Structure of pneumatic drive continuum robot with asymmetric rigidity

Abstract

The invention discloses a pneumatic drive continuum robot structure with asymmetric rigidity, which comprises a plurality of groups of joints which are sequentially connected in series to form a robot main body structure; the direction changing assemblies are arranged between the adjacent joints, each direction changing assembly comprises two sets of pneumatic semi-corrugated pipes which are symmetrically arranged, and the two sets of pneumatic semi-corrugated pipes are symmetrically arranged between the adjacent joints; the plurality of groups of joints are connected in series through the penetrating modules; the pneumatic module is connected with the pneumatic semi-corrugated pipe and drives the pneumatic semi-corrugated pipe to deform; wherein the adjacent joints are connected through a mortise and tenon joint structure. The robot has different motion characteristics in different directions and can adapt to complex and changeable working environments, and the environmental adaptability of the robot is improved. And two groups of symmetrically arranged pneumatic semi-corrugated pipes in the direction changing assembly are combined with the asymmetric rigidity characteristic, so that the robot is more flexible and accurate in steering, and complex action tracks can be completed.

Description

Technical Field

[0001] This invention relates to the field of robotics, and in particular to the structure of a pneumatically driven continuum robot with asymmetric stiffness. Background Technology

[0002] To overcome the limitations of rigid robots in complex environments, continuum robots have emerged. As a novel type of robot possessing flexible structures and highly redundant motion capabilities, it consists of multiple continuous flexible segments. Motion and shape changes are achieved by controlling the deformation of these flexible segments. It lacks obvious rigid links and discrete joints, instead relying on continuous flexible materials or structures to transmit motion and force. With its high flexibility, excellent environmental adaptability, and precise control capabilities, continuum robots have shown broad application prospects in numerous fields such as medicine, detection, and industrial operations. They offer unique advantages in scenarios like industrial inspection, minimally invasive medical surgery, and complex environment detection, becoming a research hotspot at the forefront of industry and technology.

[0003] However, as application scenarios become increasingly complex, the limitations of existing continuum robots in terms of structural connections, drive methods, and motion control are becoming more and more apparent. Traditional connection methods are not only complex but also unreliable; drive systems suffer from slow response and low precision; and it is difficult to achieve differentiated rigidity and flexibility characteristics on different planes, which greatly limits their efficient operation in complex environments. It is evident that existing technologies face many bottlenecks that urgently need to be overcome, and innovative continuum robot structures are urgently needed to overcome these technical challenges.

[0004] Based on the above-mentioned technical problems, the present invention provides a structure for a pneumatically driven continuum robot with asymmetric stiffness. Summary of the Invention

[0005] The purpose of this invention is to provide a structure for a pneumatically driven continuum robot with asymmetric stiffness, in order to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a structure for a pneumatically driven continuum robot with asymmetric stiffness, comprising: The robot has several sets of joints connected in series to form its main body structure. A reversing assembly is provided between adjacent vertebrae. The reversing assembly includes two sets of symmetrically arranged pneumatic semi-bellows. A threading module, through which several groups of the aforementioned joints are connected in series; A pneumatic module, which is connected to the pneumatic semi-corrugated pipe, drives the pneumatic semi-corrugated pipe to deform; The adjacent bone segments are connected by a mortise and tenon structure.

[0007] According to the structure of the asymmetric stiffness pneumatically driven continuum robot provided by the present invention, two sets of arc-shaped grooves are respectively provided at both ends of the joint, and the two sets of arc-shaped grooves located at the same end are symmetrically arranged. The pneumatic semi-bellows are respectively installed in the arc-shaped grooves, and the pneumatic semi-bellows located on the same side are connected in series.

[0008] According to the structure of the asymmetric stiffness pneumatically driven continuum robot provided by the present invention, an air nozzle is installed on the pneumatic semi-bellows at the head end, and the air nozzle is connected to the pneumatic module.

[0009] According to the structure of the asymmetric stiffness pneumatically driven continuum robot provided by the present invention, a reserved hole is provided at the center of the joint for passing through a cable.

[0010] According to the structure of the asymmetric stiffness pneumatically driven continuum robot provided by the present invention, the pneumatic module includes an air pump, and an air pipe hole is provided on the side wall of the reserved hole. The air pump extends into the reserved hole and is connected to the air nozzle through the air pipe hole.

[0011] According to the structure of the asymmetric stiffness pneumatically driven continuum robot provided by the present invention, the tenon and mortise structure includes a tenon structure and a mortise structure, the tenon structure and the mortise structure are respectively disposed on adjacent joints, and the tenon structure and the mortise structure are connected.

[0012] According to the structure of the asymmetric stiffness pneumatically driven continuum robot provided by the present invention, the insertion module includes a nickel-titanium alloy wire, and insertion holes are opened on the joints. The nickel-titanium alloy wire passes through the insertion holes and is fixed to the joints at both ends.

[0013] According to the structure of the asymmetric stiffness pneumatically driven continuum robot provided by the present invention, a threaded hole is provided on the end joint, and the threaded hole is used for external extension structure.

[0014] The present invention discloses the following technical effects: 1) This invention employs a pneumatic drive system, adjusting the input air pressure via a pneumatic control module to control the pneumatic semi-bellows. This drive system offers advantages such as fast response, simple control, and convenient operation and adjustment, enabling efficient and rapid switching of the robot's motion states. Furthermore, due to the combination of the pneumatic drive system and the pneumatic semi-bellows made of flexible materials, the robot exhibits natural soft-start characteristics and compliant force output during movement, effectively avoiding rigid impacts. When interacting with the environment or human body, this structure significantly enhances the system's safety and adaptability, making it particularly suitable for flexible human-machine interaction scenarios with high safety requirements. 2) Adjacent joints in this invention are connected via a mortise and tenon structure. This connection method not only ensures the stability and reliability of the joint connection, limits unnecessary displacement, and ensures accurate rotation, but also facilitates the disassembly and maintenance of the joints. The through-module connects several sets of joints in series, enhancing the overall strength and stability of the robot's main structure, allowing the robot to better withstand external forces during movement. 3) The continuum robot provided by this invention exhibits anisotropic stiffness characteristics in different directions. Specifically, in the horizontal direction, the symmetrically arranged arc-shaped groove structure weakens the bending stiffness in this direction, resulting in lower stiffness and susceptibility to elastic deformation. In the vertical direction, the introduction of mechanical limiting designs such as mortise and tenon structures effectively suppresses deformation, thus exhibiting higher structural stiffness. Compared to traditional continuum robots with symmetrical stiffness in all directions, the pneumatically driven continuum robot with asymmetric stiffness characteristics proposed in this invention can better adapt to complex and changing working environments, significantly improving the robot's environmental adaptability and motion flexibility in practical applications. The two sets of symmetrically arranged pneumatic semi-bellows in the direction-changing component, combined with the asymmetric stiffness characteristics, make the robot's steering more flexible and precise, enabling it to complete complex motion trajectories. Attached Figure Description

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is a schematic diagram of the overall structure of the continuous robot with asymmetric stiffness pneumatic drive according to the present invention. Figure 2 This is a top-view central cross-sectional view of the overall structure of the continuous robot with asymmetric stiffness pneumatic drive according to the present invention. Figure 3A side-view center cross-sectional view of the overall structure of a continuous robot with asymmetric stiffness and pneumatic drive, provided as an example of the present invention. Figure 4 This is a schematic diagram of the structure of a joint; Figure 5 This is a lateral sectional view of a bone joint; Figure 6 A diagram of the proximal and distal vertebrae. Figure I ; Figure 7 Side view of the proximal and distal vertebrae Figure I ; Figure 8 A diagram of the proximal and distal vertebrae. Figure II ; Figure 9 Side view of the proximal and distal vertebrae Figure II ; Figure 10 This is a schematic diagram of a pneumatic semi-bellows. Figure 11 This is a top-view center section view of a pneumatic semi-corrugated pipe. Figure 12 This is a diagram showing the bending state of two bellows halves of a continuous robot with asymmetric stiffness and pneumatic drive after inflation / deflation.

[0017] Among them, 1. joint; 2. pneumatic semi-corrugated; 3. arc groove; 4. air nozzle; 5. reserved hole; 6. air pipe hole; 7. tenon structure; 8. mortise structure; 9. through hole; 10. threaded hole. Detailed Implementation

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Reference Figures 1-12 This invention provides a structure for a pneumatically driven continuum robot with asymmetric stiffness, comprising: Segment 1, there are several groups of segments 1, and the groups of segments 1 are connected in series to form the main structure of the robot; A reversing assembly is provided between adjacent vertebrae 1. The reversing assembly includes two sets of symmetrically arranged pneumatic semi-corrugated tubes 2. The insertion module connects several groups of bone segments 1 in series. The pneumatic module is connected to the pneumatic semi-corrugated tube 2 and drives the pneumatic semi-corrugated tube 2 to deform. The adjacent bone segments 1 are connected by a mortise and tenon structure 8.

[0021] In operation, the pneumatic module drives the pneumatic semi-corrugated tubes 2 in the direction-changing assembly by adjusting the air pressure. When the robot needs to rotate in a certain direction, the pneumatic module inflates a set of pneumatic semi-corrugated tubes 2 in the corresponding direction. These tubes expand and deform under the air pressure. Since adjacent joints 1 are connected by tenon and mortise structures 8 and formed a stable whole by the through-modules, the expanded semi-corrugated tubes push the adjacent joints 1 to rotate relative to each other. Meanwhile, the other set of uninflated or underinflated pneumatic semi-corrugated tubes 2 restricts excessive rotation in the opposite direction, thereby achieving precise steering of the robot. When the robot needs to maintain its current posture, the pneumatic module can maintain the current air pressure state of the two sets of pneumatic semi-corrugated tubes 2, ensuring that the joints 1 are relatively stationary and stable, thus maintaining the overall posture of the robot. Throughout the process, the insertion module not only firmly connects several sets of joints 1, but also transmits the forces between each joint 1, ensuring the stability of the robot's main structure and the continuity of its movement. Furthermore, it provides restoring force between each joint 1, allowing the robot to return to its initial, unbent posture when the air pressure inside the two sets of pneumatic semi-corrugated tubes 2 is zero and no driving force is generated.

[0022] To further optimize the design, two sets of arc-shaped grooves 3 are provided at both ends of the joint 1, and the two sets of arc-shaped grooves 3 located at the same end are arranged symmetrically. The pneumatic semi-corrugated pipes 2 are installed in the arc-shaped grooves 3 respectively, and the pneumatic semi-corrugated pipes 2 located on the same side are connected in series.

[0023] The joint 1 is made of a rigid material (such as resin 3D printing), with two sets of arc-shaped grooves 3 at each end. The two sets of arc-shaped grooves 3 at the same end are symmetrically arranged. The curvature of the arc-shaped grooves 3 is adapted to the semi-circular cross-section of the pneumatic semi-corrugated tube 2, which can limit and guide the pneumatic semi-corrugated tube 2. The pneumatic semi-corrugated tubes 2 are installed in the arc-shaped grooves 3 respectively, and the pneumatic semi-corrugated tubes 2 on the same side are connected in series to ensure the consistency of deformation of the semi-corrugated tubes on the same side. The cross-section of the joint 1 is formed by symmetrically stretching a circle along the secant line. A quarter circle is cut from the four corners of the prototype, so that the diameter of the half circle formed after the mortise and tenon connection of adjacent joints 1 is slightly larger than the length of the corrugated structure of the pneumatic semi-corrugated tube 2, so as to reserve space for its deformation.

[0024] The scheme was further optimized by installing an air nozzle 4 on the pneumatic semi-corrugated pipe 2 at the first end, and the air nozzle 4 is connected to the pneumatic module.

[0025] An air nozzle 4 is installed on the pneumatic semi-corrugated pipe 2 at the first end. This air nozzle 4 is connected to the air pump in the pneumatic module through an air pipe to realize the transmission and control of gas. The design of the air nozzle 4 ensures the sealing of the connection with the air pipe, thus guaranteeing the stable operation of the pneumatic drive system.

[0026] The design has been further optimized by creating a pre-drilled hole 5 at the center of joint 1, which is used for cable installation.

[0027] A pre-drilled hole 5 is provided at the center of the joint 1. This pre-drilled hole 5 is used to thread cables through, making the cable layout more compact and avoiding exposure that may affect the robot's movement or appearance. At the same time, it provides space for future functional expansion.

[0028] Further optimization of the scheme: the pneumatic module includes an air pump, and an air pipe hole 6 is opened on the side wall of the reserved hole 5. The air pump extends into the reserved hole 5 and is connected to the air nozzle 4 through the air pipe hole 6.

[0029] The pneumatic module includes an air pump. An air pipe hole 6 is provided on the side wall of the reserved hole 5. The air pump extends into the reserved hole 5 and is connected to the air nozzle 4 on the first pneumatic semi-corrugated pipe 2 through the air pipe hole 6, forming a complete gas transmission path. This design reduces exposed pipelines, optimizes the overall structural layout, and ensures high efficiency in gas transmission.

[0030] The scheme is further optimized. The mortise and tenon structure 8 includes a tenon structure 7 and a mortise structure 8. The tenon structure 7 and the mortise structure 8 are respectively set on adjacent joints 1 and connected.

[0031] The mortise and tenon structure 8 includes a tenon structure 7 and a mortise structure 8, where the protruding part is the tenon structure 7 and the recessed part is the mortise structure 8. The two are respectively set on adjacent joints 1. Both the tenon structure 7 and the mortise structure 8 are disc-shaped. They connect adjacent joints 1 by fitting together, allowing the joint 1 to rotate along the direction of the disc (demonstrating flexibility), while it is tightly connected and cannot move in the direction perpendicular to the disc (demonstrating rigidity), exhibiting asymmetrical stiffness characteristics.

[0032] The scheme is further optimized. The insertion module includes a nickel-titanium alloy wire. Insertion holes 9 are opened on the joint 1. The nickel-titanium alloy wire passes through the insertion holes 9 and is fixed to the joint 1 at both ends.

[0033] By utilizing the superelasticity and shape memory effect of nickel-titanium alloy, the structural stability of multiple vertebrae 1 connected in series is enhanced, preventing the vertebrae 1 from loosening or falling apart during movement.

[0034] In a further optimized design, a threaded hole 10 is provided on the end segment 1, which is used for connecting an external extension structure.

[0035] A threaded hole 10 is provided on the end segment 1. The threaded hole 10 is used to connect an external extension structure (such as a rotatable hollow motor) to enable the continuous robot to achieve additional motion degrees of freedom such as vertical rotation, thereby expanding its working range and functional diversity.

[0036] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0037] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A structure for a pneumatically driven continuum robot with asymmetric stiffness, characterized in that, include: The bone segment (1) is provided in several groups, and the several groups of bone segments (1) are connected in series to form the main body structure of the robot; A reversing assembly is provided between adjacent vertebrae (1). The reversing assembly includes two sets of symmetrically arranged pneumatic semi-corrugated (2) tubes. The two sets of pneumatic semi-corrugated (2) tubes are symmetrically arranged between adjacent vertebrae (1). The penetrating module connects several groups of the vertebrae (1) in series. A pneumatic module is connected to the pneumatic semi-corrugated (2) tube and drives the pneumatic semi-corrugated (2) tube to deform. The adjacent bone segments (1) are connected by a tenon and mortise structure (8).

2. The structure of a pneumatically driven continuum robot with asymmetric stiffness according to claim 1, characterized in that: Two sets of arc grooves (3) are provided at both ends of the joint (1), and the two sets of arc grooves (3) located at the same end are arranged symmetrically. The pneumatic semi-corrugated (2) tubes are installed in the arc grooves (3) respectively, and the pneumatic semi-corrugated (2) tubes located on the same side are connected in series.

3. The structure of a pneumatically driven continuum robot with asymmetric stiffness according to claim 1, characterized in that: An air nozzle (4) is installed on the pneumatic semi-corrugated (2) pipe located at the first end, and the air nozzle (4) is connected to the pneumatic module.

4. The structure of a pneumatically driven continuum robot with asymmetric stiffness according to claim 3, characterized in that: A reserved hole (5) is provided at the center of the joint (1), and the reserved hole (5) is used to thread a cable.

5. The structure of a pneumatically driven continuum robot with asymmetric stiffness according to claim 4, characterized in that: The pneumatic module includes an air pump, and an air pipe hole (6) is provided on the side wall of the reserved hole (5). The air pump extends into the reserved hole (5) and is connected to the air nozzle (4) through the air pipe hole (6).

6. The structure of a pneumatically driven continuum robot with asymmetric stiffness according to claim 1, characterized in that: The tenon and mortise structure (8) includes a tenon structure (7) and a mortise structure (8). The tenon structure (7) and the mortise structure (8) are respectively set on adjacent joints (1), and the tenon structure (7) and the mortise structure (8) are connected.

7. The structure of a pneumatically driven continuum robot with asymmetric stiffness according to claim 1, characterized in that: The threading module includes a nickel-titanium alloy wire, and a threading hole (9) is provided on the joint (1). The nickel-titanium alloy wire passes through the threading hole (9) and is fixed to the joint (1) at both ends.

8. The structure of a pneumatically driven continuum robot with asymmetric stiffness according to claim 1, characterized in that: A threaded hole (10) is provided on the end segment (1), which is used for connecting an external extension structure.

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