Soft dexterous hand structure with tactile perception function

Abstract

The utility model belongs to the technical field of intelligent robots, and particularly discloses a soft dexterous hand structure with a touch sensing function. The structure comprises a palm and soft fingers connected with the palm. The soft finger comprises a flexible finger body, a flexible sensor layer and an inextensible layer are arranged on the side, close to the finger pulp, of the interior of the flexible finger body from inside to outside, a partition is arranged in the middle of the flexible finger body, the hollow interior of the flexible finger body is divided into an upper air cavity and a lower air cavity, and the two air cavities are not communicated. The upper air cavity and the lower air cavity are respectively connected with an air source; when the upper air cavity is inflated, the upper knuckles are bent and deformed, and the upper knuckles are matched with other fingers to realize the pinching action of fingertips; the lower air cavity is inflated, the lower knuckles are bent and deformed, and the clamping action of the finger root knuckles can be achieved; meanwhile, the upper air cavity and the lower air cavity are inflated, the whole finger is bent and deformed, and the enveloping type grabbing action of the whole hand can be achieved by being matched with the other fingers. The dexterous hand structure has multiple bending modes and can be suitable for different tasks.

Description

Technical Field

[0001] The utility model relates to the technical field of intelligent robots, in particular to a soft dexterous hand structure with a tactile perception function. Background Art

[0002] As robots continue to improve their intelligence and operational capabilities, they are becoming increasingly integrated into people's daily lives, particularly in areas like nursing and healthcare. The safety of human-robot interactions has drawn widespread attention, requiring intelligent robots to be more compliant, flexible, and safe during these interactions. Traditional dexterous robotic hands are not only complex in structure and lack flexibility, but also suffer from poor perception during human-robot interactions. Soft robotic hands made of flexible materials offer these qualities, along with flexibility and safety, that traditional dexterous robotic hands lack.

[0003] Patent application number 201810725771.5 discloses a three-fingered soft robot with variable stiffness. Each soft finger is driven by gas to produce bending and variable stiffness. From top to bottom, it is mainly composed of a driving layer, an inextensible layer, and a variable stiffness layer. The driving layer is composed of multiple interconnected airbags, which can produce bending under positive pressure. However, the soft fingers of this robot can only bend as a whole to complete the envelope grasping action of the entire hand. The bending mode is limited, making it difficult to adapt to different working scenarios. Utility Model Content

[0004] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a soft dexterous hand structure with tactile perception function.

[0005] The utility model solves the technical problem by adopting the following technical solutions:

[0006] A soft dexterous hand structure with tactile perception function includes a palm and soft fingers connected to the palm; the soft fingers include a flexible finger body, and a flexible sensor layer and a non-extensible layer are provided from the inside to the outside on the side of the flexible finger body close to the fingertip; a partition is provided in the middle of the flexible finger body, which divides the hollow interior of the flexible finger body into an upper air cavity and a lower air cavity, and the two air cavities are not connected. The upper air cavity and the lower air cavity are respectively connected to an air source, and the finger bending is achieved by inflating and deflating the air cavity.

[0007] Furthermore, the palm includes a palm base, multiple finger joints, a thumb joint, a connecting piece, a thumb joint servo and a multiple finger joint servo; the thumb joint servo is located on one side of the palm base, the lower end of the thumb joint is rotatably connected to one side of the palm base, the upper end of the thumb joint is connected to the output end of the thumb joint servo, and a soft finger is connected to the thumb joint; the multiple finger joint servo is located on the other side of the palm base, the output end of the multiple finger joint servo is connected to one side of the multiple finger joint, the other side of the multiple finger joint is rotatably connected to the upper end of the connecting piece, the lower end of the connecting piece is inserted into the upper end of the thumb joint and does not affect the rotation of the thumb joint; multiple soft fingers are connected to the multiple finger joints.

[0008] Furthermore, the multiple finger joints are two finger joints, three finger joints or four finger joints.

[0009] Furthermore, a plurality of reinforcing ribs arranged along the width direction of the finger are respectively provided in the upper air cavity and the lower air cavity, and a plurality of bosses are arrayed on the dorsal side of the flexible finger body.

[0010] Furthermore, the flexible sensor layer includes a plurality of flexible sensors arranged in an array, and the flexible sensors are capacitive flexible sensors.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] 1. The soft fingers imitate humanoid fingers, simplifying the three-joint fingers of the human body into two-joint fingers. While reducing the difficulty of control, they can realize three bending modes: upper joint, lower joint and whole hand. Then, they can complete pinching of fingertips, clamping of base joints and envelope grasping of the whole hand, etc., which is suitable for different tasks.

[0013] 2. The flexible sensor can detect contact pressure, giving the fingers tactile perception and improving the perception ability of the dexterous hand structure.

[0014] 3. The soft fingers are pneumatically driven to achieve bending and deformation, making operation easier. The fingers are made of flexible materials, which are safe and can interact with fragile objects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the overall structure;

[0016] Figure 2 Schematic diagram of the structure of the palm;

[0017] Figure 3 This is an exploded view of the soft finger;

[0018] Figure 4 This is a diagram of the internal structure of the flexible finger body;

[0019] Figure 5Schematic diagram of the bending mode of the soft finger;

[0020] In the figure, 1-palm; 2-soft fingers; 11-palm base; 12-multi-finger joints; 13-thumb joints; 14-connecting parts; 15-thumb joint servo; 16-multi-finger joint servo; 17-palm front shell; 18-palm back shell; 21-flexible finger body; 22-upper air cavity; 23-lower air cavity; 24-reinforcement ribs; 25-partition; 26-flexible sensor layer; 27-non-extensible layer; 28-boss. DETAILED DESCRIPTION

[0021] Specific embodiments are given below in conjunction with the accompanying drawings. The specific embodiments are only used to introduce the technical solutions of the present utility model in detail and are not intended to limit the scope of protection of the present application.

[0022] The utility model provides a soft dexterous hand structure with a tactile perception function, comprising a palm 1 and a plurality of soft fingers 2 connected with the palm 1 .

[0023] The palm 1 includes a palm base 11, multiple finger joints 12, a thumb joint 13, a connecting piece 14, a thumb joint servo 15, a multiple finger joint servo 16, a palm front shell 17 and a palm back shell 18; wherein, the thumb joint servo 15 is installed on one side of the palm base 11, the lower end of the thumb joint 13 is rotatably connected to the connecting column on one side of the palm base 11, the upper end of the thumb joint 13 is fixedly connected to the output end of the thumb joint servo 15, and a soft finger 2 is connected to the thumb joint 13 as a thumb; the thumb joint 13 is driven by the thumb joint servo 15 to rotate around the palm base 11, thereby realizing the rotation of the thumb around the palm 1. A multi-finger joint servo 16 is mounted on the other side of the palm base 11. The output end of the multi-finger joint servo 16 is fixedly connected to one side of the multi-finger joint 12. The side of the multi-finger joint 12 connected to the multi-finger joint servo 16 is also rotationally connected to the connecting column on the other side of the palm base 11. The other side of the multi-finger joint 12 is rotationally connected to the upper end of the connector 14. The lower end of the connector 14 is inserted into the upper end of the thumb joint 13 via a connecting shaft, and the connector 14 does not affect the rotation of the thumb joint 13. Multiple soft fingers 2 are mounted on the multi-finger joint 12. The multi-finger joint servo 16 drives the multi-finger joint 12 to rotate around the palm base 11, realizing the rotation of the remaining fingers around the palm 1. The front palm shell 17 and the back palm shell 18 cover the palm and back palm sides of the palm base 11 respectively, encapsulating the thumb joint servo 15 and the multi-finger joint servo 16 within the palm 1.

[0024] The soft finger 2 includes a flexible finger body 21. A flexible sensor layer 26 and an inextensible layer 27 are provided on the side of the flexible finger body 21 near the fingertip from the inside to the outside. The flexible sensor layer 26 is used to sense contact force, so that the dexterous hand structure has a tactile perception function; the inextensible layer 27 has an inextensible physical property, which makes the rigidity of the fingertip side of the soft finger 2 greater than the back side, ensuring that the soft finger 2 bends inward; a partition 25 is provided in the middle of the flexible finger body 21, which divides the hollow interior of the flexible finger body 21 into an upper air cavity 22 and a lower air cavity 23, and the two air cavities are not connected, thereby dividing the soft finger 2 into upper and lower knuckles; the upper air cavity 22 2 and the lower air cavity 23 are respectively connected to the air source through the air pipe, and the air pipe is provided with an electromagnetic valve. The inflation and deflation of the two air cavities are independently controlled, and the finger bending is achieved by inflating and deflation of the air cavity; the upper air cavity 22 and the lower air cavity 23 are respectively provided with a plurality of reinforcing ribs 24 distributed along the width direction of the finger, which are used to enhance the toughness and rigidity of the soft finger 2, so as to reduce the possibility of damage to the finger when the internal air pressure of the finger increases; further, the dorsal side array of the flexible finger body 21 has a plurality of bosses 28 to enhance the rigidity of the dorsal side of the finger, thereby improving the bending ability of the finger. Even when the finger is bent at 180°, the possibility of damage to the finger due to excessive internal air pressure can be avoided.

[0025] The flexible finger body 21 is made of silicone molded, and the flexible sensor layer 26 and the non-extensible layer 27 are placed inside the flexible finger body 21 before solidification. After solidification, the three layers form an integrated structure. The non-extensible layer 27 is made of silk screen.

[0026] The flexible sensor layer 26 includes a plurality of flexible sensors arranged in an array. The flexible sensors are capacitive flexible sensors. When an external force is applied to the surface of the capacitive flexible sensor, the distance between the upper and lower electrodes of the capacitive flexible sensor decreases, and the capacitance of the capacitive flexible sensor will increase as the distance decreases. When the applied external force is removed, the capacitive flexible sensor rebounds and resets, and its capacitance will also return to its initial value. Therefore, the detection of tactile pressure is achieved by detecting the change in capacitance of the capacitive flexible sensor, thereby realizing the tactile perception of the dexterous hand structure.

[0027] Except for the thumb, the number of the remaining fingers can be set according to the actual task, so the multi-finger joints 12 can be two finger joints, three finger joints or four finger joints.

[0028] The working principle and workflow of this utility model are:

[0029] The palm 1 has two degrees of freedom. One degree of freedom is that the thumb joint servo 15 drives the thumb joint 13 to rotate around the palm base 11, realizing the rotation of the thumb around the palm 1; the other degree of freedom is that the multi-finger joint servo 16 drives the multi-finger joint 12 to rotate around the palm base 11, realizing the rotation of the remaining fingers around the palm 1, thereby simulating the movement of human fingers around the palm.

[0030] The finger bending is controlled by inflating the air cavity of the soft finger 2. The air cavity is inflated to increase the internal air pressure. Since the stiffness of the soft finger 2 is greater on the ventral side than on the dorsal side, the knuckle where the air cavity is located will bend and deform toward the ventral side, thereby achieving the bending of the knuckle. The soft finger 2 has three bending modes: upper knuckle, lower knuckle and whole knuckle. Figure 5 . Upper phalanx flexion pattern (see Figure 5 (a) : Inflate the upper air chamber 22, and the upper phalanx will bend and deform, and cooperate with the other fingers to achieve the pinching action of the fingertips. Figure 5 (b) : Inflate the lower air chamber 23, and the lower phalanx will bend and deform, which can realize the gripping action of the finger root phalanx. Overall bending mode (see Figure 5 (c) : The upper air cavity 22 and the lower air cavity 23 are inflated at the same time, and the entire finger is bent and deformed, which cooperates with the other fingers to achieve an envelope-type grasping action of the whole hand.

[0031] Any matters not described in this utility model are applicable to the prior art.

Claims

1. A soft dexterous hand structure with tactile perception function, comprising a palm and soft fingers connected to the palm; characterized in that: The soft finger includes a flexible finger body, and a flexible sensor layer and a non-extensible layer are provided from the inside to the outside on the side of the flexible finger body close to the fingertip. A partition is provided in the middle of the flexible finger body, which divides the hollow interior of the flexible finger body into an upper air cavity and a lower air cavity, and the two air cavities are not connected. The upper air cavity and the lower air cavity are respectively connected to the air source, and the finger bending is achieved by inflating and deflating the air cavity.

2. The soft dexterous hand structure with tactile perception function according to claim 1, characterized in that: The palm includes a palm base, multiple finger joints, a thumb joint, a connecting piece, a thumb joint servo and a multiple finger joint servo; the thumb joint servo is located on one side of the palm base, the lower end of the thumb joint is rotatably connected to one side of the palm base, the upper end of the thumb joint is connected to the output end of the thumb joint servo, and a soft finger is connected to the thumb joint; the multiple finger joint servo is located on the other side of the palm base, the output end of the multiple finger joint servo is connected to one side of the multiple finger joint, the other side of the multiple finger joint is rotatably connected to the upper end of the connecting piece, the lower end of the connecting piece is inserted into the upper end of the thumb joint and does not affect the rotation of the thumb joint; multiple soft fingers are connected to the multiple finger joints.

3. The soft dexterous hand structure with tactile perception function according to claim 2, characterized in that: The multiple finger joints are two finger joints, three finger joints or four finger joints.

4. The soft dexterous hand structure with tactile perception function according to any one of claims 1 to 3, characterized in that: A plurality of reinforcing ribs arranged along the width direction of the finger are respectively provided in the upper air cavity and the lower air cavity, and a plurality of bosses are arrayed on the dorsal side of the flexible finger body.

5. The soft dexterous hand structure with tactile perception function according to claim 4, characterized in that: The flexible sensor layer includes a plurality of flexible sensors arranged in an array, and the flexible sensors are capacitive flexible sensors.

Images