Real-time man-machine interaction bionic hand device

Abstract

The invention provides a real-time man-machine interaction bionic hand device, and relates to the technical field of man-machine interaction, the real-time man-machine interaction bionic hand device comprises a bionic hand and a hand wearable device; the bionic hand comprises a bionic skin layer, an execution sensing layer, a support skeleton layer and a first processing module; the execution sensing layer is used for sensing triggering information of the bionic hand in real time; the first processing module is used for receiving the trigger information and generating a sensing signal based on the trigger information; the trigger information at least comprises stress monitoring information; the hand wearable device comprises a flexible base body layer, a feedback driving layer and a second processing module, the feedback driving layer is embedded in the flexible base body layer, the flexible base body layer is of a negative Poisson's ratio structure, and the feedback driving layer comprises a plurality of shape memory alloy driving units; the second processing module is used for receiving the sensing signal and selectively generating a first driving signal sequence for the feedback driving layer according to the sensing signal. According to the device, real-time tactile and force feedback of the bionic hand is achieved.

Description

Technical Field

[0001] This application relates to the field of human-computer interaction technology, and in particular to a real-time human-computer interaction bionic hand device. Background Technology

[0002] A bionic hand is an intelligent mechanical system that mimics the structure and function of the human hand, and it is widely used in fields such as intelligent prostheses, rehabilitation training, remote control, and human-computer interaction. With the development of flexible electronics, sensing technology, and materials science, the bionic hand has gradually evolved from a traditional mechanical joint structure into an intelligent system with multi-degree-of-freedom motion control and a certain degree of perception.

[0003] However, most existing bionic hands adopt a one-way control mode, that is, the bionic hand is driven to perform actions by the human hand or external signals. They lack real-time tactile and force feedback from the bionic hand and cannot form a closed-loop human-machine collaborative control. Summary of the Invention

[0004] In view of this, this application proposes a real-time human-computer interaction bionic hand device.

[0005] This application provides a real-time human-computer interaction bionic hand device, including: a bionic hand and a wearable hand device; The bionic hand includes a bionic skin layer, an execution sensing layer, a support skeleton layer, and a first processing module; the execution sensing layer is used to sense trigger information of the bionic hand in real time; the bionic skin layer is used to cover the execution sensing layer and the support skeleton layer; the first processing module is used to receive the trigger information and generate a sensing signal based on the trigger information; wherein, the trigger information includes at least stress monitoring information; The wearable hand device includes a flexible substrate layer, a feedback driving layer, and a second processing module. The feedback driving layer is embedded in the flexible substrate layer, which has a negative Poisson's ratio structure. The feedback driving layer includes multiple shape memory alloy driving units. The second processing module is used to receive the sensing signal and selectively generate a first driving signal sequence for the feedback driving layer based on the sensing signal, so as to cause local expansion or contraction of the flexible substrate layer through the phase transition contraction of each shape memory alloy driving unit.

[0006] In one embodiment, the bionic hand further includes an execution driving layer; the wearable hand device further includes a control sensing layer embedded in the flexible substrate layer; The execution drive layer includes at least one finger bone drive unit, each of the finger bone drive units includes a shape memory alloy spring and a traction structure, and the execution drive layer is used to stretch the traction structure by means of the energized phase change contraction characteristics of each of the shape memory alloy springs, so as to drive the flexion and extension of the support skeleton layer. The control perception layer is used to sense the user's hand movement information; the second processing module is also used to receive the hand movement information, generate a synchronization control signal based on the hand movement information and send it to the first processing module; the first processing module is also used to generate a second driving signal sequence for the execution driving layer based on the synchronization control signal.

[0007] In one embodiment, the control sensing layer includes a Bragg grating sensor array that at least covers the finger area of ​​the wearable hand device.

[0008] In one embodiment, the triggering information further includes angle monitoring information. The first processing module is further configured to determine the target angle sequence according to the synchronization control signal, determine the measured angle of each joint according to the angle monitoring information, calculate the error information between the measured angle of each joint and the target angle sequence, and adjust the driving current and heating time of each shape memory alloy spring using a PID algorithm based on the error information.

[0009] In one embodiment, the flexible substrate layer includes a support substrate sublayer, a first elastic sublayer, and a second elastic sublayer stacked sequentially, the feedback driving layer is embedded in the first elastic sublayer, and the control sensing layer is embedded in the second elastic sublayer.

[0010] In one embodiment, the flexible substrate layer includes a finger area and a palm area, wherein the finger area adopts a concave hexagonal re-entrant unit structure and the palm area adopts a concave triangular re-entrant unit structure.

[0011] In one embodiment, the first driving signal is a PWM signal, and the first processing module changes the vibration mode by modulating the frequency and duty cycle of the first driving signal.

[0012] In one embodiment, the feedback driving layer further includes a temperature sensing element for real-time monitoring of the operating temperature of the shape memory alloy driving unit; The second processing module is further configured to receive detection information from the temperature sensing element, and when the temperature of the target shape memory alloy driving unit exceeds a preset temperature threshold, reduce the duty cycle of the target first driving signal to a preset value, wherein the target first driving signal is a signal output to the target shape memory alloy driving unit.

[0013] In one embodiment, the supporting skeleton layer includes metacarpals and at least one phalanx, each of the phalanges being movably connected to the metacarpals; The execution sensing layer includes an angle sensing unit and a Bragg fiber grating sensing unit. The angle sensing unit is disposed at each joint of the phalanx, and the Bragg fiber grating sensing unit is disposed inside the bionic skin layer. The measuring points of the Bragg fiber grating sensing unit cover the metacarpals and each of the phalanges.

[0014] In one embodiment, each measuring point is provided with a set of Bragg fiber gratings. Each set of Bragg fiber gratings includes two Bragg fiber gratings corresponding to different center wavelengths. One Bragg fiber grating is directly disposed in the bionic skin layer to sense the superposition information of strain and temperature, and the other Bragg fiber grating is placed in a strain isolation yarn tube to achieve strain isolation.

[0015] The real-time human-computer interaction bionic hand device proposed in this application has the following advantages over related technologies: 1. The real-time human-computer interaction bionic hand device of this application includes a bionic hand and a wearable hand device. The execution sensing layer of the bionic hand can capture trigger information, including stress monitoring information, in real time, and convert it into accurate sensing signals through the first processing module, providing reliable data support for tactile feedback. The wearable hand device adopts a flexible substrate layer with a negative Poisson's ratio structure. Its lateral expansion characteristic under force can adaptively conform to the curvature of the hand, ensuring wearing comfort and contact stability. Multiple shape memory alloy driving units embedded in the flexible substrate layer, under the control of the first driving signal sequence generated after the second processing module receives the sensing signals, can achieve local expansion or contraction of the flexible substrate layer through phase change contraction, thereby generating targeted tactile feedback such as pressure and stiffness changes on the skin surface. Moreover, the independent control of multiple driving units supports multi-point, programmable feedback modes. By combining the real-time perception of the bionic hand with the precise feedback of wearable devices, this device achieves a closed-loop interaction from trigger perception to tactile output. This not only significantly improves the naturalness and response accuracy of human-computer interaction, but also, thanks to the combination of a negative Poisson's ratio structure and a shape memory alloy drive unit, balances wearing comfort and richness of feedback modes, making it suitable for various scenarios that require precise tactile interaction.

[0016] 2. The control and sensing layer of the wearable hand device is embedded in a negative Poisson's ratio flexible substrate layer. Without compromising wearing comfort, it accurately captures the user's hand movements, providing real-time and reliable user input. The second processing module receives this hand movement information, generates a synchronous control signal, and transmits it to the first processing module. This achieves efficient transmission and synchronous parsing of user movement signals between devices, ensuring immediate interactive response. The first processing module generates a second drive signal sequence based on the synchronous control signal, driving the bionic hand's execution drive layer. Utilizing the shape memory alloy spring's phase-change contraction characteristic, it stretches the traction structure, precisely driving the support skeleton layer to complete flexion and extension movements. This allows the bionic hand to follow the user's hand flexion and extension in real time, enabling intuitive and precise user control of the bionic hand. Combined with the previous tactile feedback mechanism, this forms a complete two-way interactive closed loop. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a block diagram of the interaction structure of a real-time human-computer interaction bionic hand device in one embodiment of this application; Figure 2 This is a schematic diagram of the structure of a real-time human-computer interaction bionic hand device in one embodiment of this application; Figure 3 This is a schematic diagram of the sensing and monitoring structure of a bionic hand in one embodiment of this application; Figure 4 This is a schematic diagram of the skeletal structure of a bionic hand in one embodiment of this application; Figure 5 This is a schematic diagram of the structure of a wearable hand device in one embodiment of this application; Figure 6 This is a block diagram of the interaction structure of a real-time human-computer interaction bionic hand device in another embodiment of this application; Figure 7 This is a schematic block diagram illustrating the interaction principle of a real-time human-computer interaction bionic hand device in one embodiment of this application; Figure 8 This is a schematic diagram of the driving structure of the bionic hand in one embodiment of this application; Figure 9 This is a schematic diagram of the structure of the flexible substrate layer in one embodiment of this application; Figure 10 This is a schematic diagram of the kinematic coordinate system of a finger bone in one embodiment of this application; Figure 11This is a schematic diagram of the movement space of the finger bone in one embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: 1-Bionic hand, 11-Bionic skin layer, 12-Execution sensing layer, 121-Angle sensing unit, 122-Bragg fiber grating sensing unit, 13-Support skeleton layer, 131-Metacarpal bone, 132-Phalangeal bone, 1321-Proximal phalanx, 1322-Middle phalanx, 1323-Distal phalanx, 14-First processing module, 15-Execution driving layer, 151-Phalangeal bone driving unit, 1511-Traction structure, 1512-Shape memory alloy spring, 2-Wearable hand device, 21-Flexible substrate layer, 211-Support substrate sublayer, 212-First elastic sublayer, 213-Second elastic sublayer, 22-Feedback driving layer, 23-Second processing module, 24-Control sensing layer. Detailed Implementation

[0020] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0023] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] In some embodiments, such as Figure 1 and Figure 2 As shown, this application provides a real-time human-computer interaction bionic hand 1 device, including: a bionic hand 1 and a wearable hand device 2.

[0025] like Figure 3 and Figure 4 As shown, the bionic hand 1 includes a bionic skin layer 11, an execution sensing layer 12, a support skeleton layer 13, and a first processing module 14; the execution sensing layer 12 is used to sense the trigger information of the bionic hand 1 in real time; the bionic skin layer 11 is used to cover the execution sensing layer 12 and the support skeleton layer 13; the first processing module 14 is used to receive the trigger information and generate a sensing signal based on the trigger information; wherein, the trigger information includes at least stress monitoring information.

[0026] The supporting skeleton layer 13 can be made of carbon fiber reinforced epoxy resin or glass fiber reinforced resin, and is fabricated as a connecting frame between the metacarpals 131 and phalanges 132 through 3D printing or molding processes, providing high-strength and lightweight support. The actuation sensing layer 12 can be embedded within the bionic skin layer 11. The actuation sensing layer 12 can include a fiber optic grating array, which can be arranged along the joint movement direction, to monitor the stress information experienced by the bionic hand 1. The bionic skin layer 11 is a silicone or PDMS material covering the outermost layer of the bionic hand 1, serving a protective and cushioning function.

[0027] like Figure 5 As shown, the wearable hand device 2 includes a flexible substrate layer 21, a feedback driving layer 22, and a second processing module 23. The feedback driving layer 22 is embedded in the flexible substrate layer 21, which has a negative Poisson's ratio structure. The feedback driving layer 22 includes multiple shape memory alloy (SMA) driving units. The second processing module 23 is used to receive sensing signals and selectively generate a first driving signal sequence for the feedback driving layer 22 based on the sensing signals, so as to cause local expansion or contraction of the flexible substrate layer 21 through the phase change contraction of each shape memory alloy driving unit.

[0028] The first driving signal can be a PWM signal. The shape memory alloy driving unit can be a NiTi-based shape memory alloy wire or a spring, which generates contractile force through a martensitic-austenitic phase transformation caused by electrical heating, thus achieving structural bending or stretching. The flexible substrate layer 21 has a negative Poisson's ratio structure, so the corresponding area of ​​the flexible substrate layer 21 can expand laterally when the shape memory alloy driving unit bends or stretches, thereby adaptively conforming to different hand shapes and hand curves. This structural design of the flexible substrate layer 21 not only improves wearing comfort but also amplifies the tiny displacements generated by the shape memory alloy driving, making tactile feedback more obvious and the response faster.

[0029] It is understandable that an FBG grating array is arranged under the bionic skin layer 11 to detect contact stress information, and then the strain... ε With wavelength drift Δλ B The relationship is:

[0030] Through structural equivalent stiffness K s Establish contact force model For example, if Δλ B =27pm, then calculate F c =2.8N, the first processing module 14 can be based on F c Calculate the average contact pressure p The data is then transmitted wirelessly to the second processing module 23. For example, the finger area structure in the wearable hand device 2 is a concave hexagonal re-entrant unit structure. Therefore, for the structural unit of the finger area, let the length of the inclined rib be... rib thickness is The concave angle is The unit height is Then, ignoring rib bending deformation and only considering rib axial expansion and contraction, the element height can be approximated as:

[0031]

[0032] When the shape memory alloy drive unit arranged along the inclined ribs generates axial contraction strain At that time, it causes a decrease in rib length. From geometric relationships, the change in unit height can be obtained as follows:

[0033] in, SMA-driven strain. Therefore, the normal displacement (the amount of pressure indented into the skin) is:

[0034]

[0035] in, For normal displacement, This represents the change in element height. That is, there is a linear relationship between the normal displacement and the SMA contraction strain. Negative Poisson's ratio magnification factor Considering that the equivalent elastic modulus of the concave hexagonal honeycomb under normal loading is... E eq Thickness is H c, then the element normal stiffness , For the equivalent elastic modulus, Let be the projected area of ​​the unit. For ... N The contact region consisting of c elements has an overall normal stiffness of . The corresponding average contact pressure p It can be written as:

[0036]

[0037] in, Let be the area coverage coefficient of the concave hexagonal element within the contact region. A c Given the skin contact area, it can be seen that, under given SMA-driven strain conditions, the concave hexagonal negative Poisson's ratio structure significantly improves the tactile pressure response of the skin surface through a geometric amplification effect, so that even a small SMA contraction can generate perceptible normal pressure stimulation.

[0038] When the sensory layer 12 of the bionic hand 1 senses external stress or temperature changes, the feedback sensory signal is transmitted back to the second processing module 23 through the first processing module 14. The corresponding shape memory alloy driving unit is activated, generating perceptible tactile stimulation locally, realizing real-time restoration of force feedback. For example, the shape memory alloy driving layer can be a heat-treated pre-formed NiTi shape memory alloy wire with a negative Poisson's ratio structure, so that the shape memory alloy wire can be embedded inside the flexible substrate layer 21. The shape memory alloy wire can be continuously arranged along the structural border of the flexible substrate layer 21 to form a driving network. After being energized, the shape memory alloy wire undergoes a martensitic-austenitic phase transformation and recovers its preset shape. The shape memory alloy wire transmits driving force through adhesion to the flexible substrate layer 21, causing the flexible layer to contract locally or bend overall, generating skin-perceptible tactile stimulation.

[0039] In the application, the second processing module 23 can selectively activate the shape memory alloy driving unit inside the wearable device based on the intensity of the sensed signal. When the intensity of the sensed signal is less than a certain value, the first driving signal can be left unsent to the shape memory alloy driving unit. When the intensity of the sensed signal is greater than or equal to a certain value, the first driving signal is sent to the corresponding shape memory alloy driving unit, causing the shape memory alloy to undergo controlled heating and phase change contraction, resulting in local expansion or contraction of the flexible negative Poisson's ratio structure. This generates perceptible normal pressure, slight vibration, or temperature stimulation on the wearer's skin, achieving realistic tactile feedback. The feedback intensity corresponding to the sensed signal can be adaptively set according to the user's sensitivity, and a built-in temperature limit can be set. When the temperature of the shape memory alloy exceeds a certain value (e.g., 50°C) or the temperature rise of the skin surface exceeds a certain value (e.g., 33°C), the PWM duty cycle is automatically reduced using preset adjustment parameters to ensure safe use.

[0040] The aforementioned real-time human-computer interaction bionic hand device includes a bionic hand 1 and a wearable hand device 2. The execution sensing layer 12 of the bionic hand 1 can capture trigger information, including stress monitoring information, in real time, which is then converted into precise sensing signals by the first processing module 14, providing reliable data support for tactile feedback. The wearable hand device 2 adopts a flexible substrate layer 21 with a negative Poisson's ratio structure. Its lateral expansion characteristic under force can adaptively conform to the curved surface of the hand, ensuring wearing comfort and contact stability. Multiple shape memory alloy driving units embedded in the flexible substrate layer 21, under the control of the first driving signal sequence generated after the second processing module 23 receives the sensing signals, can achieve local expansion or contraction of the flexible substrate layer 21 through phase change contraction, thereby generating targeted tactile feedback such as pressure and stiffness changes on the skin surface. The independent control of multiple driving units supports multi-point, programmable feedback modes. By combining the real-time perception of the bionic hand 1 with the precise feedback of the wearable device, the device achieves a closed-loop interaction from trigger perception to tactile output. This not only significantly improves the naturalness and response accuracy of human-computer interaction, but also, thanks to the combination of a negative Poisson's ratio structure and a shape memory alloy drive unit, balances wearing comfort and richness of feedback modes, making it suitable for various scenarios that require precise tactile interaction.

[0041] In some embodiments, such as Figure 6 and Figure 7 As shown, the bionic hand 1 also includes an execution drive layer 15; the wearable hand device 2 also includes a control sensing layer 24, which is embedded in the flexible substrate layer 21.

[0042] like Figure 8As shown, the execution drive layer 15 includes at least one finger bone drive unit 151. Each finger bone drive unit 151 includes a shape memory alloy spring 1512 and a traction structure 1511. The execution drive layer 15 is used to stretch the traction structure 1511 by means of the energized phase change contraction characteristics of each shape memory alloy spring 1512, so as to drive the flexion and extension of the support skeleton layer 13. The traction structure 1511 can be a drive wire.

[0043] In applications, pre-formed NiTi shape memory alloy springs 1512 can be embedded at the joints of each finger and the metacarpophalangeal joint. One end of each spring 1512 is fixed to the finger bone frame, and the other end is connected to a traction structure 1511. Upon heating, the spring 1512 transforms from martensitic to austenitic phase and contracts, generating a linear contractile force. This force, through a lever effect, causes the joint to bend, achieving movements similar to human muscles. The shape memory alloy drive network consists of multiple independent channels, each of which can be independently adjusted via a corresponding drive signal, enabling multi-finger coordination.

[0044] The control sensing layer 24 is used to sense the user's hand gesture information; the second processing module 23 is also used to receive the hand gesture information, generate a synchronization control signal based on the hand gesture information, and send it to the first processing module 14; the first processing module 14 is also used to generate a second drive signal sequence for the execution drive layer 15 based on the synchronization control signal. The second drive signal can be a PWM signal.

[0045] The control sensing layer 24 may include a Bragg grating sensor array, which at least covers the finger area of ​​the wearable hand device 2. The Bragg grating sensor array may use a single-mode silica fiber Bragg grating as the sensing element. The fiber core material may be high-purity silica. A periodic refractive index modulation structure is formed in the fiber core through ultraviolet exposure, which can reflect light signals of a specific wavelength. The center wavelength of the reflection shifts with strain or temperature changes, enabling real-time measurement of stress, temperature, and bending angle.

[0046] It is understood that the wearable hand device 2 worn by the user detects the user's hand movements in real time through the control sensing layer 24. For example, it can detect hand movements by detecting the bending angle, flexion and extension speed, and relative displacement of the finger joints. If the control sensing layer 24 can include a Bragg grating sensor array, the local strain ε and temperature T change of the corresponding node can be determined by the spectral reflection wavelength drift Δλ of each fiber grating node. Then, the second processing module 23 performs multi-point data fusion and coordinate transformation (angle-pose mapping) based on the detection signal, and then sends a synchronization control signal to the first processing module 14 via the wireless communication module in the form of a PWM pulse width modulation signal. After receiving the synchronization control signal, the first processing module 14 generates a second driving signal sequence for the execution driving layer 15 according to the synchronization control signal. The corresponding finger bone driving unit 151 is activated, and the shape memory alloy spring 1512 transforms from martensitic phase to austenitic phase and generates contractile force, realizing the flexion and extension movements of the finger joints.

[0047] The forward drive chain of this application is used to achieve real-time control of the bionic hand 1 by the wearer's hand movements. The FBG is embedded in the flexible substrate layer 21 along the principal strain direction of bending on the back of the fingers and the palm. It obtains information on the changes in strain, bending angle, and flexion-extension speed of the finger joints in real time through reflected wavelength drift. satisfy:

[0048] in, The center reflection wavelength of the fiber optic grating. ε For axial strain, For temperature changes, p e The effective photoelastic coefficient of the optical fiber. ξ This is the thermo-optic coefficient. This application can eliminate temperature interference using a compensation grating or differential method, yielding:

[0049]

[0050] in, k ε The strain sensitivity coefficient represents the actual bending angle of the finger joint. θ With strain ε The relationship is:

[0051] in, h This represents the height of the optical fiber relative to the neutral layer. L To reconstruct the hand posture in real time, data is fused from multiple fiber optic nodes to represent the arc length corresponding to the finger joint flexion.

[0052] in, The target joint angle vector for the finger joint. Attitude mapping matrix, This represents the wavelength drift vector of the optical fiber. The first processing module 14 or the second processing module 23 may include a spectral demodulator, a microcontroller, and a wireless communication module. The functions of the processing modules may include: multi-point grating data fusion, Kalman filtering noise filtering, attitude solving and constraint processing, and target angle output and PWM control command generation. The bionic hand 1 internally uses NiTi shape memory alloy (SMA) as the driving element. Through electrical heating, a martensitic-austenitic phase transformation is induced to generate contractile force, realizing the flexion and extension movements of the phalanx 132 joint. The dynamic response model is as follows:

[0053]

[0054] in, SMA-driven strain, K D This represents the gain coefficient of the SMA drive strain and the PWM duty cycle. D For PWM duty cycle, The heating time constant for the SMA. Output rotation angle of joint 1 in the bionic hand. for:

[0055]

[0056] in, It is the mechanical amplification factor, which enables a controllable mapping from the duty cycle D to the joint angle output.

[0057] In this embodiment, the control sensing layer 24 of the wearable hand device 2 is embedded in the negative Poisson's ratio flexible substrate layer 21. Without affecting wearing comfort, it can accurately capture the user's hand movement information, providing the device with real-time and reliable user intention input. After receiving the hand movement information, the second processing module 23 generates a synchronous control signal and transmits it to the first processing module 14, realizing efficient transmission and synchronous parsing of user movement signals between devices, ensuring the immediacy of interactive response. The first processing module 14 generates a second driving signal sequence based on the synchronous control signal, driving the execution driving layer 15 of the bionic hand 1. Utilizing the characteristic of the shape memory alloy spring 1512 to stretch the traction structure through phase change contraction when energized, it can accurately drive the support skeleton layer 13 to complete flexion and extension movements, enabling the bionic hand 1 to follow the user's hand flexion and extension in real time. This achieves intuitive and precise control of the bionic hand 1 by the user, forming a complete two-way interactive closed loop when combined with the previous tactile feedback mechanism.

[0058] In some embodiments, the trigger information further includes angle monitoring information. The first processing module 14 is also used to determine the target angle sequence according to the synchronization control signal, determine the measured angle of each joint according to the angle monitoring information, calculate the error information between the measured angle of each joint and the target angle sequence, and adjust the driving current and heating time of each shape memory alloy spring using a PID algorithm based on the error information.

[0059] It is understandable that the joint rotation error between the measured angles of each joint and the target angle sequence... for:

[0060] in, For the target joint angle, To determine the actual output angle of the bionic hand 1, the error of the joint angle is controlled using PID control:

[0061] in, K p , K i and K d These are the proportional system coefficient, integral coefficient, and derivative coefficient, respectively. The PWM duty cycle of the MPU output is limited to between 0 and 1.

[0062]

[0063] in, For PWM duty cycle, k u This is the proportionality coefficient. The synchronization accuracy in this embodiment is...

[0064]

[0065] Typical closed-loop time constant The value ranges from 0.05 to 0.08, ultimately achieving a motion delay of <90ms and a synchronization angle error of ≤2°, ensuring that the motion of the bionic hand 1 is highly consistent with that of the human hand.

[0066] For example, the wearable FBG detected Δλ B =18pm, the bending angle is calculated. θ ref =32°, the second processing module 23 sends via Bluetooth. θ ref The instruction is sent to the first processing module 14 of the bionic hand 1. After receiving the signal, the first processing module 14 controls the execution drive layer 15 to start with a PWM duty cycle of 0.42 and outputs... θ out=30.5°, the internal FBG of the bionic hand 1 obtains the real-time angle and performs closed-loop correction, and finally reduces the error synchronously.

[0067] In some embodiments, such as Figure 9 As shown, the flexible substrate layer 21 includes a support substrate sublayer 211, a first elastic sublayer 212 and a second elastic sublayer 213 stacked in sequence, a feedback driving layer 22 embedded in the first elastic sublayer 212 and a control sensing layer 24 embedded in the second elastic sublayer 213.

[0068] The supporting matrix sublayer 211 can be carbon fiber reinforced epoxy resin or glass fiber reinforced resin, providing structural strength and shape retention, ensuring overall stability and lightweight. The first elastic sublayer 212 and the second elastic sublayer 213 can be polydimethylsiloxane or thermoplastic polyurethane, serving as embedding carriers for the shape memory alloy and fiber optic grating. They are fixed in the corresponding elastic sublayers by mold curing, achieving the integration of actuation and sensing while providing flexibility and cushioning performance.

[0069] In this embodiment, the supporting substrate sublayer 211 provides stable structural support for the flexible substrate layer 21, ensuring that the device is not easily deformed during wear and use, and providing a reliable mounting carrier for the feedback drive layer 22 and the control sensing layer 24. The first elastic sublayer 212 and the second elastic sublayer 213 continue the negative Poisson's ratio structural characteristics of the flexible substrate layer 21. With good elasticity and deformation capability, they not only ensure the comfort of the device conforming to the curved surface of the hand, but also achieve adaptive fit by cooperating with lateral expansion when subjected to force. By embedding the feedback drive layer 22 and the control sensing layer 24 into the independent first elastic sublayer 212 and second elastic sublayer 213 respectively, physical isolation and functional partitioning of the two can be achieved. This effectively avoids the phase change contraction / expansion of the shape memory alloy drive unit during the drive process from interfering with the motion capture of the control sensing layer 24, and also prevents the sensing elements of the control sensing layer 24 from affecting the local deformation transmission of the feedback drive layer 22, ensuring the accuracy of tactile feedback and the sensitivity of hand motion perception.

[0070] In some embodiments, such as Figure 5 As shown, the flexible substrate layer 21 includes a finger area and a palm area. The finger area adopts a concave hexagonal re-entrant unit structure, and the palm area adopts a concave triangular re-entrant unit structure.

[0071] It is understandable that the negative Poisson's ratio structure layer is divided into a finger area and a palm area. The finger area adopts a concave hexagonal re-entry unit structure, and the palm area adopts a concave triangular re-entry unit structure. Through the partitioning and combination of hexagonal and triangular structures, a functional gradient design with a soft upper part and a stable lower part can be achieved, taking into account both flexible fit and mechanical support.

[0072] It should be noted that the finger area is the main sensing and interaction part of the wearable hand device 2 in this application, and its structural design must simultaneously meet the requirements of high flexibility, bendability, tactile amplification capability, and multi-point actuation response characteristics. To accommodate different usage scenarios and mechanical characteristics, the negative Poisson's ratio structure of the finger area can adopt the following three alternative or combined schemes: improved hexagonal honeycomb structure, concave hexagonal re-entrant unit structure, and concave triangular re-entrant unit structure. All three topological units can be prepared in a polydimethylsiloxane flexible matrix by molding, and heat-treated NiTi shape memory alloy wires are embedded inside the structure to achieve independent or collaborative actuation. By adjusting the unit shape parameters (corners, thickness, tilt angle, etc.) and arrangement, continuous control from high flexibility to high support can be achieved.

[0073] In some embodiments, the first driving signal is a PWM signal, and the first processing module 14 changes the vibration mode by modulating the frequency and duty cycle of the first driving signal.

[0074] In the application, three feedback modes can be selected according to the tactile interaction requirements: static pressure mode, dynamic vibration mode, and variable stiffness mode. The static pressure mode uses a constant or low-frequency PWM signal with a high duty cycle to continuously heat the palm or finger base area, keeping the SMA lines stably contracted, simulating continuous force feedback such as gripping and pressing. The dynamic vibration mode uses a high-frequency, low-duty-cycle PWM pulse to intermittently heat the fingertips or finger pads, generating rapid and perceptible micro-vibrations or tapping sensations, used for cue feedback or texture interaction. The variable stiffness mode applies a medium-intensity, long-duration PWM current to the palm area and some finger areas, maintaining the SMA lines in a partially austenitic state, thereby increasing the equivalent stiffness of the local structure, used for grip strength assistance or rehabilitation support. The tactile intensity of each area is determined by the mapping relationship of "force level—current—duty cycle." The second processing module 23 selects the activation area and force level based on the perceived information, realizing multimodal tactile output including single-point stimulation, zone combination stimulation, and sequential sliding stimulation.

[0075] In some embodiments, the feedback driving layer 22 further includes a temperature sensing element for real-time monitoring of the operating temperature of the shape memory alloy driving unit.

[0076] The second processing module 23 is also used to receive detection information from the temperature sensing element, and when it is determined from the detection information that the temperature of the target shape memory alloy driving unit exceeds a preset temperature threshold, the duty cycle of the target first driving signal is reduced to a preset value, wherein the target first driving signal is a signal output to the target shape memory alloy driving unit.

[0077] It is understandable that, since the phase transformation characteristics of shape memory alloys are closely related to their operating temperature, excessively high temperatures can not only lead to a decline in key properties such as elastic modulus and restoring force, but may also cause material fatigue, permanent deformation, or even burnout, thereby affecting the reliability and service life of the feedback drive layer 22. The second processing module 23, by monitoring temperature data in real time, determines that the operating temperature of the shape memory alloy exceeds a set threshold. By promptly reducing the duty cycle of the target first drive signal, it effectively avoids irreversible damage to the shape memory alloy caused by high temperatures, extending its service life, and also prevents problems such as decreased drive accuracy and abnormal knuckle movement caused by temperature runaway.

[0078] It should be noted that the drive layer 15 can also be equipped with a temperature sensing element to monitor the operating temperature of the shape memory alloy in real time. The first processing module 14 is also used to reduce the amplitude of the drive signal or stop outputting the drive signal when the operating temperature of the shape memory alloy spring exceeds a set threshold. In application, thermal grease can also be filled into the shape memory alloy mounting cavity and heat dissipation holes can be opened to improve heat dissipation efficiency.

[0079] In some embodiments, such as Figure 4 As shown, the supporting skeleton layer 13 includes metacarpals 131 and at least one phalanx 132, with each phalanx 132 movably connected to the metacarpal 131. The shape and size of the metacarpals 131 and phalanx 132 can be replicated according to the parameters of real human hand joints to ensure biomechanical simulation. The phalanges can be connected by micro-hinges as joints to form a mechanical skeleton with multiple degrees of freedom.

[0080] The execution sensing layer 12 includes an angle sensing unit 121 and a Bragg fiber grating sensing unit 122. The angle sensing unit 121 is disposed at each joint of the phalanges 132, and the Bragg fiber grating sensing unit 122 is disposed inside the bionic skin layer 11. The measuring points of the Bragg fiber grating sensing unit 122 cover the metacarpals 131 and each phalanx 132.

[0081] In applications, the angle sensor can be a Hall effect angle sensor, a photoelectric encoder, or a MEMS attitude sensor. The skeleton can have pre-reserved drive channels and sensing slots for embedding the shape memory alloy spring 1512, the angle sensing unit 121, and the Bragg fiber grating sensing unit 122.

[0082] In some embodiments, each measuring point is provided with a set of Bragg fiber gratings. Each set of Bragg fiber gratings includes two Bragg fiber gratings corresponding to different center wavelengths. One Bragg fiber grating is directly disposed in the bionic skin layer 11 to sense the superposition information of strain and temperature. The other Bragg fiber grating is placed in a strain isolation yarn tube to achieve strain isolation, thereby measuring temperature.

[0083] It is understandable that by arranging a set of Bragg fiber gratings at each measuring point, local strain and temperature changes at each measuring point can be sensed based on the grating monitoring signals. The fiber grating can be made of single-mode PI-coated fiber, with a periodic grating structure etched in the fiber core to reflect light signals of specific wavelengths. Single-mode PI-coated fiber has high flexibility and high temperature resistance, capable of withstanding temperature and stress changes during silicone curing. After the incident light is transmitted through the fiber into the grating region, part of the light is reflected. The reflected wavelength drifts with changes in external strain or temperature, and the amount of change in the reflected wavelength is proportional to the stress and temperature changes at that location. The central reflected wavelength of the Bragg fiber grating is:

[0084]

[0085] In the above formula, λ B For the reflected center wavelength, n eff The effective refractive index of the fiber core, This represents the spatial period of the grating. When the optical fiber is subjected to external stress or temperature changes... n eff and All of these will change, causing a shift in the reflected wavelength. The amount of wavelength change can be expressed as:

[0086]

[0087] The axial strain experienced by the optical fiber. The change in temperature P e The effective elastic-optical coefficient of the optical fiber. α The thermal expansion coefficient of optical fiber ξ The thermo-optic coefficient of the optical fiber. To achieve simultaneous monitoring and separation of temperature and stress, this embodiment employs a dual-grating decoupling design: two FBGs with different center wavelengths are connected in series on the same optical fiber. One is directly bonded to the silicone skin to sense the superposition effect of strain and temperature; the other can be placed in a PTFE capillary to achieve strain isolation, responding only to temperature changes. The wavelength changes of the two are as follows:

[0088]

[0089] The reflection wavelength shift of the two gratings is measured in real time using a spectral demodulation system. and This allows us to determine the stress and temperature changes at that location.

[0090] In the application, during the fabrication of the bionic skin layer 11, fiber optic slots and lead-out holes can be pre-reserved in the corresponding mold. The optical fibers are arranged in shallow grooves etched on the surface of the mold core and fixed with silicone adhesive. Before casting, a thin silicone layer is laid to form the substrate, and then the FBG optical fiber is placed. A second casting is then performed to cover and form the overall skin. The optical fiber is positioned 0.3–0.5 mm from the skin surface at the fingertip to ensure strain transmission sensitivity. Part of the temperature reference grating is placed inside a PTFE capillary to achieve separation and decoupling of strain and temperature. The lead-out ends of the optical fibers are concentrated at the wrist and connected to the external demodulation module through a flexible protective sleeve. A stress relief cavity is provided at the wrist to prevent fiber bending damage.

[0091] In some embodiments, such as Figure 3 As shown, there are five finger bones 132, and the Bragg fiber grating sensing unit 122 includes multiple measuring optical fibers.

[0092] Each phalanx 132 is equipped with a corresponding measuring optical fiber, and the metacarpal bone 131 area is equipped with four measuring optical fibers. Each optical fiber in the phalanx 132 area is connected in series with three sets of Bragg fiber gratings, and each optical fiber in the palm area is connected in series with three sets of Bragg fiber gratings.

[0093] It is understandable that the number of finger bones 132 is set to five, which perfectly matches the structure of the five fingers of the human hand, and can reproduce the grasping posture and range of motion of the human hand to the greatest extent, providing a structural basis for diverse grasping actions. The Bragg fiber grating sensing unit 122 is equipped with multiple measuring optical fibers. The measuring optical fibers corresponding to the five finger bones 132 can independently collect the stress signals of each finger, avoiding signal interference between different finger bones 132 and ensuring the accuracy of single finger stress monitoring. The four measuring optical fibers arranged in the metacarpal bone 131 area can fully cover key contact areas such as the palm and palmar edge, making up for the deficiency of incomplete coverage by a single optical fiber.

[0094] Meanwhile, the design of connecting three sets of Bragg fiber gratings in each fiber in the phalanx 132 region and three sets of Bragg fiber gratings in each fiber in the palm region significantly increases the measurement point density. This allows independent and continuous stress monitoring data to be obtained from the proximal, middle, and distal ends of the phalanx 132 and different sections of the metacarpal 131. This not only enables accurate capture of stress changes in each movement segment of the phalanx 132 and each contact area of ​​the metacarpal 131, but also effectively avoids the one-sidedness and error of single-point monitoring through the collaborative sensing of multiple sets of gratings. This high-density, zoned sensor arrangement allows the Bragg fiber grating sensor unit 122 to output more comprehensive and detailed grating monitoring signals. Combined with the angle monitoring signals of the angle sensor unit 121, it provides multi-dimensional, comprehensive sensing data support for the first processing module 14. This enables the first processing module 14 to accurately determine the bending information of each finger bone 132 and the stress distribution in different areas. Consequently, it can adjust the driving signals of the execution driving layer 15 accordingly, ensuring that the bionic hand 1 can correct its movement trajectory based on the bending feedback of the finger bones 132 and accurately control the gripping force based on the zoned stress feedback during the grasping process. This significantly improves the adaptability to objects of different shapes and sizes and the precision of gripping control, making the movements more in line with the natural movement patterns of the human hand and the gripping more stable and reliable.

[0095] In some embodiments, such as Figure 4 and Figure 10 As shown, the phalanx 132 includes a proximal phalanx 1321, a middle phalanx 1322, and a distal phalanx 1323. The middle phalanx 1322 and the distal phalanx 1323 are connected by a distal interphalangeal joint. The proximal phalanx 1321 and the middle phalanx 1322 are connected by a proximal interphalangeal joint. The proximal phalanx 1321 is connected to the metacarpal bone 131 by a metacarpophalangeal joint.

[0096] Based on the structural design and the physiological range of human phalanges 132, the constraints are set as follows: the bending angle of the metacarpophalangeal joint is 0°-90°, the swing angle of the metacarpophalangeal joint is -20°-20°, the bending angle of the proximal interphalangeal joint is 0°-100°, and the bending angle of the distal interphalangeal joint is 0°-80°.

[0097] In applications, the metacarpophalangeal joint has two degrees of freedom, with a spatial offset between its bending axis and its pivoting axis. l 1. The flexion angle and swing angle of the metacarpophalangeal joint are respectively θ 1 and α 1. The flexion angles of the proximal and distal interphalangeal joints are respectively θ 2 and θ 3. The lengths of the proximal phalanx 1321, the middle phalanx 1322, and the distal phalanx 1323 are respectively l 2. l 3. l4. Based on the Denavit-Hartenberg method, the position of the fingertip in the base coordinate system can be obtained through four homogeneous transformation matrices:

[0098]

[0099] in:

[0100] After multiplication, we obtain the homogeneous transformation matrix of the fingertips relative to the base of the palm:

[0101] Where R is the attitude matrix. This represents the fingertip position vector. After setting constraints based on the structural design and the physiological range of the human phalanx 132, the motion space of the phalanx 132 is obtained as follows: Figure 11 As shown, the above limitations ensure that the bionic hand 1 conforms to the bone parameters of a real human hand, thus guaranteeing bionic accuracy.

[0102] In some embodiments, each finger bone driving unit 151 includes two shape memory alloy springs 1512, which are respectively arranged on the back and the pad of the finger bone 132. The shape memory alloy spring 1512 at the pad is used to drive the finger bone 132 to bend towards the palm, and the shape memory alloy spring 1512 at the back is used to drive the finger bone 132 to extend.

[0103] It can be understood that two shape memory alloy springs 1512 are respectively arranged on the back and the pad of the finger bone 132. The shape memory alloy spring 1512 at the pad is used to drive the finger bone 132 to bend towards the palm, and the shape memory alloy spring 1512 at the back is used to drive the finger bone 132 to extend. The flexion and extension movements can be completed by the pair of shape memory alloy springs 1512 working together to achieve an antagonistic drive arrangement at the back and pad positions, thereby obtaining a flexibility similar to that of human finger bones 132.

[0104] Those skilled in the art will understand that the features described in the various embodiments of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application. Therefore, the scope of this application should not be limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A real-time human-robot interaction bionic hand device, characterized by, The application relates to a bionic hand and a hand wearable device. The bionic hand comprises a bionic skin layer, an execution sensing layer, a support skeleton layer and a first processing module. The execution sensing layer is used for sensing trigger information of the bionic hand in real time. The bionic skin layer is used for covering the execution sensing layer and the support skeleton layer. The first processing module is used for receiving the trigger information and generating a sensing signal based on the trigger information; wherein the trigger information at least comprises stress monitoring information. The hand wearable device comprises a flexible matrix layer, a feedback driving layer and a second processing module, the feedback driving layer is embedded in the flexible matrix layer, the flexible matrix layer is a negative Poisson ratio structure, the feedback driving layer comprises a plurality of shape memory alloy driving units; the second processing module is used for receiving the sensing signal and selectively generating a first driving signal sequence for the feedback driving layer according to the sensing signal, so as to cause the flexible matrix layer to locally expand or shrink through phase change contraction of each shape memory alloy driving unit. The bionic hand further comprises an execution driving layer; the hand wearable device further comprises a control sensing layer, and the control sensing layer is embedded in the flexible matrix layer.

2. The real-time human-interactive bionic hand device of claim 1, wherein, The execution driving layer comprises at least one phalanx driving unit, each phalanx driving unit comprises a shape memory alloy spring and a traction structure, and the execution driving layer is used for stretching the traction structure through the electrically conductive phase change contraction characteristics of each shape memory alloy spring, so as to drive the support skeleton layer to bend and stretch. The control sensing layer is used for sensing hand action information of a user; the second processing module is further used for receiving the hand action information, generating a synchronous control signal according to the hand action information and sending the synchronous control signal to the first processing module; and the first processing module is further used for generating a second driving signal sequence for the execution driving layer according to the synchronous control signal. The control sensing layer comprises a Bragg grating sensor array, and the Bragg grating sensor array at least covers a finger area of the hand wearable device.

3. The real-time human-interactive bionic hand apparatus of claim 2, wherein, The trigger information further comprises angle monitoring information, the first processing module is further used for determining a target angle sequence according to the synchronous control signal, determining a measured angle of each joint according to the angle monitoring information, calculating error information of the measured angle of each joint and the target angle sequence, and adjusting a driving current and a heating time length of each shape memory alloy spring based on the error information by using a PID algorithm.

4. The real-time human interaction bionic hand device of claim 2, wherein, The flexible matrix layer comprises a support matrix sublayer, a first elastic sublayer and a second elastic sublayer which are sequentially stacked, the feedback driving layer is embedded in the first elastic sublayer, and the control sensing layer is embedded in the second elastic sublayer.

5. The real-time human-interactive bionic hand apparatus of claim 2, wherein, The flexible matrix layer comprises a finger area and a palm area, the finger area adopts an inner recessed hexagonal reentrant unit structure, and the palm area adopts an inner recessed triangular reentrant unit structure.

6. The real-time human interaction bionic hand device of claim 1, wherein, The first driving signal is a PWM signal, and the first processing module changes a vibration mode by modulating a frequency and a duty cycle of the first driving signal.

7. The real-time human-interactive bionic hand apparatus of claim 1, wherein, ​ 8. The real-time human-interactive bionic hand apparatus of claim 7, wherein, The feedback driving layer further comprises a temperature sensing element for monitoring the working temperature of the shape memory alloy driving unit in real time; The second processing module is further configured to receive detection information of the temperature sensing element, and decrease a duty cycle of a target first driving signal to a preset value when it is determined that a temperature of a target shape memory alloy driving unit exceeds a preset temperature threshold, wherein the target first driving signal is a signal output to the target shape memory alloy driving unit.

9. The real-time human-interactive bionic hand apparatus of claim 1, wherein, The support framework layer comprises metacarpal bones and at least one phalanx, and each phalanx is movably connected to the metacarpal bones; The execution sensing layer comprises an angle sensing unit and a Bragg fiber grating sensing unit, the angle sensing unit is arranged at each joint of the phalanges, and the Bragg fiber grating sensing unit is arranged inside the bionic skin layer, and the measuring points of the Bragg fiber grating sensing unit correspond to cover the metacarpal bones and the phalanges.

10. The real-time human-interactive bionic hand apparatus of claim 9, wherein, Each measuring point is arranged with a group of Bragg fiber gratings, each group of Bragg fiber gratings comprises two Bragg fiber gratings with different center wavelengths, one Bragg fiber grating is directly arranged in the bionic skin layer and is used for sensing superimposed information of strain and temperature, and the other Bragg fiber grating is arranged in a strain isolation woolen tube to realize strain isolation.

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