An adjustable fluid-driven artificial muscle based on origami spring and working method

Abstract

The application relates to a controllable fluid-driven artificial muscle based on a paper-folding spring and a working method, which comprises a fluid chamber, an elastic element and a flexible wire; the fluid chamber is folded, the flexible wire penetrates the inside of the fluid chamber, and the elastic element is nested between the folding lines of the folded fluid chamber and used for limiting the mutual movement between the folding lines of the fluid chamber. The fluid chamber is connected to an external pressure source, after the external pressure source inputs pressurized fluid into the fluid chamber, the fluid chamber locally expands and deforms, the whole produces elongation and torsion, and the elastic element produces elongation; after the external pressure source is closed, the fluid chamber gradually shrinks and twists, returns to the initial length and angle, and drives the elastic element to shrink and return to the initial length. The fluid-driven soft driver based on the paper-folding spring has the advantages of simple structure, adjustable rigidity and chirality, can produce a large deformation rate through external pressure source driving, and has wide application prospects.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of soft robots, and particularly relates to a controllable fluid-driven artificial muscle based on a paper-folding spring and a working method. BACKGROUND

[0002] Traditional robots are composed of rigid elements, are mature in technology and are widely applied, but have problems such as complex structure, high cost, poor flexibility and poor environmental adaptability. With the increasing demand for human-computer interaction, soft robots have gradually emerged. Soft robots are made of soft materials, and the driver components are similar to biological muscles, and have flexibility, safety and environmental adaptability, thus becoming a new development direction. The fluid-driven artificial muscle is a new type of artificial muscle technology that utilizes the pressure difference between fluid and environment for driving. The most classic fluid artificial muscle is the Mckibben artificial muscle, which has a relatively simple structure but small deformation; the subsequently emerged bellows type artificial muscle can increase the deformation by using low modulus silica gel material, but the deformation is single. Therefore, it is of great significance to develop a fluid-driven artificial muscle with simple structure, large deformation, and adjustable chirality and stiffness. SUMMARY

[0003] The application aims to overcome the deficiencies of the prior art, and provides a controllable fluid-driven artificial muscle based on a paper-folding spring and a working method, which can maintain stable operation of a power grid, quickly and accurately provide an optimal load transfer scheme, greatly improve the work efficiency of dispatchers and guarantee the safe and stable operation of the power grid.

[0004] The application solves the technical problems by adopting the following technical scheme:

[0005] A controllable fluid-driven artificial muscle based on a paper-folding spring, comprising a fluid chamber, an elastic element and a flexible wire, wherein the fluid chamber is folded, the flexible wire penetrates the inside of the fluid chamber, and the elastic element is nested between the fold lines of the folded fluid chamber and used for limiting the mutual movement between the fold lines of the fluid chamber.

[0006] Moreover, the fluid chamber is obtained according to a folding spring folding method, and the elastic element is nested on the adjacent fold lines on one side of the folded fluid chamber.

[0007] The fluid chamber is stacked by two layers of films, and the long edges of the films are sealed to obtain the fluid chamber.

[0008] Moreover, the fluid chamber is folded through a plurality of different folding sequences, so that the artificial muscle produces torsional deformation in different directions after being filled with fluid, and the control of the chirality is realized.

[0009] A working method of a controllable fluid-driven artificial muscle based on a paper-folding spring, comprising the following steps:

[0010] Step 1, the fluid chamber is connected to an external pressure source;

[0011] Step 2, after the external pressure source supplies pressurized fluid to the fluid chamber, the fluid chamber locally expands and deforms, and the whole produces elongation and torsion;

[0012] Step 3, after the external pressure source is closed, the fluid chamber gradually shrinks and twists to return to the initial length and angle, driving the elastic element to shrink to the initial length.

[0013] The advantages and positive effects of the present application are:

[0014] The present application comprises a fluid chamber, an elastic element and a flexible wire; wherein the fluid chamber is folded, the flexible wire penetrates the inside of the fluid chamber, and the elastic element is nested between the fold lines of the folded fluid chamber, for limiting the mutual movement between the fold lines of the fluid chamber. The fluid chamber is connected to an external pressure source, and after the external pressure source supplies pressurized fluid to the fluid chamber, the fluid chamber locally expands and deforms, and the whole produces elongation and torsion, and the elastic element produces elongation; after the external pressure source is closed, the fluid chamber gradually shrinks and twists to return to the initial length and angle, driving the elastic element to shrink to the initial length. The fluid-driven soft actuator based on the origami spring of the present application has simple structure, adjustable stiffness and chirality, can produce a large deformation rate through external pressure source driving, and has broad application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The material used for the artificial muscle of the present application;

[0016] Figure 2 The schematic diagram of the manufacturing method of the fluid chamber;

[0017] Figure 3 The schematic diagram of the specific manufacturing method of the artificial muscle of the present application;

[0018] Figure 4 The overall schematic diagram of the artificial muscle of the present application;

[0019] Figure 5 The deformation schematic diagram of the artificial muscle of the present application;

[0020] Figure 6 The deformation rate data diagram of the artificial muscle of the present application.

[0021] Label explanation:

[0022] 1-film, 2-elastic element, 3-flexible wire. DETAILED DESCRIPTION

[0023] The present application will be further described in detail below in combination with the drawings.

[0024] A type of adjustable fluid-driven artificial muscle based on origami springs, such as Figure 1 and Figure 2 As shown, it includes a fluid chamber 4, an elastic element 2, and a flexible line 3. The fluid chamber is folded, and the flexible line runs through the fluid chamber, supporting the flow channel and increasing its cross-sectional area. The elastic element is nested between the folded lines of the fluid chamber to restrict the relative movement between them. The fluid chamber is obtained using a folding spring method, and the elastic element is nested on adjacent folded lines on one side of the folded fluid chamber.

[0025] The fluid chamber is formed by stacking two thin films 1 and sealing the long side of the films.

[0026] like Figure 3 As shown, based on the origami spring method, the fluid chamber is folded sequentially to form a self-locking folded structure. During the folding process, elastic elements are nested sequentially at the fold lines of the fluid chamber. The final artificial muscle structure is as follows. Figure 4 As shown.

[0027] Meanwhile, the fluid chambers can be designed with multiple folding sequences, allowing the artificial muscle to undergo torsional deformation in different directions after being filled with fluid, thereby achieving chiral control. Specifically, by changing the folding sequence of the fluid chambers, two different chiral deformations can be produced: left-handed deformation and right-handed deformation.

[0028] The elastic element of this invention can adjust the stiffness of the overall artificial muscle according to the different material modulus and size.

[0029] The control mechanism of this invention includes: stiffness factor and chiral factor.

[0030] The stiffness factor is as follows: Under driving conditions, the magnitude of elongation deformation is characterized by elongation rate and rotation angle. The greater the stiffness of the elastic element, the smaller the overall deformation of the artificial muscle. The number of elastic units nested in the folded fluid chamber, as well as their material and geometric parameters, can be controlled. Increasing the number of elastic elements, improving the elastic modulus of the elastic element material, and increasing the cross-sectional area of ​​the elastic element can all increase the stiffness of the elastic element, and vice versa. Increasing the stiffness of the elastic unit will reduce the amount of deformation of the artificial muscle under the same driving conditions (fluid pressure), and vice versa.

[0031] The chiral factor is: when the fluid chamber is folded, such as... Figure 5As shown, when the folding sequence is lower left upper right, i.e. "left-handed folding sequence", the internal pressure generated by the fluid entering the chamber will push the fluid chamber origami structure to expand and deform in the left-handed direction when twisted. Such left-handed deformation makes the artificial muscle twist in the counterclockwise direction during expansion, thus being suitable for driving systems with left-handed motion requirements; when the folding sequence is upper left lower right, i.e. "right-handed folding sequence", the fluid pressure inside the fluid chamber will make the structure deform in the right-handed direction. Such right-handed deformation means that the artificial muscle will twist in the clockwise direction during expansion, which can meet the right-handed twisting requirements.

[0032] A working method of a controllable fluid-driven artificial muscle based on a paper-folding spring, as shown in Figure 5

[0033] The artificial muscle is connected to an external pressure source, the internal pressure of the fluid chamber is increased, at this time the fluid chamber is inflated, the elastic element is stretched, the area of the fluid chamber in contact with each other is extruded, and the overall structure is affected by the asymmetric boundary conditions of folding and elongation, and also produces a twisting motion; after cutting off the pressure source, the internal pressure of the fluid chamber is reduced, and returns to the initial length, at the same time the elastic element returns to the initial length, and the artificial muscle returns to the initial state. As shown in Figure 6 As shown, the maximum deformation rate of the artificial muscle of the present application can reach more than 6.5, wherein F refers to the width of the fluid chamber, and R refers to the width of the elastic element.

[0034] It should be emphasized that the embodiments described in the present application are illustrative rather than limiting, and therefore the present application includes and is not limited to the embodiments described in the specific embodiments, and any other embodiments derived by those skilled in the art according to the technical solutions of the present application also belong to the scope of protection of the present application.​

Claims

1. A working method of a controllable fluid-driven artificial muscle based on a paper-folding spring, characterized in that: The controllable fluid-driven artificial muscle comprises a fluid chamber, an elastic element and a flexible wire, wherein the fluid chamber is folded, the flexible wire is threaded inside the fluid chamber, and the elastic element is nested between the folding lines of the folded fluid chamber to limit the mutual movement between the folding lines of the fluid chamber. The fluid chamber is folded according to a paper-folding spring folding method, and the elastic element is nested on the adjacent folding lines on one side of the folded fluid chamber. The fluid chamber is stacked by two layers of film, and the long edges of the film are sealed to obtain the fluid chamber. The fluid chamber is folded by different folding sequences, so that the artificial muscle produces torsional deformation in different directions after being filled with fluid, and the control similar to chirality is realized. The elastic element controls the stiffness of the overall artificial muscle according to the modulus of elasticity, size, etc. The control mechanism includes stiffness factor and chirality factor. The stiffness factor is that in the driving state, the elongation deformation size is characterized by elongation rate and rotation angle, the greater the stiffness of the elastic element, the smaller the overall deformation of the artificial muscle, and the number of elastic elements nested in each unit of the folded fluid chamber, the material and geometric parameters are controlled, increasing the number of elastic elements, increasing the elastic modulus of the elastic element material, and increasing the cross-sectional area of the elastic element can increase the stiffness of the elastic element, and vice versa, the increase of the stiffness of the elastic element will reduce the deformation of the artificial muscle under the same driving state, and vice versa. The chirality factor is that when folding the fluid chamber, when the folding sequence is down left up right, the internal pressure generated by the fluid entering the chamber will push the paper structure of the fluid chamber to unfold and deform in the left rotation direction when twisting, such left rotation deformation makes the artificial muscle twist in the counterclockwise direction during expansion, thereby being suitable for the driving system of left rotation motion demand; when the folding sequence is up left down right, the fluid pressure in the fluid chamber will make the structure deform in the right rotation direction, and such right rotation deformation means that the artificial muscle will twist in the clockwise direction during expansion, which meets the right rotation demand. The working method of the controllable fluid-driven artificial muscle based on the paper-folding spring comprises the following steps: Step 1, connecting the fluid chamber to an external pressure source; Step 2, after the external pressure source introduces pressurized fluid into the fluid chamber, the fluid chamber locally deforms, and the whole produces elongation and torsion; Step 3, after the external pressure source is closed, the fluid chamber gradually shrinks and twists, and returns to the initial length and angle, driving the elastic element to shrink and return to the initial length.

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