A structure of a continuum robot with asymmetric stiffness aerodynamic drive
By using an asymmetric stiffness pneumatically driven continuum robot structure, the limitations of traditional continuum robots in connection and drive in complex environments are solved, achieving rapid response, compliant control and efficient operation, and improving the robot's environmental adaptability and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA UNIV OF GEOSCIENCES (WUHAN)
- Filing Date
- 2025-09-10
- Publication Date
- 2026-05-01
AI Technical Summary
Existing continuum robots have limitations in structural connection, driving method and motion characteristic control, which limits their efficient operation in complex environments. Traditional connection methods are complex and unreliable, and the driving system has slow response and low precision, making it difficult to achieve differentiated rigid-flexible characteristics.
Employing an asymmetric stiffness pneumatic drive method, the robot connects the joints through pneumatic semi-corrugated tubes and mortise and tenon structures, combined with nickel-titanium alloy wires and pneumatic modules, achieving rapid response and compliant control. The robot exhibits anisotropic stiffness characteristics in different directions, enhancing structural stability and motion flexibility.
It enables robots to operate efficiently in complex environments, improves response speed and control precision, enhances safety and environmental adaptability, ensures smooth and stable movement, and is suitable for flexible human-computer interaction scenarios with high safety requirements.
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Figure CN120839758B_ABST
Abstract
Description
A structure of a pneumatically driven continuum robot with asymmetric stiffness 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:
[0007] The robot has several sets of joints connected in series to form its main body structure.
[0008] A reversing assembly is provided between adjacent vertebrae. The reversing assembly includes two sets of symmetrically arranged pneumatic semi-bellows.
[0009] A threading module, through which several groups of the aforementioned joints are connected in series;
[0010] A pneumatic module, which is connected to the pneumatic semi-corrugated pipe, drives the pneumatic semi-corrugated pipe to deform;
[0011] The adjacent bone segments are connected by a mortise and tenon structure.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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.
[0019] The present invention discloses the following technical effects:
[0020] 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.
[0021] 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
[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 is a schematic diagram of the overall structure of the continuous robot with asymmetric stiffness pneumatic drive according to the present invention.
[0024] Figure 2 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.
[0025] Figure 3 is a side-view center section view of the overall structure of a segment of a continuous robot with asymmetric stiffness pneumatic drive provided in the example of the present invention.
[0026] Figure 4 is a schematic diagram of the structure of a joint;
[0027] Figure 5 is a lateral sectional view of the joint;
[0028] Figure 6 is a schematic diagram of the proximal and coccygeal vertebrae (I);
[0029] Figure 7 is a lateral sectional view of the proximal and coccygeal vertebrae (I).
[0030] Figure 8 is a schematic diagram of the proximal and coccygeal vertebrae II;
[0031] Figure 9 is a lateral sectional view of the proximal and coccygeal vertebrae (II).
[0032] Figure 10 is a schematic diagram of the structure of a pneumatic semi-corrugated pipe;
[0033] Figure 11 is a top-view central cross-sectional view of the pneumatic semi-bellows.
[0034] Figure 12 shows the bending state of the two bellows halves of a continuous robot with asymmetric stiffness pneumatic drive after inflation / deflation.
[0035] 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
[0036] 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 embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0037] 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.
[0038] Referring to Figures 1-12, the present invention provides a structure for a pneumatically driven continuum robot with asymmetric stiffness, comprising:
[0039] 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;
[0040] A reversing assembly is provided between adjacent vertebrae 1. The reversing assembly includes two sets of symmetrically arranged pneumatic semi-corrugated tubes 2.
[0041] The insertion module connects several groups of bone segments 1 in series.
[0042] The pneumatic module is connected to the pneumatic semi-corrugated tube 2 and drives the pneumatic semi-corrugated tube 2 to deform.
[0043] The adjacent bone segments 1 are connected by a mortise and tenon structure 8.
[0044] 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 force between each joint 1, ensuring the stability of the robot's main structure and the continuity of its movement. It also enables each joint 1 to have a restoring force, allowing the robot to return to its initial posture without bending when the air pressure inside the two sets of pneumatic semi-corrugated pipes 2 is zero and no driving force is generated.
[0045] 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.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] 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.
[0050] 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.
[0051] 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.
[0052] 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.
[0053] 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.
[0054] 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.
[0055] 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.
[0056] 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.
[0057] 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.
[0058] 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.
[0059] 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.
[0060] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope 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 robot consists of several vertices (1), which are connected in series to form the main body structure of the robot; a reversing assembly, which is provided between adjacent vertices (1), and includes two sets of symmetrically arranged pneumatic semi-corrugated (2) tubes; a threading module, which connects several sets of vertices (1) in series; and a pneumatic module, which is connected to the main body structure of the robot. The pneumatic semi-corrugated (2) tubes are connected to drive the deformation of the pneumatic semi-corrugated (2) tubes; wherein, the adjacent joints (1) are connected by a tenon and mortise structure; the tenon and mortise structure includes a tenon structure (7) and a mortise structure (8), the tenon structure (7) and the mortise structure (8) are respectively set on the adjacent joints (1), the tenon structure (7) and the mortise structure (8) are connected, the tenon structure (7) and the mortise structure (8) are both disc-shaped, and the connection of the adjacent joints (1) is achieved by mutual cooperation, so that the joints (1) rotate along the disc direction, and are tightly connected and cannot move in the direction perpendicular to the disc; two sets of arc grooves (3) are respectively set at both ends of the joints (1), and the two sets of arc grooves (3) located at the same end are symmetrically arranged. The symmetrically arranged arc groove structure weakens the bending stiffness in the horizontal direction. The pneumatic semi-corrugated (2) tubes are respectively installed in the arc grooves (3), and the pneumatic semi-corrugated (2) tubes located on the same side are connected in series.
2. 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.
3. The structure of a pneumatically driven continuum robot with asymmetric stiffness according to claim 2, 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.
4. The structure of a pneumatically driven continuum robot with asymmetric stiffness according to claim 3, characterized in that: 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) through the air pipe hole (6).
5. 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.
6. 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.
Citation Information
Patent Citations
Air pressure-motor cooperative driving super-redundant deformation continuum charging robot system
CN120902582A