Passive two-degree-of-freedom magnetic foot

Abstract

The invention belongs to the technical field of robots, and provides a passive two-degree-of-freedom magnetic foot which comprises a shell I, a shell II and a magnetic module. The magnetic module is connected with the shell II, the magnetic module can rotate relative to the shell II, the shell II is connected with the shell I, the shell II can rotate relative to the shell I, and the axis, rotating relative to the shell II, of the magnetic module is perpendicular to the axis, rotating relative to the shell I, of the shell II; an electric permanent magnet and a strong magnet are arranged between the two magnetizers and are arranged side by side up and down, a coil is wound on the outer surface of the electric permanent magnet, and the electric permanent magnet is configured to be applied with pulse current to change the magnetic force direction, so that the magnetic module is in an external adsorption or external separation state. Two-degree-of-freedom movement is achieved, the magnetic foot can automatically adapt to the surface of the pipe wall in various poses, and therefore the adsorption performance and engineering practicability are improved while structural simplicity and functionality are considered.

Description

Technical Field

[0001] This invention relates to a robot foot, specifically a passive two-degree-of-freedom magnetic foot, belonging to the field of robotics technology. Background Technology

[0002] Traditional magnetic attraction mechanisms typically use permanent magnets. While these magnets have strong attraction forces, they are difficult to detach from. Electromagnets are also used, which can effectively control attraction and detachment, but consume a lot of power and cannot meet the requirements for low energy consumption. Other methods use electro-permanent magnet materials to achieve magnetic attraction. These materials have lower coercivity and can change the direction of the magnetic force by winding coils and applying pulsed currents in different directions. However, the magnetic energy product of these materials is not very large, resulting in insufficient magnetic force. To achieve effective attraction of the magnetic foot to the tube wall in different positions, existing magnetic foot designs on the market have two main limitations: one type of structure has no degrees of freedom, resulting in insufficient flexibility when adapting to complex curved surfaces; the other type achieves active degrees of freedom through motor drive, which improves adaptability but significantly increases system cost and control complexity.

[0003] In summary, how to automatically adapt to complex curved surfaces and reduce control complexity is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a passive two-degree-of-freedom magnetic foot. This magnetic foot achieves two passive degrees of freedom by introducing a combination of passive joints and torsion springs, enabling the magnetic foot to automatically adapt to the tube wall surface in various positions and possessing a self-resetting function. Thus, while maintaining structural simplicity and functionality, it improves adsorption performance and engineering practicality.

[0005] A passive two-degree-of-freedom magnetic foot comprises a shell I, a shell II, and a magnetic module;

[0006] The magnetic module is connected to housing II, and the magnetic module can rotate relative to housing II.

[0007] Shell II is connected to shell I, and shell II can rotate relative to shell I.

[0008] The axis of rotation of the magnetic module relative to housing II is perpendicular to the axis of rotation of housing II relative to housing I;

[0009] Each magnetic module includes an electro-permanent magnet, a strong magnet, a coil, and two magnetic conductors; the electro-permanent magnet and the strong magnet are arranged between the two magnetic conductors, and the electro-permanent magnet and the strong magnet are arranged side by side, one above the other. The outer surface of the electro-permanent magnet is wound with a coil. The electro-permanent magnet is configured such that the direction of the magnetic force of the electro-permanent magnet can be changed by applying a pulse current, so that the magnetic module is in a state of adsorption or detachment from the outside.

[0010] Furthermore, the electro-permanent magnet is an AlNiCo5 magnet.

[0011] Furthermore, the strong magnet is an NdFeB magnet.

[0012] Furthermore, the magnetic conductor is made of electrical pure iron.

[0013] Furthermore, the housing II includes a frame, two fasteners and two torsion springs I; the two fasteners are disposed on opposite sides of the frame, the fasteners are connected to the magnetic module, the fasteners have a shaft I, the shaft I is rotatably disposed on the frame, the torsion springs I are disposed on the shaft I, and the two torsion arms of the torsion springs I abut against the fasteners and the frame respectively.

[0014] Furthermore, the housing II includes a torsion spring II, and the housing II has a shaft II rotatably disposed on...

[0015] Housing I and torsion spring II are disposed on shaft II, and the two torsion arms of torsion spring II abut against housing II and housing I1 respectively.

[0016] The advantages of this application compared to the prior art are:

[0017] This application achieves two passive degrees of freedom by introducing a combination mechanism of passive joints and torsion springs, enabling the magnetic module and magnetic feet to automatically adapt to the tube wall surface in various positions and have a self-resetting function. Thus, while taking into account the simplicity of the structure and functionality, it improves the adsorption performance and engineering practicality.

[0018] The magnetic feet of this application can be used in wall-climbing robots to enable the robot to adhere to and climb walls with different curvatures. Attached Figure Description

[0019] Figure 1 A three-dimensional diagram of a passive two-degree-of-freedom magnetic foot;

[0020] Figure 2 A front view of a passive two-degree-of-freedom magnetic foot;

[0021] Figure 3 This is a front sectional view of a passive two-degree-of-freedom magnetic foot;

[0022] Figure 4 This is a 3D view of the magnetic module;

[0023] Figure 5 This is a perspective view of shell II;

[0024] Figure 6 This is a schematic diagram showing the connection between the magnetic module and housing II;

[0025] Figure 7 This is a schematic diagram of the fixing component and its connection with torsion spring I;

[0026] Figure 8 This is a schematic diagram of the state of an object adsorbed by a two-degree-of-freedom magnetic foot.

[0027] Figure 9 This is a schematic diagram of a two-degree-of-freedom magnetic foot detached from an object.

[0028] Figure 10 This is a three-dimensional simulation diagram of the parallel adsorption and detachment of the steel pipe in the embodiment;

[0029] Figure 11 This is a simulation diagram of steel pipe adsorption in the embodiment;

[0030] Figure 12 This is a simulation diagram of the steel pipe detaching in the embodiment;

[0031] Figure 13 This is a three-dimensional simulation diagram of the parallel adsorption and detachment of the steel pipe in the embodiment;

[0032] Figure 14 This is a simulation diagram of steel plate adsorption and detachment in the embodiment;

[0033] Figure 15 This is a simulation diagram of the vertical adsorption and detachment of the steel pipe in the embodiment.

[0034] In the diagram: 1. Shell I, 2. Shell II, 21. Frame, 22. Fixing component, 23. Torsion spring I, 24. Torsion spring II, 221. Shaft I, 211. Shaft II, 3. Magnetic module, 31. Electro-permanent magnet, 32. Strong magnet, 33. Coil, 34. Magnetic conductor. Detailed Implementation

[0035] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. Unless otherwise stated, the technical or scientific terms used in this application have the ordinary meaning as understood by those skilled in the art.

[0036] Reference Figure 1 and Figure 2 A passive two-degree-of-freedom magnetic foot according to this embodiment includes a housing I1, a housing II2, and a magnetic module 3;

[0037] Magnetic module 3 is connected to housing II2, and magnetic module 3 can rotate relative to housing II2;

[0038] Housing II2 is connected to housing I1, and housing II2 can rotate relative to housing I1;

[0039] The axis of rotation of magnetic module 3 relative to housing II2 is perpendicular to the axis of rotation of housing II2 relative to housing I1;

[0040] Reference Figure 3 and Figure 4Each magnetic module 3 includes an electro-permanent magnet 31, a strong magnet 32, a coil 33, and two magnetic conductors 34. The electro-permanent magnet 31 and the strong magnet 32 ​​are arranged between the two magnetic conductors 34, and the electro-permanent magnet 31 and the strong magnet 32 ​​are arranged side by side. A coil 23 is wound on the outer surface of the electro-permanent magnet 31. The coil 23 is configured to change the direction of the magnetic force of the electro-permanent magnet 31 when a pulse current is applied, so that the magnetic module 3 is in an external adsorption or external detachment state, realizing the switching between magnetic foot adsorption and release states.

[0041] Preferably, the electro-permanent magnet 21 is an AlNiCo5 magnet.

[0042] When coil 33 is connected to a pulse current, it changes the direction of the magnetic force of AlNiCo5, so that the magnetic module 2 is in a state of external adsorption or external detachment, thereby changing the state of magnetic foot adsorption or detachment.

[0043] Preferably, the strong magnet 22 is an NdFeB magnet. For example, it includes, but is not limited to, NdFeB52 or NdFeB42.

[0044] The specific form of the two-degree-of-freedom design in this embodiment is as follows:

[0045] Reference Figures 5-7 The housing II2 includes a frame 21, two fasteners 22 and two torsion springs I23;

[0046] Two fasteners 22 are disposed on opposite sides of the frame 21. The fasteners 22 are connected to the magnetic module 3. The fasteners 22 have a shaft I221, which is rotatably disposed on the frame 21. A torsion spring I23 is disposed on the shaft I221, and the two torsion arms of the torsion spring I23 abut against the fasteners 22 and the frame 21 respectively.

[0047] In this embodiment, the first degree of freedom is achieved by introducing a combination mechanism of passive joint and torsion spring I, so that the magnetic module 3 and magnetic foot can automatically adapt to the tube wall surface in various poses, such as the rotation of the magnetic module 3 relative to the shell II2 at axis I221.

[0048] Reference Figures 5-7 The housing II2 includes a torsion spring II24 and has a shaft II211, which is rotatably disposed on the housing I1. The torsion spring II24 is disposed on the shaft II211, and the two torsion arms of the torsion spring II24 abut against the housing II2 and the housing I1 respectively.

[0049] In this embodiment, a second degree of freedom is achieved by introducing a combination mechanism of passive joint and torsion spring II, enabling the magnetic module 3 and magnetic foot to automatically adapt to the tube wall surface in various poses, such as the rotation of the housing 2II and the magnetic module 3 relative to the housing I1 at axis II211.

[0050] The above implementation scheme achieves two passive degrees of freedom by introducing a combination mechanism of passive joints and torsion springs, enabling the magnetic foot to automatically adapt to the tube wall surface in various positions and possess a self-resetting function. This improves adsorption performance and engineering practicality while taking into account both structural simplicity and functionality.

[0051] Preferably, refer to Figure 7 The housing I1 consists of a pair of right-angled plates 11, and the shaft II211 is rotatably mounted on the right-angled plates 11. The two torsion arms of the torsion spring II24 abut against the housing II2 and the right-angled plates 11 respectively.

[0052] The housing I1 uses a pair of right-angle plates, which are easy to connect and disassemble. The tops of the two right-angle plates 11 are connected by bolts and nuts. The housing I1 is in the shape of an "]" with the opening facing down. This configuration covers the magnetic module 3, which greatly facilitates the realization of two passive degrees of freedom.

[0053] Each of the magnetic conductors 34 has a wear-resistant foot pad mounted on its lower surface. For example, the wear-resistant foot pad is made of magnetorheological elastomer, which gives the foot pad a higher coefficient of friction, as shown by the formula f=u×F. n It can be seen that the greater the coefficient of friction, the greater the frictional force of the magnetic foot in the tangential direction.

[0054] The application scenarios and working mechanism of this application are described below with examples.

[0055] Figure 8 The blue arrows indicate the N→S polarity direction of the electro-permanent magnet 31 (e.g., AlNiCo5 magnet) and the strong magnet 32, and the orange line indicates the direction of the magnetic conductor.

[0056] Figure 8 The display shows the magnetic foot detached state: For a single magnetic module 3, the polarity direction of the electro-permanent magnet 31, which is an AlNiCo5 magnet, is shown in the figure (N→S polarity direction). At this time, the polarity directions of the electro-permanent magnet 31 and the strong magnet 32 ​​are opposite. This polarity direction causes most of the magnetic field lines (orange lines) to be distributed inside the magnetic foot, making it appear externally that the magnetic foot has no magnetism.

[0057] Figure 9 The magnetic adsorption state is shown as follows: For a single magnetic module 3, the magnetic direction of AlNiCo5 is changed by passing a pulse current. The polarity direction of the electro-permanent magnet 31 is the same as that of the AlNiCo5 magnet (N→S polarity direction). At this time, the polarity directions of the electro-permanent magnet 31 and the strong magnet 32 ​​are the same. Most of the magnetic lines (orange lines) can pass through the wall surface that is being adsorbed, and the external state is adsorption.

[0058] Figure 10 This demonstrates a simulation result from Ansys Maxwell: the proposed method is applied to parallel adsorption and detachment in a 200mm diameter steel pipe. Figure 11 yes Figure 10 The simulation diagram of the adsorption state shows that in this implementation scheme, the magnetic wires enter the adsorbed surface along the iron core downwards. It can be seen that most of the magnetic wires enter the adsorbed object to generate magnetic force, which can generate a force of 1200N. Figure 12 yes Figure 10 The simulation diagram of the detached state shows that most of the magnetic wires are inside the magnetic foot structure and do not generate much magnetic force externally. The simulation result is only 0.08N.

[0059] Figure 13 The second simulation result from Ansys Maxwell is presented: the proposed scheme is applied to the parallel adsorption and detachment of a 400mm diameter steel pipe. In the adsorption state, most of the magnetic wires enter the adsorbed object and generate magnetic force, producing a force of 1254N; in the detachment state, most of the magnetic wires are found inside the magnetic foot structure, generating virtually no magnetic force on the outside, with a simulation result of only 1.6N.

[0060] Figure 14 The third simulation result from Ansys Maxwell is shown: the proposed scheme is applied to the adsorption and detachment of a 5mm thick steel plate. In the adsorption state, most of the magnetic wires enter the adsorbed object and generate magnetic force, which can generate a force of 1055N. In the detachment state, most of the magnetic wires are seen inside the magnetic foot structure and generate almost no magnetic force to the outside. The simulation result is only 31N.

[0061] Figure 15 The fourth simulation result from Ansys Maxwell is presented: the proposed scheme is applied to the vertical adsorption and detachment of a 400mm diameter steel pipe. In the adsorption state, most of the magnetic wires enter the adsorbed object and generate magnetic force, producing a force of 457N; in the detachment state, most of the magnetic wires are inside the magnetic foot structure and generate almost no magnetic force to the outside, with a simulation result of only 29N.

[0062] In the above implementation scheme, 100 turns of enameled wire with a diameter of 0.8 mm are wound into an electromagnetic coil, and a pulse current with a duration of 5 ms is applied under a voltage of 24V.

[0063] The magnetic applications of the above implementation scheme are as follows: it can be used as the foot of a wall-climbing robot, such as a legged wall-climbing robot, to help the robot climb walls with different curvatures; it can also be used as a flexible magnetic gripper to grasp parts with different curvatures.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions created by the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions created by the present invention without departing from the essence and scope of the technical solutions created by the present invention.

Claims

1. A passive two-degree-of-freedom magnetic foot, characterized in that: It includes housing I (1), housing II (2) and magnetic module (3); The magnetic module (3) is connected to the housing II (2), and the magnetic module (3) can rotate relative to the housing II (2); the housing II (2) is connected to the housing I (1), and the housing II (2) can rotate relative to the housing I (1); the axis of rotation of the magnetic module (3) relative to the housing II (2) is perpendicular to the axis of rotation of the housing II (2) relative to the housing I (1); Each magnetic module (3) includes an electro-permanent magnet (31), a strong magnet (32), a coil (33), and two magnetic conductors (34); the electro-permanent magnet (31) and the strong magnet (32) are arranged between the two magnetic conductors (34), and the electro-permanent magnet (31) and the strong magnet (32) are arranged side by side, one above the other. The outer surface of the electro-permanent magnet (31) is wound with a coil (33). The electro-permanent magnet (31) is configured to change the direction of its magnetic force when a pulse current is applied, so that the magnetic module (3) is in a state of adsorption or detachment from the outside.

2. The passive two-degree-of-freedom magnetic foot according to claim 1, characterized in that: The electro-permanent magnet (31) is an AlNiCo5 magnet.

3. The passive two-degree-of-freedom magnetic foot according to claim 2, characterized in that: The strong magnet (32) is an NdFeB magnet.

4. The passive two-degree-of-freedom magnetic foot according to claim 1, characterized in that: The magnetic conductor (34) is electrical pure iron.

5. A passive two-degree-of-freedom magnetic foot according to claim 1, characterized in that: The housing II (2) includes a frame (21), two fasteners (22) and two torsion springs I (23); Two fasteners (22) are disposed on opposite sides of the frame (21). The fasteners (22) are connected to the magnetic module (3). The fasteners (22) have a shaft I (221), which is rotatably disposed on the frame (21). A torsion spring I (23) is disposed on the shaft I (221). The two torsion arms of the torsion spring I (23) abut against the fasteners (22) and the frame (21) respectively.

6. The passive two-degree-of-freedom magnetic foot according to claim 1, characterized in that: The housing II (2) includes a torsion spring II (24) and has a shaft II (211) which is rotatably disposed on the housing I (1). The torsion spring II (24) is disposed on the shaft II (211) and the two torsion arms of the torsion spring II (24) abut against the housing II (2) and the housing I (1) respectively.

7. A passive two-degree-of-freedom magnetic foot according to claim 6, characterized in that: The housing I (1) is a pair of right-angled plates (11) mating together. The shaft II (211) is rotatably mounted on the right-angled plate (11). The two torsion arms of the torsion spring II (24) abut against the housing II (2) and the right-angled plate (11) respectively.

8. A passive two-degree-of-freedom magnetic foot according to any one of claims 1 to 7, characterized in that: Each of the aforementioned guides The lower surface of the magnet (34) is fitted with a wear-resistant foot pad.

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