An elephant trunk arrayed flexible shell high degree of freedom soft robot

Abstract

The application discloses an elephant trunk arrayed flexible shell high degree of freedom soft robot, and belongs to the field of bionic soft robots, which is composed of multiple layers of deformation components arranged in an axial array, has 45 independent degrees of freedom, and the deformation component comprises four flexible shell units stacked in layers, the four flexible shell units are distributed in a square shape, and are respectively located at four corners of the square, wherein the flexible shell unit located at the upper left corner and the flexible shell unit located at the lower right corner are respectively fixedly adhered above the flexible shell unit located at the lower left corner and the flexible shell unit located at the upper right corner; and the four flexible shell units form a connecting part adhered to each other in the central region of the square. The soft robot is adapted to low-pressure pneumatic driving, has low energy consumption and low control threshold, has large elongation, large bending deformation capacity and stable force output, and meets the actual operation load demand of grasping, transferring, interactive operation, eating assistance and the like.

Description

Technical Field

[0001] This invention relates to the field of biomimetic soft robot technology, and in particular to a high-degree-of-freedom soft robot with an array of flexible shells resembling an elephant trunk. Background Technology

[0002] Early mainstream designs employed strain-constrained layer designs, which embedded circumferential, longitudinal, or helical constraint materials on or inside the surface of the soft actuator, relying on pneumatic actuation to achieve basic single deformations such as elongation, contraction, and planar bending. This was the most basic configuration design method for soft robots.

[0003] To enhance deformation capabilities, the academic community has developed various anisotropic optimization schemes: integrated fiber reinforcement, external flexible skeleton, lattice metamaterials, tensioned monoliths, and knitted heterostructures; topology optimization drives the geometry of the chambers; and the folding principle is used to construct differentiated aerodynamic chambers. By controlling the anisotropy of aerodynamic expansion, multimodal composite deformations such as bending, torsion, and elongation can be achieved.

[0004] By adopting the approach of parallel connection of independent drive units and modular combination of multiple software actuators, selective pneumatic excitation and timing control enable each unit to form antagonistic / cooperative motion modes, realizing extension, bending and compound spatial motion. This is the mainstream engineering solution to improve the motion flexibility of robots.

[0005] Subsequent innovative paradigms such as dot-matrix programmable enhancement, LCE artificial muscle integration, and pneumatic-rope hybrid decoupled drive have emerged, enabling deformation modal coupling, smooth switching of motion modes, and decoupling of multi-dimensional deformation. These have expanded the reachable workspace to a certain extent, reduced control difficulty, and improved environmental adaptability.

[0006] Current mainstream soft robot structural solutions all suffer from insurmountable design shortcomings, failing to meet the demands of precise and dexterous operations in unstructured environments. Firstly, traditional strain-constrained layer structures exhibit limited deformation patterns, capable only of simple basic deformations and incapable of complex spatial composite movements. Anisotropic reinforced structures, once formed, have fixed and non-reconfigurable configurations, and their deformation modes cannot dynamically adjust to external environments and operational tasks, resulting in extremely poor environmental adaptability. Secondly, multi-unit parallel integrated structures rely on redundant structures to gain motion degrees of freedom, leading to bulky and cumbersome robots. This not only contradicts the development trend of miniaturization and lightweight soft robots but also simultaneously increases the difficulty of mechanical structure design, the complexity of motion planning, and the overall control R&D costs. Summary of the Invention

[0007] The purpose of this invention is to provide a high-degree-of-freedom soft robot with an array of flexible shells resembling an elephant trunk, in order to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides a high-degree-of-freedom soft robot with an array of flexible shells resembling an elephant trunk. The robot comprises multiple deformable components arranged in an array along the axial direction, possessing 45 independent degrees of freedom. Each deformable component includes four stacked flexible shell units arranged in a square, located at the four corners of the square. The flexible shell unit located at the upper left corner and the flexible shell unit located at the lower right corner are respectively fixedly attached to the upper left and upper right corner flexible shell units. The four flexible shell units form a mutually adhered connection in the central region of the square.

[0009] Preferably, the flexible shell unit includes two symmetrically adhered flexible shells and a connector disposed between the two flexible shells, forming an independent and controllable pneumatic chamber between the two flexible shells.

[0010] Preferably, the flexible shell unit has a side injection port on its side.

[0011] Preferably, the flexible shell adopts an integrally molded structure with rounded corners on the outer contour edges. The whole shell is composed of six polygonal plates. The polygonal plates are connected by edges to form a closed space structure. The six polygonal plates include a pentagonal plate in the center, and two first isosceles trapezoidal plates, two trapezoidal plates and a second isosceles trapezoidal plate located on the outside of the pentagonal plate.

[0012] Preferably, the first isosceles trapezoidal plate, the trapezoidal plate, and the second isosceles trapezoidal plate are all arranged at an angle to the pentagonal plate.

[0013] Preferably, the pentagonal plate has five sides, including two long right-angled sides that are perpendicular to each other and of equal length, two short right-angled sides that are perpendicular to the two long right-angled sides and of shorter length than the long right-angled sides, and a hypotenuse connecting the ends of the two short right-angled sides.

[0014] Preferably, the two first isosceles trapezoidal plates are connected by their upper bases and two long right-angled sides sharing a common edge, and the adjacent sides of the two first isosceles trapezoidal plates coincide. The two trapezoidal plates are connected by their upper bases and two short right-angled sides sharing a common edge, and the sides of the two trapezoidal plates coincide with the sides of the two first isosceles trapezoidal plates. The upper base of the second isosceles trapezoidal plate is connected by its hypotenuse sharing a common edge, and the two sides of the second isosceles trapezoidal plate coincide with the other sides of the two first isosceles trapezoidal plates, thereby forming a closed spatial structure.

[0015] Preferably, the deformable component adopts a pure pneumatic distributed independent drive control mode, which selectively excites and sequentially coordinates each pneumatic chamber through a multi-way pneumatic regulating valve to achieve three motion modes.

[0016] Preferably, the three motion modes are as follows: Basic motion modes: Apply differential air pressure to the left and right flexible shell units to achieve deflection and rotation in the Y-axis direction; apply differential air pressure to the upper and lower flexible shell units to achieve spatial bending in the Z-axis direction; and apply synchronous air pressure to all flexible shell units to achieve overall elongation in the Z-axis direction. Composite three-dimensional motion modes: various basic motion modes are arbitrarily superimposed and coupled to generate continuous and smooth arbitrary three-dimensional spatial motion trajectories; Multi-point local deformation mode: 45 independent degrees of freedom are individually controlled, supporting asynchronous and differentiated local deformation at different positions of the fuselage, and realizing adaptive and precise control of the shape.

[0017] Therefore, the present invention employs the above-mentioned elephant trunk-inspired arrayed flexible shell high-degree-of-freedom soft robot, which has the following beneficial effects: (1) The first arrayed flexible shell stacked biomimetic configuration abandons the traditional strain limiting layer and redundant parallel integration design concept. Without increasing the size of the whole machine, it achieves 45 highly integrated motion degrees of freedom within a compact length of 315mm. The degree of freedom density far exceeds that of existing similar products, achieving both miniaturization and high degree of freedom.

[0018] (2) The high degree of freedom redundancy design fundamentally avoids the defects of dead zones and unreachable areas in the workspace of traditional robots, and can generate arbitrary three-dimensional spatial trajectories. The tracking ability of complex curved surfaces and spatial curves is greatly improved. It can realize the three-dimensional composite large motion of the whole machine, and can realize multi-point asynchronous local adaptive deformation. The shape control freedom is high, and the task adaptability is far superior to the traditional soft robot with single mode and fixed structure.

[0019] (3) This invention draws on the motion mechanism of elephant trunk muscles and hydrostatic skeleton, and proposes a new design concept of arrayed flexible shell structure and structure stacking. Under the constraint of a compact length of only 315mm, it achieves 45 independent motion degrees of freedom, with a degree of freedom density of 142.9DOF / m, which greatly surpasses the existing pneumatic and hybrid drive soft robots. It breaks through the inherent design drawbacks of traditional soft robots that rely on structural redundancy and increase the size of the whole machine to obtain degrees of freedom, and achieves a combination of small volume, high degree of freedom and high integration.

[0020] (4) The whole machine adopts a pneumatic drive design with fully flexible materials, without the need to embed rigid media such as skeletons and connecting rods. It retains the natural passive and compliant characteristics of soft robots. When in contact with people, fragile objects, or complex environments, there is no rigid impact, and the interaction safety is high. It is suitable for close human-machine interaction scenarios such as medical rehabilitation and elderly care. The invention can realize the large-scale three-dimensional flexible motion of the whole machine through the superposition of basic motion modes, and can realize multi-point asynchronous local differential deformation by using multi-degree-of-freedom independent control. It has the ability to adapt to form self-adaptive fine adjustment, and is suitable for unstructured environments, irregular object operation and fine interaction tasks. Its functional flexibility is far superior to that of traditional single-body deformable soft robots.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the assembly of a flexible shell high-degree-of-freedom soft robot with an array resembling an elephant trunk, according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a flexible shell high-degree-of-freedom soft robot with an array resembling an elephant trunk, according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the deformation structure of a high-degree-of-freedom soft robot with an arrayed flexible shell resembling an elephant trunk, according to an embodiment of the present invention. In the diagram, A represents the basic motion mode deformation, B represents the composite three-dimensional motion mode deformation, and C represents the multi-point local deformation mode deformation. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0024] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0025] Example like Figures 1-2 As shown, this invention provides a high-degree-of-freedom soft robot with an array of flexible shells resembling an elephant's trunk. It consists of multiple layers of deformable components arranged in an axial array. Each layer of deformable component has three degrees of freedom (extension and omnidirectional bending), and the robot is configured with 15 layers, resulting in 45 independent degrees of freedom. Each deformable component includes four stacked flexible shell units arranged in a square, located at the four corners of the square. The flexible shell unit located at the upper left corner and the flexible shell unit located at the lower right corner are respectively fixedly attached to the upper left and upper right corner flexible shell units. The four flexible shell units form an adhesive connection in the central region of the square.

[0026] The flexible shell unit comprises two symmetrically adhered flexible shells and a connector positioned between them. An independently controllable pneumatic chamber is formed between the two shells. Distributed, independent air pressure control of each pneumatic chamber drives the robot to achieve various motion modes. Side injection interfaces are provided on the sides of the flexible shell unit.

[0027] The flexible shell adopts a one-piece molded structure with rounded corners on its outer contour edges. It is composed of six polygonal plates connected by their edges to form a closed spatial structure. The six polygonal plates include a central pentagonal plate, and two first isosceles trapezoidal plates, two trapezoidal plates, and one second isosceles trapezoidal plate positioned outside the pentagonal plate. The first isosceles trapezoidal plates, the trapezoidal plates, and the second isosceles trapezoidal plate are all arranged at an angle to the pentagonal plate.

[0028] The pentagonal plate has five sides, including two long right-angled sides that are perpendicular to each other and of equal length, two short right-angled sides that are perpendicular to the two long right-angled sides and of shorter length, and a hypotenuse connecting the ends of the two short right-angled sides.

[0029] Two first isosceles trapezoidal plates are connected by their upper bases and two long right-angled sides sharing a common edge, and their adjacent sides coincide. The two trapezoidal plates are also connected by their upper bases and two short right-angled sides sharing a common edge, and their sides coincide with the sides of the two first isosceles trapezoidal plates. The upper base of the second isosceles trapezoidal plate is connected by its hypotenuse sharing a common edge, and its two sides coincide with the other sides of the two first isosceles trapezoidal plates, thus forming a closed spatial structure. The flexible shell units are all fixed and adhered to each other through the first isosceles trapezoidal plates.

[0030] The soft robot is a purely flexible pneumatically driven structure without introducing any rigid medium. It is entirely made of flexible polymer materials in one piece or modularly assembled. The overall axial length is constrained to 315mm, and 45 independent and controllable degrees of freedom are constructed within a limited and compact length, with a degree of freedom density of 142.9DOF / m.

[0031] like Figure 3 As shown, the deformable component adopts a pure pneumatic distributed independent drive control mode, which selectively excites and sequentially coordinates the pneumatic chambers through multi-way pneumatic regulating valves to achieve the following three modes: Basic motion modes: Apply differential air pressure to the left and right flexible shell units to achieve deflection and rotation in the Y-axis direction (for example, if the two left rows of flexible shell units are filled with air pressure while the two right rows are not, the soft robot will bend to the right). Apply differential air pressure to the upper and lower flexible shell units to achieve spatial bending in the Z-axis direction. Apply synchronous air pressure to all flexible shell units to achieve overall elongation in the Z-axis direction. Composite 3D motion modes: The basic deformations such as Y-axis deflection and rotation, Z-axis spatial bending, and Z-axis axial elongation are coupled and coordinated in a time sequence. Each basic motion mode can be arbitrarily superimposed and coupled to generate a continuous and smooth arbitrary 3D spatial motion trajectory, eliminating the dead zone of traditional robot motion. Multi-point local deformation mode: 45 independent degrees of freedom can be controlled individually, supporting asynchronous and differentiated local deformation at different positions of the fuselage, and realizing adaptive and precise control of the shape.

[0032] The continuous integrated configuration of soft robots ensures smooth, compliant and controllable motion throughout the entire process, enabling full-space pose attainment and arbitrary shape transformation.

[0033] Therefore, this invention employs the aforementioned elephant trunk-inspired arrayed flexible shell high-degree-of-freedom soft robot, which is composed of a large number of independently adjustable muscle bundles. Each segment can independently achieve basic deformation of extension, bending, and torsion and can be arbitrarily coupled. It has the characteristics of being accessible throughout the entire workspace, continuous and smooth omnidirectional motion, and near-infinite-degree-of-freedom motion. This invention replicates this biomimetic motion mechanism and adopts the concept of arrayed flexibility and layered structure to achieve high-degree-of-freedom integration of the soft robot.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A flexible shell high-degree-of-freedom soft robot with an array resembling an elephant's trunk, characterized in that: Composed of multiple deformable components arranged in an axial array, it has 45 independent degrees of freedom. The deformable components include four flexible shell units stacked in layers. The four flexible shell units are distributed in a square and are located at the four corners of the square. The flexible shell unit located at the upper left corner and the flexible shell unit located at the lower right corner are fixedly attached to the upper left and upper right corner flexible shell units, respectively. The four flexible shell units form a connection part that is mutually adhered in the central region of the square.

2. The elephant trunk-like arrayed flexible shell high-degree-of-freedom soft robot according to claim 1, characterized in that: The flexible shell unit includes two symmetrically adhered flexible shells and a connector disposed between the two flexible shells, forming an independent and controllable pneumatic chamber between the two flexible shells.

3. The elephant trunk-inspired array flexible shell high-degree-of-freedom soft robot according to claim 1, characterized in that: The flexible shell unit has a side injection port on its side.

4. The elephant trunk-like arrayed flexible shell high-degree-of-freedom soft robot according to claim 2, characterized in that: The flexible shell adopts an integral molding structure with rounded corners on the outer contour edges. The whole is composed of six polygonal plates. The polygonal plates are connected by edges to form a closed space structure. The six polygonal plates include a pentagonal plate in the center, and two first isosceles trapezoidal plates, two trapezoidal plates and a second isosceles trapezoidal plate on the outside of the pentagonal plate.

5. The elephant trunk-like arrayed flexible shell high-degree-of-freedom soft robot according to claim 4, characterized in that: The first isosceles trapezoidal plate, the trapezoidal plate, and the second isosceles trapezoidal plate are all arranged at an angle to the pentagonal plate.

6. The elephant trunk-like arrayed flexible shell high-degree-of-freedom soft robot according to claim 4, characterized in that: The pentagonal plate has five sides, including two long right-angled sides that are perpendicular to each other and of equal length, two short right-angled sides that are perpendicular to the two long right-angled sides and of shorter length, and a hypotenuse connecting the ends of the two short right-angled sides.

7. The elephant trunk-inspired arrayed flexible shell high-degree-of-freedom soft robot according to claim 6, characterized in that: Two first isosceles trapezoidal plates are connected by their upper bases and two long right-angled sides sharing a common edge, and the adjacent sides of the two first isosceles trapezoidal plates coincide. The two trapezoidal plates are connected by their upper bases and two short right-angled sides sharing a common edge, and the sides of the two trapezoidal plates coincide with the sides of the two first isosceles trapezoidal plates. The upper base of the second isosceles trapezoidal plate is connected by its hypotenuse sharing a common edge, and the two sides of the second isosceles trapezoidal plate coincide with the other sides of the two first isosceles trapezoidal plates, thus forming a closed spatial structure.

8. The elephant trunk-like arrayed flexible shell high-degree-of-freedom soft robot according to claim 1, characterized in that: The deformable component adopts a pure pneumatic distributed independent drive control mode, which selectively excites and sequentially coordinates each pneumatic chamber through a multi-way pneumatic regulating valve to achieve three motion modes.

9. A high-degree-of-freedom soft robot with an array of flexible shells resembling an elephant's trunk, as described in claim 8, is characterized in that: The three motion modes are as follows: Basic motion modes: Apply differential air pressure to the left and right flexible shell units to achieve deflection and rotation in the Y-axis direction; apply differential air pressure to the upper and lower flexible shell units to achieve spatial bending in the Z-axis direction; and apply synchronous air pressure to all flexible shell units to achieve overall elongation in the Z-axis direction. Composite three-dimensional motion modes: various basic motion modes are arbitrarily superimposed and coupled to generate continuous and smooth arbitrary three-dimensional spatial motion trajectories; Multi-point local deformation mode: 45 independent degrees of freedom are individually controlled, supporting asynchronous and differentiated local deformation at different positions of the fuselage, and realizing adaptive and precise control of the shape.

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