Force locking variable stiffness continuum robot based on multi-strand rope torsion

Abstract

The invention discloses a force locking variable-rigidity continuum robot based on multi-strand rope torsion, which comprises working equipment, and further comprises a rack body, and a bending control device, a rigidity control device and a mechanical arm assembly which are mounted through the rack body, and the bending control device is matched with a plurality of strands of bending control ropes, the bending control rope controls the bending degree of the mechanical arm assembly, the rigidity control device is matched with a rigidity control rope, and the rigidity of the mechanical arm assembly is controlled through the rigidity control rope. Through independent control of each bending control rope, the joint bodies are driven to independently deflect along the bearing bone disc, so that the different joint bodies of the force-locking variable-rigidity continuum mechanical arm can independently curl, in addition, the mechanical arm assembly can adapt to the environment to change the rigidity through the arrangement of the rigidity control ropes, and the mechanical arm assembly is more flexible. And the bending control rope and the rigidity control rope are matched, so that the product can be bent at multiple angles in a complex working environment.

Description

Technical Field

[0001] The present invention relates to a force-locking variable-stiffness continuum robot based on the torsion of multi-strand ropes. Background Art

[0002] With the rapid development of the aviation, nuclear industry, and medical fields, the manipulators connected by rigid rods have technical problems such as low flexibility, low precision, and insufficient stiffness in extreme environments such as complex, narrow, and high-risk environments.

[0003] In order to improve the detection and grasping performance of the manipulator in extreme working environments, related technologies provide a force-locking variable-stiffness continuum manipulator based on the torsion of multi-strand ropes. Through the cooperative design of the stiffness control ropes and the motors, the ropes are tightened or relaxed under the control of the motors, so that the stiffness of the ropes changes. The manipulator realizes the stiffness change of the flexible manipulator through stiffness control. At the same time, by controlling the telescopic lengths of multiple adjusting ropes with multiple linear motors, the continuum can be constrained to bend in different directions, thereby controlling the bending direction of the force-locking variable-stiffness continuum manipulator.

[0004] However, when the inner wall of the space where the working environment is located is of different widths or there are many untouchable obstacles, the above-mentioned force-locking variable-stiffness continuum manipulator cannot realize its steering function in complex working environments and cannot meet higher stiffness requirements. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a force-locking variable-stiffness continuum robot based on the torsion of multi-strand ropes, which has high stability, high flexibility comprehensive qualities, and variable stiffness.

[0006] To solve the above problems, the present invention adopts the following technical solutions: A force-locking variable-stiffness continuum robot based on the torsion of multi-strand ropes includes a working device, a frame body, a bending control device, a stiffness control device, and a manipulator assembly installed through the frame body. A plurality of multi-strand bending control ropes are coordinated through the bending control device, and the bending control ropes control the bending degree of the manipulator assembly. A stiffness control rope is coordinated through the stiffness control device, and the stiffness of the manipulator assembly is controlled through the stiffness control rope. The working device is installed at the end of the manipulator assembly.

[0007] Preferably, the manipulator assembly includes a joint body and a connector. The connector is installed through the frame body, the joint body is fixedly installed through the connector, both the bending control rope and the stiffness control rope pass through the connector, the joint body is provided with multiple sections, a bearing pelvis is rotatably installed between adjacent joint bodies, and the working device is fixed through the bearing pelvis at the end.

[0008] Preferably, an elastic outer shell is sleeved outside the robotic arm assembly. While protecting the robotic arm assembly, the elastic outer shell reduces the influence on the bending movement of the robotic arm assembly in all directions.

[0009] Preferably, the joint body includes a convex support bone plate and a concave support bone plate. Both ends of the convex support bone plate have spherical convex surfaces, and both ends of the concave support bone plate have concave surfaces that fit the convex surfaces. Both ends of each joint body are convex support bone plates. The receiving bone plate is received between the two convex support bone plates. First concave surfaces for fitting the convex surfaces are machined at both ends of the receiving bone plate. First rope-passing holes for passing through the stiffness control ropes are provided at the axes of the convex support bone plate, the concave support bone plate, and the receiving bone plate. Second rope-passing holes for passing through the bending control ropes are correspondingly provided on the end faces of the convex support bone plate, the concave support bone plate, and the receiving bone plate. The second rope-passing holes are annularly distributed. After passing through the first rope-passing holes, the stiffness control ropes are fixed to the working device. After passing through a plurality of the second rope-passing holes, the bending control ropes are also fixed to the working device.

[0010] Preferably, the bending control device includes upper, middle, and lower sub-control mechanisms. Each sub-control mechanism includes 3 linear drive mechanisms arranged horizontally. Each linear drive structure cooperates with a slider. The slider horizontally moves laterally under the drive of the linear drive mechanism. The end of the bending control rope far from the working device is fixed to the slider. The second rope-passing holes are divided into a first hole position, a second hole position, and a third hole position. There are 3 first hole positions, 3 second hole positions, and 3 third hole positions all arranged annularly. The bending control ropes in the upper layer pass through the first hole position, the bending control ropes in the middle layer pass through the second hole position, and the bending control ropes in the lower layer pass through the third hole position.

[0011] Preferably, the connector includes a sleeve seat and a sleeve. The sleeve seat is fixed to the frame body. The sleeve is inserted into the sleeve seat and axially displaces along the sleeve seat. A first connecting plate is provided outside the sleeve seat and fixed to the frame body through the connecting seat. A guide rod is fixed through the connecting plate. A second connecting plate is provided outside the sleeve. The guide rod passes through the second connecting plate and is matched with a limit screw. The limit screw forms a limit on the displacement of the sleeve in the direction away from the sleeve seat. Third rope-passing holes corresponding to the second rope-passing holes are machined on the end face of the sleeve. Fourth rope-passing holes corresponding to the first rope-passing holes are machined at the axis of the sleeve. The sleeve seat passes through the frame body and then connects the receiving bone plate. The bending control rope passes through from the third rope-passing holes, and the stiffness control rope passes through from the fourth rope-passing holes.

[0012] Preferably, the stiffness control device includes a support rod, a mounting platform, and a torsion motor. There are four support rods distributed in a rectangular shape. The mounting platform is installed through the support rods. The torsion motor is fixed on the mounting platform. A rope threading seat is installed at the output end of the torsion motor. The end of the stiffness control rope away from the working device is fixed in the rope threading seat. A wire passing platform is also arranged between the multiple support rods, and part of the bending control rope passes through the upper part of the wire passing platform.

[0013] Preferably, the bending control rope is a steel wire rope with a wire diameter of 1 mm.

[0014] Preferably, the stiffness control rope is obtained by winding multiple strands of nylon ropes, and the wire diameter of each nylon rope is 1 mm.

[0015] The beneficial effects of the present invention are as follows: A force-locking variable-stiffness continuum manipulator provided by the present invention drives the joint body to independently deflect along the receiving pelvic bone through the independent control of each bending control rope, enabling the different joint bodies of the force-locking variable-stiffness continuum manipulator to achieve independent curling movements. In addition, the setting of the stiffness control rope also enables the manipulator assembly to adapt to the environment and change the stiffness. The cooperation of the bending control rope and the stiffness control rope enables the product to achieve multi-angle bending in a complex working environment, and at the same time has the comprehensive qualities of high stability, high flexibility, and selectable stiffness. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 is a structural schematic diagram of the present invention; Figure 2 is a three-dimensional view of the manipulator assembly; Figure 3 is a three-dimensional view of the concave support pelvic bone; Figure 4 is a three-dimensional view of the convex support pelvic bone; Figure 5 is a three-dimensional view of the receiving pelvic bone; Figure 6 is a distribution diagram of the first hole positions; Figure 7 is a distribution diagram of the second hole positions; Figure 8 is a distribution diagram of the third hole positions; Figure 9 is a structural diagram of the connector; Figure 10 is the end face view of the connector; Figure 11 is the perspective view of the bending control device; Figure 12 is the perspective view of the stiffness control device; Figure 13 is the physical diagram of this device; Figure 14 is the physical diagram of this device. Detailed implementation manners

[0018] All features disclosed in this specification, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any manner.

[0019] Any feature disclosed in this specification (including any additional claims, abstract, and drawings), unless specifically stated, can be replaced by other equivalent or features with similar purposes. That is, unless specifically stated, each feature is only an example in a series of equivalent or similar features.

[0020] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "one end", "the other end", "outer side", "upper", "inner side", "horizontal", "coaxial", "central", "end portion", "length", "outer end", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention.

[0021] In addition, in the description of the present invention, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0022] In the present invention, unless otherwise clearly specified and limited, the terms "set", "socket", "connect", "penetrate", "plug in", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] Refer to Figure 1A force-locked variable stiffness continuum robot based on multi-strand rope torsion shown in the figure includes a working device, a frame body 1, and a bending control device 2, a stiffness control device 3 and a robot arm assembly 4 installed through the frame body 1. The bending control device 2 is equipped with a multi-strand bending control rope 21, and the bending control rope 21 controls the bending degree of the robot arm assembly 4. The stiffness control device 3 is equipped with a stiffness control rope 31, and the stiffness of the robot arm assembly 4 is controlled by the stiffness control rope 31. The working equipment is installed at the end of the robot arm assembly 4.

[0024] The working equipment is a robot.

[0025] See also Figure 2 As shown, the robotic arm assembly 4 includes a joint body 41 and a connector 42, the connector 42 is installed through the frame body 1, the joint body 41 is fixedly installed through the connector 42, the bending control rope 21 and the stiffness control rope 31 both pass through the connector 42, the joint body 41 is provided with multiple sections, and a receiving bone plate 43 is rotatably installed between adjacent joint bodies 41, and the working equipment is fixed by the receiving bone plate 43 at the end.

[0026] An elastic shell is sleeved on the outside of the mechanical arm assembly 4. The elastic shell protects the mechanical arm assembly 4 and reduces the influence on the bending movement of the mechanical arm assembly 4 in various directions.

[0027] See also Figures 2 to 5 As shown, the joint body 41 includes a convex supporting pelvis 410 and a concave supporting pelvis 411, the two ends of the convex supporting pelvis 410 have spherical convex surfaces 412, and the two ends of the concave supporting pelvis 411 have concave surfaces 413 that fit the convex surfaces 412. Both ends of each joint body 41 are convex supporting pelvis 410, and the receiving pelvis 43 is received between the two convex supporting pelvises 410. The two ends of the receiving pelvis 43 are processed with first concave surfaces 414 that match the convex surfaces 412. A first rope threading hole 441 for passing the stiffness control rope 31 is provided at the axis of the supporting pelvis 411 and the receiving pelvis 43, and second rope threading holes 442 for passing the bending control rope 21 are correspondingly provided on the end surfaces of the convex supporting pelvis 410, the concave supporting pelvis 411 and the receiving pelvis 43. The second rope threading holes 442 are distributed in a ring shape. The stiffness control rope 31 is fixed to the working equipment after passing through the first rope threading hole 441, and the bending control rope 21 is also fixed to the working equipment after passing through multiple second rope threading holes 442.

[0028] Equipment placement holes are also provided at the preset positions of each supporting pelvis.

[0029] See also Figure 1, Figure 6 , Figure 7 , Figure 8 and Figure 11 As shown in Figure 6 , Figure 7 , Figure 8 and Figure 11 , the bending control device 2 includes upper, middle and lower sub-control mechanisms. Each sub-control mechanism includes 3 linear drive mechanisms 221 arranged horizontally. Each linear drive structure 221 is matched with a slider 222. The slider 222 horizontally displaces laterally driven by the linear drive mechanism 221. The end of the bending control rope 21 far from the working device is fixed to the slider 222. The second rope-passing hole 442 is divided into a first hole position 4421, a second hole position 4422 and a third hole position 4423. There are 3 first hole positions 4421, second hole positions 4422 and third hole positions 4423 arranged in a ring. The upper bending control rope 21 passes through the first hole position 4421, the middle bending control rope 21 passes through the second hole position 4422, and the lower bending control rope 21 passes through the third hole position 4423.

[0030] Using three bending control ropes installed adjacent to each other at 120° to control the same joint body can make the force on each joint body more balanced, improve the stiffness, ensure good mechanical properties of the cantilever beam, and also ensure the operability and accuracy.

[0031] Referring to Figure 9 and Figure 10 As shown in Figure 9 and Figure 10 , the connector 42 includes a sleeve seat 421 and a sleeve 422. The sleeve seat 421 is fixed to the frame body 1. The sleeve 422 is inserted into the sleeve seat 421 and axially displaces along the sleeve seat 421. A first connecting plate 423 is arranged outside the sleeve seat 421 and is fixed to the frame body 1 through the connecting seat 423. A guide rod 424 is fixed through the connecting plate 423. A second connecting plate 425 is arranged outside the sleeve 422. The guide rod 424 passes through the second connecting plate 425 and is matched with a limit screw 426. The limit screw 426 limits the displacement of the sleeve 422 in the direction away from the sleeve seat 421. A third rope-passing hole 427 corresponding to the second rope-passing hole 442 is machined on the end face of the sleeve 422. A fourth rope-passing hole 428 corresponding to the first rope-passing hole 441 is machined at the axis of the sleeve 422. The sleeve seat 421 passes through the frame body 1 and then connects the bearing pelvis 43. The bending control rope 21 passes through the third rope-passing hole 427, and the stiffness control rope 31 passes through the fourth rope-passing hole 428.

[0032] In the above technical solution, the third rope-passing hole 427 and the fourth rope-passing hole 428 on the surface of the sleeve 422 can respectively guide the bending control rope 21 and the stiffness control rope 31.

[0033] Referring to Figure 1and Figure 12 As shown in Figure 12 , the stiffness control device 3 includes a support rod 331, a mounting platform 332, and a torsion motor 333. There are four support rods 331 distributed in a rectangular shape. The mounting platform 332 is mounted through the support rods 331. The torsion motor 333 is fixed on the mounting platform 332. A rope threading seat 334 is mounted at the output end of the torsion motor 333. The end of the stiffness control rope 31 away from the working device is fixed within the rope threading seat 334. A wire passing platform 335 is further provided between the multiple support rods 331, and part of the bending control rope 21 passes through the upper part of the wire passing platform 335.

[0034] In the above technical solution, the mounting height of the mounting platform 332 can be adjusted vertically along the support rod 331. After the adjustment is completed, it is fixed in position by means such as screwing to ensure that the height of the stiffness control rope 31 is equal to the height of the robotic arm assembly.

[0035] The bending control rope 21 is a steel wire rope with a wire diameter of 1 mm.

[0036] The stiffness control rope 31 is obtained by winding multiple strands of Vectran ropes, and the wire diameter of each Vectran rope is 1 mm.

[0037] Curling movement: The three bending control ropes 21 in the upper layer respectively pass through the first hole positions 4421, the three bending control ropes 21 in the middle layer respectively pass through the second hole positions 4422, and the three bending control ropes 21 in the lower layer respectively pass through the third hole positions 4423. After the above nine bending control ropes pass through the sleeve, they are connected to the slider 222 of the bending control device, and the stiffness control rope 31 remains stationary; the 9 bending control ropes respectively correspond to 9 linear driving mechanisms 221. The three linear driving mechanisms 221 in the same vertical direction drive the sliders 222 on them to move away from the robotic arm assembly 4, so that the bending control ropes 21 are in a tensioned state, while the other six linear driving mechanisms 221 drive the sliders 222 to move towards the robotic arm assembly 4, driving six adjacent bending control ropes 21 to be in a relaxed state, realizing the simultaneous bending of multiple joint bodies of the entire robotic arm assembly.

[0038] It should be noted that in the embodiment of the present invention, the independent bending movement of the joint body in different directions can be realized through the independent operation of each linear driving mechanism 221.

[0039] Variable stiffness movement: The stiffness control rope 31 passes through the first rope threading hole 441 at the center of each supporting pelvis on the robotic arm assembly in turn, and then passes through the corresponding fourth rope threading hole 428 on the sleeve to be connected to the rope threading seat of the corresponding line stiffness control device. When the stepper motor of the stiffness control device rotates clockwise, the stiffness control rope 31 connected thereto is driven to rotate, so that the stiffness control rope 31 is in a tensioned state, the length of the stiffness control rope 31 is shortened, and the stiffness of the stiffness control rope 31 is increased. As a result, the robotic arm assembly realizes the stiffness increasing movement, and the corresponding stiffness decreasing movement is the same.

[0040] The embodiment of the present invention adopts a variable stiffness design. Compared with the traditional flexible arm which has only a single stiffness, the present invention has more stiffness and can adapt to more complex environments. When the mechanical arm is in a retracted state, the tension on the axis is greater, which can provide greater stiffness and overcome the defects of the flexible arm itself. In addition, the present invention adopts a wire rope drive, which is more environmentally friendly and simpler than a hydraulic drive, and does not require an additional hydraulic device; compared with the gear motor drive design, it has better flexibility and greatly reduces the weight of the front-end mechanical arm.

[0041] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A force-locked variable stiffness continuum robot based on multi-strand torsion, including a working device, characterized in that: The invention also comprises a frame body (1), and a bending control device (2), a stiffness control device (3) and a mechanical arm assembly (4) installed through the frame body (1); the bending control device (2) is matched with a plurality of bending control ropes (21), and the bending control ropes (21) control the bending degree of the mechanical arm assembly (4); the stiffness control device (3) is matched with a stiffness control rope (31), and the stiffness of the mechanical arm assembly (4) is controlled through the stiffness control rope (31); and the working equipment is installed at the end of the mechanical arm assembly (4).

2. The force-locked variable stiffness continuum robot based on multi-strand rope torsion according to claim 1 is characterized in that: The mechanical arm assembly (4) comprises a joint body (41) and a connector (42), wherein the connector (42) is installed through the frame body (1), the joint body (41) is fixedly installed through the connector (42), the bending control rope (21) and the stiffness control rope (31) both pass through the connector (42), the joint body (41) is provided with a plurality of sections, and a receiving bone plate (43) is rotatably installed between adjacent joint bodies (41), and the working equipment is fixed through the receiving bone plate (43) at the end.

3. The force-locked variable stiffness continuum robot based on multi-strand rope torsion according to claim 2 is characterized in that: An elastic shell is sleeved on the outside of the mechanical arm assembly (4), and the elastic shell protects the mechanical arm assembly (4) while reducing the influence on the bending movement of the mechanical arm assembly (4) in various directions.

4. The force-locked variable stiffness continuum robot based on multi-strand torsion according to claim 2 is characterized in that: The joint body (41) comprises a convex supporting bone plate (410) and a concave supporting bone plate (411); both ends of the convex supporting bone plate (410) have spherical convex surfaces (412); both ends of the concave supporting bone plate (411) have concave surfaces (413) matching the convex surfaces (412); both ends of each joint body (41) are convex supporting bone plates (410); the receiving bone plate (43) is received between the two convex supporting bone plates (410); first concave surfaces (414) matching the convex surfaces (412) are processed at both ends of the receiving bone plate (43); A first rope threading hole (441) for passing a stiffness control rope (31) is provided at the axis of the concave supporting pelvis (411) and the receiving pelvis (43); second rope threading holes (442) for passing a bending control rope (21) are correspondingly provided on the end surfaces of the convex supporting pelvis (410), the concave supporting pelvis (411) and the receiving pelvis (43); the second rope threading holes (442) are distributed in a ring shape; the stiffness control rope (31) is fixed to the working device after passing through the first rope threading hole (441); and the bending control rope (21) is also fixed to the working device after passing through a plurality of the second rope threading holes (442).

5. The force-locked variable stiffness continuum robot based on multi-strand torsion according to claim 4 is characterized in that: The bending control device (2) comprises three groups of sub-control mechanisms, namely, upper, middle and lower groups. Each group of sub-control mechanisms comprises three linear drive mechanisms (221) arranged horizontally. Each linear drive mechanism (221) is matched with a slider (222). The slider (222) is horizontally displaced under the drive of the linear drive mechanism (221). The end of the bending control rope (21) away from the working device is fixed to the slider (222). The second rope threading hole (442) is divided into a first hole position (4421), a second hole position (4422) and a third hole position (4423). The first hole position (4421), the second hole position (4422) and the third hole position (4423) are all arranged in a ring shape. The upper bending control rope (21) passes through the first hole position (4421), the middle bending control rope (21) passes through the second hole position (4422), and the lower bending control rope (21) passes through the third hole position (4423).

6. The force-locked variable stiffness continuum robot based on multi-strand rope torsion according to claim 2 is characterized in that: The connector (42) comprises a sleeve seat (421) and a sleeve (422), wherein the sleeve seat (421) is fixed to the frame body (1), the sleeve (422) is inserted into the sleeve seat (421) and displaced along the axial direction of the sleeve seat (421), a first connecting plate (423) is arranged outside the sleeve seat (421), and the sleeve is fixed to the frame body (1) via the connecting seat (423), a guide rod (424) is fixed via the connecting plate (423), a second connecting plate (425) is arranged outside the sleeve (422), and the guide rod (424) passes through the second connecting plate (425) and cooperates with a limiting screw ( 426), the limit screw (426) limits the displacement of the sleeve (422) in the direction away from the sleeve seat (421), a third rope threading hole (427) corresponding to the second rope threading hole (442) is processed on the end surface of the sleeve (422), and a fourth rope threading hole (428) corresponding to the first rope threading hole (441) is processed at the axis of the sleeve (422), the sleeve seat (421) passes through the frame body (1) and then connects to the receiving bone plate (43), the bending control rope (21) passes through the third rope threading hole (427), and the stiffness control rope (31) passes through the fourth rope threading hole (428).

7. The force-locked variable stiffness continuum robot based on multi-strand torsion according to claim 1 is characterized in that: The stiffness control device (3) comprises a support rod (331), a mounting platform (332) and a torsion motor (333); the support rods (331) are four and arranged in a rectangular shape; the mounting platform (332) is mounted via the support rods (331); the torsion motor (333) is fixed on the mounting platform (332); a rope threading seat (334) is mounted at the output end of the torsion motor (333); the end of the stiffness control rope (31) away from the working device is fixed in the rope threading seat (334); and a wire-passing platform (335) is further arranged between the plurality of support rods (331); a portion of the bending control rope (21) passes through the upper portion of the wire-passing platform (335).

8. The force-locked variable stiffness continuum robot based on multi-strand torsion according to claim 1 is characterized in that: The bending control rope (21) is a steel wire rope with a wire diameter of 1 mm.

9. The force-locked variable stiffness continuum robot based on multi-strand torsion according to claim 1 is characterized in that: The stiffness control rope (31) is obtained by winding a plurality of Vectran ropes, and the wire diameter of each Vectran rope is 1 mm.

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