A variable stiffness continuum robot

Abstract

The present invention discloses a variable stiffness continuum robot, and relates to the technical field of soft robots. The present invention comprises a driving seat, a first central hole is provided in the middle of the driving seat, a spring chuck is installed inside the first central hole; a driving unit is provided on the side wall of the driving seat, a ball and socket unit is rotatably connected to the driving unit, a steering ball unit is rotatably connected to the other side of the ball and socket unit, and the steering ball unit and the ball and socket unit are arranged alternately; one end of the ball and socket unit is rotatably connected to the end seat unit, and the elastic rod passes through the steering ball unit and the ball and socket unit. The present invention arranges an inner friction layer, a middle friction layer and an outer friction layer structure, and uses the inflation of a thin film airbag to squeeze each friction layer. Under the action of friction, the friction force between adjacent units increases, so that there is a large friction locking torque between adjacent series units, thereby the bending stiffness of the entire continuum robot can be changed in a large range.

Description

Technical Field

[0001] The invention relates to the technical field of soft robots, in particular to a variable stiffness continuum robot. Background Art

[0002] There are a large number of thermal vessels, pipelines (long-distance, industrial and gas) and other narrow equipment spaces, boiler inner walls, pressure vessels (heat exchangers, complete sets of equipment), and small-diameter equipment in energy and petrochemical pressure equipment. It is difficult to achieve efficient and reliable automated non-destructive testing and flaw detection maintenance, which can easily lead to missed detection of dangerous hidden dangers and cause catastrophic accidents. Therefore, achieving efficient and reliable intelligent non-destructive testing and flaw detection maintenance in dangerous and special narrow space environments has become a hot and difficult issue in the industry.

[0003] To solve the above problems, continuum robots are often used in the prior art for non-destructive testing. Due to their own bendability, continuum robots can be compatible with the contact object and greatly reduce contact stress through continuous deformation. They have higher flexibility, safety and adaptability, and have unique advantages in minimally invasive surgery, disaster search and rescue, fragile object grasping, and operations in narrow spaces and multi-obstacle environments. However, since continuum robots usually have low stiffness, their load-bearing capacity is poor. Although variable stiffness structures represented by blocking structures have solved the problem of low stiffness of continuum robots to a certain extent, there are still problems such as limited stiffness change range and slow stiffness change. For this reason, we propose a variable stiffness continuum robot. Summary of the invention

[0004] The object of the present invention is to provide a variable stiffness continuum robot, which can realize friction locking of adjacent units by squeezing each friction layer through airbags, thereby changing the bending stiffness of the robot and improving its load-bearing capacity.

[0005] To achieve the above object, the present invention provides the following technical solution: a variable stiffness continuum robot, comprising a driving seat, a first central hole is provided in the middle of the driving seat, a spring chuck is installed inside the first central hole, a conical portion is provided on the top of the spring chuck, a notch is provided on the side wall of the conical portion, and a first conical surface matching the conical portion is provided on the inner side wall of the first central hole near the bottom;

[0006] One end of the spring chuck away from the conical portion passes through the end of the driving seat and is threadedly connected with a locking nut;

[0007] The spring chuck is detachably mounted with an elastic rod, the side wall of the driving seat is provided with a driving unit, the driving unit is rotatably connected with a ball and socket unit, the other side of the ball and socket unit is rotatably connected with a steering ball unit, the number of the steering ball units and the ball and socket units are both set to multiple, and the steering ball units and the ball and socket units are arranged alternately;

[0008] One end of the ball and socket unit is rotatably connected to the end seat unit, the elastic rod penetrates the steering ball unit and the ball and socket unit, and the tail end of the elastic rod is detachably mounted on the end seat unit;

[0009] The end seat unit is fixedly connected with a plurality of driving cables, which are arranged circumferentially as a whole, and all of the driving cables pass through the steering ball unit, the ball socket unit, the driving unit and the driving seat.

[0010] Furthermore, the driving unit comprises a first cylinder fixedly connected to the center of the driving seat, the first cylinder is hollow inside and is connected to the first center hole, and the elastic rod is arranged through the first cylinder and the first center hole;

[0011] The outer surface of the first cylinder is sleeved with a film airbag assembly, the outer surface of the first cylinder is slidably connected with a movable plate, and the film airbag assembly is located between the movable plate and the driving seat;

[0012] 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 both arranged in a spherical shape, and the inner friction layer and the outer friction layer coincide with the center of the first hemispherical protrusion;

[0013] An inner unloading groove is provided on the side wall of the inner friction layer, an outer unloading groove is provided on the side wall of the outer friction layer, and 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 matched with the inner sliding table is provided on the outer side wall of the outer friction layer.

[0014] Furthermore, the film airbag assembly is formed by stacking multiple layers of film airbags, which are overall configured in a bellows shape. The interiors of the multiple layers of film airbags are all provided with air holes, and adjacent film airbags are interconnected through the air holes. An air pipe is installed through the side wall of the driving seat, and the air pipe is connected to the air holes.

[0015] Furthermore, the ball and socket unit comprises a double ball and socket sleeve, both ends of the double ball and socket sleeve are provided with ball sockets, and the inside of the ball socket is provided with a ball socket groove;

[0016] A second center hole is opened at the center of the double ball-and-socket sleeve, and two guide rings are symmetrically arranged at both ends of the second center hole. The inner and outer surfaces of the guide rings are concentric spherical surfaces, and the two guide rings are respectively concentric with the ball sockets at both ends of the double ball-and-socket sleeve;

[0017] A second cylinder is fixedly connected to the side wall of the guide ring. The second cylinder is installed in the second center hole. The interior of the second cylinder is hollow, and the second cylinder and the guide ring are connected. The elastic rod passes through the second cylinder and the second center hole.

[0018] A middle friction layer is arranged between the ball sockets opened at both ends of the double ball socket sleeve and the guide ring. The inner and outer surfaces of the middle friction layer are both concentric spherical surfaces. The middle friction layer is concentric with the ball sockets and is sleeved on the second cylinder.

[0019] Furthermore, when the driving unit is rotatably connected to the ball-and-socket unit, the first hemispherical protrusion, the guide ring, the inner friction layer, the middle friction layer, the outer friction layer and the cross ball ring on the end surface of the movable plate are sequentially connected and concentrically arranged;

[0020] The outer sliding platform on the outer side of 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.

[0021] Further, the steering ball unit comprises a joint ball, two second hemispherical protrusions are arranged on both sides of the joint ball, and the two second hemispherical protrusions are concentric, and the tops of the two second hemispherical protrusions are both provided with guide holes, and the elastic rod passes through the guide holes of the joint ball;

[0022] An inner friction layer and an outer friction layer are fixedly connected to both sides of the joint ball, the inner friction layer is located between the outer friction layer and the second hemispherical protrusion, and the outer friction layer, the inner friction layer and the second hemispherical protrusion are arranged concentrically;

[0023] The outer side wall of the outer friction layer is also slidably connected with a cross ball ring.

[0024] Furthermore, when the steering ball unit is rotationally connected to the adjacent ball socket unit, the second hemispherical protrusion, the guide ring, the inner friction layer, the middle friction layer, the outer friction layer and the cross ball ring on the joint ball are sequentially connected and concentrically arranged;

[0025] The outer sliding platform on the outer side of 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.

[0026] Further, the end seat unit includes an end plate fixed to one end of the driving cable, a side wall of the end plate is fixedly connected to a terminal hemisphere, a third center hole is opened at the center position of the end plate and the terminal hemisphere, and a spring chuck is installed in the third center hole, a second conical surface adapted to the conical portion of the spring chuck is arranged in the third center hole, and the tail end of the elastic rod is connected to the spring chuck;

[0027] One end of the spring collet away from the conical portion is threadedly connected with a locking nut, and the locking nut is located in the third center hole of the terminal hemisphere;

[0028] An inner friction layer and an outer friction layer are fixedly connected to the side wall of the end plate, the inner friction layer is located between the outer friction layer and the end hemisphere, and the outer friction layer, the inner friction layer and the end hemisphere are arranged concentrically;

[0029] The outer side wall of the outer friction layer is also slidably connected with a cross ball ring.

[0030] Further, when the end seat unit is rotationally connected to the adjacent ball and socket unit, the end 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;

[0031] The outer sliding platform on the outer side of the cross ball ring in the end seat unit is embedded in the ball socket groove of the double ball socket sleeve and can slide along the ball socket groove.

[0032] Furthermore, a pin hole is provided on 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.

[0033] The present invention has at least the following beneficial effects:

[0034] 1. The present invention adds a cross ball ring between adjacent series units, and the inner and outer spherical surfaces of the cross are respectively provided with an inner slide and an outer slide, and the two slides are perpendicular to each other on the projection plane. By matching the two sets of slides with the outer slide groove and the ball socket groove, the torsion between adjacent series components is limited, thereby limiting the torsional freedom of the entire continuum robot, so that the robot has high torsional stiffness.

[0035] 2. The present invention sets an inner friction layer, a middle friction layer and an outer friction layer structure, and uses the inflation of a thin film airbag to squeeze each friction layer. Under the action of friction, the friction force between adjacent units is increased, so that there is a large friction locking torque between adjacent series units, thereby greatly changing the bending stiffness of the entire continuum robot.

[0036] 3. The present invention uses multiple layers of thin film airbags to extrude the friction layer after being stacked. Since the internal space of the thin film airbag is small and the cross-sectional area is large, the inflation and deflation speed of the airbag is very fast. Compared with the existing airbags that use filling particles to achieve changes in structural stiffness, the continuum robot of the present invention has a high stiffness change speed while obtaining a larger range of stiffness change capabilities.

[0037] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a cross-sectional schematic diagram of the overall structure of the present invention;

[0039] Figure 2is a cross-sectional schematic diagram of the drive unit structure in the present invention;

[0040] Figure 3 It is a cross-sectional schematic diagram of the driving unit structure at AA in the present invention;

[0041] Figure 4 is a three-dimensional schematic diagram of a film airbag assembly in the present invention;

[0042] Figure 5 It is a three-dimensional schematic diagram of the structure of the inner friction layer in the present invention;

[0043] Figure 6 It is a three-dimensional schematic diagram of the structure of the outer friction layer in the present invention;

[0044] Figure 7 It is a three-dimensional schematic diagram of the cross ball ring structure in the present invention;

[0045] Figure 8 is a cross-sectional schematic diagram of the ball and socket unit of the present invention;

[0046] Fig. 9 It is a three-dimensional schematic diagram of the double ball and socket sleeve structure of the present invention;

[0047] Fig.10 It is a cross-sectional schematic diagram of the steering ball unit in the present invention;

[0048] Fig.11 It is a cross-sectional schematic diagram of the end seat unit in the present invention;

[0049] Fig.12 It is a three-dimensional schematic diagram of the overall structure of the present invention.

[0050] Reference numerals:

[0051] 1. driving seat; 11. driving unit; 111. first conical surface; 112. through hole; 113. first center hole; 114. first cylinder; 12. spring chuck; 121. notch; 122. conical part; 13. locking nut; 14. film airbag assembly; 141. film airbag; 1411. air hole; 15. movable plate; 151. first hemispherical protrusion; 16. inner friction layer; 161. inner protrusion; 162. inner unloading groove; 17. outer friction layer; 171. outer slide groove; 172. outer unloading groove; 173. outer protrusion; 1 8. Cross ball ring; 181. Inner slide; 182. Outer slide; 19. Limiting pin; 20. Air pipe; 2. Elastic rod; 3. Driving cable; 4. Ball and socket unit; 41. Double ball and 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 hemispherical protrusion; 512. Guide hole; 6. End seat unit; 61. End plate; 611. Third center hole; 612. Second cone surface; 62. End hemisphere. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0053] See also Figure 1-12 The present invention provides a technical solution: a variable stiffness continuum robot, comprising a driving seat 1, a first central hole 113 is opened in the middle of the driving seat 1, a spring chuck 12 is installed inside the first central hole 113, a conical portion 122 is arranged on the top of the spring chuck 12, and a first conical surface 111 adapted to the conical portion 122 is arranged on the inner side wall of the first central hole 113 near the bottom;

[0054] like Figure 3 As shown, a resilient rod 2 is detachably mounted on the spring chuck 12, and one end of the spring chuck 12 away from the conical portion 122 passes through the end of the driving seat 1 and is threadedly connected with a locking nut 13, and a through hole 112 is provided at the center of the spring chuck 12, and a notch 121 is provided on the side wall of the conical portion 122. Therefore, by rotating the locking nut 13, the conical portion 122 is driven to squeeze the first conical surface 111. Under the constraint of the first conical surface 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 resilient rod 2 located in the central through hole 112 of the spring chuck 12. The provided resilient rod 2 can mainly play the role of connection and deformation, as shown in FIG. Fig.10 As shown;

[0055] A driving unit 11 is arranged on the side wall of the driving seat 1, and a ball and socket unit 4 is rotatably connected to the driving unit 11, and a steering ball unit 5 is rotatably connected to the other side of the ball and socket unit 4, and the number of the steering ball units 5 and the ball and socket units 4 is set to be multiple, and the steering ball units 5 and the ball and socket units 4 are arranged alternately;

[0056] One end of the ball and socket unit 4 is rotatably connected to the end seat unit 6, the elastic rod 2 penetrates the steering ball unit 5 and the ball and socket unit 4, and the tail end of the elastic rod 2 is detachably mounted on the end seat unit 6;

[0057] A plurality of driving cables 3 are fixedly connected to the end seat unit 6 . The plurality of driving cables 3 are arranged circumferentially as a whole, and all of the plurality of driving cables 3 pass through the steering ball unit 5 , the ball socket unit 4 , the driving unit 11 and the driving seat 1 .

[0058] According to the technical solution of this embodiment, the driving unit 11 includes a first cylinder 114 fixedly connected to the center of the driving seat 1. The first cylinder 114 is hollow inside and is connected to the first center hole 113. The first cylinder 114 and the driving seat 1 are integrally formed. The elastic rod 2 passes through the first cylinder 114 and the first center hole 113.

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

[0060] A first hemispherical protrusion 151 is arranged on the outer side of the movable plate 15, and 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, and the inner friction layer 16 and the outer friction layer 17 are both arranged in a spherical shape, and the sphere centers of the inner friction layer 16, the outer friction layer 17 and the first hemispherical protrusion 151 coincide with each other;

[0061] like Figure 5-7 As shown, an inner unloading groove 162 is provided on the side wall of the inner friction layer 16, an outer unloading groove 172 is provided on the side wall of the outer friction layer 17, and a cross ball ring 18 is slidably connected to the side wall 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 projections of the inner slide 181 and the outer slide 182 on the plane formed by the circular ring at the end 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, and an outer layer slide groove 171 matched with the inner slide 181 is provided on the outer side wall of the outer friction layer 17.

[0062] It should be noted that a pin hole is provided on the driving seat 1, in which a limiting rotation pin 19 is fixedly connected, and the other end of the limiting rotation pin 19 is slidably connected to the movable plate 15. The limiting rotation pin 19 is arranged through the movable plate 15. When the movable plate 15 slides up and down along the first cylinder 114, the limiting rotation pin 19 can provide it with limiting and guiding to prevent it from rotating.

[0063] Furthermore, if Figure 2 and Figure 4 As shown, the film airbag assembly 14 is formed by stacking multiple layers of film airbags 141, and the whole is configured in a corrugated tube shape. The interior of the multiple layers of film airbags 141 is provided with air holes 1411, and adjacent film airbags 141 are interconnected through the air holes 1411, and an air pipe 20 is installed through the side wall of the driving seat 1, and the air pipe 20 is connected to the air holes 1411. By introducing compressed gas into the air pipe 20, the film airbag assembly 14 will be inflated, thereby squeezing the movable plate 15 to slide along the axis direction of the first cylinder 114.

[0064] Furthermore, if Figure 5-6 As shown, a plurality of inner layer protrusions 161 are provided at the end of the inner friction layer 16, a plurality of outer layer protrusions 173 are provided at the end of the outer friction layer 17, and grooves matching the inner layer protrusions 161 and the outer layer protrusions 173 are provided on the side wall of the movable plate 15. 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 solution of this embodiment, Figure 8-9 As shown, the ball-and-socket unit 4 includes a double ball-and-socket sleeve 41, both ends of the double ball-and-socket sleeve 41 are provided with ball sockets 411, and a ball socket groove 412 is provided inside the ball socket 411;

[0066] A second center hole 413 is provided at the center of the double ball socket sleeve 41. The second center hole 413 is connected to the ball socket groove 412. Two guide rings 43 are symmetrically provided at both ends of the second center hole 413. The inner and outer surfaces of the two guide rings 43 are concentric spherical surfaces, and the two guide rings 43 are respectively concentric with the ball sockets 411 at both ends of the double ball socket sleeve 41.

[0067] 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 center hole 413 and can slide in the second center hole 413. The second cylinder 44 is hollow inside, and the second cylinder 44 and the guide ring 43 are connected. The second cylinder 44 and the guide ring 43 are integrally formed, and the elastic rod 2 passes through the second cylinder 44 and the second center hole 413.

[0068] A middle friction layer 42 is provided between the ball sockets 411 opened 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 both concentric spherical surfaces. The middle friction layer 42 is concentric with the ball sockets 411 , and the middle friction layer 42 is sleeved on the second cylinder 44 .

[0069] Specifically, when the drive unit 11 is rotationally connected to the ball and socket unit 4, the first hemispherical 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 on the end face of the movable plate 15 are connected in sequence and arranged concentrically, and the outer slide 182 on the outer side of the cross ball ring 18 in the drive 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 slide relatively between the first hemispherical protrusion 151 and the inner friction layer 16, the middle friction layer 42 can slide relatively between the inner friction layer 16 and the outer friction layer 17, and the outer slide 182 can slide relatively along the ball socket groove 412. In this way, the ball and socket unit 4 can deflect around the drive unit 11, thereby realizing steering, and the inner slide 181, the outer slide 182, the outer layer slide groove 171 and the ball socket groove 412 cooperate to limit the torsion between the drive unit 11 and the ball and socket unit 4 to avoid excessive torsional freedom.

[0070] For the technical solution of this embodiment, Fig.10 As shown, the steering ball unit 5 includes a joint ball 51, two second hemispherical protrusions 511 are arranged on both sides of the joint ball 51, and the two second hemispherical protrusions 511 are concentric, and the tops of the two second hemispherical protrusions 511 are both provided with guide holes 512, and the elastic rod 2 passes through the guide holes 512 of the joint ball 51;

[0071] The inner friction layer 16 and the outer friction layer 17 are fixedly connected to the two sides of the joint ball 51, respectively. The inner friction layer 16 is located between the outer friction layer 17 and the second hemispherical protrusion 511, and the outer friction layer 17, the inner friction layer 16 and the second hemispherical protrusion 511 are arranged concentrically.

[0072] The outer side wall of the outer friction layer 17 is also slidably connected with a cross ball ring 18 , and the inner and outer spherical surfaces of the cross ball ring 18 are also fixedly connected with an inner sliding platform 181 and an outer sliding platform 182 , respectively.

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

[0074] Specifically, when the steering ball unit 5 is rotatably connected to the adjacent ball and socket unit 4, the second hemispherical protrusion 511, 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 on the joint ball 51 are connected in sequence and arranged concentrically, and the outer slide 182 on the outer side of 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 slide relatively between the second hemispherical protrusion 511 and the inner friction layer 16, the middle friction layer 42 can slide relatively between the inner friction layer 16 and the outer friction layer 17, and the outer slide 182 can slide relatively along the ball socket groove 412. In this way, the steering ball unit 5 can deflect around the ball and socket unit 4, thereby realizing steering, and the inner slide 181, the outer slide 182, the outer layer slide groove 171 and the ball socket groove 412 cooperate to limit the torsion between the steering ball unit 5 and the ball and socket unit 4 to avoid excessive torsional freedom.

[0075] For the technical solution of this embodiment, Fig.11 As shown, the end seat unit 6 includes an end plate 61 fixed to one end of the driving cable 3, a terminal hemisphere 62 is fixedly connected to the side wall of the end plate 61, a third center hole 611 is opened at the center position of the end plate 61 and the terminal hemisphere 62, and a spring clamp 12 is installed in the third center hole 611, and a second tapered surface 612 adapted to the tapered portion 122 of the spring clamp 12 is provided in the third center hole 611, and the tail end of the elastic rod 2 is connected to the spring clamp 12;

[0076] The end of the spring chuck 12 away from the tapered portion 122 is threadedly connected with a locking nut 13, and the locking nut 13 is located in the third center hole 611 of the terminal hemisphere 62. Under the limiting effect of the second tapered surface 612, tightening the locking nut 13 drives the tapered portion 122 of the spring chuck 12 to deform, so that the tail end of the elastic rod 2 can be fixed on the spring chuck 12, thereby achieving 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 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;

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

[0079] Specifically, when the end seat unit 6 is rotationally connected with the adjacent ball and socket unit 4, the end 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 connected in sequence and arranged concentrically, and the outer slide 182 on the outer side of the cross ball ring 18 in the end 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 slide relative to each other between the end hemisphere 62 and the inner friction layer 16, the middle friction layer 42 can slide relative to each other between the inner friction layer 16 and the outer friction layer 17, and the outer slide 182 can slide relative to each other along the ball socket groove 412. In this way, the end seat unit 6 can deflect around the ball and socket unit 4, thereby realizing steering, and the inner slide 181, the outer slide 182, the outer layer slide groove 171 and the ball socket groove 412 cooperate to limit the torsion between the end seat unit 6 and the ball and socket unit 4 to avoid excessive torsional freedom.

[0080] For the technical solution of this embodiment, Fig.12 As shown, the number of drive cables 3 is set to three, and the three drive cables 3 are all fixed on the end plate 61 of the end seat unit 6. The three drive cables 3 are arranged circumferentially along the end plate 61, and the intervals between adjacent drive cables 3 are equal. The joint ball 51 and the side wall of the drive seat 1 are provided with through holes 112 for passing the drive cables 3. It should be noted that the free end of the drive cable 3 passed through the position of the drive seat 1 is connected to an external traction device, which can be set to a hydraulic rod, a traction machine, etc., which is not limited here and can be selected according to actual conditions.

[0081] The method and process of using the present invention:

[0082] like Fig.12 As shown, when bending is required, the driving cable 3 in the direction to be bent is pulled by an external traction device to be contracted, and the remaining driving cables 3 are appropriately relaxed to avoid interference. At this time, by making each driving cable 3 produce non-equal length displacement, the end plate 61 unit, the steering ball unit 5, and the ball socket unit 4 can be relatively rotated, thereby realizing the bending of the robot as a whole, which is convenient for realizing functions such as steering and obstacle avoidance;

[0083] When the film airbag 141 group is not filled with compressed gas, the movable plate 15 can slide freely along the axis of the first cylinder 114. At this time, the robot is in a flexible state and can bend freely. When the overall rigidity of the robot needs to be adjusted, compressed gas is first filled into the air pipe 20 with the help of an external air pump. The film airbag assembly 14 will be inflated and expanded, thereby squeezing the movable plate 15 to make it slide along the axis of the first cylinder 114. Since the two ends of the elastic rod 2 are respectively fixed to the end plate 61 and the driving seat 1, the total length of the robot will be constrained. At this time, after sliding, the movable plate 15 will first press the ball and socket unit 4 The steering head unit and the end plate 61 unit are squeezed through the ball and socket unit 4, so that the inner 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, thereby enhancing the friction between the units. At this time, the entire robot will change from a flexible state to a rigid state, and by adjusting the inflation size of the film airbag assembly 14, the friction between the units can be controlled, thereby controlling the stiffness of the robot, thereby facilitating the adaptive adjustment of the robot's use stiffness according to actual conditions, and further improving practicality.

[0084] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0085] For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. When an element is referred to as being "assembled on", "installed on", "fixed on" or "set on" another element, it can be directly on the other element or there can also be a centered element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a centered element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and are not intended to be the only implementation method.

[0086] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0087] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, 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 seat (1), characterized in that: A first central hole (113) is provided in the middle of the driving seat (1), a spring chuck (12) is installed inside the first central hole (113), a conical portion (122) is provided on the top of the spring chuck (12), a notch (121) is provided on the side wall of the conical portion (122), and a first conical surface (111) adapted to the conical portion (122) is provided on the inner side wall of the first central hole (113) near the bottom; An elastic rod (2) is detachably mounted on the spring chuck (12); one end of the spring chuck (12) away from the conical portion (122) passes through the end of the driving seat (1) and is threadedly connected to a locking nut (13); A driving unit (11) is arranged on the side wall of the driving seat (1), a ball socket unit (4) is rotatably connected to the driving unit (11), a steering ball unit (5) is rotatably connected to the other side of the ball socket unit (4), the steering ball units (5) and the ball socket units (4) are both provided in plural numbers, and the steering ball units (5) and the ball socket units (4) are arranged alternately; One end of the ball and socket unit (4) is rotatably connected to an end seat unit (6); the elastic rod (2) penetrates the steering ball unit (5) and the ball and socket unit (4); and the tail end of the elastic rod (2) is detachably mounted on the end seat unit (6); The end seat unit (6) is fixedly connected to a plurality of drive cables (3), the plurality of drive cables (3) are arranged circumferentially as a whole, and the plurality of drive cables (3) all pass through the steering ball unit (5), the drive unit (11) and the drive seat (1); The driving unit (11) comprises a first cylinder (114) fixedly connected to the center position of the driving seat (1); the first cylinder (114) is hollow inside and is connected to the first center hole (113); the elastic rod (2) is arranged to penetrate the first cylinder (114) and the first center hole (113); The outer surface of the first cylinder (114) is sleeved with a film airbag (141) assembly (14), the outer surface of the first cylinder (114) is slidably connected with a movable plate (15), and the film airbag (141) assembly (14) is located between the movable plate (15) and the driving seat (1); A first hemispherical protrusion (151) is arranged on the outer side of the movable plate (15); 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); the inner friction layer (16) and the outer friction layer (17) are both arranged in a spherical shape; and the sphere centers of the inner friction layer (16), the outer friction layer (17) and the first hemispherical protrusion (151) coincide with each other; An inner unloading groove (162) is provided on the side wall of the inner friction layer (16), an outer unloading groove (172) is provided on the side wall of the outer friction layer (17), and a cross ball ring (18) is slidably connected to the side wall of the outer friction layer (17), an inner sliding platform (181) is fixedly connected to the inner spherical surface of the cross ball ring (18), and an outer sliding platform (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 sliding groove (171) matched with the inner sliding platform (181) is provided on the outer side wall of the outer friction layer (17).

2. The variable stiffness continuum robot according to claim 1, characterized in that: The film airbag (141) assembly (14) is formed by stacking multiple layers of film airbags (141), which are configured as a bellows as a whole. The multiple layers of film airbags (141) are provided with air holes (1411) inside, and adjacent film airbags (141) are interconnected through the air holes (1411). An air pipe (20) is installed through the side wall of the driving seat (1), and the air pipe (20) is connected to the air holes (1411).

3. The variable stiffness continuum robot according to claim 1, characterized in that: The ball and socket unit (4) comprises a double ball and socket sleeve (41), both ends of the double ball and socket sleeve (41) are provided with ball sockets (411), and a ball socket groove (412) is provided inside the ball socket (411); A second center hole (413) is provided at the center of the double ball socket sleeve (41), and two guide rings (43) are symmetrically provided at both ends of the second center hole (413), the inner and outer surfaces of the guide rings (43) are both concentric spherical surfaces, and the two guide rings (43) are respectively concentric with the ball sockets (411) at both ends of the double ball socket sleeve (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 center 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 center hole (413); A middle friction layer (42) is provided between the ball sockets (411) opened 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 both concentric spherical surfaces; the middle friction layer (42) is concentric with the ball sockets (411), and the middle friction layer (42) is sleeved on the second cylinder (44).

4. The variable stiffness continuum robot according to claim 3, characterized in that: When the drive unit (11) is rotationally connected to the ball-and-socket unit (4), the first hemispherical protrusion (151) on the end surface of the movable plate (15), 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 arranged concentrically; The outer sliding platform (182) on the outer side of 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) and slides along the ball socket groove (412).

5. The variable stiffness continuum robot according to claim 4, characterized in that: The steering ball unit (5) comprises a joint ball (51), two second hemispherical protrusions (511) are arranged on both sides of the joint ball (51), and the two second hemispherical protrusions (511) are concentric, and the top ends of the two second hemispherical protrusions (511) are both provided with guide holes (512), and the elastic rod (2) passes through the guide holes (512) of the joint ball (51); An inner friction layer (16) and an outer friction layer (17) are fixedly connected to both sides of the joint ball (51), the inner friction layer (16) is located between the outer friction layer (17) and the second hemispherical protrusion (511), and the outer friction layer (17), the inner friction layer (16) and the second hemispherical protrusion (511) are arranged concentrically; The outer side wall of the outer friction layer (17) is also slidably connected with a cross ball ring (18).

6. The variable stiffness continuum robot according to claim 5, characterized in that: When the steering ball unit (5) is rotationally connected to the adjacent ball socket unit (4), the second hemispherical protrusion (511), 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) on the joint ball (51) are sequentially connected and concentrically arranged; The outer sliding platform (182) on the outer side of 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) and can slide along the ball socket groove (412).

7. The variable stiffness continuum robot according to claim 6, characterized in that: The end seat unit (6) comprises an end plate (61) fixed to one end of the driving cable (3), a side wall of the end plate (61) is fixedly connected to a terminal hemisphere (62), a third center hole (611) is provided at the center of the end plate (61) and the terminal hemisphere (62), a spring clamp (12) is installed in the third center hole (611), a second conical surface (612) adapted to the conical portion (122) of the spring clamp (12) is provided in the third center hole (611), and the tail end of the elastic rod (2) is connected to the spring clamp (12); One end of the spring chuck (12) away from the conical portion (122) is threadedly connected with a locking nut (13), and the locking nut (13) is located in the third center hole (611) of the terminal 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 side wall of the outer friction layer (17) is also slidably connected with a cross ball ring (18).

8. The variable stiffness continuum robot according to claim 7, characterized in that: When the end seat unit (6) is rotatably connected to the adjacent ball socket unit (4), the end 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) on the outer side of the cross ball ring (18) in the end seat unit (6) is embedded in the ball socket groove (412) of the double ball socket sleeve (41) and can slide along the ball socket groove (412).

9. The variable stiffness continuum robot according to claim 7, characterized in that: The driving seat (1) is provided with a pin hole, a rotation-limiting pin (19) is fixedly connected in the pin hole, and the other end of the rotation-limiting pin (19) is slidably connected in the movable plate (15).

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