IPMC-based monorail motion drive unit, robot and working method thereof

Abstract

The present invention discloses a monorail motion drive unit based on IPMC, a robot and a working method thereof, wherein the micro robot drive is composed of at least two drive units connected in series, the robot drive unit comprises a tube body and a drive member on the tube body, the drive member is a long sheet IPMC prepared by segmenting the tubular IPMC, the two ends of the wire are respectively connected to the drive member electrode and the control device, the anti-return device is located in the tube body, after the drive member receives the signal, the long sheet IPMC will bend and deform, the robot can be contracted, extended, guided and change track, the anti-return device in the tube body can ensure the robot unidirectional movement on the monorail. The monorail motion micro robot based on IPMC proposed by the present invention relies on IPMC intelligent drive materials, has a simple structure, a small size, high mobility, is quiet and pollution-free, can be used in the fields of interventional medicine, directional detection, etc., provides new ideas and examples for the research of micro robots, and has good application prospects.

Description

Technical Field

[0001] The invention relates to the field of micro robots, and in particular to an IPMC-based monorail motion drive unit, a robot and a working method thereof. Background Art

[0002] With the development of science and technology, in the fields of biomedicine, precision processing, etc., there is an urgent need for people to develop some operating technologies that work with tiny objects or whose positions change slightly. The manifestation of this technology is the research and development and use of micro robots.

[0003] Ionic polymer metal composite (IPMC) is a new type of artificial muscle material with the advantages of low driving voltage, large bending deformation, high sensitivity and good biocompatibility. When voltage is applied on both sides of IPMC, hydrated cations migrate to the cathode, resulting in more water molecules in the cathode area, swelling and bending of IPMC towards the anode. This is the electrical actuation principle of IPMC. Due to its excellent properties, IPMC is widely used in bionic actuators, biomedicine, micro-electromechanical systems and other fields.

[0004] Scholars at home and abroad have conducted in-depth research in the field of micro-robots. Researchers from the University of California, Berkeley, proposed a six-legged crawling robot driven by shape memory alloy. However, this type of robot is relatively large and is powered by the catalytic combustion of methanol (HOOVERAM, FEARINGRS. Fast scale prototyping for folded millirobots [C] / 2008 IEEE International Conference on Robotics and Automation. May 19-23, 2008, Pasadena, CA, USA. IEEE, 2008: 886-892.). Yan Guozheng's team in China has done a lot of positive and effective work in the field of minimally invasive diagnostic and treatment equipment, and has developed a number of capsule robots with active motion mechanisms (Yan Guozheng, Chen Wenwen. Research Progress of Intestinal Endoscopic Robots [J]. Journal of Biomedical Engineering, 2015, 32(01): 214-217.). However, in general, the existing micro-robots are mostly driven by micro-motors, hydraulic drives, and memory alloys. Electrode drives are relatively large in size and have complex structures. Hydraulic drives also have the above problems and are prone to leakage. Memory alloy drives have disadvantages in control. The above technologies still have large technical barriers to use in vivo detection and other aspects.

[0005] Therefore, the present invention proposes a monorail motion drive unit, a robot and a working method thereof based on IPMC. Summary of the invention

[0006] Based on the above technical problems, the present invention provides a monorail drive unit based on IPMC, including a first tube body and a second tube body for being mounted on the monorail, at least two driving members are connected between the first tube body and the second tube body, the number of driving members directly determines the degree of freedom of the movement guidance, the driving member is a long sheet of IPMC for receiving electrical signals to bend and deform, and the first tube body and the second tube body are both provided with a non-return structure for providing resistance when the driving unit moves.

[0007] Preferably, the long sheet IPMC is cut from the same tubular IPMC.

[0008] Preferably, the positive and negative electrodes at both ends of the driving member are connected to the control device through wires respectively, and the control device and the wires are used to control the electrical signals of the driving member electrodes.

[0009] Preferably, the interior of the non-return structure is hollow cone-shaped and the outer sides are interference-connected with the interiors of the first tube body and the second tube body. The inner diameter of the small end of the non-return structure is larger than the outer diameter of the monorail, ensuring that the monorail can enter the non-return structure normally.

[0010] Preferably, an elastic friction body is provided at the end of the anti-return structure, and the friction coefficient between the elastic friction body and the monorail is greater than 0.5.

[0011] Preferably, the elastic friction body is made of a material that is elastic and has a large friction coefficient with the monorail. It may be rubber or a coating having the above properties. The elastic friction body needs to be elastic in order to have a larger contact area with the monorail and provide greater resistance. The larger friction coefficient is to prevent slipping during movement and the inability to move forward.

[0012] To achieve the above purpose, the present invention adopts intelligent driving material IPMC as a drive, avoids complex mechanical transmission structure, can realize the contraction, extension, guidance and track change of the robot in a small space, and provides a monorail motion robot based on IPMC. The monorail motion robot is composed of at least two driving units connected in series, and the length and function of the robot are determined according to the number and length of the driving units, and its working method includes the following steps:

[0013] A. Apply a negative electrical signal to the electrode on the outer surface of the driver and a positive electrical signal to the inner surface of the driver to achieve bending of the driver on the monorail and contraction of the robot;

[0014] B. All the electrode electrical signals in the above steps are reversed, the robot stretches, and moves forward.

[0015] Preferably, the working method also includes guiding movement and track-changing movement of the robot when in use:

[0016] Guided motion: applying different electrical signals to a driving member in a driving unit of the robot, the driving member undergoes bending motion in different directions to achieve the guided motion of the robot;

[0017] Track-changing motion: The drive unit at the front end of the robot guides the track, and the drive unit at the rear end of the robot contracts and moves forward to provide power.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention innovatively proposes to use the part of the tubular IPMC that has been segmented by an instrument as a driving component, and designs a monorail motion robot based on IPMC, which can be controlled by electrical signals to realize the robot's contraction and extension on the monorail, as well as guidance and track change between the monorails. Moreover, the robot has a simple structure, a small size, high maneuverability, and is quiet and pollution-free. It can be used in interventional medicine, directional detection and other fields, and provides new ideas and examples for the research of micro robots, with good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 is a structural diagram of a robot in an embodiment of the present invention;

[0021] Figure 2 is a structural diagram of a driving unit in an embodiment of the present invention;

[0022] Figure 3 is a cross-sectional view of a non-return structure in an embodiment of the present invention;

[0023] Figure 4 Schematic diagram of the structure of the robot in the extended state in an embodiment of the present invention;

[0024] In the figure: 1-first tube body; 2-first driving member; 3-second driving member; 4-third driving member; 5-fourth driving member; 6-anti-return structure; 7-second tube body; 8-third tube body; 9-elastic friction body. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] As an embodiment of the present invention, the present invention provides a single-track motion micro robot based on IPMC, such as Figure 1 and Figure 2 As shown, it includes a monorail drive unit, a wire, a non-return structure 6, and a control device, wherein the monorail drive unit includes a tube body and a drive member on the tube body, the drive member is a sheet IPMC, and its two ends are respectively connected to the tube body, and the two ends of the wire are respectively connected to the monorail drive unit electrode and the control device, and the non-return structure 6 is located inside each tube body;

[0027] In this embodiment, the robot driving unit is composed of four driving members, namely the first driving member 2, the second driving member 3, the third driving member 4 and the fourth driving member 5. The number of driving members directly determines the degree of freedom of the micro robot during motion guidance. The driving members of the same driving unit are all sheet IPMCs divided from the middle part of the same tubular IPMC. The division method here adopts precision instruments for division, and both ends of the driving member are tube bodies.

[0028] In this embodiment, the number of wires is twice the number of sheet-like driving elements, and the two ends of the wires are connected to the driving element electrodes and the control device respectively. Each sheet-like driving element has a positive and negative electrode, and the positive electrode and the negative electrode each require a control wire;

[0029] In this embodiment, the anti-return structure 6 is tubular, and can provide forward resistance for the robot when the driving member moves, similar to a person walking on the ground. The outer portion can directly cooperate with the tube body, and the cooperation is an interference fit to prevent the anti-return structure 6 from falling off. Figure 3 As shown, the inside of the anti-return structure 6 is a hollow truncated cone, and the small end thereof is buckled with an elastic friction body 9, and the internal through-hole of the elastic friction body 9 is also arranged in a truncated cone shape, so that the robot can move in a single direction and cannot move in the reverse direction. The included angle between the generatrix of the anti-return structure 6 and the axis is 15°, and the ratio of the radius of the small circle at the top to the large circle at the bottom is 1:2. At the same time, the radius of the small circle at the top is larger than the radius of the monorail, so as to ensure that the monorail can normally enter the anti-return structure 6;

[0030] The material used for the elastic friction body 9 has elasticity and a large friction coefficient with the monorail, and the friction coefficient is at least not less than 0.5. In this embodiment, rubber is used, and a coating with the above properties can also be used. The elasticity is to ensure a larger contact area, and the large friction coefficient is to prevent slipping during movement and avoid being unable to move forward. The elastic friction body 9 is in the shape of a hollow truncated cone like the anti-return structure 6, and a monorail runs through its center. The special design of the elastic friction body 9 is used, such as Figure 3 As shown, when it moves to the left on the monorail, the elastic friction body 9 is not easily deformed, and when it moves to the right on the monorail, the elastic friction body 9 is easily squeezed toward the monorail at the contact point with the monorail, so that the anti-return structure 6 cannot move in the reverse direction on the monorail and can only move in one direction on the monorail;

[0031] In this embodiment, the robot has two drive units and three tubes, namely the front end drive unit and the rear end drive unit, the first tube 1, the second tube 7 and the third tube 8, which can be controlled by the electrical signal of the control device to realize the functions of the robot such as contraction, extension, guidance and track change.

[0032] The specific functional working process is to apply positive or reverse voltage to all driving parts independently at the same time, so that they can bend forward or reverse, so as to realize the robot to complete multi-degree-of-freedom compound movements such as contraction, extension, guidance and track change. Figure 1 , elongated state see Figure 4 .

[0033] As an embodiment of the present invention, the present invention provides a working method of a monorail motion robot based on IPMC, which specifically includes the following steps:

[0034] In this embodiment, the driving voltage is 1-3V, and both DC signals and AC signals can be used as input signals. Figure 1 As shown, by applying negative electrical signals to the outer surface electrodes of all the driving parts of the micro robot and applying positive electrical signals to the inner surface electrodes at the same time, all the driving parts can be bent inwards and the robot can be contracted; on this basis, Figure 4 As shown, all the electrode electrical signals are reversed, the robot is extended, and can move forward on the monorail;

[0035] When bending guidance is required, external positive electrical signals and internal negative electrical signals are simultaneously applied to the first driving member 2 and the second driving member 3 in the front driving unit of the robot, and then opposite electrical signals are applied to the third driving member 4 and the fourth driving member 5. At this time, the driving members driven by different electrical signals bend in different directions, and the combined movement of the driving members realizes the guiding movement of the robot.

[0036] When it is necessary to change tracks, the robot's front-end drive unit is required to guide the track, and the rear-end drive unit provides forward power. When the first tube body 2 of the front-end drive unit has all reached the new monorail, it continues to guide until the second tube body 7 enters the new track. The front-end drive unit provides forward power, and the rear-end drive unit controls so that the third tube body 8 is aligned with the new monorail interface.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A monorail motion drive unit based on IPMC, comprising a first tube body (1) and a second tube body (7) for being sleeved on the monorail, characterized in that: At least two driving members are connected between the first tube body (1) and the second tube body (7), and the driving members are long sheet-shaped IPMCs for receiving electrical signals to bend and deform, and both the first tube body (1) and the second tube body (7) are provided with a non-return structure for providing resistance when the driving unit moves; the inside of the non-return structure is in a hollow truncated cone shape and the outside is interference-connected with the inside of the first tube body (1) and the second tube body (7), and the inner diameter of the small end of the non-return structure is larger than the outer diameter of the monorail; the end of the non-return structure is provided with an elastic friction body (9), and the friction coefficient between the elastic friction body (9) and the monorail is greater than 0.

5.

2. The IPMC-based monorail motion drive unit according to claim 1, characterized in that: The long sheet IPMC is cut from the same tubular IPMC.

3. The IPMC-based monorail motion drive unit according to claim 1, characterized in that: The positive and negative electrodes at both ends of the driving member are connected to the control device through wires respectively.

4. The IPMC-based monorail motion drive unit according to claim 1, characterized in that: The elastic friction body (9) is rubber.

5. A monorail motion robot based on IPMC, characterized in that: The monorail motion robot is formed by at least two driving units as claimed in claim 1 connected in series.

6. A method for operating a monorail motion robot as claimed in claim 5, characterized in that: The following steps are involved: A. Apply a negative electrical signal to the electrode on the outer surface of the driver and a positive electrical signal to the inner surface of the driver to achieve bending of the driver on the monorail and contraction of the robot; B. All the electrode electrical signals in the above steps are reversed, the robot stretches, and moves forward.

7. The working method of the monorail motion robot according to claim 6, characterized in that: Also included are: Guided motion: applying different electrical signals to a driving member in a driving unit of the robot, the driving member undergoes bending motion in different directions to achieve the guided motion of the robot; Track-changing motion: The drive unit at the front end of the robot guides the track, and the drive unit at the rear end of the robot contracts and moves forward to provide power.

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