Tactile feedback array system for simulating somatosensory roughness based on vibration mode and working method

Abstract

The invention provides a tactile feedback array system for simulating somatosensory roughness based on a vibration mode and a working method, and the system comprises a PDMS substrate layer which is used for providing flexible support; the piezoelectric actuating unit is integrated on the PDMS substrate layer and is used for outputting a multi-frequency vibration signal; the inertial measurement unit is fixed on the PDMS substrate layer and is used for acquiring the movement speed and acceleration information of the hand of the user in real time; the driver board is connected with the piezoelectric actuating unit and the inertial measurement unit through wires, generates vibration control parameters according to the movement speed, the acceleration and a target material roughness model, and drives the piezoelectric actuating unit to output a corresponding vibration mode; the Bluetooth communication module is arranged in the driver board and is used for communicating with an external host, receiving a vibration parameter instruction sent by the host and transmitting the vibration parameter instruction to the driver board; the system senses the dynamic motion state of the hand through the inertial measurement unit, and realizes closed-loop simulation feedback of dynamic tactile roughness in combination with multi-frequency vibration driving of the piezoelectric actuating unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tactile feedback, in particular to a tactile feedback array system based on vibration mode simulation of somatosensory roughness and a working method. BACKGROUND

[0002] The key technology of the tactile feedback system is how to realize high-fidelity, real-time and scalable tactile feedback. The current implementation of tactile feedback mainly includes three categories: single-point vibration feedback, array motor vibration feedback and piezoelectric actuation-based tactile feedback.

[0003] The existing single-point vibration feedback system has the advantages of simple structure, low cost and easy implementation, but it cannot meet the multi-point or high-resolution tactile interaction requirements because it only outputs vibration at a single point. The array motor vibration feedback system integrates multiple micro vibration motors on a flexible substrate to form a multi-point tactile array, which has good flexibility and adaptability, can cover a larger human surface, and can realize spatial distribution of tactile information. However, due to the size limitation and response time of the motor, it is difficult to realize high-frequency, fast-response complex tactile patterns, and the energy consumption is high, which may cause comfort problems during long-term wear.

[0004] The patent with application number CN202310808852.2 discloses an expandable array tactile feedback system and method. The system integrates vibration motors on a flexible circuit board and uses vibration isolation rings, silicone encapsulation and other structures, and outputs adjustable PWM signals with a single-chip microcomputer and a PWM driver to realize multi-point vibration control. However, this scheme still has the following shortcomings: first, the vibration motor as an actuating element is limited by mechanical inertia, making it difficult to achieve high-frequency, multi-frequency mixed or fast-switching vibration output, and the tactile fine expression capability is insufficient; second, the structure based on the motor is limited in size when realizing local precise feedback, making it difficult to further miniaturize and integrate at high density; third, the vibration isolation ring and silicone encapsulation increase the overall thickness of the system, which is not conducive to the design of lighter, thinner and skin-friendly wearable devices. SUMMARY

[0005] In view of the defects in the prior art, the purpose of the present application is to provide a tactile feedback array system based on vibration mode simulation of somatosensory roughness and a working method.

[0006] The tactile feedback array system based on vibration mode simulation of somatosensory roughness provided by the present application comprises:

[0007] a PDMS substrate layer for providing flexible support;

[0008] a piezoelectric actuation unit integrated in a 3x3 array form on the PDMS substrate layer for outputting multi-frequency vibration signals;

[0009] An inertial measurement unit is fixed on the PDMS base layer to collect motion speed and acceleration information of the user's hand in real time;

[0010] A driver board is connected with the piezoelectric actuation unit and the inertial measurement unit through wires, receives the collected information of the inertial measurement unit, and generates vibration control parameters according to the motion speed, acceleration and target material roughness model to drive the piezoelectric actuation unit to output corresponding vibration modes;

[0011] A Bluetooth communication module is built in the driver board to communicate with an external host, receive vibration parameter instructions sent by the host and transmit them to the driver board;

[0012] The system realizes closed-loop simulation feedback of dynamic tactile roughness by sensing the dynamic motion state of the hand through the inertial measurement unit and combining the multi-frequency vibration driving of the piezoelectric actuation unit.

[0013] Preferably, the 3x3 array layout of the piezoelectric actuation unit is designed based on the two-point discrimination threshold principle of the human hand, covering the back of the hand or the palm, and realizing high-resolution local tactile feedback by independently controlling the vibration frequency, amplitude and phase of each piezoelectric unit.

[0014] Preferably, a signal processing module is integrated in the driver board to filter and extract features from the raw motion data collected by the inertial measurement unit;

[0015] The signal processing module sequentially performs the following steps:

[0016] The motion data is denoised using a Kalman filter algorithm;

[0017] Time domain features are extracted, including sliding speed mean and acceleration change rate;

[0018] Frequency domain features are extracted, including main vibration frequency and energy distribution;

[0019] The processed feature data are used to calculate the driving parameters of the piezoelectric actuation unit.

[0020] Preferably, the driver board receives target material roughness parameters sent by the host through the Bluetooth communication module, including vibration frequency range, amplitude threshold and phase adjustment strategy, and dynamically adjusts the vibration mode of the piezoelectric actuation unit in combination with the real-time motion data of the inertial measurement unit.

[0021] Preferably, the driver board calculates the output signal of each piezoelectric actuation unit according to the following formula:

[0022]

[0023] where s i(t) is the output signal of the i-th piezoelectric actuator, A i is the driving amplitude calculated according to the local tactile feedback intensity, f i is the vibration frequency corresponding to the tactile model output; is the adjustable phase for the coherent modulation of the adjacent units at the same time; t is time.

[0024] Preferably, the driver board determines the driving amplitude A of the piezoelectric actuation unit by using a position-weighted interpolation algorithm i , specifically comprising:

[0025] When the sliding position is detected to be located in a specific area of the array, activate the adjacent piezoelectric units;

[0026] Based on the Gaussian kernel function, the activated units are assigned with amplitude weighting, so that the units close to the sliding center have the maximum amplitude, and the edge units have decreasing amplitudes.

[0027] Preferably, the signal processing module further comprises a dynamic frequency modulation function, which matches the vibration frequency according to the hand sliding speed:

[0028] When the sliding speed is 0-10 cm / s, the driving frequency is 60-80 Hz, and the amplitude is 0.5g;

[0029] When the sliding speed is 10-15 cm / s, the driving frequency is 200-300 Hz, and the amplitude is greater than 1.5g.

[0030] Preferably, the vibration mode of the piezoelectric actuation unit includes two forms of continuous sine wave and short pulse, which are used to simulate smooth surface and rough surface respectively; wherein the smooth surface corresponds to low-frequency continuous vibration, and the rough surface corresponds to high-frequency pulse vibration.

[0031] Preferably, the PDMS base layer, piezoelectric actuation unit and inertial measurement unit together constitute a wearable somatosensory patch with a thickness of less than 2mm, which is attached to the surface of the user's hand skin, connected to the driver board through a flexible circuit, realizing non-inductive wearing and natural interaction.

[0032] The working method of the tactile feedback array system for simulating somatosensory roughness based on vibration mode provided by the application comprises the following steps:

[0033] Step 1: Real-time acquisition of the motion speed and acceleration information of the user's hand by the inertial measurement unit;

[0034] Step 2: Filtering and feature extraction of the motion speed and acceleration information to generate time-domain feature and frequency-domain feature data;

[0035] Step 3: Receive the target material roughness parameters sent by the external host through the Bluetooth communication module, combine the time domain characteristics and frequency domain characteristics data, and dynamically generate the vibration control parameters of the piezoelectric actuator unit;

[0036] Step 4: Activate adjacent units in the piezoelectric actuator array based on the hand sliding position, and assign the vibration amplitude of each unit according to the sliding position, where the amplitude of the units near the sliding center is the largest and the amplitude of the edge units decreases;

[0037] Step 5: Select the corresponding vibration mode according to the hand sliding speed and target material roughness level:

[0038] When the sliding speed is 0-10 cm / s, drive the piezoelectric actuator unit to vibrate with a low-frequency continuous sine wave to simulate a smooth surface;

[0039] When the sliding speed is 10-15 cm / s, drive the piezoelectric actuator unit to vibrate with a high-frequency short-time pulse to simulate a rough surface;

[0040] Step 6: Output multi-frequency vibration signals through the piezoelectric actuator unit, and combine the phase coordination modulation of adjacent units to realize high-resolution local tactile feedback;

[0041] Step 7: Continuously monitor the hand movement state, dynamically adjust the vibration frequency, amplitude and phase, and form a closed-loop feedback to match the user's action in real time;

[0042] Step 8: Support external host remote adjustment of vibration parameters through Bluetooth communication module, and extend to third-party device interaction.

[0043] Compared with the prior art, the present application has the following beneficial effects:

[0044] (1) By adopting the closed-loop coupling mechanism of "IMU sensing + roughness model + piezoelectric array", the problem of lack of real-time adaptive ability of traditional single-frequency or static vibration system in dynamic interaction is solved, and high-simulation tactile feedback based on hand movement state is realized;

[0045] (2) By adopting a 9-point array layout, combined with the two-point discrimination threshold principle of human hand, the problem of insufficient tactile resolution is solved, and the resolution ability of tactile details is significantly improved;

[0046] (3) By adopting a flexible substrate and a small-sized driving structure, the problem of wearing discomfort and bulky volume of traditional rigid systems is solved, and a more portable and comfortable wearable experience is realized;

[0047] (4) By supporting host remote control and real-time parameter adjustment, the problem of traditional offline control unable to adjust feedback according to user dynamics is solved, and the effect of flexible adaptation to different use scenarios is achieved;

[0048] (5) With an open control interface, it achieves good system scalability and can be further extended to various tactile interaction application fields such as virtual reality, remote collaboration, and rehabilitation training. Attached Figure Description

[0049] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0050] Figure 1 This is a schematic diagram of the tactile feedback array system for simulating tactile roughness based on vibration modes according to the present invention.

[0051] Wherein: 1-PDMS substrate, 2-piezoelectric actuation unit, 3-inertial measurement unit, 4-driver board. Detailed Implementation

[0052] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0053] Example

[0054] This invention proposes a tactile feedback array system based on vibration mode to simulate tactile roughness. Utilizing a coupling mechanism between multi-frequency vibration drive of a piezoelectric array and motion state perception, it can simulate the roughness of various materials and provide high-resolution, real-time tactile feedback. The system is compact, wearable, and suitable for natural interaction on the back of the hand or palm.

[0055] A tactile feedback array system based on vibration mode to simulate tactile roughness includes: a piezoelectric actuation array (3×3), an inertial measurement unit 3, and a driver board 4.

[0056] The piezoelectric actuation array includes a PDMS substrate 1 and piezoelectric actuation units 2. The inertial measurement unit 3 and the piezoelectric actuation units 2 are both located on the PDMS substrate 1. The inertial measurement unit 3 senses the user's hand movement speed and acceleration information in real time. The driver board 4 is connected to the piezoelectric actuation units 2 and the inertial measurement unit 3 via wires, receives their signals, and centrally controls the vibration output of all piezoelectric units. The driver board 4 communicates with the host computer via a Bluetooth communication module to receive signals and transmit them to the piezoelectric actuation units 2 for drive control, realizing simulation and feedback strategies for different roughnesses. When the perceived roughness is at a smooth level (such as glass), the fingertip slips... When the movement speed is medium to slow (0–10 cm / s), a low-amplitude, low-frequency continuous sine wave drives the piezoelectric actuator, enabling it to operate at low vibration intensity (0.5g) and maintain a vibration frequency between 60–80 Hz. When the perceived roughness is significantly rough (e.g., sandpaper), and the fingertip sliding speed is fast (10–15 cm / s), a short-time pulse and frequency modulation method drives the piezoelectric actuator array, enabling it to operate at high vibration intensity (>1.5g) and maintain a vibration frequency between 200–300 Hz. Utilizing the frequency response characteristics of the piezoelectric actuator, various sensory modes are synthesized by changing the frequency and duty cycle of the PWM signal. The host-side roughness model system generates corresponding multi-frequency vibration parameters based on information such as the target simulated material and hand speed, and transmits them to the driver board. The entire system constitutes a wearable somatosensory patch, achieving material texture simulation and dynamic feedback during the user's natural movement.

[0057] The driver board 4 acquires the hand motion information collected in real time by the inertial measurement unit 3, and calculates the corresponding vibration feedback parameters based on the speed and acceleration of the hand, thereby driving the piezoelectric actuation unit 2 to output a multi-frequency vibration signal that simulates roughness, thus realizing simulated feedback of the texture of the target material.

[0058] Furthermore, the driver board 4 communicates with the host via a Bluetooth communication module, receives vibration parameters generated by the host based on the target simulated material and the hand movement state, and transmits the vibration parameters to the piezoelectric actuation unit 2, controlling the piezoelectric actuation unit 2 to output the corresponding vibration mode.

[0059] Furthermore, the driver board 4 calculates the independent vibration output signal of each piezoelectric actuation unit 2 based on the hand movement velocity and acceleration information collected by the inertial measurement unit 3 and the vibration parameters received from the host, thereby achieving customized tactile feedback for different positions. The system uses a 3×3 array and needs to calculate the driving parameters (frequency f) of each piezoelectric unit based on the current finger position and target tactile information. i Strength A i The calculation formula is as follows:

[0060]

[0061] Where: s i (t) represents the output signal of the i-th piezoelectric actuator, A i f is the driving amplitude calculated based on the intensity of local tactile feedback. i To correspond to the vibration frequency output by the tactile model, For adjustable phase (used for coherent modulation during cooperative operation between adjacent units), t is time. For example, if the IMU detects that the sliding position is at the upper right corner of the array, then the array [1,2], [2,2], [2,3] is activated; position-weighted interpolation (such as a Gaussian kernel) is used to determine the A of these units. i If the perception is "rough", the corresponding f i The value is relatively high, A i Increase.

[0062] Furthermore, it also includes a signal processing module, which is located between the inertial measurement unit 3 and the driver board 4. The signal processing module is used to filter and extract features from the raw motion signals acquired by the inertial measurement unit 3. Kalman filtering is used for the inertial measurement data to improve the accuracy of motion estimation. Subsequently, the time domain features (such as mean and rate of change) and frequency domain features (such as dominant frequency and energy distribution) of the signal are extracted and provided to the driver board 4 for vibration control, thereby improving the accuracy and real-time performance of tactile feedback.

[0063] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this application.

[0064] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0065] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A tactile feedback array system based on vibration mode to simulate perceptual roughness, characterized in that, include: PDMS substrate (1) is used to provide flexible support; The piezoelectric actuation unit (2) is integrated on the PDMS substrate (1) in a 3×3 array and is used to output multi-frequency vibration signals; An inertial measurement unit (3) is fixed on the PDMS base layer (1) to collect the user's hand movement speed and acceleration information in real time. The driver board (4) is connected to the piezoelectric actuation unit (2) and the inertial measurement unit (3) via wires. It receives the information collected by the inertial measurement unit (3) and generates vibration control parameters based on the motion speed, acceleration and target material roughness model, and drives the piezoelectric actuation unit (2) to output the corresponding vibration mode. The Bluetooth communication module is built into the driver board (4) and is used to communicate with an external host, receive vibration parameter instructions sent by the host and transmit them to the driver board (4); The system senses the dynamic motion state of the hand through the inertial measurement unit (3) and combines it with the multi-frequency vibration drive of the piezoelectric actuation unit (2) to realize closed-loop simulation feedback of dynamic tactile roughness.

2. The tactile feedback array system based on vibration mode to simulate tactile roughness according to claim 1, characterized in that, The 3×3 array layout of the piezoelectric actuation unit (2) is designed based on the principle of two-point discrimination threshold of human hand, covering the back of the hand or the palm. By independently controlling the vibration frequency, amplitude and phase of each piezoelectric unit, high-resolution local tactile feedback is achieved.

3. The tactile feedback array system based on vibration mode to simulate tactile roughness according to claim 1, characterized in that, It also includes a signal processing module, which is integrated into the driver board (4) for filtering and feature extraction of the raw motion data collected by the inertial measurement unit (3); The signal processing module performs the following steps in sequence: The Kalman filter algorithm is used to denoise the motion data; Extract time-domain features, including the mean sliding velocity and the rate of change of acceleration; Extract frequency domain features, including principal vibration frequencies and energy distribution; The processed feature data is used to calculate the driving parameters of the piezoelectric actuation unit (2).

4. The tactile feedback array system based on vibration mode to simulate tactile roughness according to claim 1, characterized in that, The driver board (4) receives the target material roughness parameters sent by the host through the Bluetooth communication module, including the vibration frequency range, amplitude threshold and phase adjustment strategy, and dynamically adjusts the vibration mode of the piezoelectric actuation unit (2) in conjunction with the real-time motion data of the inertial measurement unit (3).

5. The tactile feedback array system based on vibration mode to simulate tactile roughness according to claim 1, characterized in that, The driver board (4) calculates the output signal of each piezoelectric actuation unit (2) according to the following formula: Among them, s i (t) represents the output signal of the i-th piezoelectric actuator, A i f is the driving amplitude calculated based on the intensity of local tactile feedback. i This corresponds to the vibration frequency output by the tactile model; The phase is adjustable and used for coherent modulation when adjacent units cooperate and coordinate; t is time.

6. The tactile feedback array system for simulating tactile roughness based on vibration modes according to claim 5, characterized in that, The driver board (4) uses a position-weighted interpolation algorithm to determine the driving amplitude A of the piezoelectric actuation unit (2). i Specifically, it includes: When the sliding position is detected to be located in a specific area of ​​the array, the adjacent piezoelectric unit is activated; The activation units are weighted by a Gaussian kernel function, so that the units near the sliding center have the largest amplitude and the edge units have decreasing amplitude.

7. The tactile feedback array system based on vibration mode to simulate tactile roughness according to claim 3, characterized in that, The signal processing module further includes a dynamic frequency modulation function, which matches the vibration frequency according to the hand sliding speed: When the sliding speed is 0 to 10 cm / s, the driving frequency is 60 to 80 Hz and the amplitude is 0.5g. When the sliding speed is 10-15 cm / s, the driving frequency is 200-300 Hz and the amplitude is greater than 1.5g.

8. The tactile feedback array system for simulating tactile roughness based on vibration modes according to claim 1, characterized in that, The vibration modes of the piezoelectric actuation unit (2) include two forms: continuous sine wave and short pulse, which are used to simulate smooth surface and rough surface, respectively; among them, smooth surface corresponds to low-frequency continuous vibration, and rough surface corresponds to high-frequency pulse vibration.

9. The tactile feedback array system for simulating tactile roughness based on vibration modes according to claim 1, characterized in that, The PDMS base layer (1), piezoelectric actuation unit (2) and inertial measurement unit (3) together constitute a wearable haptic patch with a thickness of less than 2 mm. It is attached to the surface of the user's hand skin and connected to the driver board (4) through a flexible circuit to achieve non-sensory wearing and natural interaction.

10. A method for operating a tactile feedback array system based on vibration mode to simulate tactile roughness according to any one of claims 1 to 9, characterized in that, Includes the following steps: Step 1: Collect real-time information on the user's hand movement speed and acceleration using an inertial measurement unit; Step 2: Filter and extract features from the motion velocity and acceleration information to generate time-domain and frequency-domain feature data; Step 3: Receive the target material roughness parameters sent by the external host via Bluetooth communication module, and dynamically generate the vibration control parameters of the piezoelectric actuator by combining time-domain and frequency-domain characteristic data; Step 4: Activate adjacent units in the piezoelectric actuation array based on the hand sliding position, and assign the vibration amplitude of each unit according to the sliding position, with the unit closer to the sliding center having the largest amplitude and the edge units having decreasing amplitude. Step 5: Select the corresponding vibration mode based on the hand sliding speed and the roughness level of the target material: When the sliding speed is 0 to 10 cm / s, the piezoelectric actuator unit is driven to vibrate with a low-frequency continuous sinusoidal wave to simulate a smooth surface. When the sliding speed is 10-15 cm / s, the piezoelectric actuator unit is driven to simulate a rough surface by high-frequency short-time pulse vibration. Step 6: Output multi-frequency vibration signals through the piezoelectric actuation unit and combine them with the phase coordination modulation of adjacent units to achieve high-resolution local tactile feedback; Step 7: Continuously monitor hand movement and dynamically adjust vibration frequency, amplitude, and phase to form a closed-loop feedback to match user actions in real time; Step 8: Support remote adjustment of vibration parameters by an external host via Bluetooth communication module, and extend to interaction with third-party devices.

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