A variable-rigidity flexible gripping system for complex and narrow space operations

Abstract

A variable stiffness flexible grasping system for operations in complex and narrow spaces includes a variable stiffness bending and deforming flexible arm and a foldable end effector. The variable stiffness bending and deforming flexible arm includes a plurality of independent hollow air cavities on the periphery and a variable stiffness fiber blocking cavity in the center. The foldable end effector includes a plurality of fingers, each of which includes a non-stretchable membrane, a plurality of hard sheets and an elastic membrane. The flexible arm achieves multi-degree-of-freedom bending through a three-cavity pneumatic bending design and a central fiber blocking variable stiffness module, making it easy to pass through narrow passages. The end effector achieves multi-state conversion from folding to stretching and then to bending through the cooperation of soft materials, hard sheets and elastic membranes, adapts to objects of different shapes and sizes, and achieves precise grasping. In addition, a retractable flexible wrist is introduced to increase the degree of freedom of axial extension, compensate for position errors, and improve grasping accuracy. The present invention is suitable for robot operations in complex environments, and is particularly suitable for fields such as industrial assembly, post-disaster search and rescue, and marine exploration.

Description

Technical Field

[0001] The invention relates to the technical field of robot grippers, and in particular to a variable-rigidity flexible gripping system for operations in complex and narrow spaces. Background Art

[0002] With the rapid development of industrial automation technology, the demand for flexible grasping systems in complex working environments is increasing. Although traditional rigid robotic arms and grippers are widely used, their adaptability and flexibility are limited due to their large size, heavy weight, high energy consumption, and rigid contact that may cause damage to the target object. These shortcomings are particularly prominent in narrow spaces and unstructured environments. Flexible grasping systems have gradually become a research hotspot in the field of robot end effectors due to their light weight, softness, and adaptability to objects of different shapes and sizes. In particular, flexible grippers based on pneumatic drives and smart materials have performed well in changing stiffness and achieving multifunctional operations. However, compliance also brings defects to flexible grasping systems. At present, most flexible grippers still have limitations in versatility and operating accuracy, and it is difficult to simultaneously meet the flexibility and stability requirements in complex environments. In addition, many variable stiffness technologies based on smart materials are costly and have slow response speeds. In addition, most of the current end gripper actuators have complex control systems, and their flexible grasping deformation, high load capacity, and multifunctional grasping performance are mostly accompanied by the disadvantages of large size and complex design.

[0003] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0004] The main purpose of the present invention is to overcome the defects existing in the above-mentioned background technology and provide a variable-rigidity flexible gripping system for operations in complex and narrow spaces.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A variable stiffness flexible grasping system for complex and narrow space operations, comprising a gripper body and a drive module; the gripper body comprises a variable stiffness bending and deforming flexible arm and a foldable end effector;

[0007] The variable stiffness bending deformation flexible arm includes a plurality of independent hollow air cavities on the periphery and a variable stiffness fiber blocking cavity in the center. The independent hollow air cavity has a corrugated wall surface on the outside, and bending deformation is achieved by air pressure to control the bending direction and angle of the flexible arm. The variable stiffness fiber blocking cavity includes a sealing membrane and a fiber bundle in the sealing membrane. The sealing membrane is connected to the trachea, and the degree of fiber accumulation and blocking is adjusted by negative pressure to achieve the adjustment of the stiffness of the central cavity, thereby adjusting the stiffness of the flexible arm.

[0008] The foldable end effector comprises a plurality of fingers, each of which comprises an inextensible film, a plurality of hard sheets and an elastic film, the plurality of hard sheets are arranged on the inextensible film to form the inner side of a single finger, the gaps between the hard sheets are used as creases to realize the foldability of the finger, the elastic film is connected to the inextensible film on the outer side of the single finger to form a closed space and lead out the trachea; the finger realizes three working states through the change of the inflation state: the finger is folded with the hard sheet as the basic unit in the initial state, and under pneumatic drive, the finger changes from the initial folded state to the extended state, and then changes to the inwardly bent and closed state for grasping;

[0009] The driving module includes an air pump and an air circuit system, wherein the air circuit system includes a flexible arm air circuit and an end effector air circuit, wherein the flexible arm air circuit is used to control the movement of the variable-rigidity bending and deforming flexible arm, and the end effector air circuit is used to control the movement of multiple fingers.

[0010] When working, the control module controls the air pump and the air circuit system to achieve precise grasping operation of the gripper body in a narrow space.

[0011] Furthermore, the multiple fingers are synchronously driven by the same air circuit.

[0012] Furthermore, the gripper body also includes a retractable flexible wrist connected between the variable stiffness bending deformation flexible arm and the foldable end effector, and the retractable flexible wrist includes a bellows telescopic structure, and the bellows telescopic structure is hollow inside and connected to the air pipe. Ventilation generates telescopic movement to achieve fine-tuning of the axial length and compensate for the distance error between the end of the flexible grasping system and the target position.

[0013] Furthermore, the plurality of independent hollow air cavities are axially symmetrically arranged around the variable stiffness fiber blocking cavity.

[0014] Furthermore, the number of the independent hollow air cavities is 3 or more.

[0015] Furthermore, the cross section of the independent hollow air cavity is a concentric sector shape.

[0016] Furthermore, the variable stiffness fiber blocking cavity is cylindrical.

[0017] Furthermore, the number of fingers of the foldable end effector is 3 or more.

[0018] Furthermore, it also includes a perception module, which includes a micro camera arranged on the foldable end effector.

[0019] Furthermore, the foldable end effector comprises an end gripper base, the micro camera is mounted at the center of the end gripper base, and the plurality of fingers are mounted on the end gripper base around the micro camera.

[0020] The perception module is connected to the control module. When working, the control module can comprehensively control the air pump and air path system based on the environment and target object information provided by the perception module through image processing technology and grasping path planning algorithm, so as to realize precise grasping operation of the gripper body in a small space.

[0021] The present invention has the following beneficial effects:

[0022] The present invention provides a variable stiffness flexible grasping system for operations in complex and narrow spaces, which has excellent performance in operations in complex and narrow spaces. The system realizes efficient operations in complex and narrow spaces through the designed variable stiffness bending and deforming flexible arm and foldable end effector. The coordinated design of multiple independent hollow air cavities on the periphery of the flexible arm and the central fiber blocking variable stiffness module allows the system to achieve multi-degree-of-freedom bending and flexible adjustment of the stiffness of the flexible arm in space, and easily pass through narrow channels for grasping operations. The end effector realizes multi-state conversion capabilities through the coordinated design of an inextensible membrane, multiple hard sheets and an elastic membrane, from folding to stretching to bending, so that the system can flexibly adapt to objects of different shapes and sizes, thereby achieving precise grasping. This design not only improves the flexibility and adaptability of the system, but also enhances its load capacity and stability, while maintaining the lightness and compactness of the structure, which is convenient for deployment on a small robot platform.

[0023] Further preferably, by introducing a retractable flexible wrist between the variable stiffness bending deformable flexible arm and the foldable end effector, the system can also achieve more precise axial position adjustment, so that the gripper can better adapt to the position changes of the target object, compensating for the positioning error caused by the flexible characteristics of the grasping system, thereby achieving more precise and stable grasping operations in complex and changeable working environments.

[0024] The system of the present invention can adopt mature pneumatic drive technology and silicone soft materials, which significantly reduces the manufacturing cost while maintaining a high degree of versatility and is suitable for a variety of industrial and scientific research application scenarios. The modular design of the system makes it easy to maintain and upgrade, further enhancing its ability to operate in unstructured environments. In general, the technical solution of the present invention provides an innovative solution for robot operations in complex environments, and is particularly suitable for fields such as industrial assembly, post-disaster search and rescue, and marine exploration, effectively solving the limitations of traditional rigid robotic arms and grippers in these scenarios.

[0025] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1A This is an overall structural diagram of the initial state of the variable stiffness flexible grasping system for complex and narrow space operations according to an embodiment of the present invention.

[0027] Figure 1B for Figure 1A A partial enlarged view of the upper dotted box in .

[0028] Figure 1C for Figure 1A A partial enlarged view of the lower dotted box in .

[0029] Figure 2A This is an overall structural diagram of the working state of an embodiment of the present invention (wherein the end gripper is in a bent grasping state, and the variable stiffness flexible arm is in a bent deformation state).

[0030] Figure 2B for Figure 2A A partial enlarged view of the upper dotted box in .

[0031] Figure 2C for Figure 2A A partial enlarged view of the lower dotted box in .

[0032] Figure 3 4 is a cross section of a variable stiffness flexible arm according to an embodiment of the present invention.

[0033] Figure 4 4 is a longitudinal section of a variable stiffness flexible arm according to an embodiment of the present invention.

[0034] Figure 5 This is a structural diagram of a fiber blocking variable stiffness module according to an embodiment of the present invention.

[0035] Figure 6 This is the folded state (ie, initial state) of the end effector of the embodiment of the present invention.

[0036] Figure 7 This is the extended state of the end effector of the embodiment of the present invention.

[0037] Figure 8 This is the bending state (ie, the working state) of the end effector of the embodiment of the present invention.

[0038] Reference numerals:

[0039] 1. Variable stiffness bending deformation flexible arm, 2. Telescopic flexible wrist, 3. Finger, 4. Module connector, 5. End gripper fixing seat, 6. Air circuit for driving the deformation of the flexible arm, 7. Air circuit of the fiber blocking module, 8. Air circuit of the telescopic flexible wrist, 9. Air circuit of the end effector, 10. Micro camera, 11. Sealing film, 12. Fiber bundle, 13. Camera fixing seat, 14. Pneumatic four-way joint, 15. Rigid sheet, 16. Non-stretchable film, 17. Elastic film. Detailed implementation mode

[0040] The following will give a detailed description of the implementation mode of the present invention. It should be emphasized that the following description is merely exemplary and not intended to limit the scope of the present invention and its applications.

[0041] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, the connection can be for fixing or for coupling or communicating.

[0042] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0043] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present invention, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0044] Refer to Figures 1A to 8 , the embodiment of the present invention provides a variable stiffness flexible grasping system for operating in a complex and narrow space, including a gripper body and a driving module; the gripper body includes a variable stiffness bending deformation flexible arm 1 and a foldable end effector.

[0045] Refer to Figures 1A to 5The variable stiffness bending deformation flexible arm 1 includes a plurality of independent hollow air cavities on the periphery and a variable stiffness fiber blocking cavity in the center. The outer side of the independent hollow air cavity has a corrugated wall surface, and bending deformation is achieved by air pressure to control the bending direction and angle of the flexible arm; the variable stiffness fiber blocking cavity includes a sealing membrane 11 and a fiber bundle 12 in the sealing membrane 11. The sealing membrane 11 is connected to the trachea, and the degree of fiber backlog blocking is adjusted by negative pressure to achieve central cavity stiffness adjustment, thereby adjusting the stiffness of the flexible arm.

[0046] The foldable end effector includes multiple fingers 3, each finger 3 includes a non-stretchable membrane 16, multiple hard sheets 15 and an elastic membrane 17, the multiple hard sheets 15 are arranged and pasted on the non-stretchable membrane 16 to form the inner side of a single finger 3, and the gaps between the hard sheets 15 are used as creases to realize the foldability of the finger 3, and the elastic membrane 17 is connected to the non-stretchable membrane 16 on the outer side of the single finger 3 to form a closed space and lead out the trachea; the finger 3 realizes three working states by changing the inflation state: the finger 3 is initially folded with the hard sheet 15 as the basic unit, and under pneumatic drive, the finger 3 changes from the initial folded state to the stretched state, and then to the inwardly bent and closed state for grasping. In the initial folded state, in which the fingers 3 are not inflated, the two layers of film are stuck together, occupying a very small space; in the extended state, by inflating the fingers 3, the fingers 3 are extended from the folded state to a two-dimensional plane state, and the space occupied by the gripper becomes larger; and in the bent state, by continuing to inflate the fingers 3, the elastic film 17 is stretched and lengthened, the length of the non-stretchable film 16 covered with the hard sheet 15 remains unchanged, the fingers 3 bend toward the side of the non-stretchable layer, and each finger 3 is retracted inward, thereby achieving the envelopment and grasping of the target object.

[0047] The driving module includes an air pump and an air circuit system, and the air circuit system includes a flexible arm air circuit and an end effector air circuit 9, wherein the flexible arm air circuit includes a flexible arm driving deformation air circuit 6 and a fiber blocking module air circuit 7, which are used to control the movement of the variable stiffness bending deformation flexible arm 1, and the end effector air circuit is used to control the movement of multiple fingers 3.

[0048] During operation, the control module (not shown) controls the air pump and the air path system connecting multiple independent hollow air cavities, the central variable stiffness fiber blocking cavity and multiple fingers 3 to achieve precise grasping operation of the gripper body in a narrow space.

[0049] In the grasping system of the present invention, the foldable end effector cooperates with the flexible arm that can flexibly bend and deform, enabling it to pass through narrow spaces and adapt to complex environments. After reaching the target operation point, the end effector extends and bends to perform operations such as grasping, and the arm enhances its rigidity by varying stiffness. The gripper system provided by the present invention has the advantages of flexible deformation, superior load capacity, higher precision, and a lightweight and compact structure, and has good operation advantages in narrow spaces and unstructured environments. Through multi-module collaborative design, this system can efficiently pass through narrow spaces and complete precise grasping operations at the target position, with the advantages of low cost and strong adaptability, providing an effective solution for robot operations in narrow spaces and unstructured environments.

[0050] In a preferred embodiment, the gripper body further includes a telescopic flexible wrist 2 connected between the variable-stiffness flexibly deformable arm 1 and the foldable end effector. The telescopic flexible wrist 2 includes a bellows telescopic structure. The interior of the bellows telescopic structure is hollow and communicates with the air passage 8 of the telescopic flexible wrist, and inflation generates telescopic movement to achieve fine adjustment of the axial length and compensate for the distance error between the end of the flexible grasping system and the target position.

[0051] By introducing the telescopic flexible wrist 2 between the variable-stiffness flexibly deformable arm 1 and the foldable end effector, the system can achieve more precise axial position adjustment. Utilizing the bellows design of the telescopic flexible wrist 2, inflation is used to achieve telescopic movement, enabling the system to flexibly adjust the distance to the operation point while maintaining light weight and compactness. This optimized design not only improves the grasping accuracy but also enhances the flexibility of the system, enabling the gripper to better adapt to the position changes of the target object, compensating for the positioning error caused by the flexible characteristics, and thus achieving more precise and stable grasping operations in complex and changeable working environments.

[0052] In a preferred embodiment, a plurality of the independent hollow air cavities are axially symmetrically arranged around the variable-stiffness fiber blocking cavity. The number of the independent hollow air cavities is 3 or more. In a preferred embodiment, the cross-section of the independent hollow air cavity is a concentric sector. The variable-stiffness fiber blocking cavity is cylindrical.

[0053] In a preferred embodiment, the number of fingers 3 of the foldable end effector is 3 or more. In a preferred embodiment, the multiple fingers 3 are synchronously driven by the same air passage.

[0054] In some embodiments, the system includes a perception module, and the perception module includes a micro camera 10 disposed on the foldable end effector. In a preferred embodiment, the foldable end effector includes an end gripper base, the micro camera is installed at the center of the end gripper base, and the plurality of fingers 3 are installed on the end gripper base around the micro camera. The perception module is connected to a control module (not shown). When working, the control module can comprehensively control the air pump and the air path system according to the environment and target information provided by the perception module through image processing technology and grasping path planning algorithm, so as to realize the precise grasping operation of the gripper body in a small space.

[0055] The present invention provides a superior performance grasping solution for the challenges of working in complex and narrow spaces. By introducing the innovative design of variable stiffness flexible arms and foldable end effectors, as well as the further design of retractable flexible wrist 2, the present invention overcomes the limitations of traditional grasping systems in terms of flexibility, load capacity and accuracy, and the foldable design makes the overall structure light and compact, and can efficiently adapt to narrow and complex and changing environmental conditions.

[0056] The specific embodiments of the present invention are further described below.

[0057] A variable stiffness flexible grasping system for operations in complex and narrow spaces. The gripper system includes a gripper body, a sensing module, a driving module and a control module. The mechanical body of the gripper includes a variable stiffness bending deformation flexible arm 1, a retractable flexible wrist 2 and a foldable end effector; the driving module is mainly an air pump for providing driving force for the gripper; the control module is mainly for the control of six air circuits, and the sensing module includes a micro camera installed on the end effector. The variable stiffness bending deformation flexible arm 1 and the retractable flexible wrist 2 of the gripper body can be made of silicone soft material. The flexible arm contains three axially symmetrical air cavities and a central variable stiffness fiber blocking cavity. The retractable flexible wrist 2 is a bellows telescopic structure containing an air cavity. The foldable end effector consists of three identical fingers 3, which are composed of a soft material (elastic film 17), an inextensible plastic film (inextensible film 16) and a regularly arranged hard sheet 15 fixed on the plastic film. The hard sheet 15 can be folded as a basic unit. Under pneumatic drive, the finger 3 can be changed from an initial folded state to an extended state and then to a final bent state. The three parts are connected by connectors to form a grasping system. During operation, the environment and information about the grasping target are fed back by the micro camera at the end. The foldable end effector cooperates with the flexible arm that can be bent and deformed flexibly, so that it can pass through a small space and adapt to a complex environment. After reaching the target operation point, the end effector stretches and bends to perform operations such as grasping. The arm increases rigidity by changing its stiffness. Adjusting the retractable flexible wrist 2 can adjust the distance from the operation point and compensate for the error of the flexible grasping system. The gripper system provided by the present invention has the advantages of flexible deformation, superior load capacity, higher precision, light and compact structure, etc., and has good operation advantages in small spaces and non-structural environments.

[0058] The variable stiffness flexible grasping system mainly includes the following parts:

[0059] ① Gripper body structure. The gripper body includes a variable stiffness bending deformation flexible arm 1, a retractable flexible wrist 2, and a foldable end effector. Variable stiffness bending deformation flexible arm 1: Made of silicone material, it contains three axially symmetrical air cavities and a central variable stiffness fiber blocking cavity. The three air cavities are independently controlled, and the bending direction and angle are adjusted by inflation; the central fiber blocking cavity enhances stiffness through negative pressure, realizes the switching of flexibility and rigidity, and enhances the load capacity. Retractable flexible wrist 2: It adopts a bellows design and contains an air cavity made of silicone soft material. Inflation or exhaust adjusts the length of the bellows, accurately adjusts the distance between the end of the system and the target, and compensates for the operation error. Foldable end effector: It consists of three fingers 3, each finger 3 is made of soft material, non-stretchable plastic film and regularly arranged hard sheets 15. The finger 3 can be changed from a folded state to an extended state under pneumatic drive, and further bent to wrap the target to achieve precise grasping. The three parts are assembled into one through connectors to achieve efficient collaborative work.

[0060] ② Drive module. The drive module is mainly composed of an air pump and an air circuit system, providing independent six-way pneumatic control: the variable stiffness flexible arm adopts four-way control, which is used for the bending adjustment of the three air cavities and the stiffness adjustment of the central cavity respectively. The retractable flexible wrist 2 is controlled by one channel for fine-tuning the axial length. The end effector adopts one channel control to drive the folding, extension and bending operations of the three fingers 3 at the same time. Each air circuit is equipped with a pressure sensor, an air pressure regulating valve and an electromagnetic switch valve to ensure the accuracy and stability of the air circuit operation.

[0061] ③ Perception and control module. Perception can be achieved through a micro camera installed on the end effector. It captures information about the environment and target objects in real time to guide the gripper operation. The control module adjusts the trajectory, stiffness, and gripping state of the system in real time based on the camera feedback.

[0062] The following describes in detail the design and operation of the variable stiffness flexible gripping system of the embodiment, covering the structural design, working principle, functional description of key components, and the overall operation process of the system.

[0063] Gripper body structure design:

[0064] The gripper body includes the following key components: a variable stiffness bending and deformation flexible arm 1, a retractable flexible wrist 2, and a foldable end effector.

[0065] The variable stiffness bending deformation flexible arm 1 is made of silicone material, and has three axially symmetrical independent hollow air cavities, with a concentric fan-shaped cross section. The wall surface on the outer side of the air cavity is corrugated. The corrugated design makes it easier for the air cavity to produce a larger length change when the inflation pressure increases. The air cavity is connected to the air pipe and is led out from the bottom of the gripping system. The center is a variable stiffness chamber, in which a fiber blocking module is embedded. The module consists of a fiber bundle 12 and a cylindrical flexible sealing film outside the fiber bundle 12. The sealing film 11 is also connected to the air pipe and led out from the bottom of the flexible arm. In the original state, no air pressure is applied to the three air cavities and the fiber blocking module. The length of the air cavity increases when it is inflated, and the length of the uninflated air cavity remains unchanged. Therefore, the flexible arm can bend to the opposite side of the inflated air cavity to achieve deformation. By choosing whether to apply air pressure and the amount of air pressure applied, bending and deformation in any direction in space can be achieved. When the fiber blocking module applies negative pressure, the fiber materials in the sealing membrane 11 are pressed against each other more strongly, the friction increases, and the stiffness of the entire module increases, thereby achieving variable stiffness and maintaining the current shape of the flexible arm.

[0066] The retractable flexible wrist 2 adopts a bellows design, which is hollow inside and connected to an air pipe, which is led out from the bottom of the module. When the inflation pressure increases, the module can produce a telescopic movement to achieve length adjustment within a small range, thereby compensating for the distance error between the actual position of the end of the flexible grasping system and the target position.

[0067] The foldable end effector is composed of soft material, non-stretchable plastic film and regularly arranged hard sheets 15. The hard sheet 15 is pasted on the non-stretchable plastic film to form the inner side of a single finger 3, and the elastic film 17 with the same shape as the inner side is cut to form the outer side of a single finger 3. The edges of the two layers of material are pasted together to form a closed space, that is, a single finger 3. The end effector is composed of three identical fingers 3, which are fixed on the end gripper fixing seat 5, and all of them lead out of the trachea. The trachea converges into an air path through the pneumatic four-way connector on the end gripper fixing seat 5, that is, the three fingers 3 are driven by the same air path. The foldable end effector has three states. The first is the initial folding state, the finger 3 is not inflated, the two layers of material are pasted together, and the finger 3 is folded with the gap between the hard sheets 15 as the crease, occupying a very small space. The second is the extended state, the finger 3 is inflated, and the finger 3 is extended from the folded state to a two-dimensional plane state, but it has not expanded further, and the gripper occupies a larger space. Finally, in the bending state, the finger 3 is continuously inflated, the finger 3 expands, the elastic material layer is stretched and lengthened, and the inextensible layer covered with the hard sheet 15 remains unchanged in length, so the finger 3 bends toward the inextensible layer side, and the gripper can envelop the target at this time.

[0068] Drive module design:

[0069] The drive module is mainly composed of an air pump and an air circuit system, with a total of 6 independent pneumatic controls. The variable stiffness bending and deformation flexible arm, the retractable flexible wrist, and the foldable end effector are controlled by 4, 1, and 1 channels respectively. Each channel is equipped with air pressure feedback, air pressure regulation, and air circuit switch modules.

[0070] Perception module:

[0071] The perception module integrates a micro camera installed on the end gripper base to collect real-time information about the environment and target objects. It provides intelligent decision support for the system through image processing technology and grasping path planning algorithm.

[0072] Control Module:

[0073] The control module comprehensively controls the air pump and air circuit system, and adjusts the system's motion trajectory, stiffness configuration, and end-gripping status based on real-time environmental information fed back by the camera.

[0074] Through modular design, the system realizes the coordinated work of the flexible arm, wrist and end effector. The flexible arm overcomes the deformation error caused by the flexible material through variable stiffness adjustment and precise bending; the wrist reaches the target position through telescopic adjustment; and the end effector completes the target grasping under the guidance of the micro camera.

[0075] When working, the operation process includes:

[0076] The system is initialized, the air circuit is in an uninflated state, and the gripper remains in a folded state.

[0077] The camera collects target location and environmental information and generates an operation path.

[0078] The flexible arm gradually bends according to path planning, passes through narrow spaces, and approaches the target object.

[0079] The wrist is adjusted to the appropriate length and positioned to the target grasping position.

[0080] The end effector unfolds and bends to grasp the target object.

[0081] The flexible arms increase stiffness through negative pressure, maintaining shape and grasping stability.

[0082] The variable stiffness flexible gripping system of the present invention significantly improves the adaptability and operational performance of operations in complex and narrow spaces through modular design and innovative collaborative control. Compared with the prior art, it has the following technical effects and advantages:

[0083] ①Strong flexible deformation ability

[0084] The flexible arm adopts a three-cavity pneumatic bending design, and with the central fiber blocking variable stiffness module, it can achieve two-degree-of-freedom bending in space and easily pass through narrow channels. The retractable flexible wrist increases the freedom of axial extension of the system, and the end effector uses a combination of soft materials and hard sheets to achieve multi-state conversion from folding to extension and then to bending, ensuring the efficient operation of the system in limited space.

[0085] By introducing a three-cavity bending pneumatic structure and fiber blocking stiffness adjustment technology, combined with a polymorphic foldable actuator at the end, this system overcomes the limitations of traditional grippers that are rigidly fixed and difficult to explore and pass through narrow spaces.

[0086] ② Rigid-flexible combination enhances stability and load capacity

[0087] The flexible arm enhances its load capacity and maintains shape stability through the variable stiffness function to adapt to various grasping task requirements. Compared with variable stiffness technologies based on complex structural design and intelligent materials, the variable stiffness technology based on fiber blocking has a fast response, stable effect, and low deployment effort. The retractable flexible wrist can realize axial distance adjustment, compensate for the position error of the flexible system, and ensure grasping accuracy.

[0088] Combining the flexible arm center stiffness adjustment module with the bellows wrist telescopic design, the system maintains flexibility while having high rigidity support capabilities, achieving an optimal balance between flexibility and stability.

[0089] ③Lightweight and compact structure, easy to deploy

[0090] The system adopts a modular design, and each component is lightweight and compact, suitable for installation on a small robot platform. In addition, the foldable end effector can be stretched to several times the volume of its original folded state, making it easy to explore and pass through narrow spaces.

[0091] The system is highly adaptable in confined spaces and unstructured environments, can flexibly perform a variety of grasping tasks, and is more compact, lightweight and versatile than traditional robotic arms.

[0092] ④Low cost and strong versatility

[0093] This system uses pneumatic drive technology and silicone soft materials, with low manufacturing cost, strong versatility, and is suitable for a variety of industrial and scientific research application scenarios.

[0094] In general, the technical solution of the present invention is particularly suitable for robot operations in complex environments, such as industrial assembly, post-disaster search and rescue, and ocean exploration, and provides an innovative solution for efficient operations in unstructured environments.

[0095] The above content is a further detailed description of the present invention in combination with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be regarded as belonging to the protection scope of the present invention. In the description of this specification, the description of the reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the absence of mutual contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A variable stiffness flexible grasping system for complex and narrow space operations, characterized in that: It includes a gripper body and a driving module; the gripper body includes a variable stiffness bending and deforming flexible arm and a foldable end effector; The variable stiffness bending deformation flexible arm includes a plurality of independent hollow air cavities on the periphery and a single variable stiffness fiber blocking cavity located at the center of the variable stiffness bending deformation flexible arm. The number of the independent hollow air cavities is 3, and the 3 independent hollow air cavities are axially symmetrically arranged around the variable stiffness fiber blocking cavity. The independent hollow air cavity has a corrugated wall surface on the outside, and bending deformation is achieved by air pressure to control the bending direction and angle of the flexible arm; the variable stiffness fiber blocking cavity is a cylindrical cavity located at the center of the variable stiffness bending deformation flexible arm, and a sealing membrane and a fiber bundle in the sealing membrane are embedded in the variable stiffness fiber blocking cavity, and the sealing membrane is connected to the trachea, and the degree of fiber backlog blocking is adjusted by negative pressure to achieve central cavity stiffness adjustment, thereby adjusting the stiffness of the flexible arm; The foldable end effector comprises a plurality of fingers, each of which comprises an inextensible film, a plurality of hard sheets and an elastic film, wherein the plurality of hard sheets are arranged on the inextensible film to form the inner side of a single finger, and the gaps between the hard sheets are used as creases to realize the foldability of the finger, and the elastic film is connected to the inextensible film on the outer side of the single finger to form a closed space and lead out the trachea; the finger realizes three working states through the change of the inflation state: in the initial state, the finger is folded with the hard sheet as the basic unit, and under pneumatic drive, the finger changes from the initial folded state to the extended state, and then changes to the inwardly bent and closed state for grasping; The driving module includes an air pump and an air circuit system, wherein the air circuit system includes a flexible arm air circuit and an end effector air circuit, wherein the flexible arm air circuit is used to control the movement of the variable stiffness bending deformation flexible arm, and the end effector air circuit is used to control the movement of multiple fingers; The gripper body also includes a retractable flexible wrist connected between the variable stiffness bending deformation flexible arm and the foldable end effector, the retractable flexible wrist includes a bellows telescopic structure, the bellows telescopic structure serves as the wrist at the end of the variable stiffness bending deformation flexible arm, and its length is less than the length of the variable stiffness bending deformation flexible arm. The bellows telescopic structure is hollow inside and connected to the air pipe, and ventilation generates telescopic movement to achieve fine adjustment of the axial length and compensate for the distance error between the end of the flexible grasping system and the target position; Through modular design, the flexible arm, wrist and end effector can work together.

2. The variable stiffness flexible grasping system for complex and narrow space operations as claimed in claim 1, characterized in that: The multiple fingers are synchronously driven by the same air circuit.

3. The variable stiffness flexible gripping system for complex and narrow space operations according to any one of claims 1 to 2, characterized in that: The cross section of the independent hollow air cavity is a concentric sector.

4. The variable stiffness flexible gripping system for complex and narrow space operations according to any one of claims 1 to 2, characterized in that: The number of fingers of the foldable end effector is 3 or more.

5. The variable stiffness flexible gripping system for complex and narrow space operations according to any one of claims 1 to 2, characterized in that: It also includes a perception module, which includes a micro camera arranged on the foldable end effector.

6. The variable stiffness flexible grasping system for complex and narrow space operations as claimed in claim 5, characterized in that: The foldable end effector comprises an end gripper base, the micro camera is installed at the center of the end gripper base, and the plurality of fingers are installed on the end gripper base around the micro camera.

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