the present invention, the above-mentioned minimum energy structure-type dielectric elastomer driver includes a flexible substrate 33, a pre-stretched dielectric elastomer film 34 disposed 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 electro-elastomeric membrane 34 .

In an 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 grease, single-walled carbon nanotube or silver nanowire conductive liquid.

In an embodiment of the present invention, the moving end of the above-mentioned driving assembly 3 is movably connected to a long hole 6 through a pin shaft 4 and a baffle 5, the above-mentioned pin shaft 4 passes through the above-mentioned long hole 6, and two parts of the above-mentioned pin shaft 4 pass through the above-mentioned long hole 6. 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. It only needs to remove part of the material on the bracket body or the folding board of the rigid origami to form, and there is no need to set more accessories. In other embodiments, the moving end of the driving assembly 3 may be movably connected to a limiting groove 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 an 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 joint is deformed more smoothly. 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 an 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 bracket body or the rigid origami, and is easy to operate. In other embodiments, the fixed end of the above-mentioned driving assembly may be fixed by bolts or by a snap structure.

In an embodiment of the present invention, the movable end of the above-mentioned driving assembly 3 is connected to the above-mentioned rigid origami 2 , and the fixed end of the above-mentioned driving assembly 3 is connected to the above-mentioned bracket body 1 . Since the length of the column 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, which can provide space for the moving end of the drive assembly to move. In other embodiments, the movable end of the drive assembly may be connected to the bracket body, and the fixed end of the drive assembly may be connected to the rigid origami.

In one embodiment of the present invention, the rigid origami 2 is provided with a second crease 21 , the second crease 21 is a single-vertex multi-fold pattern, and each of the rigid origami 2 and the two brackets 1 constitute a non- Closed space four-bar linkage. Each rigid origami and two bracket bodies form a non-closed four-link, and the drive assembly has a certain rigidity, which makes the manufacture and position control of the joint easier. The above-mentioned single vertex multi-crease pattern is the fold pattern of the umbrella surface. The second crease 21 is specifically a single vertex six crease pattern. The above-mentioned rigid origami 2 includes a folding plate A22, a folding plate B23, a folding plate C24, a folding plate D25, a folding plate E26 and a folding plate F27 connected by a rotating shaft in sequence around the apex. The centerline of each rotating shaft passes through the apex position. The folding plate A22 and the folding plate D25 connect the two bracket bodies 1 respectively.

In a preferred implementation in the embodiments of the present invention, the above-mentioned bracket 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 with rigid origami, and the three above-mentioned second sides are not arranged.

In a preferred embodiment of the embodiments of the present invention, the above-mentioned bracket 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 substrate, the first and second rigid support members are also made by 3D printing or laser cutting, and the second fold is also connected using flexible materials. In addition, there are many ways to make pins and baffles, and either plastic or metal materials can be used.

In actual use, the above joints are 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 joints shorten, and when voltage is applied to some of the driving components, the joints are shortened. bending.

The above is a description of the embodiments of the present invention. The above description of the disclosed embodiments enables those skilled in the art to realize 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 generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to 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 (10)

1. A mechanical arm based on a dielectric elastomer minimum energy structure, the mechanical arm comprises a plurality of rigid origami mechanisms connected in series, the rigid origami mechanisms are in the shape of a cylinder as a whole, including Two bracket bodies at both ends and a plurality of rigid origami evenly distributed around the center line of the cylinder, the connection between the rigid origami and the bracket body forms a first crease, characterized in that each of the first folds is formed. A driving component is arranged corresponding to a crease, and the driving component includes a minimum-energy structure-type dielectric elastomer driver. The driving component has two connecting ends that can approach or move away from each other after being bent, and the two connecting ends of the driving component are respectively The rigid origami forming the corresponding first crease is connected to the bracket body, 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 adjusted according to any requirement. The other connecting end of the driving component is a fixed end, and the distance between the fixed end of the driving component and its corresponding first crease is fixed, and the bending of the driving component drives the fixed end of the driving component. Corresponding to the change of the first crease angle, the change of the first crease angle drives the rigid origami forming the first crease to deform, and the rigid origami deformation drives the cylinder to bend or change the length. 2 . The mechanical arm based on the dielectric elastomer minimum energy structure according to claim 1 , wherein the driving assembly further comprises a first rigid support part and a second rigid support part, the first rigid support part and the second rigid supporting member 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. 3 . The manipulator based on the minimum energy structure of dielectric elastomer according to claim 1 , wherein when the drive assembly is not powered on, the drive assembly is in a bent state and the arch height is H1 , and the drive assembly corresponds to 3 . The first crease angle is α1. When the drive assembly is energized, the drive assembly is in a bent or flat state and the height of the arch is H2. The corresponding first crease angle of the drive assembly is α2. H1 is greater than H2, and α1 less than α2. 4 . The mechanical arm based on a dielectric elastomer minimum energy structure according to claim 1 , wherein the minimum energy structure-type dielectric elastomer driver comprises a flexible substrate and a pre-stretching device provided on the flexible substrate. 5 . The dielectric elastomer film and the flexible electrodes uniformly coated on both sides of the pre-stretched dielectric elastomer film. 5 . The mechanical arm based on the minimum energy structure of dielectric elastomer 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 5 . Use carbon grease, single-wall carbon nanotubes or silver nanowire conductive liquid. 6 . The mechanical arm based on the minimum energy structure of dielectric elastomer according to claim 1 , wherein the moving end of the driving component is movably connected to a long hole through a pin shaft and a baffle, and the pin A shaft passes through the long hole, and two ends of the pin shaft are respectively connected to the driving assembly and the baffle. 7 . The mechanical arm based on the 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. 8 . 8 . The mechanical arm based on a dielectric elastomer minimum energy structure according to claim 1 , wherein the fixed end of the driving component is fixed by bonding. 9 . 9 . The mechanical arm based on a dielectric elastomer minimum energy structure according to claim 1 , wherein the moving end of the driving component is connected to the rigid origami, and the fixed end of the driving component is connected to the bracket body. 10 . . 10 . The mechanical arm based on the minimum energy structure of dielectric elastomer according to claim 1 , wherein the rigid origami is provided with only one second crease, and the second crease is multi-fold on a single vertex. 11 . trace pattern.

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