Adaptive haptic feedback method and system for touchscreens

Abstract

The application relates to the technical field of touch screens, and discloses a self-adaptive tactile feedback method and system for a touch screen. The self-adaptive tactile feedback method for the touch screen comprises the following steps: acquiring a contact pressure distribution data set; determining a compact contact area; locating a peak point of a contact pressure distribution map, and calculating an offset vector of the peak point relative to a geometric center of the compact contact area; establishing a polar coordinate system and dividing a sector analysis area according to the peak point and the offset vector, and acquiring a pressure attenuation gradient value and a pressure mirror similarity of the compact contact area according to a pressure data sequence; determining a contact position of the compact contact area according to an offset distance, the pressure attenuation gradient value and the pressure mirror similarity, and generating a corresponding contact position label; and matching a corresponding tactile feedback mode according to the contact position label. The scheme can solve the problem of low contact position recognition accuracy of the touch screen, and further improve the matching degree of the feedback mode of the touch screen and the user's intention.

Description

Technical Field

[0001] This application relates to the field of touch screen technology, and in particular to an adaptive haptic feedback method and system for touch screens. Background Technology

[0002] Touchscreen technology is widely used in terminal devices such as smartphones and tablets. As a core function to enhance the human-computer interaction experience, haptic feedback can provide differentiated feedback based on touch operations, directly determining the user experience and user satisfaction of the device.

[0003] In existing technologies, touchscreens incorporate tactile sensors that can collect signals such as pressure and area of ​​contact. The touchscreen can then recognize touch operations based on these signals and provide corresponding vibration or force feedback. However, current touchscreen tactile feedback systems primarily rely on the single-dimensional parameter of touch contact area to determine the operation type, failing to accurately distinguish between different contact points such as the palm, fingertips, or finger pads. This results in a mismatch between the tactile feedback mode and the user's actual operational intent.

[0004] In other words, existing tactile feedback methods have low accuracy in identifying contact points, which leads to a mismatch between the feedback mode and the user's actual operating intention. Summary of the Invention

[0005] This application provides an adaptive haptic feedback method and system for touch screens to improve the accuracy of contact part recognition in touch screen haptic feedback, thereby enabling the haptic feedback mode to accurately match the user's actual operation intention.

[0006] According to one aspect of this application, an adaptive haptic feedback method for a touchscreen is provided, comprising:

[0007] Acquire the pressure signal on the surface of the touch screen, and filter the pressure signal to obtain a contact pressure distribution dataset;

[0008] Extract the outer rectangular boundary of the contact area from the contact pressure distribution dataset, and determine the compact contact area based on the aspect ratio of the outer rectangular boundary;

[0009] The contact pressure distribution dataset of the compact contact area is divided into grids, and a contact pressure distribution map is generated based on the pressure value of each grid cell. The peak point of the contact pressure distribution map is located, and the offset vector of the peak point relative to the geometric center of the compact contact area is calculated. The offset vector includes an offset distance and an offset direction.

[0010] A polar coordinate system is established based on the peak point and the offset vector, and a sector analysis area is divided. Pressure data sequences of equally spaced rings within the sector analysis area are extracted. The pressure attenuation gradient value and pressure mirror similarity of the compact contact area are obtained based on the pressure data sequences.

[0011] The contact points of the compact contact area are determined based on the offset distance, the pressure attenuation gradient value, and the pressure mirror similarity, and corresponding contact point labels are generated.

[0012] The corresponding tactile feedback mode is matched according to the label of the contact area.

[0013] Optionally, the touchscreen surface is provided with multiple pressure detection points. The step of acquiring the pressure signal from the touchscreen surface and filtering the pressure signal to obtain a contact pressure distribution dataset includes:

[0014] Acquire the pressure signals at each pressure detection point on the surface of the touch screen;

[0015] The pressure signal is processed using an exponential moving average algorithm to obtain the contact pressure distribution dataset.

[0016] Optionally, the step of extracting the circumscribed rectangular boundary of the contact area from the contact pressure distribution dataset and determining the compact contact area based on the aspect ratio of the circumscribed rectangular boundary includes:

[0017] Points in the contact pressure distribution dataset that are greater than a preset pressure value are identified as effective contact areas.

[0018] Using the detection coordinate system of the touch screen as a reference, obtain the maximum value of the horizontal coordinate, the minimum value of the horizontal coordinate, the maximum value of the vertical coordinate, and the minimum value of the vertical coordinate of all pressure detection points in the effective contact area;

[0019] Construct the smallest rectangle that encloses the effective contact area based on the maximum and minimum values ​​of the horizontal coordinate, the maximum and minimum values ​​of the vertical coordinate, and the smallest rectangle is the boundary of the circumscribed rectangle;

[0020] The contact area whose aspect ratio of the circumscribed rectangle is within a preset aspect ratio range is defined as the compact contact area.

[0021] Optionally, the step of dividing the contact pressure distribution dataset of the compact contact area into grids, generating a contact pressure distribution map based on the pressure value of each grid cell, locating the peak point of the contact pressure distribution map, and calculating the offset vector of the peak point relative to the geometric center of the compact contact area includes:

[0022] The grid cells are divided according to the pixel resolution of the touchscreen;

[0023] The pressure value within each grid cell is subjected to bilinear interpolation to generate a continuous contact pressure distribution map;

[0024] By iterating through the pressure values ​​of all grid cells in the contact pressure distribution map, the target grid cell with the largest pressure value is selected, and the location with the largest pressure value in the target grid cell is the peak point.

[0025] Based on the detection coordinate system, the coordinates of the peak point and the coordinates of the geometric center of the compact contact area are extracted respectively, and the offset distance and offset direction of the peak point relative to the geometric center of the compact contact area are calculated.

[0026] Optionally, the step of establishing a polar coordinate system and dividing the sector analysis region based on the peak point and the offset vector, extracting the pressure data sequence of equally spaced rings within the sector analysis region, and obtaining the pressure attenuation gradient value and pressure mirror similarity of the compact contact region based on the pressure data sequence includes:

[0027] A polar coordinate system is established with the peak point as the origin of polar coordinates and the direction of the offset vector as the polar coordinate axis direction; wherein, the polar radius is the distance from the origin of polar coordinates to any pressure detection point in the compact contact area, and the polar angle is the angle between the offset vector and the ray pointing from the origin of polar coordinates to the pressure detection point;

[0028] According to the preset polar angle interval, the compact contact area is divided into multiple sector-shaped analysis areas in the polar coordinate system, and then each sector-shaped analysis area is divided into multiple equally spaced rings according to the preset radial spacing;

[0029] Extract the pressure data sequence corresponding to the equally spaced rings within each of the sector analysis regions, calculate the radial rate of change of pressure in the equally spaced rings, and obtain the pressure attenuation gradient value;

[0030] A symmetrical sector analysis region with the line containing the offset vector as the axis of symmetry is selected, and the cosine similarity of the pressure data sequence of the equally spaced rings in each layer of the symmetrical sector analysis region is calculated to obtain the pressure mirror similarity.

[0031] Optionally, determining the contact portion of the compact contact region based on the offset distance, the pressure attenuation gradient value, and the pressure mirror similarity, and generating a corresponding contact portion label, includes:

[0032] If the offset distance is less than or equal to the first preset offset distance, and the pressure attenuation gradient value is greater than or equal to the first preset attenuation gradient value, and the pressure mirror similarity is greater than or equal to the first preset mirror similarity, then the compact contact area is determined to be a fingertip contact, and a fingertip contact label is generated.

[0033] Optionally, determining the contact portion of the compact contact region based on the offset distance, the pressure attenuation gradient value, and the pressure mirror similarity, and generating a corresponding contact portion label, further includes:

[0034] If the first preset offset distance < the offset distance ≤ the second preset offset distance, and the second preset attenuation gradient value ≤ the pressure attenuation gradient value < the first preset attenuation gradient value, and the second preset mirror similarity ≤ the pressure mirror similarity < the first preset mirror similarity, then the compact contact area is determined to be fingertip contact, and a fingertip contact label is generated.

[0035] Optionally, determining the contact portion of the compact contact region based on the offset distance, the pressure attenuation gradient value, and the pressure mirror similarity, and generating a corresponding contact portion label, further includes:

[0036] If the offset distance is greater than the second preset offset distance, or the pressure attenuation gradient value is less than the second preset attenuation gradient value, or the pressure mirror similarity is less than the second preset mirror similarity, then the compact contact area is determined to be an atypical contact, and an atypical contact label is generated.

[0037] Optionally, matching the corresponding tactile feedback mode based on the contact area label includes:

[0038] If the fingertip touches the tag, the click vibration mode is activated;

[0039] If the fingertip is detected to be in contact with the tag, the rebound vibration mode is activated;

[0040] If the atypical contact tag is detected, the no-feedback mode is maintained.

[0041] According to another aspect of this application, an adaptive haptic feedback system for a touchscreen is provided, comprising:

[0042] The signal acquisition module is used to acquire the pressure signal on the surface of the touch screen and filter the pressure signal to obtain a contact pressure distribution dataset.

[0043] The regional screening module is used to extract the outer rectangular boundary of the contact area from the contact pressure distribution dataset, and determine the compact contact area based on the aspect ratio of the outer rectangular boundary.

[0044] The offset vector acquisition module is used to divide the contact pressure distribution dataset of the compact contact area into grids, generate a contact pressure distribution map based on the pressure value of each grid cell, locate the peak point of the contact pressure distribution map, and calculate the offset vector of the peak point relative to the geometric center of the compact contact area; wherein, the offset vector includes an offset distance and an offset direction;

[0045] The pressure analysis module is used to establish a polar coordinate system and divide the sector analysis area based on the peak point and the offset vector, extract the pressure data sequence of equally spaced rings in the sector analysis area, and obtain the pressure attenuation gradient value and pressure mirror similarity of the compact contact area based on the pressure data sequence.

[0046] The contact location determination module is used to determine the contact location of the compact contact area based on the offset distance, the pressure attenuation gradient value, and the pressure mirror similarity, and generate corresponding contact location labels.

[0047] The tactile feedback module is used to match the corresponding tactile feedback mode according to the label of the contact area.

[0048] The technical solution of this application first identifies compact contact areas through preliminary screening to eliminate obvious environmental interference or accidental touches. Next, a sector-shaped analysis area is established to analyze the pressure attenuation gradient value and pressure mirror similarity within the compact contact area, thereby accurately determining the contact points and generating corresponding labels. Finally, haptic feedback patterns are matched based on these contact point labels, thereby improving the quality of human-computer interaction. Therefore, the technical solution provided by this application can solve the problem of low accuracy in touchscreen contact point recognition, thus improving the matching degree between touchscreen feedback patterns and user intentions.

[0049] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments 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.

[0051] Figure 1 A flowchart illustrating an adaptive haptic feedback method for a touchscreen provided in an embodiment of this application;

[0052] Figure 2A flowchart illustrating another adaptive haptic feedback method for a touchscreen provided in an embodiment of this application;

[0053] Figure 3 A flowchart illustrating another adaptive haptic feedback method for a touchscreen provided in an embodiment of this application;

[0054] Figure 4 This is a schematic diagram of the structure of an adaptive haptic feedback system for a touch screen provided in an embodiment of this application. Detailed Implementation

[0055] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0056] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0057] Figure 1 This is a flowchart illustrating an adaptive haptic feedback method for a touchscreen, provided in an embodiment of this application. This embodiment is applicable to human-computer interaction with touchscreens. The method can be executed by an adaptive haptic feedback system for the touchscreen, which can be implemented in hardware and / or software. This adaptive haptic feedback system can be configured in a device equipped with a touchscreen. Figure 1 As shown, the method includes:

[0058] S110. Obtain the pressure signal on the surface of the touch screen, and filter the pressure signal to obtain the contact pressure distribution dataset.

[0059] Specifically, the pressure signal on the touchscreen surface can be measured by a haptic sensor. The pressure signal can include the coordinates and pressure intensity data of each point within the contact area. Filtering refers to the technique of denoising and enhancing the pressure signal acquired by the haptic sensor, aiming to eliminate environmental interference and sensor noise, and retain the true user contact signal. The contact pressure distribution dataset refers to the structured pressure data set obtained after filtering, representing the spatial distribution of pressure on the touchscreen surface at a specific moment, and can be stored in matrix or grid form.

[0060] In this embodiment, the pressure signal is the initial input for physical interaction on the touchscreen, and its signal quality directly affects the final feedback accuracy. Filtering can eliminate environmental noise, sensor background noise, and instantaneous false touch signals in the pressure signal, ensuring that the obtained contact pressure distribution dataset reflects the true user intent and laying a data foundation for subsequent steps.

[0061] S120. Extract the outer rectangular boundary of the contact area from the contact pressure distribution dataset, and determine the compact contact area based on the aspect ratio of the outer rectangular boundary.

[0062] Specifically, the circumscribed rectangle refers to the smallest orthogonal rectangle that can completely enclose all contact points on the contact screen. The aspect ratio refers to the ratio of the length to the width of the circumscribed rectangle. A compact contact area refers to a contact area with an aspect ratio within a certain range. Compact contact areas are characterized by high morphological symmetry and high spatial concentration, effectively eliminating environmental interference from contaminants such as water droplets and dust, as well as non-target human contact such as hand edges or animal paws.

[0063] In this embodiment, compared with the traditional use of contour fitting, fitting the contact area with a circumscribed rectangular boundary can reduce the complexity of subsequent calculations. Furthermore, by using aspect ratio to initially screen the shape of the contact area, a compact contact area is obtained, which can effectively eliminate obvious environmental interference or other causes of accidental touches, thus improving the sensitivity of tactile feedback.

[0064] S130. The contact pressure distribution dataset of the compact contact area is divided into grids. A contact pressure distribution map is generated based on the pressure value of each grid cell. The peak point of the contact pressure distribution map is located, and the offset vector of the peak point relative to the geometric center of the compact contact area is calculated. The offset vector includes the offset distance and the offset direction.

[0065] Specifically, gridding refers to the data processing procedure of dividing a compact contact area into several grid cells. Each grid cell corresponds to a pressure value. The size of the grid cell should match the resolution of the tactile sensor to ensure that the grid cell can fully reflect the pressure signal collected by the tactile sensor and avoid errors caused by insufficient resolution. The contact pressure distribution map is a graphical visualization used to display the pressure values ​​of each grid cell. For example, the contact pressure distribution map can use color gradients to represent different pressure levels. The peak point refers to the point with the highest pressure value in the contact pressure distribution map. The geometric center refers to the center point of the compact contact area. For example, the geometric center can be the average of the coordinates of all boundary points in the compact contact area. The offset vector refers to the vector from the geometric center to the peak point, including the offset distance and offset direction. The offset distance is the straight-line distance from the geometric center to the peak point. The offset direction is the direction from the geometric center to the peak point, which can be represented by an angle or a vector.

[0066] In this embodiment, the contact pressure distribution dataset of the compact contact area is divided into multiple small grid cells, so that each cell can represent the pressure value in a specific area, which helps to analyze the local pressure distribution characteristics in detail. Calculating the peak point and offset vector in the contact pressure distribution map can determine the position of the peak point relative to the center of the contact area, providing a data basis for subsequent judgment of the degree of force attenuation and mirror similarity.

[0067] S140. Establish a polar coordinate system based on the peak point and offset vector and divide the sector analysis area. Extract the pressure data sequence of equally spaced rings within the sector analysis area. Obtain the pressure attenuation gradient value and pressure mirror similarity of the compact contact area based on the pressure data sequence.

[0068] Specifically, the sector analysis region refers to a sector-shaped area divided at a certain angle with the peak point as the center in the polar coordinate system. Establishing the sector analysis region facilitates detailed analysis of local pressure. Equally spaced rings refer to multiple rings evenly spaced within the sector analysis region. Each ring represents a specific radius area. The pressure data sequence refers to the sequence composed of the extracted pressure values ​​within each equally spaced ring, used to analyze pressure variations. The pressure attenuation gradient value represents the degree of pressure attenuation with the ring gradient, which can be used to determine the spatial trend of pressure variation in the compact contact area, thereby understanding the uniformity of the tactile feedback effect. Pressure mirror similarity measures the similarity of pressure distribution characteristics between different sector analysis intervals within the compact contact area.

[0069] In this embodiment, a reference is set in the polar coordinate system based on the peak point and offset vector to further subdivide the contact area, facilitating overall and local pressure analysis within the compact contact area. Then, extracting the data sequence of equally spaced rings provides a more intuitive reflection of pressure variation patterns, improving the accuracy and reliability of pressure distribution characteristic analysis. Furthermore, determining the pressure attenuation gradient value allows for the assessment of pressure attenuation with distance; calculating the pressure mirror similarity can be used to compare the consistency of pressure characteristics between different contact areas. After obtaining the pressure attenuation gradient value and mirror similarity, the feedback mode can be optimized for different contact types and states, providing users with a more personalized and comfortable experience during interaction.

[0070] S150. Determine the contact points of the compact contact area based on the offset distance, pressure attenuation gradient value, and pressure mirror similarity, and generate corresponding contact point labels.

[0071] Specifically, a contact point refers to the specific part used to contact a compact contact area. For example, this contact point could be a tool such as a fingertip, fingertip, or stylus. A contact point label refers to an identifier for the contact point.

[0072] In this embodiment, accurately determining the contact type of a compact contact area and generating a label for that area helps to gain a deeper understanding of the details of user interaction. This process not only improves the response speed of haptic feedback but also adjusts the feedback mode according to different contact types to better adapt to user needs.

[0073] S160. Match the corresponding tactile feedback mode according to the label of the contact area.

[0074] Specifically, haptic feedback mode refers to the feedback provided by the touchscreen for different contact points. For example, setting different haptic feedback for different contact points, such as fingertips and finger pads, allows users to experience a more natural and intuitive interactive experience when using the device.

[0075] In this embodiment of the application, by selecting or adjusting a suitable tactile feedback mode based on the generated contact area labels, tactile feedback matching neural perception is provided for different contact areas, which can effectively improve user experience and interaction quality.

[0076] The technical solution of this application first identifies compact contact areas through preliminary screening to eliminate obvious environmental interference or accidental touches. Next, a sector-shaped analysis area is established to analyze the pressure attenuation gradient value and pressure mirror similarity within the compact contact area, thereby accurately determining the contact points and generating corresponding labels. Finally, haptic feedback patterns are matched based on these contact point labels, thereby improving the quality of human-computer interaction. Therefore, the technical solution of this application can solve the problem of low accuracy in touchscreen contact point recognition, thereby improving the matching degree between touchscreen feedback patterns and user intentions.

[0077] Figure 2 A flowchart illustrating another adaptive haptic feedback method for a touchscreen provided in this application embodiment. Based on the above embodiments, as... Figure 2 As shown, optionally, the adaptive haptic feedback method of the touchscreen includes:

[0078] S201. Obtain the pressure signals of each pressure detection point on the surface of the touch screen.

[0079] Specifically, pressure detection points refer to specific locations on a touchscreen that can be detected to measure the pressure applied by the user. These pressure detection points can be equipped with haptic sensors or pressure sensors to accurately capture touch states.

[0080] For example, an array of 64×64 pressure-sensitive sensor units can be used to acquire pressure signals from touch events. The array has a resolution of 1 mm, and each sensor unit can output a digital pressure intensity value from 0 to 1023 when touched; these values ​​are the measured pressure signal.

[0081] S202. The pressure signal is processed using the exponential moving average algorithm to obtain the contact pressure distribution dataset.

[0082] Specifically, the Exponential Moving Average (EMA) algorithm is a weighted moving average algorithm that assigns an exponentially decaying weight to each observation in time series data, making newer data have a greater impact on the average.

[0083] In this embodiment of the application, by using the exponential moving average algorithm to process the pressure signal, the data can be effectively smoothed, the influence of noise can be reduced, and a continuous and accurate contact pressure distribution dataset can be obtained.

[0084] S203. Determine the points in the contact pressure distribution data that are greater than the preset pressure value as the effective contact area.

[0085] Specifically, the preset pressure value refers to the pressure threshold set based on the touchscreen's pressure sensitivity. Points with pressure values ​​below the preset pressure value are considered invalid or insignificant contact points. The effective contact area refers to the region in the contact pressure distribution dataset where the pressure value is greater than the preset pressure value, representing the user's effective touch area.

[0086] In this embodiment of the application, excluding invalid contact points with pressure values ​​below a preset value can reduce false detections and false triggers, and improve the system's accuracy in recognizing the user's true intentions.

[0087] S204. Using the detection coordinate system of the touch screen as a reference, obtain the maximum and minimum values ​​of the horizontal coordinate, the maximum and minimum values ​​of the vertical coordinate of all pressure detection points in the effective contact area.

[0088] Specifically, the touchscreen's detection coordinate system refers to the coordinate system used to describe the position of various points on the touchscreen. This detection coordinate system is typically a two-dimensional coordinate system, with the horizontal axis (X-axis) representing the horizontal direction and the vertical axis (Y-axis) representing the vertical direction. Each pressure detection point has a unique coordinate value. The maximum value of the horizontal axis is the horizontal position of the rightmost point within the effective contact area. The minimum value of the horizontal axis is the horizontal position of the leftmost point within the effective contact area. The maximum value of the vertical axis is the vertical position of the topmost point within the effective contact area. The minimum value of the vertical axis is the vertical position of the bottommost point within the effective contact area.

[0089] S205. Construct the smallest rectangle that encloses the effective contact area based on the maximum and minimum values ​​of the horizontal coordinate, the maximum and minimum values ​​of the vertical coordinate, and the smallest rectangle is the boundary of the circumscribed rectangle.

[0090] For example, if the maximum value of the horizontal coordinate is X_max and the minimum value of the horizontal coordinate is X_min, and the maximum value of the vertical coordinate is Y_max and the minimum value of the vertical coordinate is Y_min, then the coordinates of the four vertices of the minimum rectangle are (X_min, Y_min), (X_max, Y_min), (X_max, Y_max), and (X_min, Y_max).

[0091] S206. The contact area whose aspect ratio of the circumscribed rectangle is within the preset aspect ratio range is defined as the compact contact area.

[0092] Specifically, the preset aspect ratio range refers to the range of aspect ratios set according to the actual needs of the compact contact area.

[0093] For example, fingertip contact is approximately circular, with an aspect ratio close to 1. Finger pad contact is approximately elliptical, with its length and width possibly slightly less than or slightly greater than 1, and the difference from fingertip contact is not significant. The palm is distinctly elongated, and its preset aspect ratio may exceed 1.5. Therefore, the preset aspect ratio can be set to 0.8-1.2. If the calculated circumscribed rectangle for a certain contact event has a length of 2.5 cm and a width of 1 cm, its aspect ratio 2.5 / 1 = 2.5, far exceeding the contact range of the fingertip and finger pad, then the contact area corresponding to this contact event does not belong to a compact contact shape.

[0094] S207. Divide the grid cells according to the pixel resolution of the touch screen.

[0095] For example, the grid size can be set to be equal to the size of a single pixel. This provides the highest grid precision and is suitable for scenarios requiring detailed pressure distribution, but it involves a large computational load. Alternatively, the grid size can be set to be larger than the size of a single pixel, merging multiple pixels into one grid cell. This setting reduces the amount of data and improves the algorithm's running speed.

[0096] In this embodiment, the grid is precisely divided according to the resolution of the touch screen, which ensures that each small cell can accurately reflect the local pressure distribution characteristics and improve the accuracy of the analysis.

[0097] S208. Perform bilinear interpolation on the pressure values ​​within each grid cell to generate a continuous contact pressure distribution map.

[0098] Specifically, bilinear interpolation involves calculating the pressure value at the center of a grid cell by analyzing the values ​​at four known points within that cell. For example, these four known points could be the pressure values ​​at the four vertices of the grid cell. This process allows for a smooth transition of pressure data in two-dimensional space, generating a continuous contact pressure distribution map.

[0099] S209. Traverse the pressure values ​​of all grid cells in the contact pressure distribution map, and select the target grid cell with the largest pressure value. The position with the largest pressure value in the target grid cell is the peak point.

[0100] Specifically, the target grid cell refers to the grid cell corresponding to the point with the highest pressure value.

[0101] S210. Based on the detection coordinate system, extract the coordinates of the peak point and the coordinates of the geometric center of the compact contact area, and calculate the offset distance and offset direction of the peak point relative to the geometric center of the compact contact area.

[0102] Specifically, the geometric center of the compact contact area can be the centroid of its circumscribed rectangle. If the coordinates of the peak point are (x1, y1) and the coordinates of the geometric center are (x2, y2), then the offset distance d can be calculated using the following formula:

[0103] The offset direction can be expressed as an offset direction angle. Indicates the offset direction angle. The calculation formula is:

[0104]

[0105] The offset vector includes the offset distance and the offset direction.

[0106] S211. Establish a polar coordinate system based on the peak point and offset vector and divide the sector analysis area. Extract the pressure data sequence of equally spaced rings within the sector analysis area. Obtain the pressure attenuation gradient value and pressure mirror similarity of the compact contact area based on the pressure data sequence.

[0107] S212. Determine the contact points of the compact contact area based on the offset distance, pressure attenuation gradient value, and pressure mirror similarity, and generate corresponding contact point labels.

[0108] S213. Match the corresponding tactile feedback mode according to the label of the contact area.

[0109] The technical solution of this application employs an exponential moving average algorithm to process the raw pressure signals from multiple pressure detection points on the touchscreen surface, solving the problem of inaccurate contact area identification caused by noise interference in the raw pressure signals. By filtering out compact contact areas based on the aspect ratio of the circumscribed rectangle, obvious erroneous operations can be eliminated, retaining only data close to the user's actual operation, thus reducing subsequent calculation steps. Furthermore, through gridding based on the touchscreen pixel resolution and bilinear interpolation, discrete pressure data is transformed into a high-resolution continuous pressure distribution map, significantly improving the spatial representation accuracy of the contact area.

[0110] Figure 3 A flowchart illustrating another adaptive haptic feedback method for a touchscreen provided in this application embodiment. Based on the above embodiments, as... Figure 3 As shown, optionally, the adaptive haptic feedback method of the touchscreen includes:

[0111] S301. Obtain the pressure signals of each pressure detection point on the surface of the touch screen.

[0112] S302. The pressure signal is processed using the exponential moving average algorithm to obtain the contact pressure distribution dataset.

[0113] S303. Extract the outer rectangular boundary of the contact area from the contact pressure distribution dataset, and determine the compact contact area based on the aspect ratio of the outer rectangular boundary.

[0114] S304. The contact pressure distribution dataset of the compact contact area is divided into grids. A contact pressure distribution map is generated based on the pressure value of each grid cell. The peak point of the contact pressure distribution map is located, and the offset vector of the peak point relative to the geometric center of the compact contact area is calculated. The offset vector includes the offset distance and the offset direction.

[0115] S305. Establish a polar coordinate system with the peak point as the origin of the polar coordinate system and the direction of the offset vector as the direction of the polar coordinate axis; where the polar radius is the distance from the origin of the polar coordinate system to any pressure detection point in the compact contact area, and the polar angle is the angle between the offset vector and the ray pointing from the origin of the polar coordinate system to the pressure detection point.

[0116] Specifically, using the peak point as the origin of the coordinate system allows us to pinpoint the core of the pressure distribution, ensuring that subsequent analysis focuses on the actual point of force application. Using the direction of the offset vector as the polar coordinate direction ensures that the coordinate axes align with the mechanical direction of the touch. For example, when the thumb tilts and presses, the coordinate system tilts synchronously, improving rotational robustness during touch recognition. The polar radius quantifies the radial distance between the pressure detection point within the contact area and the core of force application (i.e., the peak point), providing a spatial scale for calculating the pressure attenuation gradient. The polar angle determines the angle of the pressure detection point.

[0117] S306. According to the preset polar angle interval, the compact contact area is divided into multiple sector analysis areas in the polar coordinate system, and then each sector analysis area is divided into multiple equally spaced rings according to the preset radial spacing.

[0118] For example, the contact area is first divided into 12 sector-shaped analysis zones at a preset angle (e.g., 30°) to capture the angular non-uniformity of pressure distribution; then, within each sector, equal-width rings are divided at radial intervals (e.g., 1 mm) to quantify the attenuation law of pressure with radius.

[0119] S307. Extract the pressure data sequence of the corresponding equally spaced rings in each sector analysis area, calculate the radial change rate of pressure in the equally spaced rings, and obtain the pressure attenuation gradient value.

[0120] Specifically, the radial rate of change of pressure refers to the rate at which the pressure value changes with increasing distance along the radial direction (i.e., the direction radiating outward from the peak point) within the same sector of analysis.

[0121] In this embodiment, the pressure attenuation gradient value can quantify the rate attenuation of pressure as it diffuses outward from its peak point. For example, the fingertip attenuates quickly with a large gradient, while the fingertip attenuates slowly with a small gradient. The pressure attenuation gradient value can be used to further accurately identify the contact area.

[0122] S308. Select a symmetrical sector analysis region with the line containing the offset vector as the axis of symmetry, calculate the cosine similarity of the pressure data sequences of the equally spaced rings in each layer of the symmetrical sector analysis region, and obtain the pressure mirror similarity.

[0123] Specifically, cosine similarity measures the similarity between two vectors in terms of direction. The range of cosine similarity is [-1, 1]. For example, a value of 1 indicates that the two vectors are in the same direction, i.e., positively correlated; a value of 0 indicates that the two vectors are orthogonal, i.e., uncorrelated; and a value of -1 indicates that the two vectors are in completely opposite directions, i.e., negatively correlated.

[0124] In this embodiment, pressure data sequences from equally spaced rings within the same layer of a symmetrical sector analysis region (e.g., 30°-60° and 300°-330° sectors) are taken. The cosine similarity between the two sectors is calculated for each ring, and the similarity value of a single ring is output. The pressure mirror similarity is obtained by taking the weighted average of the cosine similarities of each ring. For example, the pressure mirror similarity of the fingertip is higher than that of the fingertip.

[0125] S309. Determine the contact points of the compact contact area based on the offset distance, pressure attenuation gradient value, and pressure mirror similarity, and generate corresponding contact point labels.

[0126] Optionally, if the offset distance is less than or equal to the first preset offset distance, and the pressure attenuation gradient value is greater than or equal to the first preset attenuation gradient value, and the pressure mirror similarity is greater than or equal to the first preset mirror similarity, then the compact contact area is determined to be a fingertip contact, and a fingertip contact label is generated.

[0127] Specifically, the first preset offset distance refers to the maximum allowable offset distance for determining fingertip contact. For example, the first preset offset distance is 0.5 mm. The first preset attenuation gradient value refers to the pressure attenuation rate threshold for distinguishing between the fingertip and the fingertip. For example, the first preset attenuation gradient value can be 35 Pa / mm. The first preset mirror similarity refers to the minimum pressure symmetry required to determine fingertip contact. For example, the first preset mirror similarity is 0.9.

[0128] In this embodiment, fingertip contact exhibits high concentration and strong symmetry. Specifically, when a fingertip touches the screen perpendicularly, the pressure peak is close to the geometric center, resulting in a small offset distance. Simultaneously, due to the skeletal support of the fingertip, the pressure rapidly decreases from the center outwards, leading to a large pressure attenuation gradient. Furthermore, the pressure distribution at the fingertip is centrally symmetrical, resulting in high mirror similarity. Therefore, by setting three conditions—offset distance ≤ first preset offset distance, pressure attenuation gradient value ≥ first preset attenuation gradient value, and pressure mirror similarity ≥ first preset mirror similarity—accurate fingertip contact can be identified.

[0129] Optionally, if the first preset offset distance < offset distance ≤ second preset offset distance, and the second preset attenuation gradient value ≤ pressure attenuation gradient value < first preset attenuation gradient value, and the second preset mirror similarity ≤ pressure mirror similarity < first preset mirror similarity, then the compact contact area is determined to be fingertip contact, and a fingertip contact label is generated.

[0130] Specifically, the second preset mirror similarity refers to the lower limit of symmetry for distinguishing fingertip contact from atypical contact. For example, the second preset mirror similarity is 0.5. The second preset offset distance refers to the maximum allowable offset distance for determining fingertip contact. For example, the second preset offset distance is 3mm. The second preset attenuation gradient value refers to the minimum allowable threshold for pressure attenuation in fingertip contact. For example, the second preset attenuation gradient value is 25Pa / mm.

[0131] In this embodiment, fingertip contact exhibits elastic deformation characteristics, tolerating moderate offset and asymmetry. Specifically, soft tissue deformation of the fingertip causes the peak point to shift towards the force-bearing side, resulting in a larger offset distance compared to fingertip contact. Due to muscle cushioning in the fingertip, pressure decays slowly, leading to a relatively smaller pressure decay gradient value for fingertip contact. Furthermore, the fingertip structure is naturally asymmetrical, with radial pressure on the thumb being greater than ulnar pressure, resulting in a smaller pressure mirror similarity for fingertip contact compared to fingertip contact. Therefore, by setting three conditions—a first preset offset distance < offset distance ≤ second preset offset distance, a second preset decay gradient value ≤ pressure decay gradient value < first preset decay gradient value, and a second preset mirror similarity ≤ pressure mirror similarity < first preset mirror similarity—fingertip contact can be accurately identified.

[0132] Optionally, if the offset distance is greater than the second preset offset distance, or the pressure attenuation gradient value is less than the second preset attenuation gradient value, or the pressure mirror similarity is less than the second preset mirror similarity, then the compact contact area is determined to be an atypical contact, and an atypical contact label is generated.

[0133] Specifically, atypical contact refers to contact behaviors that do not conform to the mechanical characteristics of normal human touch areas (fingertips / finger pads). Examples of atypical contact include knuckle tapping, fingernail scratching, and contact with foreign objects. Identifying atypical contact helps eliminate unintentional actions and improves the user experience.

[0134] S310. Match the corresponding tactile feedback mode according to the label of the contact area.

[0135] Optionally, if a fingertip touches the tag, the tap vibration mode is activated. If a fingertip touches the tag, the rebound vibration mode is activated. If an atypical touch tag is detected, the no-feedback mode remains.

[0136] Specifically, the click vibration mode refers to a millisecond-level transient haptic feedback, simulating an instantaneous trigger sensation by generating a single-pulse high-acceleration vibration waveform. The rebound vibration mode refers to a gradually decaying haptic feedback, simulating the compression deformation and recovery process of an elastic material through a multi-order damped oscillation waveform. The no-feedback mode refers to a state where the touchscreen has no vibration and no pressure feedback.

[0137] In this embodiment of the application, by designing differentiated tactile features, the touch screen can establish corresponding feedback mechanisms based on different user contact areas, thereby improving the human-computer interaction experience.

[0138] The technical solution of this application, by establishing a polar coordinate system and dividing the analysis area into sectors, extracts pressure data, calculates pressure attenuation gradient values ​​and pressure mirror similarity, thus solving the problem of inaccurate identification of user contact points on touchscreens. Based on these indicators, it accurately distinguishes between fingertips, fingertips, and atypical contacts, generates corresponding contact point labels, and matches corresponding haptic feedback modes accordingly, thereby improving the user interaction experience and the accuracy of haptic feedback.

[0139] Figure 4 This is a schematic diagram of the structure of an adaptive haptic feedback system for a touchscreen provided in an embodiment of this application. Figure 4 As shown, the system includes:

[0140] The signal acquisition module 410 is used to acquire the pressure signal on the surface of the touch screen and filter the pressure signal to obtain a contact pressure distribution dataset.

[0141] The regional screening module 420 is used to extract the outer rectangular boundary of the contact area from the contact pressure distribution dataset and determine the compact contact area based on the aspect ratio of the outer rectangular boundary.

[0142] The offset vector acquisition module 430 is used to divide the contact pressure distribution dataset of the compact contact area into grids, generate a contact pressure distribution map based on the pressure value of each grid cell, locate the peak point of the contact pressure distribution map, and calculate the offset vector of the peak point relative to the geometric center of the compact contact area; wherein, the offset vector includes the offset distance and the offset direction.

[0143] The pressure analysis module 440 is used to establish a polar coordinate system based on the peak point and offset vector and divide the sector analysis area, extract the pressure data sequence of equally spaced rings within the sector analysis area, and obtain the pressure attenuation gradient value and pressure mirror similarity of the compact contact area based on the pressure data sequence.

[0144] The contact location determination module 450 is used to determine the contact locations of a compact contact area based on the offset distance, pressure attenuation gradient value, and pressure mirror similarity, and generate corresponding contact location labels.

[0145] The haptic feedback module 460 is used to match the corresponding haptic feedback mode according to the label of the contact area.

[0146] The adaptive haptic feedback system for touch screens provided in this application can execute the adaptive haptic feedback method for touch screens provided in any embodiment of this application, and has the corresponding functional modules and beneficial effects of executing the method.

[0147] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0148] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An adaptive haptic feedback method for a touchscreen, characterized in that, include: Acquire the pressure signal on the surface of the touch screen, and filter the pressure signal to obtain a contact pressure distribution dataset; Extract the outer rectangular boundary of the contact area from the contact pressure distribution dataset, and determine the compact contact area based on the aspect ratio of the outer rectangular boundary; The contact pressure distribution dataset of the compact contact area is divided into grids, and a contact pressure distribution map is generated based on the pressure value of each grid cell. The peak point of the contact pressure distribution map is located, and the offset vector of the peak point relative to the geometric center of the compact contact area is calculated. The offset vector includes an offset distance and an offset direction. A polar coordinate system is established based on the peak point and the offset vector, and a sector analysis area is divided. Pressure data sequences of equally spaced rings within the sector analysis area are extracted. The pressure attenuation gradient value and pressure mirror similarity of the compact contact area are obtained based on the pressure data sequences. The contact points of the compact contact area are determined based on the offset distance, the pressure attenuation gradient value, and the pressure mirror similarity, and corresponding contact point labels are generated. The corresponding tactile feedback mode is matched according to the label of the contact area.

2. The adaptive haptic feedback method for a touchscreen according to claim 1, characterized in that, The touchscreen surface is provided with multiple pressure detection points. The process of acquiring pressure signals from the touchscreen surface and filtering the pressure signals to obtain a contact pressure distribution dataset includes: Acquire the pressure signals at each pressure detection point on the surface of the touch screen; The pressure signal is processed using an exponential moving average algorithm to obtain the contact pressure distribution dataset.

3. The adaptive haptic feedback method for a touchscreen according to claim 2, characterized in that, The step of extracting the circumscribed rectangular boundary of the contact area from the contact pressure distribution dataset and determining the compact contact area based on the aspect ratio of the circumscribed rectangular boundary includes: Points in the contact pressure distribution dataset that are greater than a preset pressure value are identified as effective contact areas. Using the detection coordinate system of the touch screen as a reference, obtain the maximum value of the horizontal coordinate, the minimum value of the horizontal coordinate, the maximum value of the vertical coordinate, and the minimum value of the vertical coordinate of all pressure detection points in the effective contact area; Construct the smallest rectangle that encloses the effective contact area based on the maximum and minimum values ​​of the horizontal coordinate, the maximum and minimum values ​​of the vertical coordinate, and the smallest rectangle is the boundary of the circumscribed rectangle; The contact area whose aspect ratio of the circumscribed rectangle is within a preset aspect ratio range is defined as the compact contact area.

4. The adaptive haptic feedback method for a touchscreen according to claim 3, characterized in that, The process of dividing the contact pressure distribution dataset of the compact contact area into grids, generating a contact pressure distribution map based on the pressure value of each grid cell, locating the peak point of the contact pressure distribution map, and calculating the offset vector of the peak point relative to the geometric center of the compact contact area includes: The grid cells are divided according to the pixel resolution of the touchscreen; The pressure value within each grid cell is subjected to bilinear interpolation to generate a continuous contact pressure distribution map; By iterating through the pressure values ​​of all grid cells in the contact pressure distribution map, the target grid cell with the largest pressure value is selected, and the location with the largest pressure value in the target grid cell is the peak point. Based on the detection coordinate system, the coordinates of the peak point and the coordinates of the geometric center of the compact contact area are extracted respectively, and the offset distance and offset direction of the peak point relative to the geometric center of the compact contact area are calculated.

5. The adaptive haptic feedback method for a touchscreen according to claim 2, characterized in that, The process of establishing a polar coordinate system based on the peak point and the offset vector, dividing the analysis area into sector-shaped regions, extracting pressure data sequences of equally spaced rings within the sector-shaped analysis area, and obtaining the pressure attenuation gradient value and pressure mirror similarity of the compact contact region based on the pressure data sequences includes: A polar coordinate system is established with the peak point as the origin of polar coordinates and the direction of the offset vector as the polar coordinate axis direction; wherein, the polar radius is the distance from the origin of polar coordinates to any pressure detection point in the compact contact area, and the polar angle is the angle between the offset vector and the ray pointing from the origin of polar coordinates to the pressure detection point; According to the preset polar angle interval, the compact contact area is divided into multiple sector-shaped analysis areas in the polar coordinate system, and then each sector-shaped analysis area is divided into multiple equally spaced rings according to the preset radial spacing; Extract the pressure data sequence corresponding to the equally spaced rings within each of the sector analysis regions, calculate the radial rate of change of pressure in the equally spaced rings, and obtain the pressure attenuation gradient value; A symmetrical sector analysis region with the line containing the offset vector as the axis of symmetry is selected, and the cosine similarity of the pressure data sequence of the equally spaced rings in each layer of the symmetrical sector analysis region is calculated to obtain the pressure mirror similarity.

6. The adaptive haptic feedback method for a touchscreen according to claim 1, characterized in that, The step of determining the contact points of the compact contact region based on the offset distance, the pressure attenuation gradient value, and the pressure mirror similarity, and generating corresponding contact point labels, includes: If the offset distance is less than or equal to the first preset offset distance, and the pressure attenuation gradient value is greater than or equal to the first preset attenuation gradient value, and the pressure mirror similarity is greater than or equal to the first preset mirror similarity, then the compact contact area is determined to be a fingertip contact, and a fingertip contact label is generated.

7. The adaptive haptic feedback method for a touchscreen according to claim 6, characterized in that, The step of determining the contact points of the compact contact region based on the offset distance, the pressure attenuation gradient value, and the pressure mirror similarity, and generating corresponding contact point labels, further includes: If the first preset offset distance < the offset distance ≤ the second preset offset distance, and the second preset attenuation gradient value ≤ the pressure attenuation gradient value < the first preset attenuation gradient value, and the second preset mirror similarity ≤ the pressure mirror similarity < the first preset mirror similarity, then the compact contact area is determined to be fingertip contact, and a fingertip contact label is generated.

8. The adaptive haptic feedback method for a touchscreen according to claim 7, characterized in that, The step of determining the contact points of the compact contact region based on the offset distance, the pressure attenuation gradient value, and the pressure mirror similarity, and generating corresponding contact point labels, further includes: If the offset distance is greater than the second preset offset distance, or the pressure attenuation gradient value is less than the second preset attenuation gradient value, or the pressure mirror similarity is less than the second preset mirror similarity, then the compact contact area is determined to be an atypical contact, and an atypical contact label is generated.

9. The adaptive haptic feedback method for a touchscreen according to claim 8, characterized in that, The step of matching the corresponding tactile feedback mode based on the contact area label includes: If the fingertip touches the tag, the click vibration mode is activated; If the fingertip is detected to be in contact with the tag, the rebound vibration mode is activated; If the atypical contact tag is detected, the no-feedback mode is maintained.

10. An adaptive haptic feedback system for a touchscreen, characterized in that, include: The signal acquisition module is used to acquire the pressure signal on the surface of the touch screen and filter the pressure signal to obtain a contact pressure distribution dataset. The regional screening module is used to extract the outer rectangular boundary of the contact area from the contact pressure distribution dataset, and determine the compact contact area based on the aspect ratio of the outer rectangular boundary. The offset vector acquisition module is used to divide the contact pressure distribution dataset of the compact contact area into grids, generate a contact pressure distribution map based on the pressure value of each grid cell, locate the peak point of the contact pressure distribution map, and calculate the offset vector of the peak point relative to the geometric center of the compact contact area; wherein, the offset vector includes an offset distance and an offset direction; The pressure analysis module is used to establish a polar coordinate system and divide the sector analysis area based on the peak point and the offset vector, extract the pressure data sequence of equally spaced rings in the sector analysis area, and obtain the pressure attenuation gradient value and pressure mirror similarity of the compact contact area based on the pressure data sequence. The contact location determination module is used to determine the contact location of the compact contact area based on the offset distance, the pressure attenuation gradient value, and the pressure mirror similarity, and generate corresponding contact location labels. The tactile feedback module is used to match the corresponding tactile feedback mode according to the label of the contact area.

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