CN113427504A

CN113427504A - Be applied to soft finger of grabbing of space arm

Info

Publication number: CN113427504A
Application number: CN202110777552.3A
Authority: CN
Inventors: 田强; 徐培东; 王帅
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2021-07-09
Filing date: 2021-07-09
Publication date: 2021-09-24

Abstract

The invention discloses a soft-grip finger applied to a space manipulator, which comprises a pneumatic soft finger and a rigid support piece, wherein the pneumatic soft finger is arranged on the rigid support piece; the rigid supporting pieces are symmetrically fixed at the lower end parts of two sides of the pneumatic soft finger in the length direction, and the rigid supporting pieces on each side are hinged; the pneumatic soft finger is fixed at the tail end of the space mechanical arm. The invention improves the integral rigidity of the finger and can effectively inhibit the shaking of the finger.

Description

Be applied to soft finger of grabbing of space arm

Technical Field

The invention relates to the technical field of aerospace, in particular to a soft-gripping finger applied to a space manipulator.

Background

The structure of snatching that is applied to space manipulator at present is mostly the rigidity and snatchs the structure, can produce rigidity collision and vibration when snatching the object in the motion, has the danger of destroying the structure. The use of soft fingers made of soft materials can effectively avoid this problem and can accomplish many operations that cannot be achieved by conventional rigid fingers, such as: grab fragile or soft delicate objects, pass through a gap smaller than its normal size, and the like. The soft gripper is fully called as follows: the soft robot with the grabbing function is also fully applied in real life. When being applied to the field of space flight and aviation, the device can grab space debris and capture spy satellites. The soft gripper has the advantages of simple structure, direct drive, no need of gears, no influence of a backseat and friction, smooth action, no noise, easy miniaturization and the like. Compared with the traditional rigid gripper, the gripper has the advantages of high degree of freedom, strong self-adaptive capacity, light weight, simplicity in control, low cost, no influence of a backseat and friction and the like, and also faces challenges in aspects of control, structural design and the like.

In summary, compared with the traditional rigid gripper, the soft gripper can well fit the gripped object when gripping the object, and the continuous deformation of the soft gripper in the gripping process can realize flexible contact, so that the gripped object is prevented from being damaged due to rigid contact. Meanwhile, the soft hand grip also has the buffering and shock absorption capabilities which are not possessed by the traditional rigid hand grip. At present, the predecessors have abundant and detailed research on soft grippers for daily life, but still have the following problems, which prevent the application of soft grippers in space environment:

(1) the soft material used to make the soft grip has an ultra-high degree of freedom, which is uncontrollable for most of the degrees of freedom of the grip due to structural design defects. In the actual grabbing process, the uncontrollable swinging and shaking of the finger structure are often shown;

(2) the self rigidity of the soft gripper is limited, so that when the soft gripper is used for gripping objects with high speed and heavy weight, the gripped objects are not firm due to insufficient rigidity, and the gripped objects are easy to separate from the gripper;

(3) the soft gripper is accompanied with the change of the self rigidity of the structure in the deformation process, the attachment degree between the gripper and the gripped object is not high, so that the gripping efficiency and the gripping effect of the soft gripper are reduced;

(4) the size of the soft gripper can directly influence the size range of the object which can be gripped by the soft gripper, and the effect of one-claw multi-use is difficult to realize.

Disclosure of Invention

In view of this, the invention provides a soft-grip finger applied to a space manipulator, which improves the overall rigidity of the finger and can effectively inhibit the finger from shaking.

The technical scheme adopted by the invention is as follows:

a soft hand grip finger applied to a space manipulator comprises a pneumatic soft finger and a rigid support piece;

the rigid supporting pieces are symmetrically fixed at the lower end parts of two sides of the pneumatic soft finger in the length direction, and the rigid supporting pieces on each side are hinged; the pneumatic soft finger is fixed at the tail end of the space mechanical arm.

Further, the pneumatic soft finger comprises an air cavity and a packaging layer; the air cavities are arranged at equal intervals along the same direction, and the packaging layer is fixed at the bottom of the air cavities to seal the air cavities.

Furthermore, the packaging layer is provided with mounting holes along the width direction of the fingers, and the rigid supporting pieces on the two sides are connected together through the mounting holes.

Furthermore, the mounting hole is arranged at the position of the packaging layer corresponding to the front end of the air cavity, and the tail end of the finger is in front.

Further, the rigid support is a sheet-like structure.

Further, the rigid supporting piece is fixed in two adjacent mounting holes.

Further, the rigid supporting piece covers more than three mounting holes and is rotatably connected with the adjacent rigid supporting piece through the mounting hole on the outermost side.

Further, the air cavity is rectangular, and the inner cavity is rectangular.

Furthermore, the air cavity is rectangular, and the inner cavity is of a three-dimensional structure with two inwards-recessed sides.

Furthermore, the pneumatic soft finger adopts silica gel.

Has the advantages that:

1. the rigid support piece restrains the freedom degrees of two sides of the finger, and can effectively inhibit the finger from shaking; the rigid support piece effectively improves the overall rigidity of the fingers, and the soft hand grip manufactured based on the fingers can stably grip objects with high speed and large inertia in an aerospace weightless environment.

2. The invention adopts the rigid supporting pieces with different lengths to cover the mounting holes with different numbers, can realize the control of the deformation size range of the fingers, and can grab objects with different sizes in an adaptive manner, thereby realizing the effect of one claw with multiple purposes.

3. The internal cavity of the air cavity adopts a three-dimensional structure with two inwards concave sides, so that the lateral expansion of the air cavity can be inhibited under the same air pressure, the axial extension is easy, and the bending curvature of fingers is large; at the same time, the rectangular configuration of the profile further inhibits lateral expansion thereof.

Drawings

Fig. 1 is a front view of the overall structure of the present invention.

Fig. 2 is a top view of the overall structure of the present invention.

Fig. 3 is a left side view of the overall structure of the present invention.

Fig. 4 is a three-dimensional view of the overall structure of the present invention.

FIG. 5 is a schematic view of the rigid support member connection of the present invention.

Fig. 6 is a partial cutaway perspective view of a finger of the soft grip of the present invention.

Fig. 7 is a perspective view of an air cavity with an inner cavity with two sides recessed inwards.

Fig. 8 is a top view of an air cavity with an inner cavity with two sides recessed inwards.

The device comprises an air cavity 1, a packaging layer 2, a rigid support 3, a screw rod 4 and a nut 5.

Detailed Description

The invention is described in detail below by way of example with reference to the accompanying drawings.

The invention provides a soft-grip finger applied to a space manipulator, which comprises a pneumatic soft finger and a rigid support part 3. Fixed at the end of the space manipulator by a rigid support 3.

As shown in fig. 1-5, the pneumatic soft finger is based on an inflatable grid structure (pneuenets), and includes an air cavity 1 and a packaging layer 2, wherein a plurality of air cavities 1 are equidistantly arranged along the same direction, and the packaging layer 2 is fixed at the bottom of the air cavity 1 to seal the air cavity 1. The pneumatic soft finger is made of silica gel.

As shown in fig. 6, the packaging layer 2 is provided with mounting holes along the width direction of the fingers, and the rigid supports 3 on both sides are connected together through the mounting holes. The mounting hole is arranged at the position of the packaging layer 2 corresponding to the front end of the air cavity 1, and the tail end of the finger is in front.

The rigid support 3 is a plate-shaped structure, and in this embodiment, a straight plate-shaped rigid support is adopted and is made of 304 steel. The rigid support 3 is provided with a through hole which fits the mounting hole. The through holes at the two ends of the rigid support parts 3 are waist-shaped holes, and allowance is provided for the connection of the two adjacent rigid support parts 3.

A plurality of rigid support pieces 3 are symmetrically fixed on the packaging layers 2 on two sides of the pneumatic soft finger in the length direction, screw rods 4 are arranged in the mounting holes, the rigid support pieces 3 on the two sides are connected together through the screw rods 4, and the rigid support pieces 3 on each side are hinged. The adjacent rigid supporting pieces 3 are sleeved on the same screw rod 4 and fixed through nuts 5.

The rigid support members 3 with different lengths are adopted, the rigid support members 3 can be fixed in two adjacent mounting holes and can also cover more than three mounting holes, and the mounting holes on the outermost side are rotatably connected with the adjacent rigid support members 3, so that the deformation size of the fingers is changed, and objects with different sizes can be picked in an adaptive manner.

In this embodiment, the pneumatic soft finger includes 12 air cavities 1, the air cavities 1 are rectangular, the internal cavity is rectangular, 14 mounting holes are arranged on the packaging layer 2 along the length direction of the pneumatic soft finger, wherein, 12 mounting holes correspond to the air cavities 1, and two mounting holes at the rear end of the finger are used for realizing the fixed connection between the rigid support member 3 and the tail end of the mechanical arm in the external space.

As shown in fig. 7 and 8, the cavity inside the air cavity 1 may also be a three-dimensional structure with two sides recessed inwards, and the shape is still rectangular.

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A soft-gripping finger applied to a space manipulator is characterized by comprising a pneumatic soft finger and a rigid support piece;

2. The soft-grip hand finger for a space manipulator according to claim 1, wherein the pneumatic soft finger comprises an air cavity and an encapsulating layer; the air cavities are arranged at equal intervals along the same direction, and the packaging layer is fixed at the bottom of the air cavities to seal the air cavities.

3. A soft-grip finger for a space manipulator as claimed in claim 2, wherein the packaging layer has mounting holes along the width of the finger, and the rigid supports at both sides are connected together through the mounting holes.

4. A soft-grip hand finger for a space manipulator according to claim 3, wherein the mounting hole is formed at the position of the encapsulation layer corresponding to the front end of the air cavity, and the tail end of the finger is the front end.

5. A soft-grip finger for a space manipulator as claimed in claim 3, wherein the rigid support is a sheet-like structure.

6. A soft hand grip finger for a space manipulator according to claim 5 wherein the rigid support member is secured in two adjacent mounting holes.

7. A soft hand grip finger for a space manipulator according to claim 5 wherein the rigid support member covers more than three mounting holes and is pivotally connected to the adjacent rigid support member through the outermost mounting hole.

8. A soft-grip hand finger for use with a space manipulator according to any of claims 2-7, wherein the air cavity is rectangular and the internal cavity is rectangular.

9. A soft-gripping finger for a space manipulator according to any one of claims 2 to 7, wherein the air cavity is rectangular and the internal cavity is a three-dimensional structure with two inwardly-recessed sides.

10. A soft-gripping finger for a space manipulator according to any one of claims 1 to 7, wherein the pneumatic soft finger is made of silicone.