A dual-mode magnetic control serpentine continuum robot and its preparation and driving method

Abstract

The application discloses a dual-mode magnetic control serpentine continuum robot and a preparation and driving method thereof, and relates to the field of micro robot bionics. The design comprises a head, a neck, a trunk and a tail, wherein the trunk is composed of multiple magnetic joints and multiple flexible joints. The overall structure adopts a coaxial line design, and each part is connected end to end to form a continuous whole. The head, the magnetic joint and the tail all contain magnetic substances inside and are set to different magnetization directions. Under the action of a magnetic field, the flexible joints gradually bend, and the whole forms a continuous curve shape similar to a snake. By analyzing the commonness between the organ motion and the lateral motion of snakes in nature, the uniform space magnetic field generated by an external three-dimensional Helmholtz coil is used to enable the serpentine robot to realize the organ mode and the lateral mode in a manner combining static friction and sliding friction. The realization of the application has important significance for further research in the field of micro robot bionics.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of micro robot bionics, in particular to a dual-mode magnetic control snake-like continuum robot and its preparation and driving method. BACKGROUND

[0002] A snake-like robot is a robot designed based on bionics, which imitates the characteristics of snakes in shape and movement, and can move and explore flexibly in narrow and irregular environments, and adapt to different environments and tasks through autonomous control. A magnetic control snake-like continuum robot is a micro robot that uses magnetic control technology to achieve movement, composed of multiple continuous joints connected together, and controls the movement of the body through the interaction between the built-in magnetic material and the external magnetic field, with the advantages of high flexibility, strong adaptability, and simple operation.

[0003] Current snake-like robot research is still focused on rigid driving range, mainly driven by traditional motors, achieving large torque and simple control. Since rigid driving is difficult to realize the miniaturization of the robot, researchers usually explore new structures, technologies, and materials to achieve lightweight robots in order to reduce the weight of the robot. Published patent application CN202211470453.1 discloses a modular snake-like robot, two mechanical arm modules are rotationally connected, the drive module and the transmission module are integrated inside the mechanical arm module, the structure is compact, and the structural size is reduced under the premise of realizing stable movement. Published patent application CN202210520499.3 discloses a rope-driven vertebral structure snake-like robot, the mechanical arm uses a flexible central rod and a vertebral structure joint, has multiple degrees of freedom and good flexibility, and can shuttle in a narrow and closed environment. Published patent CN201922176268.1 discloses an electrically controlled shape memory alloy wire driven snake-like robot, each joint on the robot is connected to four memory alloy wires, the electric control device signals are transmitted to the memory alloy wires, then the joints are actuated, and the robot is driven by the memory alloy wires, reducing the weight of the robot itself.

[0004] Although the structure of the snake-like robot has gradually improved, there are still problems such as large volume of the driving device, large space occupied by the internal rigid mechanical arm unit and joints, and inability to play an advantage in some narrow and restricted spaces, so the future development of snake-like robots needs to be miniaturized, lightweight, flexible, and cable-free.

[0005] The disclosed patent application CN202110712174.0 discloses a micro magnetic control robot, which is provided with a metal oxide layer, a magnetic metal layer and a metal organic framework layer arranged in sequence, and can carry drugs in a narrow environment. The disclosed patent application CN202211321049.8 discloses a magnetic control micro carrier robot, which is provided with a cavity structure in the main body for drug loading, transportation and release. Although the existing magnetic control micro robot can realize magnetic control movement and drug transportation, it still has problems of complex structure, high manufacturing difficulty and single movement mode in a complex environment. Therefore, it is necessary to realize multi-mode movement of the magnetic control snake-shaped continuum robot through simple external magnetic field control and optimized internal structure design. SUMMARY

[0006] The purpose of the present application is to provide a magnetic control snake-shaped continuum robot capable of realizing two kinds of movement of organ mode and lateral mode by utilizing an external uniform spatial magnetic field.

[0007] Another purpose of the present application is to provide a preparation method of the magnetic control snake-shaped continuum robot.

[0008] Still another purpose of the present application is to provide a driving method for driving the magnetic control snake-shaped continuum robot to realize double-mode movement.

[0009] To this end, the technical solution of the present application is as follows:

[0010] A magnetic control snake-shaped continuum robot comprises a head (1), a neck (2), a trunk (3) and a tail (4). The snake-shaped robot structure adopts a coaxial design, and the head (1), the neck (2), the trunk (3) and the tail (4) are sequentially connected to form a continuous whole.

[0011] Further, the trunk (3) of the magnetic control snake-shaped continuum robot further comprises a plurality of magnetic joints (3-A1, 3-A2, 3-A3), and adjacent magnetic joints are connected through flexible joints (3-B1, 3-B2, 3-B3).

[0012] Further, the head (1), the magnetic joint (3-A1, 3-B1, 3-C1) and the tail (4) have a set magnetization direction in space, wherein:

[0013] The magnetization direction of the head (1) is a direction of rotating about 15° counterclockwise along the cross section of the head (1); the magnetization direction of the magnetic joint (3-A1) is a direction of rotating about 170° clockwise along the cross section of the magnetic joint (3-A1); the magnetization direction of the magnetic joint (3-A2) is a direction of rotating about 10° counterclockwise along the cross section of the magnetic joint (3-A2); the magnetization direction of the magnetic joint (3-A3) is a direction of rotating about 170° clockwise along the cross section of the magnetic joint (3-A3); and the magnetization direction of the tail (4) is a direction of rotating about 5° counterclockwise along the cross section of the tail (4).

[0014] Further, the head, the magnetic joint and the tail are all uniformly mixed by volume ratio of 1:4 of Dow Corning silicone rubber and neodymium-iron-boron magnetic particles, and then vacuum suction treatment is performed, and after curing, the elastic modulus thereof is about 11.2 MPa. The neck and the flexible joint are made of Ecoflex0010 silicone rubber, and after curing at a temperature of 40°C, the elastic modulus is about 0.4 MPa.

[0015] Further, the method for preparing the magnetic control snake-like continuum robot comprises head manufacturing, neck manufacturing, trunk manufacturing and tail manufacturing.

[0016] The manufacturing method of the head, the magnetic joint in the trunk and the tail comprises: uniformly mixing Dow Corning silicone rubber and neodymium-iron-boron magnetic particles in a beaker by volume ratio of 1:4, then performing vacuum suction treatment, then pouring the treated mixture into a mold, and after curing and forming, the elastic modulus of the head, the magnetic joint and the tail is about 11.2 MPa, and finally placing the head, the magnetic joint and the tail in a magnetizer (ME-1225) according to the set magnetization direction to perform magnetization, thereby obtaining the magnetized head, the magnetized magnetic joint and the magnetized tail, and the magnetization intensity of the head, the magnetic joint and the tail is 0.3T.

[0017] The manufacturing method of the neck and the flexible joint in the trunk comprises: horizontally placing the magnetized head, the magnetic joint in the trunk and the tail according to the structural distance of the robot in a robot mold, then filling Ecoflex0010 silicone rubber to the position of the neck and the flexible joint, and curing at a temperature of 40°C, and after the Ecoflex0010 silicone rubber is cured and formed, the elastic modulus of the obtained neck and flexible joint is about 0.4 MPa, thereby completing the manufacturing of the complete magnetic control snake-like continuum robot structure.

[0018] Further, the method for driving the magnetic control snake-like continuum robot to realize double-mode movement comprises the following specific steps.

[0019] The direction and size of the uniform space magnetic field are controlled by an external three-dimensional Helmholtz coil magnetic field generating device to realize the organ mode and the lateral mode movement.

[0020] In the organ mode movement, it is divided into two movement processes, namely, a contraction process and an expansion process.

[0021] In the lateral mode movement, it is also divided into two movement processes, namely, a swinging process and a rotating process.

[0022] Compared with the prior art, the magnetic control snake-like continuum robot, the preparation method and the driving method thereof have the advantages of simple structure and preparation method and easy control. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 FIG. 1 is a structural schematic diagram of a magnetic control snake-like continuum robot with dual mode movement according to the present application;

[0024] Figure 2 Magnetization angle diagram of the magnetic control snake-like continuum robot of the present application with magnetic parts;

[0025] Figure 3 External magnetic field control signal diagram for realizing the organ mode motion of the magnetic control snake-like continuum robot of the present application;

[0026] Figure 4 External magnetic field control signal diagram for realizing the cross mode motion of the magnetic control snake-like continuum robot of the present application;

[0027] Figure 5 (a) Process diagram for realizing the organ mode motion of the magnetic control snake-like continuum robot of the present application;

[0028] Figure 5 (b) Process diagram for realizing the cross mode motion of the magnetic control snake-like continuum robot of the present application;

[0029] Figure 1 Middle: 1, head, 2, neck, 3, trunk, 4, tail,

[0030] (3-A1, 3-A2, 3-A3), magnetic joint,

[0031] (3-B1, 3-B2, 3-B3), flexible joint. DETAILED DESCRIPTION

[0032] First of all, it needs to be pointed out that the specific structure, features and advantages of the present application will be specifically described in the following example manner, however, all the descriptions are only for illustration, and should not be understood as any limitation on the present application. In addition, any single technical feature described or implied in the embodiments mentioned in the present text can still continue to be combined or deleted between these technical features (or their equivalents), so as to obtain more other embodiments of the present application which can not be directly mentioned in the present text.

[0033] As shown in Figure 1 , the magnetic control snake-like continuum robot comprises a head (1), a neck (2), a trunk (3), and a tail (4); the overall structure of the micro robot adopts a coaxial line design, and is sequentially connected from left to right in a head-to-tail order to form a continuous whole. The trunk (3) of the magnetic control snake-like continuum robot further comprises a plurality of magnetic joints (3-A1, 3-A2, 3-A3), and adjacent magnetic joints are connected through flexible joints (3-B1, 3-B2, 3-B3).

[0034] The overall size of the magnetic control snake-like continuum robot is 12mm in length, 0.3mm in width and 0.3mm in height, wherein the head, the magnetic joints and the tail are made of DuPont silicone rubber and Nd-Fe-B magnetic particles mixed uniformly at a volume ratio of 1:4, the length of the head is 1.5mm, the length of the magnetic joint (3-A1) is 2.5mm, the length of the magnetic joint (3-A2) is 1.5mm, the length of the magnetic joint (3-A3) is 1mm, and the length of the tail is 0.5mm; the neck and the flexible joints are made of Ecoflex0010 silicone rubber, the length of the neck is 1.5mm, the length of the flexible joint (3-B1) is 1.5mm, the length of the flexible joint (3-B2) is 1.5mm, and the length of the flexible joint (3-B3) is 0.5mm.

[0035] In order to bend the whole structure under the action of an external magnetic field and form a continuous curve similar to a snake, the head (1), the magnetic joints (3-A1, 3-A2, 3-A3) and the tail (4) are magnetized in different directions, as shown in Figure 2 , to achieve the required structural deformation. Specifically,

[0036] The magnetization direction of the head (1) is about 15° counterclockwise rotation along the cross section of the head (1); the magnetization direction of the magnetic joint (3-A1) is about 170° clockwise rotation along the cross section of the magnetic joint (3-A1); the magnetization direction of the magnetic joint (3-A2) is about 10° counterclockwise rotation along the cross section of the magnetic joint (3-A2); the magnetization direction of the magnetic joint (3-A3) is about 170° clockwise rotation along the cross section of the magnetic joint (3-A3); and the magnetization direction of the tail (4) is about 5° counterclockwise rotation along the cross section of the tail (4).

[0037] The magnetic control snake-like continuum robot is made of different materials, specifically,

[0038] Step one, manufacturing the head, the magnetic joints in the trunk and the tail:

[0039] The DuPont silicone rubber and the Nd-Fe-B magnetic particles with a volume ratio of 1:4 are mixed uniformly in a beaker, then vacuum suction treatment is used to remove the gas and bubbles inside the mixed liquid, to ensure the filling and uniformity of the mixed liquid in the mold, then the treated mixed liquid is slowly poured into the mold, after solidification and molding, the elastic modulus of the head, the magnetic joints and the tail is about 11.2MPa, finally the head, the magnetic joints and the tail are placed in the magnetizer (ME-1225) according to the set magnetization direction for magnetization, thereby obtaining the magnetized head, the magnetic joints and the tail, and the magnetization intensity of the head, the magnetic joints and the tail is 0.3T.

[0040] Step two, flexible joint making in neck and trunk:

[0041] The method for making flexible joint in neck and trunk is as follows: placing the magnetized head, magnetic joint in trunk and tail according to the structural distance of the robot horizontally in the robot mold, then filling Ecoflex0010 silicone rubber to the position of neck and flexible joint, and solidifying at 40℃ by heating device, after the Ecoflex0010 silicone rubber is solidified and formed, the elastic modulus of the obtained neck and flexible joint is about 0.4Mpa, thereby the structure of the magnetically controlled snake-like continuum robot is completed.

[0042] The driving method for realizing the double-mode motion of the magnetically controlled snake-like continuum robot, the control signal of which is shown in Figure 3 and Figure 4 , and is as follows:

[0043] The direction and size of the uniform space magnetic field are controlled by the external three-dimensional Helmholtz coil magnetic field generating device to realize the motion in the organ mode and the lateral mode, and the motion process is shown in Figure 5 . The horizontal plane of the robot in the space is defined as the x-y plane of the coordinate system, the free end of the head of the robot is the origin o of the coordinate system, the direction of the tail of the robot is selected as the positive direction of the x axis, and the direction perpendicular to the horizontal plane upward is selected as the positive direction of the z axis. The motion period of the double-mode motion of the robot is 2.5s.

[0044] In the organ mode motion, the robot is divided into two motion processes, i.e. the contraction process and the expansion process, and the whole snake body is like an organ, and the front half and the rear half are alternately moved forward by using the friction. Contraction process: within 0-1s, the direction of the magnetic field is-170° in the xoz plane, the size of the magnetic field linearly increases to 80Gs with time, the head (1) is anchored to the ground, and the other end is slowly lifted by relying on the static friction, the magnetic joints (3-A1, 3-A2, 3-A3) in the trunk and the tail (4) are also simultaneously moved to the anchoring point of the head (1) by the action of the magnetic field, the flexible joints (3-B1, 3-B2, 3-B3) in the neck and trunk are subjected to a moment of force and are greatly deformed, and the whole body forms two continuous sine waves with different amplitudes and periods, wherein the flexible joint (3-B1) and the tail (4) are in sliding contact with the ground in the motion and are subjected to sliding friction; expansion process: within 1-1.5s, the direction of the magnetic field is adjusted to-180° in the xoz plane, i.e. the negative direction of the x axis, and the robot is changed to be anchored to the ground by the tail (4), within 1.5-2.5s, the size of the magnetic field linearly decreases to 0Gs with time, and the head, neck and trunk move forward, wherein the head (1) and the flexible joint (3-B1) are in sliding contact with the ground and are subjected to sliding friction. The whole cycle process is shown in Figure 5(a) shows, the motion displacement is s1, the direction of the resultant friction force points to the negative direction of the x axis, i.e. the forward moving direction.

[0045] In the lateral mode motion, it is also divided into two motion processes, i.e. the swinging process and the rotating process. The whole motion process of the robot is similar to the sidewinder in the desert, which uses the friction force to bias the body to one side and push the body forward. The swinging process: within 0-1 s, the magnetic field direction is 20° in the xoz plane, the magnetic field size increases linearly with time to 80 Gs, the magnetic joint (3-A1) in the head (1) free end and the trunk part is jointly acted by the magnetic field to make the neck (2) press the ground, at the same time, the rest of the joint and the tail of the trunk part swing obliquely forward, the whole body also forms two continuous sine waves with different amplitudes and periods, but compared with the organ mode, the phase is changed, the neck (2) is in contact with the ground in the process of motion, the bending part (3-B2) is in sliding contact with the ground, and is subjected to the sliding friction force; the rotating process: within 1-1.5 s, the magnetic field direction is adjusted to 0° in the xoz plane, i.e. the positive direction of the x axis, the robot is changed to anchor the flexible joint (3-B2) in the trunk part with the ground, then within 1.5-2.5 s, the magnetic field is adjusted to rotate linearly with time to -20° in the xoy plane, at the same time, the magnetic field size decreases linearly with time to 0 Gs, the rest of the structure of the robot rotates around the anchor point to the horizontal state, in the process of motion, the neck (2) is in sliding contact with the ground, and is subjected to the sliding friction force. The whole cycle process is as shown in Figure 5 (b) shows, the motion displacement is s2, the direction of the resultant friction force points to the oblique forward moving direction.

Claims

1. A magnetically controlled snake-like continuum robot with dual-mode motion, characterized in that, Includes head (1), neck (2), trunk (3), and tail (4); The magnetically controlled snake-shaped continuous robot adopts a coaxial design, with the head (1), neck (2), torso (3), and tail (4) connected sequentially to form a continuous whole; The torso (3) also includes multiple magnetic joints (3-A1, 3-A2, 3-A3), and adjacent magnetic joints are connected by flexible joints (3-B1, 3-B2, 3-B3); The head (1), magnetic joint one (3-A1), magnetic joint two (3-A2), magnetic joint three (3-A3), and tail (4) have a set magnetization direction in space, wherein: The magnetization direction of the head (1) is approximately 15° counterclockwise along the cross-section of the head (1); the magnetization direction of magnetic joint one (3-A1) is approximately 170° clockwise along the cross-section of magnetic joint one (3-A1); the magnetization direction of magnetic joint two (3-A2) is approximately 10° counterclockwise along the cross-section of magnetic joint two (3-A2); the magnetization direction of magnetic joint three (3-A3) is approximately 170° clockwise along the cross-section of magnetic joint three (3-A3); and the magnetization direction of the tail (4) is approximately 5° counterclockwise along the cross-section of the tail (4).

2. The method for preparing the magnetically controlled snake-shaped continuum robot according to claim 1, characterized in that, The fabrication method of a magnetically controlled snake-like continuum robot includes head fabrication, neck fabrication, torso fabrication, and tail fabrication, among which: The method for manufacturing the magnetic joints in the head and torso and the tail is as follows: Dow Corning silicone rubber and neodymium iron boron magnetic particles in a volume ratio of 1:4 are mixed evenly in a beaker. Then, vacuum gas removal is used to remove gas and air bubbles from the mixture to ensure the filling and uniformity of the mixture in the mold. After that, the treated mixture is poured into the mold and cured. The elastic modulus of the head, magnetic joints and tail is about 11.2 MPa. Finally, the head, magnetic joints and tail are placed in a magnetizer according to the set magnetization direction to magnetize them, thereby obtaining the magnetized head, magnetic joints and tail. The magnetization intensity of the head, magnetic joints and tail is 0.3T. The method for fabricating the flexible joints in the neck and torso is as follows: The magnetized head, magnetic joints in the torso, and tail are placed horizontally in the robot mold according to the structural distance of the robot. Then, Ecoflex0010 silicone rubber is filled into the neck and flexible joint positions and cured at a temperature of 40°C. After the Ecoflex0010 silicone rubber is cured and formed, the elastic modulus of the neck and flexible joints is about 0.4 MPa, thus completing the fabrication of the complete magnetically controlled snake-shaped continuum robot.

3. A method for driving a magnetically controlled snake-like continuum robot as described in claim 1 to achieve dual-mode motion, characterized in that, The specific steps are as follows: By using an external three-dimensional Helmholtz coil magnetic field generator, the direction and magnitude of the uniform spatial magnetic field are controlled to achieve accordion mode and side-walking mode movement. The robot's horizontal plane is used as the xy plane of the coordinate system, the free end of the robot's head is used as the origin o of the coordinate system, the direction of the robot's tail is selected as the positive x-axis, and the direction perpendicular to the horizontal plane and upward is selected as the positive z-axis. In the accordion mode movement, there are two movement processes: contraction and extension. During the contraction process, the magnetic field direction is -170° in the xoz plane, and the magnetic field magnitude increases linearly with time to 80Gs. The free end of the head is anchored to the ground by static friction, while the other end slowly rises. The torso and tail are also simultaneously affected by the magnetic field and move towards the head anchor point by overcoming sliding friction. The entire body forms two continuous sine waves with different amplitudes and periods. During the extension process, the magnetic field direction is adjusted to -180° in the xoz plane, i.e., the negative x-axis direction, so that the tail is anchored to the ground by static friction. The magnetic field magnitude decreases linearly with time to 0Gs. The head, neck, and torso move forward horizontally by overcoming sliding friction, thus realizing the entire accordion mode movement. In the lateral movement mode, there are two motion processes: the swinging process and the rotation process. In the swinging process, the magnetic field direction is 20° in the xoz plane, and the magnetic field magnitude increases linearly to 80Gs over time. The free end of the head and the magnetic joint 1 (3-A1) in the torso are affected by the magnetic field, causing the neck to press down on the ground, so that the neck is anchored to the ground by static friction. At the same time, the remaining joints of the torso and the tail swing forward against sliding friction. The whole body also forms two continuous sine waves with different amplitudes and periods. Compared with the organ mode, the phase has changed. In the rotation process, the magnetic field direction is adjusted to 0° in the xoz plane, that is, the positive x-axis direction, so that the flexible joint 2 (3-B2) in the torso is anchored to the ground by static friction. Then, the magnetic field is adjusted to rotate linearly to -20° in the xoy plane over time, while the magnetic field magnitude decreases linearly to 0Gs over time. The rest of the robot's structure rotates around the anchor point to a horizontal state against sliding friction, thus realizing the entire lateral movement mode.

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