A super-elastic film gripper and method of gripping

Abstract

The application relates to a super-elasticity film grabber and a grabbing method, which comprise a super-elasticity film, a fixing component, a sealing plug, a gas guide pipe and a gas conveying pump; the fixing component is installed on a mechanical arm or a translation table; the gas guide pipe is a hollow circular pipe, and two ends of the pipe are respectively sealedly connected with the super-elasticity film and the gas conveying pump; the super-elasticity film is a spherical latex material film with an air inlet and outlet hole, and is sealedly connected with the fixing component and the gas guide pipe through the sealing plug; when the gas conveying pump conveys gas, the tension of the super-elasticity film and the gas pressure difference jointly act on the super-elasticity film to make the super-elasticity film expand and contract, so that the enveloping grabbing function of the super-elasticity film is realized. The super-elasticity film is used as an actuator to contact a target object and realize the grabbing function, and the application has the advantages of simple structure, easy manufacturing, convenient replacement and maintenance of parts and the like; based on the use method of the flexible grabber, the application can better adapt to the shape of the target object, realize the enveloping grabbing of target objects with different shapes, and does not need to continuously supply energy.

Description

TECHNICAL FIELD

[0001] The present application relates to a flexible gripper, more particularly to a super-elastic film gripper and a gripping method. BACKGROUND

[0002] In 1977, Japanese scholar Hirose Mitsuo designed a rope-driven flexible hinge gripper. Due to the fact that flexible mechanisms can adapt to the shape of the object being gripped, and are simple to operate and reliable in performance, they have broad application prospects. In recent years, with the development of flexible materials, a series of flexible gripper products have appeared. In the industrial field, flexible grippers can perform production, handling and other operations without damaging the product; in the civil field, flexible grippers can grip water cups, food and the like according to human hand bionics. Based on the essential characteristics of safety and flexibility of flexible grippers, scholars from various countries have begun to design and research in this regard.

[0003] In the research of modern flexible grippers, according to the gripping mode of the flexible gripper, it is mainly divided into four categories: winding gripping, multi-finger gripping, enveloping gripping and adsorbing gripping. The design inspiration of winding gripping comes from soft gripping structures such as snakes, elephant trunks and octopus claws in nature, which wind around the target object to achieve gripping, fixing and operation of the target; the gripper of multi-finger gripping is usually designed as 2-5 "fingers", which bends the "fingers" to achieve spatial locking gripping of the target object; enveloping gripping is to form a whole or partial envelope of the target object, and then capture the target object; adsorbing gripping usually uses the contact and adhesion between the gripper and the target surface to complete the gripping of the target, which is more suitable for gripping objects with smooth surfaces or smooth shapes.

[0004] Most of the existing flexible grippers adopt winding gripping and multi-finger gripping. The gripper and the target object of these two gripping modes are usually point contact or small-area surface contact. This smaller contact area can easily cause stress concentration when gripping some special objects such as soft and fragile objects, thereby causing damage to the target object. The gripper using adsorbing gripping usually has the problems of small output force or great requirements for the shape of the target object. The gripper using enveloping gripping has a larger contact area between the gripper and the target object. This kind of gripper is usually a particle gripper driven by negative pressure, and the contact part between the gripper and the target object is a spherical film filled with particle materials. However, in order to envelop the target object as much as possible, the gripper needs to continuously press on the surface of the object, and the applied force will greatly increase, which can easily cause damage to the target object. SUMMARY

[0005] In order to overcome the shortcomings of poor shape adaptability and the need for continuous energy supply of the existing flexible gripper, the application aims to provide a super-elastic film gripper and a gripping method. The gripper can realize basic protective and flexible gripping, better adapt to the surface shape of the target object by using the elastic deformation of the super-elastic film during the gripping process, and grasp the object without subsequent energy supply.

[0006] In order to achieve the above application purpose and solve the problems in the prior art, the technical scheme adopted by the application is:

[0007] A super-elastic film gripper, comprising a super-elastic film, a fixing component, a sealing plug, a gas guide pipe and a gas delivery pump, the super-elastic film comprises a cabin and a gas inlet, the outer surface of the gas inlet of the super-elastic film is pasted and connected with the fixing component; the inner surface of the gas inlet of the super-elastic film is interference fit connected with the sealing plug, the gas inlet is connected with the through hole of the fixing component; one end of the gas guide pipe is pasted and connected with the sealing plug, and the other end is sealingly connected with the gas delivery pump.

[0008] Further, the cabin is a spherical structure and is made of latex material; the gas inlet is a convex cone, and the outer surface of the gas inlet is pasted and connected with the conical through hole of the fixing component.

[0009] Further, the super-elastic film forms an enveloping effect on the target object after gripping.

[0010] Further, the fixing component is an arc structure and is made of polylactic acid material; and a conical through hole is arranged above the fixing component and matches the shape of the sealing plug.

[0011] Further, the fixing component can be flexibly installed on a mechanical arm or a translation stage.

[0012] Further, the sealing plug is a round table-shaped plug made of silicone rubber material, and the shape of the sealing plug matches the conical through hole of the fixing component.

[0013] Further, the gas guide pipe is a hollow circular pipe made of polyvinyl chloride material.

[0014] Further, the gas delivery pump is a device capable of generating gas pressure to deliver gas, and can control the expansion process and the contraction process of the super-elastic film through the gas guide pipe.

[0015] Further, the sealing plug, the gas guide pipe, the fixing component and the super-elastic film jointly ensure the air tightness of the contact part, and the gas in the super-elastic film only enters and exits through the gas guide pipe.

[0016] The application further discloses a gripping method of the super-elastic film gripper.

[0017] S1, before the execution of the grabbing process, the inner and outer air pressure of the super-elastic film is balanced, and it is in the original state;

[0018] S2, when the grabbing process is executed, the position of the flexible grabber is adjusted by controlling the mechanical arm or the translation stage; at the same time, the gas delivery pump starts to work, and the super-elastic film is inflated through the gas guide pipe, at this time the super-elastic film is inflated and expanded;

[0019] S3, continue to control the fixed part 2 through the mechanical arm or the translation stage to adjust the grabbing position of the super-elastic film grabber, so that the spherical chamber of the super-elastic film continuously approaches the target object;

[0020] S4, after the super-elastic film contacts the target object, the super-elastic film continues to approach the target object by controlling the mechanical arm or the translation stage, at this time the super-elastic film will produce adaptive deformation according to the surface shape of the contacted object, and finally form an envelope effect on the target object;

[0021] S5, when the target object is almost completely enveloped, control the gas delivery pump to enter the deflation process, and the super-elastic film is deflated and shrunk; at the same time, the mechanical arm or the translation stage is controlled to make the grabber continuously move towards the target until the expected grabbing depth is reached;

[0022] S6, the super-elastic film continues to deflate and shrink, and after the inner air pressure of the super-elastic film is balanced with the atmospheric pressure, the super-elastic film part of the flexible grabber envelops and grabs the target object, realizing the flexible grabbing function;

[0023] S7, after successfully grabbing the target object, the mechanical arm or the translation stage is controlled to carry the target object to the designated position, and then the gas delivery pump is inflated to make the super-elastic film expand, so as to release the target object;

[0024] S8, after completing a grabbing process, the gas delivery pump controls the super-elastic film to deflate to balance the inner and outer air pressure, and waits for the next grabbing task to be executed.

[0025] The present application utilizes the vacuum adsorption force and friction force formed between the super-elastic film and the target object to realize the enveloping grabbing of the target object. The super-elastic film is similar in shape to a balloon and is made of latex material, which can be divided into a spherical chamber and an inlet and outlet port. The inlet and outlet port is a convex conical port on the spherical surface, which can pass through the conical through hole of the fixed part, and the inner surface is connected with the interference fit of the sealing plug, and the outer surface is connected with the conical through hole of the fixed part. The spherical chamber has good elasticity, and after grabbing, it can adapt to the shape of the target object by relying on the elastic deformation of the super-elastic film itself, and form an enveloping effect on the target object. The sealing plug is a circular truncated cone plug made of silicone rubber material, which is matched with the conical through hole of the fixed part. The air duct is a hollow circular tube made of polyvinyl chloride material, which is connected with the sealing plug at one end and connected with the air pump at the other end, so as to realize the communication between the air pump and the spherical chamber of the elastic film. The fixed part is an arc-shaped structure made of polylactic acid material, which can limit the swing of the elastic film during grabbing and improve the stability of grabbing. The upper part has a conical through hole matched with the shape of the sealing plug, and can be flexibly installed on the mechanical arm or translation table, thereby realizing the overall movement of the grabber. The air pump is a device capable of generating air pressure to deliver gas, which can inflate and deflate the elastic film, thereby realizing the expansion and contraction of the elastic film.

[0026] The present application has the advantages of simple structure, easy manufacturing, and convenient replacement and maintenance of parts. Compared with the existing flexible grabber, the present application has the characteristics of simple operation, light weight, and low price. In addition, the super-elastic film is used as the actuator to contact the target object and realize the grabbing function, which is beneficial to the flexibility and safety of the flexible grabber. Based on the use method of the super-elastic film grabber, the elastic ability of the super-elastic film is used to produce adaptive deformation on the target object, greatly reducing the force applied to the surface of the target object, better adapting to the shape of the target object, realizing the enveloping grabbing of target objects of different shapes, and without subsequent energy supply after grabbing. The fixed part can be flexibly installed on the mechanical arm or translation table, thereby expanding the application range. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0028] Figure 1 is a structural schematic diagram of the present application.

[0029] Figure 2 is a sectional view of the present application.

[0030] Figure 3 is the adaptive deformation map of the object being compressed during the super-elastic membrane gripper grasping process.

[0031] Figure 4 is the envelope of the object being grasped by the super-elastic membrane gripper.

[0032] In the figure: 1, elastic membrane, 2, fixed part, 3, sealing plug, 4, air duct, 5, air pump, 6, grasping target. DETAILED DESCRIPTION

[0033] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0035] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0036] The relative arrangement of parts and steps, numerical expressions, and numerical values set forth in the examples herein are not intended to limit the scope of the application unless specifically stated otherwise. It is to be understood that the drawings are not necessarily to scale as the dimensions of the parts shown are for the purpose of illustration and description only and not to limit the scope of the application. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered within the scope of the present disclosure where appropriate. In all examples shown and discussed herein, any specific value should be interpreted as merely an example, and not as a limitation. Thus, other examples of the exemplary embodiments can have different values. It should be noted that like reference numerals and letters refer to like items in the several views of the drawings, and thus, once an item is defined in one view, it need not be discussed further in subsequent views.

[0037] As shown in Figure 1 , 2 An elastic film grabber includes an elastic film 1, a fixed component 2, a sealing plug 3, an air duct 4, and a gas delivery pump 5. The elastic film 1 is shaped like a balloon and made of latex material, and can be divided into a spherical chamber and an air inlet and outlet. The air inlet and outlet is a convex conical port on the spherical surface, which can pass through the conical through hole of the fixed component 2, and is connected with the sealing plug 3 in interference fit, and is connected with the conical through hole of the fixed component 2 in adhesive connection. The spherical chamber has good elasticity and can adapt to the shape of the target object after grabbing, and forms an envelope effect on the target object 6. The sealing plug 3 is a circular truncated cone plug made of silicone rubber material, and its shape matches the conical through hole of the fixed component 2. The air duct 4 is a hollow circular tube made of polyvinyl chloride material, and is connected with the sealing plug 3 at one end and connected with the gas delivery pump 5 at the other end, so as to realize the communication between the gas delivery pump 5 and the spherical chamber of the elastic film 1. The fixed component 2 is an arc-shaped structure made of polylactic acid material, which can limit the swing of the elastic film 1 during grabbing and improve the stability of grabbing. The conical through hole above it matches the shape of the sealing plug 3, and can be flexibly installed on a mechanical arm or a translation table, thereby realizing the overall movement of the grabber. The gas delivery pump 5 is a device capable of generating gas pressure to deliver gas, which can inflate and deflate the elastic film 1, thereby realizing the expansion and contraction of the elastic film 1. The elastic film 1, the fixed component 2, the sealing plug 3, and the air duct 4 work together to ensure good air tightness of the contact part, so that the gas in the elastic film 1 can only enter and exit through the air duct 4.

[0038] The present application relies on the friction and vacuum adsorption force of the elastic film 1 to realize the grabbing of the target object. The inflation and deflation process of the elastic film is the key to the grabbing process. The specific grabbing process is as follows:

[0039] (1) Before the execution of the grabbing process, the inner and outer air pressure of the elastic film is balanced, and it is in the original state;

[0040] (2) When the grabbing process is executed, the position of the flexible grabber is adjusted by controlling the mechanical arm or the translation stage; at the same time, the air supply pump 5 starts to work, and the elastic film 1 is inflated through the air guide pipe 4, at this time the elastic film 1 is inflated and expanded;

[0041] (3) Continue to control the fixed part 2 through the mechanical arm or the translation stage to adjust the grabbing position of the super-elastic film grabber, so that the spherical chamber of the elastic film 1 continuously approaches the target object 6;

[0042] (4) After the elastic film 1 contacts the target object, the elastic film 1 continues to approach the target object by controlling the mechanical arm or the translation stage, at this time the elastic film 1 will produce adaptive deformation according to the surface shape of the contacted object, and finally form an enveloping effect on the target object, as shown in Figure 3 ;

[0043] (5) When the target object is almost completely enveloped, control the air supply pump 5 to enter the deflation process, and the elastic film 1 is deflated and shrunk; at the same time, control the mechanical arm or the translation stage to make the grabber continuously move towards the target until the expected grabbing depth is reached;

[0044] (6) The elastic film 1 continues to deflate and shrink, and after the inner air pressure of the elastic film 1 is balanced with the atmospheric pressure, the elastic film part of the flexible grabber envelops and grabs the target object, realizing the flexible grabbing function, and the grabbing effect is as shown in Figure 4 ;

[0045] (7) After successfully grabbing the target object, control the mechanical arm or the translation stage to carry the target object 6 to the designated position, and then inflate the elastic film 1 by the air supply pump 5 to release the target object 6;

[0046] (8) After completing a grabbing process, deflate the elastic film 1 to balance the inner and outer air pressure by the air supply pump 5, and wait for the next grabbing task.

[0047] When the grabber is used for grabbing experiments, the grabbing force, the pressure borne by the target object, and the success rate of grabbing are counted: when grabbing daily objects such as water cups, scissors, eggs and other fragile and deformable objects, the grabber shows high adaptability, and the maximum grabbing force reaches 650g, which is 13 times the grabbing force of the grabber itself. At the same time, the maximum pressure borne by the target object is measured, and the result shows that the maximum pressure borne by the target object is less than 8kPa; in addition, the success rate of grabbing a plastic ball with a diameter of 60mm and a mass of 12g is tested, and when the grabbing depth is 19mm, the success rate of grabbing reaches 88%; the above grabbing results prove that the grabber can fully exert the advantages of the super-elastic film, and has high bearing capacity and reliability while fully protecting the target object.

[0048] The advantage of the present application is that a super-elastic film gripper comprises an elastic film, a fixed component, a sealing plug, an air duct and a gas delivery pump, characterized by simple structure, easy manufacturing and convenient replacement and maintenance of parts. Compared with existing flexible grippers, the present application uses a super-elastic film as an actuator to contact the target object, and uses the vacuum adsorption force and friction force formed by the contact surface to realize the enveloping gripping function, which is conducive to the flexibility and safety of the flexible gripper; based on the use method and characteristics of the super-elastic film gripper, the present application can better adapt to the shape of the target object, realize the enveloping gripping of target objects of different shapes without damaging the objects as much as possible, and does not require subsequent energy supply after gripping; the fixed component can be flexibly installed on a mechanical arm or a translation stage, thereby expanding the application range. Compared with existing flexible grippers, the present application has the characteristics of simple operation, overall lightness, low price and the like.

Claims

1. A gripping method for a superelastic membrane gripper, characterized in that, The superelastic membrane gripper includes a superelastic membrane, a fixing component, a sealing plug, an air duct, and an air pump. The superelastic membrane includes a chamber and an air vent. The outer surface of the superelastic membrane air vent is bonded to the fixing component. The inner surface of the superelastic membrane air vent is interference-fitted to the sealing plug. The air vent is connected to a through hole in the fixing component. One end of the air duct is bonded to the sealing plug, and the other end is sealed to the air pump. The cabin has a spherical structure and is made of latex material; The fixing component has an arc-shaped structure and is made of polylactic acid material; It has a conical through hole at the top, which matches the shape of the sealing plug; The sealing plug is a frustum-shaped plug made of silicone rubber material, and its shape matches the conical through hole of the fixing component; The air guide tube is a hollow circular tube made of polyvinyl chloride material; The gas pump is a device that can generate gas pressure to transport gas, and can control the expansion and contraction process of the superelastic membrane through the gas delivery pipe. The sealing plug, air guide tube, fixing component, and superelastic membrane work together to ensure the airtightness of the contact part, and the gas inside the superelastic membrane only enters and exits through the air guide tube; The scraping method includes the following steps: S1. Before the gripping process is executed, the air pressure inside and outside the superelastic membrane is balanced and in its original state. S2. When performing the gripping process, the position of the flexible gripper is adjusted by controlling the robotic arm or translation stage; at the same time, the air pump starts to work and inflates the hyperelastic membrane through the air tube, at which time the hyperelastic membrane inflates and expands. S3. Continue to control the fixed components through the robotic arm or translation stage to adjust the gripping position of the superelastic membrane gripper, so that the spherical chamber of the superelastic membrane continuously approaches the target object. S4. After the superelastic membrane comes into contact with the target object, the robotic arm or translation stage continues to control the superelastic membrane to move closer to the target object. At this time, the superelastic membrane will undergo adaptive deformation according to the surface shape of the contact object, and finally form an enveloping effect on the target object. S5. When the target object is almost completely enclosed, control the air pump to start the deflation process, and the superelastic membrane deflates and contracts; at the same time, manipulate the robotic arm or translation stage to make the gripper continue to move towards the target until the expected gripping depth is reached. S6. The superelastic membrane continuously deflates and contracts. After the air pressure inside the superelastic membrane is balanced with the atmospheric pressure, the superelastic membrane of the flexible gripper partially envelops and grips the target object, thus realizing the flexible gripping function. S7. After successfully grabbing the target object, control the robotic arm or translation table to move the target object to the designated position, and then the air pump will inflate the superelastic membrane again to release the target object. S8. After completing one grasping process, the air pump controls the superelastic membrane to release air until the internal and external air pressures are balanced, and then waits to execute the next grasping task.

2. The method according to claim 1, characterized in that: The vent is a protruding cone shape, and the outer surface of the vent is bonded to the conical through hole of the fixing component.

3. The method according to claim 1, characterized in that: The superelastic membrane forms an envelope effect on the target object after it grasps it.

4. The method according to claim 1, characterized in that: The fixed component can be flexibly installed on the robotic arm or translation table.

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