Bionic finger and hand motion control device, bionic hand control method, robot

Abstract

The application discloses a bionic finger and hand movement control device, a bionic hand control method and a robot, and belongs to the technical field of bionic robots. The device comprises a plurality of flexible electric actuators, which comprise electric actuating materials capable of being actively deformed under electric field excitation. One end of the flexible electric actuator is connected to a finger adaptive base as a fixed end, and the other end is connected to a knuckle structure through a force transmission path as a free end. Each flexible electric actuator can be independently controlled, and the plurality of flexible electric actuators cooperatively drive the knuckle structure to generate bionic movement. A passive constraint structure is configured to provide anisotropic mechanical constraint for the active deformation of the flexible electric actuator, so as to guide and convert the active deformation into driving displacement or driving force along a first preset direction. A guide structure is used for guiding the deformation direction of the flexible electric actuator. The device can integrate strain, angle and tactile sensors, and realize closed-loop cooperative control through a controller.

Description

Technical Field

[0001] This application relates to the field of bionic robot technology, specifically to a bionic finger and hand motion control device, a bionic hand control method, and a robot. Background Technology

[0002] As a core component for human-computer interaction and the execution of fine motor skills, the anthropomorphism, dexterity, and compliantness of the robot's hand are key indicators for evaluating robot performance. Highly biomimetic hand movements not only enhance the adaptability of grasping and manipulation but also serve as an important vehicle for conveying robot intentions and achieving natural interaction.

[0003] Currently, the driving and transmission solutions for robotic hands mainly rely on actuators such as micromotors, pneumatic artificial muscles, or shape memory alloys, and transmit power through mechanisms such as gears, linkages, ropes, or rigid tendons. While these technologies can achieve basic grasping functions, they still have the following inherent limitations when applied to bionic hands that require high anthropomorphism and dexterity:

[0004] First, in terms of structural integration, traditional motors and complex rigid transmission chains are bulky and heavy, making it difficult to achieve a high-density distributed layout of multi-joint, multi-degree-of-freedom drive units within the limited palm space and narrow finger joints of a bionic hand. This often results in a clumsy hand with limited joint range of motion, making it difficult to replicate the compact anatomical structure and flexible range of motion of the human hand.

[0005] Secondly, in terms of motion performance, the motion output of rigid mechanisms is mostly discrete and step-like, lacking the continuous and compliant deformation characteristics unique to biological muscle and tendon systems. This makes grasping actions often appear stiff and abrupt, easily generating impact when contacting objects, and making it difficult to achieve a "balanced" adaptive grip and precise force control.

[0006] Furthermore, in terms of operational experience, the operation of motors and the meshing of gears inevitably produce audible noise and vibration, which can be quite disruptive in close-range service or human-robot collaboration scenarios. At the same time, traditional solutions have relatively high energy consumption, limiting the robot's battery life.

[0007] Furthermore, in the field of biomimetic intelligence, existing solutions mostly focus on position servo control, making it difficult to naturally reproduce the complex mechanical characteristics of multi-muscle group coordination and antagonism in human hand movements at the hardware level, such as the coordination of the superficial and deep flexor muscles of the fingers and the fine adjustment of intrinsic muscles in fine postures. This limits the ability of the hand to achieve rich, human-like gestures and compliant force interaction and fine manipulation capabilities based on proprioception.

[0008] Therefore, there is an urgent need in this field for a new driving and structural paradigm that can fundamentally overcome the defects of the aforementioned rigid systems and achieve a high degree of biomimicry from driving principles and structural forms to control strategies, so as to meet the urgent needs of the next generation of bionic robot hands for compactness, lightweight, compliant movement, quiet operation, and intelligent interaction. Summary of the Invention

[0009] To address the technical problems of existing robot hand drive solutions described in the background art, such as bulky structure, stiff movement, high noise and vibration, and lack of bionic coordination capabilities, this application provides a bionic finger and hand motion control device, a bionic hand control method, and a robot.

[0010] In a first aspect, this application provides a bionic finger motion control device for use in a robotic bionic finger, the robotic bionic finger including a finger adapter base whose shape is configured to match the contour of the mounting surface of a robotic palm or finger; and at least one phalanx structure; the bionic finger motion control device includes:

[0011] Multiple flexible electro-actuators, including an electro-actuating material capable of active deformation under electric field excitation, wherein one end of each flexible electro-actuator is fixed and connected to the finger adapter substrate, and the other end is free and connected to the knuckle structure through a force transmission path; wherein each flexible electro-actuator can be independently controlled, and the multiple flexible electro-actuators work together to drive the knuckle structure to produce biomimetic motion;

[0012] A passive constraint structure is configured to provide anisotropic mechanical constraints on the active deformation of the flexible electro-actuator, thereby guiding the active deformation and converting it into a driving displacement or driving force along a first preset direction.

[0013] A guide structure, disposed in the finger adapter base or the force transmission path, is used to guide the deformation direction of the flexible electro-actuator.

[0014] In one possible implementation, the flexible electro-actuator includes a driving layer, a first flexible electrode layer, and a second flexible electrode layer stacked together; the driving layer is made of the electro-actuating material; the first flexible electrode layer and the second flexible electrode layer are respectively disposed on both sides of the driving layer to apply a driving electric field; wherein, the passive constraint structure is coupled to the flexible electro-actuating material or the driving layer.

[0015] In one possible implementation, the passive constraint structure is a structure with anisotropic stiffness, the anisotropic stiffness structure comprising at least one of the following: a mesh structure constraint layer configured to have a low equivalent tensile stiffness in the preset direction; a sheet-like intrinsic anisotropic material layer; and discrete rigid constraint elements distributed along the preset direction.

[0016] In one possible implementation, the mesh structure constraint layer is a fiber reinforcement layer, in which high-strength fibers are arranged along a second preset direction.

[0017] In one possible implementation, the flexible electro-actuator includes one or more inner cores made of the electro-actuating material and a spiral or mesh flexible electrode layer surrounding the inner core; and the passive constraint structure includes a constraint guide sheath layer woven from high-strength fibers covering the outside of the flexible electro-actuator; wherein the flexible electro-actuator is linear and has a circular or elliptical cross-section.

[0018] In one possible implementation, the finger adapter base includes a multi-layered composite flexible base with an anchor point array and an insulating slot system corresponding to the finger bone on its inner side for fixing the fixed end of the flexible electro-actuator; a tendon channel and a guide ring simulating a human pulley structure are formed inside the base, and the tendon channel and the guide ring constitute the guide structure.

[0019] In one possible implementation, the plurality of flexible electroactors are configured to simulate the anatomical topology of the flexor and extensor muscles of the human hand, forming a flexor drive unit group and an extensor drive unit group. The free ends of the flexor drive unit group and the extensor drive unit group are respectively connected to different attachment positions of the phalanx structure through their respective force transmission paths to form a spatial antagonistic pair.

[0020] In one possible implementation, the flexor drive unit group includes drive units simulating the flexor digitorum profundus and flexor digitorum superficialis, the extensor drive unit group includes drive units simulating the central tendon bundle and lateral tendon bundle; and a miniature drive unit simulating the cochlear muscle for coordinating flexion-extension balance and lateral control.

[0021] In one possible implementation, the device further includes sensors integrated into the device, the sensors including at least one of the following: a strain sensor disposed on the flexible electro-actuator for detecting its deformation or output force; an angle sensor disposed at the joint of the knuckle structure for detecting the joint flexion / extension angle; and a tactile sensor array disposed in the fingertip or fingertip area of ​​the knuckle structure for detecting contact pressure and distribution.

[0022] In one possible implementation, the device further includes a controller electrically connected to the sensor and the flexible electro-actuator, for performing coordinated closed-loop control of the flexible electro-actuator based on the target motion command and sensor feedback signal, to achieve position control, force control or impedance control.

[0023] Secondly, this application provides a robot bionic hand motion control device including: a plurality of bionic finger motion control devices as provided in the first aspect, each corresponding to a plurality of fingers of the robot; and a hand-level collaborative controller for coordinating each finger to perform a target motion, the target motion including at least one of grasping, pinching, and multi-finger collaborative operation.

[0024] In one possible implementation, the hand-level collaborative controller is configured as follows:

[0025] The system receives task instructions; plans the motion trajectory and force distribution of each finger based on a pre-stored hand kinematics and dynamics model; generates coordinated control instructions for the driving devices of each finger and sends the coordinated control instructions to the driving devices of each finger to drive the bionic robotic hand to perform the operation corresponding to the task instructions; receives sensor feedback from each finger and adjusts the control instructions in real time based on the feedback to achieve overall coordination and stability control.

[0026] Thirdly, this application provides a bionic hand control method, applied to the bionic finger motion control device provided in the first aspect or the robot bionic hand motion control device provided in the second aspect, comprising the following steps: receiving motion commands; parsing the motion commands into collaborative drive signals for the plurality of flexible electro-actuators based on a pre-stored finger motion model or multi-finger collaborative model; outputting the drive signals to drive the knuckle structure to generate corresponding knuckle motion or hand collaborative operation, and being able to perform closed-loop adjustment based on sensor feedback.

[0027] Fourthly, this application provides a robot that integrates a bionic finger motion control device as provided in the first aspect, or a robot bionic hand motion control device as provided in the second aspect.

[0028] The bionic finger motion control device provided in this application embodiment applies an independently adjustable electric field excitation to multiple flexible electro-actuators, causing the electro-actuating material inside each flexible electro-actuator to undergo active deformation. This deformation is immediately subjected to anisotropic mechanical constraints imposed by the passive constraint structure, preventing it from developing freely and instead forcibly guided and converted into a single driving displacement or driving force along a first preset direction. This oriented mechanical output is then efficiently and accurately transmitted to the knuckle structure through a force transmission path defined and stabilized by the guiding structure, thereby driving it to produce precise movement. By coordinating and controlling the excitation of each actuator, the desired bionic motion is ultimately achieved. Through the oriented transformation of deformation by the passive constraint structure and the stable guidance of the transmission path by the guiding structure, the mapping relationship between electrical signals and mechanical motion is solidified at the physical level, enabling the independent electrical control of multiple electro-actuators to be directly, efficiently, and reliably converted into precise knuckle movement. This achieves multi-degree-of-freedom distributed actuation within a limited space, while also possessing high control precision, high response speed, and high energy utilization efficiency. Attached Figure Description

[0029] Figure 1 A schematic diagram of the structure of a bionic finger motion control device provided in one embodiment of this application;

[0030] Figure 2 This is a schematic diagram of the connection and installation of a bionic finger provided in one embodiment of this application;

[0031] Figure 3 This is a schematic diagram of the connection structure of a bionic finger motion control device provided in one embodiment of this application;

[0032] Figure 4 A schematic diagram of the drive connection of a bionic finger provided in one embodiment of this application;

[0033] Figure 5 This is a schematic diagram of the layered structure of a flexible electric actuator provided in one embodiment of this application;

[0034] Figure 6 A schematic diagram of the structure of a robot bionic hand motion control device provided in one embodiment of this application;

[0035] Figure 7 This is a flowchart illustrating a bionic hand control method provided in one embodiment of this application. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are only used to illustrate this application and are not intended to limit the scope of protection of this application.

[0037] Figure 1 This is a schematic diagram of the structure of a bionic finger motion control device provided in one embodiment of this application.

[0038] In some embodiments, the bionic finger motion control device 10 can be applied to a robotic bionic finger, which includes a finger adapter base whose shape is configured to match the profile of the mounting surface of a robotic palm or finger; and at least one knuckle structure.

[0039] Reference Figure 1 As shown, the bionic finger motion control device 10 may include:

[0040] Multiple flexible electric actuators 101 may specifically include, for example: Figure 1 The flexible electro-actuators 1 to n shown are provided, wherein the number n of flexible electro-actuators can be set based on application requirements, and this application does not limit the number n. The flexible electro-actuator 101 may include an electro-actuating material capable of active deformation under electric field excitation, and one end of the flexible electro-actuator 101 is connected to the finger adapter substrate as a fixed end, while the other end is connected to the knuckle structure as a free end through a force transmission path; each flexible electro-actuator can be independently controlled, and multiple flexible electro-actuators work together to drive the knuckle structure to produce biomimetic motion.

[0041] The passive constraint structure 102 is configured to provide anisotropic mechanical constraints on the active deformation of the flexible electric actuator, thereby guiding the active deformation and converting it into a driving displacement or driving force along a first preset direction.

[0042] The guide structure 103 is disposed in the finger adapter substrate or force transmission path to guide the deformation direction of the flexible electro-actuator.

[0043] based on Figure 1The bionic finger motion control device provided in the illustrated embodiment, when an independently adjustable electric field excitation is applied to each flexible electro-actuator in the device, causes the electro-actuating material inside each flexible electro-actuator to undergo active deformation. This deformation is immediately subjected to anisotropic mechanical constraints applied by a passive constraint structure, preventing it from freely expanding or contracting. Instead, it is forcibly guided and converted into a single driving displacement or driving force along a first preset direction. This directional mechanical output acts directly on the knuckle structure through a force transmission path (whose direction is defined and stabilized by a guide structure), thereby driving it to produce precise linear displacement or rotation. By independently and collaboratively controlling the intensity and timing of the electric field applied to each flexible electro-actuator by an external system, different driving output modes can be combined, ultimately resulting in bionic movements such as bending, stretching, or combinations thereof, expressed through the knuckle structure. Based on the passive constraint structure and guide structure in this bionic finger motion control device, the mapping relationship between deformation and output is solidified at the mechanical and physical level, enabling the applied electric field signal to be efficiently, reliably, and directly converted into precise mechanical motion. This achieves high motion fidelity under open-loop control while eliminating the need for complex sensing and closed-loop feedback components within the device, resulting in an extremely compact, reliable structure with lower manufacturing costs. By employing a distributed flexible electro-actuator as the drive source, combined with a passive constraint structure that guides and transforms its deformation, and a guiding structure that ensures efficient force transmission, the device simultaneously solves the technical problems of traditional bionic hands in terms of structural integration, motion performance, user experience, and bionic intelligence at the hardware level. Correspondingly, it achieves a compact, lightweight multi-degree-of-freedom layout, outputs continuous, compliant, and controllable mechanical properties, improves low noise, low vibration, and high energy efficiency, and provides a physical basis for reproducing complex control involving the coordination and antagonism of multiple muscle groups.

[0044] Figure 2 This is a schematic diagram of the connection and installation of a bionic finger provided in one embodiment of this application.

[0045] Reference Figure 2 As shown, the robotic bionic finger can be connected to a target location, such as the target finger location on the palm, via a finger adapter base D1. For example, when... Figure 2 The robot's bionic finger shown is the index finger, which can be connected to the index finger position of the robot's bionic hand via its finger adapter base D1.

[0046] In one implementation, reference is made to Figure 2 As shown, the fixed end of the flexible electric actuator 101 can be adapted to the base D1 by a finger, and the free end of the flexible electric actuator 101 is connected to the knuckle structure D2 through a force transmission path.

[0047] It should be noted that, Figure 2The connection position between the free end of the flexible electro-actuator 101 and the knuckle structure D2 can be distinguished based on different requirements of finger driving mode, finger movement function and other extended functions. In other words, the connection position between the free end of the flexible electro-actuator 101 and the knuckle structure D2 can be adjusted according to requirements so that the physical structure can provide physical and mechanical support for the corresponding requirements.

[0048] In some embodiments, the finger adapter base includes a multi-layered composite flexible base with an anchor point array and an insulating slot system corresponding to the finger bone on its inner side for fixing the fixed end of the flexible electro-actuator; a tendon channel and a guide ring simulating the human body pulley structure are formed inside the base, and the tendon channel and the guide ring constitute a guide structure.

[0049] Figure 3 This is a schematic diagram of the connection structure of a bionic finger motion control device provided in one embodiment of this application.

[0050] Reference Figure 3 As shown, in one embodiment, the fixed ends N1 of multiple flexible electro-actuators 101 can be precisely positioned and fixed in the insulating slots M1 of the anchor point array. A tendon channel 103a and a guide ring 103b simulating a human pulley structure are formed inside the substrate. The tendon channel 103a and the guide ring 103b constitute a guide structure 103. When the multiple flexible electro-actuators 101 are independently excited and generate active deformation, the displacement or force generated at their free ends is guided as a "tendon" into the pre-fabricated tendon channel 103a inside the substrate. This force transmission path is then constrained and steered by the guide ring 103b simulating a human pulley structure, thereby precisely transmitting the drive output to the target phalanx structure in a low-friction, high-efficiency manner, driving it to generate the expected biomimetic movement. The high integration of the integrally formed internal guiding network (tendon channel 103a and guide ring 103b) and the external fixing interface (anchor point array and insulating slot M1) not only achieves stable, insulated and reconfigurable distributed fixing of multiple flexible electric actuators 101, but also ensures the high efficiency and directional accuracy of drive energy transmission through the biomimetic optimized force transmission path. At the same time, the flexibility of the substrate itself gives the entire device better fit with the mounting surface and shock resistance.

[0051] Reference Figure 3 As shown, in one embodiment, the free end of the flexible electro-actuator 101 can also be connected to the knuckle structure via a knuckle joint adapter V1. The shape of the knuckle joint adapter V1 varies for different fingers (thumb, index finger, middle finger, ring finger, and little finger), and its function is to enable the flexible electro-actuator 101 to connect to the knuckle structure in a more biomimetic tendon manner.

[0052] Figure 4This is a schematic diagram of the drive connection of a bionic finger provided in one embodiment of this application.

[0053] Reference Figure 4 As shown, each bionic finger can be... Figure 1 The bionic finger motion control device provided in the illustrated embodiment is used for drive control, and the connection structure of the bionic finger motion control device can be as follows: Figure 3 As shown, and then through Figure 2 The installation method shown connects and installs the device to the corresponding position on the bionic hand to form a complete bionic hand.

[0054] Figure 5 This is a schematic diagram of the layered structure of a flexible electric actuator provided in one embodiment of this application.

[0055] Reference Figure 5 As shown, in some embodiments, the flexible electric actuator includes a driving layer 50a, a first flexible electrode layer 50b, and a second flexible electrode layer 50c stacked together. The first flexible electrode layer and the second flexible electrode layer are respectively disposed on both sides of the driving layer to apply a driving electric field.

[0056] In one embodiment, the driving layer is made of an electro-actuating material, specifically a flexible electro-actuating material.

[0057] In one embodiment, the passive constraint structure is coupled to the flexible electric actuator or driving layer in the same or similar way, and the specific coupling method is as follows:

[0058] I. Embedded or composite coupling

[0059] In current coupling structures, the passive constraint structure and the corresponding materials of the driving layer (or flexible electro-actuator) are interwoven or composited during manufacturing to form a functional whole. For example, this could be a fiber-reinforced / woven constraint layer, specifically, high-strength, low-elongation fibers (such as carbon fiber, Kevlar fiber, or metal wire) can be embedded or woven along a specific direction (non-isotropic) on or inside the surface of a sheet-like or columnar dielectric elastomer (driving layer). These fiber networks constitute the passive constraint structure.

[0060] In the current coupling structure, when a flexible electro-actuator attempts to expand uniformly within a plane under electric field excitation, the fiber network, due to its specific orientation, only allows for significant strain along the direction perpendicular to the fibers. This transforms the two-dimensional planar expansion into a significant contraction or bending in a single direction. The direction of deformation output can be controlled by pre-setting the fiber arrangement pattern (e.g., unidirectional, double-helix, radial). The passive constraint structure and the driving layer (or flexible electro-actuator) are integrated at the microscopic level, with no relative sliding, direct energy transfer, and the ability to achieve rapid and precise directional deformation output.

[0061] II. Laminated or assembled coupling

[0062] In the current coupling structure, the layered passive constraint structure and the driving layer are physically bonded together as independent thin layers to work together. For example, this laminated structure can be an asymmetric laminated structure, in which a flexible thin sheet with asymmetric mechanical properties is bonded as a constraint layer to one or both sides of the driving layer (such as a dielectric elastomer film). For example, one side is bonded with a thin sheet with low elongation but flexibility (such as polyimide), while the other side remains free or is bonded with an elastomer.

[0063] In the current coupled structure, when a flexible electro-actuator is excited by an electric field, the driving layer attempts to expand. The extendable side deforms freely, while the non-extendable side (constraint layer) greatly restricts strain in that direction, causing the entire structure to only curl or bend towards the free side. The constraint layer and the driving layer are tightly "coupled" through adhesives or physical clamping, jointly determining the deformation mode. Efficient bending actuation can be easily achieved by using constraint layers of different stiffness on one or both sides of the electro-actuator.

[0064] III. Shell or Frame-Type Coupling

[0065] In the current coupling structure, the passive constraint structure acts as a prefabricated shell or skeleton with a specific geometry, encapsulating or embedding the driving layer within it. For example, it can be a flexible shell with a pre-defined deformable cavity; specifically, the driving layer is wrapped in a flexible shell cast from silicone or polymer. The shell's wall thickness is non-uniform, or its interior is designed with reinforcing ribs and cavities with specific orientations.

[0066] In the current coupling structure, when the driving layer expands, its deformation is mechanically constrained by the shape of the outer shell. The direction where the walls are thin or the cavity is located is more prone to expansion deformation, thus being "guided" to the predetermined deformation direction. The outer shell itself is a passive constraint structure, "coupled" to the driving layer through interference fit or bonding. This shell not only provides constraint but also protects the brittle electrodes and electro-actuated materials from physical damage and environmental influences.

[0067] IV. Integrated Topological Coupling

[0068] In current coupled structures, the boundary between the passive constraint structure and the driving layer merges at the material or structural topology level. For example, a component can be fabricated using 3D printing or multimaterial forming techniques, where the material stiffness or microstructure exhibits spatial gradient variations or anisotropic distribution. The softer regions act as the "driving region," while the harder regions or those with specific oriented microstructures act as the "constraint region."

[0069] In the current coupled structure, when a flexible electro-actuator responds holistically to an electric field, the active deformation of the "driving region" is directly limited by the mechanical properties of the materials in the adjacent "constraint regions," resulting in directional macroscopic deformation. Constraint and driving are integrally coupled in terms of materials and structure, and cannot be physically separated. This allows for the design of regions with continuously varying stiffness, achieving smoother, more natural deformations that more closely resemble those of biological tissues.

[0070] In some embodiments, the passive constraint structure is a structure with anisotropic stiffness for achieving anisotropic mechanical constraints. The anisotropic stiffness structure includes at least one of the following: a mesh structure constraint layer configured to have a low equivalent tensile stiffness in the preset direction; a sheet-like intrinsically anisotropic material layer; and discrete rigid constraint elements distributed along the preset direction.

[0071] In one embodiment, anisotropic mechanical constraints can be achieved by composite materials, such as directional embedding of high-modulus fibers or films in a flexible matrix, to form a laminated structure that is difficult to stretch in a specific direction but easy to deform in the vertical direction.

[0072] In another embodiment, microstructural design, such as machining periodically arranged corrugations, grooves, or honeycomb-like holes into the material, can be used to make it exhibit distinctly different resistance to deformation in different directions, thus achieving anisotropic mechanical constraints. Other shapes are also possible in other embodiments, and this application does not limit the shape.

[0073] In another implementation, anisotropic mechanical constraints can be achieved by directly constructing a mechanical device that allows movement in a specific direction while restricting movement in other directions through macroscopic mechanical structures such as hinges, flexible joints, or asymmetric grid frames.

[0074] The anisotropic mechanical constraints provided by the structures with anisotropic stiffness in the above-described embodiments can directly determine whether the final output is linear force, torque or bending force, thereby replacing complex multi-motor coordination or precise motion control algorithms in a simple and reliable purely mechanical way.

[0075] In some embodiments, the structure having anisotropic stiffness is a constraint layer having a mesh structure; the constraint layer with mesh structure is configured such that the equivalent tensile stiffness of the constraint layer in a first predetermined direction is lower than its equivalent tensile stiffness in at least one other direction, thereby achieving anisotropic mechanical constraint.

[0076] The constraint layer with a mesh structure achieves anisotropic stiffness through its specific geometric design: for example, its mesh units (such as holes) are arranged in slender elliptical or strip-shaped patterns along a first predetermined direction, or sparser rod connections are designed in this direction. This allows the mesh to easily extend through rod bending or hole deformation when the constraint layer is under stress along the first predetermined direction, exhibiting lower equivalent tensile stiffness; while in other directions perpendicular to or at a certain angle, the mesh is difficult to stretch due to structural continuity or dense rods, thus exhibiting higher equivalent tensile stiffness. This anisotropic constraint, achievable with a single material structure and with a precisely designed stiffness ratio, not only eliminates the risk of interface failure in traditional multilayer composite materials, but also allows the mechanical guiding characteristics of the driving unit to be flexibly "programmed" by adjusting the mesh pattern, thereby achieving lightweight, high air permeability, and better in-plane compliance while ensuring excellent constraint effects.

[0077] In some embodiments, the structure having anisotropic stiffness is made of a single intrinsically anisotropic material, wherein the Young's modulus of the intrinsically anisotropic material in a first predetermined direction is lower than its Young's modulus in at least one other direction.

[0078] In this passive constraint structure, when the passive constraint structure is composed of a single, uniform sheet of intrinsically anisotropic material, its anisotropic stiffness originates from the inherent molecular orientation or oriented crystal structure within the material. For example, this can be achieved using a polymer film or a specifically oriented liquid crystal elastomer film produced by a uniaxial stretching process. The mechanism for achieving anisotropic constraint lies in the fact that the material has a lower Young's modulus in a first predetermined direction, making it easily stretchable or compressible in that direction; while in at least one other direction perpendicular to it or at a specific angle, it has a significantly higher Young's modulus, thus rigidly suppressing deformation. This intrinsic difference in modulus allows the constraint layer to "allow" a certain degree of coordinated deformation along the low-modulus direction when the driving layer attempts to expand, while "forcibly" preventing deformation in the high-modulus direction, thereby guiding the output of the driving layer to the first predetermined direction. Because the anisotropy is provided by the intrinsic properties of the material, this method eliminates the need for composite, lamination, or complex microstructure processing, completely eliminating the risk of interface failure between multilayer materials and ensuring high uniformity and long-term stability of the constraint performance. This design makes the drive unit structure extremely compact, robust, and consistent, making it particularly suitable for applications with extremely high requirements for reliability, lightweight, and miniaturization.

[0079] In some embodiments, a structure with anisotropic stiffness includes a plurality of discrete rigid constraint elements, which are distributed in a chain or strip shape along a first predetermined direction, thereby forming a continuous constraint path in a direction perpendicular to the first predetermined direction.

[0080] This structure achieves anisotropic constraints by flexibly connecting multiple discrete rigid constraint elements (such as miniature rigid plates or short rods) in a chain-like or strip-like manner along a first predetermined direction (e.g., via hinges or a flexible substrate). When the driving layer deforms, the structure can bend or stretch like a chain in the first predetermined direction, exhibiting low equivalent stiffness; while perpendicular to the first predetermined direction, these discrete elements, due to their own rigidity and continuous arrangement, collectively form a nearly immeasurable robust "constraint wall," strongly suppressing deformation. This design cleverly combines local flexibility with overall rigidity, ensuring that the driving unit can freely output motion or adapt to complex curved surface installations in specific directions, while also ensuring high reliability and stability in key constraint directions. Thus, while achieving efficient mechanical guidance, it improves the geometric adaptability and structural durability of the driving unit for complex application scenarios.

[0081] In some embodiments, the mesh structure constraint layer can be a fiber reinforcement layer, wherein the high-strength fibers in the fiber reinforcement layer are arranged along a second predetermined direction, and the angle between the fiber arrangement direction and the first predetermined direction is less than a preset angle. For example, the preset angle may include 45 degrees. In other embodiments, the preset angle may also be other angle values, which are not limited in this application.

[0082] The design achieves constraint guidance by incorporating a fiber reinforcement layer on the flexible electrode layer: high-strength fibers (such as carbon fiber, aramid, or glass fiber filaments) are embedded or adhered to the surface of the flexible electrode layer (first and second flexible electrode layers) at an angle of less than 45 degrees along a second predetermined direction. When the angle between the high-strength fiber arrangement direction and the "first predetermined direction" requiring driving force is small, the fiber bundle can enhance the tensile stiffness of the composite structure perpendicular to the fiber arrangement direction, thereby effectively suppressing the expansion deformation of the driving layer in this direction. Simultaneously, due to the relative sliding or bending of the fibers along the fiber arrangement direction, a low stiffness is maintained, allowing motion to be released along this "first predetermined direction." This design enables the flexible electrode layer to maintain its conductivity while possessing the mechanical properties of directional constraint. It not only achieves high structural integration and lightweighting but also enables precise and customizable design of the magnitude and direction of constraint stiffness through a simple and reliable fiber arrangement process, thereby ensuring more efficient and controllable driving output.

[0083] In some embodiments, the flexible electro-actuator includes one or more inner cores made of electro-actuating material and a spiral or mesh flexible electrode layer surrounding the inner core; and a passive constraint structure includes a constraint guide sheath layer woven from high-strength fibers covering the outside of the flexible electro-actuator; wherein the flexible electro-actuator is linear and has a circular or elliptical cross-section.

[0084] When the spiral or mesh-like flexible electrode layer is energized, an electric field is generated within it. This electric field directly excites the inner core, made of electro-actuating material, to undergo active deformation (such as axial contraction or radial expansion). At this time, the high-strength fiber-woven constraint guide sheath layer tightly wrapped on the outside immediately comes into play. Its specific weaving angle and topology rigidly restrict the radial expansion of the electro-actuator, while guiding the deformation energy of the inner core to be almost completely converted into a strong contraction or elongation along the axis of the electro-actuator (the first preset direction), thereby outputting a purely linear driving displacement or driving force. This linear output can be directly used as a highly efficient "artificial tendon" to pull or push the phalanx structure. Based on the above-mentioned linear flexible actuator, its linear, small-section shape allows it to be flexibly deployed and highly integrated within the narrow internal space of the bionic finger, much like a biological tendon, greatly improving the structural compactness. Secondly, the integrated design of the constraint guide sheath and the flexible electro-actuator not only efficiently and with low loss converts the multidimensional deformation of the material into a single axial output, significantly improving energy utilization efficiency and drive stroke, but its robust fiber braided structure also serves as a physical protective layer, significantly enhancing the durability and overload resistance of the flexible electro-actuator. This structure makes it possible to construct a high-strength, high-response, and high-reliability distributed tendon actuation system.

[0085] In some embodiments, a plurality of flexible electro-actuators are configured to simulate the anatomical topology of the flexor and extensor muscles of the human hand, forming a flexor drive unit group and an extensor drive unit group. The free ends of the flexor drive unit group and the extensor drive unit group are respectively connected to different attachment positions of the phalanx structure through their respective force transmission paths to form a spatial antagonistic pair.

[0086] In one embodiment, the simulated anatomical topology of the flexor and extensor muscles of the human hand is represented as follows: multiple flexible electroacters of the flexor drive unit group are spatially distributed along the palmar side of the phalanx (i.e., the side facing the palm), with their overall direction parallel to the phalanges, and simulate the relationship between the superficial and deep flexor digitorum muscles in a layered or series configuration; while multiple flexible electroacters of the extensor drive unit group are correspondingly distributed along the dorsal side of the phalanx. These two sets of drive units are not simply opposite each other, but are arranged asymmetrically and spatially interlaced according to the joint rotation center, so that their "force lines" form an effective force couple at the joint. Their free ends (i.e., output ends) are anchored to specific attachment positions on the phalanx structure through high-strength wires or flexible bands (force transmission paths), calculated biomechanically. For example, the flexor units are connected to the base on the palmar side of the distal phalanx, and the extensor units are connected to the base on the dorsal side of the middle phalanx, thus forming one or more spatial antagonistic pairs in three-dimensional space.

[0087] The process of achieving flexible actuation based on this structure is as follows: When it is necessary to drive the finger to bend, an excitation electric field can be applied independently to one or more electroactors in the flexor muscle actuation unit group, causing the internal electroacting material to undergo active contraction deformation; this contraction force applies a pulling force to the palmar attachment point of the phalanx structure through its force transmission path, generating a torque that causes the joint to rotate around the axis.

[0088] While driving finger flexion, the extensor drive unit group can be in the following three states to achieve fine control:

[0089] 1. Passive relaxation, acting only as an elastic load, providing a compliant reset similar to that of organisms.

[0090] 2. Apply partial excitation to provide adjustable antagonistic stiffness to achieve "rigid" grip.

[0091] 3. When the material possesses bidirectional driving characteristics, a reverse excitation can be applied to cause it to actively elongate, synergistically accelerating bending or achieving hyperflexion. Conversely, when finger extension is required, the extensor muscle units are stimulated, and the flexor muscle units are placed in the aforementioned controllable state.

[0092] The passive constraint structure, specifically a fiber-woven sheath integrated on the outside of each electro-actuator, ensures that the deformation of each flexible electro-actuator is efficiently converted into axial tension, while the guiding structure guarantees the stability of the force transmission path. By independently, collaboratively, and sequentially controlling the excitation signals of each actuator within these two sets of units (flexor drive unit group and extensor drive unit group), a variety of continuous, compliant, and stiffness-adjustable biomimetic movements, from rapid fist clenching to gentle pinching, can be reproduced.

[0093] Based on the above structure, multiple flexible electric actuators directly replicate the antagonistic distribution principle of human hand muscles at the hardware topology level, thus solving the problem of achieving the essential biomimetic motion characteristics that are difficult to achieve with traditional actuators. Specifically:

[0094] In the first aspect, the two sets of drive units (flexor drive unit group and extensor drive unit group) are physically independent and functionally antagonistic. The control system can achieve active flexion and active extension of the joint by independently adjusting the electrical excitation applied to the two sets of units, and achieve continuous variable stiffness adjustment of the joint from soft to rigid by applying different proportions of excitation at the same time, thereby replicating the core characteristics of biological joints at the hardware level.

[0095] Secondly, when one or more electric actuators in the drive unit group fail for some reason, the other normally functioning electric actuators in the same group can still work together to output part of the driving force to maintain the basic movement function of the joint, thereby significantly improving the reliability of the entire finger drive system.

[0096] Thirdly, since the physical layout of the hardware is highly consistent with the topological relationship of biological muscles, when developing control algorithms, human motion control models and physiological knowledge (such as the principle of muscle group synergistic activation) can be directly referenced or mapped, which greatly reduces the difficulty of software modeling and control programming for achieving complex and compliant biomimetic motion.

[0097] Fourthly, the distributed layout avoids the concentration of driving torque in a single location, making the force more balanced; the transmission path of the linear actuator and the tendon-like structure allows the drive unit to be flexibly arranged in the non-core area of ​​the finger, thus achieving powerful driving force while ensuring the slenderness and naturalness of the overall finger contour, and making the movement more agile.

[0098] In some embodiments, the flexor drive unit group includes drive units simulating the flexor digitorum profundus and flexor digitorum superficialis, the extensor drive unit group includes drive units simulating the central tendon bundle and lateral tendon bundle; and a miniature drive unit simulating the cochlear muscle, for coordinating flexion-extension balance and lateral control.

[0099] In one implementation, a driving unit simulating the flexor digitorum profundus has a force transmission path spanning multiple phalanges, primarily driving the fingertips to generate a strong grip. A unit simulating the flexor digitorum superficialis mainly acts on the proximal phalanges, achieving basic finger flexion. Extensor units simulating the central and lateral tendon bundles are responsible not only for dorsiflexion of the phalanges but also for lateral movement and fine-tuning of the fingers through asymmetrical force distribution. A miniature driving unit simulating the cochlear muscle is embedded between the flexor and extensor units, using its subtle contractions to regulate the tension of the flexor tendons, coordinating the balance of the flexor and extensor muscle groups in real time, and assisting in achieving fine lateral control such as finger adduction and abduction. This entire topology directly replicates the complex anatomical relationship of the intrinsic and extrinsic muscles of the human hand working together at the hardware level, enabling a single finger to independently and precisely perform a full range of biomimetic movements, from strong grip to fine pinching, from planar extension to dexterous lateral movement, while significantly reducing the algorithmic modeling difficulty for achieving such complex multi-degree-of-freedom coordinated control.

[0100] Based on the structure of the flexor drive unit group and the extensor drive unit group mentioned above, a bionic index finger is pre-designed, which includes three phalanges: proximal phalanx P1, middle phalanx P2 and distal phalanx P3, as well as the corresponding joints: metacarpophalangeal joint (MCP), proximal interphalangeal joint (PIP) and distal interphalangeal joint (DIP).

[0101] In this bionic index finger, the drive system is configured according to the aforementioned bionic topology:

[0102] The actuation unit simulating the flexor digitorum profundus muscle is configured as follows: a first linear flexible electro-actuator is used, with its fixed end anchored to the proximal end of the palmar base and its free end connected to a high-strength fibrous tendon T1 serving as a force transmission path. The course of this high-strength fibrous tendon T1 is constrained and guided by pre-fabricated guiding structures (such as tendon channels and guide rings) within the finger-adaptive base and phalanx structure, allowing it to pass sequentially through the metacarpophalangeal joint and proximal interphalangeal joint regions, ultimately anchoring to the palmar base of the distal phalanx P3. When the first linear flexible electro-actuator is energized and generates axial contraction, its output mechanical tension is directly and efficiently transmitted to the distal phalanx through the high-strength fibrous tendon T1, thereby simultaneously driving the proximal and distal interphalangeal joints to flex, achieving a powerful fingertip grip that simulates the function of the flexor digitorum profundus muscle.

[0103] The actuation unit simulating the flexor digitorum superficialis muscle is configured as follows: a second linear flexible electro-actuator is used, with its fixed end anchored at a corresponding position on the base of the palm, and its free end connected to a high-strength fibrous tendon T2, which serves as another independent force transmission path. The course of this high-strength fibrous tendon T2 is also preset and guided by the system's guide structure, ensuring that after passing through the metacarpophalangeal joint area, it is precisely anchored to the palmar side of the middle phalanx P2. When the second linear flexible electro-actuator is independently excited and generates axial contraction, its output mechanical force is directly transmitted through the high-strength fibrous tendon T2 and mainly acts on the middle phalanx P2, thereby driving the proximal interphalangeal joint to flex, realizing the basic flexion movement of the middle segment of the finger. This movement constitutes an important component of bionic grasping.

[0104] The extensor unit group simulating the central and lateral tendon bundles is configured to include two drive units: a drive unit E1 simulating the central tendon bundle and a drive unit E2 simulating the lateral tendon bundles. The drive unit E1 simulating the central tendon bundle employs a linear flexible electro-actuator, whose free end is connected to a pre-set central anchor point (simulating the extensor tendon extension) on the dorsal side of the middle phalanx P2 and the distal phalanx P3 via a high-strength fibrous tendon T3, which serves as the central force transmission path. The drive unit E2 simulating the lateral tendon bundles employs two small linear electro-actuators E2a and E2b arranged in parallel in space. Their free ends are connected to pre-set radial and ulnar anchor points on the dorsal side of the middle phalanx P2 and the distal phalanx P3, respectively, via tendons T4a and T4b, which serve as lateral force transmission paths, under the guidance of a guide structure. When the driving unit E1 simulating the central tendon bundle is excited, the contractile force it generates is transmitted through the high-strength fibrous tendon T3 in the central force transmission path, mainly driving the proximal and distal interphalangeal joints to perform dorsiflexion movements. When the small linear electro-actuators E2a and E2b of the driving unit E2 simulating the lateral tendon bundle are controlled independently, for example, only the small linear electro-actuator E2a corresponding to the radial side is excited, then the tendon T4a in the lateral force transmission path generates an asymmetrical tension, causing the finger to rotate slightly around the longitudinal axis (such as radial deviation), thereby achieving fine lateral postural adjustments.

[0105] The miniature actuation unit simulating the cochlear muscle is configured to employ two miniature linear flexible electro-actuators (specifically, miniature linear flexible electro-actuators L1 and L2), which can be distributedly embedded in the base of the palm, positioned corresponding to the anatomical key points through which the flexor tendon paths emerge. The free ends of the two miniature linear flexible electro-actuators are respectively connected to microfiber tendons T5 and T6, serving as finely adjustable force transmission paths; the ends of these microfiber tendons are connected at specific angles to pre-set force coupling points on the main tendon path T7 of the actuation unit simulating the flexor digitorum profundus and the main tendon path T8 of the actuation unit simulating the flexor digitorum superficialis (or, in another embodiment, directly acting on guide structures pre-set in the tendon paths, such as bionic pulleys). When fine motor coordination is required, such as stabilizing the fingertips and adjusting joint stiffness during pinching, the control system can independently and precisely stimulate the actuation units simulating the flexor digitorum profundus and / or the actuation units simulating the flexor digitorum superficialis. The micro-contraction of the simulated flexor digitorum profundus drive unit applies a lateral preload to the main tendon path T7 of the simulated flexor digitorum profundus drive unit via the microfiber tendon T5, thereby adjusting the overall tension and dynamic response of the flexor digitorum profundus path without significantly driving joint movement. A micro-linear flexible electro-actuator L2 performs similar adjustments to the main tendon path T8 of the simulated flexor digitorum superficialis drive unit, which will not be described further. Through the independent micro-adjustment of the two main flexor tendons by the simulated flexor digitorum profundus and flexor digitorum superficialis drive units, the system can dynamically coordinate the force balance between flexor groups F1 and F2 and extensor groups E3 and E4 in real time, optimizing the net stiffness and stability of the joint, and assisting in achieving the adduction or abduction micro-adjustments required for fine finger manipulation.

[0106] When a strong fist-clenching action is required, the control system simultaneously applies a high-intensity excitation electric field to the driving units simulating the flexor digitorum profundus and the flexor digitorum superficialis. The driving units simulating the flexor digitorum profundus and the flexor digitorum superficialis generate significant axial contractions, applying concentrated tension to the palmar side of the distal phalanx P3 and the middle phalanx P2 through their respective tendon pathways that cross multiple phalanges. This synergistically drives the proximal and distal interphalangeal joints to flex rapidly and significantly, forming a clenched posture. At this time, the driving units simulating the central tendon bundle and the lateral tendon bundle of the extensor muscles remain in a de-energized and relaxed state to avoid generating antagonistic forces. When a precise pinching action is required, the control system first activates the miniature actuator that simulates the cochlear muscle, causing it to contract slightly to pretension the flexor tendon path and regulate muscle tension balance. Subsequently, a precise, moderate-intensity excitation is applied to the actuator that simulates the flexor digitorum profundus, causing moderate flexion of the distal interphalangeal joint, while the actuator that simulates the flexor digitorum superficialis is kept in a low-excitation or relaxed state to maintain near-extension of the proximal interphalangeal joint. During this process, the actuators of the central tendon bundle unit and the lateral tendon bundle unit that simulate the extensor muscle are independently given low-intensity excitation to provide adjustable antagonistic stiffness to stabilize the joint posture. The lateral angle of the fingertip can be finely adjusted by differentially controlling the actuators on both sides of the lateral tendon bundle actuator unit, ultimately achieving a stable, precise, and shape-adaptive pinching operation.

[0107] In some embodiments, the bionic finger motion control device also integrates sensors integrated into the device, including at least one of the following: a strain sensor disposed on a flexible electro-actuator for detecting its deformation or output force; an angle sensor disposed at the joint of the knuckle structure for detecting the joint flexion / extension angle; and a tactile sensor array disposed in the fingertip or fingertip area of ​​the knuckle structure for detecting contact pressure and distribution.

[0108] In one embodiment, the strain sensor can be directly attached to or embedded in the body or electrodes of the flexible electro-actuator in the form of a flexible circuit or a nano-sensitive material coating. It detects the active deformation or micro-stress changes in the output in real time after energization, and this signal directly corresponds to the instantaneous output state of the actuator. The angle sensor, employing a miniature Hall effect encoder or flexible strain gauge, is installed near the joint rotation axis of the knuckle structure to accurately measure the real-time flexion / extension angle of the joint, providing kinematic feedback to the end effector. The tactile sensor array, composed of distributed miniature pressure sensing units, is integrated under the flexible skin of the fingertip or fingertip area of ​​the knuckle structure to detect the magnitude, distribution center, and torque information of pressure when in contact with an object at high resolution. The signals from these sensors are fed to an external collaborative controller in real time. The controller calibrates the drive input based on the strain signal, controls the motion trajectory in a closed loop based on the angle signal, and adjusts the grasping force and posture in real time based on the tactile signal, thereby jointly achieving adaptive, high-precision bionic motion control with proprioception and environmental interaction capabilities.

[0109] In some embodiments, the bionic finger motion control device further includes a controller electrically connected to a sensor and a flexible electro-actuator, for performing coordinated closed-loop control of the flexible electro-actuator according to the target motion command and the sensor feedback signal, to achieve position control, force control or impedance control.

[0110] In one embodiment, the controller acts as the central hub of the bionic finger motion control device, establishing real-time electrical connections with the drive circuits of all flexible electro-actuators and various sensors through its input / output interfaces. Specifically, the controller can simultaneously read multimodal feedback signals from angle sensors, strain sensors, and tactile sensor arrays based on received target motion commands (such as "pinch with a force of 2N"). Subsequently, the controller calculates and fuses the target commands and real-time feedback based on a preset hand dynamics model and control algorithm. In position control mode, it dynamically adjusts the excitation amount of each actuator according to the angle deviation to accurately track the joint angle trajectory. In force control mode, it independently adjusts the output force of relevant actuators based on tactile pressure feedback to achieve a stable grasping force. In the more complex impedance control mode, it coordinates antagonistic flexor and extensor muscle actuator groups to adjust the equivalent stiffness and damping of the joint in real time, enabling the finger to smoothly adapt to external disturbances. Ultimately, the controller generates a series of coordinated and independent pulse width modulation (PWM) signals and sends them to each actuator, forming a fully closed-loop control system from sensing and decision-making to execution, thereby achieving precise and adaptive control of the position, force, or mechanical impedance of the bionic finger movement.

[0111] This controller integrates multimodal sensor feedback and control algorithms to achieve collaborative closed-loop control of distributed flexible electro-actuators. Specifically, it can transform the hardware bionic potential of bionic fingers into practically usable intelligent motion capabilities. It not only achieves precise and adaptive control of position, force, and impedance, but also makes finger movements both highly accurate and naturally compliant, reducing the programming threshold for realizing complex grasping gestures and dynamic interactions. Thus, it completes a key leap from "mechanical drive" to "bionic intelligence" at the system level.

[0112] The following specific embodiments illustrate the bionic finger motion control device provided in this application.

[0113] Example 1

[0114] This embodiment provides a bionic finger motion control device with a basic flexible electro-actuated unit and a finger-adaptive substrate structure, the specific structure of which includes:

[0115] The flexible electro-actuation unit has a stacked structure, including: a driving layer (composed of electro-actuation materials such as dielectric elastomers or ionomer-metal composites), a first flexible electrode layer, and a second flexible electrode layer (attached to the upper and lower surfaces of the driving layer, respectively). The passive constraint structure is a fiber-reinforced layer attached to the outside of the upper electrode layer. This fiber-reinforced layer is formed by unidirectionally arranging high-strength carbon fibers or Kevlar fibers in a single direction (i.e., the preset driving direction) and embedding them in a silicone matrix and curing them. When a driving electric field is applied between the electrode layers, the driving layer material undergoes active deformation (such as in-plane expansion of the dielectric elastomer as it thins). Due to the extremely high stiffness of the fiber-reinforced layer in the direction perpendicular to the fiber (width direction), deformation is strongly suppressed; while the stiffness along the fiber direction (length direction) is relatively low, allowing the material to extend or contract relatively freely. If both ends of the unit are constrained, the net effect is manifested as a macroscopic driving displacement or contraction force along the length direction. The angle between the fiber direction and the driving direction is preferably less than 10 degrees.

[0116] The finger adapter substrate is a flexible, multi-layered structure that conforms to the inner side of the robot's finger skeleton or skin. The main body of the substrate is made of thermoplastic polyurethane (TPU) or silicone, with a thickness of approximately 0.5-2 mm, and its contour conforms to the curved surface of the phalanx. Multiple anchor bosses and corresponding insulating slots are precisely molded on the inner side of the substrate (closer to the phalanx) for mechanically locking and electrically insulatingly securing the fixed ends of the flexible electro-actuator units. A network of micro-tendon channels is pre-embedded or molded within the substrate, with a low-friction coating on the inner walls of the channels. At the anatomical locations corresponding to the A1-A4 pulleys in the human finger, micro-low-friction guide rings made of polyoxymethylene (POM) or ceramic material are embedded, simulating the function of pulleys to guide the linear or strip-shaped flexible electro-actuators passing through them, changing their force direction and reducing frictional loss.

[0117] Example 2

[0118] This embodiment provides a biomimetic finger motion control device with a linear driving fiber bundle unit and its biomimetic arrangement in the finger. The specific structure is as follows:

[0119] The linear flexible electroactuator is a slender cylindrical shape with a diameter of approximately 0.5-2 mm. Its core is a porous or solid inner core made of an electroacting material (such as silicone filled with dielectric particles). Elastic yarns impregnated with silver nanowires, carbon nanotubes, or conductive polymers are wound or woven around the inner core, forming a spiral or mesh-like electrode layer. The outermost layer is a constraint-guiding sheath layer tightly woven from ultra-high molecular weight polyethylene (UHMWPE) fibers or aramid fibers at a braiding angle of 15°-30°. This sheath layer constitutes a passive constraint structure, providing extremely high radial constraint stiffness, efficiently converting the expansion energy of the inner core under an electric field into strong contraction along the axis, forming a high-performance "artificial tendon."

[0120] The linear "artificial tendon" is arranged within a single bionic finger. The finger adapter base is fitted onto a phalanx model. Multiple bundles of these linear actuating fibers serve as flexible electroactors, configured according to human hand anatomy.

[0121] The flexor drive unit group includes two drive fiber bundles simulating the flexor digitorum profundus muscles. Their pathways originate from the metacarpal base anchor point, pass through all pulley guide rings, and terminate at the distal phalanx anchor point. It also includes two drive fiber bundles simulating the flexor digitorum superficialis muscles, running parallel to the flexor digitorum profundus bundles and terminating at the middle phalanx anchor point.

[0122] The extensor drive unit group includes a drive fiber bundle simulating the central tendon bundle, which runs along the dorsal side of the finger and terminates at the dorsal anchor point of the middle phalanx, primarily responsible for extending the metacarpophalangeal joint and proximal interphalangeal joint. It also includes two drive fiber bundles simulating the lateral tendon bundles, which run along the dorsal sides and converge after passing through the distal guide ring to terminate at the dorsal side of the distal phalanx, working together to achieve distal interphalangeal joint extension.

[0123] Cochlear muscle simulation unit: It uses four finer micro-drive fiber bundles that start from the anchor point near the metacarpal head, pass through a special channel in the interdigital web, and attach to the side of the extensor device (simulating the extensor tendon cap). Its contraction can coordinate flexion and extension balance and produce slight finger adduction or abduction movements.

[0124] The aforementioned drive unit assembly is anchored in the corresponding slot of the finger adapter base via its fixed end, and its free end is connected to the attachment point on the phalanx or directly to the phalanx structure via a micro-connector. The flexor and extensor muscle groups functionally form a spatially antagonistic pair.

[0125] Example 3

[0126] This embodiment provides a bionic finger motion control device with an integrated sensing and closed-loop control intelligent finger device structure, the specific structure of which is as follows:

[0127] Flexible fiber grating (FBG) strain sensors or printed resistive strain gauges are integrated between the constraint guide sheath and the inner core of each driving fiber bundle, or at its end connector, to measure the axial strain or contractile force of the driving fiber bundle in real time and accurately, forming a force sensing closed loop.

[0128] At the rotation axis of each finger joint (metaphalic joint, proximal interphalangeal joint, distal interphalangeal joint), a flexible resistive or capacitive angle sensor is printed on the finger adapter substrate to measure the flexion / extension angle of each joint in real time, forming a position sensing closed loop.

[0129] On the surface of the finger functional parts in the fingertip sleeve and finger pad area, there is an integrated array of capacitive or piezoresistive tactile sensors with a resolution of 1-2mm. These sensors are used to sense the pressure distribution, slippage, and texture information of the contacted object, thus forming an external interactive sensing mechanism.

[0130] An embedded microcontroller is integrated as a local controller into the proximal end of the hand or fingers. This controller is electrically connected to the electrode layers of all drive fiber bundles and all sensors. Its workflow is as follows: it receives "finger movement commands" (such as "pinch the fingertip with 3N force" or "bend the joint to [θ1, θ2, θ3]") from an upper-level system (such as a robot controller). The controller internally stores joint kinematics models, drive fiber bundle force-displacement characteristic models, and antagonistic cooperative control laws. It parses high-level commands into target contraction force sequences or target length sequences for each drive fiber bundle. While outputting high-voltage drive signals, it reads feedback signals from force and angle sensors in real time, dynamically adjusting the voltage of each drive unit through closed-loop algorithms such as PID or model predictive control (MPC) to ensure accurate tracking of output force or joint angle, achieving position control, force control, or impedance control modes.

[0131] Figure 6 This is a schematic diagram of the structure of a robot bionic hand motion control device provided in one embodiment of this application.

[0132] Reference Figure 6 As shown, the robot's bionic hand motion control device 60 may include multiple bionic finger motion control devices 10 (including bionic finger motion control devices 1 to n) provided in any embodiment of this application, each corresponding to multiple fingers of the robot; and a hand-level collaborative controller 601, used to coordinate each finger to perform a target motion, the target motion including at least one of grasping, pinching, and multi-finger collaborative operation.

[0133] In some embodiments, the hand-level collaborative controller is configured to: receive task instructions; plan the motion trajectory and force distribution of each finger based on a pre-stored hand kinematics and dynamics model; generate collaborative control instructions for the driving devices of each finger, and send the collaborative control instructions to the driving devices of each finger to drive the bionic robotic hand to perform operations corresponding to the task instructions; receive sensor feedback from each finger, and adjust the control instructions in real time based on the feedback to achieve overall coordination and stability control.

[0134] In one implementation, based on Figure 4 The demonstrated bionic hand motion control device for robots features a hand-level collaborative controller that receives high-level task commands such as "grasping a water cup." This controller breaks down the received commands into sub-tasks and motion parameters for each finger (thumb, index finger, etc.). Subsequently, based on a pre-set kinematic and dynamic model of the entire hand, the hand-level collaborative controller generates precise, coordinated timing commands and sends them to the independent controllers and drive circuits within each corresponding bionic finger motion control device. Multiple flexible electro-actuators within each finger device are thus independently and collaboratively excited, converting deformation into precise mechanical movements through their internal passive constraint and guiding structures. This ultimately drives each phalanx to perform actions such as thumb-to-palm opposition and flexion-envelope movements. During this process, sensors in each finger (such as joint angles and fingertip tactile feedback) provide real-time feedback. The hand-level controller dynamically fine-tunes the motion parameters and force distribution of each finger based on this global information to ensure the stability and adaptability of the entire grasping action. This bionic hand motion control device for robots achieves a leap from single-finger bionics to highly coordinated multi-finger movements, enabling the robot hand to perform complex grasping, fine pinching, and multi-finger dexterity operations as an organic whole. This greatly improves the flexibility, adaptability, and task execution efficiency of operations. At the same time, its distributed and modular architecture reduces the complexity of system integration and control.

[0135] The following specific embodiments illustrate the robot bionic hand motion control device provided in this application.

[0136] Example 4

[0137] This embodiment provides a multi-finger collaborative bionic hand device. The robotic bionic hand motion control device includes five bionic finger motion control devices (50T, 50I, 50M, 50R, 50L) corresponding to the thumb, index finger, middle finger, ring finger, and little finger, respectively. The drive unit, sensor, and local controller of each finger are connected to a hand-level collaborative controller located in the palm base via a flexible printed circuit (FPC).

[0138] The hand-level collaborative controller consists of a high-performance embedded processor, which has a complete database of hand kinematics and dynamics models, common grip types (such as force grip, precision grip, and side pinch), and multi-finger collaborative motion planning algorithms.

[0139] The collaborative control process is as follows:

[0140] 1. Command Reception and Parsing: Receives advanced task commands such as "grab a cylinder (40mm in diameter)" or "execute OK gesture".

[0141] 2. Motion and Force Planning: Based on task instructions and object models (or visual information), plan the expected fingertip trajectory, contact point position, and required gripping force distribution for each finger to ensure gripping stability and object protection.

[0142] 3. Command decomposition and issuance: The planning results are decomposed into specific sub-commands for each finger's local controller (such as target angles of each joint or target force vectors of each fingertip).

[0143] 4. Collaborative Execution and Stable Control: Each finger's local controller drives its flexible electro-actuator to perform actions. The hand-level collaborative controller receives real-time feedback from force, angle, and tactile sensors of all fingers, and runs a grip stability criterion algorithm (such as force closure check). When object slippage or uneven force is detected, the force commands allocated to each finger are immediately adjusted online to achieve adaptive and stable gripping.

[0144] Figure 7 This is a flowchart illustrating a bionic hand control method provided in one embodiment of this application.

[0145] Reference Figure 7 As shown, this method can be applied to the robot bionic hand motion control device provided in any embodiment of this application, and may specifically include the following steps:

[0146] S1: Receive motion commands;

[0147] S2: Based on a pre-stored finger motion model or multi-finger coordination model, the motion command is parsed into a coordinated drive signal for the multiple flexible electro-actuators;

[0148] S3: Output the drive signal to drive the knuckle structure to generate corresponding knuckle movements or hand coordination operations, and can perform closed-loop adjustments based on sensor feedback.

[0149] Regarding S1

[0150] In one implementation, the hand-level collaborative controller can receive task instructions from external sources (such as a user teach pendant, a higher-level decision-making system, or a pre-programmed program) via its communication interface (such as CAN, EtherCAT, or a wireless module). These task instructions are typically expressed in the form of abstract goals, such as "grasp a cylinder with a diameter of 50 mm," "pinch a thin sheet with a force of 0.5 N," or "make an 'OK' gesture." The instructions may contain semantic information such as the target location, trajectory, force, or gesture type.

[0151] This step defines a clear human-machine or system interaction interface, encapsulating complex biomimetic motion requirements into high-level, easy-to-understand, and programmable instructions, greatly simplifying the operator's control burden and providing clear target inputs for subsequent intelligent analysis and execution.

[0152] Regarding S2

[0153] In one implementation, the hand-level collaborative controller invokes its internally stored or online-calculated digital bionic model. For single-finger movements, based on the finger kinematics and dynamics model, the target joint angle or fingertip force is mapped to the required length change or output force of each actuator. For multi-finger collaborative operations, a multi-finger collaborative model (such as a grasping mechanics model) is invoked to calculate the force distribution and motion timing of each finger and even each joint. Through model calculation, the abstract instructions in S1 are parsed into a set of time-synchronized and spatially coupled low-level physical control parameters, i.e., generating specific drive signals for each flexible electro-actuator (e.g., duty cycle, frequency, and phase relationship of each channel's PWM wave).

[0154] This step transforms biomechanical principles (models) into executable engineering control signals, achieving automated and precise conversion from high-level intent to low-level drive. This avoids the difficulty of manually designing complex drive waveforms. Furthermore, model-driven analysis ensures the biomimetic rationality of the movements, such as naturally coordinating antagonistic muscle groups and optimizing energy distribution. It also provides the system with strong reconfigurability and adaptability, allowing for completely different motion modes to be achieved simply by changing the model or input parameters.

[0155] Regarding S3

[0156] The hand-level collaborative controller sends the collaborative instructions (i.e., the local motion and force targets of each finger) parsed by S2 to each finger controller. Each finger controller then outputs specific electrical signals through its multi-channel independent drive circuit, applying them to the flexible electro-actuators under its jurisdiction. The actuators generate active deformation under electric field excitation. This deformation is oriented and converted into mechanical displacement or force by the passive constraint structure, and then drives the finger joint structure to move through the force transmission path guided by the guide structure. Simultaneously, multi-modal sensors integrated into the device collect physical state information such as deformation, joint angle, and contact force in real time, and feed it back to the corresponding finger controller. Each finger controller compares the real-time data fed back by the sensors with the received local targets. If there is a deviation, it independently and quickly adjusts the drive signals output to each actuator under its jurisdiction online based on a closed-loop control algorithm to achieve precise trajectory tracking, constant force maintenance, or compliant impedance interaction for its own finger. At the same time, each finger controller reports a key execution state summary to the hand-level collaborative controller, which decides whether cross-finger task replanning or collaborative strategy adjustment is needed based on the overall task completion status and environmental changes.

[0157] This step achieves reliable execution from coordinated commands to precise physical actions through a hierarchical closed-loop control architecture. On one hand, by delegating the high real-time servo closed loop to each finger controller, high-precision, high-response speed, and robust control of individual finger movements are achieved. On the other hand, the collaboration between the hand-level controller and the finger controllers ensures that each finger can quickly adapt to environmental changes (such as object sliding or irregular shapes) based on local sensors, and also achieves dynamic coordination of multiple fingers at the global task level, thus endowing the hand as a whole with dynamic and smooth complex interaction capabilities. Furthermore, the clear division of responsibilities forms an efficient two-level "perception-decision-execution" closed loop, enabling the system to combine the advantages of modular independent control with overall intelligent collaborative capabilities, significantly improving the success rate of complex operations and the system's scalability.

[0158] The following specific embodiments illustrate the bionic hand control method provided in this application.

[0159] Example 5

[0160] S501: Receives motion commands. The command source can be a direct user command, an upper-level task planner, or a reflex action triggered by environmental perception (such as a camera) (such as obstacle avoidance and hand retraction).

[0161] S502: Model parsing and cooperative signal generation. The controller calls the corresponding pre-stored model according to the instruction type.

[0162] If the motion command is a single-finger action command, the finger motion model of that finger (including the mapping relationship between joint kinematics and driving units) is invoked, and the target signals of each driving fiber bundle are parsed out.

[0163] If the motion command is a multi-finger cooperative operation command (such as grasping), then the multi-finger cooperative model is invoked. First, multi-finger motion planning and force distribution are solved. Then, the results are decomposed into the targets for each finger, and then the cooperative driving signals for all driving fiber bundles are generated through the motion models of each finger. This process may include feedforward compensation for coupling effects between multiple driving units.

[0164] S503: Output drive and closed-loop adjustment. The generated coordinated drive signal (typically a voltage-time series) is output to the corresponding flexible electro-actuator. Simultaneously, feedback signals from force sensors, angle sensors, and tactile sensors are acquired in real time.

[0165] S504: Feedback Comparison and Adjustment. The actual values ​​(force, position, contact state) fed back by the sensors are compared with the expected values ​​generated in step S520 to generate an error signal. The drive signals output to each drive unit are dynamically adjusted using a preset closed-loop control algorithm (such as PID or impedance control algorithm) to eliminate errors and ensure the accuracy, compliance, and stability of motion or operation. For grasping tasks, this adjustment is performed continuously online to adapt to object deformation or external disturbances.

[0166] This application also provides a robot, which may include the bionic finger motion control device or the robot bionic hand motion control device provided in any embodiment of this application.

[0167] The robot provided in this application will be specifically illustrated through specific embodiments below.

[0168] Example 6

[0169] This embodiment specifically provides a bionic humanoid robot or dexterous work robot, which integrates a bionic hand motion control device as described in Embodiment 4 at its wrist or forearm end. This hand device is connected to the robot arm via a mechanical interface, and its hand-level collaborative controller communicates with the robot's central control system via a high-speed bus. This robot can perform a variety of tasks, from simple object grasping and handling to complex tool use (such as writing with a pen or cutting with a knife), gesture expression, and smooth and safe physical interactions with humans (such as shaking hands), greatly improving the robot's practicality and naturalness of interaction in service, medical, industrial, and home environments.

[0170] The technical solutions provided in this application can achieve at least the following technical effects:

[0171] 1. Solved the challenges of structural integration and biomimetic layout: By combining a "finger-adaptive substrate" with a biomimetic flexible electro-actuator, the traditional motor and rigid transmission chain are replaced, enabling multiple drive units to be integrated in a limited hand space with a highly biomimetic topology (such as flexor / extensor antagonistic pairs), achieving a compact and lightweight structure.

[0172] 2. Achieved smooth motion and quiet operation: Flexible electro-actuators are based on electric field actuation and have no mechanical moving parts, fundamentally eliminating noise and vibration. Their inherent continuous deformation characteristics, combined with the precise guidance of passive constraints, can produce smooth and continuous motion output, overcoming the stiffness of rigid systems.

[0173] 3. Enables precise force control and adaptive interaction: The antagonistic drive design based on simulated anatomy provides the physical basis for precise force distribution. Combined with multimodal sensors (force, angle, tactile) and a closed-loop controller, it enables precise force / position / impedance hybrid control, giving the hand the ability to adaptively grasp, compliantly contact, and perform fine manipulation.

[0174] 4. A collaborative intelligent control closed loop from single-finger to multi-finger: The device and method form a complete system of "intra-finger collaboration → inter-finger hand collaboration → closed-loop control based on sensor feedback". This system can parse task instructions into specific collaborative driving signals and adjust them in real time, realizing intelligent execution from simple actions to complex operation tasks, and improving the robot's functionality and autonomy.

[0175] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A bionic finger movement control device, characterized in that, A bionic finger for robotic applications, the bionic finger comprising a finger adapter base whose shape is configured to match the profile of a mounting surface of a robotic palm or finger; and at least one phalanx structure; the bionic finger motion control device comprising: Multiple flexible electro-actuators, including an electro-actuating material capable of active deformation under electric field excitation, wherein one end of each flexible electro-actuator is fixed and connected to the finger adapter substrate, and the other end is free and connected to the knuckle structure through a force transmission path; wherein each flexible electro-actuator can be independently controlled, and the multiple flexible electro-actuators work together to drive the knuckle structure to produce biomimetic motion; A passive constraint structure is configured to provide anisotropic mechanical constraints on the active deformation of the flexible electro-actuator, thereby guiding the active deformation and converting it into a driving displacement or driving force along a first preset direction. A guiding structure, disposed in the finger adapter base or the force transmission path, is used to guide the deformation direction of the flexible electro-actuator; The finger adapter base has an anchor point array and an insulating slot system corresponding to the finger bone on its inner side for fixing the fixed end of the flexible electro-actuator; a tendon channel and a guide ring simulating the human body pulley structure are formed inside the base, and the tendon channel and the guide ring constitute the guide structure. The plurality of flexible electro-actuators are configured to simulate the anatomical topology of the flexor and extensor muscles of the human hand, forming a flexor drive unit group and an extensor drive unit group. The free ends of the flexor drive unit group and the extensor drive unit group are respectively connected to different attachment positions of the phalanx structure through their respective force transmission paths to form a spatial antagonistic pair.

2. The apparatus according to claim 1, characterized in that, The flexible electro-actuator includes a driving layer, a first flexible electrode layer, and a second flexible electrode layer stacked together. The driving layer is composed of the electro-actuating material; The first flexible electrode layer and the second flexible electrode layer are respectively disposed on both sides of the driving layer to apply a driving electric field; The passive constraint structure is coupled to the flexible electric actuator or the driving layer.

3. The apparatus according to claim 2, characterized in that, The passive constraint structure is a structure with anisotropic stiffness, and the anisotropic stiffness structure includes at least one of the following: The mesh structure constraint layer is configured to have a low equivalent tensile stiffness in the preset direction; Sheet-like intrinsically anisotropic material layer; Discrete rigid constraint elements are distributed along the preset direction.

4. The apparatus according to claim 3, characterized in that, The mesh structure constraint layer is a fiber reinforcement layer, and the high-strength fibers in the fiber reinforcement layer are arranged along a second preset direction.

5. The apparatus according to claim 1, characterized in that, The flexible electro-actuator includes one or more inner cores made of the electro-actuating material, and a spiral or mesh-like flexible electrode layer surrounding the inner cores; and The passive constraint structure includes a constraint guide sheath layer made of high-strength fibers that covers the outside of the flexible electro-actuator; The flexible electric actuator is linear and has a circular or elliptical cross-section.

6. The apparatus according to claim 1, characterized in that, The finger adapter substrate comprises a multi-layered composite flexible substrate.

7. The apparatus according to claim 1, characterized in that, The flexor drive unit group includes: A drive unit simulating the flexor digitorum profundus and flexor digitorum superficialis muscles, the extensor drive unit group including drive units simulating the central tendon bundle and lateral tendon bundles; and Miniature drive units that mimic the cochlear muscle are used to coordinate flexion-extension balance and lateral control.

8. The apparatus according to claim 1, characterized in that, It also includes sensors integrated into the device, the sensors comprising at least one of the following: A strain sensor mounted on the flexible electro-actuator is used to detect its deformation or output force. An angle sensor is installed at the joint of the phalanx structure to detect the joint flexion / extension angle; An array of tactile sensors is disposed in the fingertip or fingertip area of ​​the knuckle structure to detect contact pressure and distribution.

9. The apparatus according to claim 8, characterized in that, It also includes a controller, which is electrically connected to the sensor and the flexible electro-actuator, and is used to perform coordinated closed-loop control of the flexible electro-actuator according to the target motion command and the sensor feedback signal to realize position control, force control or impedance control.

10. A bionic hand motion control device, characterized in that, Includes multiple bionic finger motion control devices as described in any one of claims 1-9, each corresponding to a multiple finger of the robot; and A hand-level collaborative controller is used to coordinate the execution of target movements by each finger, the target movements including at least one of grasping, pinching, and multi-finger collaborative operation.

11. The apparatus according to claim 10, characterized in that, The hand-level collaborative controller is configured as follows: Receive task instructions; Based on the pre-stored hand kinematics and dynamics model, the movement trajectory and force distribution of each finger are planned; Generate coordinated control commands for the driving devices of each finger, and send the coordinated control commands to the driving devices of each finger to drive the bionic robotic hand to perform operations corresponding to the task commands; The system receives sensor feedback from each finger and adjusts control commands in real time based on the feedback to achieve overall coordination and stability control.

12. A bionic hand control method, characterized in that, The device implementation according to any one of claims 1-9 includes the following steps: Receive motion commands; Based on a pre-stored finger motion model or multi-finger coordination model, the motion command is parsed into a coordinated drive signal for the multiple flexible electro-actuators; The drive signal is output to drive the knuckle structure to produce corresponding knuckle movements or hand coordination operations, and closed-loop adjustments can be made based on sensor feedback.

13. A robot, characterized in that, It integrates a bionic finger motion control device as described in any one of claims 1-9 or a bionic hand motion control device as described in any one of claims 10-11.

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