Bionic robot lip movement control device and method and bionic robot

Abstract

The application provides a kind of bionic robot lip movement control device, method and bionic robot, belongs to bionic robot technical field.The device includes carrier, lip function part, a plurality of flexible electric actuators, including the electric actuating material capable of active deformation under electric field excitation, and based on the anatomical position and muscle fiber direction of target perioral expression muscle, it is arranged in bionic space, one end is connected to the carrier as fixed end, the other end is connected to the lip function part as free end;Passive constraint structure is configured to provide anisotropic mechanical constraint to the active deformation of flexible electric actuator, guide and convert the active deformation into driving displacement or deformation along the first preset direction;Flexible electric actuator is configured to generate driving displacement or deformation guided by passive constraint structure at its free end, to cooperatively drive the lip function part to generate composite lip deformation matched with target expression.By the cooperative driving of multiple electric actuators, highly bionic natural expression.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bionic robots, in particular to a bionic robot lip movement control device, a control method and a bionic robot comprising the device. BACKGROUND

[0002] With the rapid development of bionic robot technology, giving robots the ability to express personification and emotionalization has become a key research direction in the field of human-computer interaction. The expression driving of the lips and the surrounding area is one of the core technical challenges to realize natural and lively interaction of robot facial expressions.

[0003] At present, the robot lip driving scheme mainly adopts a rigid mechanical driving scheme, and the specific implementation technology adopts a micro motor, a rudder or a linear driver, which converts rotary motion into displacement of a specific point through a transmission mechanism such as a gear, a connecting rod or a worm gear. This type of scheme is mature in technology, has large output force and is simple to control, but has inherent limitations:

[0004] Complex structure and large space occupation: the complex transmission mechanism is difficult to integrate multiple drivers in the narrow and irregular space of the robot face, especially in the high-density area around the lips, which limits the freedom of movement and miniaturization of the structure.

[0005] Significant noise and vibration: the operation of the motor and the meshing of the gear will produce obvious audible noise and mechanical vibration, which seriously affects the realism and immersion of the user experience in close-range interaction scenarios.

[0006] Rigid and unnatural movement: the output is discrete or stepwise displacement, lacking the flexibility and continuity of biological muscle movement, resulting in a robot expression that appears stiff and mechanical, making it difficult to simulate the dynamic flow and subtle changes of human expressions. Especially for the "orbicularis oris muscle" which realizes the complex ring-shaped contraction function of lip closure and pouting, its muscle fibers are uniquely distributed around the mouth, and the traditional point-to-point linear driving method is difficult to reproduce its uniform, coordinated and soft transition of the contraction mode and shape.

[0007] Therefore, the bionic robot lip control scheme in the prior art is still difficult to achieve highly personified, natural and smooth and expressive lip movement due to the rigidity, noise and deficiencies in bionic principles of the rigid mechanism. There is an urgent need in the art for a solution that collaboratively innovates from driving principles, structural bionics to control strategies, which can accurately guide the deformation of flexible drivers and simulate the natural mechanical properties of expression muscles, thereby truly realizing the "deceivingly realistic" lip expression of robots. SUMMARY

[0008] To solve the problems of the existing robot lip driving scheme in the background art, such as large noise, stiff movement, complex structure, and difficulty in reproducing natural expressions, the application provides a bionic robot lip movement control device, method and robot.

[0009] In a first aspect, the application provides a bionic robot lip movement control device, comprising: a carrier; a lip function part; a plurality of flexible electric actuators, including an electric actuating material capable of active deformation under electric field excitation, and being arranged in a bionic space based on the anatomical position and muscle fiber direction of a target perioral expression muscle, one end of which is connected to the carrier as a fixed end, and the other end is connected to the lip function part as a free end; and a passive constraint structure configured to provide anisotropic mechanical constraint to the active deformation of the flexible electric actuator, thereby guiding and converting the active deformation into driving displacement or deformation along a first preset direction; wherein the flexible electric actuator is configured to generate driving displacement or deformation guided by the passive constraint structure at its free end, to cooperatively drive the lip function part to generate a composite lip deformation matching the target expression.

[0010] In a possible implementation, the target perioral expression muscle is selected from at least one of the following: orbicularis oris muscle, levator anguli oris muscle, depressor anguli oris muscle, levator labii superioris muscle, mentalis muscle, zygomaticus major muscle, risorius muscle, depressor labii inferioris muscle, buccinator muscle; and the angle between the arrangement direction of the flexible electric actuator and the main direction of the muscle fiber of the target expression muscle it simulates is less than 45 degrees.

[0011] In a possible implementation, the flexible electric actuator includes a driving layer, a first flexible electrode layer and a second flexible electrode layer arranged in layers; the driving layer is composed of the electric actuating material, and the first and second flexible electrode layers are arranged on both sides of the driving layer to apply a driving electric field; and the passive constraint structure is coupled with the driving layer.

[0012] In a possible implementation, the passive constraint structure is a structure body with anisotropic rigidity, which includes at least one of the following: a net structure constraint layer configured to have an equivalent tensile rigidity in the first preset direction lower than an equivalent tensile rigidity in at least one other direction; a sheet-shaped intrinsic anisotropic material layer configured to have a Young's modulus in the first preset direction lower than a Young's modulus in at least one other direction; and discrete rigid constraint elements distributed in a chain or strip shape along the first preset direction, thereby forming a continuous constraint path in a direction perpendicular to the first preset direction.

[0013] In a possible implementation, the net structure constraint layer is a fiber reinforced layer, including reinforced fibers arranged along a second preset direction.

[0014] In a possible implementation, the passive constraint structure is integrated with the first flexible electrode layer and / or the second flexible electrode layer, forming a composite functional layer with both electrically conductive function and anisotropic constraint function.

[0015] In a possible implementation, the passive constraint structure comprises a constraint guide provided on the carrier, the constraint guide having an extension trajectory matching a physiological motion arc of a target facial muscle, and at least a part of the flexible electro-actuator is matched with the constraint guide to constrain a deformation path of the flexible electro-actuator.

[0016] In a possible implementation, the constraint guide is a rigid constraint groove provided with a limiting slide, wherein a free end of the flexible electro-actuator or a transmission component connected with the free end is slidably matched with the limiting slide, and the flexible electro-actuator sequentially undergoes a first stage path motion constrained by the limiting slide and a second stage deformation after reaching a limiting end under excitation of a driving electric field.

[0017] In a possible implementation, the flexible electro-actuator is configured to generate linear expansion motion along a preset trajectory in the first stage path motion under the constraint of the limiting slide, and when the free end or the transmission component moves to the limiting end in the second stage deformation, the flexible electro-actuator, an adjacent flexible electro-actuator, and the lip function part generate coupling effect, triggering local nonlinear composite deformation.

[0018] In a possible implementation, the free end of the flexible electro-actuator and the lip function part are detachably connected through magnetic attraction connection structure.

[0019] In a possible implementation, the device further comprises a deformation sensing unit integrated in the device, configured to detect a deformation state of the lip function part and / or a deformation amount of the flexible electro-actuator in real time.

[0020] In a possible implementation, the device further comprises a controller electrically connected with the flexible electro-actuator, configured to perform cooperative closed-loop control on the flexible electro-actuator according to a target lip motion instruction and deformation information of the flexible electro-actuator, to realize the composite lip deformation.

[0021] In a second aspect, the application provides a method for controlling lip movement of a bionic robot, which is applied to the bionic robot lip movement control device provided in the first aspect. The method comprises: receiving a target lip expression instruction; analyzing the target lip expression instruction into a cooperative driving signal for the plurality of flexible electric actuators according to a pre-stored expression and driving mapping relationship; and controlling each flexible electric actuator to generate a driving displacement or deformation under the guidance of the passive constraint structure based on the cooperative driving signal, so as to cooperatively drive the lip function part to generate a complex lip deformation matching the target expression.

[0022] In a third aspect, the application provides a bionic robot, which comprises a head and the bionic robot lip movement control device provided in the first aspect, and the device is installed on the head.

[0023] The bionic robot lip movement control device provided by the technical scheme of the application comprises a plurality of flexible electric actuators arranged in a bionic space according to the anatomical positions and muscle fiber directions of target perioral expression muscles, each flexible electric actuator generates an active deformation when an electric field is excited, a passive constraint structure provides an anisotropic mechanical constraint to the active deformation, guides and converts the active deformation into a driving displacement or deformation along a first preset direction, and free ends of the flexible electric actuators are connected to a lip function part, so that the guided driving displacement or deformation is transmitted to the lip function part, and through the cooperation of the plurality of free ends, the lip function part is driven to generate a complex lip deformation matching the target expression. The implementation process is based on the cooperation of bionic arrangement and anisotropic constraint, so that the lip movement control can accurately reproduce complex expression changes, and the naturalness and coordination of the deformation are improved. Further, the bionic arrangement is used to replace the traditional rigid transmission, and the technical problems of complex structure, large noise and vibration, and unnatural movement are solved. The high-density integration and silent operation of the driver are realized, the deformation is accurately guided through the anisotropic constraint, the lip function part can reproduce the soft and cooperative movement like the orbicularis oris muscle, and natural and smooth, highly personified expressions are output. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A bionic robot lip movement control device structure schematic diagram is provided for an embodiment of the application;

[0025] Figure 2 A flexible electric actuator simulation arrangement schematic diagram is provided for an embodiment of the application;

[0026] Figure 3 A pouting expression driving schematic diagram is provided for an embodiment of the application;

[0027] Figure 4 A flexible electric actuator layered structure schematic diagram is provided for an embodiment of the application;

[0028] Figure 5 A schematic diagram of a driving unit for a composite functional structure provided in one embodiment of this application;

[0029] Figure 6 This is a schematic diagram of the drive and guidance of a constraint guide provided in one embodiment of this application;

[0030] Figure 7 This is a schematic diagram of an arc-shaped constraint structure provided in one embodiment of this application;

[0031] Figure 8 This is a schematic flowchart of a bionic robot lip movement control method provided in one embodiment of this application. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in detail below with reference to the accompanying drawings as one possible implementation. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application.

[0034] Figure 1 This is a schematic diagram of a bionic robot lip movement control device provided in one embodiment of this application.

[0035] Reference Figure 1 As shown, in one embodiment, the bionic robot lip movement control device 10 may include a carrier G1, a lip functional part G2, a plurality of flexible electro-actuators 101, and a passive constraint structure 102.

[0036] In another embodiment, the bionic robot lip movement control device 10 can be used to control the lip assembly of the bionic robot, wherein the lip assembly may include the carrier G1 and the lip functional part G2. Based on this, the bionic robot lip movement control device 10 may include a plurality of flexible electro-actuators 101 and a passive constraint structure 102.

[0037] It should be noted that the specific structure of the bionic robot lip movement control device provided in this application embodiment, i.e., whether it includes the carrier G1 and the lip functional part G2, can be configured according to the specific structure corresponding to the application. When the application object does not have a bionic robot lip component, the bionic robot lip movement control device provided in the corresponding embodiment of this application may include the carrier G1 and the lip functional part G2; if the application object has a bionic robot lip component, the bionic robot lip movement control device provided in the corresponding embodiment of this application may not include the carrier G1 and the lip functional part G2.

[0038] In some embodiments, a plurality of flexible electro-actuators 101 are made of electro-actuating materials that can actively deform under electric field excitation, and are arranged in a biomimetic spatial arrangement based on the anatomical position and muscle fiber orientation of the target perioral facial muscles. One end of each actuator is connected to the carrier as a fixed end, and the other end is connected to the lip functional part as a free end.

[0039] In one embodiment, the flexible electroactuator 101 is made of an electroactuating material, enabling it to undergo controllable active deformation under electric field excitation, which constitutes the core power source for lip movement. To accurately replicate the mechanical behavior of biological perioral muscles, these actuators are not randomly arranged, but rather biomimetically positioned in three-dimensional space strictly according to the anatomical location of the target perioral facial muscles and the natural direction of the muscle fibers. For example, refer to... Figure 2 As shown, multiple flexible electro-actuators 101 can be arranged biomimetously according to the anatomical location of the perioral muscles and the natural direction of the muscle fibers. One end of each flexible electro-actuator 101 is connected to a support (not shown) as a fixed end, providing a stable mechanical fulcrum for the driving action; the other end is directly connected to the lip functional part G2 as a free end, thereby efficiently and directly converting the active deformation generated by the electro-actuator into a driving action on the lip functional part. For example, the support can be a robot facial skeleton or substrate, and the lip functional part can be a biomimetic lip skin made of flexible materials such as silicone. Based on the above structure, a mechanical coupling relationship between the biomimetic driving array and the lip shape is directly established at the physical level, providing fundamental structural support for generating synergistic composite lip deformation with clear anatomical basis. Based on this structure, the working mode of complex facial muscle groups is simulated from the perspective of motion principle, ensuring that the direction of application of driving force is consistent with the direction of physiological movement, thus laying the foundation for realizing natural, coordinated and expressive lip movements.

[0040] In some embodiments, the passive constraint structure 102 is configured to provide anisotropic mechanical constraints on the active deformation of the flexible electro-actuator 101, thereby guiding the active deformation and converting it into a driven displacement or deformation along a first preset direction.

[0041] In one embodiment, the passive constraint structure 102 imposes a spatially asymmetric mechanical restriction on the often isotropic swelling deformation of the flexible electro-actuator 101 under electric field, through its physical configuration. This anisotropic restriction, for example by setting rigid guide components or fiber reinforced layers with high modulus in certain directions, physically strongly suppresses the deformation freedom of the electro-actuator material in other non-desired directions, thus directing and channeling its material-level active deformation energy to a pre-set first direction (e.g. mimicking the contraction direction of muscle fibers) that is consistent with the mechanical function of the target facial muscle. This key structural design efficiently and reliably translates the otherwise scattered and disordered material deformation into a well-defined vectorial driving displacement or controllable deformation with clear vectorial significance to the functional part of the lips. Based on this structure, the "mechanical rectification" and precise guidance of the flexible driver output are realized, fundamentally overcoming the inherent difficulties of simple flexible material in terms of poor driving directionality and low control precision, and ensuring that the mechanical vectors of multiple driver outputs can be precisely synthesized according to the bionics design, providing an indispensable mechanical transformation and directional basis for generating coordinated, controllable and natural composite lip movements.

[0042] In some embodiments, the flexible electro-actuator is configured to generate a driving displacement or deformation at its free end guided by the passive constraint structure, to cooperatively drive the functional part of the lips to generate a composite lip deformation matching the target facial expression.

[0043] In one embodiment, the free end of each flexible electro-actuator is directly connected to the functional part of the lips, constituting the final output interface and mechanical transmission node of the driving action. This physical connection ensures that the driving displacement or deformation with a specific direction, guided and translated by the passive constraint structure, can be directly applied to the corresponding area of the functional part of the lips without loss. The free ends of multiple electro-actuators form a discrete driving point array with clear spatial distribution and controlled action direction on the functional part of the lips according to their bionic arrangement. When they generate guided displacements synchronously or asynchronously according to control signals, these discrete driving points do not act independently, but integrate and superimpose their local displacements into a continuous and global surface deformation through the material continuity and mechanical coupling of the functional part itself. This structural mechanism provides physical support in that it converts multiple directional and discrete inputs into a coordinated and complex output through the mechanical synthesis mediated by the functional part. Based on this structure, a system originally driven by multiple simple linear or low-dimensional movements can emerge highly complex and nonlinear lip morphological changes, thus accurately and naturally reproducing complex expressions such as the upward movement of the corners of the mouth and the bulging of the cheeks when smiling, the overall forward movement and local wrinkling of the lips when pursing the lips, and other expressive composite expressions that require the cooperation of multiple muscles, realizing the key leap from controlled driver actions to lively expression outputs.

[0044] Figure 3 A pout expression driving diagram is provided for an embodiment of the present application.

[0045] Referring to Figure 3 In an embodiment, when pout expression driving control is performed, a plurality of flexible electro-actuators 101 simulating the circular fiber distribution of orbicularis oris muscle can be controlled in coordination, and flexible electro-actuators 101 for adjusting the muscle groups such as depressor anguli oris muscle can be supplemented. These activated flexible electro-actuators generate active contraction deformation under the synchronous driving electric field excitation. The deformation is guided by the passive constraint structure: for the flexible electro-actuators simulating the orbicularis oris muscle, the constraint trajectory is designed as a spatial path that surrounds the oral fissure, converges to the center, and slightly converges forward, so as to accurately convert the contraction of the flexible electro-actuator into the displacement of the free end along this trajectory, to the center of the lip, and forward (first preset direction).

[0046] These spatially surrounding distribution, directionally converging and forward pointing multiple driving displacements are applied to the vermilion region of the lip function part through the simultaneous and uniform application of each free end. The lip function part as a continuous elastic body plays a role in its material mechanics characteristics when bearing this circle of distributed centripetal-forward load: the local forward displacement is coupled and constrained to each other due to the continuity of the material, resulting in continuous and coordinated strain of the entire lip region (not just discrete driving points). Its macroscopic performance is that the lip soft tissue does not simply inwardly contract in a point shape, but presents a whole smooth protrusion forward, forming the core morphology of the pout. At the same time, under the continuous driving, due to the flexibility of the driver and the nonlinearity of the function part material, more delicate wrinkles or fuller protrusions can naturally be derived in the local stress concentration area such as the lip bead, and the auxiliary flexible electro-actuator (such as the flexible electro-actuator simulating the depressor anguli oris muscle) can provide slight mouth corner sinking or fixation to accurately control the morphology and emotional tone of the pout. The whole process realizes efficient and natural conversion from multiple directional linear driving inputs to complex three-dimensional morphology nonlinear outputs of the lip.

[0047] In some embodiments, the target perioral expression muscle is selected from at least one of the following: orbicularis oris muscle, levator anguli oris muscle, depressor anguli oris muscle, levator labii superioris muscle, mentalis muscle, zygomaticus major muscle, risorius muscle, depressor labii inferioris muscle, buccinator muscle; and an included angle between the arrangement direction of the flexible electro-actuator and the main direction of the muscle fibers of the target expression muscle simulated by the flexible electro-actuator is less than 45 degrees.

[0048] The structure design firstly covers the key muscle groups (such as orbicularis oris responsible for lip closure, zygomaticus major muscle and levator labii superioris muscle controlling the upper lip, depressor labii inferioris muscle and the like) that constitute the main perioral expressions of humans, thereby ensuring the anatomical basis of reproducing rich expressions in the functional coverage layer. On this basis, the spatial arrangement direction of the flexible electro-actuator is strictly limited to be highly consistent with the main direction of the muscle fibers of the specific target expression muscle it simulates (the included angle is less than 45 degrees). This specific physical structure design means that the vector direction of the driving force generated by each electro-actuator is basically coincident with the direction of the contraction force of the physiological muscle it simulates in the physical space. Based on the anatomical data and the accurate direction, the arrangement based on the arrangement ensures that the driving mode of the electro-actuator on the lip tissue is consistent with the biomechanical principle from the root of the mechanical transmission, so that the deformation of the lip function part not only simulates the cooperation of the real muscle group in appearance, but also simulates the cooperation in the internal mechanical path and cooperation mode, thereby providing a fundamental physical guarantee for generating highly realistic, anatomically logical and natural composite expressions.

[0049] Figure 4 A schematic diagram of the layered structure of the flexible electro-actuator is provided for an embodiment of the present application.

[0050] Referring to Figure 4 As shown in the figure, in some embodiments, the flexible electro-actuator includes a driving layer 40a, a first flexible electrode layer 40b and a second flexible electrode layer 40c arranged in layers. The first flexible electrode layer and the second flexible electrode layer are respectively arranged on both sides of the driving layer to apply a driving electric field.

[0051] In one embodiment, the driving layer is composed of an electro-actuated material, which can be a flexible electro-actuated material.

[0052] In one embodiment, the passive constraint structure is coupled to the flexible electro-actuator or the driving layer, and the passive constraint structure is coupled to the flexible electro-actuator or the driving layer in the same or similar way, and the specific coupling way is as follows:

[0053] I. Embedded or composite coupling:

[0054] In the current coupling structure, the corresponding materials of the passive constraint structure and the driving layer (or the flexible electro-actuator) are formed into a functional whole through interlacing or compounding during manufacturing. For example, it can be a fiber reinforced / woven constraint layer, which can be embedded or woven with high-strength and low-ductility fibers (such as carbon fibers, Kevlar fibers, metal wires) in a specific direction (non-isotropic) on the surface or inside of a sheet-shaped or columnar dielectric elastomer (driving layer). The fiber network constitutes the passive constraint structure.

[0055] In the current coupling structure, when the flexible electro-actuator is excited by electric field, the driving layer tries to expand. The extensible side deforms freely, while the non-extensible side (the constraint layer) greatly limits the strain in this direction, resulting in the whole structure only curling or bending towards the free side. The constraint layer and the driving layer are tightly "coupled" through adhesive or physical clamping, together determining the deformation mode. By using different stiffness of the constraint layer on one side or both sides of the electro-actuator, efficient bending drive can be easily achieved.

[0056] II. Laminated or assembled coupling:

[0057] In the current coupling structure, the layered passive constraint structure and the driving layer are independent thin layers that are physically attached together and work together. For example, the laminated structure can be an asymmetric laminated structure, in which one side or both sides of the driving layer (such as a dielectric elastomer film) is attached to a flexible sheet with asymmetric mechanical properties as a constraint layer. For example, one side is attached to a thin sheet with low elongation but softness (such as polyimide), and the other side is free or attached to an elastomer.

[0058] In the current coupling structure, when the flexible electro-actuator is excited by electric field, the driving layer tries to expand. The extensible side deforms freely, while the non-extensible side (the constraint layer) greatly limits the strain in this direction, resulting in the whole structure only curling or bending towards the free side. The constraint layer and the driving layer are tightly "coupled" through adhesive or physical clamping, together determining the deformation mode. By using different stiffness of the constraint layer on one side or both sides of the electro-actuator, efficient bending drive can be easily achieved.

[0059] III. Shell or skeleton coupling:

[0060] In the current coupling structure, the passive constraint structure is a pre-fabricated shell or skeleton with a specific geometric shape, which encapsulates or embeds the driving layer. For example, it can be a flexible shell with a pre-set deformation cavity, specifically a flexible shell made of silicone or polymer that wraps the driving layer. The shell has a non-uniform wall thickness, or has specific orientation of reinforcing ribs and cavities designed inside.

[0061] In the current coupling structure, the driving layer expands and its deformation is mechanically constrained by the shape of the shell. The direction with thin walls or cavities is more prone to expansion deformation, thus being "guided" to the pre-set deformation direction. The shell itself is the passive constraint structure, which is "coupled" with the driving layer through interference fit or adhesion. The shell not only provides constraint, but also protects the fragile electrodes and electro-actuating materials from physical damage and environmental effects.

[0062] IV. Integrated topology coupling:

[0063] In the current coupling structure, the boundary between the passive constraint structure and the driving layer is fused in the material or structural topology level. For example, a component can be manufactured by 3D printing or multi-material forming technology, which has a gradient change or anisotropic distribution of material stiffness or microstructure in space. The softer area acts as a "driving area", and the harder or microstructure with specific orientation area acts as a "constraint area".

[0064] In the current coupling structure, the flexible electro-actuator responds as a whole under the excitation of the electric field. The active deformation of the "driving area" is directly limited by the mechanical properties of the adjacent "constraint area" material, thereby producing directional macroscopic deformation. The constraint and driving are integrated and coupled in material and structure, and cannot be physically separated. Regions with continuously changing stiffness can be designed to achieve smooth and natural deformation closer to biological tissues.

[0065] In some embodiments, the passive constraint structure is a structure with anisotropic stiffness for realizing anisotropic mechanical constraint. The structure with anisotropic stiffness includes at least one of the following: a net-like structure constraint layer configured to have a lower equivalent tensile stiffness in the first preset direction; a sheet-like intrinsic anisotropic material layer; and discrete rigid constraint elements distributed along the preset direction.

[0066] In one embodiment, the anisotropic mechanical constraint can be realized by material layer compounding, such as embedding high-modulus fibers or films in a flexible matrix in a specific direction to form a laminated structure that is difficult to stretch in a specific direction and easy to deform in a vertical direction.

[0067] In another embodiment, the anisotropic mechanical constraint can be realized by microstructure design, such as processing periodic corrugations, grooves or honeycomb holes on the material to exhibit completely different deformation resistance in different directions. In other embodiments, other shapes can also be used, and the present application does not limit the shape.

[0068] In another embodiment, the anisotropic mechanical constraint can be realized by macroscopic mechanical structure, such as hinges, flexible joints or asymmetric grid frames, to directly construct mechanical devices that allow movement in a specific direction and restrict movement in other directions.

[0069] The anisotropic mechanical constraint provided by the structure with anisotropic stiffness in the above various embodiments can directly determine whether the final output is a linear force, a torque or a bending force, thereby replacing complex multi-motor coordination or precise motion control algorithms in a simple and reliable purely mechanical way.

[0070] In some embodiments, the structure with anisotropic stiffness is a constrained layer with a net-like structure; the constrained layer with a net-like structure is configured to have an equivalent tensile stiffness in a first preset direction lower than its equivalent tensile stiffness in at least one other direction, thereby realizing anisotropic mechanical constraint.

[0071] The constrained layer with a net-like structure realizes anisotropic stiffness through its specific geometric design: for example, the grid cells (such as holes) are arranged in an elongated oval or strip shape along a first preset direction, or the rod connections are designed to be sparser in this direction. This makes the grid easy to stretch by rod bending or hole deformation when the constrained layer is stressed in this first preset direction, exhibiting a lower equivalent tensile stiffness; while in other directions perpendicular or at a certain angle to it, the grid is difficult to be stretched due to the continuous structure or dense rod connections, thereby exhibiting a higher equivalent tensile stiffness. This anisotropic constraint with a stiffness ratio that can be precisely designed through a single material structure not only eliminates the interface failure risk of traditional multi-layer composite materials, but also enables the mechanical guiding characteristics of the drive unit to be flexibly "programmed" by adjusting the grid pattern, thereby achieving lightweight, high air permeability and better in-plane flexibility while ensuring excellent constraint effect.

[0072] In some embodiments, the structure with anisotropic stiffness is composed of a piece of intrinsically anisotropic material, and the Young's modulus of the intrinsically anisotropic material in a first preset direction is lower than its Young's modulus in at least one other direction.

[0073] When the passive constraint structure is composed of a single, uniform "intrinsically anisotropic material" piece, its anisotropic stiffness originates from the inherent molecular orientation or crystal structure directional arrangement within the material; for example, a polymer film made by unidirectional stretching process or a specific orientation of liquid crystal elastomer film. The mechanism of realizing anisotropic constraint is that the material has a lower Young's modulus in a first preset direction, which is easy to be stretched or compressed in this direction; while in at least one other direction perpendicular or at a certain angle to it, it has a significantly higher Young's modulus, thereby rigidly inhibiting deformation. This inherent difference in modulus makes the constraint layer "allow" a certain coordinated deformation of the drive layer along the low-modulus direction when the drive layer tries to expand, while "forcefully" preventing its deformation in the high-modulus direction, thereby guiding the output of the drive layer to the first preset direction. The above-mentioned method eliminates the interface failure risk between multi-layer materials and ensures the high uniformity and long-term stability of the constraint performance, as the anisotropy is provided by the intrinsic properties of the material, without the need for compounding, laminating or complex microstructure processing. This design makes the drive unit structure extremely compact, solid and consistent, which is particularly suitable for application scenarios with extremely high requirements for reliability, lightweight and miniaturization.

[0074] In some embodiments, the structure with anisotropic stiffness includes a plurality of discrete rigid constraint elements arranged in a chain or strip along a first preset direction, thereby forming a continuous constraint path in a direction perpendicular to the first preset direction.

[0075] The structure achieves anisotropic constraint by flexibly connecting (e.g., through hinges or flexible matrix) a plurality of discrete rigid constraint elements (e.g., micro rigid pieces or short rods) in a chain or strip along a first preset direction. When the driving layer deforms, the structure can bend or stretch like a chain in the first preset direction, exhibiting a low equivalent stiffness; while in a direction perpendicular to the first preset direction, these discrete elements, by virtue of their own rigidity and continuous arrangement, collectively form a nearly inextensible and solid "constraint wall", strongly inhibiting deformation. This ingenious design combines local flexibility with overall rigidity, ensuring that the driving unit can freely output movement or adapt to complex curved surface installation in a specific direction, while ensuring high reliability and stability in key constraint directions, thereby achieving efficient mechanical guidance while improving the geometric adaptability and structural durability of the driving unit in complex application scenarios.

[0076] In some embodiments, the net-like structure constraint layer can be a fiber reinforced layer, wherein the high-strength fibers in the fiber reinforced layer are arranged along a second preset direction, and the angle between the arrangement direction of the fibers and the first preset direction is less than a preset angle. For example, the preset angle can include 45 degrees. In other embodiments, the preset angle can also be other angle values, which are not limited in the present application.

[0077] The constraint guidance is achieved by arranging the fiber reinforced layer on the flexible electrode layer: high-strength fibers (such as carbon fibers, aramid fibers, or glass fibers) are embedded or attached to the surface of the flexible electrode layer (first and second flexible electrode layers) at an angle less than 45 degrees along a second preset direction. When the angle between the arrangement direction of the high-strength fibers and the "first preset direction" that needs to generate driving force is small, the fiber bundle can improve the tensile stiffness of the composite structure in a direction perpendicular to the arrangement direction of the fibers, thereby effectively inhibiting the expansion deformation of the driving layer in this direction; at the same time, along the arrangement direction of the fibers, the fibers can slide or bend relatively, still maintaining a low stiffness, allowing movement to be released along the "first preset direction". This design enables the flexible electrode layer to maintain electrical conductivity while having directional constraint mechanical properties, not only achieving high integration and lightweight of the structure, but also achieving precise and customizable design of the constraint stiffness and direction through a simple and reliable fiber arrangement process, thereby ensuring more efficient and controllable driving output.

[0078] In some embodiments, the passive constraint structure is integrated with the first flexible electrode layer and / or the second flexible electrode layer to form a composite functional layer that simultaneously has electrical conductivity and anisotropic constraint function.

[0079] In one embodiment, the passive constraint structure can include a first constraint layer and a second constraint layer.

[0080] In one embodiment, the single-sided integration can include fusing the first constraint layer and the first flexible electrode layer into a single functional layer by material compounding, for example, embedding conductive fillers into high modulus directionally-fiber reinforced elastomers. Or fusing the first constraint layer and the first flexible electrode layer into a single functional layer by structural integration design, for example, building microstructures with directional stiffness on conductive films. In this integration manner, the integrated side (i.e. the side of the functional layer resulting from the integration of the first constraint layer and the first flexible electrode layer) can both apply an electric field to the driving layer and provide directional constraints. The other side (the second constraint layer and the second flexible electrode layer, which are independently arranged) remains an independent functional layer, which is particularly suitable for application scenarios that require controllable bending or twisting, simplifying the structure on one side while retaining the flexibility of design.

[0081] In one embodiment, the single-sided integration can also include fusing the second constraint layer and the second flexible electrode layer into a single functional layer by material compounding, or fusing the second constraint layer and the second flexible electrode layer into a single functional layer by structural integration design. In this integration manner, the integrated side (i.e. the side of the functional layer resulting from the integration of the second constraint layer and the second flexible electrode layer) can both apply an electric field and provide directional constraints. The other side (the first constraint layer and the first flexible electrode layer, which are independently arranged) remains an independent functional layer. When there is a certain difference in the stiffness of the first constraint layer and the second constraint layer, the asymmetric mechanical properties of the driving unit can be constructed by the single-sided integration manner. The rigidly integrated side can provide strong and immediate deformation inhibition and guidance, while the opposite side (the side with weaker stiffness) realizes bending motion, thereby presetting the bending or twisting trend at the mechanical level.

[0082] Figure 5 A schematic diagram of a driving unit with a composite functional structure is provided for an embodiment of the present application.

[0083] Reference is made to Figure 5As shown, in one embodiment, the double-sided integration can include fusing the first constraint layer with the first flexible electrode layer into a functional layer 50a, and fusing the second constraint layer with the second flexible electrode layer into a functional layer 50b, thereby forming two independent composite functional layers with both "conduction" and "constraint" functions, with the intermediate layer being a driving layer 40a composed of electroactive material. This achieves a complete simplification and performance leap of the driving unit in structure and function. It completely eliminates the independent flexible electrode layer, and realizes zero-interface, synchronized operation of the electric field application and mechanical constraint on both sides, not only making the structure most compact and the reliability highest, but also ensuring that the deformation of the driving assembly in both directions can be most efficiently guided and converted, thereby achieving greater improvement in output density, response speed and energy efficiency.

[0084] In some embodiments, the passive constraint structure includes a constraint guide provided on the carrier, the constraint guide having an extension trajectory matching a physiological motion arc of the target facial muscle, and at least a portion of the flexible electro-actuator is matched with the constraint guide to constrain the deformation path of the flexible electro-actuator.

[0085] In one embodiment, the constraint guide is a physical structure fixed on the carrier, which defines an extension trajectory with a specific curvature. The trajectory is not arbitrarily set, but highly consistent with the natural motion arc of the target facial muscle (such as the arc-shaped lifting path of the lip elevator muscle or the surrounding contraction path of the orbicularis oris muscle) in the physiological state. In physical structure design, the flexible electro-actuator is matched with the trajectory through its body or transmission component in sliding or fitting, so that when the electro-actuator actively deforms under the excitation of the electric field, its motion is forced to be guided and can only develop along the pre-set, non-linear biomimetic trajectory. This mechanism directly converts the linear or in-plane expansion of the driver material into a path motion with a specific curvature and direction in accordance with the biomechanics. This structure solves the problem of the flexible driver's difficulty in spontaneously reproducing complex curve motion from the physical level, ensuring that the final motion form of the lip function part is consistent with the contraction trajectory of the real facial muscle not only at the displacement endpoint, but also in the dynamic path during the entire motion process, thereby greatly improving the fluency, naturalness and authenticity of the robot expression motion, and achieving accurate restoration of the details of biological motion.

[0086] In some embodiments, the constraint guide is a rigid constraint groove provided with a limiting slide; wherein the free end of the flexible electro-actuator or the transmission component connected thereto is slidably matched with the limiting slide, and the flexible electro-actuator sequentially experiences a first stage path motion constrained by the limiting slide and a second stage deformation after reaching the limiting end under the excitation of the driving electric field.

[0087] The flexible electric actuator generates linear extension motion along the preset trajectory in the first stage path motion, which is constrained by the limiting slide of the constraint guide. The flexible electric actuator, the adjacent flexible electric actuator and the lip function part generate coupling effect to trigger local nonlinear composite deformation in the second stage deformation when the free end or the transmission part moves to the limiting end.

[0088] Figure 6 The driving guide schematic diagram of the constraint guide is provided for an embodiment of the present application.

[0089] Referring to Figure 6 In an embodiment, the constraint guide is a rigid constraint groove provided on the carrier, and a limiting slide formed in the constraint guide constitutes a physical channel with clear geometric boundaries and end stop. The free end of the flexible electric actuator 101 or the transmission part 602 connected thereto forms slidable cooperation with the limiting slide 601 (such as through a sliding block, a roller or direct contact), which structurally realizes the key limitation of the movement degree of freedom of the free end of the flexible electric actuator, that is, forcibly restricts the multi-directional deformation of the flexible electric actuator under the driving electric field to movement along the only spatial path defined by the slide. This rigid and preset trajectory mechanical constraint is the fundamental physical basis for guiding the coordinated and directional motion of the discrete driver and finally synthesizing the composite deformation.

[0090] Specifically, in the first stage path motion, the active deformation force generated by the electric actuator pushes the free end (or the transmission part 602) to move along the limiting slide 601 after the driving electric field excitation is applied. In this stage, the rigid side wall of the limiting slide 601 continuously provides normal constraint to strongly suppress any deformation component deviating from the predetermined trajectory, thereby accurately converting the output of the electric actuator into nearly pure linear extension displacement in the direction of the limiting slide 601. This process is similar to a "linear actuator", which is accurate and controllable in motion and is the key to realizing basic expression profiles such as horizontally pulling apart the corners of the mouth.

[0091] When the free end moves and finally abuts against the limiting end of the limiting slide 601, the system enters the second stage deformation. At this time, the linear displacement of the free end is physically blocked, but the driving electric field can continue to be excited. The deformation potential energy stored in the electric actuator cannot be linearly released through the free end, so that the compliant body material of the electric actuator generates nonlinear bending, twisting or local bulging. At the same time, the deformation of the electric actuator interacts with the adjacent flexible electric actuator, which can be in different motion stages, through the lip function part to generate mechanical coupling. This coupling effect triggers complex stress distribution and strain field on the continuous elastic body of the lip function part, thereby emerging local nonlinear composite deformation such as wrinkles, protrusions or smooth transitions, which accurately correspond to delicate expression details such as protrusion of the lip pearl when pursing the lips and eversion of the lower lip when crying.

[0092] The two-stage mechanism described above, through a simple rigid structure, intelligently realizes the automatic switching of the driving mode: the first stage ensures the accuracy and repeatability of the basic movement; the second stage, on the basis of accurate displacement, uses the characteristics of flexible materials and system coupling to naturally derive rich morphological details. This enables a single driver to output a continuous spectrum of movements from simple units to complex forms, greatly enhancing the bionic expressiveness of individual driving units and the richness of the entire system's expression, while maintaining the simplicity and reliability of the structure.

[0093] In some embodiments, the free end of the flexible electro-actuator and the lip function part are detachably connected through a magnetic attraction connection structure.

[0094] The magnetic attraction connection structure is specifically composed of a pair of complementary magnets (such as permanent magnets and magnetic conductors, or permanent magnets with opposite polarities) arranged on the interface surfaces of the free end of the flexible electro-actuator and the lip function part, respectively, and the physical connection is achieved through the attraction force generated between the magnets. This design provides stable and reliable connection force in the physical structure to transmit driving displacement, while its "detachable" feature provides great convenience for quick replacement, maintenance or personalized adjustment (such as replacing different lip shapes) of the lip function part or individual electro-actuators. In addition, the magnetic attraction connection provides firm adhesion in the normal direction, while allowing small sliding or rotating freedom in the tangential direction, which provides the necessary mechanical compliance for the complex in-plane strain of the lip function part under the coordinated driving of multiple drivers, avoiding stress concentration or interference caused by completely rigid connection. The corresponding beneficial effects are to ensure driving transmission efficiency and synchronization, and significantly improve the modularity, maintenance convenience and movement reliability of the entire system.

[0095] In some embodiments, the device further comprises a deformation sensing unit integrated in the device, for real-time detection of the deformation state of the lip function part and / or the deformation amount of the flexible electro-actuator.

[0096] In an embodiment, the deformation sensing unit can be a micro-strain sensor, an optical encoder or a flexible curvature sensor, which can be directly integrated into the key areas of the lip function part and / or the body of the flexible electro-actuator, forming an in-situ sensing network integrated with the driving structure. The physical structure design enables direct and real-time capture of the local curvature, strain distribution and other subtle deformation states of the lip function part under the coordinated action of multiple drivers, and / or direct measurement of the deformation variables such as stretching and bending of each electro-actuator body. The high spatiotemporal resolution of the acquired sensing data provides the upper controller with accurate and multi-dimensional physical feedback on the current motion output. This setting constitutes an indispensable "sensory" basis for high-precision closed-loop adaptive control, enabling the system to compare the differences between "target expression" and "actual deformation" in real time and dynamically adjust the driving signals to compensate for material nonlinearity, individual differences and external disturbances, thereby greatly improving the accuracy and consistency of expression reproduction.

[0097] In some embodiments, the device further comprises a controller electrically connected to the flexible electro-actuators, for performing coordinated closed-loop control on the flexible electro-actuators according to the target lip motion instruction and the deformation information of the flexible electro-actuators, to realize composite lip deformation.

[0098] The controller is electrically connected to all flexible electro-actuators and deformation information sources (such as the deformation sensing unit integrated in the device or an external vision system). The specific process of coordinated closed-loop control can be as follows: the controller first receives the target lip motion instruction and parses it into a set of initial coordinated driving signals according to the pre-stored expression-driving mapping relationship and outputs them to each electro-actuator; then, the controller obtains real-time deformation information reflecting the actual motion state of the system (which can be directly obtained from the integrated deformation sensing unit or provided by an external sensing system), compares the measured information with the target deformation model, and calculates and dynamically adjusts the driving signal parameters (such as voltage amplitude, frequency or timing) applied to each electro-actuator in real time through the built-in control algorithm (such as PID, adaptive or model-based control algorithm), to accurately compensate for material nonlinearity, mechanical coupling interference and individual differences, thereby guiding all electro-actuators to cooperatively and adaptively output driving displacement and deformation that meet the target requirements under the cooperation of the passive constraint structure. The core benefit brought by this control architecture is that it realizes the leap from "open-loop instruction playback" to "closed-loop accurate reproduction", ensuring high fidelity, high repeatability and strong anti-interference capability of complex deformation of the lip function part, so that the robot can stably and reliably produce lively and natural expressions with high human likeness.

[0099] The bionic robot lip motion control device provided by the present application is described in detail through several specific embodiments.

[0100] Embodiment One

[0101] The embodiment provides a bionic robot lip motion control device, which can include a carrier (for example, a robot face skeleton or a base plate), a lip function part (for example, a bionic lip skin made of a flexible material such as silica gel), at least one flexible electric actuator, and a passive constraint structure.

[0102] The flexible electric actuator is made of a dielectric elastomer (DE), one end of which is anchored on the carrier as a fixed end through bonding or mechanical means, and the other end is a free end connected to the inner surface of the lip function part through a flexible connecting piece.

[0103] The passive constraint structure is attached to the fiber-reinforced layer of the electric actuator driving layer to precisely guide the deformation of the electric actuator. The fiber-reinforced layer has embedded reinforcing fibers (such as Kevlar fibers) arranged in a specific direction. The flexible electric actuator includes a stacked driving layer, a first flexible electrode layer, and a second flexible electrode layer.

[0104] The working process can be divided into two stages: in the first stage (linear guidance stage), after applying a driving electric field to the electrode layer, the driving layer undergoes thickness compression and in-plane expansion under the action of Maxwell stress. However, the reinforcing fibers of the fiber-reinforced layer provide high-strength constraints in the direction perpendicular to their arrangement, inhibiting the expansion of the driving layer in that direction (vertical direction). This anisotropic constraint precisely guides and converts the material's inherent isotropic expansion trend into almost completely linear expansion motion along the fiber arrangement direction (horizontal direction). This linear expansion is reliably transmitted to the lip function part through the connecting piece, achieving basic expressions such as horizontal stretching of the mouth corners (smiling) or tightening of the lip line, with precise and controllable motion. In the second stage (free deformation or composite guidance stage), when more complex lip shapes are needed (such as lip pearl protrusion caused by pursing the lips or eversion of the lower lip in a sad expression), a control strategy can be used to make the local area produce controlled, nonlinear eversion, bulging, or wrinkle deformation under the sustained electric driving force after the electric actuator reaches the predetermined linear displacement, utilizing its own compliance, coupling with adjacent actuators, and the material nonlinear characteristics of the lip function part. This two-stage mechanism of "precise guidance first, then soft derivation" enables a single electric actuator to reproduce complex lip movements rich in dynamic details, upgrading from simple displacement to natural morphological evolution.

[0105] Embodiment Two

[0106] The embodiment provides a humanized path and escape control integrated with a constraint guide rail.

[0107] The embodiment demonstrates a passive constraint structure integrated with mechanical guidance to achieve more humanized motion trajectories. Figure 7An arc-shaped constraint structure is provided for an embodiment of the present application. Referring to Figure 7 As shown in the figure, in the device, the passive constraint structure includes an arc-shaped constraint guide rail 702 fixed on the carrier G1, which limits the curvature of the sliding channel 601 and is carefully designed to be highly matched with the common physiological motion arc line of the human lips in expression expression (such as the upward arc line of the corners of the mouth when smiling). The free end of the flexible electric actuator 101 is connected with a transmission component 602, and the slider and the limiting sliding channel 601 form a slidable cooperation.

[0108] The control process clearly reflects the cooperation of "constraint motion" and "escape deformation": in the path constraint phase (such as the closed lip phase), the controller applies a driving electric field to make the flexible electric actuator 101 contract, and pull the transmission component 602 to strictly slide along the arc-shaped limiting sliding channel 601 to the lip midline. This process is completely constrained by the guide rail geometry, ensuring that the oral lip function part can smoothly close along a smooth arc line consistent with the anatomy, the action is natural and smooth, avoiding stiff linear motion. In the escape guide phase (such as simulating the pouting phase), after the double lips are closed, in order to form the pouting expression, the controller continues to increase the driving electric field. The flexible electric actuator 101 generates greater contraction force to drive the transmission component 602 to move to the guide opening at the end of the limiting sliding channel 601 and escape the lateral constraint of the guide rail. At the moment of escape, the transmission component 602 and the free end of the flexible electric actuator increase the degree of freedom of movement. Under the action of the continuous contraction force, the escaped transmission component 602 pushes the corresponding area of the oral lip function part (such as the lower lip middle part), so that the mechanical balance changes, thereby generating a soft, forwardly rolling protrusion deformation, vividly simulating the pouting expression. When resetting, the reverse voltage drives the electric actuator to stretch, and the transmission component 602 returns along the original route and re-embeds into the sliding channel. This "first path constraint, then freedom release" physical design cleverly decomposes one driving input into two distinctive motion modes, and a single flexible driver can realize the natural transition from smooth arc motion to local rolling deformation.

[0109] Embodiment three

[0110] The present embodiment provides a bionic mouth lip motion control device with multi-driver bionic layout and perception closed-loop cooperative control.

[0111] In order to construct a complete oral lip expression system capable of expressing rich emotions, the present embodiment adopts bionics principle for multi-driver layout. In the perioral area, multiple flexible electric actuators are arranged following the anatomical position and function of the human facial expression muscle. For example, the electric actuator located above the corners of the mouth accurately simulates the "levator labii superioris muscle", and the fibers in the integrated fiber reinforcement layer are arranged obliquely inward and upward along the muscle fiber direction; some electric actuators arranged around the oral fissure simulate the "orbicularis oris muscle" and adopt ring-shaped or local arc-shaped fiber arrangement to guide the contraction deformation.

[0112] Each flexible electro-actuator serves as both an effector and a sensor. Its internally integrated flexible strain sensor can sense its own stretching and shrinking in real time. When the controller receives an instruction like "laughing", instead of simply sending a fixed voltage to all relevant drivers, it activates the "zygomaticus major" analog driver, the "risorius" analog driver and the "risus" area driver synchronously and cooperatively according to the bionic motion model. During the motion, the strain sensors on each driver provide real-time feedback, forming a closed-loop control. The controller dynamically fine-tunes the voltage of each driver, accurately coordinating the timing, amplitude and rate of its contraction. For example, the powerful contraction of the driver dominates the large upward movement of the mouth corner, while at the end of the contraction, the driver, due to its specific bionic installation angle and fiber constraint, produces a combination of pulling and squeezing effect on the soft tissues of the upper lip outside and the cheek, thus inducing natural nasolabial groove lines and apple muscle bulge effect on the bionic skin surface. This control strategy based on anatomical bionic layout, multi-driver cooperative excitation and proprioceptive closed-loop feedback realizes the dynamic cooperative driving of macroscopic mouth shape change to microscopic skin texture, greatly improving the liveliness, emotional expressiveness and individualized features of the robot's expression.

[0113] Embodiment Four

[0114] The embodiment provides a ring-shaped lip driving unit based on a reticular constraint guide, and specifically provides a driving unit specially used for simulating the ring-shaped contraction function of the orbicularis oris muscle, and the core of the driving unit is to combine a flexible electrode and an anisotropic constraint structure into one, to form a composite functional layer.

[0115] The driving unit is in the form of a long and thin sheet, and the total thickness is about 0.5 mm, and the driving unit comprises the following layered structures in sequence:

[0116] The driving layer is an acrylic dielectric elastomer film, which is pre-stretched to 300% of the original area.

[0117] The composite functional layer is located on the upper and lower surfaces of the driving layer. The layer is a silver-polyurethane composite grid formed on a polyimide flexible base film through nano-imprinting and laser direct writing technology. The composite functional layer is provided in the form of a grid, and specifically as follows:

[0118] In the direction of the long axis of the unit (the predetermined driving direction): the grid is in the form of a sparse long rhombus, and the equivalent tensile stiffness in this direction is relatively low (about 2 MPa), allowing the material to stretch or contract to a large extent.

[0119] In the direction of the short axis of the unit (the direction that needs to be suppressed): the grid is in the form of a dense short wavy shape, and the equivalent tensile stiffness in this direction is extremely high (>50 MPa), strongly suppressing the expansion of the material in this direction.

[0120] This composite functional layer assumes the dual role of applying the driving electric field (as an electrode) and providing anisotropic mechanical constraint.

[0121] Under the above structure, multiple such driving units are arranged in a local annular or arc shape along the edge of the oral fissure, simulating different functional segments of the orbicularis oris muscle. When a driving electric field is applied to a certain driving unit, the driving layer attempts to isotropically expand in-plane due to Maxwell stress. Due to the high stiffness constraint of the composite functional layer in the short axis direction, the expansion is strongly suppressed; while under the low stiffness constraint in the long axis direction, the driving layer is allowed to significantly contract in that direction. When both ends (fixed end and free end) of the driving unit are anchored, this contraction translates into a linear driving force that pulls the functional part of the lip (such as the lip edge) towards the center. By coordinated control of multiple annularly arranged driving units, uniform contraction of the lips, pursing of the lips (overall protrusion), and other complex sphincter-like movements can be achieved, highly simulating the natural biomechanical properties of the orbicularis oris muscle.

[0122] The electrode is integrated with the constraint layer, the structure is extremely compact, and it is suitable for high-density arrangement around the lips. Through grid pattern programming, precise deformation guidance in any direction can be achieved, especially suitable for reproducing the annular muscle fiber orientation of the orbicularis oris muscle. Due to the extremely thin constraint layer, the required driving electric field strength is relatively low, improving the safety of the system.

[0123] Example Five

[0124] This embodiment provides a driving module that simulates the coordinated work of multiple oral perioral expression muscles, using "linear driving fiber bundles" as the basic driving unit, with the following specific structure:

[0125] Flexible bearing substrate: A silicone substrate is used that conforms to the surface of the robot's mandible and cheek, with pre-set anchor points corresponding to the anatomical structure (such as the attachment points of the subcutaneous tissue corresponding to the zygomatic bone, mandibular margin, and oral commissure).

[0126] Driving fiber bundle: A plurality of "driving fiber bundles" are prepared, with a diameter of about 1.2 mm and a length customized according to the distance between the origin and termination points of the muscle. The core of each fiber bundle is an ionomer-metal composite material wire, wrapped with a spiral carbon nanotube electrode, and the outermost layer is a constraint guide sheath layer woven at an angle of ±20°.

[0127] Bionic arrangement: multiple driving fiber bundles are arranged and fixed on the substrate according to the physiological orientation of the target muscle:

[0128] Zygomaticus major muscle simulation bundle: from the zygomatic bone obliquely downward and inward to the oral commissure, responsible for lifting the oral commissure (smiling).

[0129] Depressor anguli oris muscle simulation bundle: from the mandible obliquely upward and inward to the oral commissure, responsible for lowering the oral commissure (sorrow).

[0130] Zygomaticus major simulation bundle: nearly vertical distribution above the upper lip, responsible for lifting the middle of the upper lip.

[0131] Orbicularis oris simulation segment bundle: shorter fiber bundles are arranged in a segmented manner around the oral fissure to achieve lip closure.

[0132] Based on the above structure, each driving fiber bundle is independently controllable. When making a "laughing" expression, the controller synchronously activates the zygomaticus major simulation bundle and the levator labii superioris simulation bundle, and is assisted by the appropriate relaxation of the upper segment bundle of the orbicularis oris. The contraction of the driving fiber bundle is directly transmitted to the corresponding connection point of the lip function part through the flexible anchor interface at the end, producing coordinated and multidirectional displacement, thereby forming a natural laughing posture. Due to the linear form and high flexibility of the fiber bundle, they can closely fit the complex facial surface, achieving a highly bionic mechanical transmission path.

[0133] Example six

[0134] This embodiment provides a device that integrates magnetic detachable connection and state sensing for lip skin assembly, with the following specific structure:

[0135] 1. Magnetic connection structure:

[0136] Drive module side: On the surface of the drive module (carrier), neodymium-iron-boron permanent magnet micro-particles wrapped in flexible silicone are embedded through in-mold injection, forming a specific array pattern (such as a closed-loop array around the oral fissure).

[0137] Lip function part (skin) side: On the inside of the silicone bionic lip skin, a complementary pattern composed of soft magnetic silicone (mixed with carbonyl iron powder) is formed through silk screen printing or patch embedding technology.

[0138] Connection and positioning: With the help of magnetic force, the lip skin can be quickly and accurately adsorbed to the drive module without the need for glue or mechanical fastening. At the same time, the physical buckle around the module and the magnetic array work together to ensure that the skin does not slip during intense expression movements.

[0139] 2. Connection state sensing and safety control:

[0140] Micro Hall sensors are integrated at key positions of the magnetic array (such as the four corners).

[0141] When the skin is properly fitted, the Hall sensor detects a specific stable magnetic flux. If the skin is accidentally lifted or not installed in place, the magnetic flux changes significantly.

[0142] The signal of the Hall sensor is connected to a controller. Once the connection anomaly is detected, the controller can immediately execute a safety strategy: ① reduce or cut off the driving electric field to prevent the driver from being damaged or generating uncontrollable movement under no load; ② issue a maintenance alarm through the voice of the robot or an indicator light. This achieves closed-loop perception and control of the physical state of “connection”, greatly improving the reliability and safety of the system.

[0143] The embodiment of the present application also provides a bionic robot lip movement control method, which can be applied to the bionic robot lip movement control device provided by any embodiment of the present application, and will be specifically described below with reference to the drawings.

[0144] Figure 8 The bionic robot lip movement control method provided by an embodiment of the present application is shown in the flowchart.

[0145] Referring to Figure 8 The method can include the following steps:

[0146] S1: receiving a target lip expression instruction.

[0147] S2: analyzing the target lip expression instruction into a cooperative driving signal for the plurality of flexible electric actuators according to a pre-stored expression and driving mapping relationship.

[0148] S3: based on the cooperative driving signal, controlling each flexible electric actuator to generate a driving displacement or deformation under the guidance of the passive constraint structure, so as to cooperatively drive the lip function part to generate a composite lip deformation matched with the target expression.

[0149] Regarding S1:

[0150] The controller receives a “target lip expression instruction” sent from an external upstream system (such as a higher-level expression decision module, a user interaction interface, or a preset program) through its integrated communication interface (such as UART, SPI, I2C, or a wireless module). The instruction carries the specific expression type (such as “smile”, “surprise”, or “pout”) and its possible dynamic parameters (such as intensity, speed) of the intended expression, and its data format can be a pre-defined expression code, a sequence of target feature point coordinates, or a parameter vector of the driving signal. The instruction analysis firmware or software embedded in the controller captures and verifies the instruction data in real time, temporarily stores it in the internal register or buffer, and provides a clear and processable control target for the subsequent instruction analysis and signal mapping steps. This step technically defines the boundary of human-computer interaction or autonomous decision-making, converts the abstract “expression intention” into a digital command recognizable and processable by the controller, and is the fundamental prerequisite for the entire closed-loop control system to start and run towards the correct target. The corresponding beneficial effects are to realize the standardization, programmability, and real-time response of the control instruction, and to provide an accurate input reference for the subsequent high-fidelity expression reproduction.

[0151] Regarding S2:

[0152] The controller accesses its internally pre-stored "expression-driving mapping relationship" database or mathematical model. The mapping relationship is pre-established through computational simulation or experimental calibration based on the specific physical structure of the device (such as the bionic spatial arrangement of flexible electric actuators, the guiding characteristics of passive constraint structures, and the mechanical response of the lip function part), which defines the corresponding relationship between each target expression (or its characteristic parameters) and a set of driving signal parameters. The analysis process is that the controller queries and calculates the mapping relationship according to the expression type and dynamic parameters specified by the received "target lip expression instruction", thereby generating a set of initial driving signals (such as voltage pulse sequences of specific waveforms) for the multiple flexible electric actuators, which are optimized in time sequence (such as excitation timing, duration), spatial distribution (such as activation combination of different drivers), and intensity (such as driving voltage amplitude). This step technically completes the accurate decoding from high-level, abstract expression semantics to low-level, specific physical driving instructions, and its corresponding beneficial effect is that it realizes efficient planning and output of complex collaborative driving tasks through pre-set intelligent mapping with strong coupling with hardware characteristics, provides accurate and directly executable collaborative control benchmarks for subsequent execution links, and is the key algorithm guarantee to ensure expression reproduction fidelity and naturalness.

[0153] Regarding S3:

[0154] The controller applies the collaborative driving signals (such as voltage sequences with specific timing and amplitude) generated by the analysis to the corresponding multiple flexible electric actuators. Each electric actuator produces active deformation under electric field excitation, but this deformation is immediately guided by the passive constraint structure, and the movement of the free end is forced to be limited to the preset direction or trajectory consistent with the physiological path of the target muscle group, thereby converting the active deformation of the material into driving displacement or deformation with a specific vector. These precisely directed, spatially and temporally collaborative discrete driving actions are transmitted synchronously or asynchronously by the free ends to the continuous lip function part, forming a complex dynamic stress field on its surface and inside. As a carrier of mechanical integration and morphological transformation, the lip function part couples, superimposes and smoothly transitions these discrete inputs, and finally emerges a global, continuous and dynamically evolving composite lip deformation that accurately matches the complex geometric shape and motion details required by the target expression. Starting from the complete link of "electric signal-mechanical movement-morphological synthesis", this step realizes the lossless and high-fidelity conversion of digital instructions into highly personified physical expressions, and its core beneficial effect is to ensure the high coordination, morphological accuracy and dynamic naturalness of the output motion of the entire driving system, fundamentally overcoming the defects of traditional solutions such as stiff action and poor coordination.

[0155] The bionic robot lip movement control method provided in the application is described in detail through several embodiments.

[0156] Example Seven

[0157] The embodiment provides a humanization closed-loop cooperative control method of lip expression.

[0158] Instruction receiving and analysis: receive the "pouting" instruction. The controller queries the mapping database and analyzes it as: all driving units in the orbicularis oris muscle area contract (target deformation 30%), the depressor anguli oris muscle unit is slightly inhibited (target deformation -5%), and the time sequence is to reach the peak within 300 ms and maintain.

[0159] Injection of humanization parameters: add biological characteristics to the above driving signal:

[0160] Start-up delay: the activation signal of each unit is delayed for 10-50 ms (simulating the difference in nerve conduction).

[0161] Relaxation characteristics: after the peak, the control signal is slightly attenuated in an exponential curve (simulating the viscoelastic relaxation of muscles).

[0162] Micro-jitter: superimpose a random fluctuation of 8-12 Hz and amplitude <1%.

[0163] Cooperative driving and real-time sensing: the controller sends the driving signal with parameters to each unit. At the same time, the strain sensor feeds back the actual deformation in real time, and the optical sensor feeds back the displacement of the mouth angle.

[0164] Dynamic closed-loop adjustment: the local PID controller compares the target and actual deformation to quickly fine-tune the voltage. The central controller compares the displacement of the optical sensor feedback with the expected (such as symmetry), and if it finds that the asymmetry is caused by mechanical coupling, it dynamically fine-tunes the signal strength of the left and right driving units to achieve cross-unit cooperative closed-loop.

[0165] Fatigue simulation: if the "pouting" expression needs to be maintained for more than 10 seconds, the controller slowly reduces the driving electric field by about 5% according to the "fatigue attenuation coefficient", so that the lips produce subtle relaxation, greatly enhancing the sense of realism.

[0166] Through the above method, the lip expression is no longer a simple open-loop displacement superposition of multiple drivers, but has the timing characteristics, dynamic fluency, micro-uncertainty and fatigue of biological movement, thereby realizing the essential leap from "mechanical movement" to "natural expression".

[0167] Example Eight

[0168] The bionic robot lip movement control method provided in the embodiment includes the following steps:

[0169] S11: Receive lip motion instruction. The instruction can be derived from preset program, voice recognition, visual capture or remote control.

[0170] S12: Instruction analysis and drive mapping. The controller determines the target set of flexible electro-actuators to be activated, as well as the required drive displacement amount, deformation mode (e.g. linear contraction or end flipping) and timing parameters for each target driver, according to the instruction, by querying the preset expression-driver mapping database or running the neural network model.

[0171] S13: Apply drive electric field and guide deformation. The controller applies the calculated drive electric field sequence to the electrode layer of the target driver. The active deformation of the flexible electro-actuator under the electric field is immediately guided by its passive constraint structure (fiber reinforced layer and / or constraint guide rail). For the device of embodiment 2, this step specifically includes controlling the drive electric field so that the electro-actuator sequentially undergoes the first stage of deformation (path following) constrained by the limiting slide and the second stage of deformation (free rolling) after breaking away from the constraint.

[0172] S14: Drive the lip function part to produce expressions. The guided and transformed drive displacement is transmitted to the lip function part (bionic skin) through the free end of the driver, making it produce the expected and compliant deformation, completing complex expressions such as smiling, pursing the lips, and being surprised.

[0173] S15 (optional): Closed-loop feedback and precise adjustment. If the system integrates deformation sensors (e.g. embodiment 3), the key point displacement of the lip function part or the deformation amount of the driver itself is monitored in real time, and the data is fed back to the controller. The controller compares the feedback signal with the target model and dynamically adjusts the drive electric field using PID, adaptive control and other algorithms to achieve high-precision and high-robustness closed-loop expression control.

[0174] Embodiment Nine

[0175] This embodiment provides a bionic robot whose head is equipped with a bionic robot lip motion control device as described in any of the above embodiments. The device is integrated as a whole on the robot's facial skeleton (carrier) and covered with highly simulated silicone skin (lip function part). The main controller or dedicated expression control module inside the robot runs the control method as described in embodiment 4. By receiving information from environmental perception modules (such as cameras, microphones) or directly executing instructions from emotion computing modules, the robot can generate highly humanized, natural and smooth, and emotionally expressive lip expressions in real time, significantly improving its human-machine interaction realism, affinity and emotional resonance ability in social, service, and companionship scenarios.

[0176] Embodiment Ten

[0177] This embodiment integrates the previous examples to demonstrate a complete bionic robot lip control system integration scheme.

[0178] On the robot head skeleton, the perioral area is divided into multiple functional subareas: upper lip area, lower lip area, left / right corner area, cheek area. Each subarea adopts the most suitable driving scheme:

[0179] Upper / lower lip: adopt the mesh constraint driving unit of embodiment 4 to achieve fine lip shape control and closure.

[0180] Corner and cheek area: adopt the linear driving fiber bundle module of embodiment 5 to provide strong lifting and pulling torque.

[0181] Overall assembly: all driving modules are connected to the final bionic silicone lip skin through the magnetic interface of embodiment 6.

[0182] Control system: unified scheduling by the anthropomorphic closed-loop cooperative control method of embodiment 7.

[0183] When the robot needs to complete a complex "smiling with a sip" expression, the system works cooperatively: the corner fiber bundle is lifted, the lower lip mesh unit is slightly retracted and rolled inward, the upper lip mesh unit maintains moderate tension, and all control signals are injected with anthropomorphic dynamic parameters. The final expression not only has accurate movements, but also has vividness and emotional tension that is difficult to describe, marking a new height in practicality and high performance of the technical scheme of the present application.

[0184] In summary, this scheme achieves closed-loop optimization of traditional schemes by bionic arrangement and cooperative control of flexible electro-actuators: its "silent driving" feature fundamentally eliminates mechanical noise and vibration, greatly improving the realism and immersion of the interaction; the combination of "bionic layout" and "constraint guidance" enables the perioral movement to be upgraded from mechanical linear displacement to anthropomorphic multi-mode composite deformation, successfully simulating the subtle dynamics and rich levels of human expressions; "structural integration" and "perception closed-loop" solve the core contradiction between space occupation and accurate control of rigid schemes. Ultimately, this scheme enables the bionic robot's lip expression to achieve a qualitative leap in naturalness, expressiveness, and user experience, providing key technical support for building the next generation of bionic robots that can interact with humans in an emotional and immersive way.

[0185] The technical scheme of the present application can achieve the following technical effects:

[0186] 1. High anthropomorphism and natural expression: through bionic spatial arrangement and cooperative driving according to perioral expression muscle dissection, combined with the precise guidance of passive constraint structure to deformation, it can reproduce the delicate, smooth and richly layered composite deformation of human lips, solving the fundamental problem of rigid driving expression being stiff and unnatural.

[0187] 2. Compact structure and deep integration: The flexible electric actuator itself is thin and light, and the passive constraint structure can be highly integrated (such as a composite functional layer or a micro guide), eliminating the need for a complex rigid transmission chain, so that a multi-degree-of-freedom driving system can closely match the complex curved surface layout of the face, achieving high-density functional integration in limited space.

[0188] 3. Silent driving and experience optimization: Based on the principle of electric field actuation, the driver has no mechanical movement component noise and vibration during operation, providing a quiet and comfortable immersive experience for human-machine close-range interaction.

[0189] 4. Precise control and intelligent closed loop: By integrating deformation sensing and closed-loop control, the driving process can be monitored and precisely controlled in real time to ensure high fidelity and consistency of composite lip deformation, and by injecting anthropomorphic dynamic parameters (such as start delay, micro-vibration, fatigue simulation), the expression can be more biologically realistic and emotionally expressive.

[0190] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A device for controlling the movement of the lips of a bionic head, characterized in that it comprises: Comprise: a carrier; a lip function part; a plurality of flexible electric actuators comprising an electrically actuated material capable of active deformation under electric field excitation, and being arranged in a biomimetic space based on the anatomical position and muscle fiber orientation of the target perioral expression muscle, one end of which is connected to the carrier as a fixed end, and the other end is connected to the lip function part as a free end, the flexible electric actuator comprises a driving layer, a first flexible electrode layer and a second flexible electrode layer arranged in layers; the driving layer is composed of the electrically actuated material, and the first flexible electrode layer and the second flexible electrode layer are respectively arranged on both sides of the driving layer to apply a driving electric field; and a passive constraint structure comprising a constraint guide provided on the carrier, the constraint guide having an extension trajectory matching the physiological motion arc of the target expression muscle, at least a part of the flexible electric actuator cooperating with the constraint guide to constrain the deformation path of the flexible electric actuator; wherein the passive constraint structure is coupled to the flexible electric actuator or the driving layer; the passive constraint structure; configured to provide anisotropic mechanical constraint to the active deformation of the flexible electric actuator, thereby guiding and converting the active deformation into driving displacement or deformation along a first preset direction; wherein the flexible electric actuator is configured to generate driving displacement or deformation guided by the passive constraint structure at its free end, to cooperatively drive the lip function part to generate a composite lip deformation matching the target expression.

2. The apparatus of claim 1, wherein, The target perioral expression muscle is selected from at least one of the following: orbicularis oris muscle, levator anguli oris muscle, depressor anguli oris muscle, levator labii superioris muscle, mentalis muscle, zygomaticus major muscle, risorius muscle, depressor labii inferioris muscle, buccinator muscle; The angle between the arrangement direction of the flexible electric actuator and the main orientation of the muscle fiber of the target expression muscle it simulates is less than 45 degrees.

3. The apparatus of claim 1, wherein, The passive constraint structure is a structure with anisotropic rigidity, which comprises at least one of the following: a net structure constraint layer, which is configured to have an equivalent tensile stiffness in the first preset direction lower than that in at least one other direction; a sheet-shaped intrinsic anisotropic material layer, which is configured to have a Young's modulus in the first preset direction lower than that in at least one other direction; discrete rigid constraint elements, which are distributed in a chain or strip shape along the first preset direction, thereby forming a continuous constraint path in a direction perpendicular to the first preset direction.

4. The apparatus of claim 3, wherein, The net structure constraint layer is a fiber reinforced layer comprising reinforced fibers arranged in a second preset direction.

5. The apparatus of claim 3, wherein, The passive constraint structure is integrated with the first flexible electrode layer and / or the second flexible electrode layer to form a composite functional layer with both conductive function and anisotropic constraint function.

6. The apparatus of claim 1, wherein, The constraint guide is a rigid constraint groove provided with a limiting slide; wherein the free end of the flexible electric actuator or the transmission component connected thereto slidably cooperates with the limiting slide, and the flexible electric actuator sequentially undergoes a first stage path movement constrained by the limiting slide and a second stage deformation after reaching the limiting end under the excitation of the driving electric field.

7. The apparatus of claim 6, wherein, The flexible electric actuator is configured to: In the first stage path movement, the flexible electric actuator is constrained by the limiting slide rail, and linear expansion movement along a preset track is generated; In the second stage deformation, after the free end or the transmission part moves to the limiting end, the flexible electric actuator, the adjacent flexible electric actuator and the lip function part are coupled to cause local nonlinear composite deformation.

8. The apparatus of claim 1, wherein, Further comprising a controller electrically connected with the flexible electric actuator, used for performing cooperative closed-loop control on the flexible electric actuator according to target lip action instructions and deformation information of the flexible electric actuator, so as to realize the composite lip deformation.

9. A method for controlling lip motion of a bionic talking head, characterized in that, The method is applied to the device as claimed in any one of claims 1 to 8, and the method comprises: receiving target lip expression instructions; analyzing the target lip expression instructions into cooperative driving signals of the plurality of flexible electric actuators according to a pre-stored expression and driving mapping relationship; controlling each flexible electric actuator to generate driving displacement or deformation under the guidance of the passive constraint structure, so as to cooperatively drive the lip function part to generate composite lip deformation matched with the target expression based on the cooperative driving signals.

10. A biomimetic robot, characterized in that, The device comprises a head and a bionic robot lip movement control device as claimed in any one of claims 1 to 8, and the device is installed on the head.

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