A flexible adaptive grasping finger based on origami structure and method

Abstract

The application discloses a kind of flexible adaptive gripping finger based on paper folding structure and method, it is related to manipulator technical field.The finger includes finger seat and at least two finger body, finger body includes joint module, finger segment module and connecting piece;Joint module is the first hollow body formed by triangle variant Yoshimura paper folding structure, its back side is equipped with air bag, ventral side is opened first guide hole;Finger segment module is the second hollow body;Connecting piece is respectively with joint module and finger segment module detachably connected;First cable is connected the ventral side of last end finger segment module by first guide hole, second cable is connected the middle position of last end finger segment module by second guide hole on connecting piece.The application adopts paper folding structure and air-ropes hybrid drive, by the layered control strategy of "aerodynamic quick envelope+rope event driving", realizes that structure simplification, control is reliable, maintenance is convenient, and has adaptive gripping capacity, especially suitable for agricultural picking and other complex environment.

Description

Technical Field

[0001] This invention relates to the field of robotic arm technology, and more specifically to a flexible adaptive grasping finger based on origami structure and a method thereof. Background Technology

[0002] With the continuous development of agricultural automation technology, robotics is showing broad application prospects in precision operations such as fruit and vegetable harvesting. As a key component that directly interacts with the object being harvested, the performance of the end effector directly determines the success rate of harvesting and the integrity of the fruit. However, existing grasping devices for fruit harvesting still face many technical bottlenecks, making it difficult to meet the comprehensive needs of agricultural production for high efficiency, flexibility, low cost, and ease of maintenance.

[0003] While traditional rigid robotic arms offer advantages such as structural stability and controllable gripping force, their rigid contact method can easily cause mechanical damage to the fruit surface, especially delicate small and medium-sized fruits. To address this issue, researchers have recently proposed various soft grippers that utilize the constitutive properties of flexible materials to achieve flexible grasping.

[0004] However, existing soft grippers generally suffer from problems such as complex structures and strong drive coupling. This coupling of drive functions makes it difficult to balance compliance and gripping force. Furthermore, their control processes typically involve complex force / position closed-loop algorithms, making system debugging difficult. Moreover, the maintenance costs are extremely high should a sensor or drive component fail, hindering their widespread use in agricultural environments. In addition, the structures of existing flexible gripping fingers are mostly integrally molded, with low modularity, making it difficult to quickly reconfigure them according to the size and shape of different fruits.

[0005] In summary, the existing technology lacks a flexible grasping finger that is structurally simplified, reliably controlled, easy to maintain, and possesses adaptive grasping capabilities. Summary of the Invention

[0006] The purpose of this invention is to provide a flexible adaptive gripping finger and method based on origami structure, which has adaptive gripping capability and is simple in structure, reliable in control and convenient in maintenance.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A flexible adaptive grasping finger based on an origami structure includes a finger base and at least two finger bodies disposed on the finger base, wherein the finger bodies include:

[0009] The joint module is configured as a first hollow body formed by a triangular variant Yoshimura origami structure, with an air bladder on its back side and several first guide holes on its ventral side. The air bladders are in a single-row series structure and share a common air passage.

[0010] The finger segment module is configured as a second hollow body and is connected to the end of the joint module;

[0011] The connector is fixedly connected to the joint module and the finger segment module respectively. A first guide hole is opened on the ventral side of the connector, and a second guide hole is opened in the middle position of the connector.

[0012] The first cable has one end passing through several first guide holes and connected to the ventral side of the last finger segment module, and the other end connected to the first cable drive mechanism.

[0013] The second cable passes through several second guide holes at one end and connects to the middle position of the last finger segment module at the other end, while the second cable is connected to the second cable drive mechanism.

[0014] Furthermore, when the airbag is inflated, it drives the dorsal side of the joint module to extend and the ventral side to contract, causing the finger to bend inward.

[0015] When the first rope is tightened by the first rope drive mechanism, the finger is driven to bend further inward or the preset tension displacement increment of the first rope is increased.

[0016] When the second cable is tightened by the second cable drive mechanism, the finger body is driven to reset.

[0017] Furthermore, the upper and lower triangles of the Yoshimura origami structure are joined together to form a rhombus, and pre-fold creases are provided at the short diagonal position.

[0018] Furthermore, the orthographic projection of the airbag corresponds to the rhomboid region, and the airbag is connected to the rhomboid region.

[0019] Furthermore, the airbag is connected to an air source via an air passage, and a solenoid valve is installed on the air passage.

[0020] Furthermore, the inner and / or outer surfaces of the triangular variant Yoshimura origami structure are covered with a flexible layer.

[0021] Furthermore, the finger segment module includes a root finger segment module and a fingertip finger segment module, and the outer contour of the root finger segment module and / or the fingertip finger segment module is frustoconical.

[0022] Furthermore, the connector includes:

[0023] The finger segment connector has a first protrusion on its back side for connecting with the inner wall of the second hollow body, and an external threaded post on its front side for connecting with the internal threaded hole on the joint end connector.

[0024] The joint end connector has a second protrusion on its back for connecting with the inner wall of the first hollow body, and an internal threaded hole on its front for connecting with the external threaded post on the finger end connector.

[0025] Furthermore, the ventral side of the distal finger segment module is covered with a silicone skin, and a thin-film pressure sensor is attached to the inner side of the silicone skin. The output of the thin-film pressure sensor is connected to a voltage comparator module, which is used to convert the analog force signal into a digital tactile event signal.

[0026] A flexible adaptive grasping method, applying the above-mentioned flexible adaptive grasping finger based on origami structure, the method process is as follows:

[0027] S1, pneumatic rapid envelope;

[0028] Inflate the airbag with gas, causing the fingers to bend inward to form an initial grasping configuration;

[0029] S2, rope-driven event-driven precision grasping;

[0030] The first cable drive mechanism gradually tightens the first cable, drives the finger to bend further inward, and stops the first cable tightening action of the corresponding finger when it detects that the finger is in contact with the grasping object.

[0031] S3, constant deformation retention;

[0032] After all fingers detect contact with the object being grasped, the preset tension displacement increment of the first rope is uniformly increased to achieve open-loop control of the grasping force.

[0033] S4, finger repositioning;

[0034] The first cable drive mechanism releases the first cable, the airbag deflates, and the second cable drive mechanism tightens the second cable, driving all fingers to reset.

[0035] Compared with existing technologies, the flexible adaptive gripping finger and method based on origami structure of the present invention achieves an organic unity of structural simplification and control reliability through innovative origami structure and air-rope hybrid drive mode, and has the following beneficial effects:

[0036] 1. This invention employs a triangular variant of the Yoshimura origami structure, with innovative improvements to this structure to serve as a joint module. Combined with airbags and cable drives, it achieves flexible bending, eliminating the complex integrated molding process of traditional soft grippers. Through detachable connectors, the joint module and finger segment module can be quickly reconfigured, allowing for flexible adjustment of the finger configuration according to the size and shape of different fruits, significantly reducing manufacturing and maintenance costs.

[0037] 2. This invention employs a layered control strategy of "pneumatic rapid envelopment + rope-driven event-driven". The airbag actuation utilizes the inherent flexibility of gas to achieve rapid, damage-free envelopment of the grasped object; through an innovative and improved origami structure, the bending angle of the joint module is maintained without external force, keeping the finger body bent inward to form the initial grasping configuration unchanged; the rope-driven mechanism, triggered by a thin-film pressure sensor, completes precise adaptive fitting using a "first-touch, first-stop, sequential locking" logic. The decoupled and synergistic operation of these three components ensures both the flexibility and accuracy of the grasp, while providing sufficient grasping force through rope actuation, overcoming the difficulty of balancing functional coupling, flexibility, accuracy, and grasping force in traditional soft grippers.

[0038] 3. The control logic of this invention is event-triggered, converting analog force signals into digital tactile event signals. It eliminates the need for complex force / position closed-loop algorithms, simplifying system debugging. The gripping force is maintained through open-loop control using preset cable displacement increments, independent of real-time sensor feedback. Even in the event of sensor failure, basic gripping functionality can still be maintained, significantly reducing on-site maintenance difficulty and technical requirements. This makes it particularly suitable for widespread application in complex environments such as agriculture. Attached Figure Description

[0039] Figure 1 This is a three-dimensional view of a flexible adaptive finger grasping mechanism based on origami structure, according to an embodiment of the present invention.

[0040] Figure 2 This is a perspective view of the finger seat according to an embodiment of the present invention;

[0041] Figure 3 This is an exploded view of the finger body according to an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram showing the connection between the first hollow body of the joint module and the airbag after deployment, according to an embodiment of the present invention.

[0043] Figure 5 This is a front view of the first hollow body of the joint module in an embodiment of the present invention after unfolding.

[0044] Figure 6 This is a schematic diagram of the origami structure in an embodiment of the present invention, showing the upper and lower triangles joined together to form a rhombus.

[0045] Figure 7 This is a cross-sectional view of the first hollow body and air bladder of the joint module according to an embodiment of the present invention;

[0046] Figure 8 This is a schematic diagram of the airbag in the assembly posture according to an embodiment of the present invention;

[0047] Figure 9 This is a perspective view of the finger segment connector according to an embodiment of the present invention;

[0048] Figure 10 This is a perspective view of the joint end connector according to an embodiment of the present invention;

[0049] in,

[0050] 1. Finger base, 2. Finger body, 3. Joint module, 31. Origami structure, 311. Pre-fold, 312. Original fold, 41. Root finger segment module, 42. Finger tip segment module, 5. Connector, 51. Finger segment end connector, 511. First boss, 512. External threaded post, 52. Joint end connector, 521. Second boss, 522. Internal threaded hole, 61. First rope, 62. Second rope, 7. Airbag, 71. Air passage, 72. Air passage channel, 81. First guide hole, 82. Second guide hole. Detailed Implementation

[0051] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. Certain embodiments of the invention will be described more fully below with reference to the accompanying drawings, and some, but not all, of these embodiments will be shown. In fact, various embodiments of the invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to enable the invention to meet applicable legal requirements.

[0052] In the description of this invention, it should be noted that the terms "inner," "outer," "upper," "lower," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0053] In this embodiment of the invention, a flexible adaptive finger grasping method based on origami structure is provided. Please refer to [reference needed]. Figures 1 to 10 As shown.

[0054] A flexible adaptive grasping finger based on origami structure includes a finger base 1 and three finger bodies 2 disposed on the finger base 1. The finger body 2 includes a joint module 3, a finger segment module (root finger segment module 41 and fingertip finger segment module 42), a connector 5 (finger segment end connector 51 and joint end connector 52), a first cable 61 and a second cable 62.

[0055] The finger base 1 and the three finger bodies 2 are arranged at equal intervals along the circumference, and a first guide hole 81 and a second guide hole 82 are opened at the connection positions of the finger base 1 and the three finger bodies 2.

[0056] The joint module 3 is configured as a first hollow body formed by the origami structure 31, with an airbag 7 on its back side and several first guide holes 81 on its ventral side. The first rope 61, the second rope 62, and the air passage 71 can pass through the space enclosed by the first hollow body.

[0057] The finger segment module is configured as a second hollow body and connected to the end of the joint module 3. The first cable 61, the second cable 62, and the air passage 71 pass through the space enclosed by the second hollow body.

[0058] The connector 5 is fixedly connected to the joint module 3 and the finger segment module respectively. A first guide hole 81 is opened on the ventral side of the connector 5, and a second guide hole 82 is opened in the middle position of the connector 5.

[0059] One end of the first cable 61 passes through several first guide holes 81 and connects to the ventral side of the last finger segment module (fingertip finger segment module 42). The other end of the first cable 61 is connected to the first cable drive mechanism. One end of the second cable 62 passes through several second guide holes 82 and connects to the middle position of the last finger segment module (fingertip finger segment module 42). The other end of the second cable 62 is connected to the second cable drive mechanism.

[0060] The first and second cable drive mechanisms are mounted on the finger seat 1 or on a support connected to the finger seat 1. In this embodiment, the first and second cable drive mechanisms have the same structure, including a servo motor and a rope wheel. The output shaft of the servo motor is connected to the rope wheel, and the other end of the first cable 61 / second cable 62 is connected to the rope wheel, with the first cable 61 / second cable 62 wound around the rope wheel. The servo motor drives the rope wheel to rotate forward to tighten the first cable 61 / second cable 62; the servo motor drives the rope wheel to rotate in the reverse direction to loosen the first cable 61 / second cable 62.

[0061] The airbag 7 is connected to the pneumatic mechanism via the air passage 71. The pneumatic mechanism includes an air source and a solenoid valve. The air source is connected to the air passage 71, and the solenoid valve is installed on the air passage 71.

[0062] When the pneumatic mechanism inflates the airbag 7 via the air passage 71, the dorsal side of the drive joint module 3 extends and the ventral side contracts, causing the finger body 2 to bend inward. When the first cable 61 is tightened by the first cable drive mechanism, the drive finger body 2 bends further inward or increases the preset tension displacement increment of the first cable 61. When the second cable 62 is tightened by the second cable drive mechanism, the drive finger body 2 returns to its original position.

[0063] The origami structure 31 is made of PVC and is a triangular variant of the Yoshimura origami structure. Pre-creases 311 are provided along the short diagonal of the rhombus formed by the joining of the upper and lower triangles. The pre-creases 311 correspond to... Figures 4 to 6The position of the dotted line in the text.

[0064] It should be noted that in the Yoshimura origami structure with its triangular variant, there is an original crease 312 between the upper and lower triangles. Specifically, the original crease 312 is located at the long diagonal of the rhombus formed by the joining of the upper and lower triangles. The original crease 312 corresponds to... Figures 4 to 6 The position of the dotted lines in the text.

[0065] After the airbag 7 inflates, the upper and lower triangles change from being folded relative to the original crease 312 to extending longitudinally; simultaneously, the left and right halves of the upper and lower triangles protrude outward relative to the pre-crease 311. By providing a pre-crease 311 at the short diagonal of the rhombus formed by the upper and lower triangles, the bending angle of the back side of the drive joint module 3 is increased. To achieve the same maximum bending angle, fewer origami layers are used, which improves the stability of the drive joint module 3. In addition, by providing a pre-crease 311 at the short diagonal of the rhombus formed by the upper and lower triangles, the bending angle of the back side of the drive joint module 3 can be maintained without external force, that is, the back side of the drive joint module 3 can maintain its original bending angle without external force. In this embodiment, if the airbag 7 is inflated and the air pressure of the airbag 7 decreases due to leakage in the air passage 71, the bending angle of the back side of the joint module 3 does not change, thereby maintaining the inward bending of the finger body 2 to form the initial grasping configuration, effectively improving the grasping accuracy of the finger body 2.

[0066] The orthographic projection of airbag 7 corresponds to the rhomboid region. Airbag 7 is connected to the rhomboid region and is a single-row series structure, sharing a common air passage 71. By matching airbag 7 with origami structure 31 in this way, the control of the bending angle movement of the dorsal side of joint module 3 can be made more precise when airbag 7 is inflated.

[0067] The inner and outer surfaces of the origami structure 31 are covered with a flexible layer. Specifically, from the outside in, a flexible layer, the origami structure 31, the air bladder 7, and another flexible layer are arranged in sequence. By setting the flexible layer, the flexible layer acts as a flexible hinge, allowing the origami structure 31 to fold or extend along the original crease 312 and the pre-crease 311.

[0068] The finger segment module includes a root finger segment module 41 and a fingertip finger segment module 42. The outer contours of both the root finger segment module 41 and the fingertip finger segment module 42 are frustoconical, and both are hollow silicone shell structures with a wall thickness of 5-6 mm. The second hollow body of the root finger segment module 41 is continuous from top to bottom, while the end of the second hollow body of the fingertip finger segment module 42 is closed.

[0069] The connector 5 includes a finger end connector 51 and a joint end connector 52. The detachable connection between the finger end connector 51 and the joint end connector 52 enables the connection between the joint module 3 and the finger module, allowing for arbitrary and rapid reconfiguration among several joint modules 3 and finger modules.

[0070] The back of the finger end connector 51 is provided with a first boss 511, which is used to connect with the inner wall of the second hollow body; the front of the finger end connector 51 is provided with an external thread post 512, which is used to connect with the internal thread hole 522 on the joint end connector 52.

[0071] The external threaded post 512 has a second guide hole 82 in the middle position, and an air passage 72 is opened on one side of the middle of the external threaded post 512. The air passage 72 is used for the air passage 71 to pass through.

[0072] The back of the joint end connector 52 is provided with a second protrusion 521, which is used to connect with the inner wall of the first hollow body; the front of the joint end connector 52 is provided with an internal threaded hole 522, which is used to connect with the external threaded post 512 on the finger end connector 51.

[0073] Several first grooves are formed at the contact positions between the first protrusion 511 and the inner wall of the second hollow body, so that the first grooves can hold adhesive when the first protrusion 511 and the inner wall of the second hollow body are bonded together, thereby ensuring a firm bond between the two. Several second grooves are formed at the contact positions between the second protrusion 521 and the inner wall of the first hollow body, so that the second grooves can hold adhesive when the second protrusion 521 and the inner wall of the first hollow body are bonded together, thereby ensuring a firm bond between the two.

[0074] The ventral side of the distal finger segment module (fingertip segment module 42) is covered with a silicone skin. A thin-film pressure sensor is attached to the inside of the silicone skin. The output of the thin-film pressure sensor is connected to a voltage comparator module, which converts the analog force signal into a digital tactile event signal. The voltage comparator module sets a reference voltage via a potentiometer to adjust the physical force threshold. When the force on the thin-film pressure sensor exceeds the threshold, the voltage comparator module outputs a high-low level transition, converting the analog force signal into a digital tactile event signal.

[0075] The voltage comparator module is connected to the controller via a signal cable, and the controller is connected to the control terminals of the first and second rope drive mechanisms via signal cables. The voltage comparator module uploads signals to the controller, which then triggers the first and second rope drive mechanisms to operate according to its control logic.

[0076] A flexible adaptive grasping method, applying the origami-structure-based flexible adaptive grasping finger described in this embodiment, is as follows:

[0077] S1, pneumatic rapid envelope;

[0078] Inflate the airbag 7 to the set pressure (e.g., 30 kPa). a Gas drives the dorsal extension and ventral contraction of joint module 3, causing finger 2 to bend inward, quickly forming an initial grasping configuration. At this time, the first cable 61 and the second cable 62 are completely released. Utilizing the high response speed and inherent compliance of pneumatic drive, a rapid "blind adaptation" envelope is achieved, ensuring that even if finger 2 collides with the grasped object, it will not cause damage to the object.

[0079] S2, rope-driven event-driven precision grasping;

[0080] The first cable drive mechanism gradually tightens the first cable 61, driving the finger 2 to bend further inward, and stops the tightening action of the first cable 61 corresponding to the finger 2 when it detects that the finger 2 is in contact with the grasping object.

[0081] Action: Maintain air pressure 7 in the airbag, and the servo motor of the first rope drive mechanism slowly retracts the rope from zero position at an extremely low speed (e.g., a few degrees per second).

[0082] Core logic – “first-to-stop, lock in sequence”:

[0083] After each step of rope winding, the controller polls and reads the comparator output signal corresponding to the thin-film pressure sensor on each finger 2.

[0084] If the output of the thin-film pressure sensor on a finger 2 is 0 (no contact), the servo motor corresponding to that finger 2 will continue to wind up the rope.

[0085] If the output of the thin-film pressure sensor on a finger 2 changes to 1 for the first time (indicating contact), the controller immediately records the current servo motor angle and stops the further rope winding action of that finger 2, locking the current servo motor.

[0086] Adaptive envelope: After the first finger 2 contacts and locks, the remaining fingers 2 continue to retract the rope until each finger 2 sequentially touches the grasped object and locks each servo motor. The entire process is driven entirely by the geometry of the grasped object, requiring no shape priors.

[0087] Phase termination: When all the thin-film pressure sensors of all fingers 2 are triggered and all fingers 2 are locked, the controller determines that the fingers have completed the full geometric envelope of the grasped object.

[0088] S3, constant deformation retention;

[0089] After all fingers 2 detect contact with the object being grasped, the preset tension displacement increment of the first rope 61 is uniformly increased to achieve open-loop control of the grasping force.

[0090] Action: After all finger bodies 2 are locked, the controller triggers the target position of the servo motor corresponding to the first cable 61 of all finger bodies 2 to uniformly increase by a preset small angle increment Δθ (such as 3°) based on the existing locked position, so that the first cable 61 increases the preset tension displacement increment.

[0091] Since finger 2 is already in contact with the object being grasped, this displacement increment cannot be realized and is instead converted into an increase in tension on the first cable 61, i.e., the grasping force F. The grasping force F has a linear relationship with Δθ: F = K Δθ, K is the overall stiffness of the system.

[0092] Force control: By presetting different Δθ values, the magnitude of the gripping force can be adjusted in an open-loop manner. This process does not rely on closed-loop feedback from a thin-film pressure sensor, embodying the design concept of "mechanical intelligence".

[0093] S4, finger repositioning;

[0094] The first cable drive mechanism releases the first cable 61, the airbag 7 deflates, and the second cable drive mechanism tightens the second cable 62, driving all finger bodies 2 to reset.

[0095] The present invention has been described in detail above with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the flexible adaptive gripping finger and method based on origami structure of the present invention. Of course, the specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flexible adaptive grasping finger based on origami structure, comprising a finger base and at least two finger bodies disposed on the finger base, characterized in that, The finger body includes: The joint module is configured as a first hollow body formed by a triangular variant Yoshimura origami structure. It has an air bladder on its back and several first guide holes on its ventral side. The air bladders are arranged in a single-row series structure, sharing a common air passage. The air bladders are connected to an air source via the air passage, and a solenoid valve is installed on the air passage. The long diagonal of the rhombus formed by the upper and lower triangles of the triangular variant Yoshimura origami structure is the original crease. Pre-creases are provided at the short diagonal of the rhombus formed by the upper and lower triangles of the triangular variant Yoshimura origami structure. The finger segment module is configured as a second hollow body and is connected to the end of the joint module; The connector is fixedly connected to the joint module and the finger segment module respectively. A first guide hole is opened on the ventral side of the connector, and a second guide hole is opened in the middle position of the connector. The first cable has one end passing through several first guide holes and connected to the ventral side of the last finger segment module, and the other end connected to the first cable drive mechanism. The second rope has one end passing through several second guide holes and connecting to the middle position of the last finger segment module, and the other end connecting to the second rope drive mechanism. When the air source inflates the airbag through the air passage, it drives the dorsal side of the joint module to extend and the ventral side to contract, causing the finger to bend inward. When the first rope is tightened by the first rope drive mechanism, the finger is driven to bend further inward or the preset tension displacement increment of the first rope is increased. When the second cable is tightened by the second cable drive mechanism, the finger body is driven to reset. After the airbag inflates, the upper and lower triangles change from being folded to extending longitudinally relative to the original crease; at the same time, the left and right halves of the upper and lower triangles protrude outward relative to the pre-crease; by providing a pre-crease at the short diagonal of the rhombus formed by the upper and lower triangles, the bending angle of the back side of the drive joint module is increased. When achieving the same maximum bending angle, fewer origami layers are used, which improves the stability of the drive joint module; by providing a pre-crease at the short diagonal of the rhombus formed by the upper and lower triangles, the bending angle of the back side of the drive joint module can be maintained without external force, that is, the back side of the drive joint module can maintain the original bending angle without external force.

2. The flexible adaptive grasping finger based on origami structure according to claim 1, characterized in that, The orthographic projection of the airbag corresponds to the rhomboid region, and the airbag is connected to the rhomboid region.

3. The flexible adaptive grasping finger based on origami structure according to claim 1, characterized in that, The inner and / or outer surfaces of the triangular variant Yoshimura origami structure are covered with a flexible layer.

4. The flexible adaptive grasping finger based on origami structure according to claim 1, characterized in that, The finger segment module includes a root finger segment module and a fingertip finger segment module, and the outer contour of the root finger segment module and / or the fingertip finger segment module is frustoconical.

5. A flexible adaptive grasping finger based on origami structure according to claim 1, characterized in that, The connector includes: The finger segment connector has a first protrusion on its back side for connecting with the inner wall of the second hollow body, and an external threaded post on its front side for connecting with the internal threaded hole on the joint end connector. The joint end connector has a second protrusion on its back for connecting with the inner wall of the first hollow body, and an internal threaded hole on its front for connecting with the external threaded post on the finger end connector.

6. A flexible adaptive grasping finger based on origami structure according to claim 1, characterized in that, The ventral side of the distal finger segment module is covered with a silicone skin, and a thin-film pressure sensor is attached to the inner side of the silicone skin. The output of the thin-film pressure sensor is connected to a voltage comparator module, which is used to convert the analog force signal into a digital tactile event signal.

7. A flexible adaptive grasping method, employing the flexible adaptive grasping finger based on origami structure as described in claim 6, characterized in that, The method process is as follows: S1, pneumatic rapid envelope; Inflate the airbag with gas, causing the fingers to bend inward to form an initial grasping configuration; S2, rope-driven event-driven precision grasping; The first cable drive mechanism gradually tightens the first cable, drives the finger to bend further inward, and stops the first cable tightening action of the corresponding finger when it detects that the finger is in contact with the grasping object. S3, constant deformation retention; After all fingers detect contact with the object being grasped, the preset tension displacement increment of the first rope is uniformly increased to achieve open-loop control of the grasping force. S4, finger repositioning; The first cable drive mechanism releases the first cable, the airbag deflates, and the second cable drive mechanism tightens the second cable, driving all fingers to reset.

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