Method, device and system for generating local vibration tactile feedback and computing equipment

Abstract

The invention provides a method, a device and a system for generating local vibration tactile feedback and computing equipment. The method comprises the following steps: determining an intrinsic mode set and a reference mode participation coefficient set associated with a vibration plate based on a target vibration position and a reference vibration field at the target vibration position; determining a target vibration field at the target vibration position based on the intrinsic mode set and the reference mode participation coefficient set; selecting an intrinsic mode subset for mode superposition and a mode participation coefficient subset corresponding to the intrinsic mode subset based on the reference mode participation coefficient set, wherein a superposition vibration field generated based on the intrinsic mode subset and the mode participation coefficient subset corresponding to the intrinsic mode subset and a target vibration field meet a preset similarity requirement; and based on the intrinsic mode subset, the corresponding mode participation coefficient subset and the position of the vibration assembly, determining driving control information for driving the vibration assembly to generate local vibration tactile feedback at the target vibration position.

Description

Method, apparatus, system, and computing device for generating localized vibrotactile feedback Technical Field

[0001] The present application relates to the field of touch technology, and more particularly, to a method, apparatus, system, and computing device for generating localized vibrotactile feedback at a target vibration position on a vibrating plate. Background Art

[0002] Haptic feedback is an essential channel for achieving immersive interaction. Beyond audio-visual interaction, virtual touch can be integrated into various interactive media, such as mobile phones, tablets, and in-vehicle displays, significantly enhancing the human-computer interaction experience. Haptic feedback is fundamental to numerous applications, including human-computer interface design, assistance for the blind, and gaming and entertainment. In recent years, haptic feedback technology, traditionally used for basic functions like vibration reminders and press confirmation, has evolved toward achieving more complex and refined tactile feedback effects, primarily including localized vibration and texture pattern reproduction.

[0003] Traditional vibrotactile feedback only achieves overall vibration, and is unable to achieve localized vibrotactile feedback over a smaller area, thus preventing the creation of more complex and sophisticated tactile feedback effects. Furthermore, when achieving localized vibrotactile feedback effects based on high-frequency vibration or electrostatic friction, it can be difficult to easily control the frequency within the range to which the human sense of touch is most sensitive (e.g., 50-500Hz).

[0004] Therefore, there is a need for a device that can simultaneously achieve local vibration tactile feedback and has a vibration frequency within the frequency range to which the human body is most sensitive (for example, 50-500 Hz).

[0005] Summary of the Invention

[0006] According to one aspect of the present application, a method for generating localized vibrotactile feedback at a target vibration position on a vibration plate is provided, comprising: determining a reference modal participation coefficient set corresponding to an eigenmode set associated with the vibration plate based on the target vibration position and a reference vibration field at the target vibration position; determining a target vibration field at the target vibration position based on the eigenmode set and the reference modal participation coefficient set; selecting an eigenmode subset for modal superposition from the eigenmode set, and determining a modal participation coefficient subset corresponding to the eigenmode subset, wherein a superimposed vibration field generated based on the eigenmode subset and its corresponding modal participation coefficient subset meets a preset similarity requirement with the target vibration field; and determining drive control information based on the eigenmode subset and its corresponding modal participation coefficient subset and a position of a vibration component at the vibration plate, wherein the drive control information is used to drive the vibration component to generate the localized vibrotactile feedback at the target vibration position.

[0007] According to another aspect of the present application, an apparatus for generating localized vibrotactile feedback at a target vibration position on a vibration plate is provided, comprising: a determination module for determining, based on the target vibration position and a reference vibration field at the target vibration position, a reference modal participation coefficient set corresponding to an eigenmode set associated with the vibration plate, and determining, based on the eigenmode set and the reference modal participation coefficient set, a target vibration field at the target vibration position; a selection module for selecting, from the eigenmode set, an eigenmode subset for modal superposition, and determining a modal participation coefficient subset corresponding to the eigenmode subset, wherein a superimposed vibration field generated based on the eigenmode subset and its corresponding modal participation coefficient subset meets a preset similarity requirement with the target vibration field; and a drive control module for determining drive control information based on the eigenmode subset and its corresponding modal participation coefficient subset and a position of a vibration component at the vibration plate, wherein the drive control information is used to drive the vibration component to generate the localized vibrotactile feedback at the target vibration position.

[0008] According to another aspect of the present application, a computing device is provided, comprising: a processor; and a memory on which a computer program is stored. When the computer program is executed by the processor, the method for generating localized vibration tactile feedback at a target vibration position on a vibration plate as described above is executed.

[0009] According to another aspect of the present application, a system for generating localized vibrotactile feedback at a target vibration position on a vibrating plate is provided, comprising: a vibrating plate provided with a plurality of vibrating components; a laser vibrometer for measuring an eigenmode set associated with the vibrating plate; a processing device for acquiring a reference vibration field at the target vibration position and the eigenmode set obtained by the laser vibrometer, and executing the method for generating localized vibrotactile feedback at the target vibration position on the vibrating plate as described above; and a driving circuit for generating and outputting a driving signal based on driving control information from the processing device to drive the plurality of vibrating components, so that the plurality of vibrating components drive the vibrating plate to vibrate.

[0010] Through the examples of this application, a smaller number of eigenmodes are selected for superposition by comparing the similarity between vibration fields to achieve a localized vibration tactile feedback effect, thereby reducing the corresponding circuit and hardware complexity and the amount of algorithm calculation, and facilitating the realization of complex (for example, multi-point local vibration) and high-resolution (area as small as 3cm) tactile feedback effects. In addition, by appropriately selecting the hardware configuration of the vibration plate, envelope wave modulation can also be achieved, so that the vibration frequency is within the frequency range that the human body is most sensitive to (for example, 50-500Hz), further improving the vibration effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings illustrate various embodiments of various aspects of the present application, and together with the description, they are used to explain the principles of the present application. Those skilled in the art will appreciate that the specific embodiments shown in the accompanying drawings are merely exemplary and are not intended to limit the scope of the present invention. In the accompanying drawings:

[0012] FIG1 shows a schematic diagram of a system for generating localized vibrotactile feedback at a target vibration position on a vibration plate according to an embodiment of the present application.

[0013] FIG2 is a schematic flow chart of a method for generating localized vibrotactile feedback at a target vibration position on a vibration plate according to an embodiment of the present application.

[0014] FIG3 shows a flowchart of the process of selecting the eigenmode subset in step S230 in FIG2 .

[0015] FIG4 shows an algorithm flow chart of the process of selecting the eigenmode subset in step S230 in FIG2 .

[0016] FIG5 is a schematic diagram showing the frequency response obtained during the laser vibrometer measurement process.

[0017] FIG6 shows a table illustrating the 42 eigenmodes identified by the laser vibrometric process.

[0018] FIG7( a ) shows the designed local vibrotactile feedback effect as a target.

[0019] FIG7( b ) shows the measured effect of local vibration tactile feedback obtained through the laser vibrometer process.

[0020] Figure 7(c) and Figure 7(d) show the vibration displacement distribution along the x-direction and y-direction, respectively.

[0021] FIG8(a)-FIG8(d) further illustrate the velocity information of the vibration field at the target vibration position in FIG7(a)-FIG7(d).

[0022] FIG9( a ) shows the designed two-point local vibrotactile feedback effect as the target.

[0023] FIG9( b )-FIG 9( c ) show the measured effects of two-point local vibration tactile feedback obtained through the laser vibrometer process.

[0024] FIG10( a ) to FIG10 ( f ) show the 5-point local vibrotactile feedback effects obtained by the laser vibrometry process, where only about 10 eigenmodes are used.

[0025] FIG11 shows a structural block diagram of an apparatus for generating localized vibrotactile feedback at a target vibration position on a vibration plate according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0027] The present disclosure is mainly used to generate local vibration tactile feedback at one or more target vibration positions on a vibration plate. In order to better describe the present disclosure, the vibration generation principle at various positions of the vibration plate is first briefly introduced.

[0028] For a uniform, isotropic, homogeneous thin plate (i.e., a vibrating plate), deformation occurs primarily in the direction perpendicular to the plane, which can be used to achieve tactile feedback. According to Kirchhoff's plate theory, the dynamic equation for a rectangular plate in free vibration can be expressed as:

[0029] in is the bending stiffness, ρ is the density of the plate, h t is the thickness, E is the elastic modulus, and ν is the Poisson's ratio. is the Laplace operator, and w(x,y,t) represents the vibration field corresponding to the position (x,y) where the vibration occurs and the time t. The solution of Equation (1) can be written in the form of variable separation:

[0030] in, is the bending mode of the rectangular plate at position (x, y), φ is the initial phase, ω is the angular frequency, then the vibration mode equation of the bending mode can be expressed as

[0031] The solution of Equation (3) is the eigenmodes (also called mode shapes) of a series of eigenmodes of the rectangular plate. n is the nth mode, which depends on the boundary conditions. Each mode has a specific natural frequency, damping ratio and mode shape. Usually, the natural angular frequency ω of the nth mode is n It can be expressed as

[0032] The resonant frequency f can also be obtained from the natural angular frequency n ,λ ij It only depends on the order of the nth eigenmode, the aspect ratio a / b of the vibrating plate, and the boundary conditions. If the mode shape is normalized according to the vibrating mass, the mode shape satisfies the orthogonality:

[0033] where δ kl is the Kronecker symbol, represents the normalized mode k. Due to the orthogonality and infinite number of bending modes, the mode shape Constitute a complete set of bases. That is, any periodic vibration can be expressed by modal decomposition as

[0034] There are infinite modes, η n is the modal participation coefficient of the nth eigenmode (weight, the contribution of this mode to the local vibration tactile feedback effect to be generated), is the nth eigenmode vibration shape, φ n is the initial phase of the nth eigenmode. Based on the orthogonality and integrity of the eigenmode vibration shapes, any artificially designed local vibration effect can be constructed, that is, the desired vibration field at the position (x, y) that changes with time t. The superimposed vibration field of an infinite number of modes can also be expressed in complex form as:

[0035] in The complex form of the modal participation coefficient facilitates the related solutions in the following steps. However, in practical applications, the number of available modes is limited because higher-order modes are difficult to measure and excite in experiments (i.e., higher-order modes cannot be easily obtained). Therefore, assuming that the first N modes are available, the superimposed vibration field w(x, y, t) of the N modes can be expressed using truncated modes as follows:

[0036] It can be seen from the above introduction that local vibration tactile feedback can be achieved based on modal superposition.

[0037] Fig. 1 shows a schematic diagram of a system for generating localized vibrotactile feedback at target vibration positions on a vibration plate according to an embodiment of the present application. Optionally, the number of target vibration positions can be one or more.

[0038] The system 100 may include a vibration plate 110 , a laser vibrometer 120 , a processing device 130 , and a driving circuit 140 .

[0039] The vibration plate 110 can be provided with multiple vibration components (e.g., multiple piezoelectric plates arranged on the edges of the vibration plate), each vibrating in response to a corresponding drive signal, thereby generating localized vibrotactile feedback at a target vibration location on the vibration plate. The vibration plate 110 can be a carrier for various types of integrated tactile feedback, such as a glass plate, display screen, touchpad, smart surface, etc., to enhance the human-computer interaction experience, as shown in Figure 1.

[0040] The laser vibrometer 120 (e.g., including a laser Doppler vibrometer and its corresponding vibrometer controller) is used to measure the eigenmode set of the vibrating plate and various vibrations on the vibrating plate. For example, the vibrometer controller can obtain a vibrometer reference signal for use in the laser vibrometer process. For a uniform, isotropic, and homogeneous thin plate, deformation primarily occurs in the direction perpendicular to the plane, which can be used to achieve tactile feedback. In addition, for a vibrating plate of any material and properties, there are corresponding multiple eigenmodes. These eigenmodes are inherent and related to the inherent hardware configuration of the vibrating plate. Once one or more of these eigenmodes are excited, tactile feedback can be achieved on the vibrating plate 110 by superposition of the excited eigenmodes. Therefore, after determining the material, dimensions, and various other hardware parameters of the vibrating panel, the laser vibrometer 120 can be used to measure the eigenmode set of the vibrating plate (e.g., based on the frequency response and using a peak determination method (i.e., there is an eigenmode at each peak)). After the eigenmode set is identified, it can be stored as a complex matrix (including information such as the amplitude or phase of each mode), for example locally or in a storage device independent of the laser vibrometer device.

[0041] The processing device 130 is used to obtain the set of eigenmodes measured by the laser vibrometer and generate drive control information based on the target vibration position where local vibration tactile feedback is desired and its reference vibration field (in the actual processing process, for the convenience of calculation, the reference vibration field of the target vibration position can be set to 1, that is, the amplitude at a certain time (for example, t=0) at the target vibration position is set to 1), so as to control the drive circuit to generate a drive signal for driving multiple vibration components, thereby generating local vibration tactile feedback at the target vibration position. The process of how the processing device generates drive control information will be described in detail later. The processing device 130 can be any device with processing functions and can be implemented by a combination of hardware and software. For example, the processing device can include a memory and a processor, so that the processor can execute a computer program stored on the memory.

[0042] The driving circuit 140 is configured to generate and output a driving signal based on the driving control information from the processing device to drive the plurality of vibration components, so that the plurality of vibration components drive the vibration plate to vibrate.

[0043] Optionally, the drive circuit may include a waveform generating circuit and a voltage amplifying circuit. The waveform generating circuit generates a multi-channel voltage signal for multiple channels (corresponding to multiple vibration components) having a waveform indicated by the drive control information based on the drive control information. The waveform generating circuit may be multi-channel, and the voltage amplifying circuit may also be multi-channel, that is, each channel may include a waveform generating circuit and a voltage amplifying circuit, so that the voltage amplifying circuit of each channel can be used to amplify the voltage signal generated by the waveform generating signal of the corresponding channel to generate a drive signal for driving the multiple vibration components respectively.

[0044] Each channel can output a voltage signal with any excitation waveform. The number of channels can be the same as the number of vibrating components, enabling one-to-one driving of each vibrating component. The drive control information (voltage information) calculated by processing device 130, including information for driving the vibrating component, is converted by the drive circuit into an actual voltage signal, which drives (excites) the corresponding vibrating component (e.g., a piezoelectric element) to vibrate. Optionally, the waveform generation circuit also provides a reference signal for laser vibrometry when scanning the vibration field.

[0045] It should be understood that FIG1 merely illustrates several components within the system 100 and does not limit the components included in the system. In actual practice, the system may include more components. For example, the system 100 may also include a power module (e.g., a battery or a voltage converter, etc.) to provide power to, for example, the processing device and the drive circuit within the system.

[0046] Fig. 2 is a flow chart showing a method for generating localized vibrotactile feedback at a target vibration position on a vibrating plate according to an embodiment of the present application. The method shown in Fig. 2 can be executed by the controller in Fig. 1 .

[0047] As shown in FIG. 2 , in step S210 , a reference modal participation coefficient set corresponding to the eigenmode set associated with the vibrating plate is determined based on a target vibration position and a reference vibration field at the target vibration position.

[0048] Optionally, the number of target vibration positions may be one or more, i.e., it is expected that corresponding local vibrotactile feedback can be achieved at these target vibration positions (represented by multiple sets of coordinates (x, y)) through the superposition of these eigenmodes. The reference vibration field can be used to represent the local vibrotactile feedback desired to be achieved at the target vibration positions, and in the case of multiple target vibration positions, there are corresponding multiple reference vibration fields.

[0049] For example, the position space grid on the vibration plate can be divided into multiple local vibration areas arranged in S rows and T columns, and one or more discrete positions may be set within each local vibration area. Generally, in order to maximize the resolution (reduce the area of ​​the local vibration area, so that the total number of discrete positions is larger), the area of ​​each local vibration area can be reduced, and only one position element in the area is set to 1, that is, only one discrete position is set in each local vibration area of ​​the vibration plate, that is, it is represented by only one corresponding coordinate (x, y). The reference vibration field matrix can be used to represent the reference vibration field at the preset number of discrete positions. For example, the 0 and 1 values ​​at each position of the reference vibration field matrix arranged in S rows and T columns corresponding to the area matrix arranged in S rows and T columns can indicate whether vibration is expected to be generated at the corresponding discrete position on the vibration plate. The value of the element corresponding to the target vibration position in the reference vibration field matrix is ​​set to 1, and the elements corresponding to the remaining positions are set to 0. Of course, the reference vibration field may also be set in other ways. For example, the element corresponding to one target vibration position in the reference vibration field matrix may be set to 1, and the element corresponding to another target vibration position may be set to 2, so that the amplitudes of the vibrations at the two target vibration positions are approximately twice as great at the same time.

[0050] Optionally, in the process of determining the reference modal participation coefficient based on the reference vibration field, for each discrete position among a preset number of discrete positions on the vibration plate, the vibration field representation at the discrete position can be determined based on the measured modal vibration shape of each eigenmode at the discrete position and the unknown modal participation coefficient corresponding to each eigenmode; and the value of the modal participation coefficient corresponding to each eigenmode is adjusted, and the value of the modal participation coefficient corresponding to each eigenmode when the sum of the differences between the vibration field representation at each discrete position and the corresponding reference vibration field is minimized is used as the reference modal participation coefficient corresponding to each eigenmode in the eigenmode set.

[0051] For example, it can be assumed that the reference vibration field w at the target vibration position (x, y) is r (x, y) is obtained at t = 0. Of course, depending on the vibration field representation, the reference vibration field can also be obtained at other appropriate times or frequencies. Furthermore, unlike the theoretical assumption that each discrete location on the vibrating plate vibrates in either the same direction (phase 0°) or opposite direction (phase 180°), the actual phase field at each discrete location is not binary but rather ranges from [-10°, 10°] or [170°, 190°], thus being described using a complex matrix.

[0052] Therefore, the reference vibration field can be expressed in complex form as follows in combination with the above formula (8).

[0053] In addition, the coordinates (x, y) of the target vibration position can be rewritten in discrete form based on the position space grid (S rows and T columns) when the eigenmode is measured. Therefore, formula (9) can be expressed as:

[0054] Where M is the number of discrete locations, N is the number of eigenmodes in the measured eigenmode set, and w m r =w r (x m ,y m )(where m=1, 2, ..., M) is the reference vibration field at the mth discrete position. If local vibration tactile feedback is not desired at a certain discrete position, the corresponding reference vibration field is 0, otherwise it is 1. is the vibration shape of the nth eigenmode at the mth discrete position. n r is the modal participation coefficient corresponding to the nth eigenmode. For example, the vibration field at discrete position 1 can be represented as The vibration field at discrete position 2 can be expressed as etc.

[0055] Formula (10) is a linear equation system. In general, the number of discrete positions M is much larger than the number of eigenmodes N that can be measured, so Formula (10) is an overdetermined equation system. In this case, a n r The equation group (10) cannot be strictly satisfied. In order to obtain the weight participation coefficient corresponding to each eigenmode, which can be used to generate local vibrotactile feedback at the target vibration position, the problem becomes finding the most suitable a n r That is to say, the superimposed vibration field actually obtained by superimposing these eigenmodes cannot be completely consistent with the artificially set reference vibration field, but the modal participation coefficient corresponding to each eigenmode can be determined so that the difference between the superimposed vibration field and the reference vibration field is as small as possible.

[0056] For example, when the preset number M of the discrete positions is greater than the first number N of eigenmodes in the eigenmode set, an overdetermined set of equations is constructed based on the vibration field representation at each discrete position (m) and the corresponding reference vibration field, wherein the first number of unknown modal participation coefficients in the vibration field representation at each discrete position is used as equation variables; then, the overdetermined set of equations is solved using a least squares method to obtain the value of the reference modal participation coefficient corresponding to each eigenmode that minimizes the sum of the differences between the vibration field representation at each discrete position and the corresponding reference vibration field.

[0057] For example, it can be determined in the following way.

[0058] The matrix formula (10) can be abbreviated as W r =ΦA, formula (11)

[0059] Where Φ is an M×N matrix, and M>N. Use the pseudo-inverse method to solve Equation (11). The matrix Φ can be expressed by singular value decomposition as Φ=UΣV T , formula (12)

[0060] Where U is an M×M orthogonal matrix, V is an N×N orthogonal matrix, and Σ is an M×N diagonal matrix. Then is an N×M diagonal matrix that satisfies

[0061] Then the pseudo-inverse of the matrix Φ It can be expressed as

[0062] The modal participation coefficient can be expressed as

[0063] Therefore, the overdetermined equation can be solved by the least squares method to obtain the optimal solution of A:

[0064] In step S220 , a target vibration field at a target vibration position is determined based on the set of eigenmodes and the set of reference modal participation coefficients.

[0065] In theory, the modal participation coefficient corresponding to each eigenmode is determined by the reference vibration field, as shown in formula (16). However, due to the truncation of the eigenmode (i.e., the removal of high-order eigenmodes that cannot be measured), the superimposed vibration field actually obtained at each target vibration position is not completely identical to the artificially set reference vibration field.

[0066] For example, by superimposing all N eigenmodes and the corresponding reference modal participation coefficients obtained in step S210, and then combining the position coordinates of the target vibration position, the target vibration field at the target vibration position can be obtained. The target vibration field will be used for subsequent comparison with the superimposed vibration field obtained by superimposing a smaller number of eigenmodes. Since it is desirable to use as few eigenmodes as possible but to be similar to the vibration field obtained by superimposing all eigenmodes (N), the vibration field obtained by superimposing all eigenmodes (N) is referred to as the target vibration field. The target vibration field w at the target vibration position (x, y) is t It can be expressed as follows:

[0067] In step S230, an eigenmode subset for modal superposition is selected from the eigenmode set, and a modal participation coefficient subset corresponding to the eigenmode subset is determined, wherein a superimposed vibration field generated based on the eigenmode subset and its corresponding modal participation coefficient subset meets a preset similarity requirement with the target vibration field.

[0068] In some cases, the second number N2 of eigenmodes in the selected eigenmode subset is equal to the first number N of eigenmodes in the eigenmode set, i.e., all eigenmodes in the eigenmode set (such as the N eigenmodes described above) are used for modal superposition. In this case, the modal participation coefficient corresponding to each eigenmode in the eigenmode subset is the same as the reference modal participation coefficient, and since all eigenmodes are superimposed, this is already the best achievable superposition result. Therefore, the generated superimposed vibration field (target vibration field) is necessarily sufficiently similar to the reference vibration field, and thus can be used as a target to be achieved in the subsequent sections of this document (as one of the similarity comparisons in the iterative process).

[0069] In other cases, considering that the more eigenmodes are selected, the more vibration components on the vibration plate will be, and the corresponding circuit complexity (such as the number of channels) and the amount of algorithm calculation will increase, only some of the eigenmodes can be selected from the eigenmode set for superposition, as long as the required local vibration tactile feedback can be achieved at the target vibration position. In addition, since the original modal participation coefficient is determined based on the reference vibration field for all eigenmodes, when a smaller number of eigenmodes are actually used, it is necessary to redetermine the corresponding modal participation coefficient based on the reference vibration field and for the smaller number of eigenmodes (such as Formula 16). At this time, the redetermined modal participation coefficient is different from the reference modal participation coefficient corresponding to the eigenmode. The generated superimposed vibration field and the target vibration field also need to meet the similarity requirements in order to produce the required local vibration tactile feedback at the target vibration position.

[0070] It should be noted that, in theory, the superimposed vibration field should be compared with the reference vibration field. However, since the reference vibration field is a value at time t=0 as described above, the superimposed vibration field is a signal that changes with time. Therefore, it is theoretically feasible to compare its value at t=0 with the reference vibration field (e.g., 1) to determine similarity. However, in order to better compare dynamic characteristics or local vibration patterns, the superimposed vibration field can be compared with the target vibration field to determine whether the selected eigenmode subset can be used to generate local vibration tactile feedback at the target vibration position.

[0071] Furthermore, to compare the superimposed vibration field with the target vibration field, embodiments of the present application propose an algorithm based on the Structural Similarity Index (SSIM). This SSIM measures the similarity between two superimposed vibration fields with different numbers of eigenmodes. Therefore, the similarity between a superimposed vibration field and a corresponding target vibration field (which is sufficiently similar to the reference vibration field) can be used to approximately reflect the similarity between the superimposed vibration field and the reference vibration field.

[0072] This application uses SSIM to evaluate the similarity between two local vibration modes (i.e., two vibration fields). Assume that w 1 (x,y) and w 2 (x, y) is the vibration field of two groups of different modal numbers superimposed, and the calculation formula of SSIM is:

[0073] Where μ1 and μ2 are the vibration fields w 1 and w 2 The average value of the vibration displacement distribution, σ1 and σ2 are w 1 and w 2 Standard deviation of the vibration displacement, σ 12 It is w 1 and w2 The covariance of the vibration field is , C1 and C2 are two constants. This index mainly considers three key features of the vibration mode and is expressed as: average vibration displacement, standard deviation of vibration displacement (contrast) and similarity of vibration field structure (structure). SSIM adopts and By measuring the three key features mentioned above separately and multiplying their results, SSIM enables quantitative evaluation of the similarity between local vibration modes, thereby preserving the target local vibration region.

[0074] How to select the eigenmode subset for superposition based on similarity will be described in detail later.

[0075] In step S240, drive control information is determined based on the eigenmode subset and its corresponding modal participation coefficient subset and the position of the vibration component at the vibration plate, wherein the drive control information is used to drive the vibration component to generate the local vibration tactile feedback at the target vibration position.

[0076] As described with reference to the system of FIG1 , the vibration component vibrates based on the drive signal (or the signal after high-voltage amplification), thereby driving the vibration plate to vibrate. For different selected subsets of eigenmodes, the combination of drive signals applied to each vibration component is different. For example, when the selected eigenmodes are Mode 1 and Mode 2, the drive signals required to be applied to each vibration component are different from the drive signals required to be applied to each vibration component when the selected eigenmodes are Mode 1, Mode 2, and Mode 3.

[0077] Therefore, it is necessary to determine the driving signal to be applied to each vibration component i based on the selected eigenmode subset (assuming that the number of eigenmodes is P) and the corresponding modal participation coefficient, for example:

[0078] Among them, Ui is the excitation voltage of the driving signal of the i-th vibration component, U am is the voltage amplitude that can be provided to each vibration component (for example, provided by the power module in FIG1 ). (x i ,y i ) is the position of the i-th vibration component, based on which the modal vibration shapes at the position of the i-th vibration component can be obtained Phase condition. a n r is the modal participation coefficient corresponding to each of the P eigenmodes (calculated based on the target vibration position, its reference vibration field, and the selected P eigenmodes).

[0079] After determining the drive signals that need to be applied to each vibration component i, the relevant information of these drive signals (i.e., drive control information) can be provided to a drive circuit capable of generating drive signals (for example, the drive circuit shown in Figure 1), so that the drive circuit can generate and output drive signals according to the drive control information.

[0080] The vibration component can realize local vibration tactile feedback at the target vibration position under the drive or excitation of the corresponding voltage driving signal.

[0081] By referring to the method for generating local vibration tactile feedback at a target vibration position on a vibration plate described with reference to FIG2 , a local vibration tactile feedback effect sufficiently similar to the desired local vibration tactile feedback effect can be achieved by superimposing multiple modes, and the number of selected modes can be smaller than the number of modes in the eigenmode set, thereby reducing the corresponding circuit complexity (such as the number of channels) and the amount of algorithm calculation.

[0082] Optionally, when a large number of eigenmodes are used for superposition, the resonant frequency f associated with each eigenmode is n The natural angular frequency ω can be expressed by formula (4) n It can be obtained from formula (4) that the resonant frequency f of each eigenmode is n Because it depends on the boundary conditions, the aspect ratio of the plate, and the order, the superimposed vibration field generated by superimposing multiple eigenmodes may include high-frequency vibration components and low-frequency vibration components. As a result, some high-frequency vibration components may not be within the frequency range that can be perceived by the human body (for example, 50 Hz to 500 Hz).

[0083] Superimposed vibration field (as shown in formula (17)) w t The envelope of is expressed as:

[0084] The first term of formula (20) is constant in time. The second term causes the envelope wave of the difference between the two resonant frequencies to change. In order to produce strong vibrotactile feedback, according to formula (4), the resonant frequency depends on the boundary conditions of the vibrating plate, the plate aspect ratio, and the order. Therefore, when selecting the hardware configuration of the vibrating plate, the above hardware parameters can be optimized so that the resonant frequency difference satisfies the formula f min <f i+1 -f i <f max Formula (21)

[0085] where f i is the resonant frequency of the ith eigenmode, f min and f max Set to 50Hz and 300Hz respectively.

[0086] In this way, the possible high-frequency vibration components in the superimposed vibration field can be modulated into low-frequency envelope waves, enabling better perception. Since the high-frequency vibration components have shorter wavelengths, this characteristic is maintained, resulting in a tactile feedback effect with higher resolution (smaller area). In other words, even when all eigenmodes are superimposed, the superimposed vibration field is still an improvement over existing solutions because it is better perceived.

[0087] The process of selecting the eigenmode subset in step S230 in FIG. 2 is described in detail below with reference to FIG. 3 and FIG. 4 .

[0088] As mentioned above, in some cases, all measured eigenmodes can be used for superposition and accordingly modulated based on the envelope wave, so that the superimposed vibration field at the target vibration position can be as similar as possible to the reference vibration field, and a better tactile feedback effect can also be achieved.

[0089] In addition, in other cases, the number of selected eigenmodes can be less than the total number of eigenmodes in the eigenmode set, thereby reducing the corresponding circuit complexity (such as the number of channels) and the amount of algorithm computation. The following describes the process of selecting eigenmodes in this case.

[0090] As previously described, calculating all eigenmodes based on the target vibration field and the reference modal participation coefficients based thereon is the optimal solution that can be obtained. Therefore, the target vibration field can be used as the target to be achieved by the superimposed vibration field obtained by superimposing fewer eigenmodes. In addition, the number of target vibration positions can also be one or more. Therefore, candidate eigenmodes for modal superposition can be selected from the eigenmode set in increasing numbers in different iteration rounds as eigenmode candidate subsets until one or more superimposed vibration fields at the one or more target vibration positions determined based on the eigenmode candidate subset selected in the latest iteration round and its corresponding modal participation coefficient subset meet the similarity threshold condition with the corresponding target vibration field. In this application, the similarity threshold condition can correspond to a threshold value, and satisfying this condition can be greater than or less than the threshold value, etc., depending on different condition setting methods. Similarly, the modal participation coefficient threshold condition below can also be interpreted in this way, and this application does not impose any restrictions on this. Whether the preset similarity requirement is met depends on whether the corresponding superimposed vibration field and the target vibration field meet the similarity threshold condition.

[0091] For example, when there is only one target vibration position, the situation is relatively simple, that is, there is only a comparison and iteration of the superimposed vibration field and the target vibration field at the target vibration position. When there are multiple target vibration positions, there are correspondingly multiple reference vibration fields that are not zero. As mentioned above, when determining the reference modal participation coefficient set, it is also based on the reference vibration fields of each discrete position (including these target vibration positions) (as shown in formulas (10) and (15)). Then, the target vibration field at each target vibration position can be determined based on the eigenmode set and the reference modal participation coefficient set and each target vibration position. In addition, it can be determined whether the superimposed vibration field obtained by superimposing the currently selected eigenmode candidate subset and its corresponding modal participation coefficient at each target vibration position and its corresponding target vibration field meet the similarity threshold condition, and the iteration is stopped only when the superimposed vibration field obtained by superimposing the target vibration field at each target vibration position and its corresponding target vibration field both meet the similarity threshold condition.

[0092] As described above, the similarity between two vibration fields (corresponding to different eigenmode subsets) may be determined based on a structural similarity index, so the similarity threshold condition here may correspond to a structural similarity threshold.

[0093] For example, one or more reference vibration fields w r The reference modal participation coefficient set a corresponding to all eigenmodes calculated (corresponding to one or more target vibration positions) n 0 (n is an integer between 1 and the number of all eigenmodes N) form a sequence, for example, they can be numbered as

[0094] Then, set an initial threshold a threshold 0 , for subsequent selection of eigenmodes, that is, starting from the first iteration process, the eigenmodes with modal participation coefficients greater than the initial threshold can be used for superposition, and the threshold can be updated according to the effect of the superposition vibration field generated by the selected eigenmode, so that it can be used for the next iteration when the next iteration is needed. In addition, the similarity threshold S can also be set threshold That is, if the similarity between the superimposed vibration field obtained based on the current eigenmode and the target vibration field is greater than or equal to the similarity threshold (or the superimposed vibration field at each target vibration position or the corresponding reference vibration field is greater than or equal to the similarity threshold), the iteration can be stopped.

[0095] The target vibration field at the position (x, y) (i.e., the target vibration field) is expressed as follows as described above:

[0096] Optionally, in general, the initial threshold a threshold 0 Will be set to [0.3, 0.5]*max{a n 0}, and the similarity threshold S threshold The threshold is set based on the tolerance of the local vibration pattern corresponding to the generated superimposed vibration field (which can also be obtained using a laser vibrometer). It is generally set between 0.2 and 0.6, and can be adjusted based on the tolerance for vibration amplitudes outside the desired target vibration location (local vibration location). Generally, within this range, vibrations outside the target local vibration area are observed to be suppressed to a level smaller than those within that area. When the vibration field is more complex, the similarity threshold can be relaxed appropriately.

[0097] The process of selecting the eigenmode candidate subset in each iteration round may include the following operations.

[0098] For example, as shown in FIG3 , in operation S230-1, based on the reference modal participation coefficient set and the current modal participation coefficient threshold condition, an eigenmode candidate subset for the current iteration round is selected from the eigenmode set, and a current modal participation coefficient subset corresponding to the eigenmode candidate subset for the current iteration round is determined.

[0099] Therefore, in the first iteration, the initial threshold a threshold 0 Generally, it is set to be large, so that only the participation coefficients a of all reference modes can be obtained. n 0 A smaller number of modal participation coefficients greater than the initial threshold are selected, that is, only a smaller number of eigenmodes can be selected as the eigenmode candidate subset for the current first iteration round. At this time, since the selected eigenmode candidate subset needs to be superimposed to maximize the realization of the reference vibration field (or target vibration field) at one or more target vibration positions, it is necessary to re-determine the modal participation coefficient corresponding to the eigenmode candidate subset based on the reference vibration field (e.g., reference vibration field matrix) at one or more target vibration positions as the current modal participation coefficient subset. In addition, if it is determined that further iterations are required based on subsequent operations, the threshold for the modal participation coefficient will be updated for other iteration rounds, for example, lowered, so that the reference modal participation coefficient a can be obtained. n 0 More modal participation coefficients greater than the initial threshold are selected than in the first iteration round, thereby selecting more eigenmodes and recalculating the corresponding modal participation coefficients.

[0100] That is, for the pth iteration round, based on the current athreshold p-1 (may be the initial threshold or the threshold of the previous update), from the reference modal participation coefficient set a n 0 Select a greater than the current threshold p-1 The modal participation coefficient of:

[0101] Make and Formula (23)

[0102] in is the sequence number of the eigenmode selected from the eigenmode set (the eigenmode candidate subset for the current iteration) for calculation in the p-th iteration, τ = 1, 2, ..., N p is the sequence number in the eigenmode candidate subset selected in the pth iteration. For example, the eigenmode candidate subset of the current iteration may include 5 modes (mode 1, mode 3, mode 5, mode 12, mode 15), then τ = 1, 2, ..., 5.

[0103] In operation S230 - 2 , a current superimposed vibration field at each of the one or more target vibration positions is calculated based on the eigenmode candidate subset for the current iteration round and its corresponding current modal participation coefficient subset.

[0104] For example, in the pth iteration round, for the target vibration position (x, y), the superimposed vibration field generated by the eigenmode candidate subset of the current iteration round and the corresponding current modal participation coefficient subset is expressed as follows:

[0105] In operation S230 - 3 , if the similarity between the current superimposed vibration field and the corresponding target vibration field at at least one target vibration position does not meet the similarity threshold condition, the current modal participation coefficient threshold condition is lowered for use in the next iteration round.

[0106] For example, for each target vibration position, the structural similarity index SSIM between the target vibration field obtained by superposition of all eigenmodes and the superposition vibration field obtained by the selected eigenmodes in formula (24) is used to determine S p >S threshold Are both true? p =SSIM(w 0 ,w p ), formula (25)

[0107] If this does not hold true for at least one target vibration position, then according to the calculation process in the pth iteration round, the current modal participation coefficient threshold is updated, for example, the current threshold is lowered to obtain a threshold p The threshold for the next iteration (i.e., the p+1th iteration): a threshold p =a threshold p-1 -δ, formula (26)

[0108] Where δ is the iterative step size of the participating parameter threshold, which is generally set to [0.01, 0.05]*max{a n 0 It should be pointed out that a step size that is too large will cause the final result to deviate from the optimal critical structure, while a step size that is too small will affect the iteration efficiency.

[0109] In operation S230-4, if the similarity between the current superimposed vibration field and the corresponding target vibration field at each of the one or more target vibration positions satisfies the similarity threshold condition, the eigenmode candidate subset for the current iteration round is determined as the eigenmode subset for modal superposition.

[0110] If S p >S threshold If the condition is established (for each target vibration position), it means that the current superimposed vibration field is close enough to the target vibration field, so similar local vibration tactile feedback can be generated with a smaller number of eigenmodes. Therefore, the multiple candidate eigenmodes used for superimposing to generate the current superimposed vibration field can be selected as the eigenmodes ultimately used for superposition.

[0111] In order to more clearly describe the iterative process, FIG4 shows an algorithm flow chart associated with the iterative process.

[0112] First, in process 1, according to the reference vibration field w at the target vibration position (shown as 1 in the spatial position grid, it is assumed here that there is 1 target vibration position, but as mentioned above, there can be more target vibration positions) r Determine the reference modal participation coefficient a corresponding to all eigenmodes n r (For example, the one determined based on formula (15) above), and the target vibration field (i.e., the target vibration field w t ), the target vibration field is also the vibration field of all modal superpositions, which serves as the benchmark for the subsequent structural similarity comparison, so it is also expressed as w 0 In addition, in the process 1, the initial threshold value a of the modal participation coefficient is also set. threshold r0 and similarity threshold Sthreshold .

[0113] In process 2, based on the current modal participation coefficient threshold, all reference modal participation coefficients a are selected. n r One or more modal participation coefficients greater than the threshold are selected, and according to the selected one or more modal participation coefficients, one or more corresponding eigenmodes are selected from the eigenmode set as the current eigenmode candidate subset.

[0114] In process 3, based on the selected current eigenmode candidate subset and the corresponding reference coefficients, the superimposed vibration field w at the target vibration position is determined. p .

[0115] In process 4, the currently determined superimposed vibration field w is calculated p With the target vibration field w 0 (i.e. target vibration field w t )'s structural similarity coefficient S p , and in process 5, the similarity threshold S is calculated. threshold Make a comparison.

[0116] If S p Greater than the similarity threshold S threshold , it means that the currently selected eigenmode subset is sufficient to generate a superimposed vibration field that meets the requirements. Therefore, in process 6, the drive control information can be determined according to the currently selected eigenmode subset to be used for the drive circuit to generate the drive signal applied to each vibration component; if S p Not greater than the similarity threshold S threshold , then in process 7, adjust (for example, reduce) the current modal participation coefficient threshold, for example, a threshold p =a threshold p-1 -δ, and then return to process 2 to recalculate all reference modal participation coefficients a n r One or more modal participation coefficients greater than the threshold value than the previous iteration round are selected, and the following process is continued.

[0117] In summary, through the above iterative process, the number of used eigenmodes can be reduced as much as possible while ensuring that the superimposed vibration field at each target vibration position is sufficiently similar to the reference (target) vibration field, thereby reducing the corresponding hardware circuit complexity (such as the number of channels) and design difficulty as well as the algorithm calculation amount.

[0118] Optionally, in conjunction with the aforementioned description of envelope wave modulation, the aforementioned process of selecting a smaller number of eigenmodes can be further combined with envelope wave modulation. Specifically, envelope wave modulation can be used to modulate at least a portion of the high-frequency vibration components of the superimposed vibration field obtained by superimposing the selected subset of eigenmodes into a low-frequency envelope wave, where the frequency of the low-frequency envelope wave is within the perceptible frequency range of human tactile sensitivity. This can be achieved, for example, by properly selecting and configuring various hardware configurations of the vibration plate. This allows for localized vibrotactile feedback while maintaining the perceptual frequency within the human perceptible frequency range (e.g., 50-500 Hz), and reduces the complexity and difficulty of system design through algorithm optimization.

[0119] The following describes an experimental system and experimental verification results of the method for generating local vibration tactile feedback according to an embodiment of the present application, so as to better illustrate that the method according to the present application can achieve better results.

[0120] First, the system for generating local vibration tactile feedback shown in Figure 1 can be used as an experimental system. First, the vibration plate is selected as a flat thin plate to simulate the plate in actual application, so as to stimulate and verify the virtual tactile feedback effect based on the aforementioned method as an experimental prototype. It should be noted that the experimental prototype is only a carrier for verifying the aforementioned method. When the size and shape of the plate changes, the specifications, quantity and arrangement position of the vibration components (for example, piezoelectric sheets) change, and / or the circuit design changes, the aforementioned method and algorithm are also feasible. The experimental system is further described in detail below.

[0121] The experimental prototype of the vibrating plate is a 203*152*1mm3 glass plate with a Young's modulus of 72GPa, a Poisson's ratio of 0.2, and a density of 2500kg / m3. The vibration component is 6 circular single-layer piezoelectric plates with a diameter of 10mm, evenly attached to the edge of the glass plate. It is used to drive the glass plate to vibrate under the excitation of a voltage drive signal and test the local vibration tactile feedback effect on the surface of the glass plate (using a laser vibration measurement device). The piezoelectric plate operates in the d33 polarization mode (vertical vibration) and drives the glass plate to form a torsional vibration. In order to better test the vibration effect of the surface through laser vibration measurement, a layer of white developer is sprayed on the surface of the glass plate to enhance the reflection intensity.

[0122] In addition, for the circuit part, the driving circuit adopts a six-channel high-voltage waveform generation circuit (for example, including a waveform generation circuit and a high-voltage amplifier circuit). Each channel can realize the output signal of any excitation waveform as the driving signal. The waveform output parameters include a voltage peak of 140Vpp, a current of 2A, and a frequency of up to 30kHz. In addition, the waveform generation circuit can be implemented by an FPGA and its related circuits. The FPGA obtains the driving control information from the processing device and then generates a six-channel voltage signal. After amplification by the voltage amplifier circuit, the driving signal with the waveform indicated in the driving control information is output to each piezoelectric piece. The circuit part also includes a power supply, as shown in Figure 1. The waveform generation circuit in the driving circuit can generate a signal of any desired waveform (10Vpp).

[0123] In terms of eigenmode identification, all eigenmodes of the above-mentioned glass plate are obtained by a laser vibrometer. The laser vibrometer can perform laser vibrometer based on optical interference and the distance of the Doppler frequency shift effect. This process is well known in the art and will not be described here to avoid blurring the focus of this application. The waveform generation circuit can also provide the required reference signal for the laser vibrometer process, and all experimental results (for example, the acquisition of local vibration patterns later) are measured using laser vibrometer. During eigenmode identification, the frequency response obtained by the laser vibrometer process can be shown in Figure 5, where each mode is identified by a peak determination method, that is, there is an eigenmode at each peak. It can be seen that the resonant frequency is in the range of 50-5000Hz. All modes are lightly damped (attenuation coefficient <0.01). Based on the above method, 42 eigenmodes are identified, as shown in the table in Figure 6. It can be seen that the difference between the resonant frequencies associated with adjacent eigenmodes is around 100Hz, which is located in the human tactile sensitive frequency range (50-500Hz). According to formula (20), the vibrations at these frequency differences can be perceived by the human body. In other words, the hardware configuration of the vibration plate selected during the experiment (e.g., boundary conditions, plate aspect ratio, and order (i, j)) can achieve the effect of envelope wave modulation, that is, when a modal superposition process is required, more high-order eigenmodes of all eigenmodes can be superimposed, while ensuring that the frequency of the superimposed vibration field is within the perceptible low-frequency frequency domain. Since the wavelength of the high-frequency vibration component is shorter, this characteristic is maintained, so the tactile feedback effect achieved also has a higher resolution (smaller area).

[0124] The voltage calculation is performed by the processing unit. After identifying all eigenmodes, they are stored as a complex matrix, including the amplitude and phase information of each eigenmode's corresponding mode shape. Unlike the theoretical assumption that vibrations at discrete locations on a vibrating plate are either in the same direction (phase 0°) or in opposite directions (phase 180°), the phase field of vibrations at discrete locations in experiments or practical applications is not binary but may range from [-10°, 10°] to [170°, 190°], necessitating a complex matrix description.

[0125] Next, the experimental verification results of the method for generating local vibration tactile feedback according to the embodiment of the present application are described below.

[0126] First, consider the effect of single-point local vibration tactile feedback. The eigenmode subset selected through the above iterative process includes only nine eigenmodes to achieve single-point local vibration. The verification results are shown in Figures 7(a) and 7(b). Figure 7(a) shows the designed local vibration tactile feedback effect as the target, and Figure 7(b) shows the actual measurement result through the laser vibrometer process (for illustration, the area with larger amplitude is indicated by a white circle in the figure). It can be seen that the trends of the two are consistent, and the vibration is strongest at almost the same target vibration position. It should be noted that due to the reduction in the number of modes and the modulation of the envelope wave, the vibration in other areas is not restricted here except for the target local vibration area where the target vibration position is located. Figures 7(c)-7(d) show the vibration displacement distribution along the x-direction and y-direction, respectively. It can be seen that the diameter of the high-amplitude area (characterized by the vibration velocity that is easier to measure) is as small as 3 cm, so the resolution is high.

[0127] Figure 8(a) further shows the velocity information of the vibration field at the target vibration position in Figures 7(a)-7(d) (the vibration plate can be divided into multiple areas, and a position in each area is used to represent the area. The target vibration position can be the center position of the area). It can be seen that the curve is periodic in the time domain space (Figure 8(a)), and all the selected modes in the frequency space are clearly visible (Figure 8(b)) and consistent with the design. In order to further demonstrate the aforementioned envelope wave modulation, the envelope distribution of the curve is given by Hilbert transform (Figure 8(c)), where the envelope wave frequency of about 170Hz is clearly visible in the frequency space (Figure 8(d)), and 170Hz is within the frequency range where human tactile perception is most sensitive, so it can be well perceived.

[0128] As mentioned above, the number of target vibration positions can be one or more. Next, the effect when there are two target vibration positions is presented, that is, the verification of the two-point local vibration tactile feedback effect. By providing different reference vibration fields, the method of the present application can control the amplitude ratio between different target vibration positions (local vibration positions). As shown in Figures 9(a)-9(c) (for illustration, the areas with larger amplitudes are shown with white circles in the figure), a two-point local vibration tactile feedback is designed, and the reference vibration fields at the two target vibration positions are given so that the local vibration areas at the two target vibration positions are close, and the amplitude ratio of the vibrations at the two target vibration positions is about 2:1 (Figure 9(a)). The experimental measurement results are shown in Figures 9(b)-9(c), and the amplitude ratio satisfies 2:1. The advantage of this is that it allows the human body to perceive different tactile feedback effects with multiple fingers.

[0129] In addition, based on the verification of the two-point local vibration tactile feedback effect, the superiority of the method proposed in this application in designing more complex multi-point local vibration tactile patterns is also demonstrated. The method proposed in this application can effectively reduce the number of eigenmodes used under any number of reference vibration field requirements, while the quality of the local vibration pattern at each target vibration position (target local vibration area) is still acceptable. Figures 10(a)-10(f) show the realization of a 5-point tactile feedback effect (for illustration, the area with larger amplitude is shown by a white circle in the figure), in which only about 10 eigenmodes are used, but clear local vibration modes are still visible. It should be pointed out that the number of modes can be adjusted according to the requirements for the local vibration effect. Figures 10(a) and 10(c) respectively show the calculation results of using the superposition of all eigenmodes and using some selected eigenmodes, and the global similarity SSIM of the two is greater than 0.4. In contrast, through the method of the present application, the number of eigenmodes used can be reduced from 42 (Figure 10(b)) to 12 (Figure 10(d)), greatly reducing the amount of calculation, hardware and system implementation difficulty. Figure 10(e) presents the measured results based on the same experimental prototype, which is consistent with the design goals, where the vibration area has a diameter of approximately 3.5 cm. As mentioned above, it is expected that while reducing the number of eigenmodes used for superposition, the similarity of the results to the preset local vibration target (peak value) can be ensured as much as possible. Figure 10(f) presents the local SSIM, where a 5*5 pixel grid is selected for each local area. The calculation results show that the local SSIM values ​​at the five target vibration positions (i.e., the structural similarity coefficient values ​​of the target vibration field and the superimposed vibration field at each target vibration position) are all as high as 0.9, which indicates that the local vibration tactile feedback effect generated by the method of the present application is highly similar to the local vibration tactile feedback effect obtained by superimposing all eigenmodes. This also proves that in the case of multi-point local vibration tactile feedback, the method of the present application can also simplify the circuit and system design while ensuring the realization of the desired multi-point local vibration tactile feedback effect.

[0130] In summary, the method for generating local vibration tactile feedback proposed in this application can realize local one or more point vibration tactile feedback with corresponding system design while controlling the perception frequency within a frequency range that can be better perceived (50Hz-500Hz), and reduce the complexity and difficulty of system design.

[0131] According to another aspect of the present application, a device for generating localized vibrotactile feedback at a target vibration position on a vibration plate is provided.

[0132] FIG11 shows a structural block diagram of an apparatus 1100 for generating localized vibrotactile feedback at a target vibration position on a vibration plate according to an embodiment of the present application.

[0133] The apparatus 1100 may include a determination module 1110 , a selection module 1120 , and a drive control module 1130 .

[0134] The determination module 1110 can be used to determine a reference modal participation coefficient set corresponding to the eigenmode set associated with the vibrating plate based on the target vibration position and the reference vibration field at the target vibration position, and determine the target vibration field at the target vibration position based on the eigenmode set and the reference modal participation coefficient set.

[0135] The selection module 1120 may be configured to select an eigenmode subset for modal superposition from the eigenmode set, and determine a modal participation coefficient subset corresponding to the eigenmodes in the eigenmode subset, wherein a superimposed vibration field at the target vibration position generated based on the eigenmode subset and its corresponding modal participation coefficient subset meets a preset similarity requirement with the target vibration field.

[0136] The drive control module 1130 can be used to determine drive control information based on the eigenmode subset and its corresponding modal participation coefficient subset and the position of the vibration component at the vibration plate, wherein the drive control information is used to drive the vibration component to generate the local vibration tactile feedback at the target vibration position.

[0137] The operations performed by the determination module 1110 may correspond to the contents described above with reference to method steps S210-230 in FIG2 , the operations performed by the selection module 1120 may refer to the contents described with reference to method step S230, and the operations performed by the drive control module 1130 may refer to the contents described with reference to method step S240. For more details on the operations performed by each module, please refer to the previous description, and therefore will not be repeated here.

[0138] Optionally, the device 1100 may also include other modules, or the various modules of the device may be divided in different ways, or may be further divided into more sub-modules. Each module or sub-module may be implemented by a dedicated hardware-based system (e.g., a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component) that performs a specified function or operation, or may be implemented by a combination of dedicated hardware and computer instructions. More details of each module can be found in the previous specific description and will not be repeated here.

[0139] According to another aspect of the present application, a computing device is provided, which may be a processing device as shown in FIG1 , configured to execute the method for generating localized vibrotactile feedback at a target vibration position on a vibration plate according to an embodiment of the present application.

[0140] As an example, the computing device of the present application may include a processor and a memory connected via a system bus, and may also include a network interface, an input device, a display screen, and the like. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer executable program. When the computer executable program is executed by the processor, the processor may perform various operations as described above with respect to the computing device. The internal memory may also store a computer executable program. When the computer executable program is executed by the processor, the processor may perform various operations as described above with respect to the computing device.

[0141] The processor can be an integrated circuit chip with signal processing capabilities. The above-mentioned processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, for implementing or executing the various methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor, and can be an X84 architecture or an ARM architecture.

[0142] The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. It should be noted that the memory of the methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0143] The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the terminal housing, or an external keyboard, touchpad or mouse.

[0144] It should be noted that the flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the methods and devices according to various embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or a part of the code, and the module, program segment, or a part of the code contains at least one executable instruction for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart, or the various modules mentioned, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0145] The embodiments of the present application described in detail above are merely illustrative and not restrictive. Those skilled in the art will appreciate that various modifications and combinations may be made to these embodiments or their features without departing from the principles and spirit of the present application, and such modifications should fall within the scope of the present application.

Claims

1. A method for generating localized vibration tactile feedback, for generating the localized vibration tactile feedback at a target vibration position on a vibration plate, the method comprising: Determining a reference modal participation coefficient set corresponding to an eigenmode set associated with the vibration plate based on the target vibration position and a reference vibration field at the target vibration position; Determining a target vibration field at the target vibration position based on the eigenmode set and the reference mode participation coefficient set; Selecting an eigenmode subset for modal superposition from the eigenmode set, and determining a modal participation coefficient subset corresponding to the eigenmode subset, wherein a superimposed vibration field generated based on the eigenmode subset and its corresponding modal participation coefficient subset meets a preset similarity requirement with the target vibration field; as well as Based on the eigenmode subset and its corresponding modal participation coefficient subset and the position of the vibration component at the vibration plate, drive control information is determined, wherein the drive control information is used to drive the vibration component to generate the local vibration tactile feedback at the target vibration position.

2. The method according to claim 1, wherein: Each eigenmode is associated with a corresponding resonant frequency, and the hardware configuration parameters of the vibration plate are set so that the frequency difference between two resonant frequencies associated with every two adjacent eigenmodes in the eigenmode set sorted by the frequency values ​​of the resonant frequencies is within the tactile sensitive frequency range.

3. The method according to claim 1, wherein: The target vibration position includes one or more target vibration positions, Wherein, selecting an eigenmode subset for modal superposition from the eigenmode set comprises: Selecting candidate eigenmodes for modal superposition as eigenmode candidate subsets from the eigenmode set in increasing numbers in different iteration rounds until an iteration termination condition is reached, The iteration termination condition includes that one or more superimposed vibration fields at the one or more target vibration positions determined based on the eigenmode candidate subset selected in the latest iteration round and its corresponding modal participation coefficient subset and the corresponding target vibration field meet a similarity threshold condition, wherein satisfying the preset similarity requirement depends on satisfying the similarity threshold condition.

4. The method according to claim 3, wherein: Selecting eigenmode candidate subsets from the eigenmode set in different iteration rounds in increasing numbers, including: for each iteration round, Based on the reference modal participation coefficient set and the current modal participation coefficient threshold condition, selecting an eigenmode candidate subset for the current iteration round from the eigenmode set, and determining a current modal participation coefficient subset corresponding to the eigenmode candidate subset for the current iteration round; Calculating a current superimposed vibration field at each of the one or more target vibration positions based on the eigenmode candidate subset for the current iteration round and its corresponding current modal participation coefficient subset; When the similarity between the current superimposed vibration field and the corresponding target vibration field at at least one target vibration position does not satisfy the similarity threshold condition, lowering the current modal participation coefficient threshold condition for use in the next iteration round; and In a case where the similarity between the current superimposed vibration field and the corresponding target vibration field at each of the one or more target vibration positions satisfies the similarity threshold condition, the eigenmode candidate subset for the current iteration round is determined as the eigenmode subset for modal superposition.

5. The method according to claim 4, wherein: Selecting an eigenmode candidate subset for a current iteration round from the eigenmode set based on the reference modal participation coefficient set and a current modal participation coefficient threshold condition, comprising: Determining whether each reference modal participation coefficient in the reference modal participation coefficient set satisfies a current modal participation coefficient threshold condition; and The eigenmodes corresponding to the reference modal participation coefficients that meet the current modal participation coefficient threshold condition are determined as the eigenmode candidate subset for the current iteration round.

6. The method according to claim 4, wherein: Lowering the current modal participation coefficient threshold condition includes: reducing a threshold corresponding to the current modal participation coefficient threshold condition by a predetermined amplitude, so that the number of eigenmodes included in the eigenmode candidate subset for subsequent iteration rounds increases.

7. The method according to claim 4, wherein: The similarity between the current superimposed vibration field and the target vibration field is defined based on a structural similarity index, The structural similarity index is related to the average vibration displacement, the standard deviation of the vibration displacement and the similarity of the vibration field structures of the two vibration fields.

8. The method according to claim 1, wherein: The target vibration position is one or more discrete positions among a preset number of discrete positions on the vibration plate, Wherein, the vibration plate is divided into a plurality of local vibration regions in rows and columns, and each discrete position in the preset number of discrete positions corresponds to a local vibration region; The reference vibration field matrix is ​​used to represent the reference vibration field at the preset number of discrete positions, wherein the elements corresponding to the target vibration positions in the reference vibration field matrix are 1, and the elements corresponding to the discrete positions other than the target vibration positions are 0.

9. The method according to claim 8, wherein: Determining a reference modal participation coefficient set corresponding to an eigenmode set associated with the vibration plate based on the target vibration position and a reference vibration field at the target vibration position includes: For each discrete position of the preset number of discrete positions, determining a vibration field representation at the discrete position based on a measured mode shape of each eigenmode at the discrete position and an unknown modal participation coefficient corresponding to each eigenmode; and The value of the modal participation coefficient corresponding to each eigenmode is adjusted, and the value of each modal participation coefficient when the sum of the differences between the vibration field representation at each discrete position and the corresponding reference vibration field is minimized is used as the reference modal participation coefficient set.

10. A device for generating local vibration tactile feedback, for generating local vibration tactile feedback at a target vibration position on a vibration plate, the device comprising: a determination module, configured to determine a reference modal participation coefficient set corresponding to an eigenmode set associated with the vibration plate based on the target vibration position and a reference vibration field at the target vibration position, and determine a target vibration field at the target vibration position based on the eigenmode set and the reference modal participation coefficient set; A selection module, configured to select an eigenmode subset for modal superposition from the eigenmode set, and determine a modal participation coefficient subset corresponding to the eigenmode subset, wherein a superimposed vibration field generated based on the eigenmode subset and its corresponding modal participation coefficient subset meets a preset similarity requirement with the target vibration field; as well as A drive control module is used to determine drive control information based on the eigenmode subset and its corresponding modal participation coefficient subset and the position of the vibration component at the vibration plate, wherein the drive control information is used to drive the vibration component to generate the local vibration tactile feedback at the target vibration position.

11. The device according to claim 10, wherein: Each eigenmode is associated with a corresponding resonant frequency, and the hardware configuration parameters of the vibration plate ensure that the frequency difference between two resonant frequencies associated with every two adjacent eigenmodes in the eigenmode set sorted by the frequency values ​​of the resonant frequencies is within the tactile sensitive frequency range.

12. The device according to claim 10, wherein: The target vibration position includes one or more target vibration positions, Wherein, when the selection module selects the eigenmode subset for modal superposition from the eigenmode set, it is configured as follows: Selecting candidate eigenmodes for modal superposition as eigenmode candidate subsets from the eigenmode set in increasing numbers in different iteration rounds until an iteration termination condition is reached, The iteration termination condition includes that one or more superimposed vibration fields at the one or more target vibration positions determined based on the eigenmode candidate subset selected in the latest iteration round and its corresponding modal participation coefficient subset and the corresponding target vibration field meet a similarity threshold condition, wherein satisfying the preset similarity requirement depends on satisfying the similarity threshold condition.

13. A computing device comprising: processor; as well as A memory having a computer program stored thereon, wherein the computer program, when executed by the processor, can execute the method as claimed in any one of claims 1 to 9.

14. A system for generating localized vibrotactile feedback, comprising: A vibration plate is provided with a plurality of vibration components; a laser vibrometer for measuring a set of eigenmodes associated with the vibrating plate; a processing device, configured to obtain a reference vibration field at the target vibration position and the set of eigenmodes obtained by the laser vibrometer, and execute the method according to claim 1; by and The driving circuit is used to generate and output a driving signal to drive the multiple vibration components based on the driving control information from the processing device, so that the multiple vibration components drive the vibration plate to vibrate.

15. The system according to claim 14, wherein the driving circuit comprises a waveform generating circuit and a voltage amplifying circuit, The waveform generating circuit generates a multi-channel voltage signal having a waveform for multiple channels indicated by the driving control information based on the driving control information; The voltage amplifying circuit is used to perform voltage amplification on the multi-channel voltage signal to generate a driving signal for driving the multiple vibration components.

16. The system of claim 14, wherein: The plurality of vibration components are a plurality of piezoelectric sheets arranged around the vibration plate.

17. The system of claim 14, wherein: The hardware configuration parameters of the vibration plate ensure that the frequency difference between two resonance frequencies associated with every two adjacent eigenmodes in the eigenmode set sorted by the frequency values ​​of the resonance frequencies is within the tactile sensitive frequency range.

Images