Torsionally stiff wire-driven continuum robot

Abstract

A kind of anti-torsion line drive continuum robot, in system, multiple joints are sequentially connected to serve as the main structure of continuum robot, and the joints are connected to each other by spherical hinge cooperation, cylindrical body is lower part of joint and is internally centrally provided with ball socket, ball socket is provided with ball groove on inner spherical surface, ball head is upper part of joint, ball head is provided with ball lug on outer spherical surface, ball head is circumferentially rotatably contained in ball socket of adjacent joint and ball lug is slidably connected to ball groove of adjacent joint, end face disc is arranged outside cylindrical body, end face disc is circumferentially arranged with multiple drive line through holes, circular table is arranged between ball head and cylindrical body, circular table is in contact with end face disc of adjacent joint to limit maximum bending angle of joint;Multiple compression springs are located between adjacent two joints, and the compression springs are compressed to generate reaction force when the continuum robot is bent, to provide bending stiffness for the continuum robot, and at the same time, the action force is transmitted between adjacent joints step by step;Drive line passes through drive line through hole and the interior of compression spring, and the distal end of drive line is fixed with end face disc.

Description

Technical Field

[0001] The present invention relates to the technical field of continuum robots, in particular to an anti-torsion wire-driven continuum robot. Background Art

[0002] The aircraft engine is the heart of an aircraft, providing the power for safe and stable flight. Its reliability plays a crucial role in flight safety. However, due to its complex structure and its long-term operation in extreme environments such as high temperature and high pressure, engine blades are inevitably susceptible to damage such as cracks, chipping, and ablation. Failure to detect and address these damages in a timely manner can lead to catastrophic consequences.

[0003] Currently, the most common in-situ inspection method for aircraft engines in the field involves professionals inserting a handheld borescope into the engine for inspection. This method, limited by the borescope's degrees of freedom and rigidity, cannot reach all inspection points within the engine. Furthermore, it is inefficient and time-consuming. Therefore, the development of new in-situ inspection methods and technologies for aircraft engines is urgently needed.

[0004] Continuum robots, due to their high degrees of freedom and bending compliance, can adapt to narrow and complex environments and have broad application prospects in the field of in-situ inspection of aircraft engines. However, traditional central core continuum robots have low stiffness and suffer from torsion problems under the influence of their own weight bending moment, resulting in insufficient control accuracy and stability, which has limited their application and development.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the Invention

[0006] The present invention provides a torsion-resistant wire-driven continuum robot. By combining ball joint cooperation and ball groove sliding, the joint freedom is limited, which not only enhances the stability of the joint connection but also greatly enhances the torsion resistance of the robot. In addition, the frustum and compression spring can also enhance the bending stiffness of the robot and improve the load capacity.

[0007] A torsion-resistant wire-driven continuum robot comprising:

[0008] Multiple joints are connected in sequence to form the main structure of the continuum robot. The center of the joint is provided with a central hole running through the central axis. The joints are connected to each other through ball joints. The joints include:

[0009] The cylinder is the lower part of the joint and has a ball socket in the center. The inner spherical surface of the ball socket is provided with a ball groove.

[0010] The ball head is the upper part of the joint. A ball ear is provided on the outer spherical surface of the ball head. The ball head can be rotatably accommodated in the ball socket of the adjacent joint and the ball ear is slidably connected to the ball groove of the adjacent joint.

[0011] The end plate is arranged outside the cylinder, and a plurality of drive line through holes are arranged circumferentially on the end plate.

[0012] A frustum, which is provided between the ball head and the cylinder, the frustum contacts the end disk of the adjacent joint to limit the maximum bending angle of the joint;

[0013] A plurality of compression springs are located between two adjacent joints. When the continuum robot bends, the compression springs are compressed to generate a reaction force to provide bending stiffness for the continuum robot and simultaneously transmit the force step by step between adjacent joints.

[0014] The driving wire passes through the driving wire through hole and the interior of the compression spring, and the distal end of the driving wire is fixed to the end disk.

[0015] In the anti-torsion wire-driven continuum robot, the ball ear is a hemispherical structure, and the cross section of the ball groove is a semicircular arc groove.

[0016] In the anti-torsion wire-driven continuum robot, two ball ears are provided on the outer spherical surface of the ball head, and two ball grooves matching the ball ears are provided on the inner spherical surface of the ball socket.

[0017] In the anti-torsion wire-driven continuum robot, the center of the ball ear is flush with the center of the ball head, and the two ball ears are symmetrical about the central axis, and the two ball grooves are symmetrical about the central axis.

[0018] In the torsion-resistant wire-driven continuum robot, the ball groove extends upward from the bottom surface of the cylinder along the central axis on the spherical surface inside the ball socket, and the plane where the top cross section is located forms an angle of 60° with the central axis of the joint. Looking downward from the top surface of the joint, the ball groove and the ball ear are staggered at 90°.

[0019] In the anti-torsion wire-driven continuum robot, the size of the ball socket is larger than the ball head, and the ball heads and ball sockets in two adjacent joints are connected through transition fit.

[0020] In the anti-torsion wire-driven continuum robot, the top surface of the ball head is a plane perpendicular to the central axis, and has multiple slits evenly distributed along the circumferential direction. The depth of the slits is greater than half the height of the ball head, which is used to provide elastic deformation during assembly.

[0021] In the anti-torsion wire-driven continuum robot, the ball ears in two adjacent joints form a transition fit with the ball grooves, and the ball ears slide in the ball grooves and cannot escape from the ball grooves.

[0022] In the anti-torsion wire-driven continuum robot, when the continuum robot is subjected to a torsional moment, the ball grooves confine the ball ears therein, thereby limiting the relative rotational movement between the joints around the central axis.

[0023] In the anti-torsion wire-driven continuum robot, the cooperation between the ball head and the ball socket and the cooperation between the ball ear and the ball groove are lubricated with grease.

[0024] Compared with the prior art, the present invention has the following advantages: the present invention adopts a joint connection method of a ball hinge structure, and the ball head can rotate freely in the circumferential direction in the ball socket and is not easy to fall out, with high degree of freedom and good connection stability. The sliding fit of the ball ear and the ball groove in the ball hinge joint constrains the relative rotation between the joints around the central axis, greatly improving the torsion resistance of the robot. Grease lubrication is used at the joint joint to greatly reduce the friction between the joints and make the rotation of the joints smoother. The use of a frustum to limit the maximum bending angle of the joint, and the use of a compression spring to increase the supporting force between adjacent joints, and to play a role in transmitting the tension of the drive line, thereby improving the bending stiffness of the continuum robot and the flexibility of the bending action. When the maximum bending angle is reached, the frustum contacts the bottom surface of the end plate of the previous joint, and the stiffness is further enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are intended only to illustrate preferred embodiments and are not to be construed as limiting the present invention. It should be understood that the drawings described below are merely examples of the present invention, and that those skilled in the art will be able to derive other drawings from these drawings without inventive effort. Throughout the drawings, identical reference numerals are used to denote identical components.

[0026] In the attached figure:

[0027] FIG1 is a schematic diagram of the overall structure of a torsion-resistant wire-driven continuum robot according to an embodiment of the present invention;

[0028] FIG2 is a schematic diagram of the structure of the anti-torsion wire-driven continuum robot joint in an embodiment of the present invention. Figure One ;

[0029] FIG3 is a schematic diagram of the structure of the anti-torsion wire-driven continuum robot joint in an embodiment of the present invention. Figure Two ;

[0030] FIG4 is a front view of a torsion-resistant wire-driven continuum robot joint according to an embodiment of the present invention;

[0031] Fig. 5 is a top view of a torsion-resistant wire-driven continuum robot joint according to an embodiment of the present application;

[0032] Fig. 6 is a bottom view of a torsion-resistant wire-driven continuum robot joint according to an embodiment of the present application;

[0033] Fig. 7 is a cross-sectional view of two adjacent torsion-resistant wire-driven continuum robot joints according to an embodiment of the present application.

[0034] The present application will be further explained with reference to the drawings and embodiments. DETAILED DESCRIPTION

[0035] Embodiments of the present application will be described in more detail with reference to the drawings. Although specific embodiments of the present application are shown in the drawings, it should be understood that the present application can be embodied in various forms without being limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0036] It should be noted that certain terms are used throughout the present specification and claims which have particular meanings as set forth below. Those skilled in the art will understand that not all terms are used as they are defined in common dictionaries, and that terms used have the meanings defined below. To the extent there is any conflict between the definitions provided herein and the meanings as understood by those skilled in the art, the definitions provided herein control. The description and claims herein are not to be limited to the exclusive implementations described herein, but can be practiced with modifications and alterations within the scope and spirit of the present application. The description herein is intended to be illustrative, and not to limit the scope of the application. What is claimed as the application is set forth in the following claims.

[0037] For the purpose of promoting an understanding of the principles of the application, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will, nevertheless, be understood that no limitation of the scope of the application is intended by this specification. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the application as described herein are contemplated with the scope of the application as defined by the following claims.

[0038] As shown in Fig. 1, a torsion-resistant wire-driven continuum robot includes: Figures 1 to 7

[0039] a plurality of joints 1 connected in sequence to serve as the main structure of the continuum robot, the joints 1 being centrally provided with a central hole 9 extending along a central axis, the joints 1 being connected to each other by a ball joint,

[0040] a cylindrical body 4 provided at the lower part of the joint 1 and centrally provided with a spherical socket 5 inside, the inner spherical surface of the spherical socket 5 being provided with a ball groove 11,

[0041] ​The ball head 3 is the upper part of the joint 1. A ball ear 10 is provided on the outer spherical surface of the ball head 3. The ball head 3 can be rotatably accommodated in the ball socket 5 of the adjacent joint 1. The ball ear 10 is slidably connected to the ball groove 11 of the adjacent joint 1.

[0042] The end plate 6 is arranged outside the cylinder 4, and a plurality of drive line through holes 7 are arranged circumferentially on the end plate 6.

[0043] A frustum 8 is provided between the ball head 3 and the cylinder 4, wherein the frustum 8 contacts the end plate 6 of the adjacent joint 1 to limit the maximum bending angle of the joint 1;

[0044] A plurality of compression springs 2 are located between two adjacent joints 1. When the continuum robot bends, the compression springs 2 are compressed to generate a reaction force to provide bending stiffness for the continuum robot and simultaneously transmit the force step by step between adjacent joints 1.

[0045] The driving wire passes through the driving wire through hole 7 and the interior of the compression spring 2 , and the distal end of the driving wire is fixed to the end disk 6 .

[0046] In a preferred embodiment of the anti-torsion wire-driven continuum robot, the ball ear 10 is a hemispherical structure, and the cross section of the ball groove 11 is a semicircular arc groove.

[0047] In the preferred embodiment of the anti-torsion wire-driven continuum robot, two ball ears 10 are provided on the outer spherical surface of the ball head 3 , and two ball grooves 11 for matching the ball ears 10 are provided on the inner spherical surface of the ball socket 5 .

[0048] In a preferred embodiment of the torsion-resistant wire-driven continuum robot, the center of the ball ear 10 is flush with the center of the ball head 3, and the two ball ears 10 are symmetrical about the central axis, and the two ball grooves 11 are symmetrical about the central axis.

[0049] In a preferred embodiment of the torsion-resistant wire-driven continuum robot, the ball groove 11 extends upward from the bottom surface of the cylinder 4 on the inner spherical surface of the ball socket 5 along the central axis, and the plane where the top cross section is located forms an angle of 60° with the central axis of the joint 1. Looking downward from the top surface of the joint 1, the ball groove 11 and the ball ear 10 are staggered at 90°.

[0050] In a preferred embodiment of the anti-torsion wire-driven continuum robot, the size of the ball socket 5 is larger than the ball head 3, and the ball heads 3 and ball sockets 5 in two adjacent joints 1 are connected by transition fit.

[0051] In a preferred embodiment of the torsion-resistant wire-driven continuum robot, the top surface of the ball head 3 is a plane perpendicular to the central axis, and has multiple slits 12 evenly distributed along the circumferential direction. The depth of the slits 12 is greater than half the height of the ball head 3, which is used to provide elastic deformation during assembly.

[0052] In a preferred embodiment of the anti-torsion wire-driven continuum robot, the ball ears 10 in two adjacent joints 1 form a transition fit with the ball grooves 11 , and the ball ears 10 slide in the ball grooves 11 and cannot escape from the ball grooves 11 .

[0053] In a preferred embodiment of the torsion-resistant wire-driven continuum robot, when the continuum robot is subjected to a torsional moment, the ball grooves 11 confine the ball ears 10 therein, thereby limiting the relative rotational movement between the joints 1 around the central axis.

[0054] In a preferred embodiment of the anti-torsion wire-driven continuum robot, the cooperation between the ball head 3 and the ball socket 5 and the cooperation between the ball ear 10 and the ball groove 11 are lubricated with grease.

[0055] In one embodiment, the anti-torsion wire-driven continuum robot includes a plurality of joints 1 connected in sequence, which are the main structure of the entire continuum robot and are connected to each other through ball joints; a compression spring 2, which is located between the corresponding drive wire through holes 7 of two adjacent joints 1 and is limited by the drive wire passing through the inside.

[0056] Among them, the compression spring 2 generates a reaction force when the robot is bent, which can provide a certain bending stiffness for the continuum robot. At the same time, it can transmit the force step by step between adjacent joints, thereby making the bending movement of the robot more smooth.

[0057] like Figures 2 to 3 As shown, the upper part of the joint 1 is a ball head 3 and the lower part is a cylinder 4. A ball socket 5 is provided in the center of the cylinder 4, and an end plate 6 is provided on the outside. Sixteen drive line through holes 7 are evenly distributed along the circumference of the end plate 6; a frustum 8 is provided between the ball head 3 and the cylinder 4, and a center hole 9 is provided in the center of the entire joint 1 that passes through along the central axis; two opposing hemispherical ball ears 10 are provided on the outer spherical surface of the ball head 3, and two opposing ball grooves 11 with semicircular cross-sections are provided on the inner spherical surface of the ball socket 5.

[0058] Among them, the main axis inclination angle of the frustum 8 is 10°, which is used to limit the bending angle of the joint 1. In addition, when the bottom surface of the previous joint 1 contacts the frustum 8 of the next joint 1, the bending stiffness of the robot can be enhanced.

[0059] The center hole 9 can be used for tools such as cameras, searchlights, and grinding heads to pass through.

[0060] like Figures 4 to 5As shown, the center of the lug 10 is flush with the center of the ball head 3, and the two lugs 10 are symmetrical about the central axis of the joint 1. The top surface of the ball head 3 is a plane perpendicular to the central axis of the joint 1 and has four slits 12 evenly distributed along the circumference. The depth of the slits 12 is greater than half the height of the ball head 3. When the two joints 1 are assembled, the slits 12 elastically deform under pressure, reducing their width and, consequently, the entire ball head 3, allowing it to fit into the socket 5. Once assembled, the pressure on the slits 12 disappears, returning the slits to their original width, and the ball head 3 returns to its original shape, without affecting the fit accuracy.

[0061] like Figures 6 to 7 As shown, the ball groove 11 extends upward from the bottom surface of the cylinder 4 to the spherical surface inside the ball socket 5 along the central axis of the joint 1. The plane where the top cross section is located forms an angle of 60° with the central axis of the joint 1, and the two ball grooves 11 are symmetrical about the central axis of the joint 1. The cross-sectional shape is semicircular and the size forms a spherical sliding fit with the ball ear 10. Looking downward from the top surface of the joint 1, the ball grooves 11 and the ball ear 10 are staggered at 90°.

[0062] Furthermore, the shape of the ball socket 5 is larger than a hemisphere, and the ball heads 3 and the ball sockets 5 in two adjacent joints 1 form a transition fit, so that the ball heads 3 can rotate in the ball sockets 5 and are not easy to fall out;

[0063] Furthermore, the ball ears 10 in the two adjacent joints 1 form a transition fit with the ball grooves 11. The ball ears 10 can slide in the ball grooves 11 without affecting the circumferential rotation of the ball head 3 in the ball socket 5. When the robot is subjected to a torsional torque, the ball grooves confine the ball ears in the raceway, thereby limiting the relative rotational movement between the joints around the central axis, making the robot anti-torsion.

[0064] Furthermore, the cooperation between the ball head 3 and the ball socket 5 and the cooperation between the ball ear 10 and the ball groove 11 is lubricated with grease, which can reduce friction and make the rotation of the joint smoother.

[0065] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields. The above-mentioned specific embodiments are merely illustrative and instructive, and are not restrictive. A person skilled in the art, guided by this specification and without departing from the scope of protection of the claims of the present invention, may also devise various forms, all of which fall within the scope of protection of the present invention.

Claims

1. A torsion-resistant wire-driven continuum robot, characterized in that: These include, Multiple joints are connected in sequence to form the main structure of the continuum robot. The center of the joint is provided with a central hole running through the central axis. The joints are connected to each other through ball joints. The joints include: The cylinder is the lower part of the joint and has a ball socket in the center. The inner spherical surface of the ball socket is provided with a ball groove. The ball head is the upper part of the joint. A ball ear is provided on the outer spherical surface of the ball head. The ball head can be rotatably accommodated in the ball socket of the adjacent joint and the ball ear is slidably connected to the ball groove of the adjacent joint. The end plate is arranged outside the cylinder, and a plurality of drive line through holes are arranged circumferentially on the end plate. A frustum, which is provided between the ball head and the cylinder, the frustum contacts the end disk of the adjacent joint to limit the maximum bending angle of the joint; A plurality of compression springs are located between two adjacent joints. When the continuum robot bends, the compression springs are compressed to generate a reaction force to provide bending stiffness for the continuum robot and simultaneously transmit the force step by step between adjacent joints. A driving wire passes through the driving wire through hole and the interior of the compression spring, and a distal end of the driving wire is fixed to the end disk; Wherein, the ball ear is a hemispherical structure, and the cross section of the ball groove is a semicircular arc groove; The outer spherical surface of the ball head is provided with two ball ears, and the inner spherical surface of the ball socket is provided with two ball grooves matching the ball ears; The center of the ball ear is flush with the center of the ball head, and the two ball ears are symmetrical about the central axis, and the two ball grooves are symmetrical about the central axis; The ball groove extends upward from the bottom surface of the cylinder on the inner spherical surface of the ball socket along the central axis, and the plane where the top cross section is located forms an angle of 60 degrees with the central axis of the joint. When viewed from the top surface of the joint downward, the ball groove and the ball ear are staggered at 90 degrees. The ball socket is larger than the ball head, and the ball heads and ball sockets in two adjacent joints are connected by transition fit; The top surface of the ball head is a plane perpendicular to the central axis and has a plurality of slits evenly distributed along the circumferential direction. The depth of the slits is greater than half the height of the ball head, so as to provide elastic deformation during assembly. The ball ears in two adjacent joints form a transition fit with the ball grooves, and the ball ears slide in the ball grooves and cannot escape from the ball grooves.

2. The torsion-resistant wire-driven continuum robot according to claim 1, characterized in that: When the continuum robot is subjected to a torsional moment, the ball grooves confine the ball ears therein, thereby limiting the relative rotational motion between the joints around the central axis.

3. The torsion-resistant wire-driven continuum robot according to claim 1, characterized in that: The cooperation between the ball head and the ball socket and the cooperation between the ball ear and the ball groove are lubricated with grease.

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