CN114770490B

CN114770490B - Soft manipulator based on cross-modal touch sensor and bubble driver

Info

Publication number: CN114770490B
Application number: CN202210515209.6A
Authority: CN
Inventors: 项超群; 云涛; 彭俊杰; 李靖; 孙志华; 王淳锋; 管贻生; 朱海飞
Original assignee: Guangdong University of Technology
Current assignee: Guangdong University of Technology
Priority date: 2022-05-11
Filing date: 2022-05-11
Publication date: 2023-06-09
Anticipated expiration: 2042-05-11
Also published as: CN114770490A

Abstract

The invention discloses a soft operating arm based on a cross-mode touch sensor and a bubble driver. The invention has safe man-machine interaction and infinite freedom degree, and improves the motion capability of the mechanical arm; meanwhile, a soft pneumatic finger with transmembrane state touch sensing is carried, so that not only can self-adaptive grabbing be realized, but also a transmembrane state touch sensor can be utilized to realize multifunctional sensing, and whether a soft manipulator contacts an object or not is sensed; sensing whether the soft pneumatic finger successfully grabs the object or not, and monitoring the object grabbing stability in real time in the process of grabbing the object and carrying; the contact force in the grabbing process can be sensed, and the grabbing force output can be accurately controlled, so that the object can be safely grabbed.

Description

Soft manipulator based on cross-modal touch sensor and bubble driver

Technical Field

The invention relates to the technical field of mechanical arms and robots, in particular to a soft operating arm based on a cross-mode touch sensor and a bubble driver.

Background

Compared with the traditional rigid robot, the soft robot has flexibility, self-adaptability, man-machine interaction safety and biocompatibility, has wide application prospect in the industries of agriculture, food, medical treatment and the like, and the grabbing of fragile and easily damaged objects (such as fruits, vegetables and biological tissues) requires the soft clamp holder and the operating arm to be self-adaptively grabbed and realize automatic carrying operation; meanwhile, the multi-finger hand is used as a substitute tool for a human hand, and needs to be flexible enough and have a touch sensing function so as to adapt to unstructured complex contact environments.

For a mechanical arm driver, the degree of freedom of the traditional mechanical arm is less due to the limitation of rigid materials, and corresponding sensors are required to be added for increasing the degree of freedom, so that the complexity of a system is increased, and a great potential safety hazard exists in the human-computer interaction process; for the end effector, the biggest difference between the soft hand and the rigid manipulator is that the body material is flexible, and the soft material has more complex and rich response characteristics than the rigid material, so that the soft hand not only brings functional flexibility and compliance, but also has more possibility in the design and control method of the soft hand. As a branch in the field of soft robots, soft hands are rapidly developing, and by virtue of the performance advantages of good active-passive adaptability, safety, complex environment adaptability and the like, important application values are exerted in various fields of production and life, in the aspect of soft touch sensing, the application and commercialization of the existing touch sensing technology are obviously lagged, the obtained research results mostly stay in a laboratory stage, and compared with the vision sensing technology, the defect is more obvious, so that a durable, reliable and universal soft touch sensor basically does not appear in the domestic and foreign markets, and a soft operation arm based on a cross-mode touch sensor and a bubble driver is proposed.

Disclosure of Invention

It is an object of the present invention to provide a soft manipulator arm based on a cross-modal tactile sensor and a bubble driver that addresses the above-described deficiencies in the art.

In order to achieve the above object, the present invention provides the following technical solutions: the utility model provides a soft operation arm based on stride modal touch sensor and bubble driver, includes square acrylic fixed plate, triangle-shaped acrylic backup pad and bubble driver, bubble driver sets up each other at triangle-shaped acrylic backup pad, and bubble driver all is provided with the spring each other, and the both ends of spring and the one side fixed connection that triangle-shaped acrylic backup pad is close to each other, and the top triangle-shaped acrylic backup pad's lateral wall and square acrylic fixed plate's fixed surface are connected, the bottom surface of triangle-shaped acrylic backup pad has three soft pneumatic fingers through screw fixed mounting, and the top of soft pneumatic finger all is provided with pneumatic finger air inlet, and one side that soft pneumatic finger is close to each other all is provided with soft film, and one side that soft film is close to each other all is provided with the inside columnar protrusion of a plurality of equidistance arranged soft film, and one side that soft film is kept away from each other all is provided with the camera module.

As a preferable scheme of the invention, the top and the bottom of the bubble driver are respectively provided with a bubble driver air outlet and a bubble driver air inlet.

As a preferable scheme of the invention, the three bubble drivers are distributed at the positions of the three vertexes of the triangular acrylic supporting plate at equal intervals around the center, and the air pressure adjustment of the bubble drivers cannot be too high, otherwise, the bubble drivers are disabled.

As a preferable scheme of the invention, the three springs are distributed at the center of the border of the triangular acrylic supporting plate to play a supporting role.

As a preferable scheme of the invention, the three soft pneumatic fingers are equidistantly distributed around the center at the positions of three vertexes at the bottom of the triangle acrylic support plate at the bottom.

As a preferable scheme of the invention, the camera module is connected with a control system of the mechanical arm, the pneumatic finger air inlet at the upper end of the soft pneumatic finger is connected with the air pressure adjusting device, and the air pressure adjusting device controls the air pressure so as to avoid damaging the object to be grasped.

As a preferred embodiment of the invention, the camera module integrates a lighting device, which is able to capture images without an external light source.

As a preferable scheme of the invention, the camera module further comprises a cable, a mounting frame, a camera, a lamp bead, an acrylic sheet, transparent gel and a white round marker, wherein the cable is mounted on one side of the mounting frame far away from the soft film, the camera is mounted in the inner cavity of the mounting frame, the acrylic sheet, the lamp bead and the transparent gel are all arranged in the inner cavity of the mounting frame, the acrylic sheet is positioned between the lamp bead and the transparent gel, and the white round marker is arranged on one end of the columnar protrusion in the soft film far away from the soft film.

As a preferable scheme of the invention, the invention also comprises the following using flow:

three bubble drivers are equidistantly distributed at the positions of three vertexes of a triangular acrylic supporting plate around the center to play a driving role, the bubble drivers adopt PE plastic films as main materials, the PE plastic films are divided into a plurality of telescopic small bubbles by the triangular acrylic supporting plate after through holes, three springs are distributed at the positions of the edge line center of the triangular acrylic supporting plate to play a supporting role, axial expansion and contraction can be realized by inflating and deflating the single bubble drivers, and a driving system formed by the bubble drivers can be bent for a certain angle by providing different air inflow rates, so that the bending motion of an infinite degree of freedom of a mechanical arm is realized;

secondly, a transmembrane state touch sensor system, a camera module and a soft film internal columnar protrusion) are carried on the soft pneumatic finger part: three soft pneumatic fingers are equidistantly distributed around the center, a transmembrane tactile sensor system and columnar protrusions in a soft film are carried on fingertips of the soft pneumatic fingers, a camera module for collecting optical signals is arranged on the back of the fingertips of the soft pneumatic fingers, the camera module is connected with a control system of a mechanical arm, the soft pneumatic fingers are connected with an air pressure adjusting device through an air pressure inlet of the pneumatic fingers, the air pressure adjusting device controls the air pressure so as to avoid damaging a gripped object, the soft film collects deformation images of the columnar protrusions in the soft film by using the camera module, whether the soft pneumatic fingers contact the object or not is sensed through conversion from a touch mode to a visual mode, meanwhile, whether the object and the object are successfully gripped or not can be sensed, after the texture of the object is known, the grabbing force can be judged according to the shape of the tactile sensor, and the air pressure of the input soft pneumatic fingers is adjusted so that different grabbing forces are realized;

supplement to transmembrane tactile sensor systems: the camera module is integrated with the lighting device, an image can be captured under the condition of no external light source, a plurality of columnar protrusions are arranged on the side face of the soft film, the camera module is connected with the control system, when an object is captured, the soft film on the fingertip of the soft pneumatic finger is extruded, the soft film is deformed to drive the columnar protrusions in the soft film to displace, at the moment, the camera module shoots an image after the columnar protrusions in the soft film displace, the image is then transmitted to the control system, and the control system can acquire the contact force and the geometric information of the object by using an image processing method.

In the technical scheme, the invention has the technical effects and advantages that:

1. first, for the driving part, the main material of the bubble driver adopts PE plastic film, which has the advantages of low cost, light weight and the like compared with the traditional manufacturing material of the rigid mechanical arm. The manufacturing method of the bubble driver is simple, an acrylic plate with a through hole is utilized to form a bubble shape, a series of contractible units are created, and through experimental analysis, the maximum contraction amount of the bubble driver can reach 43.1%, the maximum stress can reach 894MPa, which is equivalent to that the bubble driver can lift the load which is 1000 times of the self weight (5.39 g); and secondly, the end effector is a soft pneumatic finger carrying a cross-mode touch sensor, the touch sensor is low in cost, simple to manufacture and easy to assemble, the 3D printing technology is utilized for manufacturing, the tactile super-resolution is achieved, the gap in the field of cheap, compatible and customizable touch sensors at present is filled, the whole end effector has self-adaptability, and the damage rate in the process of grabbing fragile and fragile objects is reduced.

2. The invention has safe man-machine interaction and infinite freedom degree, and improves the motion capability of the mechanical arm; meanwhile, the soft pneumatic finger with transmembrane state touch perception (a soft touch perception method for representing touch information through soft deformation visual image information) is carried, so that not only can self-adaptive grabbing be realized, but also a transmembrane state touch sensor can be utilized to realize the perception of an object, and the soft pneumatic finger has the following perception functions: sensing whether the soft manipulator contacts an object; sensing whether the soft pneumatic finger successfully grabs the object or not, and monitoring the object grabbing stability in real time in the process of grabbing the object for placement; the texture information of the object can be obtained, the grasping force of the soft gripper which can stably grasp but cannot damage fragile objects is given by combining the priori knowledge, and the output grasping force is accurately controlled according to the sensing result of the contact force in the grasping process, so that the object is safely grasped.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings may be obtained according to these drawings for a person having ordinary skill in the art.

FIG. 1 is a schematic diagram of a software operating arm based on a cross-modal tactile sensor and a bubble driver according to the present invention;

FIG. 2 is a schematic diagram of a side view of a software operating arm based on a cross-modal tactile sensor and a bubble driver according to the present invention;

FIG. 3 is a schematic diagram of a system architecture of a transmembrane state tactile sensor in a soft manipulator arm based on a transmembrane state tactile sensor and a bubble driver according to the present invention;

FIG. 4 is a schematic diagram of a soft pneumatic finger structure of a soft manipulator based on a cross-modal tactile sensor and a bubble driver according to the present invention;

FIG. 5 is a schematic view of the planar structure of a soft pneumatic finger based on a soft manipulator arm of a cross-modal tactile sensor and bubble driver according to the present invention;

FIG. 6 is a schematic view of the structure of the inner cylindrical protrusions of the soft membrane of the soft manipulator based on the cross-modal touch sensor and the bubble driver according to the present invention;

FIG. 7 is a schematic diagram of a specific structure of a transmembrane state tactile sensor based on a transmembrane state tactile sensor and a soft operating arm of a bubble driver according to the present invention;

FIG. 8 is an enlarged schematic view of part A of FIG. 7 of a soft manipulator arm based on a cross-modal tactile sensor and bubble driver in accordance with the present invention;

FIG. 9 is a schematic diagram showing the operation of a trans-membrane tactile sensor based on a trans-modal tactile sensor and a soft operating arm of a bubble driver according to the present invention;

FIG. 10 is a schematic diagram of a workflow of a software operating arm based on a cross-modal tactile sensor and a bubble driver according to the present invention.

Reference numerals illustrate:

1. square acrylic fixing plate; 2. triangular acrylic support plates; 3. a bubble driver; 4. a spring; 5. a soft pneumatic finger; 6. a soft film; 7. a camera module; 8. a bubble driver air inlet; 9. a bubble driver air outlet; 10. pneumatic finger air inlet; 11. columnar projections inside the soft film; 12. a cable; 13. a mounting frame; 14. a camera; 15. a lamp bead; 16. acrylic sheet; 17. a transparent gel; 18. white circular markers.

Detailed Description

In order to make the explanation and the description of the technical solution and the implementation of the present invention clearer, several preferred embodiments for implementing the technical solution of the present invention are described below.

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, the same or similar reference numerals indicate the same or similar parts and features. The drawings merely schematically illustrate the concepts and principles of embodiments of the disclosure and do not necessarily illustrate the specific dimensions and proportions of the various embodiments of the disclosure. Specific details or structures of embodiments of the present disclosure may be shown in exaggerated form in particular drawings, various publications, patents and published patent specifications cited herein are incorporated herein by reference in their entirety and below are set forth in detail the embodiments of the present invention, which are obviously only a few embodiments of the present invention.

In the description of the present invention, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance unless explicitly specified or limited otherwise; the term "plurality" means two or more, unless specified or indicated otherwise; the terms "coupled," "secured," and the like are to be construed broadly, and may be used, for example, in a fixed or removable connection; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the description of the present specification, it should be understood that the terms "upper," "lower," "left," "right," and the like in the embodiments of the present application are described in terms of angles shown in the drawings, and should not be construed as limiting the embodiments of the present application. In the context of this document, it will also be understood that when an element is referred to as being "on" or "under" another element, it can be directly on the other element or be indirectly on the other element through intervening elements.

Example 1

Referring to fig. 1 to 10 of the specification, based on a soft operating arm of a cross-mode touch sensor and a bubble driver, the bubble driver 3 is arranged between triangular acrylic support plates 2, three bubble drivers 3 are equidistantly distributed at three vertex positions of the triangular acrylic support plates 2 around the center, springs 4 are arranged between the bubble drivers 3, two ends of each spring 4 are fixedly connected with one side of the triangular acrylic support plates 2, which is close to each other, the three springs 4 are distributed at the position of the edge center of the triangular acrylic support plates 2, the supporting function is achieved, the side wall of the topmost triangular acrylic support plate 2 is fixedly connected with the surface of a square acrylic fixed plate 1, three soft pneumatic fingers 5 are fixedly arranged on the bottom surface of the bottommost triangular acrylic support plate 2 through screws, the top of the soft pneumatic fingers 5 is provided with pneumatic finger air inlets 10, one sides of the soft pneumatic fingers 5, which are close to each other, are provided with soft films 6, one sides of the soft films 6, which are close to each other, are provided with a plurality of soft film inner column-shaped protrusions 11 which are arranged equidistantly, one sides of the soft films 6, which are far away from each other, are provided with camera modules 7, the camera modules 7 are integrated with lighting devices, images can be captured under the condition of no external light source, the top and the bottom of the bubble driver 3 are respectively provided with a bubble driver air outlet 9 and a bubble driver air inlet 8, the air pressure of the bubble driver 3 cannot be excessively high, otherwise, the bubble driver 3 is disabled, three soft pneumatic fingers 5 are distributed at the positions of three vertexes at the bottom of the bottommost triangle acrylic support plate 2 around the center equidistantly, the camera modules 7 are connected with a control system of a mechanical arm, the pneumatic finger air inlet 10 at the upper end of the soft pneumatic finger 5 is connected with an air pressure regulating device, and the air pressure regulating device controls the air pressure so as to avoid damaging the gripped object.

Example two

Based on the first embodiment, referring to fig. 1 to 10 of the specification, based on a soft operating arm of a cross-mode touch sensor and a bubble driver, the bubble driver 3 adopts a PE plastic film as a main material, the PE plastic film is divided into a plurality of telescopic small bubbles by using a triangular acrylic support plate 2 behind a through hole, three springs 4 are distributed at the center of a border line of the triangular acrylic support plate 2 to play a supporting role, axial expansion and contraction can be realized by inflating and deflating a single bubble driver 3, and a driving system formed by a plurality of bubble drivers 3 can be bent for a certain angle by providing different air inflow rates, so that the bending motion of an infinite degree of freedom of the mechanical arm is realized;

the soft film 6 utilizes the camera module 7 to collect deformation images of columnar protrusions 11 in the soft film, senses whether the soft pneumatic finger 5 contacts an object through conversion from a touch mode to a visual mode, senses whether the object is successfully grabbed and whether the object falls down or not, and can judge the grabbing force according to the number of deformation of the touch sensor after knowing the texture of the object, so that the air pressure of the input soft pneumatic finger is adjusted to realize different grabbing forces;

the camera module 7 is connected with the control system, when the object is grabbed, the soft film 6 on the fingertip of the soft pneumatic finger is extruded, so that the soft film 6 deforms to drive the columnar protrusion in the soft film to displace, at the moment, the camera module 7 shoots an image of the displaced columnar protrusion 11 in the soft film, then the image is transmitted to the control system, and the control system can acquire the contact force and the geometric information of the object by using an image processing method.

While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that modifications may be made to the described embodiments in various different ways without departing from the spirit and scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive of the scope of the invention, which is defined by the appended claims.

Claims

1. Soft operating arm based on stride modal touch sensor and bubble driver, including square ya keli fixed plate (1), triangle-shaped ya keli backup pad (2) and bubble driver (3), its characterized in that: the bubble drivers (3) are arranged between the triangular acrylic support plates (2), the three bubble drivers (3) are distributed at the positions of three vertexes of the triangular acrylic support plates (2) around the center at equal intervals, the air pressure of the bubble drivers (3) cannot be excessively high, otherwise, the bubble drivers (3) fail, and springs (4) are arranged between the bubble drivers (3);

the three springs (4) are distributed at the center of the side line of the triangular acrylic support plate (2) to play a supporting role, two ends of the springs (4) are fixedly connected with one side of the triangular acrylic support plate (2) which is close to each other, the side wall of the triangular acrylic support plate (2) at the top is fixedly connected with the surface of the square acrylic fixing plate (1), three soft pneumatic fingers (5) are fixedly arranged on the bottom surface of the triangular acrylic support plate (2) through screws, pneumatic finger air inlets (10) are formed in the tops of the soft pneumatic fingers (5), and transmembrane tactile sensors are arranged on one sides of the soft pneumatic fingers (5) which are close to each other;

transmembrane state touch sensor includes camera module (7), columnar protrusion (11), white circular marker (18) and software film (6), camera module (7) still include cable (12), mounting bracket (13), camera (14), lamp pearl (15), ya keli piece (16) and transparent gel (17), one side of keeping away from software film (6) at mounting bracket (13) is installed to cable (12), camera (14) are installed in the inner chamber of mounting bracket (13), and ya keli piece (16), lamp pearl (15) and transparent gel (17) all set up in the inner chamber of mounting bracket (13), inferior gram force piece (16) are located between lamp pearl (15) and transparent gel (17), white circular marker (18) set up in soft film inside columnar protrusion (11) keep away from on the one end of software film (6).

2. The cross-modal tactile sensor and bubble driver based software manipulator arm of claim 1 wherein: the top and the bottom of the bubble driver (3) are respectively provided with a bubble driver air outlet (9) and a bubble driver air inlet (8).

3. The cross-modal tactile sensor and bubble driver based software manipulator arm of claim 1 wherein: the three soft pneumatic fingers (5) are distributed at the positions of three vertexes at the bottom of the triangle acrylic support plate (2) at the bottommost part around the center at equal intervals.

4. The cross-modal tactile sensor and bubble driver based software manipulator arm of claim 1 wherein: the camera module (7) is connected with a control system of the mechanical arm, and a pneumatic finger air inlet (10) at the upper end of the soft pneumatic finger (5) is connected with an air pressure adjusting device, and the air pressure adjusting device controls the air pressure so as to avoid damaging a gripped object.

5. The cross-modal tactile sensor and bubble driver based software manipulator arm of claim 1 wherein: the three bubble drivers (3) are equidistantly distributed at the positions of three vertexes of the triangular acrylic support plate (2) around the center to play a driving role, the bubble drivers (3) adopt PE plastic films as main materials, the PE plastic films are divided into a plurality of telescopic small bubbles by the triangular acrylic support plate (2) after through holes, the three springs (4) are distributed at the positions of the edge centers of the triangular acrylic support plate (2) to play a supporting role, axial expansion and contraction can be realized by filling and discharging the single bubble driver (3), and a driving system formed by the multiple bubble drivers (3) can be bent by a certain angle by providing different air inlet rates, so that the bending motion of the mechanical arm with infinite degrees of freedom can be realized;

secondly, three soft pneumatic fingers (5) are equidistantly distributed around the center, the soft pneumatic finger fingertips are provided with the transmembrane tactile sensor system, the soft pneumatic fingers (5) are connected with an air pressure adjusting device through an air pressure inlet (10) of the pneumatic fingers, the air pressure adjusting device controls the air pressure so as to avoid damaging a gripped object, a soft film (6) collects deformation images of columnar protrusions (11) in the soft film through a camera module (7), whether the soft pneumatic fingers (5) contact the object or not is sensed through conversion from a touch mode to a visual mode, whether the object and the object fall down or not can be sensed, after knowing the texture of the object, the grabbing force can be judged according to the number of the shape variables of the touch sensor, and therefore the air pressure of the input soft pneumatic fingers is adjusted to achieve different grabbing forces;

the camera module (7) is integrated with the lighting device, an image can be captured under the condition of no external light source, a plurality of columnar protrusions (11) are arranged on the side face of the soft film (6), the camera module (7) is connected with the control system, when an object is captured, the soft film (6) on the fingertip of a soft pneumatic finger is extruded, the soft film (6) is deformed to drive the columnar protrusions (11) in the soft film to displace, at the moment, the camera module (7) shoots the image after the columnar protrusions (11) in the soft film displace, then the image is transmitted to the control system, and the control system can acquire the size of the contact force and the geometric information of the object by using an image processing method.