Variable-stiffness continuum robot

Abstract

A variable-stiffness continuum robot , comprising a drive base (1), a first central hole (113) being provided in the middle of the drive base (1); a spring collet (12) is mounted inside the first central hole (113); a driving unit (11) is provided on a side wall of the drive base (1), ball socket units (4) being deflectably connected to the driving unit (11), and the other side of each ball socket unit (4) being rotatably connected to a steering ball unit (5), wherein the steering ball units (5) and the ball socket units (4) are alternately arranged; one end of the ball socket units (4) is rotatably connected to an end base unit (6); an elastic rod (2) passes through the steering ball units (5) and the ball socket units (4). By means of providing inner friction layer, middle friction layer and outer friction layer structures and using inflation and expansion of thin film airbags to compress each friction layer, the friction force between adjacent units is increased under the action of friction, such that a large friction locking torque is generated between adjacent series-connected units, thereby allowing changing the stiffness of bending of the whole continuum robot over a large range.

Description

A variable stiffness continuum robot TECHNICAL FIELD

[0001] The present application relates to the technical field of soft robots, in particular to a variable stiffness continuum robot. BACKGROUND

[0002] There are a large number of narrow equipment spaces, boiler inner walls, pressure vessels (heat exchangers, complete sets), and small-diameter equipment in energy petrochemical pressure equipment, which are difficult to realize efficient and reliable automatic non-destructive testing and detection maintenance, and are prone to cause dangerous hidden trouble and catastrophic accidents, therefore, it has become a hot and difficult problem in the industry to realize efficient and reliable intelligent non-destructive testing and detection maintenance in dangerous and special narrow space environments.

[0003] To solve the above problems, the existing technology often uses a continuum robot for non-destructive detection, due to its bendability, the continuum robot can be compatible with the contact object through continuous deformation and greatly reduce the contact stress, and has higher flexibility, safety and adaptability, and has unique advantages in minimally invasive surgery, disaster rescue, fragile object grabbing, narrow space and multi-obstacle environment operation, etc., however, due to the low stiffness of the continuum robot, its carrying capacity is poor, although the variable stiffness structure represented by the blocking structure solves the problem of low stiffness of the continuum robot to some extent, but there are still problems such as limited stiffness variation range and slow stiffness variation, therefore, we propose a variable stiffness continuum robot.

[0004] SUMMARY

[0005] The present application aims to provide a variable stiffness continuum robot, which can realize friction locking of adjacent units by extruding each friction layer with an air bag, thereby changing the bending stiffness of the robot and improving its carrying capacity.

[0006] To achieve the above purpose, the present application provides the following technical scheme: a variable stiffness continuum robot, comprising a driving seat, a first center hole is formed in the middle part of the driving seat, a spring chuck is installed inside the first center hole, a conical part is arranged on the top of the spring chuck, a notch is formed on the side wall of the conical part, and a first conical surface matched with the conical part is arranged on the inner side wall of the first center hole close to the bottom;

[0007] One end of the spring chuck away from the conical part is threaded out from the end of the driving seat and is screwed with a locking nut;

[0008] The elastic rod is detachably mounted on the spring chuck, a driving unit is arranged on the side wall of the driving seat, a ball socket unit is pivotally connected to the driving unit, a steering ball unit is pivotally connected to the other side of the ball socket unit, the number of the steering ball unit and the ball socket unit is multiple, and the steering ball unit and the ball socket unit are alternately arranged;

[0009] One end of the ball socket unit is pivotally connected to a terminal seat unit, the elastic rod penetrates the steering ball unit and the ball socket unit, and the tail end of the elastic rod is detachably mounted on the terminal seat unit;

[0010] A plurality of driving ropes are fixedly connected to the terminal seat unit, the plurality of driving ropes are arranged in a circumferential direction, and the plurality of driving ropes penetrate the steering ball unit, the ball socket unit, the driving unit and the driving seat.

[0011] Further, the driving unit comprises a first cylinder fixedly connected to the center of the driving seat, the first cylinder is hollow, and the first cylinder and the first center hole are in communication with each other, and the elastic rod penetrates the first cylinder and the first center hole;

[0012] The outer surface of the first cylinder is sleeved with a thin film air bag assembly, the outer surface of the first cylinder is slidably connected with a movable plate, and the thin film air bag assembly is located between the movable plate and the driving seat;

[0013] A first hemispherical protrusion is arranged on the outer side of the movable plate, an inner friction layer and an outer friction layer are fixedly connected to the side wall of the movable plate, the inner friction layer is located between the outer friction layer and the first hemispherical protrusion, and the inner friction layer and the outer friction layer are spherical, and the centers of the inner friction layer, the outer friction layer and the first hemispherical protrusion coincide;

[0014] An inner unloading groove is formed in the side wall of the inner friction layer, an outer unloading groove is formed in the side wall of the outer friction layer, a cross ball ring is slidably connected to the side wall of the outer friction layer, an inner sliding table is fixedly connected to the inner spherical surface of the cross ball ring, and an outer sliding table is fixedly connected to the outer spherical surface, the cross ball ring is attached to the outer surface of the outer friction layer, and an outer sliding groove is formed in the outer side wall of the outer friction layer and matched with the inner sliding table.

[0015] Further, the thin film air bag assembly is formed by stacking multiple thin film air bags, and is in the shape of a bellows, air holes are formed in the multiple thin film air bags, adjacent thin film air bags are in communication with each other through the air holes, and an air pipe is penetratingly arranged on the side wall of the driving seat and in communication with the air holes.

[0016] Further, the ball socket unit comprises a double ball socket sleeve, ball sockets are formed at both ends of the double ball socket sleeve, and ball socket grooves are arranged in the ball sockets;

[0017] The second center hole is symmetrically provided with two guide rings at both ends, the inner and outer surfaces of the guide rings are concentric spherical surfaces, and the two guide rings are concentric with the ball sockets at both ends of the double ball socket sleeve;

[0018] The second cylindrical body is fixedly connected to the side wall of the guide ring and is installed in the second center hole, the second cylindrical body is hollow, and the second cylindrical body is penetrated by the elastic rod and the second center hole;

[0019] The ball socket provided at both ends of the double ball socket sleeve is provided with a medium friction layer between the ball socket and the guide ring, the inner and outer surfaces of the medium friction layer are concentric spherical surfaces, the medium friction layer is concentric with the ball socket, and the medium friction layer is sleeved on the second cylindrical body.

[0020] Further, when the driving unit is rotationally connected with the ball socket unit, the first half-spherical protrusion on the end surface of the movable plate, the guide ring, the inner friction layer, the medium friction layer, the outer friction layer and the cross ball ring are sequentially connected and concentrically arranged;

[0021] The outer sliding table outside the cross ball ring in the driving unit is embedded in the ball socket groove of the double ball socket sleeve and slides along the ball socket groove.

[0022] Further, the steering ball unit comprises an articulation ball, two second half-spherical protrusions are arranged on both sides of the articulation ball, and the two second half-spherical protrusions are concentric, guide holes are formed at the top ends of the two second half-spherical protrusions, and the elastic rod penetrates the guide holes of the articulation ball;

[0023] The inner friction layer and the outer friction layer are fixedly connected to both sides of the articulation ball, the inner friction layer is located between the outer friction layer and the second half-spherical protrusion, and the outer friction layer, the inner friction layer and the second half-spherical protrusion are concentrically arranged;

[0024] The outer sliding table outside the cross ball ring is also slidingly connected to the outer friction layer.

[0025] Further, when the steering ball unit is rotationally connected with the adjacent ball socket unit, the second half-spherical protrusion on the articulation ball, the guide ring, the inner friction layer, the medium friction layer, the outer friction layer and the cross ball ring are sequentially connected and concentrically arranged;

[0026] The outer sliding table outside the cross ball ring in the steering ball unit is embedded in the ball socket groove of the double ball socket sleeve and can slide along the ball socket groove.

[0027] Further, the terminal seat unit comprises a terminal plate fixed at one end of the driving rope, a terminal hemisphere is fixedly connected to the side wall of the terminal plate, a third center hole is formed in the center position of the terminal plate and the terminal hemisphere, a spring chuck is installed in the third center hole, a second conical surface matched with the conical part of the spring chuck is arranged in the third center hole, and the tail end of the elastic rod is connected in the spring chuck;

[0028] The end away from the conical part of the spring chuck is threadedly connected with a locking nut, and the locking nut is located in the third center hole of the terminal hemisphere;

[0029] The side wall of the terminal plate is fixedly connected with an inner friction layer and an outer friction layer, the inner friction layer is located between the outer friction layer and the terminal hemisphere, and the outer friction layer, the inner friction layer and the terminal hemisphere are concentrically arranged;

[0030] The outer side wall of the outer friction layer is also slidably connected with a cross ball ring.

[0031] Further, when the terminal seat unit is rotationally connected with the adjacent ball socket unit, the terminal hemisphere, the guide ring, the inner friction layer, the middle friction layer, the outer friction layer and the cross ball ring are sequentially connected and concentrically arranged;

[0032] The outer slide platform outside the cross ball ring in the terminal seat unit is embedded in the ball socket groove of the double ball socket sleeve and can slide along the ball socket groove.

[0033] Further, a pin hole is formed in the driving seat, a limited rotation pin is fixedly connected in the pin hole, and the other end of the limited rotation pin is slidably connected in the movable plate.

[0034] The present application has at least the following advantages:

[0035] 1. The cross ball ring is added between the adjacent series connection units, the inner and outer spherical surfaces of the cross are provided with an inner slide platform and an outer slide platform, respectively, and the two slide platforms are perpendicular to each other in the projection plane, the torsion between the adjacent series connection assemblies is limited by matching the two groups of slide platforms with the outer slide groove and the ball socket groove, and thus the torsional freedom degree of the whole continuum robot is limited, so that the robot has high torsional stiffness.

[0036] 2. The inner friction layer, the middle friction layer and the outer friction layer structure are arranged, the inflation and expansion of the thin film air bag are used to extrude each friction layer, the friction between the adjacent units is increased under the friction, the adjacent series connection units have large friction locking torque, and thus the bending stiffness of the whole continuum robot can be changed in a large range.

[0037] 3. The application adopts multi-layer film air bag superposition to extrude the friction layer. Because the film air bag has small internal space and large cross-sectional area, the air bag has fast inflation and deflation speed. Compared with the existing air bag which changes the structural stiffness by filling particles, the continuum robot of the application has large range stiffness change ability and high stiffness change speed.

[0038] Of course, it is not necessary for any embodiment of the application to achieve all the advantages mentioned above. BRIEF DESCRIPTION OF DRAWINGS

[0039] Fig. 1 is a cross-sectional view of the overall structure of the application;

[0040] Fig. 2 is a cross-sectional view of the structure of the driving unit in the application;

[0041] Fig. 3 is a cross-sectional view of the structure of the driving unit A-A in the application;

[0042] Fig. 4 is a perspective view of the film air bag assembly in the application;

[0043] Fig. 5 is a perspective view of the internal friction layer structure in the application;

[0044] Fig. 6 is a perspective view of the external friction layer structure in the application;

[0045] Fig. 7 is a perspective view of the cross ball ring structure in the application;

[0046] Fig. 8 is a cross-sectional view of the ball socket unit in the application;

[0047] Fig. 9 is a perspective view of the double ball socket sleeve structure in the application;

[0048] Fig. 10 is a cross-sectional view of the steering ball unit in the application;

[0049] Fig. 11 is a cross-sectional view of the end seat unit in the application;

[0050] Fig. 12 is a perspective view of the overall structure of the application.

[0051] The figure mark: 1, drive seat;11, drive unit;111, first taper;112, through hole;113, first center hole;114, first cylinder;12, spring chuck;121, notch;122, tapered portion;13, locking nut;14, film air bag assembly;141, film air bag;1411, air hole;15, movable plate;151, first half ball protrusion;16, inner friction layer;161, inner layer protrusion;162, inner unloading groove;17, outer friction layer;171, outer layer sliding groove;172, outer unloading groove;173, outer layer protrusion;18, cross ball ring;181, inner sliding table;182, outer sliding table;19, limit rotation pin;20, air pipe;2, elastic rod;3, drive cable;4, ball socket unit;41, double ball socket sleeve;411, ball socket;412, ball socket groove;413, second center hole;42, middle friction layer;43, guide ring;44, second cylinder;5, steering ball unit;51, joint ball;511, second half ball protrusion;512, guide hole;6, end seat unit;61, end plate;611, third center hole;612, second taper;62, end hemisphere. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative labor belong to the scope of protection of the present disclosure.

[0053] Please refer to FIG. 1-12, the present application provides a technical solution: a variable stiffness continuum robot, comprising a drive seat 1, the middle part of the drive seat 1 is provided with a first center hole 113, the inside of the first center hole 113 is installed with a spring chuck 12, the top of the spring chuck 12 is provided with a tapered portion 122, and the inner side wall of the first center hole 113 close to the bottom is provided with a first taper 111 matched with the tapered portion 122;

[0054] As shown in FIG. 3, the spring chuck 12 is detachably installed with an elastic rod 2, one end of the spring chuck 12 away from the tapered portion 122 is threaded connected with a locking nut 13 from the end of the drive seat 1, and the center of the spring chuck 12 is provided with a through hole 112, the sidewall of the tapered portion 122 is provided with a notch 121, therefore, by rotating the locking nut 13, the tapered portion 122 is squeezed to press the first taper 111, under the constraint of the first taper 111, the conical portion of the spring chuck 12 can be slightly elastically deformed, so that the notch 121 gradually becomes smaller, thereby being able to clamp the elastic rod 2 in the through hole 112 of the spring chuck 12, by using the set elastic rod 2, mainly can play the role of connection and deformation, as shown in FIG. 10.

[0055] The side wall of the driving seat 1 is provided with a driving unit 11, and the driving unit 11 is connected with a ball socket unit 4 in a deflectable manner. The other side of the ball socket unit 4 is rotatably connected with a steering ball unit 5. The number of the steering ball unit 5 and the ball socket unit 4 is both multiple, and the steering ball unit 5 and the ball socket unit 4 are alternately arranged.

[0056] One end of the ball socket unit 4 is rotatably connected with a terminal seat unit 6. The elastic rod 2 penetrates the steering ball unit 5 and the ball socket unit 4, and the tail end of the elastic rod 2 is detachably installed on the terminal seat unit 6.

[0057] The terminal seat unit 6 is fixedly connected with a plurality of driving cables 3. The plurality of driving cables 3 are arranged in a circumferential direction, and the plurality of driving cables 3 penetrate the steering ball unit 5, the ball socket unit 4, the driving unit 11 and the driving seat 1.

[0058] According to the technical scheme of the embodiment, the driving unit 11 includes a first cylinder 114 fixedly connected at the center position of the driving seat 1. The first cylinder 114 is hollow inside and penetrates the first center hole 113. The first cylinder 114 is integrally formed with the driving seat 1. The elastic rod 2 penetrates the first cylinder 114 and the first center hole 113.

[0059] The outer surface of the first cylinder 114 is sleeved with a thin film air bag assembly 14. The outer surface of the first cylinder 114 is slidably connected with a movable plate 15. The thin film air bag assembly 14 is located between the movable plate 15 and the driving seat 1. The movable plate 15 can slide along the axis direction of the first cylinder 114.

[0060] The outer side of the movable plate 15 is provided with a first hemispherical protrusion 151. The side wall of the movable plate 15 is fixedly connected with an inner friction layer 16 and an outer friction layer 17. The inner friction layer 16 is located between the outer friction layer 17 and the first hemispherical protrusion 151. The inner friction layer 16 and the outer friction layer 17 are both provided in a spherical shape. The centers of the inner friction layer 16, the outer friction layer 17 and the first hemispherical protrusion 151 coincide.

[0061] As shown in FIGS. 5-7, the side wall of the inner friction layer 16 is provided with an inner unloading groove 162. The side wall of the outer friction layer 17 is provided with an outer unloading groove 172. The side wall of the outer friction layer 17 is slidably connected with a cross ball ring 18. The inner spherical surface of the cross ball ring 18 is fixedly connected with an inner sliding table 181. The outer spherical surface is fixedly connected with an outer sliding table 182. The projections of the inner sliding table 181 and the outer sliding table 182 on the plane formed by the end ring of the cross ball ring 18 are perpendicular to each other. The cross ball ring 18 is attached to the outer surface of the outer friction layer 17. The outer side wall of the outer friction layer 17 is provided with an outer layer sliding groove 171 matched with the inner sliding table 181.

[0062] It needs to be explained that the driving seat 1 is provided with a pin hole, the pin hole is fixedly connected with a limit pin 19, the other end of the limit pin 19 is slidably connected in the movable plate 15, the limit pin 19 penetrates the movable plate 15, when the movable plate 15 slides up and down along the first cylinder 114, the limit pin 19 can provide limiting and guiding for the movable plate 15, and prevent the movable plate 15 from rotating.

[0063] Further, as shown in FIG. 2 and FIG. 4, the film air bag assembly 14 is stacked by multiple film air bags 141, and is provided as a bellows, the inside of the multiple film air bags 141 is provided with air holes 1411, adjacent film air bags 141 are penetrated by the air holes 1411, and the sidewall of the driving seat 1 is provided with a gas pipe 20 penetratingly installed, the gas pipe 20 is connected with the air holes 1411, and by introducing compressed gas into the gas pipe 20, the film air bag assembly 14 is inflated to expand, so as to press the movable plate 15 to slide along the axis direction of the first cylinder 114.

[0064] Further, as shown in FIG. 5-6, the end of the inner friction layer 16 is provided with multiple inner layer protrusions 161, the end of the outer friction layer 17 is provided with multiple outer layer protrusions 173, and the sidewall of the movable plate 15 is provided with grooves matched with the inner layer protrusions 161 and the outer layer protrusions 173, by embedding the inner layer protrusions 161 and the outer layer protrusions 173 in the grooves, the inner friction layer 16 and the outer friction layer 17 can be fixed on the movable plate 15.

[0065] For the technical scheme of the embodiment, as shown in FIG. 8-9, the ball socket unit 4 includes a double ball socket sleeve 41, the two ends of the double ball socket sleeve 41 are provided with ball sockets 411, the inside of the ball socket 411 is provided with a ball socket groove 412;

[0066] The center of the double ball socket sleeve 41 is provided with a second center hole 413, the second center hole 413 is penetrated by the ball socket groove 412, the two ends of the second center hole 413 are symmetrically provided with two guide rings 43, the inner and outer surfaces of the two guide rings 43 are concentric spherical surfaces, and the two guide rings 43 are concentric with the ball sockets 411 at the two ends of the double ball socket sleeve 41 respectively;

[0067] The sidewall of the guide ring 43 is fixedly connected with a second cylinder 44, the second cylinder 44 is installed in the second center hole 413 and can slide in the second center hole 413, the inside of the second cylinder 44 is hollow, and the second cylinder 44 is penetrated by the guide ring 43, the second cylinder 44 and the guide ring 43 are integrally formed, and the elastic rod 2 penetrates the second cylinder 44 and the second center hole 413;

[0068] The middle friction layer 42 is arranged between the ball socket 411 and the guide ring 43, and the inner and outer surfaces of the middle friction layer 42 are concentric spherical surfaces, the middle friction layer 42 is concentric with the ball socket 411, and the middle friction layer 42 is sleeved on the second cylinder 44.

[0069] Specifically, when the driving unit 11 is rotationally connected with the ball socket unit 4, the first half-spherical protrusion 151, the guide ring 43, the inner friction layer 16, the middle friction layer 42, the outer friction layer 17 and the cross ball ring 18 are sequentially connected and concentrically arranged on the end surface of the movable plate 15, and the outer slide table 182 outside the cross ball ring 18 in the driving unit 11 is embedded in the ball socket groove 412 of the double ball socket sleeve 41, at this time, the guide ring 43 can relatively slide between the first half-spherical protrusion 151 and the inner friction layer 16, the middle friction layer 42 can relatively slide between the inner friction layer 16 and the outer friction layer 17, and the outer slide table 182 can relatively slide along the ball socket groove 412, so that the ball socket unit 4 can be deflected around the driving unit 11, so as to realize steering, and the inner slide table 181, the outer slide table 182, the outer layer slide groove 171 and the ball socket groove 412 are matched, so as to limit the torsion between the driving unit 11 and the ball socket unit 4, and avoid that the torsion freedom is too large.

[0070] For the technical scheme of the embodiment, as shown in FIG. 10, the steering ball unit 5 includes an articulating ball 51, two second half-spherical protrusions 511 are arranged on both sides of the articulating ball 51, and the two second half-spherical protrusions 511 are concentric, a guide hole 512 is arranged at the top end of each of the two second half-spherical protrusions 511, and the elastic rod 2 penetrates the guide hole 512 of the articulating ball 51.

[0071] The articulating ball 51 is fixedly connected with the inner friction layer 16 and the outer friction layer 17 respectively on both sides, the inner friction layer 16 is located between the outer friction layer 17 and the second half-spherical protrusion 511, and the outer friction layer 17, the inner friction layer 16 and the second half-spherical protrusion 511 are concentrically arranged.

[0072] The outer side wall of the outer friction layer 17 is also slidingly connected with the cross ball ring 18, and the inner and outer spherical surfaces of the cross ball ring 18 are fixedly connected with the inner slide table 181 and the outer slide table 182 respectively.

[0073] It should be noted that the fixing mode between the inner friction layer 16, the outer friction layer 17 and the articulating ball 51 is the same as the fixing mode between the movable plate 15.

[0074] Specifically, when the steering ball unit 5 is rotationally connected with the adjacent ball socket unit 4, the second hemispherical protrusion 511 on the joint ball 51, the guide ring 43, the inner friction layer 16, the middle friction layer 42, the outer friction layer 17 and the cross ball ring 18 are sequentially connected and concentrically arranged, the outer sliding platform 182 outside the cross ball ring 18 in the steering ball unit 5 is embedded in the ball socket groove 412 of the double ball socket sleeve 41, at this time, the guide ring 43 can relatively slide between the second hemispherical protrusion 511 and the inner friction layer 16, the middle friction layer 42 can relatively slide between the inner friction layer 16 and the outer friction layer 17, and the outer sliding platform 182 can relatively slide along the ball socket groove 412, so that the steering ball unit 5 can be deflected around the ball socket unit 4, so as to realize steering, and by cooperation of the inner sliding platform 181, the outer sliding platform 182, the outer layer sliding groove 171 and the ball socket groove 412, the torsion between the steering ball unit 5 and the ball socket unit 4 can be limited, so as to avoid excessive torsion freedom.

[0075] According to the technical scheme of the embodiment, as shown in FIG. 11, the terminal seat unit 6 includes a terminal plate 61 fixed at one end of the driving cable 3, a terminal hemispherical shell 62 fixedly connected to the side wall of the terminal plate 61, a third central hole 611 formed in the center position of the terminal plate 61 and the terminal hemispherical shell 62, a spring collet 12 installed in the third central hole 611, a second taper surface 612 provided in the third central hole 611 and matched with the taper portion 122 of the spring collet 12, and the tail end of the elastic rod 2 connected in the spring collet 12.

[0076] A locking nut 13 is threadedly connected to the end of the spring collet 12 away from the taper portion 122, and the locking nut 13 is located in the third central hole 611 of the terminal hemispherical shell 62. Under the limiting action of the second taper surface 612, the taper portion 122 of the spring collet 12 is deformed by tightening the locking nut 13, so that the tail end of the elastic rod 2 is fixed on the spring collet 12, thereby realizing the fixation of the tail end of the elastic rod 2 on the terminal plate 61.

[0077] The inner friction layer 16 and the outer friction layer 17 are fixedly connected to the side wall of the terminal plate 61, the inner friction layer 16 is located between the outer friction layer 17 and the terminal hemispherical shell 62, and the outer friction layer 17, the inner friction layer 16 and the terminal hemispherical shell 62 are concentrically arranged.

[0078] The outer side wall of the outer friction layer 17 is also slidingly connected with the cross ball ring 18, and the inner and outer spherical surfaces of the cross ball ring 18 are fixedly connected with the inner sliding platform 181 and the outer sliding platform 182, respectively.

[0079] Specifically, when the terminal seat unit 6 is rotationally connected with the adjacent ball socket unit 4, the terminal hemisphere 62, the guide ring 43, the inner friction layer 16, the middle friction layer 42, the outer friction layer 17 and the cross ball ring 18 are sequentially connected and concentrically arranged, the outer sliding platform 182 outside the cross ball ring 18 in the terminal seat unit 6 is embedded in the ball socket groove 412 of the double ball socket sleeve 41, at this time, the guide ring 43 can relatively slide between the terminal hemisphere 62 and the inner friction layer 16, the middle friction layer 42 can relatively slide between the inner friction layer 16 and the outer friction layer 17, and the outer sliding platform 182 can relatively slide along the ball socket groove 412, so that the terminal seat unit 6 can be deflected around the ball socket unit 4, so as to realize steering, and by cooperation of the inner sliding platform 181, the outer sliding platform 182, the outer layer sliding groove 171 and the ball socket groove 412, the torsion between the terminal seat unit 6 and the ball socket unit 4 can be limited, so as to avoid that the torsion freedom is too large.

[0080] For the technical scheme of the embodiment, as shown in FIG. 12, the number of driving ropes 3 is set to three, the three driving ropes 3 are fixed on the terminal plate 61 of the terminal seat unit 6, the three driving ropes 3 are circumferentially arranged along the terminal plate 61, and the adjacent driving ropes 3 are equally spaced, the joint ball 51 and the side wall of the driving seat 1 are both provided with through holes 112 for penetrating the driving ropes 3, and it should be noted that the free end of the driving rope 3 penetrating from the driving seat 1 is connected with an external traction device, which can be set as a hydraulic rod, a traction machine or the like, which is not limited here and can be selected according to the actual situation.

[0081] The use method and process of the application:

[0082] As shown in FIG. 12, when bending is needed, the driving rope 3 in the bending direction is retracted by the external traction device, and the remaining driving ropes 3 are appropriately loosened to avoid interference, at this time, by making the driving ropes 3 produce non-equal length displacement, the relative rotation between the terminal plate 61 unit, the steering ball unit 5 and the ball socket unit 4 can be generated, so as to realize the bending of the whole robot, and the functions of steering, obstacle avoidance and the like can be realized.

[0083] When the film air bag 141 group is not filled with compressed gas, the movable plate 15 can slide freely along the first cylinder 114 axis direction, at this time the robot is in a flexible state, can freely bend, when the stiffness of the whole robot needs to be adjusted, first fill the compressed gas into the air pipe 20 by means of the external inflation pump, the film air bag assembly 14 will be inflated and expanded, so as to extrude the movable plate 15 to slide along the first cylinder 114 axis direction, because the elastic rod 2 is fixed at the end plate 61 and the driving seat 1 respectively, so the total length of the robot will be constrained, at this time the movable plate 15 will first extrude the ball socket unit 4 after sliding, and extrude the steering head unit, end plate 61 unit through the ball socket unit 4, so that the internal friction layer 16, the middle friction layer 42, the outer friction layer 17, the cross ball ring 18 and other structures between the units are compressed to form a whole, so as to enhance the friction between the units, at this time the whole robot will change from flexible state to rigid state, and by adjusting the inflation size of the film air bag assembly 14, the friction between the units can be controlled, so as to control the stiffness of the robot, so as to facilitate the adaptive adjustment of the stiffness of the robot according to the actual situation, and further improve the practicability.

[0084] It is to be understood that the terminology used herein such as first and second, and the like, is only used to distinguish one entity or action from another entity or action, and does not necessarily require or imply that there is any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, so that a process, method, article, or apparatus that includes a list of elements does not only include those elements, but also includes other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0085] For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances. When an element is referred to as "assembled", "mounted", "fixed" or "disposed" on another element, it can be directly on another element or there can be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes, and are not the only implementation.

[0086] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

[0087] In the description of the disclosure, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the disclosure. In the description of the disclosure, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

Claims

1. A variable stiffness continuum robot, comprising a drive base (1), characterized in that, The drive seat (1) has a first central hole (113) in the middle. A spring collet (12) is installed inside the first central hole (113). The top of the spring collet (12) is provided with a tapered part (122), and a notch (121) is provided on the side wall of the tapered part (122). The inner side wall of the first central hole (113) near the bottom is provided with a first conical surface (111) that matches the tapered part (122). The spring collet (12) is detachably mounted with an elastic rod (2), and the end of the spring collet (12) away from the tapered part (122) extends out from the end of the drive seat (1) and is threadedly connected with a locking nut (13); A drive unit (11) is provided on the side wall of the drive seat (1). A ball socket unit (4) is rotatably connected to the drive unit (11). A steering ball unit (5) is rotatably connected to the other side of the ball socket unit (4). The number of steering ball units (5) and ball socket units (4) is set to multiple, and the steering ball units (5) and ball socket units (4) are arranged alternately. One end of the ball socket unit (4) is rotatably connected to the end seat unit (6), the elastic rod (2) passes through the steering ball unit (5) and the ball socket unit (4), and the tail end of the elastic rod (2) is detachably installed on the end seat unit (6); Multiple drive cables (3) are fixedly connected to the end seat unit (6). The multiple drive cables (3) are arranged in a circumferential manner, and all of the multiple drive cables (3) pass through the steering ball unit (5), the drive unit (11) and the drive seat (1).

2. The variable stiffness continuum robot according to claim 1, characterized in that: The drive unit (11) includes a first cylinder (114) fixedly connected to the center of the drive seat (1). The first cylinder (114) is hollow inside and communicates with the first central hole (113). An elastic rod (2) is arranged through the first cylinder (114) and the first central hole (113). The outer surface of the first cylinder (114) is fitted with a thin film airbag (141) assembly (14), and a movable plate (15) is slidably connected to the outer surface of the first cylinder (114), and the thin film airbag (141) assembly (14) is located between the movable plate (15) and the drive seat (1). The movable plate (15) has a first hemispherical protrusion (151) on its outer side. An inner friction layer (16) and an outer friction layer (17) are fixedly connected to the side wall of the movable plate (15). The inner friction layer (16) is located between the outer friction layer (17) and the first hemispherical protrusion (151). Both the inner friction layer (16) and the outer friction layer (17) are spherical. The spherical surfaces of the inner friction layer (16), the outer friction layer (17) and the first hemispherical protrusion (151) are spherical. Hearts coincide; The inner friction layer (16) has an inner unloading groove (162) on its sidewall, and the outer friction layer (17) has an outer unloading groove (172) on its sidewall. A cross ball ring (18) is slidably connected to the sidewall of the outer friction layer (17). An inner slide (181) is fixedly connected to the inner spherical surface of the cross ball ring (18), and an outer slide (182) is fixedly connected to the outer spherical surface. The cross ball ring (18) is attached to the outer surface of the outer friction layer (17), and an outer slide groove (171) that matches the inner slide (181) is provided on the outer sidewall of the outer friction layer (17).

3. A variable stiffness continuum robot according to claim 2, characterized in that: The thin film airbag (141) assembly (14) is made of multiple layers of thin film airbags (141) stacked together, and the whole is set in a corrugated tube shape. Each layer of thin film airbags (141) has an air hole (1411) inside. Adjacent thin film airbags (141) are interconnected through the air hole (1411), and an air tube (20) is installed through the side wall of the drive seat (1). The air tube (20) is connected to the air hole (1411).

4. A variable stiffness continuum robot according to claim 2, characterized in that: The ball socket unit (4) includes a double ball socket sleeve (41), with ball sockets (411) at both ends of the double ball socket sleeve (41), and ball socket grooves (412) inside the ball sockets (411); The double ball socket (41) has a second central hole (413) at its center. Two guide rings (43) are symmetrically arranged at both ends of the second central hole (413). The inner and outer surfaces of the guide rings (43) are concentric spherical surfaces, and the two guide rings (43) are concentric with the ball sockets (411) at both ends of the double ball socket (41). A second cylinder (44) is fixedly connected to the side wall of the guide ring (43). The second cylinder (44) is installed in the second central hole (413). The interior of the second cylinder (44) is hollow, and the second cylinder (44) and the guide ring (43) are connected. The elastic rod (2) passes through the second cylinder (44) and the second central hole (413). A middle friction layer (42) is provided between the ball sockets (411) at both ends of the double ball socket sleeve (41) and the guide ring (43). The inner and outer surfaces of the middle friction layer (42) are concentric spherical surfaces. The middle friction layer (42) is concentric with the ball sockets (411) and is sleeved on the second cylinder (44).

5. A variable stiffness continuum robot according to claim 4, characterized in that: When the drive unit (11) is rotatably connected to the ball socket unit (4), the first hemispherical protrusion (151), guide ring (43), inner friction layer (16), middle friction layer (42), outer friction layer (17) and cross ball ring (18) on the end face of the movable plate (15) are connected in sequence and arranged concentrically. The outer slide (182) of the cross ball ring (18) in the drive unit (11) is embedded in the ball groove (412) of the double ball sleeve (41) and slides along the ball groove (412).

6. A variable stiffness continuum robot according to claim 5, characterized in that: The steering ball unit (5) includes a joint ball (51). The joint ball (51) has two second hemispherical protrusions (511) on both sides, and the two second hemispherical protrusions (511) are concentric. The top of each of the two second hemispherical protrusions (511) is provided with a guide hole (512). The elastic rod (2) passes through the guide hole (512) of the joint ball (51). The articulated ball (51) is fixedly connected to an inner friction layer (16) and an outer friction layer (17) on both sides respectively. The inner friction layer (16) is located between the outer friction layer (17) and the second hemisphere protrusion (511), and the outer friction layer (17), the inner friction layer (16), and the second hemisphere protrusion (511) are arranged concentrically. The outer wall of the outer friction layer (17) is also slidably connected with a cross ball ring (18).

7. A variable stiffness continuum robot according to claim 6, characterized in that: When the steering ball unit (5) is rotatably connected to the adjacent ball socket unit (4), the second hemispherical protrusion (511), guide ring (43), inner friction layer (16), middle friction layer (42), outer friction layer (17) and cross ball ring (18) on the joint ball (51) are connected in sequence and arranged concentrically. The outer slide (182) of the cross ball ring (18) in the steering ball unit (5) is embedded in the ball groove (412) of the double ball sleeve (41) and can slide along the ball groove (412).

8. A variable stiffness continuum robot according to claim 7, characterized in that: The end seat unit (6) includes an end plate (61) fixed to one end of the drive cable (3). An end hemisphere (62) is fixedly connected to the side wall of the end plate (61). A third center hole (611) is provided at the center of the end plate (61) and the end hemisphere (62). A spring collet (12) is installed in the third center hole (611). A second conical surface (612) adapted to the conical part (122) of the spring collet (12) is provided in the third center hole (611). The tail end of the elastic rod (2) is connected in the spring collet (12). The spring collet (12) is threaded with a locking nut (13) at one end away from the tapered portion (122), and the locking nut (13) is located in the third center hole (611) of the end hemisphere (62); An inner friction layer (16) and an outer friction layer (17) are fixedly connected to the side wall of the end plate (61). The inner friction layer (16) is located between the outer friction layer (17) and the end hemisphere (62), and the outer friction layer (17), the inner friction layer (16), and the end hemisphere (62) are arranged concentrically. The outer wall of the outer friction layer (17) is also slidably connected with a cross ball ring (18).

9. A variable stiffness continuum robot according to claim 8, characterized in that: When the end seat unit (6) is rotatably connected to the adjacent ball socket unit (4), the end hemisphere (62), guide ring (43), inner friction layer (16), middle friction layer (42), outer friction layer (17) and cross ball ring (18) are connected in sequence and arranged concentrically. The outer slide (182) of the cross ball ring (18) in the end seat unit (6) is embedded in the ball groove (412) of the double ball socket sleeve (41) and can slide along the ball groove (412).

10. A variable stiffness continuum robot according to claim 9, characterized in that: The drive seat (1) has a pin hole, and a limiting pin (19) is fixedly connected inside the pin hole. The other end of the limiting pin (19) is slidably connected in the movable plate (15).

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