A thin sheet-like flexible woven gripper with variable stiffness

Abstract

This invention provides a variable stiffness, sheet-like flexible woven gripper, relating to the field of soft robotics. It includes a flexible woven mesh, an end effector, several drive wires, and a drive device. The center of the flexible woven mesh is fixed to the end effector. The drive wires are placed within the flexible woven mesh, and the drive wires are arranged circumferentially at intervals around the end effector. One end of each drive wire is fixed to the outer edge of the flexible woven mesh, and the other end passes through the end effector and is connected to the drive device. This variable stiffness, sheet-like flexible woven gripper, in its flexible state, can change its shape and wrap around the object it grasps via the drive wires, and can enhance its stiffness and increase its grasping force through variable stiffness.

Description

Technical Field

[0001] This invention relates to the field of soft robot technology, specifically to a thin, flexible woven gripper with variable stiffness. Background Technology

[0002] The application scenarios of robotic gripping are becoming increasingly complex, often requiring grippers to possess versatility and high adaptability to effectively grasp objects of various shapes and materials. For eggs and fruits in the food industry, or precision components in the electronics industry, traditional grippers lack precise force control, easily applying excessive pressure and causing damage. In household environments where various everyday items such as tableware, books, and toys need to be grasped, traditional soft grippers struggle to adapt to objects of different shapes, sizes, and materials, leading to inconvenience or failure. In complex ruin environments, traditional soft grippers struggle to operate flexibly in narrow, irregular spaces. Current soft grippers face certain limitations in their adaptability to gripped objects and environments. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] To address the shortcomings of existing technologies, this invention provides a thin, flexible woven gripper with variable stiffness, which solves the problems mentioned in the background section.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a thin sheet-like flexible woven gripper with variable stiffness, comprising a flexible woven mesh, an end support, a plurality of drive wires, and a drive device. The center of the flexible woven mesh is fixed on the end support, the drive wires are placed inside the flexible woven mesh, and the plurality of drive wires are arranged circumferentially at intervals around the end support. One end of the drive wire is fixed to the outer edge of the flexible woven mesh, and the other end passes through the end support and is connected to the drive device.

[0007] Preferably, the flexible woven mesh is made of several horizontal and vertical fine threads woven alternately. Some of the horizontal or vertical fine threads are made of capillary material made of hollow capillary variable stiffness material, and the ends of two adjacent capillary material threads are connected by silicone tube end connectors.

[0008] Preferably, it also includes a stiffness control device that can change the stiffness of the capillary material wire.

[0009] Preferably, the stiffness control device includes a heat medium source, a cold medium source, a liquid pump, and a recovery container. The heat medium source and the cold medium source are connected in parallel at the inlet of the liquid pump. The outlet of the liquid pump is connected to the inlet of the first end of the capillary material wire, and the outlet of the last end of the capillary material wire is connected to the recovery container.

[0010] Preferably, the end bracket includes a disc and a screw. One side of the disc has a boss to provide space for the movement of the gripper, and the other side has a buckle for placing the screw. The flexible woven mesh is installed in the buckle by the screw.

[0011] Preferably, the capillary material filament can be made of shape memory polymer (SWP) or thermoplastic elastomer (TPE).

[0012] (III) Beneficial Effects

[0013] This invention provides a thin, flexible woven gripper with variable stiffness. It offers the following advantages:

[0014] 1. This variable stiffness thin sheet-like flexible woven gripper can change its shape and wrap around the object being gripped by driving filaments in its flexible state, and can enhance its stiffness and increase its gripping force by changing its stiffness.

[0015] 2. This variable stiffness thin sheet-like flexible woven gripper uses a drive wire to drive the flexible woven mesh, which can adapt to the shape of the object being gripped, reduce the squeezing force on the object being gripped, and adapt to operation in confined spaces.

[0016] 3. This variable stiffness thin-sheet flexible woven gripper can change the gripping force of the woven mesh by pulling with four drive wires, thereby avoiding damage to fragile items. Attached Figure Description

[0017] Figure 1 This is a diagram showing the unfolded state of the flexible woven mesh of the present invention;

[0018] Figure 2 This is a diagram showing the tensioned gripping state of the flexible woven mesh of the present invention;

[0019] Figure 3 This is a partially enlarged structural diagram of the flexible woven mesh of the present invention;

[0020] Figure 4 This is a schematic diagram of the heat exchange system of the flexible woven mesh of the present invention.

[0021] In the diagram: 1 Flexible woven mesh, 2 Drive wire, 3 End support, 4 Screw, 5 Fastener, 6 Disc, 7 Horizontal fine wire, 8 Vertical fine wire, 9 Capillary material fine wire, 10 Heat medium source, 11 Cold medium source, 12 Liquid pump, 13 Recovery container, 14 End connector. Detailed Implementation

[0022] This invention provides a thin, flexible woven gripper with variable stiffness, such as... Figure 1-4 As shown, it includes a flexible woven mesh 1, an end support 3, several drive wires 2, and a drive device.

[0023] like Figure 1 As shown, the flexible woven mesh 1 is a thin sheet. The geometric center of the flexible woven mesh 1 is fixed on the end support 3. The drive wires 2 are placed inside the flexible woven mesh 1. In this embodiment, four drive wires 2 are arranged in a circumferential pattern around the end support 3. One end of each drive wire 2 is fixed to the outer edge of the flexible woven mesh 1, and the other end passes through the end support 3 and is connected to the drive device. The drive device mainly consists of a motor and a take-up reel for winding the drive wires 2. The tension of the drive wires 2 is controlled by rotating the take-up reel with the motor. Each drive wire 2 is controlled by a separate motor. In use, the gripper can wrap the object being gripped simply by pulling the drive wires 2 through the drive device.

[0024] like Figure 2 As shown, the end bracket 3 includes a disc 6 and screws 4. One side of the disc 6 has a boss to provide space for the gripper's movement, and the other side has a fastening surface 5 for placing the screws 4. The flexible woven mesh 1 is mounted in the fastening surface 5 by the screws 4. Four holes are provided on the disc 6 for the drive wire 2 to pass through, allowing the drive wire 2 to apply force to the flexible woven mesh 1.

[0025] like Figure 3 As shown, the flexible woven mesh 1 is woven from several alternating transverse fine threads 7 and longitudinal fine threads 8. Specifically, based on the multiple transverse fine threads 7, the longitudinal fine threads 8 pass through the transverse fine threads 7 sequentially in the longitudinal direction, while ensuring that adjacent longitudinal fine threads 8 pass through the transverse threads in opposite ways. This results in a flexible woven mesh 1 with a certain rigidity in the transverse direction. Some of the transverse fine threads 7 or longitudinal fine threads 8 are made of capillary material 9, which is a hollow capillary-shaped variable stiffness material. Adjacent capillary material 9 are connected end to end by silicone tube connectors 14. The rigidity of the structure can be changed by introducing hot and cold water.

[0026] Specifically, this device also includes a stiffness control device that can change the stiffness of the capillary material wire 9.

[0027] like Figure 4 As shown, the stiffness control device includes a heat source 10, a cold source 11, a liquid pump 12, and a recovery container 13. A three-way solenoid valve is installed at the inlet of the liquid pump 12 to switch between the heat source 10 and the cold source 11. The heat source 10 and the cold source 11 are connected in parallel to the three-way solenoid valve at the inlet of the liquid pump 12. The outlet of the liquid pump 12 is connected to the inlet of the first end of the capillary material wire 9, and the outlet of the last end of the capillary material wire 9 is connected to the recovery container 13.

[0028] The specific control principle of the stiffness control device is as follows: the liquid pump 12 can inject the hot or cold medium from the heat source 10 or the cold source 11 into the capillary material filaments 9 made of capillary material. With the connection of the end connector 14, all the capillary material filaments 9 form a passage, so the medium can fill the entire flexible braided mesh 1, thereby changing the stiffness of the flexible braided mesh 1. After the medium transfer is completed, the waste medium is recycled to the recycling container 13 through the outlet of the braided thread. When it is necessary to increase the stiffness of the flexible braided mesh 1, the liquid pump 12 works to introduce the cold medium into the capillary material filaments 9. The elastic modulus of the capillary material increases significantly at low temperature, increasing the stiffness of the braided mesh and completing the gripping of the object.

[0029] The material of the capillary material filament 9 can be a shape memory polymer (SWP) or a thermoplastic elastomer (TPE).

[0030] Working principle: such as Figure 1 As shown, when stationary, the flexible woven mesh 1 is in an open position. When an object is detected being clamped, the drive wire 2 is pulled by the drive device, causing the flexible woven mesh 1 to deform. Different tensions are applied to the four drive wires 2, and the flexible woven mesh 1 will deform as shown. Figure 2 The contraction shown can effectively adapt to objects of different shapes, conforming to the object's shape and wrapping it. At this time, the variable stiffness capillary material wire 9 increases its stiffness by introducing a cold medium to lower its temperature, ensuring a certain gripping strength on the object. After gripping the object and moving it to the target position, the drive wire 2 can be released while a hot medium is introduced into the capillary material wire 9 to heat the phase-change variable stiffness wire. The strain energy of the ordinary wire can drive the gripping structure to return to its initial open state. Figure 1 And release the object being held.

[0031] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A thin, flexible woven gripper with variable stiffness, characterized in that: The device includes a flexible woven mesh (1), an end support (3), several drive wires (2), and a drive device. The center of the flexible woven mesh (1) is fixed on the end support (3). The drive wires (2) are placed inside the flexible woven mesh (1). The several drive wires (2) are arranged circumferentially with the end support (3) as the center. One end of the drive wire (2) is fixed to the outer edge of the flexible woven mesh (1), and the other end passes through the end support (3) and is connected to the drive device. The flexible woven mesh (1) is woven from several transverse fine wires (7) and longitudinal fine wires (8) alternately. Some of the transverse fine wires (7) or longitudinal fine wires (8) are hollow capillary-shaped. The capillary material wires (9) are made of variable stiffness material, and the ends of two adjacent capillary material wires (9) are connected by silicone tube end connectors (14); it also includes a stiffness control device that can change the stiffness of the capillary material wires (9); the stiffness control device includes a heat medium source (10), a cold medium source (11), a liquid pump (12), and a recovery container (13). The heat medium source (10) and the cold medium source (11) are connected in parallel to the liquid inlet of the liquid pump (12). The outlet of the liquid pump (12) is connected to the inlet of the first end of the capillary material wire (9), and the outlet of the last end of the capillary material wire (9) is connected to the recovery container (13).

2. The variable stiffness sheet-like flexible woven gripper according to claim 1, characterized in that: The end bracket (3) includes a disc (6) and a screw (4). The disc (6) has a boss on one side to provide space for the movement of the gripper, and a buckle (5) on the other side for placing the screw (4). The flexible woven mesh (1) is installed in the buckle (5) by the screw (4).

3. A variable stiffness sheet-like flexible woven gripper according to claim 1, characterized in that: The material of the capillary material filament (9) can be a shape memory polymer (SWP) or a thermoplastic elastomer (TPE).

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