Multi-degree of freedom electrically driven soft actuator

Abstract

This invention discloses a multi-degree-of-freedom electrically driven soft actuator, which has a hexahedral structure. It includes: connectors located at the eight vertices of the hexahedral structure; an upper end plate and a lower end plate connected to the connectors located on the upper and lower end faces of the actuator, respectively; a flexible hinge located between the upper and lower end faces and fixed to each connector; and drive fibers arranged diagonally along the four sides of the actuator, with their ends fixed to the connectors and connected to an external power source. When the drive fibers are energized, they contract and deform the flexible hinges. Different drive fiber combinations activate strategies to achieve multi-degree-of-freedom deformation of the actuator. When the drive fibers are de-energized, they and the flexible hinges automatically recover, restoring the actuator to its initial configuration. This actuator features low-voltage drive, light weight, compact structure, and simple manufacturing process, making it suitable for the construction and application of various soft robot systems.

Description

Technical Field

[0001] This invention relates to the field of software actuators, and in particular to a multi-degree-of-freedom electrically driven software actuator. Background Technology

[0002] With the rapid development of robotics technology and the deepening integration of science and engineering, significant progress has been made in key areas such as manufacturing, medicine, and the military. These breakthroughs have not only improved production efficiency but also expanded the adaptability and execution capabilities of robots in complex tasks, profoundly impacting human production methods and quality of life. As the core component of a robot system, the performance of the actuator directly determines the realization of robot functions, the accuracy of motion, and its adaptability to complex environments. Traditional rigid robots, due to their rigid structure and bulky size, exhibit poor flexibility in dynamic environments, making it difficult to meet the requirements of flexible deformation, human-robot collaboration, and multi-modal response. In contrast, soft robots and their soft actuators possess inherent compliance, enabling smooth and continuous motion, thus demonstrating enormous application potential in complex and dynamic work scenarios. However, existing soft actuators have limited degrees of freedom, mostly only capable of linear or bending actuation in a single direction, and lack structural stability, making them prone to failure under multi-directional forces. This significantly limits their application range in complex tasks, especially given the increasing demand for multi-degree-of-freedom collaborative control. Therefore, it is necessary to research a novel soft actuator to address these issues. Summary of the Invention

[0003] The purpose of this invention is to address the problems existing in the prior art by providing a multi-degree-of-freedom electrically driven soft actuator that enables various deformation modes such as contraction, bidirectional torsion, and omnidirectional bending, thereby significantly improving the degree of freedom of drive and task adaptability.

[0004] The technical solution adopted in this invention is as follows:

[0005] A multi-degree-of-freedom electrically driven soft actuator, characterized in that it includes several connectors, an upper end plate, a lower end plate, a flexible hinge, and a drive fiber;

[0006] The actuator has a hexahedral structure;

[0007] Several connectors are located at the eight vertices of the hexahedral structure;

[0008] The upper and lower end plates are respectively connected to connectors located on the upper and lower end faces of the actuator, so that the connectors on the upper and lower end faces of the actuator are kept on the same plane to maintain the stability of the actuator during deformation; the upper and lower end plates also have four threaded holes for rapid assembly of the actuator system;

[0009] The flexible hinge is located between the upper and lower end faces and is fixedly connected to each connector, forming the support structure of the actuator.

[0010] The drive fibers are arranged diagonally along each side of the actuator to form clockwise drive fibers and counterclockwise drive fibers. The ends of the drive fibers are fixed to connectors on the diagonal sides of the sides and connected to an external power source.

[0011] When an external power source supplies power to the drive fiber, the drive fiber contracts and causes the flexible hinge to deform; different combinations of drive fibers activate strategies to achieve multi-degree-of-freedom deformation of the actuator; when the drive fiber is de-energized, the drive fiber and flexible hinge automatically recover and cause the actuator to return to its initial configuration.

[0012] Furthermore, each connector includes: a fiber hole, a hinge hole, a slot, and a wire hole;

[0013] Each fiber hole is arranged along the diagonal direction of the hexahedron's side surface to fix the driving fiber;

[0014] Each hinge hole faces the geometric center of the hexahedral actuator and is used to fix the flexible hinge.

[0015] The slot is used for the upper and lower end plates to engage with the connectors located on the upper and lower ends of the actuator, respectively, to stably fix the upper and lower end plates and to enable quick assembly and disassembly of the end plates.

[0016] The wire hole is used for connecting an external power source to the drive fiber via a wire. Each drive fiber is independently connected to the external power source via a wire, so as to realize independent control of each drive fiber, thereby realizing multi-degree-of-freedom deformation control of the actuator.

[0017] Furthermore, the flexible hinge is an eight-directional radial support structure, with eight rods extending along different spatial directions with the central node as the reference, and connected to the hinge holes at the eight vertices of the hexahedral structure actuator, thereby forming a stable support frame with good elastic recovery capability.

[0018] Furthermore, the connector's slot has a right-angle structure.

[0019] Furthermore, the flexible hinge is made of thermoplastic polyurethane material by 3D printing.

[0020] Furthermore, the driving fiber has a cylindrical structure and is made of a combination of liquid crystal elastomer material and metal heating coil.

[0021] Furthermore, the actuator's ability to achieve multi-degree-of-freedom deformation based on different drive fiber combination activation strategies includes:

[0022] When all drive fibers are activated simultaneously, the actuator undergoes overall contraction and deformation;

[0023] When the four drive fibers arranged clockwise on the four sides are activated, the actuator undergoes forward torsional deformation.

[0024] When the four drive fibers arranged counterclockwise along the four sides are activated, the actuator produces a reverse torsional deformation.

[0025] First, activate the clockwise and counterclockwise drive fibers on the first side to achieve bending on that side. Then, activate the drive fibers on that side and the adjacent second side that intersect at the apex to achieve bending at the intersection of the two sides. Next, continue activating the clockwise and counterclockwise drive fibers on the second side to achieve bending on the second side. This process is repeated cyclically, allowing the actuator to achieve omnidirectional bending deformation.

[0026] Furthermore, the connector, upper end plate, and lower end plate are all made of polylactic acid material through 3D printing.

[0027] Furthermore, both the upper and lower end plates are provided with multiple threaded holes for connecting multiple actuators.

[0028] A soft robot based on any of the described multi-degree-of-freedom electrically driven soft actuators.

[0029] The beneficial effects of this invention are:

[0030] The multi-degree-of-freedom electrically driven soft actuator of this invention achieves a balance between flexibility and strength through an eight-directional radial flexible hinge and a multi-point supported connector structure, exhibiting excellent structural stability. The drive fibers support independent control and can achieve various deformation modes such as contraction, bidirectional torsion, and omnidirectional bending according to different activation combinations, significantly improving the actuation degree of freedom and task adaptability. The main structural components are prepared by 3D printing, which simplifies the manufacturing process, increases precision, and significantly improves overall assembly efficiency and control accuracy. Thus, it provides a novel multi-degree-of-freedom electrically driven soft actuator with a reasonable structure, flexible deformation, and strong scalability for fields such as soft robots, medical devices, detection equipment, and flexible operations in space-constrained environments. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the multi-degree-of-freedom electrically driven software actuator structure of the present invention;

[0032] Figure 2 This is a schematic diagram of the connector for the multi-degree-of-freedom electrically driven software actuator of the present invention;

[0033] Figure 3This is a schematic diagram of the flexible hinge of the multi-degree-of-freedom electrically driven soft actuator of the present invention;

[0034] Figure 4 This is a schematic diagram of the deformation of the multi-degree-of-freedom electrically driven soft actuator of the present invention, wherein (a) contraction deformation, (b) bending deformation, and (c) torsional deformation;

[0035] Among them, 1. upper end plate; 2. connector; 3. flexible hinge; 4. drive fiber; 5. lower end plate; 6. threaded hole; 7. fiber hole; 8. hinge hole; 9. slot; 10. wire hole. Detailed Implementation

[0036] The present invention will be further explained below with reference to the accompanying drawings.

[0037] A multi-degree-of-freedom electrically driven soft actuator includes several connectors 2, an upper end plate 1, a lower end plate 5, flexible hinges 3, and drive fibers 4. The actuator has a hexahedral structure. The connectors 2 are located at the eight vertices of the hexahedral structure. The upper end plate 1 and the lower end plate 5 are respectively connected to the connectors 2 located on the upper and lower end faces of the actuator, so that the connectors 2 on the upper and lower end faces of the actuator are kept on the same plane. The flexible hinges 3 are located between the upper and lower end faces and are fixedly connected to each connector 2, forming the support structure of the actuator. The drive fibers 4 are distributed... The actuator is arranged diagonally along each side, forming a clockwise drive fiber 4 and a counterclockwise drive fiber 4. The ends of the drive fibers 4 are fixed to connectors 2 on the diagonal sides and connected to an external power source. When the external power source powers the drive fibers 4, the drive fibers 4 contract and cause the flexible hinge 3 to deform. Different combinations of drive fibers 4 activate strategies to achieve multi-degree-of-freedom deformation of the actuator. When the drive fibers 4 are de-energized, the drive fibers 4 and the flexible hinge 3 automatically recover and cause the actuator to return to its initial configuration.

[0038] Example 1:

[0039] like Figure 1 As shown, a multi-degree-of-freedom electrically driven soft actuator includes a connector 2, an upper end plate 1, a lower end plate 5, a flexible hinge 3, and a drive fiber 4; as Figure 2As shown, the connector 2 has two fiber holes 7, one hinge hole 8, one slot 9, and two wire holes 10 for connecting and fixing the upper end plate 1, the lower end plate 5, the flexible hinge 3, and the drive fiber 4. Multiple connectors 2 are located at the eight vertices of the hexahedron structure, with the fiber holes 7 arranged along the diagonal direction of the hexahedron's side surface and the hinge holes 8 facing the geometric center of the hexahedron. The flexible hinge 3 is connected through the hinge holes 8 of the connector 2, forming the support structure of the actuator. The upper end plate 1 and the lower end plate 5 are respectively connected to the slot 9 on the connector 2, ensuring that the connectors 2 on the upper and lower end faces are located on the same plane to maintain the stability of the actuator during deformation. The upper and lower end plates 5 also each have four threaded holes 6 for quick connection between multiple actuators.

[0040] like Figure 3 As shown, the flexible hinge 3 preferably adopts an eight-directional radial support structure, with eight rods extending radially from the central node along different spatial directions and connecting to multiple connectors 2, thereby forming a stable support frame with good elastic recovery capability.

[0041] like Figure 2 As shown, the slot 9 of the connector 2 has a right-angle structure, which is used to stably fix the upper end plate 1 and the lower end plate 5, and can realize the quick assembly and disassembly of the end plates.

[0042] The driving fiber 4 is a cylindrical structure with a diameter in the millimeter range, formed by combining liquid crystal elastomer material and a metal heating coil. It can rapidly contract and generate driving force after being powered by an external power source. The driving fiber 4 is arranged diagonally along the four sides of the actuator, with one clockwise driving fiber and one counterclockwise driving fiber on each side. It is positioned and fixed through fiber holes 7 and connected to an external power source via wires.

[0043] The specific embodiments of the present invention are as follows:

[0044] like Figure 1 and Figure 4 As shown, each drive fiber 4 is connected to an external power source through the wire hole 10 on the connector 2. When the external power source supplies power to the drive fiber 4, the drive fiber 4, as an active drive unit, can undergo reversible contraction and deformation. The flexible hinge 3, as a passive support unit, provides mechanical support for the overall configuration and defines the deformation path. By selecting different activation strategies for the drive fiber 4, the actuator can achieve various deformation modes: such as... Figure 4 As shown in (a), when all eight drive fibers 4 are activated simultaneously, the actuator undergoes overall contraction deformation; as Figure 4As shown in (c), when all four drive fibers 4 arranged clockwise on all sides are activated, the actuator produces a forward torsional deformation; when the drive fibers 4 arranged counterclockwise are activated, the actuator produces a reverse torsional deformation; as shown in (c). Figure 4 As shown in (b), the clockwise and counterclockwise drive fibers 4 on the first side are activated first to achieve bending of that side. Then, the drive fibers 4 intersecting at the apex on that side and the adjacent second side are activated to achieve bending at the intersection of the two sides. Subsequently, the clockwise and counterclockwise drive fibers 4 on the second side are activated to achieve bending of the second side. This process is repeated, and the actuator can achieve omnidirectional bending deformation. Furthermore, when the drive fibers 4 are de-energized, the actuator can quickly return to its initial configuration under its own restoring force and the elastic recovery of the flexible hinge 3.

Claims

1. A multi-degree-of-freedom electrically driven software actuator, characterized in that, It includes several connectors, an upper end plate, a lower end plate, a flexible hinge, and drive fibers; The actuator has a hexahedral structure; Several connectors are located at the eight vertices of the hexahedral structure; The upper end plate and the lower end plate are respectively connected to the connectors located on the upper end face and the lower end face of the actuator, so that the connectors on the upper end face and the lower end face of the actuator are respectively kept on the same plane; The flexible hinge is located between the upper and lower end faces and is fixedly connected to each connector, forming the support structure of the actuator. The drive fibers are arranged diagonally along each side of the actuator to form clockwise drive fibers and counterclockwise drive fibers. The ends of the drive fibers are fixed to connectors on the diagonal sides of the sides and connected to an external power source. When an external power source supplies power to the drive fiber, the drive fiber contracts and causes the flexible hinge to deform; different combinations of drive fibers activate strategies to achieve multi-degree-of-freedom deformation of the actuator; when the drive fiber is de-energized, the drive fiber and flexible hinge automatically recover and cause the actuator to return to its initial configuration. Each connector includes a hinge hole, and each hinge hole is oriented toward the geometric center of the hexahedral actuator. The flexible hinge is an eight-directional radial support structure, with eight rods extending to the hinge hole along different spatial directions with the central node as the reference.

2. The multi-degree-of-freedom electrically driven software actuator according to claim 1, characterized in that, Each connector also includes a fiber optic port, a slot, and a wire hole; Each fiber hole is arranged along the diagonal direction of the hexahedron's side surface to fix the driving fiber; The slot is used for the upper and lower end plates to engage with the connectors located on the upper and lower ends of the actuator, respectively, to stably fix the upper and lower end plates and to enable quick assembly and disassembly of the end plates. The wire hole is used for the wires of the external power supply to pass through and connect to the drive fiber. Each drive fiber is independently connected to the external power supply through the wire, so as to realize independent control of each drive fiber, thereby realizing multi-degree-of-freedom deformation regulation of the actuator.

3. The multi-degree-of-freedom electrically driven software actuator according to claim 2, characterized in that, The connector's slot has a right-angle structure.

4. The multi-degree-of-freedom electrically driven software actuator according to claim 1, characterized in that, The flexible hinge is made of thermoplastic polyurethane material through 3D printing.

5. The multi-degree-of-freedom electrically driven software actuator according to claim 1, characterized in that, The driving fiber has a cylindrical structure and is made of a combination of liquid crystal elastomer material and metal heating coil.

6. The multi-degree-of-freedom electrically driven software actuator according to claim 1, characterized in that, Depending on the activation strategy of different drive fiber combinations, the multi-degree-of-freedom deformations achievable by the actuator include: When all drive fibers are activated simultaneously, the actuator undergoes overall contraction and deformation; When the four drive fibers arranged clockwise on the four sides are activated, the actuator undergoes forward torsional deformation. When the four drive fibers arranged counterclockwise on the four sides are activated, the actuator produces a reverse torsional deformation. First, activate the clockwise and counterclockwise drive fibers on the first side to achieve bending of that side; then activate the drive fibers that intersect at the apex on that side and the adjacent second side to achieve bending at the intersection of the two sides; then continue to activate the clockwise and counterclockwise drive fibers on the second side to achieve bending of the second side, and so on, until the actuator achieves omnidirectional bending deformation.

7. The multi-degree-of-freedom electrically driven software actuator according to claim 1, characterized in that, The connector, upper end plate, and lower end plate are all made of polylactic acid material through 3D printing.

8. The multi-degree-of-freedom electrically driven software actuator according to claim 1, characterized in that, Both the upper and lower end plates are provided with multiple threaded holes, which are used for connecting multiple actuators.

9. A soft robot based on the multi-degree-of-freedom electrically driven soft actuator according to any one of claims 1-8.

Images