Inchworm mechanism based on magneto-rheological and passive joint

Abstract

The application relates to the mechanical technical field, in particular to a inchworm mechanism based on magneto-rheological and passive joints. The inchworm mechanism based on magneto-rheological and passive joints comprises a first push-moving assembly and a second push-moving assembly, the first push-moving assembly comprises a first frame body and a push rod, at least part of the push rod is arranged in the first frame body, and the push rod can move along a first direction relative to the first frame body; the second push-moving assembly comprises a second frame body and a rod body, the second frame body and the first frame body are arranged at intervals in the first direction, the first end of the rod body is connected with the second end of the push rod, the second end of the rod body extends into the second frame body, and the second frame body is filled with a variable stiffness medium; the stiffness of the variable stiffness medium can be adjusted to realize stepless locking of the rod body in the second frame body. The inchworm mechanism based on magneto-rheological and passive joints can realize adjustment of a step distance and improve the adaptability of the inchworm mechanism.

Description

Technical Field

[0001] This invention relates to the field of mechanical technology, specifically to an inchworm mechanism based on magnetorheology and passive joints. Background Technology

[0002] Inchworm mechanisms, which mimic the alternating creeping motion of an inchworm, are widely used in pipeline inspection, precision machining, and special robots. However, in related technologies, the fixed step distance of inchworm mechanisms makes it difficult to meet the operational requirements of high-precision micro-motion and high-efficiency movement, resulting in poor adaptability of inchworm mechanisms. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose an inchworm mechanism based on magnetorheology and passive joints, which can achieve step size adjustment and improve the adaptability of the inchworm mechanism.

[0004] The inchworm mechanism based on magnetorheology and passive joints according to an embodiment of the present invention includes: a first pushing assembly, the first pushing assembly including a first frame and a push rod, at least a portion of the push rod being disposed within the first frame and the push rod being movable relative to the first frame along a first direction; and a second pushing assembly, the second pushing assembly including a second frame and a rod, the second frame and the first frame being spaced apart in the first direction, a first end of the rod being connected to a second end of the push rod, the second end of the rod extending into the second frame, the second frame being filled with a variable stiffness medium, the stiffness of the variable stiffness medium being adjustable to achieve stepless locking of the rod within the second frame.

[0005] The inchworm mechanism based on magnetorheology and passive joints in this invention, by having at least a portion of a push rod disposed within a first frame and the push rod movable relative to the first frame in a first direction, with a first end of the rod connected to a second end of the push rod and the second end of the rod extending into a second frame, allows the push rod to move within the second frame when the variable stiffness medium within the second frame is of weak stiffness. By adjusting the variable stiffness medium within the second frame to strong stiffness to lock the position of the moved rod within the second frame, the distance between the first and second frames can be adjusted, thereby adjusting the step distance during the movement of the inchworm mechanism. This allows for adaptation to different step distance requirements and improves the adaptability of the inchworm mechanism.

[0006] In some embodiments, the first pushing assembly further includes a first piston assembly, the first piston assembly including a first cylinder and a first piston rod, the first cylinder being disposed on the first frame and movable relative to the first frame along the first direction, one end of the first piston rod being movably disposed on the first cylinder such that the other end of the first piston rod abuts or separates from the inner wall surface of the mounting space; the second pushing assembly further includes a second piston assembly, the second piston assembly including a second cylinder and a second piston rod, the second cylinder being disposed on the second frame and movable relative to the second frame along the first direction, one end of the second piston rod being movably disposed on the second cylinder such that the other end of the second piston rod abuts or separates from the inner wall surface of the mounting space.

[0007] In some embodiments, there are at least two first piston assemblies, which are arranged circumferentially on the first frame, and the axial direction of the first piston rod is orthogonal to the first direction. There are at least two second piston assemblies, which are arranged circumferentially on the second frame, and the axial direction of the second piston rod is orthogonal to the first direction.

[0008] In some embodiments, both the first cylinder and the second cylinder are filled with a variable stiffness medium. When the variable stiffness medium in the cylinder has a first stiffness, the piston rod abuts against the inner wall of the mounting space. When the variable stiffness medium in the cylinder has a second stiffness, the piston rod separates from the inner wall of the mounting space, and the second stiffness is less than the first stiffness.

[0009] In some embodiments, the first pushing assembly further includes a first joint assembly, the first joint assembly including a first link, a second link and a third link, a first end of the first link being hinged to an end of the first frame away from the second frame, a second end of the first link being hinged to the first end of the second link and the first end of the third link, a second end of the second link being hinged to the first end of the push rod, and a second end of the third link being hinged to the other end of the first piston rod.

[0010] In some embodiments, there are two first links, two second links, and two third links. The two first links are symmetrically arranged in a second direction orthogonal to the first direction, the two second links are symmetrically arranged in the second direction, and the two third links are symmetrically arranged in the second direction.

[0011] In some embodiments, the first joint assembly has a switchable first state and a second state. In the first state, the first link and the third link are substantially parallel. In the second state, the hinge joint of the first link and the third link moves in a direction close to the first frame to form an angle between the first link and the third link. When switching from the first state to the second state, the variable stiffness medium in the first cylinder has a second stiffness, and the variable stiffness medium in the second cylinder has a first stiffness. The third link drives the first piston assembly to move relative to the first frame in a direction away from the second piston assembly in the first direction. The second link applies a force to the push rod in a direction toward the rod body to move the first frame in a direction away from the second frame under the reaction force of the rod body. When switching from the second state to the first state, the variable stiffness medium in the first cylinder has a first stiffness, and the variable stiffness medium in the second cylinder has a second stiffness. The first link drives the first frame to move in a direction away from the second frame, and the second link drives the push rod to move in the first direction away from the rod body. The push rod drives the second pushing assembly to move in a direction close to the first frame.

[0012] In some embodiments, the variable stiffness medium in the first cylinder has a first stiffness, and the variable stiffness medium in the second cylinder has a second stiffness. When switching from the first state to the second state, the first connecting rod drives the first frame to move in the direction toward the second frame, and the second connecting rod pushes the push rod to move in the direction toward the second frame to push the second pushing assembly to move in the direction away from the first frame. The variable stiffness medium in the first cylinder has a second stiffness, and the variable stiffness medium in the second cylinder has a first stiffness. When switching from the second state to the first state, the second connecting rod applies a force to the push rod in the direction away from the rod to make the first frame move in the direction closer to the second frame under the reaction force of the rod. The third connecting rod drives the first piston assembly to move in the direction closer to the second piston assembly.

[0013] In some embodiments, the inchworm mechanism based on magnetorheology and passive joints further includes a second joint assembly, which includes a fourth link, a fifth link, and a sixth link. The first end of the fourth link is hinged to the second end of the push rod, the second end of the fourth link is hinged to the first ends of the fifth link and the sixth link, the second end of the fifth link is hinged to the first end of the rod body, and the second end of the sixth link is hinged to the other end of the second piston rod.

[0014] In some embodiments, the variable stiffness medium includes a magnetorheological medium, the second frame and the rod constitute a magnetorheological damper, and the damping force of the magnetorheological medium under the action of a magnetic field is adjustable to achieve stepless locking of the rod. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the first joint assembly of the inchworm mechanism based on magnetorheology and passive joints in an embodiment of the present invention in the first state.

[0016] Figure 2 This is a schematic diagram of the first joint assembly of the inchworm mechanism based on magnetorheology and passive joints in the second state according to an embodiment of the present invention.

[0017] Figure 3 This is one of the schematic diagrams of the second joint of the inchworm mechanism based on magnetorheology and passive joints in an embodiment of the present invention.

[0018] Figure 4 This is a second schematic diagram of the second joint of the inchworm mechanism based on magnetorheology and passive joints in an embodiment of the present invention.

[0019] Figure label:

[0020] The inner wall of the installation space is 100 mm. First pushing assembly 1, first frame 11, push rod 12 First piston assembly 13, first cylinder 131, first piston rod 132. First joint assembly 14, first link 141, second link 142, third link 143 Second pushing component 2, second frame 21, rod 22 Second piston assembly 23, second cylinder 231, second piston rod 232 Variable stiffness medium 3, Second joint assembly 4, fourth link 41, fifth link 42, sixth link 43. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0022] The following is in conjunction with the appendix Figures 1-4 The inchworm mechanism based on magnetorheology and passive joints according to embodiments of the present invention will be described in detail.

[0023] The inchworm mechanism based on magnetorheology and passive joints in this embodiment of the invention includes a first pushing assembly 1 and a second pushing assembly 2. The first pushing assembly 1 includes a first frame 11 and a push rod 12. At least a portion of the push rod 12 is disposed within the first frame 11 and the push rod 12 is movable relative to the first frame 11 along a first direction. The second pushing assembly 2 includes a second frame 21 and a rod 22. The second frame 21 and the first frame 11 are spaced apart in the first direction. The first end of the rod 22 is connected to the second end of the push rod 12, and the second end of the rod 22 extends into the second frame 21. The second frame 21 is filled with a variable stiffness medium 3, and the stiffness of the variable stiffness medium 3 is adjustable to achieve stepless locking of the rod 22 within the second frame 21.

[0024] The inchworm mechanism based on magnetorheology and passive joints in this embodiment of the invention, by having at least a portion of the push rod 12 disposed within the first frame 11 and the push rod 12 movable relative to the first frame 11 along a first direction, with the first end of the rod 22 connected to the second end of the push rod 12 and the second end of the rod 22 extending into the second frame 21, allows the push rod 12 to drive the rod 22 to move within the second frame 21 when the variable stiffness medium 3 within the second frame 21 is of weak stiffness. By adjusting the variable stiffness medium 3 within the second frame 21 to strong stiffness to lock the position of the moved rod 22 within the second frame 21, the distance between the first frame 11 and the second frame 21 can be adjusted, thereby adjusting the step distance during the movement of the inchworm mechanism. This allows for adaptation to different step distance requirements and improves the adaptability of the inchworm mechanism.

[0025] Specifically, such as Figures 1-4 As shown, the first direction is the front-to-back direction. The first frame 11 and the second frame 21 are arranged at intervals in the front-to-back direction, with the first frame 11 located in front of the second frame 21. The front end of the rod 22 is connected to the rear end of the push rod 12, and the rear end of the rod 22 extends into the second frame 21, which facilitates the push rod 12 to push the rod 22 to move within the second frame 21.

[0026] The stiffness of the variable stiffness medium 3 can switch between high stiffness and low stiffness. When the stiffness of the variable stiffness medium 3 is low stiffness, the push rod 12 can push the rod 22 forward or backward within the second frame 21, achieving full-stroke movement of the rod 22 within the second frame 21. When the stiffness of the variable stiffness medium 3 is high stiffness, the variable stiffness medium 3 can lock the position of the rod 22 within the second frame 21, preventing the rod 22 from moving. Stepless locking can be understood as locking the rod 22 at any position within its full stroke range within the second frame 21 through the stiffness adjustment of the push rod 12 and the variable stiffness medium 3.

[0027] When the rod 22 is at its rearmost end within its movable range, the distance between the first frame 11 and the second frame 21 is minimized, and the movement step of the inchworm mechanism is minimized, enabling micro-motion of the inchworm mechanism, which is suitable for high-precision operation scenarios such as precision equipment adjustment.

[0028] When the rod 22 is at its foremost position within its movable range, the distance between the first frame 11 and the second frame 21 is at its maximum, and the inchworm mechanism has the largest step distance, enabling the inchworm mechanism to move quickly and making it suitable for high-efficiency movement under normal working conditions.

[0029] When the rod 22 is located between the foremost and rearmost ends within its movable range, the interval between the first frame 11 and the second frame 21 is between the maximum and minimum interval. The inchworm mechanism has a moderate step size, which enables the inchworm mechanism to walk slowly and is suitable for smooth movement in confined spaces.

[0030] The inchworm mechanism based on magnetorheology and passive joints in this embodiment of the invention realizes different movement modes of micro-movement, fast walking and slow walking through the linkage of push rod 12 and rod 22 and the fact that rod 22 can stay at any position in the second frame 21 throughout its full stroke. The movement modes are diversified and adaptable to different working speed and precision requirements.

[0031] Optionally, the push rod 12 is an electromagnetic push-pull rod, which has precise power transmission and fast response speed. By precisely controlling the timing of applying an external magnetic field to the front or rear end of the electromagnetic push-pull rod, precise control of the electromagnetic push-pull rod can be achieved, thereby achieving precise adjustment of the position of the rod body 22.

[0032] Optionally, the first frame 11 and the second frame 21 can be made of lightweight, high-strength alloy material to reduce the overall weight of the inchworm mechanism and improve its portability and mobility.

[0033] In some embodiments, the variable stiffness medium 3 includes a magnetorheological medium, and the second frame 21 and the rod 22 constitute a magnetorheological damper. The damping force of the magnetorheological medium under the action of a magnetic field is adjustable to achieve stepless locking of the rod 22.

[0034] Specifically, such as Figures 1-4As shown, the second frame 21 and the rod 22 constitute a magnetorheological damper. The second frame 21 is filled with a magnetorheological medium, which has controllable fluidity. When an external magnetic field of saturation is applied, the magnetorheological medium exhibits a high viscosity and high stiffness state, with the strongest damping force. By reducing the strength of the external magnetic field, the viscosity of the magnetorheological medium changes synchronously with the magnetic field, and the stiffness changes weakly, exhibiting a low viscosity and low stiffness state, with a smaller damping force. By adjusting the damping force of the push rod 12 and the magnetorheological medium under the action of the magnetic field, the rod 22 can be stopped at any position within the entire stroke range, thereby determining the movement step of the first frame 11 and realizing stepless speed regulation of the inchworm mechanism's movement step.

[0035] In some embodiments, such as Figures 1-4 As shown, the first pushing assembly 1 also includes a first piston assembly 13. The first piston assembly 13 includes a first cylinder 131 and a first piston rod 132. The first cylinder 131 is disposed on the first frame 11 and can move relative to the first frame 11 in a first direction. One end of the first piston rod 132 is movably disposed on the first cylinder 131 so that the other end of the first piston rod 132 abuts against or separates from the inner wall surface 100 of the installation space. By disposing the first cylinder 131 on the first frame 11 and movably disposing the first piston rod 132 on the first cylinder 131, and by utilizing the abutment of the first piston rod 132 against the inner wall surface 100 of the installation space, it is convenient to fix the first piston assembly 13, thereby facilitating the fixation of the position of the first pushing assembly 1 in the installation space. By utilizing the separation of the first piston rod 132 from the inner wall surface 100 of the installation space, it is convenient to realize the movement of the first pushing assembly 1 in the installation space.

[0036] The second pushing assembly 2 also includes a second piston assembly 23, which includes a second cylinder 231 and a second piston rod 232. The second cylinder 231 is disposed on the second frame 21 and is movable relative to the second frame 21 in a first direction. One end of the second piston rod 232 is movably disposed on the second cylinder 231, so that the other end of the second piston rod 232 abuts against or separates from the inner wall surface 100 of the installation space. By disposing the second cylinder 231 on the second frame 21 and movably disposing the second piston rod 232 on the second cylinder 231, and by utilizing the contact between the second piston rod 232 and the inner wall surface 100 of the installation space, it is easy to fix the second piston assembly 23, thereby facilitating the fixation of the position of the second pushing assembly 2 within the installation space. By utilizing the separation of the second piston rod 232 from the inner wall surface 100 of the installation space, it is easy to enable the second pushing assembly 2 to move within the installation space.

[0037] Understandably, the piston assembly is movably mounted on the frame. When the piston assembly abuts against the inner wall 100 of the installation space, the position of the piston assembly within the installation space is fixed. At this time, under the action of external force, the piston assembly cannot move forward or backward. However, under the action of external force, the frame can move forward or backward relative to the piston assembly.

[0038] The installation space can be a pipe or a channel. That is to say, the inchworm mechanism can be installed in a pipe or a narrow channel. The inchworm mechanism is fixed in the pipe or channel by the first piston rod 132 abutting against the inner wall surface of the pipe or the channel and / or the second piston rod 232 abutting against the inner wall surface of the pipe or the channel, so as to perform detection, dredging or other operations.

[0039] In some embodiments, such as Figures 1-4 As shown, there are at least two first piston assemblies 13, which are arranged at intervals in the circumferential direction of the first frame 11. The axial direction of the first piston rod 132 is orthogonal to the first direction. By setting at least two first piston assemblies 13, it is convenient for at least two first piston assemblies 13 to simultaneously abut against the inner wall surface 100 of the installation space, thereby improving the connection between the first piston assembly 13 and the inner wall surface 100 of the installation space.

[0040] At least two second piston assemblies 23 are arranged at intervals in the circumferential direction of the second frame 21, and the axial direction of the second piston rod 232 is orthogonal to the first direction. By setting at least two second piston assemblies 23, it is convenient for at least two second piston assemblies 23 to simultaneously abut against the inner wall surface 100 of the installation space, thereby improving the connection strength between the second piston assemblies 23 and the inner wall surface 100 of the installation space.

[0041] In some embodiments, both the first cylinder 131 and the second cylinder 231 are filled with a variable stiffness medium 3. When the variable stiffness medium 3 in the cylinder has a first stiffness, the piston rod abuts against the inner wall surface 100 of the installation space. When the variable stiffness medium 3 in the cylinder has a second stiffness, the piston rod separates from the inner wall surface 100 of the installation space, and the second stiffness is less than the first stiffness.

[0042] Specifically, such as Figures 1-4 As shown, the first stiffness corresponds to the strong stiffness, and the second stiffness corresponds to the weak stiffness. When the first piston assembly 13 and / or the second piston assembly 23 do not need to move forward or backward, the stiffness of the variable stiffness medium 3 in the first cylinder 131 and / or the second cylinder 231 is the first stiffness, so that the first piston rod 132 abuts against the inner wall surface 100 of the installation space and / or the second piston rod 232 abuts against the inner wall surface 100 of the installation space. Under the action of no external force, the first pushing assembly 1 and / or the second pushing assembly 2 are fixed, thereby realizing the fixed-point stopping of the inchworm mechanism.

[0043] When the first piston assembly 13 and / or the second piston assembly 23 need to move forward or backward, the stiffness of the variable stiffness medium 3 in the first cylinder 131 and / or the second cylinder 231 is the second stiffness, which causes the first piston rod 132 to separate from the inner wall surface 100 of the installation space and / or the second piston rod 232 to separate from the inner wall surface 100 of the installation space. Under the action of external force, the first pushing assembly 1 and / or the second pushing assembly 2 are moved, thereby realizing the movement of the inchworm mechanism.

[0044] Understandably, after the stiffness of the variable stiffness medium 3 is adjusted from the first stiffness to the second stiffness, the piston rod no longer abuts against the inner wall surface 100 of the installation space. Under the action of external force, the piston rod can move forward or backward.

[0045] Optionally, the variable stiffness medium 3 filled in the first cylinder 131 and the second cylinder 231 can be a magnetorheological medium, and the stiffness switching of the magnetorheological medium can be precisely controlled by applying and weakening an external magnetic field.

[0046] In some embodiments, the first pushing assembly 1 further includes a first joint assembly 14, which includes a first link 141, a second link 142, and a third link 143. The first end of the first link 141 is hinged to the end of the first frame 11 away from the second frame 21. The second end of the first link 141 is hinged to the first ends of the second link 142 and the first ends of the third link 143. The second end of the second link 142 is hinged to the first end of the push rod 12. The second end of the third link 143 is hinged to the other end of the first piston rod 132.

[0047] Specifically, such as Figures 1-4 As shown, the front end of the first link 141 is hinged to the front end of the first frame 11, the rear end of the first link 141 is hinged to the front end of the second link 142 and the front end of the third link 143, the rear end of the second link 142 is hinged to the front end of the push rod 12, and the rear end of the third link 143 is hinged to the other end of the first piston rod 132. Through the linkage of the first link 141, the second link 142 and the third link 143, the movement of the first frame 11, the first piston rod 132 and the push rod 12 can be directly driven, thereby realizing the movement of the inchworm mechanism. Moreover, the structure of the first joint assembly 14 is simple, which can reduce the complexity of the inchworm mechanism.

[0048] In some embodiments, there are two first links 141, two second links 142, and two third links 143. The two first links 141 are symmetrically arranged in a second direction orthogonal to the first direction, the two second links 142 are symmetrically arranged in the second direction, and the two third links 143 are symmetrically arranged in the second direction.

[0049] Specifically, such as Figures 1-4 As shown, the second direction is the vertical direction. The two first connecting rods 141 are symmetrically arranged in the vertical direction, the two second connecting rods 142 are symmetrically arranged in the vertical direction, and the two third connecting rods 143 are symmetrically arranged in the vertical direction. The front ends of the upper first connecting rod 141, the lower first connecting rod 141, and the front end of the first frame 11 are coaxially hinged. The rear ends of the upper second connecting rod 142, the lower second connecting rod 142, and the front end of the push rod 12 are coaxially hinged. The rear end of the upper third connecting rod 143 is hinged to the other end of the first piston rod 132 of the upper first piston assembly 13, and the rear end of the lower third connecting rod 143 is hinged to the other end of the first piston rod 132 of the lower first piston assembly 13, which facilitates the simultaneous movement of the two piston assemblies forward or backward.

[0050] In some embodiments, the first joint assembly 14 has a switchable first state and a second state. In the first state, the first link 141 and the third link 143 are substantially parallel. In the second state, the hinge joint of the first link 141 and the third link 143 moves in a direction close to the first frame 11 to form an angle between the first link 141 and the third link 143. When switching from the first state to the second state, the stiffness of the variable stiffness medium 3 in the first cylinder 131 is the second stiffness, and the stiffness of the variable stiffness medium 3 in the second cylinder 231 is the first stiffness. The third connecting rod 143 drives the first piston assembly 13 to move relative to the first frame 11 in a direction away from the second piston assembly 23 in a first direction. The second connecting rod 142 applies a force to the push rod 12 in the direction toward the rod body 22, so that the first frame 11 moves away from the second frame 21 under the reaction force of the rod body 22. When switching from the second state to the first state, the stiffness of the variable stiffness medium 3 in the first cylinder 131 is the first stiffness, and the stiffness of the variable stiffness medium 3 in the second cylinder 231 is the second stiffness. The first connecting rod 141 drives the first frame 11 to move away from the second frame 21, the second connecting rod 142 drives the push rod 12 to move away from the rod 22 in the first direction, and the push rod 12 drives the second pushing assembly 2 to move towards the first frame 11.

[0051] Specifically, such as Figure 1 As shown, the first joint assembly 14 is in the first state, and the first link 141 and the third link 143 are generally parallel, as shown. Figure 2As shown, the first joint assembly 14 is in the second state, and the hinge of the first link 141 and the third link 143 moves in the direction close to the first frame 11. An angle is formed between the first link 141 and the third link 143. The movement of the inchworm mechanism can be realized by switching the first joint assembly 14 between the first state and the second state and by adjusting the stiffness of the variable stiffness medium 3 in the cylinder.

[0052] When the inchworm mechanism needs to move forward, the stiffness of the variable stiffness medium 3 in the first cylinder 131 is the second stiffness, and the stiffness of the variable stiffness medium 3 in the second cylinder 231 is the first stiffness. At this time, the second pushing assembly 2 is fixed in the installation space, and the first piston assembly 13 is separated from the inner wall 100 of the installation space. Under the action of external force, the first joint assembly 14 switches from the first state to the second state, and the hinge of the first connecting rod 141 and the third connecting rod 143 moves in the direction close to the first frame 11, so that the third connecting rod 143 drives the first piston rod 132 to move forward. The first piston rod 132 drives the first cylinder 131 to move forward synchronously. The second connecting rod 142 applies a backward force to the push rod 12. Since the push rod 12 is connected to the rod 22 and the overall position of the second pushing assembly 2 is relatively fixed, that is, the positions of the second pushing assembly 2 and the push rod 12 are relatively fixed, so that the first frame 11 moves forward under the reaction force of the rod 22. The first frame 11 drives the first piston assembly 13 and the first joint assembly 14 to move forward. The push rod 12 is positioned further back relative to the first frame 11, realizing the forward movement of the first pushing assembly 1. At this point, the stiffness of the variable stiffness medium 3 in the first cylinder 131 is adjusted to the first stiffness, and the stiffness of the variable stiffness medium 3 in the second cylinder 231 is adjusted to the second stiffness. The first joint assembly 14 switches from the second state to the first state, and the first connecting rod 141 and the third connecting rod 143 gradually return to being approximately parallel. Since the first piston assembly 13 abuts against the inner wall 100 of the installation space, the first connecting rod 141 drives the first frame 11 to move forward, the second connecting rod 142 drives the push rod 12 to move forward, and the push rod 12 drives the second pushing assembly 2 to move forward, thus realizing the forward movement of the second pushing assembly 2. By repeating the above steps of the first pushing assembly 1 and the second pushing assembly 2 moving forward, the inchworm mechanism can move forward continuously and stably.

[0053] In some embodiments, such as Figures 1-2 As shown, the variable stiffness medium 3 in the first cylinder 131 has a first stiffness, and the variable stiffness medium 3 in the second cylinder 231 has a second stiffness. When switching from the first state to the second state, the first connecting rod 141 drives the first frame 11 to move in the direction toward the second frame 21, and the second connecting rod 142 pushes the push rod 12 to move in the direction toward the second frame 21 to push the second pushing assembly 2 to move in the direction away from the first frame 11. The variable stiffness medium 3 in the first cylinder 131 has a second stiffness, and the variable stiffness medium 3 in the second cylinder 231 has a first stiffness. When switching from the second state to the first state, the second connecting rod 142 applies a force to the push rod 12 in a direction away from the rod 22 so that the first frame 11 moves in a direction close to the second frame 21 under the reaction force of the rod 22. The third connecting rod 143 drives the first piston assembly 13 to move in a direction close to the second piston assembly 23.

[0054] When the inchworm mechanism needs to move backward, the stiffness of the variable stiffness medium 3 in the first cylinder 131 is the first stiffness, and the stiffness of the variable stiffness medium 3 in the second cylinder 231 is the second stiffness. At this time, the first piston assembly 13 abuts against the inner wall surface 100 of the installation space, and the second piston assembly 23 separates from the inner wall surface 100 of the installation space. Under the action of external force, the first joint assembly 14 switches from the first state to the second state. The hinge of the first connecting rod 141 and the third connecting rod 143 moves in the direction close to the first frame 11, so that the first connecting rod 141 drives the first frame 11 to move backward. The second connecting rod 142 pushes the push rod 12 to move backward, and the push rod 12 pushes the second pushing assembly 2 to move backward, thereby realizing the backward movement of the second pushing assembly 2. At this time, the stiffness of the variable stiffness medium 3 in the first cylinder 131 is set to the second stiffness, and the stiffness of the variable stiffness medium 3 in the second cylinder 231 is set to the first stiffness. The first joint assembly 14 switches from the second state to the first state. The first connecting rod 141 and the third connecting rod 143 gradually return to being roughly parallel. Since the second piston assembly 23 abuts against the inner wall surface 100 of the installation space, the first piston assembly 13 separates from the inner wall surface 100 of the installation space, causing the third connecting rod 143 to drive the first piston assembly 13 to move backward. The second connecting rod 142 applies a forward force to the push rod 12. Since the push rod 12 is connected to the rod body 22 and the overall position of the second pushing assembly 2 is relatively fixed, the first frame 11 moves backward under the reaction force of the rod body 22. The first frame 11 drives the first piston assembly 13 and the first joint assembly 14 to move backward. The position of the push rod 12 relative to the first frame 11 is further forward, realizing the backward movement of the first pushing assembly 1. By repeating the steps of the second pushing component 2 and the first pushing component 1 moving backward, the inchworm mechanism can move backward continuously and stably.

[0055] This invention achieves the adjustment of the stiffness of the variable stiffness medium 3 in the first cylinder 131 and the variable stiffness medium 3 in the second cylinder 231 by alternately applying and weakening the external magnetic field. This allows for the alternating switching of the strong stiffness of the variable stiffness medium 3 in the first cylinder 131 and the strong stiffness of the variable stiffness medium 3 in the second cylinder 231. In conjunction with the switching of the first joint assembly 14 from the first state to the second state or from the second state to the first state, the inchworm mechanism can move forward or backward.

[0056] It is understandable that the minimum step distance of the inchworm mechanism is the distance that the inchworm mechanism can move by switching the state of the first joint component 14.

[0057] In some embodiments, the inchworm mechanism based on magnetorheology and passive joints further includes a second joint assembly 4, which includes a fourth link 41, a fifth link 42, and a sixth link 43. The first end of the fourth link 41 is hinged to the second end of the push rod 12, the second end of the fourth link 41 is hinged to the first ends of the fifth link 42 and the first ends of the sixth link 43, the second end of the fifth link 42 is hinged to the first end of the rod body 22, and the second end of the sixth link 43 is hinged to the other end of the second piston rod 232.

[0058] The embodiments of the present invention extend the motion trajectory by setting a second joint component 4, which can adapt to complex working environments such as curved pipes and irregular narrow spaces. Moreover, the extension does not change the core working principle of the inchworm mechanism, the structural modification is easy, and it is convenient for later upgrades and optimizations.

[0059] Specifically, such as Figures 3-4 As shown, the front end of the fourth link 41 is hinged to the rear end of the push rod 12, the rear end of the fourth link 41 is hinged to the front ends of the fifth link 42 and the sixth link 43, the rear end of the fifth link 42 is hinged to the front end of the rod body 22, and the rear end of the sixth link 43 is hinged to the other end of the second piston rod 232. Through the linkage of the fourth link 41, the fifth link 42, and the sixth link 43, and the coordinated linkage of the first link 141, the second link 142, and the third link 143, the movement trajectory of the rod body 22 and the second piston assembly 23 can be changed, enabling the inchworm mechanism to adapt to more complex movements and more complex working environments such as curved pipes and irregular narrow spaces, thereby improving the movement flexibility and operational adaptability of the inchworm mechanism. The second joint assembly 4 has the same structure and linkage method as the first joint assembly 14, and will not be described in detail here.

[0060] Optionally, there are two fourth links 41, two fifth links 42, and two sixth links 43. The two fourth links 41 are arranged symmetrically in the vertical direction, the two fifth links 42 are arranged symmetrically in the vertical direction, and the two sixth links 43 are arranged symmetrically in the vertical direction.

[0061] By reversing the overall arrangement of the joint components, the electromagnetic push-pull rod drives the reversed linkage in coordinated action, and in conjunction with the stiffness switching of the magnetorheological medium, the grasping function is achieved. By converting the control logic of the magnetorheological medium on the movement step distance into control of the grasping force, the overall arrangement of the first joint component 14 or the second joint component 4 is reversed, while maintaining the connection method of the electromagnetic push-pull rod, the magnetorheological damper, and the magnetorheological medium. The electromagnetic push-pull rod provides power to drive the reversed first joint component 14 or the second joint component 4 in coordinated action, adjusting the position of the rod 22 of the magnetorheological damper, and determining the opening and closing of the grasping end in conjunction with external magnetic field control. The gripping force can be infinitely adjusted by controlling the external magnetic field strength to change the stiffness of the magnetorheological medium, adapting to the characteristics of the target object. When gripping the target object, the magnetorheological medium at the corresponding link of the gripping end switches from weak to strong stiffness by applying a saturated external magnetic field, fixing the gripping end component. The reverse creeping motion of the joints then clamps and stably grips the target object, with the gripping force precisely controlled by the magnetic field strength. When releasing the target object, the magnetorheological medium switches from strong to weak stiffness by weakening the external magnetic field, allowing the gripping end component to return to its elastic state. The joint linkage then opens the gripping end, completing the object release. By adjusting the external magnetic field strength to change the stiffness of the magnetorheological medium, the gripping force can be infinitely adjusted to adapt to target objects of different weights and materials. During gripping, the magnetorheological medium at the corresponding link switches to high stiffness, fixing the gripping end component and clamping the target object through the reverse creep linkage of the joint assembly; during release, the magnetorheological medium switches to low stiffness, the gripping end component resumes movement, and the object is released.

[0062] This invention, through the reverse arrangement of joint components, transforms the step control logic of the magnetorheological medium into gripping force control, enabling the inchworm mechanism to quickly switch from movement to gripping function. Furthermore, the gripping force can be steplessly adjusted by the external magnetic field strength to adapt to different objects. The inchworm mechanism has both movement and gripping capabilities, greatly expanding the applicable scenarios of the inchworm mechanism and reducing the investment cost of the equipment.

[0063] This invention, through the timing control of an external magnetic field on the stiffness of the magnetorheological medium within the first cylinder 131 and the second cylinder 231, combined with the coordinated linkage of the first joint assembly 14, achieves alternating movement of the two piston assemblies, simulating the inchworm's undulating motion to drive the inchworm mechanism forward or backward. Utilizing the cooperation of the push rod 12, the rod 22, and the magnetorheological medium within the second frame 21, combined with magnetic field control, the rod 22 can stop at any position throughout its full stroke within the second frame 21, achieving stepless speed adjustment of the step distance. The first joint assembly 14 ensures the minimum step distance, enabling switching between micro-movement, slow walking, and fast walking movement modes. By reversing the arrangement of the joint assemblies, the control logic of the magnetorheological medium on the step distance is transformed into control of the gripping force. Combined with the stiffness switching of the power drive and magnetic field control, the inchworm mechanism can switch to a gripping function, enabling the gripping and release of target objects. The combination of stiffness switching between the push rod 12 and the magnetorheological medium, combined with the movement of the first joint assembly 14, further enriches the operating modes of the inchworm mechanism.

[0064] This invention achieves stepless speed adjustment of the step distance through the magnetic field control characteristics of the magnetorheological damper and the magnetorheological medium within the second frame 21. The first joint assembly 14 ensures the minimum step distance, enabling three movement modes: micro-movement, slow walking, and fast walking, thus enriching the movement modes. By switching the stiffness of the magnetorheological medium within the cylinder and the state switching of the first joint assembly 14, the inchworm mechanism can move forward, backward, and stop at a fixed point, further enriching the operation modes and meeting the requirements of high precision and high efficiency, adapting to different working conditions. Moreover, the magnetorheological medium has the characteristics of controllable fluidity and precise magnetic field stiffness control, improving the stability of the inchworm mechanism during movement, ensuring controllable positional accuracy, and making it suitable for confined spaces and precision operations. Precise control is achieved through the electronic control system, with fast response speed, simple operation, and easy integration into automated operation systems for unmanned operation.

[0065] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0066] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0067] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0068] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0069] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0070] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An inchworm mechanism based on magnetorheology and passive joints, characterized in that, include: A first pushing assembly, the first pushing assembly including a first frame and a push rod, at least a portion of the push rod being disposed within the first frame and the push rod being movable relative to the first frame in a first direction; The second pushing assembly includes a second frame and a rod. The second frame and the first frame are arranged at a distance in the first direction. The first end of the rod is connected to the second end of the push rod. The second end of the rod extends into the second frame. The second frame is filled with a variable stiffness medium. The stiffness of the variable stiffness medium is adjustable to achieve stepless locking of the rod in the second frame. The first pushing assembly further includes a first piston assembly, which includes a first cylinder and a first piston rod. The first cylinder is disposed on the first frame and is movable relative to the first frame along the first direction. One end of the first piston rod is movably disposed on the first cylinder, such that the other end of the first piston rod abuts against or separates from the inner wall surface of the mounting space. The second pushing assembly further includes a second piston assembly, which includes a second cylinder and a second piston rod. The second cylinder is disposed on the second frame and is movable relative to the second frame along the first direction. One end of the second piston rod is movably disposed on the second cylinder so that the other end of the second piston rod abuts against or separates from the inner wall surface of the mounting space. Both the first cylinder and the second cylinder are filled with a variable stiffness medium; The first pushing assembly further includes a first joint assembly, which includes a first link, a second link, and a third link. The first end of the first link is hinged to the end of the first frame away from the second frame. The second end of the first link is hinged to the first end of the second link and the first end of the third link. The second end of the second link is hinged to the first end of the push rod. The second end of the third link is hinged to the other end of the first piston rod.

2. The inchworm mechanism based on magnetorheology and passive joints according to claim 1, characterized in that, There are at least two first piston assemblies, which are arranged circumferentially spaced apart in the first frame, and the axial direction of the first piston rod is orthogonal to the first direction. The second piston assembly comprises at least two, and the at least two second piston assemblies are arranged circumferentially on the second frame, with the axis of the second piston rod being orthogonal to the first direction.

3. The inchworm mechanism based on magnetorheology and passive joints according to claim 1, characterized in that, When the variable stiffness medium inside the cylinder is at the first stiffness, the piston rod abuts against the inner wall of the mounting space. When the variable stiffness medium inside the cylinder is at the second stiffness, the piston rod separates from the inner wall of the mounting space, and the second stiffness is less than the first stiffness.

4. The inchworm mechanism based on magnetorheology and passive joints according to claim 3, characterized in that, There are two of each of the first link, the second link, and the third link. The two first links are symmetrically arranged in a second direction orthogonal to the first direction, the two second links are symmetrically arranged in the second direction, and the two third links are symmetrically arranged in the second direction.

5. The inchworm mechanism based on magnetorheology and passive joints according to claim 4, characterized in that, The first joint assembly has a switchable first state and a second state. In the first state, the first link and the third link are substantially parallel. In the second state, the hinge joint between the first link and the third link moves in a direction close to the first frame to form an angle between the first link and the third link. When switching from the first state to the second state, the variable stiffness medium in the first cylinder has a second stiffness, and the variable stiffness medium in the second cylinder has a first stiffness. The third connecting rod drives the first piston assembly to move relative to the first frame in the first direction away from the second piston assembly. The second connecting rod applies a force to the push rod in the direction toward the rod body, causing the first frame to move away from the second frame under the reaction force of the rod body. When switching from the second state to the first state, the variable stiffness medium in the first cylinder has a first stiffness, the variable stiffness medium in the second cylinder has a second stiffness, the first connecting rod drives the first frame to move away from the second frame, the second connecting rod drives the push rod to move away from the rod in the first direction, and the push rod drives the second pushing assembly to move closer to the first frame.

6. The inchworm mechanism based on magnetorheology and passive joints according to claim 5, characterized in that, The variable stiffness medium in the first cylinder has a first stiffness, and the variable stiffness medium in the second cylinder has a second stiffness. When switching from the first state to the second state, the first connecting rod drives the first frame to move in the direction toward the second frame, and the second connecting rod pushes the push rod to move in the direction toward the second frame to push the second pushing assembly to move in the direction away from the first frame. The variable stiffness medium in the first cylinder is of the second stiffness, and the variable stiffness medium in the second cylinder is of the first stiffness. When switching from the second state to the first state, the second connecting rod applies a force to the push rod in a direction away from the rod body, so that the first frame moves in a direction closer to the second frame body under the reaction force of the rod body. The third connecting rod drives the first piston assembly to move in a direction closer to the second piston assembly.

7. The inchworm mechanism based on magnetorheology and passive joints according to claim 1, characterized in that, It also includes a second joint assembly, which includes a fourth link, a fifth link, and a sixth link. The first end of the fourth link is hinged to the second end of the push rod, the second end of the fourth link is hinged to the first ends of the fifth link and the first ends of the sixth link, the second end of the fifth link is hinged to the first end of the rod body, and the second end of the sixth link is hinged to the other end of the second piston rod.

8. The inchworm mechanism based on magnetorheology and passive joint according to any one of claims 1-7, characterized in that, The variable stiffness medium includes a magnetorheological medium. The second frame and the rod constitute a magnetorheological damper. The damping force of the magnetorheological medium under the action of a magnetic field is adjustable to achieve stepless locking of the rod.

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