CN111452066A - A fully flexible bionic pneumatic manipulator - Google Patents

Abstract

A kind of all flexible bionical pneumatic type mechanical arm, is formed by at least one mechanical arm unit, every said mechanical arm unit includes bionical actuating system and actuating system, bionical actuating system includes a cylindrical shell and at least three air cavities of the corrugated structure made of flexible material of corrugated structure made of flexible material, the whole cylindrical shell presents the trunk structure, the appearance of the air cavity is the hollow cycle reducing solid of revolution, many air cavities are arranged in the cylindrical shell in parallel, cylindrical shell and air cavity are all one end closed another end opening, the closed end II outer wall of the air cavity is bonded with the closed end I inner wall of the cylindrical shell together, except that the bond, air cavity and cylindrical shell, air cavity and air cavity are all not contacted in the initial condition; the driving system comprises a pneumatic driver, the pneumatic driver is provided with a plurality of air inflation pipelines, and the air inflation pipelines are respectively connected with the opening end II of the air cavity and the opening end I of the cylindrical shell. The gripping capacity cavity is flexible to use, simple in structure and easy to operate.

Description

A fully flexible bionic pneumatic manipulator

technical field

The invention relates to a pneumatic manipulator, in particular to a fully flexible bionic pneumatic manipulator, which belongs to the field of robot design.

Background technique

Although traditional robots have been widely used in industry, medicine, construction and other fields, there are still some insurmountable technical problems such as large motor drive inertia, cumbersome motion, and difficult control of rigid body and fully flexible interaction. These shortcomings limit the application scope of traditional robots, such as the grasping of fragile items, underwater operations, confined spaces, and so on.

With the continuous development of computer technology, control technology, and artificial intelligence technology, robots are playing an increasingly important role in intelligent manufacturing, medical technology, aerospace and other fields. Intelligent robots are moving towards natural interaction, bionic technology, and human-machine collaboration. direction is developing rapidly.

In recent years, with the rise of bionic technology and smart materials, scientists have used flexible smart materials to imitate biological structures and develop fully flexible robots based on biological motion principles. By changing the original shape and size to achieve crawling and twisting, it has a wide range of application prospects in unstructured environments, making up for the shortcomings of traditional robots in restricted space movement.

Grasping operation is an important ability for robots to perform various complex tasks. There are two main driving modes of the fully flexible manipulator: intelligent material driving and pneumatic driving. Among them, the pneumatically driven fully flexible manipulator mainly combines 3D printing technology to print the driver mold, injects superelastic silicone material to make the fully flexible robot driver, and deforms the driver by applying air pressure. Compared with the fully flexible manipulator driven by intelligent materials, the pneumatically driven fully flexible manipulator has larger deformation, faster response and more flexible movement, and is suitable for a wider range of scenarios.

A known multi-degree-of-freedom pneumatic flexible manipulator. It includes a multi-degree-of-freedom flexible actuator, a circular base and a sealed base. The circular base is provided with three fixed ends at equal intervals in the circumferential direction, and each fixed end has three tracheal through holes and a wire placement hole, and each fixed end has a port Extend outward to form a flange, the sealing base is embedded in the flange, and each fixed end is installed with a multi-degree-of-freedom flexible actuator through the sealing base. A cylindrical cavity is provided; the three air inlets of the sealing base are respectively inserted into the three air passages, and the cylindrical seat of the sealing base is inserted into the cylindrical cavity; Inertial sensor. The multi-degree-of-freedom pneumatic flexible manipulator has a compact structure, and when the multi-inflatable component is inflated, it can perform a specified angle bending operation with multiple degrees of freedom, which solves the problem that the traditional pneumatic actuator cannot perform multi-degree-of-freedom operation and angle feedback. This multi-DOF pneumatic flexible manipulator has the following shortcomings:

1. The structure is more complicated, involving multiple rigid connecting parts, and the airway is only provided with a trapezoidal bending structure that increases the tensile area on the side close to the outer surface, resulting in that for each airway, inflation can only provide one direction of force, thus greatly limiting the degrees of freedom of the "multi-degree-of-freedom flexible actuator".

Second, the grasping method is relatively simple, only a combination of several "multi-degree-of-freedom flexible actuators" can be adopted, and the grasping operation can only be realized for the object placed in the center of the manipulator. A multifunctional flexible manipulator is also known, comprising at least one set of three-chamber conjoined flexible arms, wherein the three-chamber conjoined flexible arms are composed of three hoses and three independent flexible grippers, each of the flexible grippers. The inner cavities of the flexible grippers are all hollow structures, one end of each hose is connected with the inner cavity of the corresponding flexible gripper, and the other end is connected with a first driving device for supplying air to the hose. In the present invention, the corresponding hoses are inflated to different degrees by the first driving device, so that the flexible gripper of the three-chamber conjoined flexible arm can be bent and deformed, and a joint bending flexible arm similar to a human hand can be formed. The corresponding hoses are deflated/pumped to different degrees, so that the flexible gripper can return to its original position. By setting up multiple groups of three-chamber conjoined flexible arms to complete the pick-and-place action, lifting action, tightening/releasing action and multi-directional twisting of the item, the labor burden can be reduced and the production efficiency can be improved. The structure of the "three-chamber conjoined flexible arm" (hereinafter referred to as the conjoined arm) in the "a multifunctional flexible manipulator" has the following shortcomings: 1. The inner cavity of the flexible gripper and the outer wall of the flexible gripper in the conjoined arm It is not set into a bellows structure, its telescopic deformation ability is poorer than that of the patent, and the deformation amount is small. 2. There are many rigid auxiliary structures. For example, when realizing the operation of "screwing the bottle cap", complex rigid machinery such as a rotating motor needs to be used, which is inconvenient to use.

It is also known that a pneumatic flexible manipulator for deep well rescue includes a flexible telescopic arm, a mechanical gripper, an inflating and deflating device and a control device; the flexible telescopic arm is a long trachea made of soft elastic There are three parallel and independently closed elongated airbag cavities in the length direction; one end of the airbag cavity is closed, and the other end is open, which is connected with the inflation and deflation device; the control device is controlled and connected with the inflation and deflation device; the mechanical gripper includes several A mechanical claw and a hinge, one end of the mechanical claw is connected with the hinge, and the hinge is rotated by a rotating motor to drive the mechanical claw to swing; the hinge is fixedly connected with one end of the flexible telescopic arm. The invention is small in size, convenient in operation, reliable in performance and low in cost, and can replace rescuers to enter into narrow deep wells to perform rescue operations. The problems of this "a pneumatic flexible manipulator for deep well rescue" are as follows: 1. The number of airbag cavities is fixed at three, and the number of airbag cavities cannot be flexibly adjusted according to needs. 2. The airbag cavity is only provided with a tooth-like structure on one side close to the outer surface of the telescopic arm, while the other side is not designed with a tooth-like structure, so that the bending direction of each airbag cavity is limited after inflation, and the degree of freedom of the entire telescopic arm is limited. limit. 3. The rigid mechanical gripper driven by the motor is used as the gripping method, which cannot realize soft gripping, and the structure is more complicated.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned shortcomings of the prior art, the present invention provides a fully flexible bionic pneumatic manipulator, which has a strong grasping ability, is more flexible in use, has a simple structure and is easy to operate.

The technical solution adopted by the present invention to solve the technical problem is as follows: it is composed of at least one manipulator unit, each manipulator unit is controlled independently, and the manipulator units are used in combination, and each manipulator unit includes a bionic execution system and a driving system. The execution system includes a cylindrical shell with a bellows structure made of flexible materials and at least three air cavities with a bellows structure made of flexible materials. The cylindrical shell and the air cavity are both closed at one end and open at the other end. It has an elephant trunk structure, the shape of the air cavity is a hollow periodic variable diameter revolving body, a plurality of air cavities are arranged in parallel and are set together in the cylindrical shell, and the outer wall of the closed end II of the air cavity is glued to the inner wall of the closed end I of the cylindrical shell. Connected together, except for the bonding place, the air cavity and the cylindrical shell, the air cavity and the air cavity are not in contact in the initial state; the driving system includes a pneumatic driver, and the pneumatic driver has a plurality of inflatable pipes, and the inflatable pipes are respectively connected with the gas. The open end II of the cavity and the open end I of the cylindrical shell are connected.

Compared with the existing fully flexible bionic manipulator, the fully flexible bionic pneumatic manipulator of the present invention is mainly composed of a bionic execution system and a driving system. The air cavity is driven by a pneumatic driver, and the attitude change can be realized only by controlling the air pressure value of different air cavities. The structure is very simple and the operation is very convenient. Secondly, and more importantly, the flexibility of the manipulator of the present invention is significantly improved. From the aspect of bionics, the trunk-shaped air cavities can achieve different expansion and contraction respectively, and the cylindrical shell can directly obtain different expansion and contraction. The interaction force between the cavity and the air cavity caused by different degrees of deformation, the force between the air cavity and the cylindrical shell due to the connection position, the difference and cooperation between the air cavity and the cylindrical shell in shape, the above factors play a comprehensive role, It can highly restore the behavior of the real elephant trunk, and even obtain more and more detailed bionic movements, so that the grasping ability is significantly improved, and it is capable of performing various complex tasks; in terms of the number of air cavities, the individual The data will enable the fully flexible bionic manipulator to have different degrees of freedom, which can be flexibly matched according to the usage scenarios, so as to complete specific grasping tasks under the premise of maximizing cost savings; from the perspective of the combination of fully flexible pneumatic manipulators, different The number of manipulators can achieve different grasping effects: a single manipulator can achieve curling grasping, and a combination of multiple manipulators can achieve gripping grasping, etc.

Specifically, the beneficial effect analysis of the present invention compared with the prior art is as follows:

Compared with the existing "a multi-degree-of-freedom pneumatic flexible manipulator", on the one hand, each manipulator unit in the application of the present invention can achieve 360° bending, and has higher flexibility. On the other hand, the present invention can also realize grasping in a crimping manner by only relying on one robot unit. And when multiple mechanical units are used in combination, because the air cavity of the manipulator unit is directly connected to the air guide channel in the inflatable device, there is no constraint of rigid connecting parts, and the air cavity and the flexible cylindrical shell are connected by bonding, so the unit The number and the number of air cavities in each manipulator unit can be adjusted according to needs, and the flexibility is higher.

Compared with the existing "a multifunctional flexible manipulator", firstly, the present invention adopts the bellows structure to design the cylindrical shell and the air cavity, which ensures a large amount of deformation; During the operation of the "cover", it can be realized by simply controlling the bending of the manipulator unit through air pressure, which is very convenient and efficient.

Compared with the existing "a pneumatic flexible manipulator for deep well rescue", first of all, in the present invention, the air chamber and the cylindrical shell are connected by bonding, so it is convenient to adjust the number of air chambers as needed. Secondly, in the present invention, each air cavity is designed as a periodically variable diameter revolving body, and the force required to bend in all directions is equal, so more degrees of freedom can be obtained after inflation. Then, in the present invention, the manipulator unit is made of fully flexible material, which can realize soft grasping, which is safe and simple.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

FIG. 1 is a schematic diagram of the overall structure of an embodiment of the present invention.

Figure 2 is a cross-sectional view of one embodiment of the present invention.

3 is a longitudinal cross-sectional view of an embodiment of the present invention.

FIG. 4 is a schematic diagram of the overall structure of an air cavity in an embodiment of the present invention.

5 is a schematic longitudinal cross-sectional view of an air cavity in an embodiment of the present invention.

FIG. 6 is a schematic diagram of the overall structure of a cylindrical housing in an embodiment of the present invention.

FIG. 7 is a schematic longitudinal cross-sectional view of a cylindrical housing in an embodiment of the present invention.

FIG. 8 is a schematic diagram of a simulation result of an embodiment of the present invention under pneumatic excitation.

In the figure: 1. Cylindrical shell, 1-1, closed end I, 1-2, open end I, 2, air cavity, 2-1, closed end II, 2-2, open end II.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1:

Figures 1 to 8 show schematic structural diagrams of a preferred embodiment 1 of the present invention. A fully flexible bionic pneumatic manipulator in Figures 1-3 is composed of a manipulator unit, and the manipulator unit includes Bionic Execution System and Drive System. Wherein, the bionic execution system includes a cylindrical shell 1 with a bellows structure made of flexible materials and three air cavities 2 with a bellows structure made of flexible materials. In the housing 1, the air cavity 2 is preferably distributed in the center of the inner space of the cylindrical housing 1. Such a design is convenient for the controllability of the degree of freedom of the flexible hand under the condition of a certain number of air cavities 2; The preferred design is that the angle between adjacent air cavities 2 bisects the circumference, and the design of bisecting the circumference is also convenient for the best controllability of the degree of freedom of the flexible hand under the condition of a certain number of air cavities 2; the opening of the air cavity 2 The direction is consistent with the opening direction of the cylindrical shell 1. The outer wall of the closed end II2-1 of the air cavity 2 is bonded to the inner wall of the closed end I1-1 of the cylindrical shell 1. Except for the bonding point, the air cavity 2 and the cylindrical shell are bonded together. The shell 1 , the air cavity 2 and the air cavity 2 are not in contact with each other in the initial state. In addition, the driving system provides power for the bending of the manipulator; the driving system includes a pneumatic driver, and the pneumatic driver has three inflatable pipes, and the three inflatable pipes are respectively connected with the open ends II2-2 of the three air chambers 2. The air pressure can be controlled independently, and the open end I1-2 of the cylindrical shell 1 is sealed with the inflator through a conventional connecting structure such as a clamp. Preferably, the radius of the inflation pipe is the same as the radius of the air cavity 2 , so as to achieve a sealed connection with the air cavity 2 .

As shown in Figures 4 to 5, the air cavity 2 is a hollow periodic variable diameter revolving body with one end closed and one end open. This shape structure can make the air cavity 2 preferentially elongate longitudinally rather than laterally when inflated, and can make the manipulator Elements have the advantage of large deformations. The two ends are the closed end II2-1 and the open end II2-2 respectively. The closed end II2-1 is directly bonded to the cylindrical shell 1. In order to achieve overall flexibility, silicone rubber is preferably used as the adhesive, and the type of silicone rubber can be It is GD401, or PDMS (polydimethylsiloxane); the open end II2-2 connects the drive system. When the air pressure inside the air cavity 2 increases, the air cavity 2 is preferentially elongated in the longitudinal direction due to the restraining effect of the bellows structure.

As shown in Figures 6 to 7, the cylindrical shell 1 is also closed at one end and open at the other end, and the overall shape is a trunk structure. The bending posture of the cylindrical shell 1 depends on the air pressure in the three air chambers 2 . When the cylindrical shell 1 is subjected to pressure from the deformed air cavity 2, it will stretch due to the force, and the farther the distance between each part of the cylindrical shell 1 from the deformed air cavity 2, the smaller the elongation.

FIG. 8 is a simulation result diagram of Embodiment 1 of the present invention under pneumatic excitation. Using abaqus CAE as the simulation software, the number of airbags in the simulation model is 3, and only one of the air chambers 2 is fed with gas, so that the air pressure in the air chamber 2 is increased from 0Mpa to 0.1Mpa. The manipulator will have a curved posture as a whole.

As a preferred design solution of this embodiment, both the inner air cavity 2 and the outer cylindrical shell 1 are made of polydimethylsiloxane (PDMS) using 3D printing technology. Substitute other flexible materials, such as AB glue, to ensure the flexibility and environmental friendliness of the overall structure, so that the manipulator can well adapt to the surrounding environment, quickly complete large deformations, and then achieve soft grasping.

The number of air cavities 2 in the present embodiment 1 can also be other numbers greater than three. When matched, the pneumatic driver has the same number of inflation pipes; the entire cylindrical shell 1 can be realized by controlling the air pressure changes of several internal air cavities 2 , so that the grasping operation can be realized in a crimping manner.

The working principle of Embodiment 1 of the present invention is as follows:

When gas is filled into the air cavity 2, the air pressure in the air cavity 2 will gradually increase. Because the air cavity 2 is restricted by its own bellows structure, the entire air cavity 2 will preferentially deform in the length direction, and the overall length will increase; and because the air cavity 2 is connected with the flexible cylindrical shell 1 of the external bellows structure, when the air cavity 2 When the cavity 2 is stretched, the connection between the cylindrical shell 1 and the air cavity 2 will be stressed, and then the cylindrical shell 1 will be elongated. Different air chamber 2 pressure combinations can make the fully flexible bionic pneumatic manipulator present different postures. For example, when each air cavity 2 is filled with the same amount of gas, the manipulator as a whole will extend straight ahead, which can achieve the purpose of approaching the object to be grasped; when only a few air cavities 2 are filled with gas, the rest The air cavity 2 is not inflated. At this time, because the cylindrical shell 1 is subjected to uneven pressure from each air cavity 2, the entire manipulator will bend toward the air cavity 2 that is not filled with gas. Combined with this feature, when the overall length of the manipulator is sufficient, the behavior of the real elephant trunk can be highly restored, and the grasping can be realized in a curling manner.

The overall length of the manipulator can be flexibly changed according to the needs of the application scenario. When the length of the manipulator is not enough to realize grasping in a crimping manner, a fully flexible bionic pneumatic manipulator of the present invention can also be composed of a plurality of manipulator units, each manipulator unit is controlled independently, and one of the multiple manipulator units It can be used in combination to realize the grasping operation in the way of clamping. For example, Embodiment 2 and Embodiment 3 are structural solutions in which the number of manipulator units is three and four, respectively. The second embodiment is a combination of three manipulator units, which can realize the action of "twisting". Taking a round bottle cap as an example, at this time, the three manipulator units are divided into three corners of an equilateral triangle, and the inner side of each manipulator unit is close to the bottle cap; then the air pressure of the air cavity 2 in each manipulator unit is changed. , so that each manipulator unit is bent along the tangential direction of the cap; under the action of friction, the cap will be twisted; restore the air pressure in the air chamber 2 to the initial state, and each manipulator will return to the initial position; repeat the above operations , and finally complete the action behavior of "twisting the bottle cap". In the third embodiment, four manipulator units are respectively occupied at the four corners of the square. By controlling the air pressure of different air cavities 2 in each manipulator unit, all four manipulator units are bent toward the center of the square, so that the four manipulator units can be clamped. Objects placed in the center.

The fully flexible bionic pneumatic manipulator of each embodiment of the present invention is mainly based on 3D printing technology and silicone rubber fluid molding technology, and is specifically manufactured according to the following steps:

First, use the Abaqus CAE finite element simulation software to analyze the number and size of the corrugations of the air cavity 2 and the cylindrical shell 1, the number and distribution of the air cavity 2, and the thickness of the cylindrical shell 1, etc., gradually optimize the size parameters, and comprehensively consider multi-angle factors. , and finally determine the structure.

After determining the relevant structure and parameters, use three-dimensional modeling software (such as SolidWorks, AutoCAD, 3D MAX, etc.) to design the mold of the air cavity 2 , and then design the mold of the cylindrical shell 1 .

After the mold design is completed, the file format is converted, and the molds are printed one by one in the 3D printer. In order to prevent the mold from being deformed during the injection of materials and solidification, it is necessary to print multiple copies of each mold.

At the end of the mold printing, the surface of the mold needs to be finely ground to prevent the defects in the 3D printing process from affecting the molding of the robot sample. After each component is cured and demolded, silicone rubber is used as an adhesive to connect the closed end II2-1 of the air cavity 2 to the inner surface of the cylindrical shell 1, and to assemble with the relevant drive system, and finally the complete system of the present invention is obtained. Flexible bionic pneumatic manipulator.

To sum up, the significant advantages of the present invention compared with the prior art are summarized as follows:

1) The fully flexible bionic manipulator itself of the present invention has a simple structure, and only needs to control the air pressure values of different air chambers 2 to realize the posture change, and the operation is convenient.

2) The fully flexible bionic manipulator of the present invention is flexible to use. From the aspect of the number of air cavities 2, different numbers of air cavities 2 will enable the fully flexible bionic manipulator to have different degrees of freedom, which can be flexibly matched according to the usage scenarios, so that it can complete specific tasks on the premise of maximizing cost savings. crawl task. In terms of combination, different numbers of manipulator units can achieve different grasping effects: a single manipulator unit can realize curling and grasping; a combination of multiple manipulator units can realize gripping and grasping, etc.

3) The fully flexible bionic manipulator of the present invention adopts a fully flexible design and is highly environmentally friendly. On the one hand, because the chemical properties of PDMS are generally inert, and PDMS is hydrophobic, it has better adaptability than traditional rigid manipulators in acidic conditions, underwater and other environments, and is non-toxic, non-flammable, and suitable for a wide range of conditions. On the other hand, the fully flexible structure enables the manipulator to passively deform to adapt to changes in the external space, which is more flexible than the traditional rigid manipulator. In addition, the fully flexible structure enables the manipulator to achieve soft grasping, which can better protect the object to be grasped.

4) The fully flexible bionic manipulator of the present invention is prepared by using 3D printing technology, and the raw materials are cheap, which is convenient for large-scale preparation.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications and equivalent changes made to the above embodiments according to the technical essence of the present invention shall fall into the scope of the present invention. within the scope of protection of the invention.

Claims (7)

1. The utility model provides a full flexible bionical pneumatic type manipulator, comprises at least one manipulator unit, and every manipulator unit individual control uses characterized by between the manipulator unit in the combination: each manipulator unit comprises a bionic execution system and a driving system,

the bionic execution system comprises a cylindrical shell (1) with a corrugated pipe structure made of flexible materials and at least three air cavities (2) with the corrugated pipe structure made of the flexible materials, wherein the cylindrical shell (1) and the air cavities (2) are of structures with one closed end and the other open end, the whole cylindrical shell (1) is of a trunk structure, the appearance of the air cavities (2) is a hollow periodic variable-diameter revolving body, a plurality of air cavities (2) are arranged in parallel and are jointly arranged in the cylindrical shell (1), the outer wall of the closed end II (2-1) of the air cavity (2) is bonded with the inner wall of the closed end I (1-1) of the cylindrical shell (1), and the air cavities (2) are not in contact with the cylindrical shell (1) and the air cavities (2) at an initial state except for bonding positions;

the driving system comprises a pneumatic driver, the pneumatic driver is provided with a plurality of air charging pipelines, the air charging pipelines are respectively connected with the opening ends II (2-2) of the air cavities (2) one by one, and the opening end I (1-2) of the cylindrical shell (1) is connected with an air charging device in a sealing mode.

2. The fully flexible bionic pneumatic manipulator according to claim 1, which is characterized in that: the included angle between every two air cavities (2) is halved on the circumference.

3. The fully flexible bionic pneumatic manipulator according to claim 1 or 2, which is characterized in that: the air cavity (2) is distributed in the center of the inner space of the cylindrical shell (1).

4. The fully flexible bionic pneumatic manipulator according to claim 3, which is characterized in that: the adhesion between the air cavity (2) and the cylindrical shell (1) is realized by adopting silicon rubber as an adhesive.

5. The fully flexible bionic pneumatic manipulator according to claim 4, which is characterized in that: the flexible material for preparing the air cavity (2) and the cylindrical shell (1) is polydimethylsiloxane.

6. The fully flexible bionic pneumatic manipulator according to claim 1 or 2, which is characterized in that: the manipulator is composed of three manipulator units, and the three manipulator units are respectively arranged at the positions of three corners of an equilateral triangle.

7. The fully flexible bionic pneumatic manipulator according to claim 1 or 2, which is characterized in that: the manipulator is composed of four manipulator units, and the four manipulator units respectively occupy the positions of four corners of a square.

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