Soft-bodied robot with internal and external magnetic source collaborative excitation and control method thereof

Abstract

The application discloses a kind of inner and outer magnetic source collaborative excitation type soft gripper robot and its control method, belong to magnetic control soft robot field, robot includes: catheter, the multi-arm magnetic control soft gripper of connecting catheter one end, built-in permanent magnet located in catheter interior, external magnet located in catheter exterior, multi-arm magnetic control soft gripper is located between built-in permanent magnet and external magnet;Built-in permanent magnet and the magnetic field direction of external magnet generated is opposite;Multi-arm magnetic control soft gripper includes multiple end cross section arc-shaped strip arm, each strip arm is pre-radial magnetization, and magnetization direction satisfies: under the radial magnetic field generated by built-in permanent magnet alone, the end of each strip arm is in closed state;Under the radial magnetic field generated by built-in permanent magnet and external magnet jointly, the end of each strip arm is in open state.Provides effective way for realizing non-contact removal of foreign matter in narrow, complex environment.

Description

Technical Field

[0001] This invention belongs to the field of magnetically controlled soft robots, and more specifically, relates to a soft gripper robot with coordinated internal and external magnetic source excitation and its control method. Background Technology

[0002] Grappling robots mainly refer to robots that resemble claws and have grasping capabilities. They are widely used in a wide range of applications, from large-scale industrial scenarios such as workshop transportation and express delivery sorting, to small-scale daily life scenarios such as garbage collection and drug sorting, and even micro-scale medical scenarios such as minimally invasive diagnosis and treatment and blood vessel unblocking.

[0003] Traditional gripper robots mostly employ wired electronic control, requiring external devices such as power cords to be connected to the rear of the gripper. The operation and space constraints caused by these wires can limit their functionality. Magnetic grippers, driven by magnetic fields, enable remote, non-contact wireless control, offering broader application prospects compared to wired electronic gripper robots. In particular, magnetically controlled soft gripper robots, which have emerged in recent years, possess characteristics such as large deformation capabilities, flexible contact, and strong applicability, demonstrating significant advantages in the research and application of gripper robots.

[0004] Existing magnetically controlled soft gripper robots primarily rely on external magnetic sources to control the gripper. These external magnetic sources are mainly permanent magnets and electromagnets. For external permanent magnets, control relies on human hands or robotic arms to manipulate the generated magnetic field, resulting in a relatively complex, cumbersome control method with poor responsiveness. External electromagnets require continuous external power for excitation, leading to magnet overheating issues during prolonged operation, and the direction of the external magnetic field needs flexible adjustment, further complicating control. In addition to the aforementioned problems, existing magnetically controlled soft gripper robots with a single external magnetic source must maintain a sufficiently close distance between the external magnetic source and the gripper during grasping and transport to ensure stable grip control. Once detached from the external magnetic source, they cannot maintain a continuous grip on objects, resulting in unstable gripping. Summary of the Invention

[0005] To address the shortcomings and improvement needs of existing technologies, this invention provides a soft gripper robot with coordinated internal and external magnetic source excitation and its control method. The purpose is to solve the problems faced by existing technologies that control soft gripper robots with a single external magnetic source, such as the need for continuous excitation of the external magnetic source, high control requirements, and unstable gripping.

[0006] To achieve the above objectives, according to one aspect of the present invention, a soft gripper robot with coordinated internal and external magnetic source excitation is provided, comprising: a conduit, a multi-arm magnetically controlled soft gripper connected to one end of the conduit, a built-in permanent magnet located inside the conduit, and an external magnet located outside the conduit, wherein the multi-arm magnetically controlled soft gripper is located between the built-in permanent magnet and the external magnet; the magnetic fields generated by the built-in permanent magnet and the external magnet are in opposite directions; the multi-arm magnetically controlled soft gripper includes multiple strip-shaped arms with arc-shaped end cross-sections, each of the strip-shaped arms being pre-magnetized radially, and the magnetization direction satisfies the following: under the radial magnetic field generated solely by the built-in permanent magnet, the ends of each strip-shaped arm are in a closed state; under the radial magnetic field jointly generated by the built-in permanent magnet and the external magnet, the ends of each strip-shaped arm are in an open state.

[0007] Furthermore, it also includes: a robotic arm comprising three joints and having seven degrees of freedom; the external magnet is located within the robotic arm, and the external magnet is moved by the robotic arm.

[0008] Furthermore, both the conduit and the multi-arm magnetically controlled soft gripper are made of silicone; the surface of each of the strip-shaped arms is coated with a magnetic mixture formed by permanent magnet particles and soft material.

[0009] Furthermore, the soft material is made of platinum-catalyzed silica gel, and the permanent magnet particles are made of neodymium iron boron particles; the platinum-catalyzed silica gel serves as the base solution for the neodymium iron boron particles; after the A component solution and B component solution of the platinum-catalyzed silica gel are mixed at a mass ratio of 1:1, the neodymium iron boron particles are added to form the magnetic mixture.

[0010] Furthermore, the external magnet is a permanent magnet or an electromagnet.

[0011] Furthermore, the number of the strip-shaped arms is four, and the central angle corresponding to each strip-shaped arm is 45°.

[0012] Furthermore, the outer surface of the conduit is coated with talc.

[0013] According to another aspect of the present invention, a control method for a soft gripper robot with coordinated internal and external magnetic source excitation as described above is provided, comprising: moving the soft gripper robot toward an object to be grasped until the object to be grasped is within the grasping range of the soft gripper robot; controlling an external magnet to move toward a multi-arm magnetically controlled soft gripper until the ends of each strip-shaped arm in the multi-arm magnetically controlled soft gripper are in an open state to grasp the object to be grasped; and removing the external magnet so that the ends of each strip-shaped arm are in a closed state.

[0014] In summary, the above-described technical solutions conceived in this invention can achieve the following beneficial effects:

[0015] (1) A soft gripper robot with coordinated internal and external magnetic source excitation is provided. A permanent magnet is set inside the tube and a magnet is set outside the tube. The combination of the internal permanent magnet and the external magnet can control the opening and closing of the gripper, thereby capturing and releasing objects. The operation mode is simple and can solve the problem of the difficulty in adjusting the opening and closing state of the gripper in the traditional single permanent magnet source. Under the action of the internal permanent magnet of the tube alone, the gripper can be kept in a closed state for a long time and stably, so that the captured object can be transported under the traction of the tube. This can solve the problems of the traditional single electromagnetic source gripper robot requiring continuous power supply and dynamic adjustment of magnetic field direction in complex environments. It can realize the retrieval and transportation of objects inside the tube without the need for external magnets to follow, providing a new technical approach for realizing wireless and remote drive and object manipulation of soft gripper robots in complex and narrow environments.

[0016] (2) Applying a magnetic mixture of permanent magnet particles and soft material to the surface of the multi-arm magnetically controlled soft gripper can combine the advantages of high support strength of silicone hose and high controllability of magnetic soft material, allowing the originally non-magnetic ordinary hose to have the ability to grip objects, which can solve the problem of insufficient hardness of pure magnetic soft material, so that the magnetically controlled soft gripper robot has the advantages of high strength and high controllability at the same time.

[0017] (3) Coating the outer surface of the conduit with talc powder can reduce the friction encountered by the gripper robot during its propulsion, reduce the difficulty of operating the gripper robot, and improve the gripping efficiency of the gripper robot. Attached Figure Description

[0018] Figure 1 This is a structural schematic diagram of a soft gripper robot with coordinated internal and external magnetic source excitation provided in an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of a soft gripper robot with coordinated internal and external magnetic source excitation closing under the action of a built-in permanent magnet, as provided in an embodiment of the present invention.

[0020] Figure 3 The fabrication process of the soft gripper robot with coordinated internal and external magnetic source excitation provided in the embodiments of the present invention;

[0021] Figure 4 A schematic diagram of the natural relaxation state of the soft gripper robot with coordinated internal and external magnetic source excitation provided by the present invention in a region without a magnetic field;

[0022] Figure 5 A schematic diagram of the gripping state of the soft gripper robot with internal and external magnetic source co-excitation provided by the present invention when it has a built-in permanent magnet;

[0023] Figure 6 Image recordings of the soft gripper robot with internal and external magnetic source co-excitation provided by the present invention performing a lightweight ball grasping experiment in an S-shaped tube.

[0024] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0025] 1 is a conduit, 2 is a multi-arm magnetically controlled soft gripper, 3 is a built-in permanent magnet, 4 is an external magnet, 5 is a fixing belt, 6 is a pulse magnetic field generator, 7 is a lightweight ball, and 8 is an S-shaped tube. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0027] In this invention, the terms "first," "second," etc. (if present) in the invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0028] Figure 1 This is a schematic diagram of the structure of a soft gripper robot with coordinated internal and external magnetic source excitation, provided in an embodiment of the present invention. (See also...) Figure 1 , combined Figures 2-6 This paper provides a detailed description of the soft gripper robot with coordinated internal and external magnetic source excitation in this embodiment.

[0029] The soft gripper robot with coordinated internal and external magnetic source excitation includes: a conduit 1, a multi-arm magnetically controlled soft gripper 2 connected to one end of the conduit 1, a built-in permanent magnet 3 located inside the conduit 1, and an external magnet 4 located outside the conduit 1. The multi-arm magnetically controlled soft gripper 2 is located between the built-in permanent magnet 3 and the external magnet 4.

[0030] The magnetic fields generated by the built-in permanent magnet 3 and the external magnet 4 are in opposite directions. The multi-arm magnetically controlled soft gripper 2 includes multiple strip-shaped arms with arc-shaped end cross-sections. Each strip-shaped arm is pre-magnetized radially, and the magnetization direction satisfies the following: under the radial magnetic field generated solely by the built-in permanent magnet 3, the ends of each strip-shaped arm are in a closed state; under the radial magnetic field jointly generated by the built-in permanent magnet 3 and the external magnet 4, the ends of each strip-shaped arm are in an open state. The soft gripper robot with coordinated internal and external magnetic source excitation in the open state is as follows: Figure 1 As shown, the soft gripper robot with coordinated internal and external magnetic source excitation in a closed state is as follows: Figure 2 and Figure 5As shown, the duct and multi-arm magnetically controlled soft gripper in the open state are as follows: Figure 4 As shown.

[0031] When it is necessary to grasp a target object, the built-in permanent magnet and the external magnet work together, taking advantage of the combined driving force of the external and internal magnetic sources, so that the multi-arm magnetically controlled soft gripper is in the open state to freely grasp the target object; after grasping, the external magnet is removed, and the external magnet does not work, only the built-in permanent magnet works, which can keep the multi-arm magnetically controlled soft gripper in the normally closed state without consuming electrical energy, without the need for external magnetic field control.

[0032] According to an embodiment of the present invention, the external magnet 4 is a permanent magnet or an electromagnet. Preferably, there are four strip-shaped arms, and the central angle corresponding to each strip-shaped arm is 45°. The strip-shaped arms of the multi-arm magnetically controlled soft gripper 2 are axially oriented strip structures. Preferably, the outer surface of the conduit 1 is coated with talc powder.

[0033] According to an embodiment of the present invention, the soft gripper robot with coordinated internal and external magnetic source excitation further includes: a robotic arm, which includes three joints and has seven degrees of freedom. An external magnet 4 is located inside the robotic arm, and the robotic arm moves the external magnet 4.

[0034] According to an embodiment of the present invention, both the conduit 1 and the multi-arm magnetically controlled soft gripper 2 are made of silicone; the surface of each strip-shaped arm is coated with a magnetic mixture formed of permanent magnet particles and soft material. The permanent magnet particles are, for example, neodymium iron boron particles, and the soft material is, for example, silicone, polydimethylsiloxane (PDMS), etc.

[0035] Preferably, the soft material is platinum-catalyzed silica gel, and the permanent magnet particles are neodymium iron boron (NdFeB) particles; the platinum-catalyzed silica gel serves as the base solution for the NdFeB particles. After mixing component A and component B of the platinum-catalyzed silica gel at a 1:1 mass ratio, NdFeB particles are added to form a magnetic mixture. Preferably, the volume fraction of the added NdFeB particles is 20%.

[0036] See Figure 3 The preparation process of the soft gripper robot with coordinated internal and external magnetic source excitation in this embodiment is explained with specific examples.

[0037] The first step is to cut the head of catheter 1 axially.

[0038] Specifically, the catheter 1 is made of silicone, for example, which is soft and tough. The catheter has a ring-shaped cross-section with an inner radius of 2 mm and an outer radius of 2.5 mm. The head of the catheter 1 is cut into four strip-shaped arms, each 10 mm long and with a central angle of 45°.

[0039] The second step is to mix the magnetic particles with a soft material matrix and apply it to the surface of the strip-shaped arm.

[0040] Specifically, for example, component A and component B of the silicone are mixed at a 1:1 mass ratio, and then 20% by volume of neodymium iron boron (NdFeB) particles are added. The mixture is placed in a mixer and stirred at 2000 rpm for 2 minutes, followed by degassing at 2000 rpm for 1 minute to obtain a uniform magnetic mixture. In this embodiment, considering that the same material has a better adhesion effect, platinum-catalyzed silicone is used as the base solution for the magnetic particles when manufacturing the gripper, which can enhance the adhesion of the cured magnetic soft coating to the surface of the hose.

[0041] Apply the magnetic mixture evenly to the outer, inner, and side surfaces of the four strip-shaped arms using a brush. Let it stand at room temperature for 3 hours to allow the magnetic mixture to solidify on the surface of the strip-shaped arms. Mix the magnetic particles with the soft material matrix and apply evenly to the cut sections. The multi-arm magnetically controlled soft gripper is relatively soft and easily deforms in a magnetic field.

[0042] The third step is to magnetize the multi-arm magnetically controlled soft gripper.

[0043] Specifically, during magnetization, the tip is bound by the fixing strap 5 of the restraint gripper, so that the tip is in a closed state. The multi-arm magnetically controlled soft gripper of the conduit and its end is placed at the center of the pulse magnetic field generator 6. The strip arm is saturated magnetized by the 2.7T pulse magnetic field generated by the pulse magnetic field generator 6, and the magnetization deflection angle is, for example, 10°, so that the strip arm can remain in a normally closed state under the action of the radial magnetic field.

[0044] The fourth step is to apply a layer of talcum powder to the surface of the catheter.

[0045] Fifth, the built-in permanent magnet 3 is used as an internal magnetic source and embedded in the conduit 1. Preferably, the built-in permanent magnet 3 is placed 0.5 mm away from the connecting line (the connecting line between the conduit and the multi-arm magnetically controlled soft gripper). Changes in the built-in permanent magnet can change the internal magnetic field, thereby changing the state of the multi-arm magnetically controlled soft gripper under the action of the built-in permanent magnet alone.

[0046] The sixth step is to install external magnets. Small-diameter magnets can be manually controlled, while large-diameter magnets are placed inside the robotic arm as an external magnetic source. This completes the fabrication of the soft gripper robot with coordinated internal and external magnetic source excitation.

[0047] See Figure 6 This verifies the effectiveness of the soft gripper robot with coordinated internal and external magnetic source excitation in this embodiment when grasping a target object inside an S-shaped tube.

[0048] The first step is to place some lightweight small balls 7 inside the narrow and slender S-shaped tube 8.

[0049] The second step involves placing a permanent magnet with a diameter of 4 mm and a length of 4 mm inside the conduit 1, serving as the built-in permanent magnet 3. The magnetic field lines emitted by the built-in permanent magnet 3 are perpendicular to the axis of the conduit. In this single magnetic field, the multi-arm magnetically controlled soft gripper is in a normally closed state.

[0050] The third step is to manually change the position and orientation of the external magnet 4, which has a diameter of 40mm and a thickness of 30mm, thereby changing the magnetic field outside the conduit.

[0051] Fourth, visually determine the position of the lightweight ball 7 to be grasped. When the multi-arm magnetically controlled soft gripper is brought near the lightweight ball 7, move the external magnet 4 until its axis is perpendicular to the guide tube axis (i.e., the gripper axis). When the magnetic lines of force of the built-in permanent magnet 3 and the external magnet 4 are opposite, the multi-arm magnetically controlled soft gripper opens, ready to grasp the lightweight ball 7.

[0052] Fifth, bring the multi-arm magnetically controlled soft gripper 2 close to the lightweight ball 7, keeping it in an open state. While the multi-arm magnetically controlled soft gripper 2 firmly grasps the object, move the external magnet 4 away from the multi-arm magnetically controlled soft gripper 2. This places the multi-arm magnetically controlled soft gripper 2 under the control of the single magnetic source of the built-in permanent magnet 3. Under the control of the built-in permanent magnet 3, the multi-arm magnetically controlled soft gripper 2 tightly holds the lightweight ball. Then, remove the conduit from the S-shaped tube. During the removal process, the multi-arm magnetically controlled soft gripper 2 maintains a firm grip on the lightweight ball, and the removal process is smooth.

[0053] The embodiments of the present invention also provide a method such as Figures 1-6 The control method for the soft gripper robot with coordinated excitation of internal and external magnetic sources in the illustrated embodiment includes operations S1-S3.

[0054] Operate S1 to move the soft gripper robot toward the object to be gripped until the object is within the gripping range of the soft gripper robot.

[0055] Operate S2 to control the external magnet 4 to move towards the multi-arm magnetically controlled soft gripper 2 until the ends of each strip-shaped arm in the multi-arm magnetically controlled soft gripper 2 are open to grasp the object to be grasped. The external magnet applies a magnetic field opposite to that of the built-in permanent magnet. When the external magnet approaches the gripper, the gripper opens and begins to capture the object.

[0056] Operate S3 to remove the external magnet 4, so that the ends of each strip arm are in a closed state. The built-in permanent magnet keeps the gripper in a normally closed state, which facilitates stable gripping of objects under power loss.

[0057] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A soft gripper robot with coordinated internal and external magnetic source excitation, characterized in that, include: The conduit (1), the multi-arm magnetically controlled soft gripper (2) connected to one end of the conduit (1), the built-in permanent magnet (3) located inside the conduit (1), and the external magnet (4) located outside the conduit (1), wherein the multi-arm magnetically controlled soft gripper (2) is located between the built-in permanent magnet (3) and the external magnet (4); The magnetic fields generated by the built-in permanent magnet (3) and the external magnet (4) are in opposite directions; The multi-arm magnetically controlled soft gripper (2) includes multiple strip-shaped arms with arc-shaped end cross sections. Each strip-shaped arm is pre-magnetized radially, and the magnetization direction satisfies the following conditions: under the radial magnetic field generated by the built-in permanent magnet (3) alone, the ends of each strip-shaped arm are in a closed state; under the radial magnetic field generated by the built-in permanent magnet (3) and the external magnet (4) together, the ends of each strip-shaped arm are in an open state, so as to realize the retrieval and transportation of objects in the tube without the need for external magnets to follow, and to realize the wireless and remote drive and object manipulation of the soft gripper robot in complex and narrow environments. The conduit (1) and the multi-arm magnetically controlled soft gripper (2) are both made of silicone; the surface of each of the strip arms is coated with a magnetic mixture of permanent magnet particles and soft material; The soft material is made of platinum-catalyzed silica gel, and the permanent magnet particles are made of neodymium iron boron particles; platinum-catalyzed silica gel serves as the base solution for the neodymium iron boron particles.

2. The soft gripper robot with coordinated internal and external magnetic source excitation as described in claim 1, characterized in that, Also includes: A robotic arm comprising three joints and having seven degrees of freedom; The external magnet (4) is located inside the robotic arm, and the external magnet (4) is moved by the robotic arm.

3. The soft gripper robot with coordinated internal and external magnetic source excitation as described in claim 1, characterized in that, After the A component solution and B component solution of platinum catalytic silica gel are mixed in a 1:1 mass ratio, neodymium iron boron particles are added to form the magnetic mixture.

4. The soft gripper robot with coordinated internal and external magnetic source excitation as described in claim 1, characterized in that, The external magnet (4) is a permanent magnet or an electromagnet.

5. The soft gripper robot with coordinated internal and external magnetic source excitation as described in any one of claims 1-4, characterized in that, The number of strip-shaped arms is 4, and the central angle corresponding to each strip-shaped arm is 45°.

6. The soft gripper robot with coordinated internal and external magnetic source excitation as described in any one of claims 1-4, characterized in that, The outer surface of the conduit (1) is coated with talc.

7. The control method for a soft gripper robot with coordinated internal and external magnetic source excitation as described in any one of claims 1-6, characterized in that, include: Move the soft gripper robot toward the object to be grasped until the object is within the gripping range of the soft gripper robot; Control the external magnet (4) to move toward the multi-arm magnetic control soft gripper (2) until the ends of each strip-shaped arm in the multi-arm magnetic control soft gripper (2) are open to grasp the object to be grasped; Remove the external magnet (4) so ​​that the ends of each of the strip arms are in a closed state.

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