Magnetorheological based bionic flexible gripper device

Abstract

The application relates to the field of magnetorheological and bionic robot grabbing technology, and particularly relates to a bionic flexible gripper device based on magnetorheology, which comprises a main body, a flexible gripper part arranged on the main body and used for grabbing a target object, a driving mechanism arranged on the main body and used for driving the gripper part to complete the grabbing of the target object, and magnetorheological liquid injected into the gripper part. When the gripper part grabs the target object, the contact surface of the gripper part in contact with the target object can adapt to the shape of the target object and wrap the target object through the magnetorheological liquid. The magnetorheological liquid in a low-viscosity Newtonian state is injected into the flexible gripper, so that the contact surface of the flexible gripper can better adapt to the shape of the target object and wrap the target object, the target object can be effectively protected, different sizes and shapes of target objects can be better adapted and grabbed, and therefore the safety, grabbing stability and self-adaptive capacity of the flexible gripper device are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of magnetorheological and bionic robot grasping technology, and particularly relates to a bionic flexible gripper device based on magnetorheology. BACKGROUND

[0002] In marine biology research, scientists need to collect flexible target objects such as corals, sponges, mollusks (such as octopuses and squids), or fish samples. These target objects usually have characteristics such as softness, deformability, smooth surface, or irregular shape, and require flexible, accurate, and reliable grasping and operating tools.

[0003] Traditional robot hands (bionic grippers) usually use metal or other hard materials, and have relatively large structural rigidity. They need to be manually or pre-set adjusted to adapt to different shapes of target objects, often require complex control systems, and have slow response speed. Such rigid structures are prone to causing indentations or damage to the surface of the biological object when grasping target objects with complex shapes, smooth surfaces, and soft textures. They cannot well adapt to the surface shape and characteristics of the target object, lack self-adaptive ability, and limit their application ability in dynamic environments.

[0004] Some flexible robot hand devices use flexible material grippers and negative pressure technology to control the gripper to hold according to the shape of the target object surface. For example, the Chinese patent CN117549341A provides a negative pressure gripper flexible gripper, which uses negative pressure to open the flexible fingers to achieve internal support clamping. The structure includes a connecting part made of elastic material and a drive chamber, and the drive chamber has a deformable area. When the system is connected to a vacuum device, the drive chamber generates negative pressure, and the deformable area deforms first, pulling the metatarsal of the flexible finger inward to deflect and open the flexible finger. However, this scheme requires a reliable negative pressure system, and if there is a lack of negative pressure gas supply system in some environments, the use of the flexible gripper will be limited.

[0005] Some flexible grippers based on the principle of mixed particle blockage have also been applied. For example, the Chinese patent CN113733134A proposes a variable stiffness flexible gripper based on solid-liquid mixture particle blockage. This gripper fills the elastic capsule membrane with a mixture of solid particles and liquid, and when grasping an object, the liquid in the elastic capsule membrane is extracted, causing the solid particles to block and cluster. The elastic membrane capsule changes shape according to the surface shape of the object, and clamps the object through the action of the solid particle blockage cluster. Although this technology based on solid-liquid mixture particle blockage provides variable stiffness function, its defects are also obvious: slow response speed, low adaptability, and violent clamping, which may not perform well in the face of changes and uncertainties. Especially when grasping flexible target objects with complex shapes or irregular surfaces, the particles may not be able to be completely and uniformly distributed and blocked, affecting the grasping stability of the gripper.

[0006] Therefore, how to design a simulation flexible gripper capable of effectively protecting the target object and better adapting and grabbing the target objects of different sizes and shapes is a technical problem to be solved. SUMMARY

[0007] In view of the above problems of the prior art, the technical problem to be solved by the present application is to provide a bionic flexible gripper device based on magneto-rheological, which injects magneto-rheological fluid in a low viscosity Newtonian state in the flexible gripper, so that the contact surface of the flexible gripper can better adapt to the shape of the target object and wrap the target object, effectively protecting the target object, better adapting and grabbing the target objects of different sizes and shapes, thereby improving the safety, grabbing stability and self-adaptive ability of the flexible gripper device.

[0008] In order to solve the above technical problems, the present application adopts the following technical solutions:

[0009] A bionic flexible gripper device based on magneto-rheological, comprising:

[0010] a main body;

[0011] a flexible gripper part arranged on the main body and used for grabbing and releasing the target object;

[0012] a driving mechanism arranged on the main body and used for driving the gripper part to complete the grabbing and releasing of the target object;

[0013] magneto-rheological fluid is injected in the gripper part; when the gripper part grabs the target object, the contact surface of the gripper part in contact with the target object can adapt to the shape of the target object and wrap the target object through the magneto-rheological fluid.

[0014] Preferably, the gripper part comprises two flexible sheet-shaped grippers arranged oppositely; the driving mechanism drives the two sheet-shaped grippers of the gripper part to move towards or away from each other to realize folding or opening, so as to complete the grabbing and releasing of the target object.

[0015] Preferably, each of the two sheet-shaped grippers comprises a flexible inner layer used for contacting the target object and having a contact surface on the side in contact with the target object, and a flexible outer layer arranged on the inner layer and away from the contact surface; the inner layers of the two sheet-shaped grippers are arranged oppositely, and the outer layers are arranged oppositely.

[0016] The inner layer and the outer layer of each of the two sheet-shaped grippers are provided with a hollow liquid cavity, and the liquid cavity of the inner layer is injected with the magneto-rheological fluid;

[0017] When the gripper part grabs the target object, the two sheet-shaped grippers are folded, at this time, non-magneto-rheological fluid is injected into the liquid cavity of the outer layer of the two sheet-shaped grippers, so that the inner layer and the outer layer of the two sheet-shaped grippers produce bending deformation under the action of the magneto-rheological fluid and the non-magneto-rheological fluid to complete the wrapping of the target object;

[0018] When the gripper part releases the grabbed target object, the two sheet-shaped grippers are opened, at this time the non-magnetic rheological liquid injected in the liquid cavity of the outer layer of the two sheet-shaped grippers is discharged, so that the inner layer of the two sheet-shaped grippers is restored to the initial shape under the action of the magnetic rheological liquid.

[0019] Preferably, the inner layer liquid cavity of the two sheet-shaped grippers is provided with an electromagnetic coil;

[0020] When the gripper part grabs the target object and the inner layer and the outer layer of the two sheet-shaped grippers are bent and deformed under the action of the magnetic rheological liquid and the non-magnetic rheological liquid respectively to complete the wrapping of the target object, the current flowing through the electromagnetic coil is adjusted to change the rigidity of the magnetic rheological liquid in the inner layer liquid cavity of the two sheet-shaped grippers, so that the inner layer and the outer layer of the two sheet-shaped grippers can maintain the wrapped state of the target object;

[0021] When the gripper part releases the grabbed target object, the current flowing through the electromagnetic coil is adjusted to restore the rigidity of the magnetic rheological liquid in the inner layer liquid cavity of the two sheet-shaped grippers, so that the inner layer and the outer layer of the two sheet-shaped grippers can be restored to the initial shape.

[0022] Preferably, the gripper part further comprises a fixed plate fixedly arranged on the main body; the two sheet-shaped grippers are respectively rotationally connected to the fixed plate, and the two sheet-shaped grippers can move towards each other or away from each other along the rotationally connected positions on the fixed plate;

[0023] The driving mechanism comprises a driving assembly, a piston rod transmissionally connected with the driving assembly and located below the side of the fixed plate away from the two sheet-shaped grippers, a transmission cross bar arranged on the end of the piston rod away from the driving assembly and parallel to the fixed plate, and two push rods rotationally connected with the transmission cross bar; the first ends of the two push rods are respectively rotationally connected with the transmission cross bar, and the second ends are respectively rotationally connected with the sides of the two sheet-shaped grippers away from each other;

[0024] When the driving assembly drives the piston rod to move towards the fixed plate, the piston rod drives the transmission cross bar to move towards the fixed plate, and the transmission cross bar drives the two push rods to respectively push the two sheet-shaped grippers away from the fixed plate, so that the two sheet-shaped grippers move towards each other along the rotationally connected positions on the fixed plate to realize folding and complete the grabbing of the target object;

[0025] When the driving assembly drives the piston rod to move away from the fixed plate, the piston rod drives the transmission cross bar to move away from the fixed plate, and the transmission cross bar drives the two push rods to respectively pull the two sheet-shaped grippers towards the fixed plate, so that the two sheet-shaped grippers move away from each other along the rotationally connected positions on the fixed plate to realize opening and complete the release of the target object by the gripper part.

[0026] Preferably, the main body has a mounting cavity with a closed bottom and an open top;

[0027] The driving assembly comprises an elastic member arranged at one end of the mounting cavity of the main body, and a movable plate fixedly connected to the elastic member at an end away from the bottom of the liquid cavity of the main body; the piston rod is inserted into the mounting cavity through the opening at the top of the main body and fixedly connected to the movable plate at an end away from the transmission cross bar;

[0028] When the driving assembly controls the compression of the elastic member, the movable plate drives the piston rod to move away from the fixed plate, and the piston rod drives the transmission cross bar to move away from the fixed plate;

[0029] When the driving assembly controls the release of the compressed elastic member, the movable plate drives the piston rod to move towards the fixed plate, and the piston rod drives the transmission cross bar to move towards the fixed plate.

[0030] Preferably, the driving mechanism further comprises a limiting assembly arranged in the mounting cavity of the main body;

[0031] The limiting assembly is used to limit the position of the movable plate when the elastic member is compressed, so that the elastic member remains compressed; and is also used to release the limitation of the position of the movable plate when the elastic member is released, so that the compressed elastic member is released.

[0032] Preferably, the limiting assembly comprises a fixed bottom plate, a motor arranged on the fixed bottom plate, a first rotating rod arranged on the output shaft of the motor and parallel to the fixed bottom plate, two second transmission rods rotatably connected to the two ends of the first transmission rod respectively and arranged parallel to the fixed bottom plate, and two limiting columns arranged on the two sides of the elastic member respectively and parallel to the movement direction of the elastic member and rotatably connected to the second ends of the two second transmission rods respectively; wherein the fixed bottom plate, the motor, the first rotating rod and the second transmission rod are all arranged below the side of the elastic member away from the movable plate;

[0033] The two limiting columns are respectively provided with protrusions extending towards each other at one end away from the second transmission rods;

[0034] The fixed bottom plate is provided with a sliding groove; the two limiting columns are provided with sliding blocks at one end away from the protrusions, and the two limiting columns are in sliding cooperation with the sliding groove on the fixed bottom plate through the sliding blocks;

[0035] When the elastic member is compressed, the output shaft of the motor drives the first rotating rod to rotate in the first direction, the first rotating rod pulls the two second transmission rods towards each other, and the two second transmission rods drive the two limiting columns to move towards each other respectively until the protrusions on the two limiting columns abut against the movable plate, thereby limiting the position of the movable plate and keeping the elastic member compressed;

[0036] When the compressed elastic member needs to be released, the output shaft of the motor drives the first rotating rod to rotate in the second direction, the first rotating rod pushes the two second transmission rods in the direction away from each other, the two second transmission rods drive the two limiting columns to move in the direction away from each other respectively, until the protruding parts on the two limiting columns are separated from the abutment with the movable plate, the position limiting of the movable plate is released, and the elastic member is released.

[0037] Preferably, a limiting plate is fixedly arranged above the protruding parts of the two limiting columns in the mounting cavity of the main body, and the limiting plate can limit the position of the movable plate when the elastic member is released.

[0038] Preferably, the end of the piston rod away from the transmission cross rod passes through the opening and the limiting plate of the main body in sequence to realize the fixed connection with the movable plate, and the piston rod is in sealing sliding fit with the opening and the limiting plate of the main body.

[0039] When the elastic member is compressed, a piston in sealing sliding fit with the inner side wall of the mounting cavity of the main body is arranged on the piston rod and located between the opening and the limiting plate of the main body; a space between the piston and the opening of the main body forms a closed oil chamber; and the main body is provided with an inlet and outlet port in communication with the oil chamber.

[0040] The driving mechanism further comprises a hydraulic oil control mechanism.

[0041] When the elastic member needs to be compressed, the hydraulic oil control mechanism pumps high-pressure oil into the oil chamber through the inlet and outlet port, and pushes the piston, the piston rod and the movable plate in the direction of the elastic member through the high-pressure oil, so as to realize the compression of the elastic member.

[0042] When the elastic member needs to be released, the hydraulic oil control mechanism pumps out the high-pressure oil in the oil chamber through the inlet and outlet port, and the limiting assembly releases the position limiting of the movable plate, so that the compressed elastic member is released.

[0043] Compared with the prior art, the bionic flexible gripper device based on magneto-rheological in the application has the following beneficial effects:

[0044] When the target object (such as a flexible organism) is grasped, the driving mechanism on the main body drives the gripper part to grasp the target object, and the gripper part is injected with magneto-rheological fluid. When the gripper part grasps the target object, the contact surface of the gripper part in contact with the target object can adapt to the shape of the target object and wrap the target object through the magneto-rheological fluid. By injecting the magneto-rheological fluid in a low-viscosity Newtonian state into the gripper part, the contact surface of the gripper part can better adapt to the shape of the target object and wrap the target object. Not only can the target object be effectively protected, but also different sizes and shapes of target objects can be better adapted and grasped, thereby improving the safety, grasping stability and self-adaptive ability of the flexible gripper device. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to make the objects, technical solutions and advantages of the present application clearer, the following will further describe the present application in conjunction with the accompanying drawings, in which:

[0046] Figure 1 Structure diagram of the bionic flexible gripper device based on magneto-rheological.

[0047] Figure 2 Structure diagram of two sheet-shaped grippers.

[0048] Figure 3 Front view of the sheet-shaped gripper.

[0049] Figure 4 Sectional view of the internal independent layer of the sheet-shaped gripper.

[0050] Figure 5 Structure diagram of the driving mechanism.

[0051] Figure 6 Structure diagram of the limiting assembly.

[0052] The reference signs in the drawings of the specification include: main body 1, mounting cavity 101, sheet-shaped gripper 2, inner layer 201, outer layer 202, liquid cavity 203, electromagnetic coil 204, contact surface 205, magneto-rheological liquid 206, main cavity 207, auxiliary cavity 208, liquid inlet 209, fixed plate 3, piston rod 4, transmission cross rod 5, push rod 6, elastic member 7, movable plate 8, fixed bottom plate 9, motor 10, first rotating rod 11, second transmission rod 12, limiting column 13, protruding part 14, sliding groove 15, sliding block 16, limiting plate 17, piston 18, oil cavity 19, liquid inlet / outlet 20. DETAILED DESCRIPTION

[0053] In order to make the objects, technical solutions and advantages of the present application clearer, the following will further describe the present application in conjunction with the accompanying drawings, in which:

[0054] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not mean that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0055] The following detailed explanation illustrates the specific implementation methods:

[0056] Example:

[0057] This embodiment discloses a biomimetic (Venus flytrap-inspired) flexible gripper device based on magnetorheology.

[0058] like Figure 1 As shown, the biomimetic flexible gripper device based on magnetorheology includes:

[0059] Main body 1; The main body has a mounting cavity 101 that is closed at the bottom and open at the top;

[0060] A flexible gripper section is provided on the main body for gripping and releasing the target object;

[0061] The drive mechanism, located on the main body, is used to drive the gripper to grasp and release the target object;

[0062] The gripper is filled with magnetorheological fluid; when the gripper grasps the target object, the magnetorheological fluid causes the contact surface 205 between the gripper and the target object to adapt to the shape of the target object and wrap around the target object.

[0063] This invention, when grasping a target object (such as a flexible organism), uses a drive mechanism on the main body to drive the gripper portion to grasp the target object. The gripper portion is injected with magnetorheological fluid. When the gripper portion grasps the target object, the magnetorheological fluid causes the contact surface of the gripper portion to adapt to the shape of the target object and envelop it. By injecting a low-viscosity, Newtonian-like magnetorheological fluid into the gripper portion, this invention allows the contact surface of the gripper portion to better adapt to the shape of the target object and envelop it. This not only effectively protects the target object but also better adapts to and grasps targets of different sizes and shapes, thereby improving the safety, grasping stability, and self-adaptability of the flexible gripper device.

[0064] To better illustrate the technical solution of the present invention, this embodiment is described in the following parts.

[0065] I. Gripper section

[0066] like Figure 2 As shown, the gripper part includes two flexible (can be made of flexible rubber material) sheet-like grippers 2 (left sheet-like gripper and right sheet-like gripper) arranged opposite each other; the drive mechanism drives the two sheet-like grippers of the gripper part to move closer or further away from each other to achieve closing or opening, so as to complete the gripping and release of the target object.

[0067] The gripper part also includes a fixing plate 4 fixedly mounted on the main body; two plate-shaped grippers (the lowest end of the intermediate shaft is the fixed end) are respectively rotatably connected (in this embodiment, the rotatable connection is a hinge) to the fixing plate 4, and the two plate-shaped grippers can move closer to each other or further away from each other along the rotatable connection position on the fixing plate 4.

[0068] The two plate-like claws are shaped like Venus flytrap leaves, including a palm and fingers that are interconnected. The fingers of the two plate-like claws are staggered, allowing them to interlock during the wrapping stage, thus enveloping the target object within the claws.

[0069] Both sheet-like grippers include a flexible inner layer 201 for contacting the target object, with the side surface in contact with the target object being the contact surface 205, and a flexible outer layer 202 disposed on the inner layer facing away from the contact surface; the inner layers 201 of the two sheet-like grippers are arranged opposite each other, and the outer layers 202 are arranged opposite each other; the inner layers 201 and the outer layers 202 are composite together.

[0070] Both the inner layer 201 and the outer layer 202 of the two plate-shaped grippers are provided with hollow liquid cavities 203, and the liquid cavity 203 of the inner layer is filled with magnetorheological fluid.

[0071] When the jaw part grabs the target object, the two sheet-shaped jaws are closed, at this time (through the magneto-rheological control mechanism) the non-magneto-rheological liquid is injected into the liquid cavity of the outer layer of the two sheet-shaped jaws, so that the inner layer and the outer layer of the two sheet-shaped jaws are bent and deformed (i.e. adapt to the shape of the target object) under the action of the magneto-rheological liquid and the non-magneto-rheological liquid to complete the wrapping of the target object; wherein the non-magneto-rheological liquid is silicone oil.

[0072] When the jaw part releases the grabbed target object, the two sheet-shaped jaws are opened, at this time (through the magneto-rheological control mechanism) the non-magneto-rheological liquid injected into the liquid cavity of the outer layer of the two sheet-shaped jaws is discharged, so that the inner layer of the two sheet-shaped jaws is restored to the initial shape (i.e. sheet-shaped) under the action of the magneto-rheological liquid.

[0073] It should be noted that although the two sheet-shaped jaws are flexible (i.e. low stiffness, deformable), they still have a certain stiffness and resilience. When the liquid cavity of the outer layer of the sheet-shaped jaws is injected with silicone oil, the sheet-shaped jaws cannot maintain their initial shape (sheet-shaped) under the action of the silicone oil, at this time the sheet-shaped jaws can be deformed to adapt to the shape of the target object; when the silicone oil injected into the liquid cavity of the outer layer of the sheet-shaped jaws is discharged, since the magneto-rheological liquid is a low-viscosity Newtonian fluid state, it cannot fix the shape of the sheet-shaped jaws, at this time the sheet-shaped jaws rebound to return to the initial shape (sheet-shaped).

[0074] As shown in Figure 3 , the liquid cavities of the inner layer and the outer layer of the two sheet-shaped jaws each contain a main chamber 207, a secondary chamber 208 and a liquid inlet 209; the size of the main chamber 207 is larger than that of the secondary chamber 208, the secondary chamber 208 is relatively thinner, and presents a structure feature of gradually narrowing towards the two ends and the finger part, so that a gradient effect is formed during liquid filling, realizing graded deformation and step-by-step response, and ensuring smooth and smooth grabbing process.

[0075] The thickness of the shell of the outer layer of the two sheet-shaped jaws decreases from the center to both sides, so that the jaws can not only bear a certain load, but also more flexibly adapt to target objects of different shapes, so that the structure reaches a balance between rigidity and flexibility. The shell of the outer layer of the two sheet-shaped jaws is provided with a pair of grooves along the central symmetry plane of the jaw, which provides deformation space when the jaw is pressed inward.

[0076] As shown in Figure 4 , an independent interlayer is provided in the inner layer liquid cavity of the two sheet-shaped jaws, and an electromagnetic coil 204 is installed in the interlayer for generating a magnetic field to control the rheological properties of the magneto-rheological liquid 206. The magnetic field strength of the electromagnetic coil 204 has a linear relationship with the current size, and the magnetic field direction is parallel to the jaw axis, so that the magneto-rheological liquid 206 forms a chain or columnar structure in this direction.

[0077] When the jaw part grabs the target object and the inner layer and the outer layer of the two sheet-shaped jaws are bent and deformed under the action of the magnetorheological fluid and the non-magnetorheological fluid to complete the wrapping of the target object, the current flowing through the electromagnetic coil is adjusted to change (increase) the rigidity of the magnetorheological fluid in the inner layer liquid cavity of the two sheet-shaped jaws, so that the inner layer and the outer layer of the two sheet-shaped jaws can maintain the wrapped state of the target object and adapt to the shape of the target object.

[0078] When the jaw part releases the grabbed target object, the current flowing through the electromagnetic coil is adjusted (by the magnetorheological control mechanism) to restore the rigidity of the magnetorheological fluid in the inner layer liquid cavity of the two sheet-shaped jaws, so that the inner layer and the outer layer of the two sheet-shaped jaws can be restored to the initial shape.

[0079] During the entire grabbing process, the rigidity adjustment of the magnetorheological fluid plays a key role in the stability of clamping. After the target object is wrapped by the sheet-shaped jaws, the magnetic field generated by the electromagnetic coil acts on the magnetorheological fluid, which rapidly changes from the initial low-viscosity Newtonian fluid state to high-viscosity or quasi-solid state, thereby enhancing the overall rigidity of the sheet-shaped jaws and improving the support force and shape adaptability to the target object, thereby improving the grabbing stability of the flexible jaw device. And by controlling the current size, the rigidity of the magnetorheological fluid can be dynamically adjusted, so that the jaws can smoothly switch between flexibility and rigidity, ensuring stable grabbing of target objects of different shapes, while effectively reducing the risk of sliding or deformation caused by different surface characteristics of the target object.

[0080] The electromagnetic coil has a length L and a number of turns N, and the magnetic field strength generated by the electromagnetic coil is:

[0081]

[0082] The magnetorheological fluid includes an elastic matrix and high-permeability low-hysteresis carbonyl iron powder particles in a columnar or chain structure distributed in the elastic matrix, ensuring that the magnetorheological fluid can quickly respond and adjust the rigidity under the action of the magnetic field. The three critical magnetic fields at which the magnetorheological fluid undergoes phase transition are HC1, HC2, and HC3:

[0083] When B<HC1, the magnetorheological fluid is completely in a fluid state, and the ferromagnetic particles are randomly distributed;

[0084] When HC1<B<HC2, a chain structure begins to form, and the chain and the particle coexist and are randomly distributed; when HC2<B<HC3, a columnar structure begins to form, and the column and the chain coexist;

[0085] When H>HC3, the particles all form a columnar structure. This process consumes less energy, is reversible, and occurs quickly.

[0086] II. Drive mechanism

[0087] For example, Figure 5As shown, the driving mechanism comprises a driving assembly, a piston rod 4 in transmission connection with the driving assembly and located below the fixed plate away from the two sheet-shaped clamping jaws, a transmission crossbar 5 arranged on the piston rod 4 away from the driving assembly and parallel to the fixed plate, and two push rods 6 in rotational connection with the transmission crossbar 5; the first ends of the two push rods 6 are respectively in rotational connection with the transmission crossbar 5, and the second ends are respectively in rotational connection with the sides away from the two sheet-shaped clamping jaws 2; wherein the outer layer 202 of the sheet-shaped clamping jaw 2 is provided with a back plate, and the second end of the push rod is in rotational connection with the back plate on the outer layer 202 of the sheet-shaped clamping jaw 2.

[0088] When the driving assembly drives the piston rod to move towards the fixed plate, the piston rod drives the transmission crossbar to move towards the fixed plate, and the transmission crossbar drives the two push rods to push the two sheet-shaped clamping jaws away from the fixed plate, so that the two sheet-shaped clamping jaws move towards each other along the rotational connection position on the fixed plate to realize folding and complete the grabbing of the target object.

[0089] When the driving assembly drives the piston rod to move away from the fixed plate, the piston rod drives the transmission crossbar to move away from the fixed plate, and the transmission crossbar drives the two push rods to pull the two sheet-shaped clamping jaws towards the fixed plate, so that the two sheet-shaped clamping jaws move away from each other along the rotational connection position on the fixed plate to realize unfolding and complete the release of the target object by the clamping jaw part. The included angle between the piston rod and the push rod is less than 90°, and the included angle of the push rod itself is greater than 90°, so as to ensure that the push rod can efficiently transmit power during movement.

[0090] It should be noted that the fixed plate 3 is fixed on the main body 1 and remains stationary during the movement of the piston rod 4, the transmission crossbar 5 and the push rod 6.

[0091] The driving mechanism designed in the application can effectively drive the two sheet-shaped clamping jaws of the clamping jaw part to move towards each other or away from each other to realize folding or unfolding, and complete the grabbing and release of the target object. Moreover, the driving mechanism has a simple and stable structure, which is conducive to driving the clamping jaw part to act in various scenes, thereby assisting to improve the safety and grabbing stability of the flexible clamping jaw device.

[0092] Three, driving assembly

[0093] The main body 1 has a mounting cavity 101 which is closed at the bottom and open at the top;

[0094] The driving assembly comprises a resilient member 7 arranged at one end of the bottom of the mounting cavity of the main body, and a movable plate 8 fixedly connected to the end of the resilient member 7 away from the bottom of the liquid cavity of the main body; the end of the piston rod 4 away from the transmission crossbar 5 is inserted into the mounting cavity 101 of the main body 1 and fixedly connected to the movable plate 8; the resilient member is a rigid spring.

[0095] When the driving assembly controls the compression of the elastic member, the movable plate drives the piston rod to move away from the fixed plate, the piston rod drives the transmission cross rod to move away from the fixed plate, the transmission cross rod drives the two push rods to respectively push the two sheet-shaped clamping jaws away from the fixed plate, so that the two sheet-shaped clamping jaws move away from each other along the rotating connection position on the fixed plate to realize opening, and the release of the target object by the clamping jaw part is completed.

[0096] When the driving assembly controls the release of the compressed elastic member, the movable plate drives the piston rod to move close to the fixed plate, the piston rod drives the transmission cross rod to move close to the fixed plate, and the transmission cross rod drives the two push rods to respectively push the two sheet-shaped clamping jaws away from the fixed plate, so that the two sheet-shaped clamping jaws move close to each other along the rotating connection position on the fixed plate to realize closing, and the grasping of the target object is completed.

[0097] In the present application, the two sheet-shaped clamping jaws of the clamping jaw part are driven to move close to each other or away from each other by the driving force released by the elastic member to realize closing or opening, which has the advantages of stable structure and low cost.

[0098] Four, limiting assembly

[0099] The driving mechanism further comprises a limiting assembly arranged in the mounting cavity of the main body;

[0100] The limiting assembly is used to limit the position of the movable plate when the elastic member is compressed, so that the elastic member remains compressed; and is also used to release the limitation of the position of the movable plate when the elastic member is released, so that the compressed elastic member is released.

[0101] As shown in Figure 6 The limiting assembly comprises a fixed bottom plate 9, a motor 10 arranged on the fixed bottom plate 9, a first rotating rod 11 arranged in the middle position of the motor and capable of rotating with the output shaft of the motor and arranged parallel to the fixed bottom plate, two second transmission rods 12 respectively rotatably connected to the two ends of the first transmission rod 11 and arranged parallel to the fixed bottom plate, and two limiting columns 13 arranged opposite to the two sides of the elastic member 7 and arranged along the movement direction of the elastic member and respectively rotatably connected to the second ends of the two second transmission rods 12; the fixed bottom plate 9, the motor 10, the first rotating rod 11 and the second transmission rod 12 are all arranged below the side of the elastic member 7 away from the movable plate 8; the motor is a common rotating motor.

[0102] The ends of the two limiting columns 13 away from the second transmission rod are respectively provided with protruding portions 14 extending towards each other;

[0103] The fixed bottom plate is provided with a sliding groove 15; the ends of the two limiting columns away from the protruding portions are provided with sliding blocks 16, and the two limiting columns are in sliding cooperation with the sliding groove 15 on the fixed bottom plate through the sliding blocks 16;

[0104] When the elastic member is compressed, the output shaft of the motor drives the first rotating rod to rotate in the first direction (forward rotation), the first rotating rod pulls the two second transmission rods towards each other, the two second transmission rods respectively drive the two limiting columns to move towards each other, until the protrusions on the two limiting columns abut against the movable plate (the height of the protrusions on the limiting columns should be higher than the height of the movable plate after the elastic member is compressed), the position of the movable plate is limited, and the elastic member is kept compressed;

[0105] When the compressed elastic member needs to be released, the output shaft of the motor drives the first rotating rod to rotate in the second direction (reverse rotation), the first rotating rod pushes the two second transmission rods away from each other, the two second transmission rods respectively drive the two limiting columns to move away from each other, until the protrusions on the two limiting columns are disengaged from the movable plate, the position of the movable plate is released, and the elastic member is released.

[0106] The limiting plate 17 is fixedly arranged in the installation cavity 101 of the main body 1 above the protrusions 14 of the two limiting columns 13, and can limit the position of the movable plate 8 when the elastic member 7 is released.

[0107] The present application adjusts the compression and release state of the elastic member through the limiting assembly, so that the elastic member can effectively release the driving force to drive the two sheet-shaped clamping jaws of the clamping jaw part to move towards or away from each other to realize folding or opening, thereby assisting to realize the grasping function of the flexible clamping jaw device. And the structure of the limiting assembly is simple and stable, which is conducive to adjusting the state of the elastic member in various scenes, thereby assisting to improve the safety and grasping stability of the flexible clamping jaw device.

[0108] Five, hydraulic oil control mechanism

[0109] The end of the piston rod 4 away from the transmission cross rod 5 passes through the opening of the main body 1 and the limiting plate 17 in sequence to realize the fixed connection with the movable plate 8, and the piston rod 4 and the opening of the main body and the limiting plate 17 are in sealing sliding fit;

[0110] When the elastic member 7 is compressed, the piston 18 in sealing sliding fit with the inner side wall of the installation cavity 101 of the main body 1 is sleeved on the piston rod 4 at the position between the opening of the main body 1 and the limiting plate 17; the space between the piston 18 and the opening of the main body 1 forms a closed oil cavity 19; the main body is provided with an inlet and outlet port 20 communicating with the oil cavity; the inlet and outlet port 20 is provided with a two-way controllable electromagnetic valve supporting the switching of liquid flow direction.

[0111] The driving mechanism further comprises a hydraulic oil control mechanism;

[0112] When the elastic member needs to be compressed, the hydraulic oil control mechanism pumps high-pressure oil into the oil cavity through the inlet and outlet ports (expands the volume of the oil cavity), and pushes the piston, piston rod and movable plate towards the elastic member through the high-pressure oil, so as to realize the compression of the elastic member.

[0113] When the elastic member needs to be released, the hydraulic oil control mechanism pumps the high-pressure oil in the oil cavity out through the inlet and outlet ports, and the limiting assembly releases the limiting of the position of the movable plate, so that the compressed elastic member is released.

[0114] The present application adjusts the compression and release state of the elastic member by the way of controlling the high-pressure oil through the hydraulic oil control mechanism, so that the elastic member can effectively release the driving force to drive the two sheet-shaped clamps of the clamp part to move towards or away from each other to realize folding or opening, thereby assisting to realize the grasping function of the flexible clamp device.

[0115] Six, workflow

[0116] In this embodiment, the working process of the biomimetic flexible clamp device based on magneto-rheological is as follows:

[0117] 1, initial state

[0118] In the initial state, the elastic member is in a compressed state, the movable plate is clamped by the protruding part of the limiting column to form a limit, and the liquid cavity of the sheet-shaped clamp and the oil cavity of the main body are in a hollow state.

[0119] The liquid cavity in the inner layer of the two sheet-shaped clamps is filled with magneto-rheological fluid, the magneto-rheological fluid is in a low viscosity Newtonian fluid state, and the sheet-shaped clamp maintains the initial shape (sheet shape).

[0120] 2, grasping state

[0121] When the flexible clamp device approaches the target object, the microcomputer issues a command to control the motor to reverse (or rotate), the output shaft of the motor drives the first rotating rod to reverse, the first rotating rod pushes the two second transmission rods away from each other, the two second transmission rods respectively drive the two limiting columns to move away from each other, until the protruding parts on the two limiting columns are separated from the abutment with the movable plate, the limiting of the position of the movable plate is released, and the elastic member is released.

[0122] The movable plate drives the piston rod to move towards the fixed plate, the piston rod drives the transmission cross bar to move towards the fixed plate, and the transmission cross bar drives the two push rods to push the two sheet-shaped clamps away from the fixed plate, so that the two sheet-shaped clamps move towards each other along the rotating connection position on the fixed plate to realize folding.

[0123] The magnetic rheological control mechanism injects non-magnetic rheological liquid (silicon liquid) into the liquid cavity of the outer layer of the two sheet-shaped clamping jaws, so that the inner layer and the outer layer of the two sheet-shaped clamping jaws are bent and deformed under the action of the magnetic rheological liquid and the non-magnetic rheological liquid to complete the wrapping of the target object; the current flowing through the electromagnetic coil is adjusted to change the rigidity of the magnetic rheological liquid in the liquid cavity of the inner layer of the two sheet-shaped clamping jaws, so that the inner layer and the outer layer of the two sheet-shaped clamping jaws can maintain the wrapped state of the target object and adapt to the shape of the target object to complete the wrapping and grabbing of the target object.

[0124] 3, released state

[0125] When the target object needs to be released, the magnetic rheological control mechanism adjusts the current flowing through the electromagnetic coil to adjust the rigidity of the magnetic rheological liquid in the liquid cavity of the inner layer of the sheet-shaped clamping jaw, and the magnetic rheological liquid returns to the low-viscosity Newtonian fluid state, while the non-magnetic rheological liquid (silicon liquid) injected into the liquid cavity of the outer layer of the clamping jaw part is discharged, so that the inner layer and the outer layer of the two sheet-shaped clamping jaws can be restored to the initial state.

[0126] The hydraulic oil control mechanism pumps high-pressure oil into the oil cavity through the inlet and outlet, and pushes the piston, piston rod and movable plate towards the direction of the elastic element through the high-pressure oil. The elastic element is compressed, driving the piston rod to move away from the fixed plate. The piston rod drives the transmission cross bar to move away from the fixed plate, and the transmission cross bar drives the two push rods to pull the two sheet-shaped clamping jaws towards the fixed plate, so that the two sheet-shaped clamping jaws move away from each other along the rotating connection position on the fixed plate to realize opening, and complete the release of the target object by the clamping jaw part.

[0127] When the elastic element is compressed to the position, the microcomputer sends a command, and the output shaft of the motor drives the first rotating rod to rotate forward (or reverse), the first rotating rod pulls the two second transmission rods towards each other, and the two second transmission rods drive the two limiting columns to move towards each other until the protruding parts on the two limiting columns abut against the movable plate, limiting the position of the movable plate, so that the elastic element remains compressed and returns to the initial state.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit the technical solutions. Those skilled in the art should understand that those who modify or equivalently replace the technical solutions of the present application without departing from the purpose and scope of the technical solutions should be covered in the scope of the claims of the present application.

Claims

1. A magneto-rheological based bionic flexible gripper device, characterized in that, The utility model relates to a kind of gripper, including: Main body; Flexible gripper part is arranged on main body, for grabbing target object; Driving mechanism is arranged on main body, for driving gripper part to complete the grabbing of target object; Magnetorheological fluid is injected in gripper part;When gripper part grabs target object, the contact surface of gripper part contacted with target object can be adapted to the shape of target object and is wrapped to target object by magnetorheological fluid; Gripper part includes two flexible sheet-shaped grippers arranged oppositely;Driving mechanism realizes folding or opening by driving two sheet-shaped grippers of gripper part to move mutually close or mutually far apart, to complete the grabbing and release of target object; Two sheet-shaped grippers each include flexible inner layer for contacting target object, and the side surface contacted with target object is the contact surface, and flexible outer layer is arranged on the side of inner layer away from contact surface;Inner layer of two sheet-shaped grippers is arranged oppositely, and outer layer is arranged oppositely; The hollow liquid cavity is arranged in the inner layer and the outer layer of two sheet-shaped grippers, and magnetorheological fluid is injected in the liquid cavity of inner layer; When gripper part grabs target object, two sheet-shaped grippers fold, and non-magnetorheological fluid is injected into the liquid cavity of outer layer of two sheet-shaped grippers at this time, so that inner layer and outer layer of two sheet-shaped grippers are bent and deformed under the action of magnetorheological fluid and non-magnetorheological fluid to complete the wrapping of target object; When gripper part releases grabbed target object, non-magnetorheological fluid injected into the liquid cavity of outer layer of two sheet-shaped grippers is discharged at this time, so that inner layer of two sheet-shaped grippers is restored to initial state under the action of magnetorheological fluid; Two sheet-shaped grippers each include palm part and finger part, palm part and finger part are mutually penetrated, and fingers of two sheet-shaped grippers are staggered; The thickness of shell of outer layer of two sheet-shaped grippers decreases from center to both sides.

2. The magneto-rheologically based bionic flexible gripper device of claim 1, wherein: Electromagnetic coil is arranged in the liquid cavity of inner layer of two sheet-shaped grippers; When gripper part grabs target object and inner layer and outer layer of two sheet-shaped grippers are bent and deformed under the action of magnetorheological fluid and non-magnetorheological fluid to complete the wrapping of target object, the rigidity of magnetorheological fluid in the liquid cavity of inner layer of two sheet-shaped grippers is changed by adjusting current flowing through electromagnetic coil, so that inner layer and outer layer of two sheet-shaped grippers can maintain the state of wrapping target object; When gripper part releases grabbed target object, the rigidity of magnetorheological fluid in the liquid cavity of inner layer of two sheet-shaped grippers is restored by adjusting current flowing through electromagnetic coil, so that inner layer and outer layer of two sheet-shaped grippers can be restored to initial state.

3. The magneto-rheologically based bionic flexible gripper device of claim 1, wherein: Gripper part also includes fixed plate fixedly arranged on main body;Two sheet-shaped grippers are respectively rotatably connected to fixed plate, and two sheet-shaped grippers can move mutually close or mutually far apart along the rotatable connection position on fixed plate; Driving mechanism includes driving assembly, piston rod in transmission connection with driving assembly and located below the side of fixed plate away from two sheet-shaped grippers, transmission cross bar arranged on the end of piston rod away from driving assembly and arranged in parallel with fixed plate, and two push rods in transmission connection with transmission cross bar;First end of two push rods is respectively in transmission connection with transmission cross bar, and second end is respectively in transmission connection with the side away from two sheet-shaped grippers; When the driving assembly drives the piston rod to move towards the fixed plate, the piston rod drives the transmission cross rod to move towards the fixed plate, the transmission cross rod drives the two push rods to push the two sheet-shaped clamping jaws away from the fixed plate, so that the two sheet-shaped clamping jaws move away from each other along the rotating connection position on the fixed plate to realize opening, and the clamping jaw part releases the target object. When the driving assembly drives the piston rod to move away from the fixed plate, the piston rod drives the transmission cross rod to move away from the fixed plate, the transmission cross rod drives the two push rods to pull the two sheet-shaped clamping jaws towards the fixed plate, so that the two sheet-shaped clamping jaws move towards each other along the rotating connection position on the fixed plate to realize closing, and the clamping jaw part captures the target object.

4. The magneto-rheologically based bionic flexible gripper device of claim 3, wherein: The main body has a bottom-closed and top-open installation cavity; The driving assembly includes an elastic member arranged at one end of the bottom of the installation cavity of the main body, and a movable plate fixedly connected to the end of the elastic member away from the bottom of the installation cavity of the main body; the end of the piston rod away from the transmission cross rod is inserted into the installation cavity through the opening at the top of the main body and is fixedly connected to the movable plate; When the driving assembly controls the compression of the elastic member, the movable plate drives the piston rod to move away from the fixed plate, and the piston rod drives the transmission cross rod to move away from the fixed plate; When the driving assembly controls the release of the compressed elastic member, the movable plate drives the piston rod to move towards the fixed plate, and the piston rod drives the transmission cross rod to move towards the fixed plate.

5. The magneto-rheologically based bionic flexible gripper device of claim 4, wherein: The driving mechanism further includes a limiting assembly arranged in the installation cavity of the main body; The limiting assembly is used to limit the position of the movable plate when the elastic member is compressed, so that the elastic member remains compressed; and is also used to release the limitation of the position of the movable plate when the elastic member is released, so that the compressed elastic member is released.

6. The magneto-rheologically based bionic flexible gripper device of claim 5, wherein: The limiting assembly includes a fixed bottom plate, a motor arranged on the fixed bottom plate, a first rotating rod arranged on the output shaft of the motor and parallel to the fixed bottom plate, two second transmission rods rotatably connected to the two ends of the first rotating rod and parallel to the fixed bottom plate, and two limiting columns arranged on the two sides of the elastic member and parallel to the movement direction of the elastic member and rotatably connected to the second ends of the two second transmission rods; wherein the fixed bottom plate, the motor, the first rotating rod and the second transmission rod are all arranged below the side of the elastic member away from the movable plate; The ends of the two limiting columns away from the second transmission rods are respectively provided with protrusions extending towards each other; The fixed bottom plate is provided with a sliding groove; the ends of the two limiting columns away from the protrusions are provided with sliding blocks, and the two limiting columns are slidably connected to the sliding groove on the fixed bottom plate through the sliding blocks; When the elastic member is compressed, the output shaft of the motor drives the first rotating rod to rotate in the first direction, the first rotating rod pulls the two second transmission rods towards each other, the two second transmission rods drive the two limiting columns to move towards each other, until the protrusions on the two limiting columns abut against the movable plate, the position of the movable plate is limited, and the elastic member remains compressed; When the compressed elastic member is released, the movable plate drives the piston rod to move towards the fixed plate, and the piston rod drives the transmission cross rod to move towards the fixed plate. When the compressed elastic member needs to be released, the output shaft of the motor drives the first rotating rod to rotate in the second direction, the first rotating rod pushes the two second transmission rods away from each other, the two second transmission rods drive the two limiting columns to move away from each other, until the protruding portions on the two limiting columns are separated from the abutment with the movable plate, the position of the movable plate is limited, and the elastic member is released.

7. The magneto-rheologically based bionic flexible gripper device of claim 6, wherein: The mounting cavity of the main body is fixedly provided with a limiting plate above the protruding portions of the two limiting columns, and the limiting plate can limit the position of the movable plate when the elastic member is released.

8. The magneto-rheologically based bionic flexible gripper device of claim 7, wherein: The end of the piston rod away from the transmission cross rod is fixedly connected with the movable plate by sequentially penetrating the opening and the limiting plate of the main body, and the piston rod is in sealing sliding fit with the opening and the limiting plate of the main body. When the elastic member is compressed, a piston in sealing sliding fit with the inner side wall of the mounting cavity of the main body is arranged on the piston rod between the opening and the limiting plate of the main body; a space between the piston and the opening of the main body forms a closed oil chamber; and the main body is provided with an inlet and outlet port in communication with the oil chamber. The driving mechanism further comprises a hydraulic oil control mechanism. When the elastic member needs to be compressed, the hydraulic oil control mechanism pumps high-pressure oil into the oil chamber through the inlet and outlet port, and pushes the piston, the piston rod and the movable plate towards the elastic member through the high-pressure oil, so as to compress the elastic member. When the elastic member needs to be released, the hydraulic oil control mechanism pumps out the high-pressure oil in the oil chamber through the inlet and outlet port, and the limiting assembly releases the limitation on the position of the movable plate, so that the compressed elastic member is released.

Images