Anti-torsion line-driven continuum robot

Abstract

In a system, a plurality of joints are sequentially connected to serve as a main body structure of the continuum robot, the joints are mutually connected through spherical hinge matching, a cylinder serves as the lower portion of the joints, a ball socket is arranged in the center of the interior of the cylinder, a ball groove is formed in the inner spherical surface of the ball socket, a ball head serves as the upper portion of the joints, and a ball lug is arranged on the outer spherical surface of the ball head. The ball head can be circumferentially and rotatably contained in the ball socket of the adjacent joint, the ball lug is in sliding connection with the ball groove of the adjacent joint, the end face disc is arranged on the outer side of the cylinder, a plurality of driving line through holes are circumferentially formed in the end face disc, the circular truncated cone is arranged between the ball head and the cylinder, and the circular truncated cone makes contact with the end face disc of the adjacent joint to limit the maximum bending angle of the joint; the multiple compressed springs are located between every two adjacent joints, and when the continuum robot is bent, the compressed springs are pressed to generate counter-acting force to provide bending rigidity for the continuum robot and transmit the counter-acting force step by step between the adjacent joints at the same time. The driving wire penetrates through the driving wire through hole and the interior of the pressure spring, and the far end of the driving wire is fixed to the end face disc.

Description

Technical Field

[0001] The 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 the aircraft, providing power guarantee for the safe and stable navigation of the aircraft, and its reliability plays a decisive role in the flight safety of the aircraft. However, the aircraft engine has a complex structure and works in extreme environments such as high temperature and high pressure for a long time. The engine blades will inevitably have cracks, falling pieces, ablation and other damages. If they are not discovered and handled in time, it will lead to catastrophic consequences.

[0003] At present, the commonly used in-situ inspection method for aircraft engines in the field is for professionals to insert a handheld borescope into the engine for inspection. This method is limited by the freedom and rigidity of the borescope, and cannot detect all inspection points in the engine. It also has low operating efficiency and time-consuming inspection. Therefore, it is urgent to develop new in-situ inspection methods and technologies for aircraft engines.

[0004] Due to its high degree of freedom and bending flexibility, the continuum robot can adapt to narrow and complex environments and has broad application prospects in the field of in-situ inspection of aero-engines. However, the traditional central core column continuum robot has low stiffness and torsion problems under the influence of its own weight bending moment, resulting in insufficient control accuracy and stability, which limits its 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, which limits the joint freedom by combining ball joint cooperation and ball groove sliding, thereby enhancing the stability of the joint connection and also greatly enhancing 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 comprises:

[0008] A plurality of joints are connected in sequence to form the main structure of the continuum robot. A central hole is provided in the center of the joint along 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, and a ball ear is arranged 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 in the circumferential direction of the end plate.

[0012] A truncated cone, which is arranged between the ball head and the cylinder, and the truncated cone 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 is bent, 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 far 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 arranged on the outer spherical surface of the ball head, and two ball grooves matching the ball ears are arranged 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 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° with the central axis of the joint. Looking downward from the top surface of the joint, the ball groove and the ball ear are arranged at 90° in an alternating manner.

[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 by 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 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, and 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 by 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 joint structure, 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 joint constrains the relative rotation between the joints around the central axis, greatly improving the robot's anti-torsion ability. Grease lubrication is used at the joint joint to greatly reduce the friction between the joints and make the rotation of the joints smoother. A frustum is used to limit the maximum bending angle of the joint, and a compression spring is used to increase the supporting force between adjacent joints and play a role in transmitting the tension of the driving 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] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of illustrating the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work. Moreover, the same reference numerals are used to represent the same components throughout the drawings.

[0026] In the attached picture:

[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] FIG. 2 is a schematic diagram of the structure of the torsion-resistant wire-driven continuum robot joint according to an embodiment of the present invention. Figure 1 ;

[0029] FIG. 3 is a schematic diagram of the structure of the anti-torsion wire-driven continuum robot joint in an embodiment of the present invention. Figure 2 ;

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

[0031] FIG5 is a top view of the torsion-resistant wire-driven continuum robot joint according to an embodiment of the present invention;

[0032] FIG6 is a bottom view of the torsion-resistant wire-driven continuum robot joint according to an embodiment of the present invention;

[0033] FIG. 7 is a cross-sectional schematic diagram of the joint assembly of two adjacent torsion-resistant wire-driven continuum robots according to an embodiment of the present invention.

[0034] The present invention is further explained below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0035] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0036] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0037] To facilitate understanding of the embodiments of the present invention, further explanation will be given below by taking specific embodiments as examples in conjunction with the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

[0038] like Figures 1 to 7 As shown, the torsion-resistant wire-driven continuum robot comprises:

[0039] A plurality of joints 1 are connected in sequence to form the main structure of the continuum robot. A central hole 9 is provided in the center of the joint 1 along the central axis. The joints 1 are connected to each other through ball joints. The joints 1 include:

[0040] The cylinder 4 is the lower part of the joint 1 and has a ball socket 5 in the center. The inner spherical surface of the ball socket 5 is 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, and 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 truncated cone 8 is provided between the ball head 3 and the cylinder 4, and the truncated cone 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 is bent, 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 the 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 far end of the driving wire is fixed to the end plate 6 .

[0046] In the 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 matching the ball ears 10 are provided on the inner spherical surface of the ball socket 5 .

[0048] In a preferred embodiment of the anti-torsion 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 arranged at 90° in an alternating manner.

[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 head 3 and the ball socket 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 a plurality of 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, and 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 groove 11 , and the ball ears 10 slide in the ball groove 11 and cannot escape from the ball groove 11 .

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

[0054] In the 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 torsion-resistant 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 interconnected 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 and can gradually transmit the force 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. 16 drive line through holes 7 are evenly distributed along the circumference of the end plate 6; a truncated cone 8 is provided between the ball head 3 and the cylinder 4, and a center hole 9 that passes through the entire joint 1 along the central axis is provided in the center; two opposite hemispherical ball ears 10 are provided on the outer spherical surface of the ball head 3, and two opposite ball grooves 11 with semicircular cross-sections are provided on the inner spherical surface of the ball socket 5.

[0058] Among them, the generatrix inclination angle of the truncated cone 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 truncated cone 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 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 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 there are 4 slits 12 evenly distributed along the circumferential direction, and 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 produce elastic deformation under the action of pressure, the slit width becomes smaller, and then the entire ball head 3 becomes smaller, so that it can enter the ball socket 5; after being assembled in place, the pressure on the slits 12 disappears, the slit width returns to its original size, and then the ball head 3 returns to its original state, without affecting the matching accuracy.

[0061] like Figure 6 to Figure 7 As shown, the ball groove 11 extends upward from the bottom surface of the cylinder 4 on 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 a semicircular arc, 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 ears 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, and 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 two adjacent joints 1 form a transition fit with the ball grooves 11, and 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, and 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 are described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields, and the above specific embodiments are only illustrative and instructive, rather than restrictive. A person of ordinary skill in the art can also make many forms under the guidance of this specification and without departing from the scope of protection of the claims of the present invention, all of which belong to the protection of the present invention.

Claims

1. A torsion-resistant wire-driven continuum robot, characterized in that: These include, A plurality of joints are connected in sequence to form the main structure of the continuum robot. A central hole is provided in the center of the joint along 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, and a ball ear is arranged 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 in the circumferential direction of the end plate. A truncated cone is disposed between the ball head and the cylinder, wherein the truncated cone 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 is bent, 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. The driving wire passes through the driving wire through hole and the interior of the compression spring, and the far end of the driving wire is fixed to the end disk.

2. The torsion-resistant wire-driven continuum robot according to claim 1, characterized in that: Preferably, the ball ear is a hemispherical structure, and the cross-section of the ball groove is a semicircular arc groove.

3. The torsion-resistant wire-driven continuum robot according to claim 1, characterized in that: 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.

4. The torsion-resistant wire-driven continuum robot according to claim 3, characterized in that: 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.

5. The torsion-resistant wire-driven continuum robot according to claim 1, characterized in that: 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° 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°.

6. The torsion-resistant wire-driven continuum robot according to claim 1, characterized in that: 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 by transition fit.

7. The torsion-resistant wire-driven continuum robot according to claim 1, characterized in that: 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, and is used to provide elastic deformation during assembly.

8. The torsion-resistant wire-driven continuum robot according to claim 1, characterized in that: 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.

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

10. 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 by grease.

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