CN113183174B

CN113183174B - Soft robot gripper based on magnetic ball reinforced elastomer

Info

Publication number: CN113183174B
Application number: CN202110573857.2A
Authority: CN
Inventors: 胡福文; 程景丽
Original assignee: North China University of Technology
Current assignee: North China University of Technology
Priority date: 2021-05-25
Filing date: 2021-05-25
Publication date: 2022-10-11
Anticipated expiration: 2041-05-25
Also published as: CN113183174A

Abstract

The invention relates to a soft robot gripper based on a magnetic ball reinforced elastomer, which comprises a base and gripping fingers, wherein the gripping fingers are arranged on the base; the base is annular, the outer side of the base is provided with a connecting arm for mounting a clamping finger, the clamping finger is fixed below the connecting arm and comprises an inner side serving as a clamping surface and a corresponding outer side, the outer side is fixed with a plurality of magnetic balls, and a boss is arranged between each magnetic ball; the clamping finger is made of strip-shaped soft materials, a first line hole is formed in the clamping finger, a plurality of first line grooves are formed in the inner side of the clamping finger, second line grooves are formed in the connecting arm, and a plurality of second line holes are formed in the inner side wall of the base. According to the technical scheme, the self-bending composite structure is formed by utilizing the elastic coupling of the magnetic force field between the magnetic balls and the silica gel, and the self-bending composite structure is controlled in a reciprocating mode by the servo motor driving tether, so that the problems that the response time is slow and the form change is limited are solved, the elastic performance of the elastomer is enhanced, and the stability and the practicability of clamping are also guaranteed due to the large clamping range.

Description

Soft robot gripper based on magnetic ball reinforced elastomer

Technical Field

The invention relates to the technical field of robot tail end clampers, in particular to a soft robot clamper based on a magnetic ball reinforced elastomer.

Background

The gripper is one of the tail end actuating mechanisms of the robot, can clamp and release a target grabbing object through force constraint or shape constraint, and is widely applied to various industrial automatic production. The soft gripper is made of a soft elastic material with low rigidity, can grip objects with different shapes or fragile objects in a certain range in a self-adaptive manner, and gradually becomes one of important tool accessories of the intelligent robot.

The existing clamp holders have certain problems, like a manipulator which is completely imitated by a human hand and disclosed by the patent number CN201710392167.0, the whole hand has 14 bending degrees of freedom, 12 touch sensors and 4 bending sensors, and can be used for capturing and sensing in real time. The whole body is manufactured into the 5-finger humanoid manipulator by adopting the 3D printing technology through one-step forming, the manipulator provided by the invention has high imitative property, and has the characteristics of simple structure, small volume and high softness, but the manipulator has a limited range for clamping objects, and the finger material belongs to plastics, has high hardness and is easy to damage the outer surfaces of the objects. 5 fingers utilize the rope drive simultaneously, and motor load is too big, greatly reduces finger life.

Similarly, like a pneumatic soft gripper disclosed in patent No. CN201920037409.9, fingers are formed by pouring silicone rubber at one time, kevlar wires and glass fibers are embedded in the silicone rubber, and the fragile objects are gripped without damage by using the compressibility of gas and the elasticity of the soft gripper jaws. The soft clamp holder is driven by a motor, a swing arm is driven by the rotation of a screw rod, fingers are driven by air pressure to bend and clamp, the whole process involves too many parts, the assembly is complex, and the self weight of the clamp holder is too large.

For another example, CN202010934730.4 discloses a soft body gripper, which is mainly installed on an external lifting mechanism and comprises a plurality of gripper assemblies and a control part. The contact of the object is sensed by the air bag with the pressure intensity set on the finger, and then the clamping procedures are used for controlling the clamping jaws to move oppositely at the same time, so that the clamping action is completed. The clamping device can well determine that a preset workpiece enters the clamping range of the clamping jaws and finishes clamping the preset workpiece by the clamping jaws, but the clamping range of the clamping device is limited, the response time for finishing clamping is too long, and long-time friction of particles in the air bag can cause damage to the air bag, so that the service life is shortened.

The inventor has studied the existing clamper and made an effort to improve the existing clamper by utilizing the relationship between the magnetic balls and the elastic body, by the elastic coupling of the magnetic force field between the magnetic balls and the silicon gel itself, and by utilizing the characteristics of the motor drive; a soft body clamp holder based on a magnetic ball reinforced elastic body is designed to solve the problems in the prior art.

Disclosure of Invention

The invention provides the soft robot gripper prepared by the magnetic ball-silica gel coupling elastomer structure, aiming at solving the problems of limitation in response time and form change, complex assembly and the like of the existing soft gripper, effectively enhancing the elastic property of the elastomer, ensuring the stability and the practicability of the gripper while having a large gripping range.

The specific technical scheme of the invention is as follows:

a soft robot gripper based on a magnetic ball reinforced elastomer comprises a base and gripping fingers; the base is annular, at least 3 connecting arms for installing clamping fingers are further arranged on one circle of the outer side of the base, the clamping fingers are fixed below the connecting arms and comprise inner sides serving as clamping surfaces and corresponding outer sides, a plurality of magnetic balls are fixed on the outer sides, and a boss is arranged between each magnetic ball; the clamping finger is of a strip-shaped structure made of soft materials, a first line hole which is communicated with the clamping finger is formed in the other end of the clamping finger from one end of the clamping finger, a plurality of first line grooves are formed in the inner side of the clamping finger, second line grooves are formed in the connecting arm, and a plurality of second line holes are formed in the inner side wall of the base.

Furtherly, still include the stationary vane, the stationary vane set up in the top middle part position of annular base, the stationary vane is the cross, the tip of four of cross stationary vane all is equipped with the third line hole.

And one end of the nylon wire is wound and fixed through the third wire hole, penetrates through the second wire hole and the second wire groove respectively, penetrates into the clamping finger from one end of the first wire hole, and penetrates through the first wire grooves one by one to be fixed at the fingertip position from the lower end of the first wire hole.

And furthermore, a base station is arranged on the inner side of the base, a steering engine is fixed on the base station, and the steering engine is connected with the nylon rope.

And furthermore, a plurality of bracket holes are formed in the inner side wall of the annular base, and the base is fixed on the mechanical arm through the bracket holes.

Still further, the base outside round is equipped with at least 3 sensor draw-in grooves that are used for installing hall sensor, the sensor draw-in groove with the mutual crisscross interval setting of linking arm is in the base outside, hall sensor with the sensor draw-in groove adopts the mounting means of X, Y, Z quadrature configuration.

Still further, the first wire grooves are the same in number as the magnetic balls, and each first wire groove is arranged at the inner side position below the magnetic ball corresponding to each magnetic ball.

Preferably, the lower end of each connecting arm is provided with a finger clamping groove, the top end of each clamping finger is provided with a connecting boss, and the connecting boss at the top end of each clamping finger is matched with the boss through the finger clamping groove.

Preferably, the integrated structure of the clamping fingers is formed by integrally pouring magnetic balls and silica gel, the magnetic balls are prepared from neodymium iron boron materials and have magnetic buckyballs, and the clamping fingers are prepared from No. 903 RTV-2 molding silicone rubber.

Preferably, each magnetic ball on the clamping finger is arranged at equal intervals, and two corners with an angle of 45 degrees are symmetrically cut at two sides of the lower end fingertip of the clamping finger.

The invention has the beneficial effects that:

1. the clamp holder structurally forms a self-bending composite structure through the elastic coupling of a magnetic force field between magnetic balls and silica gel, and the self-bending composite structure is regulated and controlled in a reciprocating mode through a motor-driven tether; the clamping device has the advantages of simple and reliable structure, relatively low manufacturing cost, large clamping range and more stable clamping effect, and solves the problems of slow response time and limitation on form change.

2. The magnetic ball-silica gel coupling elastomer structure is prepared by integrated pouring molding, so that the assembly process is simplified, in addition, the magnetic ball strengthens the elastomer, the grabbing action can be quickly and effectively finished, and the clamping efficiency is improved; meanwhile, the durability of the clamp is high, the joint part of a common manipulator clamping structure is easy to damage, the deformation capacity of the elastomer is enhanced by the magnetic ball, and the formed soft clamp has strong robustness, can be used for a longer time and has better clamping effect under the same condition.

3. The state of the fingers clamping the object can be fed back in real time through the Hall sensor; therefore, the soft clamp holder based on the magnetic ball reinforced elastomer has the advantages of intelligence, simplicity, easy operation, high clamping efficiency and the like, has important application value in a plurality of fields such as the industrial field, the bionic scientific field, the medical scientific field and the like, has a simple structure, can be produced in large batch, and has wide application range.

Drawings

FIG. 1 is an exploded view of the overall construction of the holder of the present invention;

FIG. 2 is a view showing the structure of a fixed wing of the holder of the present invention;

FIG. 3 is a schematic view of the outer side of the gripping fingers of the gripper of the present invention;

FIG. 4 is a schematic view of the inside structure of the gripping fingers of the gripper of the present invention;

FIG. 5 is a schematic view of the base structure of the holder of the present invention;

FIG. 6 is a top view of the base structure of the holder of the present invention;

FIG. 7 is a bottom view of the base structure of the holder of the present invention.

Description of reference numerals: 1. a fixed wing; 2. a base; 3. a sensor card slot; 4. clamping fingers; 5. a boss; 6. a magnetic ball; 7. a first wire slot; 8. a connecting arm; 9. a steering engine; 10. connecting the bosses; 11. a finger base; 12. a first wire hole; 13. a second wire hole; 14. a bracket hole; 15. a base station; 16. a second wire slot; 17. a finger card slot; 18. a third wire hole; 19. and (4) screws.

Detailed Description

The soft robot gripper based on the magnetic ball reinforced elastomer of the present invention is further described in detail with reference to the drawings and the following embodiments.

Examples

Example one

Referring to fig. 1, the present example discloses a gripper for a soft robot based on a magnetic ball reinforced elastomer, which has the advantages of simple and reliable structure, relatively low manufacturing cost, large gripping range, fast gripping response time, etc., and specifically comprises a fixed wing 1, a base 2, a sensor slot 3 and a gripping finger 4; the base 2 is annular, the fixed wing 1 is arranged at the middle position above the annular base 2, at least 3 connecting arms 8 for mounting clamping fingers 4 are further arranged on one circle of the outer side of the base 2, the clamping fingers 4 are fixed below the connecting arms 8, each clamping finger 4 comprises an inner side 42 serving as a clamping surface and a corresponding outer side 41, a plurality of magnetic balls 6 are fixed on the outer sides 41, and a boss 5 is arranged between each magnetic ball 6; the clamping finger 4 is a strip-shaped structure made of soft materials, the clamping finger 4 is provided with a first line hole 12 which is communicated from one end to the other end, the inner side 42 of the clamping finger 4 is provided with a plurality of first line grooves 7, the connecting arm 8 is provided with a second line groove 16, the inner side of the base 1 is provided with a base platform 15, a steering engine 9 is fixed on the base platform 15, the steering engine 9 is connected with a nylon rope, the steering engine 9 is fixed on the base platform 15 of the base through a screw 19, and the inner side wall of the base 2 is provided with a plurality of second line holes 13. The finger clamping device further comprises a nylon wire for contracting fingers, wherein one end of the nylon wire is wound and fixed through the third wire hole 18, penetrates through the second wire hole 13 and the second wire groove 16 respectively, penetrates into the clamping finger 4 from one end of the first wire hole 12, penetrates through each first wire groove 7 in a one-to-one staggered mode, and is fixed at the fingertip position through a pressing sheet from the lower end of the first wire hole 12.

As further shown in fig. 2, the fixed wing 1 is cross-shaped, and the four end portions of the cross-shaped fixed wing are provided with third wire holes 18; the lower end of each connecting arm 8 is provided with a finger clamping groove 17, the top end of each clamping finger 4 is provided with a connecting boss 10, and the connecting bosses 10 at the top ends of the clamping fingers 4 are matched with the bosses through the finger clamping grooves 17. The clamping fingers of the clamp holder are preferably 3, the clamping fingers 4 are manufactured by adopting magnetic ball-silica gel integrated pouring forming, the fingers are matched with a finger clamping groove 17 of a connecting arm 8 of the base 2 through a connecting boss 10, the wire pulling assembly is used for achieving the state that the fingers are bent and extended, the number of the first wire grooves 7 is the same as that of the magnetic balls, and each first wire groove 7 corresponds to each magnetic ball 6 and is arranged at the inner side position below the magnetic ball.

The power supply is switched on, the steering engine 9 rotates to drive the nylon wire, the nylon wire is wound along the rotation direction of the steering engine 9, the tension of the wire and the finger tip of a finger and the contact surface force of the wire and silica gel on the inner side of the finger act on the nylon wire, the boss 5 between the magnetic ball 6 and the magnetic ball are driven to be twisted to generate displacement, and the finger 4 achieves the effect of bending and clamping;

furthermore, a second wire slot 16 on the connecting arm 8 and a second wire hole 13 on the base 2 are used for fixing the radial position of the nylon wire, so that the phenomenon that the finger is twisted due to the fact that the tensile direction of the nylon wire and the axial direction of the finger 4 are not on the same horizontal line when the steering engine 9 rotates is prevented.

The embodiment utilizes the magnetic ball to strengthen the elastic body, and the provided soft gripper can quickly and effectively complete the gripping action, thereby improving the gripping efficiency. Meanwhile, the soft clamp has high durability, the joint part of the common manipulator clamping structure is easy to damage, the soft clamp has strong robustness, can be used for a longer time, and has better clamping effect under the same condition. And the state of the finger clamping object can be fed back in real time through the Hall sensor. Therefore, the soft clamp holder based on the magnetic ball reinforced elastomer has the advantages of intelligence, simplicity, easy operation, high clamping efficiency and the like, and has important application value in the industrial field, the bionic scientific field and the medical scientific field.

Example two

The preparation method of the gripper fingers is further limited on the basis of the embodiment 1 in the embodiment 2, and the fingers are prepared by magnetic ball-silica gel integrated pouring molding; utilize 3D printing technique, print finger mould, put into the circular slot that has set for in the mould with magnetic ball 6, fill whole mould with proportioned silica gel, stir with the plastic stick, make magnetic ball and silica gel fully fuse, twist into the long stick with the solder wire again, insert in the silica gel, cover the mould upper cover, treat its solidification shaping after, take out the software finger 4 of preparation, extract the long stick, leave first wire hole 12, the nylon wire of being convenient for threads.

Describing with reference to the clamping fingers shown in fig. 3 and 4, two sides of the lower end fingertip of the clamping finger are symmetrically cut to form two side angles of 45 degrees, one side of each magnetic ball 6 is embedded into a finger base 11, the thickness of each finger base 11 is 2mm, the distance between every two magnetic balls 6 is 3mm, and the bosses 5 are correspondingly arranged among the magnetic balls 6; the other side of the finger base 11 and the equidistant wire casing I7 which is arranged under the boss 5 are convenient for threading and leading of the wire pulling component, and the finger 4 is bent under the on-line tension, and simultaneously, the load of the steering engine 9 is also reduced, so that the clamp holder achieves the effect of simulating the clamping of the finger.

Meanwhile, as a preferred scheme, the integral structure of the clamping fingers 4 is formed by integrally pouring magnetic balls and silica gel, the magnetic balls 6 are magnetic buckyballs prepared from neodymium iron boron, the clamping fingers 4 are prepared from mold-making silica gel with the material No. 903 RTV-2, a self-bending composite structure is formed by the elastic coupling of a magnetic force field between the magnetic balls and the silica gel, and the self-bending composite structure is controlled by a tether driven by a servo motor in a reciprocating mode; the structure for holding the finger is preferably 5 magnetic balls and 4 bosses, the bosses 5 are used for separating the magnetic balls 6, and the size of the bosses 5 is 2.5 × 3 × 12, so that the function of buffering and protecting the finger 4 can be achieved.

Further, it should be described with reference to fig. 3 and 4 that two sides of the clamping finger 4 adopt different structural designs, one side of the clamping finger is provided with the magnetic balls 6 and the bosses 5 which are arranged at equal intervals, and the other side of the clamping finger is a silica gel plane, that is, one side of the clamping finger is a driving layer, and the other side of the clamping finger is a limiting layer, so that the clamping finger 4 can achieve the clamping effect under the condition of low energy consumption. The fingers 4 prepared by coupling the magnetic balls and the silica gel are used for reinforcing the elastic body by the magnetic balls 6, and the fingers slightly bent towards one side of the magnetic balls increase the clamping range of the clamp holder.

EXAMPLE III

Referring to fig. 5 to 7, in embodiment 3, the base is further limited on the basis of embodiment 1, at least 3 sensor slots 3 for installing hall sensors are arranged in a circle outside the base 2, the sensor slots 3 and the connecting arms 8 are arranged outside the base 2 at intervals in a staggered manner, a finger slot 17 is arranged at the lower end of each connecting arm 8, a connecting boss 10 is arranged at the top end of each clamping finger 4, the connecting boss 10 at the top end of each clamping finger 4 is matched with the boss through the finger slot 17, a plurality of support holes 14 are formed in the inner side wall of the annular base 2, and the base 1 is fixed on a mechanical arm through the support holes 14.

The Hall sensor and the sensor clamping groove 3 adopt an X, Y and Z orthogonal configuration installation mode, and through observation in a serial port monitor and a serial port plotter of Arduino software, when a steering engine 9 rotates and pulls a nylon wire to enable fingers to bend and clamp objects with different sizes, the vibration frequency of a oscillogram and data can immediately reflect whether the objects and the size range of the objects are grabbed or not; the Hall sensor senses the change of the magnetic field when the finger 4 is bent, so that the state of the finger clamping an object is fed back in real time.

The invention utilizes the advantages of the magnetic ball reinforced elastomer and has the advantages of simple and reliable structure, relatively low manufacturing cost and large clamping range. Meanwhile, the magnetic ball-silica gel coupling elastomer structure is prepared by integrated pouring molding, so that the assembly process is simplified, in addition, the magnetic ball strengthens the elastomer, the grabbing action can be quickly and effectively finished, and the clamping efficiency is improved; meanwhile, the durability of the manipulator is high, joint parts of a common manipulator clamping structure are easy to damage, the deformation capacity of the elastomer is enhanced by the magnetic balls, and the formed soft clamp has strong robustness and can be used for a longer time, and the clamping effect is better under the same condition.

The state of the fingers clamping the object can be fed back in real time through the Hall sensor; therefore, the soft clamp holder based on the magnetic ball reinforced elastomer has the advantages of intelligence, simplicity, easy operation, high clamping efficiency and the like, has important application value in a plurality of fields such as the industrial field, the bionic scientific field, the medical scientific field and the like, has a simple structure, can be produced in large batch, and has wide application range.

The above-mentioned embodiments are merely descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and all other embodiments that can be obtained by those skilled in the art without creative efforts based on the embodiments of the present invention belong to the protection scope of the present invention, and various changes and modifications of the technical solution of the present invention by those skilled in the art without departing from the concept of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. The utility model provides a soft robot holder based on magnetic ball reinforcing elastomer which characterized in that: comprises a base (2), clamping fingers (4) and a fixed wing (1);

the base (2) is annular, at least 3 connecting arms (8) for mounting clamping fingers (4) are further arranged on one circle of the outer side of the base (2), the clamping fingers (4) are fixed below the connecting arms (8), each clamping finger (4) comprises an inner side (42) serving as a clamping surface and a corresponding outer side (41), a plurality of magnetic balls (6) are fixed on the outer sides (41), and a boss (5) is arranged between each magnetic ball (6);

the clamping finger (4) is of a strip-shaped structure made of soft materials, a through first wire hole (12) is formed in the clamping finger (4) from one end to the other end, a plurality of first wire grooves (7) are formed in the inner side (42) of the clamping finger (4), a second wire groove (16) is formed in the connecting arm (8), a plurality of second wire holes (13) are formed in the inner side wall of the base (2), and the clamping finger (4) is integrally cast and molded by magnetic balls and silica gel in an integral structure;

the fixed wings (1) are arranged in the middle position above the base (2) and are cross-shaped, and the four end parts of the fixed wings are provided with third wire holes (18);

base (2) outside round is equipped with at least 3 sensor draw-in grooves (3) that are used for installing hall sensor, sensor draw-in groove (3) with the interval that linking arm (8) are crisscross each other sets up base (2) outside, hall sensor with sensor draw-in groove (3) adopt the mounting means of X, Y, Z quadrature configuration.

2. The holder of claim 1, wherein: the finger clamping device is characterized by further comprising a nylon wire, wherein one end of the nylon wire is wound and fixed through the third wire hole (18), penetrates through the second wire hole (13) and the second wire groove (16) respectively, penetrates into the clamping finger (4) from one end of the first wire hole (12), and penetrates through the first wire grooves (7) one by one in a staggered mode to be fixed at the fingertip position from the lower end of the first wire hole (12).

3. The holder according to claim 2, characterized in that: the inner side of the base (2) is provided with a base platform (15), a steering engine (9) is fixed on the base platform (15), and the steering engine (9) is connected with a nylon rope.

4. The holder according to claim 1, wherein: a plurality of support holes (14) are formed in the inner side wall of the base (2), and the base (2) is fixed on the mechanical arm through the support holes (14).

5. The holder of claim 1, wherein: the number of the first wire grooves (7) is the same as that of the magnetic balls, and each first wire groove (7) is arranged at the inner side position below the magnetic ball corresponding to each magnetic ball (6).

6. The holder according to claim 1, wherein: every linking arm (8) lower extreme is equipped with finger draw-in groove (17), the top of centre gripping finger (4) is equipped with connects boss (10), the connection boss (10) on centre gripping finger (4) top pass through finger draw-in groove (17) with the boss cooperation.

7. The holder of claim 1, wherein: magnetic ball (6) are by the preparation of neodymium iron boron material and have magnetic buckyball, centre gripping finger (4) are by the preparation of material for No. 903 RTV-2 moulding silicon rubber.

8. The holder of claim 1, wherein: every magnetic ball (6) on centre gripping finger (4) equidistant setting, centre gripping finger's lower extreme fingertip bilateral symmetry intercepting two corners at 45 jiaos.