A biomimetic multi-stage engagement self-rebound wide stiffness magnetic control continuum robot

Abstract

The application provides a kind of bionic multi-stage engagement self-rebound wide variable stiffness magnetic control continuum robot, including magnetic variable stiffness working section, central tensioning rope, tensioning adjusting assembly and external programmable driving magnetic field generator, adjacent magnetic segment group forms "self-rebound relaxation state-weak constraint contact state-strong engagement self-locking state" in turn under different pre-tightening degree of central tensioning rope, three states correspond to different mechanical states of central local support and geometric give priority to, peripheral complementary profile gradually contact and partially engage, peripheral full engagement and continue to be compressed in axial direction, bionic geometric give priority to is used to reduce soft state stiffness lower limit;Partially engaged to form continuous adjustable intermediate stiffness state;After full engagement, continue to increase axial pre-tightening, make PDMS-based magnetic composite material produce greater compression deformation, under the joint action of the above mechanism, form wide range of stiffness adjustment capability.

Description

Technical Field

[0001] This invention relates to the field of surgical robots, and in particular to a biomimetic multi-stage meshing self-rebound wide-stiffness magnetically controlled continuum robot. Background Technology

[0002] To achieve larger joint rotation angles, existing segmental continuum robots typically require flexible connecting sections, ball joints, serpentine connectors, or other independent joint structures with a certain axial length between adjacent main segments. This connecting region occupies the effective axial length of the continuum, limiting the number of main segments and the volume of magnetic material that can be arranged within the same length. For magnetically controlled small-scale robots, when the remanent magnetization of each magnetic segment is the same or nearly identical, the total magnetic moment is closely related to the volume of magnetic material. Therefore, a longer ineffective connecting region limits the magnetic drive torque and output capacity achievable per unit length. Furthermore, existing variable stiffness continuums struggle to simultaneously achieve both "extremely low soft stiffness" and "extremely high hard stiffness" at the microscale. On one hand, to reduce soft stiffness, traditional structures often require increased joint clearances or connector lengths; on the other hand, to increase hard stiffness, contact, clamping, or locking structures are needed, easily increasing size and assembly complexity. In addition, in narrow, continuously curved tubular environments, the stiffness of the continuum robot directly affects its ability to transmit axial push loads. When the structure is in a low stiffness state, while it facilitates compliance with curved channels, it is more prone to local bending and buckling during axial push, making it difficult to effectively transmit the push displacement and axial load input from the proximal end to the distal end. Increasing structural stiffness enhances axial support and buckling resistance, thereby improving the transmission of push force at the distal end. Therefore, existing structures still need to address the balance between compliant passage capability and axial push force transmission capability. Moreover, existing solutions generally lack a multi-stage stiffening mechanism that evolves progressively from relaxation and contact to full engagement and continued compression, and rarely incorporate flexible rotation pivots, axial compression stroke, and unloading springback reset mechanisms. While being integrated into a single structure, complex three-dimensional micro-joints typically rely on precision molds, micro-assemblies, or multi-part machining, which is not conducive to low-cost mass production. Therefore, there is still a need for a wide-variable stiffness structure that can reduce soft bending resistance through simple biomimetic geometric design, form multi-stage constraints during tensioning, and further improve stiffness through continuous axial compression after full engagement. This structure can adjust between high compliance and high axial support capacity according to task requirements, adapt to bending channels while improving buckling resistance and axial load transfer capacity when pushing is required, and also has automatic springback and disengagement, miniaturization, and mass production capabilities. Summary of the Invention

[0003] (a) Technical problems to be solved To address the aforementioned problems in the prior art, this invention provides a biomimetic multi-stage meshing self-rebound wide-stiffness magnetically controlled continuum robot.

[0004] (II) Technical Solution To achieve the above objectives, the main technical solutions adopted by the present invention include: A biomimetic multi-stage meshing self-rebound wide-stiffness magnetically controlled continuum robot includes a magnetically variable stiffness working section, a central tension rope, a tension adjustment component, and an external programmable drive magnetic field generator. The magnetic variable stiffness working section includes multiple magnetic segment groups connected in series on the central tension rope. Each magnetic segment group includes two magnetic half segments. The center of each magnetic half segment has a rope hole for the central tension rope to pass through. The two magnetic half segments are arranged opposite each other, and the functional surfaces of the two half segments are located on opposite sides. A central elastic protrusion is provided on the functional surface of each magnetic half segment. Multiple peripheral protrusions and peripheral grooves are alternately arranged along the circumferential direction on the outer periphery of the functional surface. The two magnetic half segments arranged opposite each other are positioned by the interlocking of the peripheral protrusions and peripheral grooves, and their central elastic protrusions elastically abut against each other. The central tension rope is connected to the tension adjustment assembly, which controls the axial tension force of the central tension rope on the magnetic variable stiffness working section. As the axial preload increases, the adjacent magnetic segment groups gradually transition from the central elastic protrusion abutting against each other to the outer peripheral protrusion contacting and engaging with the corresponding outer peripheral groove. After full engagement, the axial preload is further increased to further compress the central elastic protrusion and / or the peripheral engagement contact area, thereby improving the equivalent stiffness of the magnetic variable stiffness working section. The externally programmable drive magnetic field generator is used to apply magnetic torque and / or magnetic force to the magnetic variable stiffness working section.

[0005] Preferably, the tension adjustment component changes the axial preload of the central tension rope, thereby altering the contact range and geometric constraint between adjacent magnetic segment groups, and thus adjusting the axial support capacity and buckling resistance of the magnetic variable stiffness working section.

[0006] Preferably, the tension adjustment assembly includes an adjustment handle, a knob, a lead screw, and a guide seat; The adjusting handle has an adjusting cavity inside, and one end of the adjusting handle is provided with an inlet pipe that communicates with the adjusting cavity. The guide seat is fixedly installed inside the adjustment cavity; The lead screw is threaded into the guide seat, one end of the lead screw is connected to the central tension rope, and the other end of the lead screw extends out of the adjustment handle and is fixedly connected to the knob.

[0007] Preferably, there are four peripheral protrusions and four peripheral grooves, which are arranged alternately along the circumferential direction.

[0008] Preferably, the outer peripheral protrusion and the outer peripheral groove are complementary surfaces that are adapted to each other. The complementary surfaces are arc surfaces, inclined surfaces, or rounded transition surfaces. The outer peripheral protrusion and the outer peripheral groove are nested and matched with each other, which can realize alignment guidance and limiting, and allow a certain amount of relative movement between the two magnetic half segments.

[0009] Preferably, the magnetic half-segment is a magnetic composite material component, and adjacent magnetic half-segments can be attracted to each other by magnetism.

[0010] Preferably, the end of the central tension rope furthest from the tension adjustment assembly is fixedly connected to an end fixing member.

[0011] (III) Beneficial Effects The beneficial effects of this invention are as follows: 1. Adjacent magnetic segments sequentially form "self-rebound relaxation state - weak constraint contact state - strong meshing self-locking state" under different pretension levels of the central tension rope. These three states correspond to different mechanical states, namely, the central local support and geometric concession as the main features, the peripheral complementary surfaces gradually contacting and partially meshing, and the peripheral fully meshing and continuing to be subjected to axial compression. The biomimetic geometric concession is used to reduce the lower limit of soft stiffness; partial meshing forms a continuously adjustable intermediate stiffness state; after full meshing, the axial pretension is further increased, causing the PDMS-based magnetic composite material to produce greater compressive deformation, and combined with the geometric constraints of the peripheral complementary surfaces, further improving the interface equivalent stiffness and the upper limit of hard stiffness, thereby forming a wide range of stiffness adjustment capabilities. 2. This invention can change the mechanical state of the magnetically controlled continuum by adjusting the pretension of the central tension rope, enabling it to switch between higher compliance and higher axial support capacity according to different operating stages. In the low stiffness state, the magnetically controlled continuum robot has better bending compliance, which is beneficial for adapting to narrow and continuously curved channels. After increasing the pretension, the contact and geometric constraints between adjacent magnetic segments are enhanced, which can improve the axial support capacity and buckling resistance of the working section, reduce the load transfer loss caused by undesired bending or buckling during axial pushing, and thus help improve the effective transfer capacity of the near-end pushing load to the far end. 3 The central elastic protrusion simultaneously serves as a flexible rotation fulcrum, effective spacing between segments, axial compression stroke, and unloading springback disengagement function. In the self-springback relaxation state, it ensures low contact area and high flexibility. During the tensioning process, it provides compression stroke for weak constraint contact and strong meshing self-locking. After the pre-tension is released, it uses its own stored elastic strain energy to automatically disengage the outer surface and restore the relaxation state, realizing the integration of joint, variable stiffness triggering and reset. 4. Reduce the axial length occupied by independent connecting components, so that more magnetic segments can be arranged within the same total length and the effective magnetic composite material volume can be increased. Under the condition that the remanent magnetization intensity of each magnetic segment is the same or basically the same and the external magnetic field conditions are the same, a larger effective magnetic volume is conducive to increasing the total magnetic moment, thereby increasing the magnetic driving torque per unit length. 5. Magnetic half-segments can be directly formed in batches from prefabricated PDMS-NdFeB magnetic composite films / sheets through laser scanning, engraving and cutting. There is no need to manufacture complex three-dimensional micro hinges. The two processed magnetic half-segments are combined with their backs facing each other and connected in series by a central tension rope. Then, the entire or segmented magnetization is performed to complete the preparation of the working section. The process chain is short and there are few parts, which is suitable for low-cost mass production of millimeter-scale structures. Attached Figure Description

[0012] Figure 1 A schematic diagram of the structure of a biomimetic multi-stage meshing self-rebound wide-stiffness magnetically controlled continuum robot. Figure 2 This is a schematic diagram of the magnetic variable stiffness working section structure; Figure 3 This is a schematic diagram showing the operating state of the magnetic variable stiffness working section. Figure 4 This is a schematic diagram of the internal structure of the tension adjustment component.

[0013] [Explanation of Labels in the Attached Image] 1. Tension adjustment assembly; 11. Adjusting handle; 12. Guide seat; 13. Lead screw; 14. Knob; 15. Inlet tube; 2. Magnetic variable stiffness working section; 21. Magnetic half-segment; 22. Outer peripheral protrusion; 23. Outer peripheral groove; 24. Central elastic protrusion; 3. External programmable drive magnetic field generator; 4. Central tension rope; 5. End fasteners. Detailed Implementation

[0014] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0015] Please refer to Figures 1 to 4 The present invention provides a biomimetic multi-stage meshing self-rebound wide variable stiffness magnetically controlled continuum robot, including a magnetic variable stiffness working section 2, a central tension rope 4, a tension adjustment component 1, and an external programmable drive magnetic field generator 3. The magnetic variable stiffness working section 2 includes multiple magnetic segment groups connected in series on the central tension rope 4. Each magnetic segment group includes two magnetic half-segments 21. The center of each magnetic half-segment 21 has a rope hole for the central tension rope 4 to pass through. The two magnetic half-segments 21 are arranged opposite to each other, and the functional surfaces of the two half-segments are located on opposite sides. A central elastic protrusion 24 is provided on the functional surface of each magnetic half-segment 21. Multiple peripheral protrusions 22 and peripheral grooves 23 are alternately arranged along the circumferential direction on the outer periphery of the functional surface. The two magnetic half-segments 21 arranged opposite to each other are positioned by the interlocking of the peripheral protrusions 22 and the peripheral grooves 23, and the central elastic protrusions 24 of the two half-segments elastically abut against each other. The central tension rope 4 is connected to the tension adjustment component 1, which is used to control the axial tension force of the central tension rope 4 on the magnetic variable stiffness working section 2. As the axial preload increases, the adjacent magnetic segment groups gradually transition from the central elastic protrusion 24 abutting against each other to the outer peripheral protrusion 22 contacting and engaging with the corresponding outer peripheral groove 23. After full engagement, the axial preload continues to increase, further compressing the central elastic protrusion 24 and / or the peripheral engagement contact area to improve the equivalent stiffness of the magnetic variable stiffness working section. The external programmable drive magnetic field generator 3 is used to apply magnetic torque and / or magnetic force to the magnetic variable stiffness working section 2.

[0016] Preferably, the tension adjustment component 1 changes the axial pretension of the central tension rope 4, thereby changing the contact range and geometric constraint between adjacent magnetic segment groups, and thus adjusting the axial support capacity and buckling resistance of the magnetic variable stiffness working section 2. The tension adjustment component 1 includes an adjustment handle 11, a knob 14, a lead screw 13, and a guide seat 12. The adjusting handle 11 has an adjusting cavity inside, and one end of the adjusting handle 11 is provided with an inlet pipe 15 that communicates with the adjusting cavity. The guide seat 12 is fixedly installed inside the adjustment cavity; The lead screw 13 is threaded into the guide seat 12. One end of the lead screw 13 is connected to the central tension rope 4, and the other end of the lead screw 13 extends out of the adjustment handle 11 and is fixedly connected to the knob 14. The outer peripheral protrusion 22 and the outer peripheral groove 23 are complementary surfaces that are adapted to each other. The complementary surfaces are arc surfaces, inclined surfaces, or rounded transition surfaces. The outer peripheral protrusion 22 and the outer peripheral groove 23 are nested together to achieve alignment guidance and limiting, and allow a certain amount of relative movement between the two magnetic half segments 21.

[0017] In use, by adjusting the axial tension force of the central tension rope 4 on the magnetic variable stiffness working section 2 through the tension adjustment component 1, the magnetic variable stiffness working section 2 can achieve switching between the following three stages: Phase 1: Self-rebound relaxation state; Under relaxed or low preload conditions, adjacent magnetic half-segments 21 are mainly in local contact through the central elastic protrusion 24. The central elastic protrusion 24 is in a naturally stretched state or undergoes slight compression deformation and serves as an integrated flexible rotation fulcrum between adjacent segments. The outer peripheral protrusion 22 and the outer peripheral groove 23 maintain sufficient geometric clearance space and do not form significant geometric constraints. The outer peripheral protrusion 22 on the inner side of the bend can enter the outer peripheral groove 23 reserved in the next segment, avoiding premature contact of the outer peripheral structure of adjacent magnetic half-segments 21 at a small tilt angle, thereby reducing the limitation of geometric interference on the further rotation of the segment. Thus, a large single-segment tilt angle can still be obtained with a low central fulcrum height and a small segment axial spacing, reducing the soft bending resistance and overall equivalent stiffness to an extremely low level and forming a highly flexible state. Second stage: Weakly constrained contact state; As the tension of the central tension rope 4 increases, the central elastic protrusion 24 gradually undergoes axial compression, the axial distance between adjacent segments decreases, the outer peripheral protrusion 22 gradually enters the corresponding outer peripheral groove 23, the peripheral complementary surfaces begin to contact and participate in load bearing, and the structure gradually enters the weakly constrained contact state from the self-rebound relaxation state. At this stage, the outer peripheral protrusion 22 and the outer peripheral groove 23 have not yet formed sufficient contact. The peripheral contact mainly restricts the tilting, torsion and lateral misalignment of adjacent segments, while still retaining a limited relative tilting capacity. As the preload further increases, the contact range, contact pressure and structural constraint degree gradually increase, enabling the robot to form an intermediate stiffness range transitioning from low stiffness to high stiffness. Third stage: Strong meshing self-locking state; After further increasing the tension of the central tension rope 4, the outer peripheral protrusion 22 and the outer peripheral groove 23 gradually reach a fully engaged state, and the peripheral complementary surfaces form a relatively complete contact and geometric constraint. After reaching full engagement, the axial preload is further increased. It is difficult for adjacent magnetic half segments 21 to continue to move axially closer by significantly increasing the engagement depth. At this time, the further applied axial load mainly causes the central elastic protrusion 241 and the peripheral engagement contact area to undergo further compression deformation. By changing the degree of axial preload, the axial support capacity and buckling resistance of the magnetically controlled continuum 2 can also be changed to adjust its axial pushing load transmission capacity in the curved channel. It should be noted that: since the segment is made of magnetic composite material with PDMS as the elastomer matrix, it has obvious nonlinear mechanical response under large compression deformation. At the same time, the lateral deformation of the outer complementary surface in the contact area forms a constraint, which further increases the contact pressure and the equivalent contact stiffness of the interface with the degree of compression. Therefore, the high stiffness under strong meshing is not only due to the geometric constraint between the protrusion and the groove, but is formed by the geometric constraint formed by full meshing and the nonlinear stiffening effect generated by continuous axial compression after meshing.

[0018] In this embodiment, the wide variable stiffness capability of the magnetic variable stiffness working section 2 robot is based on the above-mentioned multi-stage meshing mechanism. In the self-rebound relaxation state, the lower limit of soft stiffness is significantly reduced through geometric concession and central local self-recovering fulcrum. In the weak constraint contact state, the peripheral complementary surfaces gradually contact and participate in bearing, forming a continuously adjustable intermediate stiffness. In the strong meshing self-locking state, the outer peripheral protrusion 22 and the outer peripheral groove 23 first achieve full meshing and establish a strong geometric constraint. On this basis, the axial preload is further increased, so that the central elastic protrusion 24 and the peripheral meshing contact area undergo further compression deformation. PDMS-based magnetic composite materials exhibit significant nonlinear load-bearing response under large compressive strain. Meanwhile, the complementary surfaces after full meshing restrict the lateral deformation of the material, further increasing the contact pressure and the equivalent stiffness of the interface, thereby raising the upper limit of the hard state stiffness. Thus, the structure does not simply rely on increasing the traction force to continuously increase friction, but instead undergoes a multi-stage mechanical evolution process of geometric concession, gradual contact, full meshing, and continuous compression stiffening after meshing. By simultaneously lowering the lower limit of stiffness and raising the upper limit of stiffness, a large maximum stiffness / minimum stiffness ratio is formed. Furthermore, when the magnetically controlled continuum 2 is subjected to a near-end axial push load within a curved channel, its preload state can also affect the ability to transfer the axial load to the far end. Under a lower preload state, the magnetically controlled continuum 2 exhibits higher bending compliance, which is beneficial for adapting to curved channels. However, under axial push, it is more prone to undesirable bending or local buckling, causing some of the near-end input load to be converted into structural bending deformation, thus resulting in axial load transfer loss. As the tension of the central tension rope 4 increases, the contact range, contact pressure, and geometric constraint between adjacent magnetic segments increase, improving the overall stiffness, axial support capacity, and buckling resistance of the magnetically controlled continuum 2. This reduces load transfer loss caused by undesirable bending or buckling during axial push, and is beneficial for improving the effective transfer capability of the near-end axial push load to the far end. Therefore, the bending compliance and axial push load transfer capability can be adjusted by regulating the preload of the central tension rope 4 according to the channel morphology and operating stage.

[0019] When the magnetically controlled continuum 2 is placed in a tubular channel with one or more curved sections and an axial pushing load is applied from its proximal end, the magnetically controlled continuum 2 undergoes significant flexible deformation within the curved sections under low preload, resulting in a lower effective axial pushing load at the distal end. By increasing the preload of the central tension rope 4, the axial support capacity of the magnetically controlled continuum 2 is enhanced, enabling it to transmit a larger effective axial pushing load to the distal end under the same or similar channel conditions.

[0020] In this embodiment, an integrated self-rebound fulcrum design is adopted, integrating the flexible connection, rotation fulcrum, compression stroke, and springback reset functions of traditional segments with independent axial lengths into the central elastic protrusion 24. In the self-rebound relaxation state, the central elastic protrusion 24 serves as a local flexible fulcrum and determines the effective spacing between segments. During the process of entering the weak constraint contact state and the strong meshing self-locking state, it provides the axial stroke required for the peripheral surface to contact and engage step by step through its own compression. After the pre-tightening is reduced or released, the stored elastic strain energy is released, which pushes the adjacent segments to actively separate and causes the peripheral surface to disengage. Thus, there is no need for an additional independent joint or return spring that occupies a significant axial space. More magnetic segments can be arranged within the same length, and the effective volume of the magnetic composite material per unit length is increased.

[0021] In this embodiment, four of the outer peripheral protrusions 22 and four of the outer peripheral grooves 23 are provided, and the four outer peripheral protrusions 22 and four outer peripheral grooves 23 are arranged alternately along the circumferential direction.

[0022] In this embodiment, the magnetic half-segment 21 is a magnetic composite material component. Adjacent magnetic half-segments 21 are attracted by magnetism. Preferably, the magnetic half-segment 21 is first prepared as a PDMS-NdFeB magnetic composite film or magnetic composite sheet with a predetermined thickness. Then, the magnetic composite film is removed and contoured by laser scanning and laser engraving to directly form a magnetic half-segment 21 with a functional surface, a central elastic protrusion 24, an outer peripheral protrusion 22, an outer peripheral groove 23, and a rope hole. Multiple magnetic half-segments 21 can be arranged in batches on the same magnetic composite film and scanned and processed. After processing, two magnetic half-segments 21 are combined back to back and connected in series by a central tension rope 4. After assembling multiple segments, the whole or segmented magnetization can be performed to form a magnetic working segment, thereby avoiding complex three-dimensional micro hinges and precision assembly of multiple parts.

[0023] In this embodiment, the end of the central tension rope 4 away from the tension adjustment component 1 is fixedly connected to the end fixing member 5; This invention first solves the contradiction between "low stiffness and large rotation angle requiring long connecting mechanisms" in traditional segmental structures by using "bionic geometric yielding + self-rebound relaxation state". In the relaxed state, the central elastic protrusion 24 only forms a small local support area, and the outer protrusions can enter the adjacent groove area to make room for movement. This allows the joint to still have a large relative rotation angle with a very small axial pitch. Therefore, the robot can obtain lower soft stiffness and higher bending flexibility without relying on a high central pivot or a long independent connecting part.

[0024] Secondly, this invention expands the stiffness adjustment range through a multi-stage engagement mechanism. As the preload increases, the structure sequentially transitions from a self-rebounding relaxation state to a weakly constrained contact state, and then to a strongly engaged self-locking state. In the first stage, the contact load gradually expands from the central local area to the peripheral complementary surfaces. The outer peripheral protrusion 22 and the outer peripheral groove 23 gradually reach full engagement from insufficient contact, and the geometric constraint is strengthened accordingly. After reaching full engagement, the axial preload continues to increase, and the subsequent axial displacement is mainly converted into further compression of the central elastic protrusion 24 and the peripheral engagement contact area, which further increases the contact pressure and the equivalent stiffness of the interface. Thus, the structure can obtain a very low lower limit of stiffness in the relaxation state, and a higher upper limit of stiffness through continuous compression after full engagement, and obtain continuous intermediate stiffness through the weakly constrained contact state.

[0025] Meanwhile, the integrated self-rebound fulcrum of this invention concentrates flexible rotation, axial spacing, compression stroke, and unloading reset in the central elastic protrusion 24. Under low preload, it serves as the flexible rotation fulcrum; under tension, it provides axial stroke for multi-stage engagement through compression; and under unloading, it relies on its own elastic recovery to push adjacent segments apart, causing the strong engagement self-locking state to sequentially revert to the weak constraint contact state and ultimately restore the self-rebound relaxation state. Compared to additional independent joints, springs, and unlocking components, this integrated structure reduces the number of parts and axial footprint, and directly contributes to increasing the volume of magnetic material per unit length and the magnetic drive output capability.

[0026] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention's specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

[0027] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A biomimetic multi-stage meshing self-rebound wide-stiffness magnetically controlled continuum robot, characterized in that, It includes a magnetic variable stiffness working section, a central tension rope, a tension adjustment assembly, and an external programmable drive magnetic field generator; The magnetic variable stiffness working section includes multiple magnetic segment groups connected in series on the central tension rope. Each magnetic segment group includes two magnetic half segments. The center of each magnetic half segment has a rope hole for the central tension rope to pass through. The two magnetic half segments are arranged opposite each other, and the functional surfaces of the two half segments are located on opposite sides. A central elastic protrusion is provided on the functional surface of each magnetic half segment. Multiple peripheral protrusions and peripheral grooves are alternately arranged along the circumferential direction on the outer periphery of the functional surface. The two magnetic half segments arranged opposite each other are positioned by the interlocking of the peripheral protrusions and peripheral grooves, and their central elastic protrusions elastically abut against each other. The central tension rope is connected to the tension adjustment assembly, which controls the axial tension force of the central tension rope on the magnetic variable stiffness working section. As the axial preload increases, the adjacent magnetic segment groups gradually transition from the central elastic protrusion abutting against each other to the outer peripheral protrusion contacting and engaging with the corresponding outer peripheral groove. After full engagement, the axial preload is further increased to further compress the central elastic protrusion and / or the peripheral engagement contact area, thereby improving the equivalent stiffness of the magnetic variable stiffness working section. The externally programmable drive magnetic field generator is used to apply magnetic torque and / or magnetic force to the magnetic variable stiffness working section.

2. The biomimetic multi-stage meshing self-rebound wide-stiffness magnetically controlled continuum robot according to claim 1, characterized in that, The tension adjustment component changes the axial preload of the central tension rope, thereby altering the contact range and geometric constraint between adjacent magnetic segment groups, and thus adjusting the axial support capacity and buckling resistance of the magnetic variable stiffness working section.

3. The biomimetic multi-stage meshing self-rebound wide-stiffness magnetically controlled continuum robot according to claim 2, characterized in that, The tension adjustment assembly includes an adjustment handle, a knob, a lead screw, and a guide seat; The adjusting handle has an adjusting cavity inside, and one end of the adjusting handle is provided with an inlet pipe that communicates with the adjusting cavity. The guide seat is fixedly installed inside the adjustment cavity; The lead screw is threaded into the guide seat, one end of the lead screw is connected to the central tension rope, and the other end of the lead screw extends out of the adjustment handle and is fixedly connected to the knob.

4. The biomimetic multi-stage meshing self-rebound wide-stiffness magnetically controlled continuum robot according to claim 1, characterized in that, There are four outer peripheral protrusions and four outer peripheral grooves, which are arranged alternately along the circumferential direction.

5. The biomimetic multi-stage meshing self-rebound wide-stiffness magnetically controlled continuum robot according to claim 1, characterized in that, The outer peripheral protrusion and the outer peripheral groove are complementary surfaces that fit each other. The complementary surfaces are arc surfaces, inclined surfaces, or rounded transition surfaces. The outer peripheral protrusion and the outer peripheral groove are nested together to achieve alignment guidance and limiting, and allow a certain amount of relative movement between the two magnetic half segments.

6. The biomimetic multi-stage meshing self-rebound wide-stiffness magnetically controlled continuum robot according to claim 1, characterized in that, The magnetic half-segment is a magnetic composite material component, and adjacent magnetic half-segments can be attracted to each other by magnetism.

7. A biomimetic multi-stage meshing self-rebound wide-stiffness magnetically controlled continuum robot according to claim 1, characterized in that, The end of the central tension rope furthest from the tension adjustment assembly is fixedly connected to the end fixing component.

Images