Uniradial constraint type pneumatic soft driver with embedded fiber ring

Abstract

The invention discloses an embedded fiber ring single radial constraint type pneumatic soft body driver, and relates to the technical field of pneumatic soft body robots, the embedded fiber ring single radial constraint type pneumatic soft body driver comprises three drivers, each driver comprises an elastic layer and a filter joint, the filter joints are embedded in the elastic layers, the elastic layers are arranged to be of a cylindrical structure, and the filter joints are arranged on the elastic layers. The elastic layer is filled with hard interference ball particles, a plurality of fiber rings are embedded in the side wall of the elastic layer in a surrounding mode, and the multiple fiber rings are arranged in an array mode in the axial direction of the driver. The single radial constraint type pneumatic soft driver with the embedded fiber ring has the characteristics of positive pressure axial extension and negative pressure rigidity enhancement, the three drivers are bonded and combined in parallel by utilizing a secondary casting process, and the functions of rigidity enhancement and multidirectional bending can be simultaneously realized through the positive and negative air pressure driving combination of each driver.

Description

Technical Field

[0001] The present invention relates to the technical field of pneumatic soft robots, and more particularly to a single-radial constrained pneumatic soft actuator with an embedded fiber ring. Background Art

[0002] Pneumatic soft robots have excellent compliance and environmental adaptability, and have broad application prospects in the fields of medical devices, geological exploration, disaster rescue, and flexible grasping. As the main moving component of pneumatic soft robots, the performance of pneumatic soft actuators directly affects the working effect of soft robots. Due to their inherent low-rigidity characteristics, existing pneumatic soft actuators are difficult to meet the requirements of high-load tasks. The particle-interference soft actuator enhances stiffness by adding hard particles inside the cavity. Under vacuum drive, the particles are pressed against the inner wall of the cavity, and the interaction force between the particles increases. However, in the prior art, the working mode of the particle-interference soft actuator is single, and it can only achieve a single stretching or bending function; during the deformation process under positive pressure drive, the particles are prone to recombination, resulting in uncertain structure and shape of the actuator, affecting its shape retention ability and motion accuracy; the external winding fiber constraint structure is likely to cause damage to the surface of the actuator, affecting the service life and reliability of the actuator. Summary of the Invention

[0003] The purpose of the present invention is to provide a single-radial constrained pneumatic soft actuator with an embedded fiber ring, which improves the load-bearing capacity of the soft actuator, enhances the shape retention ability of the particle-interference soft actuator, and realizes the positive and negative pressure dual-drive mode of the particle-interference soft actuator.

[0004] To achieve the above purpose, the present invention provides a single-radial constrained pneumatic soft actuator with an embedded fiber ring, including actuators. There are three actuators, and each of the three actuators includes an elastic layer and a filter joint. The filter joint is embedded in the elastic layer. The elastic layer is arranged in a cylindrical structure. The inside of the elastic layer is filled with hard interference ball particles. A fiber ring is embedded around the side wall of the elastic layer. There are multiple fiber rings, and the multiple fiber rings are arranged in an array along the axial direction of the actuator.

[0005] Preferably, the fiber ring is formed by binding both ends of a textile thread into a ring structure. The fiber ring is arranged in a circular cross-section ring structure. The fiber ring uses a textile material with axial tensile but non-compressive characteristics.

[0006] Preferably, the lower bottom layer of the elastic layer is closed, and the upper bottom layer is provided with a cylindrical air duct. The cylindrical air duct is designed with increased thickness. The cylindrical air duct is connected to the filter joint.

[0007] Preferably, a double-toothed cloud shoulder is provided on the side of the filter joint. A connecting pipe is provided between the double-toothed cloud shoulder and the cylindrical air duct. The double-toothed cloud shoulder is connected to the pipe. A flange plate shoulder is provided at the lower end of the filter joint. Through holes are provided on the flange plate shoulder, and the through holes are cast together with the elastic layer.

[0008] Preferably, an equilateral triangular air inlet duct is provided inside the filter joint, and the inscribed circle of the cross-section of the equilateral triangular air inlet duct is smaller than the diameter of the hard interference ball particles.

[0009] Preferably, the diameter of the hard interference ball particles is determined by the unit spacing of the fiber ring, and the diameter of the hard interference ball particles is not unique.

[0010] Preferably, the three drivers are adhesively combined side by side through secondary casting, and the stiffness enhancement and multi-directional bending are simultaneously achieved through the positive and negative air pressure combination of the three drivers.

[0011] Therefore, the present invention adopts the above-mentioned single-radial constraint pneumatic soft actuator with an embedded fiber ring to realize the positive and negative pressure dual-drive characteristics of the particle interference soft actuator. Since the fiber ring is embedded inside the side wall of the elastic layer, when positive pressure is introduced into the cavity of the soft actuator, the radial expansion of the side wall of the elastic layer of the actuator is restricted. At this time, the internal filling ball particles can only flow along the axis direction of the actuator under the action of gravity, effectively avoiding the problem of random multi-directional recombination of particles, enhancing the shape retention ability of the particle interference soft actuator. At the same time, the deformation of the actuator in the axial direction is not restricted, and the fiber ring can move axially with the elastic layer. Therefore, the actuator can realize axial elongation under positive pressure. When driven by negative pressure, under the action of atmospheric pressure, the fiber ring retracts with the inner wall of the elastic layer, squeezing the hard interference ball particles, increasing the mutual force between the hard interference ball particles, and enhancing the stiffness of the actuator. Through the side-by-side combination of three drivers and the use of different air pressure combinations, multi-directional bending can be achieved, thus solving the problems of single movement direction and complex combination method of pneumatic soft actuators in the prior art.

[0012] The following will further describe the technical solutions of the present invention in detail through the drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of an embodiment of a single-radial constraint pneumatic soft actuator with an embedded fiber ring of the present invention; Figure 2 is a cross-sectional view of the actuator of the present invention; Figure 3 is a schematic structural diagram of the filter joint of the present invention; Figure 4 is a top view of the filter joint of the present invention; Figure 5 is a schematic structural diagram of the fiber ring of the present invention; Figure 6 This is the simulation diagram of the single-chamber positive-pressure drive deformation of the parallel driver of the present invention; Reference numerals 1. Elastic layer; 1-1. Upper bottom layer; 1-2. Side wall of elastic layer; 1-3. Lower bottom layer; 2. Filter joint; 2-1. Double-tooth shoulder; 2-2. Flange shoulder; 2-3. Equilateral triangle air inlet; 3. Hard interference ball particles; 4. Fiber ring. Detailed implementation manners

[0014] The technical solutions of the present invention will be further described below with reference to the drawings and embodiments.

[0015] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the field to which the present invention belongs. The "first", "second" and similar terms used in the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "comprising" or "including" mean that the elements or objects appearing before this term cover the elements or objects listed after this term and their equivalents, without excluding other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left", "right" are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0016] Embodiment Please refer to Figures 1-6 , the present invention provides an embedded fiber ring single-radial constraint pneumatic soft driver, which is composed of an elastic layer 1, a filter joint 2, a fiber ring 4 and hard interference ball particles 3. The elastic layer 1 is a cylindrical structure, the elastic layer includes an upper bottom layer 1-1 and a lower bottom layer 1-3, the upper bottom layer 1-1 has a cylindrical air passage, the lower bottom layer 1-3 is closed, the filter joint 2 is embedded in the upper bottom layer 1-1 of the elastic layer 1, the hard interference ball particles 3 are filled in the inner cylindrical cavity of the elastic layer 1, the fiber ring 4 is embedded around the middle position inside the side wall 1-2 of the elastic layer, there are multiple fiber rings 4, and the multiple fiber rings 4 are arranged in an array along the axial direction of the driver.

[0017] The filter joint 2 is provided with a double-tooth shoulder 2-1, a hose or a hard pipe can be sleeved between the filter joint 2 and the cylindrical air passage of the elastic layer 1, and the three are radially locked by a hose clamp to ensure the connection airtightness. When the hose is directly sleeved on the double-tooth shoulder 2-1, it is located between the elastic layer 1 and the double-tooth shoulder 2-1, and then the air nozzle of the elastic layer 1 is radially locked by a cable tie to achieve sealing. When connecting the hard pipe, a hose needs to be sleeved inside the hard pipe and then sleeved on the filter joint 2, and then it is radially locked by a hose clamp to achieve sealing.

[0018] The filter joint 2 is cast integrally with the upper bottom layer 1-1 through the through hole on the flange shoulder 2-2. An equilateral triangular air inlet passage 2-3 is arranged inside the filter joint 2. The diameter of the inscribed circle of the cross-section of the equilateral triangular air inlet passage 2-3 is smaller than the diameter of the hard interference ball particles 3, preventing the hard interference ball particles 3 from blocking or passing through the air passage of the filter joint 2.

[0019] The diameter of the hard interference ball particles 3 is determined by the unit spacing of the fiber ring 4. The sizes of the hard interference ball particles 3 in the same driver are not unique. Single-size ball particles can be filled, or different-size ball particles can be filled in a mixture. During positive pressure driving, the radial expansion of the side wall 1-2 of the elastic layer is restricted. During negative pressure driving, the fiber ring 4 can retract with the inner wall of the elastic layer 1, squeezing the hard interference ball particles 3, increasing the interaction force between the hard interference ball particles 3, and enhancing the stiffness of the driver.

[0020] The fiber ring 4 is a circular cross-section ring structure. The material is selected to have the characteristic of axial tensile strength but not compressive strength. It is formed into an annular belt by binding the two ends of the textile thread to each other. The annular structure gives it the characteristic of radial tensile strength but not compressive strength.

[0021] As Figure 6 shown, by combining three drivers in parallel and using the secondary casting process to bond and combine the three drivers in parallel, the functions of stiffness enhancement and multi-directional bending can be achieved simultaneously through the positive and negative air pressure combinations of each driver.

[0022] The working process of the driver is as follows: During positive pressure driving, high-pressure gas enters the cavity of the elastic layer 1 through the air passage of the filter joint 2. The elastic layer 1 has a tendency to expand radially. At this time, the fiber ring 4 embedded inside the side wall 1-2 of the elastic layer restricts the radial expansion of the elastic layer 1, and the deformation in the axial direction is not restricted. Under the constraints of the upper bottom layer 1-1 and the lower bottom layer 1-3, the driver elongates axially. Due to the radial constraint of the fiber ring 4, the internal filled ball particles can only flow along the axis direction of the elastic layer 1 under the action of gravity at this time. When the driver recovers, the upper bottom layer 1-1 and the lower bottom layer 1-3 return to the initial state, and at the same time push the internal filled ball particles to restore the initial filling state, effectively avoiding the problem of particle accumulation caused by the expansion of the driver. The elongation of the driver can be adjusted by controlling the driving pressure. When the driver is driven by negative pressure, the elastic layer 1 has a tendency to contract radially. Since the fiber ring 4 is embedded inside the side wall 1-2 of the elastic layer, the fiber ring 4 can radially contract with the side wall 1-2 of the elastic layer, squeezing the hard interference ball particles 3, increasing the interaction force between the hard interference ball particles 3, and enhancing the stiffness of the driver. The stiffness of the driver can be adjusted by controlling the input pressure.

[0023] Therefore, the present invention adopts the above-mentioned single-radial constraint pneumatic soft actuator with an embedded fiber ring to achieve the positive and negative pressure dual-driving characteristics of the particle-interfered soft actuator. Since the fiber ring is embedded inside the side wall of the elastic layer, when positive pressure is introduced into the cavity of the soft actuator, the radial expansion of the side wall of the elastic layer of the actuator is restricted. At this time, the internal filling spherical particles can only flow along the axis direction of the actuator under the action of gravity, effectively avoiding the problem of random multi-directional recombination of particles, enhancing the shape retention ability of the particle-interfered soft actuator. At the same time, the deformation of the actuator in the axial direction is not restricted, and the fiber ring can move axially with the elastic layer. Therefore, the actuator can achieve axial elongation under positive pressure. During negative pressure driving, under the action of atmospheric pressure, the fiber ring retracts with the inner wall of the elastic layer, squeezing the hard interference spherical particles, increasing the interaction force between the hard interference spherical particles, and enhancing the stiffness of the actuator. By combining three actuators in parallel and using different air pressure combinations, multi-directional bending can be achieved, thus solving the problems of single movement direction and complex combination method of pneumatic soft actuators in the prior art.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A pneumatic soft actuator with single radial constraint and embedded fiber ring, characterized in that: It includes a driver, and there are three of them. The three drivers all include an elastic layer and a filter joint. The filter joint is embedded in the elastic layer. The elastic layer is set to a cylindrical structure. The interior of the elastic layer is filled with hard interference ball particles. A fiber ring is embedded around the side wall of the elastic layer. There are multiple fiber rings, and the multiple fiber rings are arranged in a row along the axial direction of the driver.

2. The fiber ring-embedded single radial constraint pneumatic soft actuator according to claim 1, characterized in that: The fiber ring is formed by binding two ends of a textile line into a ring structure. The fiber ring is arranged as a circular cross-section ring structure. The fiber ring is made of a textile material with axial tensile strength but not compressive strength.

3. The pneumatic soft actuator with embedded fiber ring and single radial constraint according to claim 2, characterized in that: The lower bottom layer of the elastic layer is closed, and the upper bottom layer is provided with a cylindrical air passage, the cylindrical air passage adopts a thickening design, and the cylindrical air passage is connected to the filter joint.

4. The fiber ring-embedded single radial constraint pneumatic soft actuator according to claim 3, characterized in that: A double-toothed shoulder is provided on the side of the filter joint, a connecting pipe is provided between the double-toothed shoulder and the cylindrical air duct, the double-toothed shoulder is connected to the pipe, a flange shoulder is provided at the lower end of the filter joint, a through hole is provided on the flange shoulder, and the through hole is cast together with the elastic layer.

5. The fiber ring-embedded single radial constraint pneumatic soft actuator according to claim 4, characterized in that: An equilateral triangle air inlet is arranged in the filter joint, and the inscribed circle of the cross section of the equilateral triangle air inlet is smaller than the diameter of the hard interference ball particles.

6. The fiber ring-embedded single radial constraint pneumatic soft actuator according to claim 5, characterized in that: The diameter of the hard interference ball particles is determined by the fiber ring unit spacing, and the diameter of the hard interference ball particles is not unique.

7. The fiber ring-embedded single radial constraint pneumatic soft actuator according to claim 6, characterized in that: The three actuators are combined in parallel through secondary pouring and bonding, and the positive and negative air pressure combination of the three actuators simultaneously realizes stiffness enhancement and multi-directional bending.

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