Bionic pupil-iris linkage device based on flexible driving body and control method

Abstract

The application discloses a kind of bionic pupil iris linkage device and control method based on flexible drive body, belong to bionic robot interactive technical field.Device includes outer frame fixed ring, annular flexible drive body and iris bionic layer.Flexible drive body outer edge is fixed, inner edge is free, under the action of driving signal, it generates radial in-plane deformation, so that central hole diameter continuously changes to simulate pupil zoom;Iris bionic layer is supported on the surface of drive body, with drive body share the same continuous deformation field, utilize the radial strain gradient formed by outer edge fixed inner edge free, make the difference of iris line deformation from outside to inside, simulate the biomechanical characteristics of real human eye iris when pupil changes.Control method includes target diameter determination, hysteresis compensation, closed-loop correction and asymmetric time constant dynamic smoothing, so that pupil reduces faster than amplification.The application can realize the natural coupling of pupil and iris without independent texture driving mechanism, and is suitable for high anthropomorphic emotional interactive robot eyeball system.

Description

Technical Field

[0001] This invention relates to the field of bionic robot human-computer interaction and flexible actuation device technology, specifically a bionic pupil-iris linkage device and control method based on a flexible actuator. Background Technology

[0002] In the field of biomimetic emotional interaction robots, the eyes are key facial organs for conveying emotional states and attracting human attention. The contraction and dilation of the pupils not only reflect physiological adaptation to ambient light but also serve as an important visual window for robots to express inner states such as excitement, fear, curiosity, and relaxation. To achieve a highly human-like interactive experience, the robot's eyes not only need precise control over the changes in pupil diameter but also need to simultaneously present the natural deformation of the iris texture during stretching or compression—this natural physical coupling between "pupil size changes" and "iris texture changes" is the core factor determining the realism and lifelikeness of the robot's gaze.

[0003] However, existing solutions for realizing the pupil of a bionic robot's eye generally have the following shortcomings: First, while OLED or LCD displays can virtually render arbitrary pupil patterns, the lack of physical surface depth and natural gloss results in a noticeable "screen-like" and "flat" appearance during close-range human-computer interaction, severely weakening the biomimetic realism. Second, mechanical aperture solutions rely on the mechanical movement of metal or rigid aperture blades, which not only exhibit blade gaps and discontinuous, stepped changes but also completely lack iris texture, resulting in a stiff appearance that differs significantly from the real human eye. Third, some solutions in recent years have applied flexible actuators (such as dielectric elastomers) to variable apertures, but these solutions are designed primarily for controlling the light transmission of the optical system. Their actuator structures and performance evaluation indicators are geared towards image quality, rather than the needs of biomimetic appearance and emotional interaction, thus failing to solve the problem of realism in biomimetic appearance.

[0004] While existing technologies (such as CN101745227A) mention using elastic membranes and deformable elements to achieve pupil dilation and contraction, their iris surface layer is merely a simple "color block" or "staining layer." Its deformation mode is overall isotropic stretching or simple scaling, lacking the non-uniform gradient characteristics of the iris in the real human eye, where the inner edge deforms drastically while the outer edge deforms minimally or even statically. Furthermore, the pupil changes and iris texture changes in these existing solutions are essentially byproducts of the same uniform deformation. They do not recognize or utilize "radial strain gradients" to simulate the biomechanical properties of the real iris, nor do they address how to differentiate the degree of local deformation of the fine iris textures (such as radial fibers and crypts) through deformation field distribution.

[0005] In summary, the existing technology lacks a biomimetic device that can make pupil size changes and iris texture differential deformation share the same physical process, and that the deformation process exhibits a non-uniform gradient distribution in the radial direction consistent with that of a real human eye. Summary of the Invention

[0006] The purpose of this invention is to provide a biomimetic pupil-iris linkage device and control method based on a flexible actuator. This device aims to solve the technical problems in existing solutions where pupil changes and iris texture changes are independent of each other, lack natural physical coupling, and the iris deformation pattern does not conform to the biomechanical gradient characteristics of the real human eye.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a bionic pupil-iris linkage device based on a flexible actuator, installed in the eye system of a bionic emotional interaction robot, comprising an outer frame fixing ring, a ring-shaped flexible actuator, and an iris bionic layer.

[0008] The outer frame fixing ring is a ring-shaped rigid support structure used to provide installation reference and outer edge constraint.

[0009] The outer edge of the annular flexible actuator is fixed to the outer frame fixing ring, while the inner edge is free and unrestrained. The annular flexible actuator can generate radial in-plane deformation under the action of the driving signal, so that its central aperture changes continuously to simulate the diameter change of a biological pupil.

[0010] The iris bionic layer is supported on at least one surface of the annular flexible actuator, or is integrated with the annular flexible actuator; the iris bionic layer and the annular flexible actuator share the same continuous deformation field.

[0011] Based on the boundary constraint condition of fixed outer edge and free inner edge, when the annular flexible drive body generates radial in-plane deformation, it will naturally form a radial strain gradient that increases from the outer edge to the inner edge; correspondingly, the texture deformation of the iris bionic layer also shows a gradient distribution that increases from the outer edge to the inner edge, so that the change in pupil diameter and the visual change in iris texture are synchronously and naturally coupled.

[0012] Furthermore, the annular flexible actuator is selected from any one of dielectric elastomers, liquid crystal elastomers, thermally responsive elastomers, electrothermal elastomers, magnetically responsive elastomers, pneumatic elastomers, or hydraulic elastomers, all of which can provide continuous in-plane strain to drive aperture changes.

[0013] Furthermore, when the annular flexible drive body is a dielectric elastomer, an acrylate elastomer film or a silicone rubber-based elastomer film that has undergone pre-stretching and thinning treatment is used, and flexible conductive electrode layers are provided on its upper and lower surfaces; when a driving voltage is applied between the upper and lower electrode layers, Maxwell stress causes the dielectric elastomer to compress in the thickness direction, which, based on the near-incompressible property of the elastomer material, is transformed into in-plane radial expansion deformation, driving the central aperture to expand.

[0014] Furthermore, when the annular flexible actuator is a liquid crystal elastomer, a thin film structure with pre-programmed liquid crystal orientation is adopted, which can generate anisotropic deformation under heat, light, or electric field excitation, drive the inner edge to generate radial displacement, thereby adjusting the size of the central pupil aperture.

[0015] Furthermore, the iris biomimetic layer can be formed by one or more of the following methods: flexible ink printing, flexible thin film transfer, multilayer elastic coating, micro-nano structure color preparation, direct coloring of the substrate surface, or laser microtexturing; the elastic modulus of the iris biomimetic layer is not higher than 3 times the elastic modulus of the annular flexible actuator, so as to avoid significantly restricting the deformation of the actuator and ensure that the texture can deform synchronously with the actuator.

[0016] Furthermore, the iris biomimetic layer is provided with non-uniformly distributed radial biomimetic textures, which include one or more combinations of radial fibers, color spots, and crypts; and the texture density or color depth of the inner edge region differs from that of the outer edge region, so that the local deformation presents a visually differentiated effect, further enhancing the biomimetic realism.

[0017] Furthermore, the iris bionic layer remains optically transparent in the central pupil region, allowing the bottom optical elements to perform optical framing through this central transparent region; the outer frame fixing ring can also serve as the electrode lead substrate of the annular flexible drive body or the mounting reference for the overall structure.

[0018] This invention also provides a control method for the above-mentioned biomimetic pupil-iris linkage device based on a flexible actuator, comprising the following steps: 1. Target pupil diameter determination: Receive emotional state signals from the robot's cognitive system and / or ambient light sensor signals, and determine the target pupil diameter according to a preset mapping relationship.

[0019] 2. Driving signal generation and hysteresis compensation: The driving signal is generated based on the driving signal-displacement model of the ring flexible actuator, and the driving signal is fed forward to compensate by an inverse hysteresis model in order to overcome the inherent hysteresis characteristics of the flexible actuator.

[0020] 3. Drive signal output: The compensated drive signal is applied to the annular flexible drive body to drive it to generate the corresponding deformation.

[0021] 4. Dynamic smoothing: Apply dynamic smoothing with an asymmetric time constant to the driving signal so that the response speed of the pupil constriction process is faster than that of the pupil dilation process, in order to simulate the asymmetric time characteristics of pupil changes in the real human eye.

[0022] Furthermore, the control method also includes a closed-loop feedback correction step: obtaining the current deformation state and the actual pupil diameter through an external detection device and / or a flexible actuator self-sensing method, and performing closed-loop control correction on the drive signal accordingly; The external detection device is selected from a camera, an optical sensor, or a displacement sensor; the self-sensing is based on the deformation calculated from changes in one or more electrical parameters of the flexible actuator, such as capacitance, charge, current, impedance, or resistance.

[0023] Furthermore, the inverse hysteresis model adopts the Prandtl-Ishlinskii inverse model or the Preisach inverse model to perform nonlinear compensation on the driving signal, so as to ensure the linearity of the pupil diameter change and the positioning accuracy.

[0024] Compared with existing technologies, this biomimetic pupil-iris linkage device and control method based on a flexible actuator constructs a shared continuous deformation field with increasing strain from the outer edge to the inner edge, enabling the differential deformation of pupil dilation and iris fine texture to be realized synchronously on a single physical structure. This provides a highly realistic means of eye expression for biomimetic emotional interaction robots. Specific beneficial effects of this invention include: 1. Natural coupling between pupil and iris: The iris bionic layer and the pupil aperture share the continuous deformation field of the flexible actuator, which can realize the synchronous and natural presentation of changes in pupil size and iris texture without the need for an independent texture driving mechanism.

[0025] 2. Biomimetic Strain Gradient: The boundary condition of a fixed outer edge and a free inner edge naturally forms a radial strain gradient, with the inner edge deforming more than the outer edge, consistent with the biomechanical characteristics of the iris muscle in the real human eye. This gradient deformation characteristic makes the fine textures (such as radial fibers) of the inner edge of the iris stretched or compressed to a significantly greater degree than the outer edge, giving it a biomimetic realism that is not available in existing technologies.

[0026] 3. Physical Realism: The pupil and iris changes are realized through continuous deformation of the actual physical structure. It has a three-dimensional depth and natural gloss under any viewing angle and lighting conditions, avoiding the "screen feel" and "flat feel" of screen rendering solutions.

[0027] 4. Flexible material selection: The core invention concept is decoupled from the specific flexible driving material, and suitable flexible functional materials can be selected according to performance requirements.

[0028] 5. Dedicated control for flexible actuators: By using hysteresis compensation, closed-loop feedback, and asymmetric time constant control, the accuracy and naturalness of pupil changes are improved, making the dynamic contraction and dilation rhythm of the pupil (fast contraction and slow expansion) highly consistent with the real human eye.

[0029] 6. Compact structure and low power consumption: The annular thin-film structure has a small effective area, making it suitable for installation within the space-constrained eye cavity of robots. The differentiated deformation of the iris texture is achieved entirely passively through strain gradient, eliminating the need for a separate texture driving mechanism, thus significantly reducing system complexity and power consumption. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention; Figure 2 This is a schematic diagram of the working process of the present invention; Figure 3 This is the control flowchart of the present invention.

[0031] In the figure: 101, outer frame fixing ring; 102, ring-shaped flexible drive body; 103, iris bionic layer; 104, pupil area. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see Figures 1-3 The present invention provides the following technical solutions: A biomimetic pupil-iris linkage device and control method based on a flexible actuator 1. Overall Structure of the Device The biomimetic pupil-iris linkage device provided by this invention includes the following components: Outer frame fixing ring 101: a ring-shaped rigid support structure that provides a fixed constraint on the outer edge of the flexible drive body. The outer diameter can be set according to the size of the target eyeball, preferably 11mm to 14mm.

[0034] The annular flexible actuator 102 has its outer edge fixed to the outer frame fixing ring 101, while its inner edge is free and unrestrained. Under the action of the driving signal, it generates radial in-plane deformation, causing the central aperture (i.e., the pupil region 104) to continuously expand or shrink.

[0035] Iris biomimetic layer 103: Supported on at least one surface of the flexible actuator or integrated with the flexible actuator, and has a biomimetic iris texture. During the radial deformation of the flexible actuator, the texture of the iris biomimetic layer 103 undergoes continuous visual changes along the radial direction to simulate the morphological changes of the biological iris during pupil changes.

[0036] Drive circuit: Apply a controllable drive signal to the flexible actuator to achieve continuous adjustment of the pupil diameter.

[0037] like Figure 1 As shown, the overall structural diagram of the device is a cross-sectional / layered schematic diagram; The iris bionic layer 103 is stretched / compressed synchronously with deformation, and the texture changes continuously along the radial direction. The annular flexible drive body 102 generates in-plane radial deformation, with the outer edge fixed and the inner edge free; The outer frame fixing ring 101 fixes the outer edge of the drive body and provides support and electrode lead-out; The diameter of the pupil region is variable (104). Note: The three-layer structure shares a continuous deformation field.

[0038] 2. Core Inventive Concept The core of this invention lies in using a flexible actuator as both a motion execution element and an iris bionic carrier, so that the iris texture and the pupil aperture share the same continuous deformation field.

[0039] Specifically: The flexible actuator generates radial in-plane strain under the driving signal; The iris bionic layer 103 is supported in the deformation field, and its texture (such as radial fibers, gradient colors, crypts, etc.) deforms synchronously with the local strain of the flexible actuator. Due to the boundary condition of a fixed outer edge and a free inner edge, the radial strain increases from the outer edge to the inner edge, forming a non-uniform strain gradient—which precisely simulates the biological characteristic of the inner edge of the iris being stretched / compressed more while the outer edge remains almost still in the human eye.

[0040] Through this "functional decoupling and deformation sharing" design, a highly biomimetic iris visual effect can be achieved without a separate texture driving mechanism.

[0041] 3. Ring-shaped flexible actuator 102 The annular flexible actuator 102 is the motion execution element of this invention, simulating the mechanical function of the iris muscle in the human eye. It is selected from flexible functional materials capable of generating continuous strain within the thin film surface, including but not limited to: Dielectric elastomer actuator (DEA): When a high-voltage electric field is applied between the upper and lower electrodes, Maxwell stress causes compression in the thickness direction, leading to in-plane expansion due to the material's near-incompressibility. Materials are selected from acrylate elastomers (such as the VHB series), silicone rubber-based elastomers, etc.

[0042] Liquid crystal elastomer (LCE): By pre-programming liquid crystal orientation to obtain the expected circumferential or radial strain mode, it produces anisotropic deformation under the action of heat, light, or electric field, causing radial displacement of the inner edge.

[0043] Thermally responsive elastomers or electrothermal elastomers: These elastomers generate thermal expansion and deformation by embedding heating elements or by conducting electricity within the body.

[0044] Pneumatic or hydraulic elastomers: drive radial deformation of annular films by inflating or filling cavities with air or liquid.

[0045] Magnetic-responsive elastomers: Elastomers that undergo in-plane deformation when subjected to an external magnetic field with embedded magnetic particles.

[0046] The radial displacement capability of the flexible actuator should be at least 2 mm to ensure that the pupil diameter has a sufficiently continuous range of variation.

[0047] 4. Iris bionic layer 103 The iris biomimetic layer 103 is a key functional layer for achieving biomimetic visual effects. Its design has the following characteristics: Sharing the deformation field with the flexible actuator: The elastic modulus of the iris bionic layer 103 is no more than 3 times the elastic modulus of the flexible actuator, ensuring that the deformation of the actuator is not significantly restricted, and that it can generate continuous deformation following the radial strain.

[0048] It features radial biomimetic textures: the textures include one or more combinations of radial fibers, color spots, crypts, and gradient color bands, simulating the morphological characteristics of a real iris.

[0049] It features a non-uniform radial texture distribution: the texture density or color depth of the inner edge area differs from that of the outer edge area, resulting in a visually differentiated effect of local stretching and enhancing realism.

[0050] The central area forms the pupil: the central area remains dark / black (purely for aesthetic purposes) or transparent (if there is a camera at the bottom for framing), and its diameter changes with the movement of the flexible drive body's inner edge.

[0051] The implementation methods of the iris bionic layer 103 include, but are not limited to: direct printing of flexible inks (screen printing, inkjet printing); flexible film transfer and lamination; multilayer elastic coating; micro-nano structural color (structural color is achieved through periodic micro-nano structures); direct coloring on the surface of a flexible actuator substrate; and laser microtexturing.

[0052] 5. Driving and Control Methods The present invention also provides a control method for the device, which designs a dedicated control strategy for the physical characteristics of the flexible actuator, including: Target pupil diameter determination: Receive emotional state signals and / or ambient light sensor signals from the robot's cognitive system, and determine the target pupil diameter based on a preset mapping relationship or learning model.

[0053] Drive signal generation and hysteresis compensation: The corresponding drive signal is generated based on the drive signal-displacement model of the flexible actuator. To address the inherent hysteresis characteristics of the flexible actuator, an inverse hysteresis model (such as the Prandtl-Ishlinskii inverse model or the Preisach inverse model) is used to perform feedforward compensation on the drive signal.

[0054] Closed-loop feedback correction: The current deformation state and the actual pupil diameter are obtained through external detection devices (such as cameras, optical or displacement detection) and / or flexible actuator self-sensing (such as deformation calculated based on electrical parameters such as capacitance, charge, current, impedance or resistance), and a closed-loop control correction is formed accordingly.

[0055] Time-domain dynamic control: Applying an asymmetric time constant to the driving signal to make the pupil constriction process faster than the pupil dilation process, thus simulating the asymmetric time characteristics of pupil changes in the real human eye.

[0056] 6. Integration with robotic eye systems The device can be mounted on the front or inner surface of a bionic robot eye module and works in conjunction with the following systems: Transparent display layer: If the robot's eyeball uses a transparent display as an auxiliary iris layer, this device can provide a physical sense of pupil depth.

[0057] Camera module: When the central area of ​​the pupil remains transparent, it does not obstruct the viewfinder light path of the underlying camera.

[0058] Eye rotation mechanism: The entire device rotates with the eyeball without affecting eye movement function.

[0059] The specific implementation scheme of the present invention will be described in detail below through multiple embodiments.

[0060] Example 1: Implementation scheme based on dielectric elastomer (DEA) 1. Structure and Materials: Outer frame fixing ring 101: PCB substrate or plexiglass ring structure, which also serves as electrode lead substrate; Circular DEA film: acrylate elastomer (such as VHB series), thinned after pre-stretching; Electrode: Flexible carbon grease electrode (opaque solution) or silver nanowire / PEDOT:PSS transparent conductive layer (transparent solution); Iris bionic layer 103: Elastic ink screen printed on the outer surface of DEA, using radial fiber texture combined with gradient color bands and random color spots.

[0061] 2. Working principle: When a voltage is applied, Maxwell stress causes compression in the thickness direction of the DEA film. Since the elastomer material is approximately incompressible, this leads to in-plane expansion. The outer edge is constrained by the fixing ring and remains stationary, while the deformation is concentrated at the inner edge, resulting in an enlarged inner aperture and a larger pupil visual area. The iris biomimetic layer 103 stretches radially along the DEA surface, and the fiber texture is elongated and thinned, presenting the visual effect of a real pupil when it is dilated.

[0062] 3. Drive circuit: A small boost circuit is used to raise the battery voltage to an adjustable high voltage output. The output voltage is controlled by a DAC, and the MCU calculates the target voltage based on the emotion / light signal and applies hysteresis compensation.

[0063] 4. Performance metrics (examples): Within a reasonable driving voltage range, a radial displacement of approximately 2 mm or more can be achieved, resulting in continuous and noticeable visual changes in the pupil diameter.

[0064] Example 2: Implementation scheme based on liquid crystal elastomer (LCE) 1. Structure and Materials: Outer frame fixing ring 101: Lightweight metal or engineering plastic ring structure; Annular LCE films: Obtaining the desired circumferential or radial strain mode through pre-programmed liquid crystal orientation; Heating method: Flexible heating element embedded in thin film (such as conductive particles to enhance LCE body heating, or additional flexible heating wire). Iris bionic layer 103: elastic film transfer bonding, pre-fabricated radial texture.

[0065] 2. Working principle: Upon heating, the LCE undergoes a liquid crystal phase transition, resulting in anisotropic deformation. According to a pre-programmed orientation pattern, this causes radial displacement of the inner edge, altering the pupil diameter. The iris biomimetic layer 103 changes synchronously with the LCE surface deformation. After cooling and de-energization, it returns to its initial state.

[0066] 3. Features: No high-voltage drive is required; only low-voltage heating current is needed. The deformation state can be monitored by the change in the resistance of the LCE body, which can help to achieve closed-loop control.

[0067] Example 3: Transparent Solution (Compatible with Underlying Camera Viewfinder) The following adjustments were made based on Example 1: The electrodes are made of silver nanowires or PEDOT:PSS transparent conductive layer; The iris bionic layer 103 has iris texture only in the outer annular region, while the central pupil region 104 remains transparent; A miniature camera module is installed at the bottom, which captures the view through the central area of ​​a transparent pupil; This solution can simultaneously achieve visual perception function and bionic pupil appearance.

[0068] Contents not described in detail in this specification are prior art known to those skilled in the art. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A biomimetic pupil-iris linkage device based on a flexible actuator, characterized in that, include: The outer frame fixing ring (101) is a ring-shaped rigid support structure; The annular flexible drive body (102) has its outer edge fixed to the outer frame fixing ring (101) and its inner edge free. Under the action of the drive signal, it generates radial in-plane deformation, so that the central aperture changes continuously to simulate the change of pupil diameter. An iris bionic layer (103) is supported on at least one surface of the flexible actuator or is integrated with the flexible actuator; The device is installed in the eye system of the bionic emotional interaction robot, and the iris bionic layer (103) and the flexible actuator share the same continuous deformation field; Based on the boundary constraint that the outer edge is fixed and the inner edge is free, the flexible actuator naturally forms a radial strain gradient that increases from the outer edge to the inner edge when it deforms in the radial plane. The texture deformation of the iris bionic layer (103) shows a gradient distribution that increases from the outer edge to the inner edge, so that the change in pupil diameter is synchronously coupled with the visual change in iris texture.

2. The biomimetic pupil-iris linkage device based on a flexible actuator according to claim 1, characterized in that: The annular flexible actuator (102) is selected from one of dielectric elastomers, liquid crystal elastomers, thermally responsive elastomers, electrothermal elastomers, magnetically responsive elastomers, pneumatic elastomers, or hydraulic elastomers.

3. The biomimetic pupil-iris linkage device based on a flexible actuator according to claim 2, characterized in that: The dielectric elastomer is an acrylate elastomer or a silicone rubber-based elastomer film, which is thinned after pre-stretching. Flexible conductive electrode layers are provided on the upper and lower surfaces. When a voltage is applied between the electrode layers, Maxwell stress causes compression in the thickness direction, which leads to in-plane expansion based on the material's approximately incompressible properties.

4. The biomimetic pupil-iris linkage device based on a flexible actuator according to claim 2, characterized in that: The liquid crystal elastomer is a thin film with pre-programmed liquid crystal orientation, which undergoes anisotropic deformation under the action of heat, light, or electric field, causing radial displacement of the inner edge.

5. The biomimetic pupil-iris linkage device based on a flexible actuator according to claim 1, characterized in that: The iris bionic layer (103) is formed by one or more of the following methods: flexible ink printing, flexible film transfer, multilayer elastic coating, micro-nano structural color, direct coloring of the substrate surface, or laser micro-texturing, and the elastic modulus of the iris bionic layer (103) is not higher than 3 times the elastic modulus of the flexible actuator.

6. The biomimetic pupil-iris linkage device based on a flexible actuator according to claim 1, characterized in that: The iris bionic layer (103) has a non-uniform radial texture distribution, including one or more of radial fibers, spots and crypts, and the texture density or color depth of the inner edge region is different from that of the outer edge region, so that the local deformation presents a visually differentiated effect.

7. The biomimetic pupil-iris linkage device based on a flexible actuator according to claim 1, characterized in that: The iris bionic layer (103) remains transparent in the central pupil region (104), allowing the bottom optical element to perform optical framing through the central transparent region. The outer frame fixing ring (101) also serves as the electrode lead substrate or structural mounting reference for the flexible actuator.

8. A control method for a biomimetic pupil-iris linkage device based on a flexible actuator as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Receives emotional state signals from the robot's cognitive system and / or ambient light sensor signals, and determines the target pupil diameter according to a preset mapping relationship; The corresponding driving signal is generated based on the driving signal-displacement model of the flexible actuator, and the driving signal is fed forward to compensate by the inverse hysteresis model in order to overcome the inherent hysteresis characteristics of the flexible actuator. The compensated driving signal is applied to the flexible driving body; A dynamic smoothing process with an asymmetric time constant is applied to the driving signal so that the response speed of the pupil constriction process is faster than that of the pupil dilation process, in order to simulate the asymmetric time characteristics of pupil changes in the real human eye.

9. The control method of the biomimetic pupil-iris linkage device based on a flexible actuator according to claim 8, characterized in that: It also includes acquiring the current deformation state through external detection devices and / or self-sensing of the flexible actuator, and performing closed-loop control correction accordingly; the external detection devices are selected from cameras, optical sensors or displacement sensors, and the self-sensing is based on changes in one or more electrical parameters of the flexible actuator, such as capacitance, charge, current, impedance or resistance, to calculate the deformation.

10. The control method of the biomimetic pupil-iris linkage device based on a flexible actuator according to claim 8, characterized in that: The inverse hysteresis model is either the Prandtl-Ishlinskii inverse model or the Preisach inverse model, used to perform nonlinear compensation on the driving signal to ensure the linearity of pupil diameter changes and positioning accuracy.

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