Method, apparatus, and system for generating local vibratory haptic feedback, and computing device

Abstract

A method, apparatus, and system for generating a local vibratory haptic feedback, and a computing device are provided. The method may comprise: on the basis of a target vibration position and a reference vibration field at the target vibration position, determining an intrinsic mode set and a reference mode participation coefficient set associated with a vibration patch; on the basis of the intrinsic mode set and the reference mode participation coefficient set, determining a target vibration field at the target vibration position; on the basis of 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, wherein a superposed vibration field generated on the basis of the intrinsic mode subset and the mode participation coefficient subset corresponding to the intrinsic mode subset meets a preset similarity requirement with respect to the target vibration field; and on the basis of the intrinsic mode subset, the mode participation coefficient subset corresponding to the intrinsic mode subset, and the position of a vibration assembly, determining driving control information, wherein the driving control information is used for driving the vibration assembly to generate a local vibratory haptic feedback at the target vibration position.

Description

Methods, apparatus, and systems for generating localized vibration tactile feedback, as well as computing devices. Technical Field

[0001] This application relates to the field of touch technology, and more specifically, to a method, apparatus, system, and computing device for generating local vibration tactile feedback at a target vibration location on a vibrating plate. Background Technology

[0002] Haptic feedback is an essential interaction channel for achieving immersive interaction. Beyond audiovisual interaction, virtual haptics can be integrated into various interactive media, such as mobile phones, tablets, and in-vehicle displays, greatly enhancing the human-computer interaction experience. Haptic feedback is fundamental to many applications, including human-computer interface design, assistive devices for the blind, and gaming. In recent years, haptic feedback technology, traditionally used for basic functions such as vibration alerts and press confirmations, has evolved towards achieving more complex and refined haptic feedback effects, primarily including localized vibration and texture pattern reproduction.

[0003] Traditional vibration tactile feedback only achieves overall vibration and cannot achieve localized vibration tactile feedback over smaller areas, thus failing to achieve more complex and refined tactile feedback effects. In addition, when achieving localized vibration tactile feedback effects based on high-frequency vibration or electrostatic friction modulation, it may not be easy to control the frequency within the frequency range that human tactile perception is most sensitive to (e.g., 50-500Hz).

[0004] Therefore, there is a need for a method that can simultaneously provide local vibration tactile feedback and whose vibration frequency is located in the frequency range that the human body is most sensitive to (e.g., 50-500Hz).

[0005] Summary of the Invention

[0006] According to one aspect of this application, a method for generating local vibration tactile feedback at a target vibration location on a vibrating plate is provided, comprising: determining a set of reference modal participation coefficients corresponding to an intrinsic mode set associated with the vibrating plate based on the target vibration location and a reference vibration field at the target vibration location; determining a target vibration field at the target vibration location based on the intrinsic mode set and the set of reference modal participation coefficients; selecting an intrinsic mode subset for modal superposition from the intrinsic mode set and determining a modal participation coefficient subset corresponding to the intrinsic mode subset, wherein the superimposed vibration field generated based on the intrinsic mode subset and its corresponding modal participation coefficient subset satisfies a preset similarity requirement with the target vibration field; and determining driving control information based on the intrinsic mode subset, its corresponding modal participation coefficient subset, and the position of a vibration component at the vibrating plate, wherein the driving control information is used to drive the vibration component to generate the local vibration tactile feedback at the target vibration location.

[0007] According to another aspect of this application, an apparatus for generating local vibration tactile feedback at a target vibration location on a vibrating plate is also provided, comprising: a determining module, configured to determine a set of reference modal participation coefficients corresponding to an intrinsic mode set associated with the vibrating plate based on the target vibration location and a reference vibration field at the target vibration location, and to determine a target vibration field at the target vibration location based on the intrinsic mode set and the set of reference modal participation coefficients; a selecting module, configured to select an intrinsic mode subset for modal superposition from the intrinsic mode set, and to determine a modal participation coefficient subset corresponding to the intrinsic mode subset, wherein the superimposed vibration field generated based on the intrinsic mode subset and its corresponding modal participation coefficient subset satisfies a preset similarity requirement with the target vibration field; and a driving control module, configured to determine driving control information based on the intrinsic mode subset and its corresponding modal participation coefficient subset and the position of a vibration component at the vibrating plate, wherein the driving control information is used to drive the vibration component to generate the local vibration tactile feedback at the target vibration location.

[0008] According to another aspect of this application, a computing device is also provided, comprising: a processor; and a memory having a computer program stored thereon, the computer program being executed by the processor to perform the method described above for generating local vibration tactile feedback at a target vibration location on a vibrating plate.

[0009] According to another aspect of this application, a system for generating local vibration tactile feedback at a target vibration location on a vibrating plate is also provided, comprising: a vibrating plate having a plurality of vibration components; a laser vibration measuring device for measuring an intrinsic mode set associated with the vibrating plate; a processing device for acquiring a reference vibration field at the target vibration location and the intrinsic mode set obtained by the laser vibration measuring device, and executing the method described above for generating local vibration tactile feedback at the target vibration location on the vibrating plate; 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 vibration components, such that the plurality of vibration components cause the vibrating plate to vibrate.

[0010] Through the examples in this application, a smaller number of intrinsic modes are selected for superposition by comparing the similarity between vibration fields to achieve a local vibration tactile feedback effect. This reduces the corresponding circuit and hardware complexity, as well as the computational load of the algorithm, and facilitates the implementation of complex (e.g., multi-point local vibration) and high-resolution (area as small as 3 cm) tactile feedback effects. Furthermore, by appropriately selecting the hardware configuration of the vibration plate, envelope wave modulation can be achieved, thereby ensuring that the vibration frequency is within the frequency range most sensitive to human perception (e.g., 50-500 Hz), further enhancing the vibration effect. Attached Figure Description

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

[0012] Figure 1 shows a schematic diagram of a system for generating local vibration tactile feedback at a target vibration location on a vibrating plate according to an embodiment of the present application.

[0013] Figure 2 shows a schematic flowchart of a method for generating local vibration tactile feedback at a target vibration location on a vibrating plate according to an embodiment of this application.

[0014] Figure 3 shows a flowchart of the process of selecting a subset of intrinsic modes in step S230 of Figure 2.

[0015] Figure 4 shows the algorithm flowchart for selecting a subset of intrinsic modes in step S230 of Figure 2.

[0016] Figure 5 shows a schematic diagram of the frequency response obtained during the laser vibration measurement process.

[0017] Figure 6 shows a table illustrating the 42 intrinsic modes identified by the laser vibrometric process.

[0018] Figure 7(a) shows the effect of the designed local vibration tactile feedback as a target.

[0019] Figure 7(b) shows the measured effect of local vibration tactile feedback obtained through laser vibration measurement process.

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

[0021] Figures 8(a)-8(d) further illustrate the velocity information of the vibration field at the target vibration location in Figures 7(a)-7(d).

[0022] Figure 9(a) shows the effect of the designed two-point local vibration tactile feedback as a target.

[0023] Figures 9(b)-9(c) show the measured results of the two-point local vibration tactile feedback obtained through the laser vibration measurement process.

[0024] Figures 10(a)-10(f) show the tactile feedback effect of local vibration at 5 points obtained through laser vibrometric measurement, using only about 10 intrinsic modes.

[0025] Figure 11 shows a structural block diagram of an apparatus for generating local vibration tactile feedback at a target vibration location on a vibrating plate according to an embodiment of this application. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] This disclosure is mainly used to generate local vibration tactile feedback at one or more target vibration locations on a vibrating plate. To better describe this disclosure, the vibration generation principle at various locations on the vibrating plate is first briefly introduced.

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

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

[0030] in, Let φ be the bending mode of a rectangular plate at position (x, y), ω be the initial phase, and ω be the angular frequency. Then the mode shape equation of the bending mode can be expressed as:

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

[0032] The resonant frequency f can also be obtained from the natural angular frequency. n , λ ij It depends only 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 vibration mass, the mode shape satisfies orthogonality:

[0033] Where δ kl It is the Kronecker symbol. Let k represent the normalized mode. Due to orthogonality and an infinite number of bending modes, the mode shape... This constitutes a complete set of bases. That is, any periodic vibration can be represented by modal decomposition as follows:

[0034] There are infinitely many modes, η n It is the modal participation coefficient (weight, the degree of contribution of this mode to the desired local vibration tactile feedback effect) of the nth intrinsic mode. It is the nth intrinsic mode shape, φ n Let be the initial phase of the nth eigenmode. Based on the orthogonality and integrity of the eigenmode shapes, any artificially designed local vibration effect can be constructed, i.e., the desired vibration field varying with time t at position (x, y). The superposition vibration field of infinitely many modes can also be expressed in complex form as:

[0035] in The complex form of the modal participation coefficients 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 experimentally (i.e., higher-order modes are not easily obtained). Therefore, assuming the first N modes are available, the superimposed vibrational field w(x,y,t) of the N modes can be represented by truncated modes as follows:

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

[0037] Figure 1 shows a schematic diagram of a system for generating local vibration tactile feedback at a target vibration location on a vibrating plate according to an embodiment of this application. Optionally, the number of target vibration locations can be one or more.

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

[0039] The vibrating plate 110 can be equipped with multiple vibration components (e.g., multiple piezoelectric sheets disposed on the four edges of the vibrating plate), each vibrating under a corresponding drive signal, thereby generating local vibration tactile feedback at the target vibration location on the vibrating plate. The vibrating plate 110 can be a carrier for various integrated tactile feedback mechanisms, such as a glass plate, display screen, touchpad, smart surface, etc., which can enhance the human-computer interaction experience, as shown in Figure 1.

[0040] The laser vibration measurement device 120 (e.g., including a laser Doppler vibration meter and its corresponding vibration controller) is used to measure the intrinsic mode set of a vibrating plate and various vibrations on the vibrating plate. For example, the vibration controller can acquire a vibration reference signal for use during laser vibration measurement. For a uniform, isotropic, and homogeneous thin plate, deformation mainly occurs in the direction perpendicular to the plane, which can be used to achieve tactile feedback. Furthermore, for a vibrating plate of any material and properties, there are corresponding multiple intrinsic modes that are inherent and related to the inherent hardware configuration of the vibrating plate, and once one or more of these intrinsic modes are excited, tactile feedback can be achieved on the vibrating plate 110 by superimposing the excited intrinsic modes. Therefore, after determining the material, size, and other various hardware parameters of the vibrating plate, the laser vibration measurement device 120 can be used to measure the intrinsic mode set of the vibrating plate (e.g., based on the frequency response and using a peak determination method (i.e., each peak has an intrinsic mode)). After identifying the set of intrinsic modes, 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 vibration measurement device.

[0041] The processing device 130 is used to acquire the intrinsic mode set measured by the laser vibration measuring device, and generate drive control information based on the target vibration position where local vibration tactile feedback is expected to occur and its reference vibration field (in actual processing, for ease of calculation, the reference vibration field at the target vibration position can be set to 1, that is, the amplitude at the target vibration position at a certain time (e.g., t=0) is set to 1). This information is used to control the drive circuit to generate drive signals for driving multiple vibration components, thereby generating local vibration tactile feedback at the target vibration position. The process by which the processing device generates drive control information will be described in detail later. The processing device 130 can be any device with processing capabilities and can be implemented using a combination of hardware and software. For example, the processing device may include a memory and a processor, so that the processor can execute a computer program stored in the memory.

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

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

[0044] Each channel can output a voltage signal with arbitrary excitation waveform. The number of channels can be the same as the number of vibration components, thereby achieving one-to-one driving of the vibration components. In this way, the driving control information (voltage information) calculated by the processing device 130 for driving the vibration components is converted into actual voltage signals by the driving circuit to drive (excite) the corresponding vibration component (e.g., a piezoelectric sheet) to produce vibration. Optionally, the waveform generation circuit also provides a reference signal when scanning the vibration field with laser vibrometer.

[0045] It should be understood that Figure 1 only illustrates several components within system 100 and does not constitute a limitation on the components included in the system. In practice, the system may include more components. For example, system 100 may also include a power module (e.g., a battery or voltage converter, etc.) to supply power to components within the system, such as processing devices and drive circuits.

[0046] Figure 2 shows a schematic flowchart of a method for generating local vibration tactile feedback at a target vibration location on a vibrating plate according to an embodiment of this application. The method shown in Figure 2 can be executed by the controller in Figure 1.

[0047] As shown in Figure 2, in step S210, based on the target vibration position and the reference vibration field at the target vibration position, the reference mode participation coefficient set corresponding to the intrinsic mode set associated with the vibration plate is determined.

[0048] Optionally, there can be one or more target vibration locations, meaning that it is desired to achieve corresponding local vibration tactile feedback at these target vibration locations (represented by multiple sets of coordinates (x,y)) through the superposition of these eigenmodes. A reference vibration field can be used to represent the desired local vibration tactile feedback at the target vibration location, and in the case of multiple target vibration locations, there are corresponding multiple reference vibration fields.

[0049] For example, the spatial grid on the vibrating plate can be divided into multiple local vibration regions arranged in S rows and T columns. Each local vibration region may have one or more discrete positions. Typically, to maximize resolution (by reducing the area of ​​the local vibration regions, thus increasing the total number of discrete positions), the area of ​​each local vibration region can be reduced, and only one position element within that region can be set to 1. That is, only one discrete position is set within each local vibration region of the vibrating plate, represented by only one corresponding coordinate (x, y). A reference vibration field matrix can be used to represent the reference vibration field at the predetermined number of discrete positions. For example, the 0 and 1 values ​​at each position of the S-row and T-column reference vibration field matrix corresponding to the region matrix can indicate whether vibration is expected at the corresponding discrete position on the vibrating plate. The element in the reference vibration field matrix corresponding to the target vibration position is set to 1, and the elements at other positions are set to 0. Of course, the reference vibration field can also be set in other ways. For example, the element corresponding to one target vibration position in the reference vibration field matrix can be set to 1, and the element corresponding to another target vibration position can be set to 2, so that the amplitude of the vibration at the two target vibration positions is approximately twice that at the same time.

[0050] Optionally, in determining the reference modal participation coefficient based on the reference vibration field, for each of the preset number of discrete positions on the vibrating plate, the vibration field representation at the discrete position can be determined based on the measured mode shape of each intrinsic mode at the discrete position and the unknown modal participation coefficient corresponding to each intrinsic mode; and the value of the modal participation coefficient corresponding to each intrinsic mode can be adjusted, and the value of the modal participation coefficient corresponding to each intrinsic mode that minimizes the sum of the differences between the vibration field representation at each discrete position and the corresponding reference vibration field can be used as the reference modal participation coefficient corresponding to each intrinsic mode in the intrinsic mode set.

[0051] For example, a reference vibration field w can be assumed at the target vibration location (x,y). r (x,y) is obtained at t=0. Of course, depending on the representation of the vibration field, the reference vibration field can also be obtained at other appropriate times or frequencies. In addition, unlike the theoretical vibration at each discrete position on the vibrating plate which is either in the same direction (phase 0°) or opposite direction (phase 180°), the phase field of the vibration at each discrete position is not actually binary, but in the range of [-10°, 10°] or [170°, 190°], and therefore is described by a complex matrix.

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

[0053] Furthermore, the coordinates (x, y) of the target vibration location can be rewritten in discrete form based on the position space grid (S rows and T columns) used when measuring the intrinsic modes. Therefore, equation (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 m-th 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. It is the mode shape of the nth eigenmode at the mth discrete position. n r Let be the modal participation coefficient corresponding to the nth eigenmode. For example, the vibration field at discrete position 1 can be represented as follows: The vibration field at discrete position 2 can be represented as follows: etc.

[0055] Equation (10) is a system of linear equations. Generally, the number of discrete positions M is much larger than the number of measurable eigenmodes N, therefore equation (10) is an overdetermined system of equations. In this case, a n r The equation set (10) cannot be strictly satisfied. To obtain the weighted participation coefficients for each intrinsic mode, which can then be used to generate local vibration tactile feedback at the target vibration location, the problem becomes finding the most suitable a... n r In other words, the superimposed vibration field obtained by superimposing these intrinsic modes cannot be completely consistent with the artificially set reference vibration field. However, the modal participation coefficients corresponding to each intrinsic mode can be determined so that the difference between the superimposed vibration field and the reference vibration field is minimized.

[0056] For example, when the preset number M of the discrete positions is greater than the first number N of the intrinsic modes in the intrinsic mode set, an overdetermined system 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 mode participation coefficients in the vibration field representation at each discrete position are used as equation variables; then, the overdetermined system of equations is solved using the least squares method to obtain the value of the reference mode participation coefficient corresponding to each intrinsic mode 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 ways.

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

[0059] Where Φ is an M×N matrix, and M>N. Formula (11) is solved using the pseudo-inverse method. 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... Let be an N×M diagonal matrix, satisfying

[0061] Then the pseudoinverse of matrix Φ It can be represented as

[0062] Modal participation coefficients can be expressed as

[0063] Therefore, the overdetermined equations can be solved using the least squares method to obtain the optimal solution for A:

[0064] In step S220, the target vibration field at the target vibration location is determined based on the intrinsic mode set and the reference mode participation coefficient set.

[0065] Theoretically, the modal participation coefficient corresponding to each intrinsic mode is determined by the reference vibration field, as shown in formula (16). However, due to the truncation of intrinsic modes (i.e., the removal of higher-order intrinsic modes that cannot be obtained through measurement), the superimposed vibration field actually obtained at each target vibration location is not exactly the same as the artificially set reference vibration field.

[0066] For example, by superimposing all N intrinsic modes and the corresponding reference mode participation coefficients obtained in step S210, and combining this with the position coordinates of the target vibration location, the target vibration field at the target vibration location can be obtained. This target vibration field will be used for subsequent comparison with the superimposed vibration field obtained based on a smaller number of intrinsic modes. Since the goal is to use as few intrinsic modes as possible while still achieving a similarity to the vibration field obtained based on the superposition of all N intrinsic modes, the vibration field obtained based on the superposition of all N intrinsic modes is called the target vibration field. The target vibration field w at the target vibration location (x, y) is... t It can be represented as follows:

[0067] In step S230, an intrinsic mode subset for modal superposition is selected from the intrinsic mode set, and a modal participation coefficient subset corresponding to the intrinsic mode subset is determined, wherein the superimposed vibration field generated based on the intrinsic mode 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 the selected subset of intrinsic modes is equal to the first number N of the set of intrinsic modes, i.e., all intrinsic modes in the set of intrinsic modes (such as the N intrinsic modes mentioned above) are used for modal superposition. In this case, the modal participation coefficient corresponding to each intrinsic mode in the subset of intrinsic modes is the same as the reference modal participation coefficient, and since all intrinsic modes are superimposed, this is already the best superposition result that can be achieved. Therefore, the generated superimposed vibration field (target vibration field) is necessarily sufficiently similar to the reference vibration field, and thus can be taken as the target to be achieved in the following parts of this paper (as one of the similarity comparisons during the iteration process).

[0069] In other cases, considering that the more eigenmodes selected, the more vibration components on the vibrating plate there are, and the corresponding circuit complexity (e.g., number of channels) and algorithm computation increase, only a portion of the eigenmodes can be selected for superposition, as long as the required local vibration tactile feedback can be achieved at the target vibration location. Furthermore, since the original modal participation coefficients are determined based on the reference vibration field for all eigenmodes, when a smaller number of eigenmodes are determined, the corresponding modal participation coefficients need to be re-determined based on the reference vibration field and for this smaller number of eigenmodes (as shown in Equation 16). In this case, the re-determined modal participation coefficients are different from the reference modal participation coefficients corresponding to that eigenmode. The generated superimposed vibration field and the target vibration field also need to meet the similarity requirement to produce the required local vibration tactile feedback at the target vibration location.

[0070] It should be noted that, theoretically, 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 mentioned above, while the superimposed vibration field is a signal that changes with time, 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 subset of intrinsic modes can be used to generate local vibration tactile feedback at the target vibration location.

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

[0072] This application uses SSIM to evaluate the similarity between two local vibration modes (i.e., two vibration fields). Assume w 1 (x,y) and w 2 If (x,y) is a vibrational field with two sets of different modal numbers superimposed, then the formula for calculating SSIM is:

[0073] Where μ1 and μ2 are the vibrational field w 1 and w 2 The average values ​​of the vibration displacement distribution, σ1 and σ2 are w 1 and w 2 The standard deviation of the vibration displacement, σ 12 It is w 1 and w2 The covariance, C1 and C2 are two constants. This index mainly considers three key characteristics of the mode shape and expresses them as: mean vibration displacement, standard deviation of vibration displacement (contrast), and similarity of the vibration field structure (structure). SSIM adopts... and The three key features are measured separately, and the results are multiplied together. SSIM enables a quantitative assessment of the similarity between local vibration modes, thereby preserving the local vibration regions of the target.

[0074] The specific method for selecting and superimposing intrinsic modal subsets based on similarity will be described in detail later.

[0075] In step S240, driving control information is determined based on the subset of intrinsic modes and its corresponding subset of modal participation coefficients and the position of the vibration component at the vibration plate. The driving 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 in Figure 1, the vibrating components vibrate based on a drive signal (or a signal amplified by high voltage), thereby causing the vibrating plate to vibrate. The combination of drive signals applied to each vibrating component differs depending on the selected subset of intrinsic modes. For example, the drive signals required to be applied to each vibrating component when the selected intrinsic modes are mode 1 and mode 2 are different from the drive signals required when the selected intrinsic modes 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 subset of intrinsic modes (assuming there are P intrinsic modes) and the corresponding modal participation coefficients, for example:

[0078] Where Ui is the excitation voltage of the driving signal of the i-th vibration component, U am To enable the supply of voltage amplitude to each vibrating component (e.g., provided by the power supply module in Figure 1). (x) i ,y i Let be the position of the i-th vibration component, from which the mode shapes at the position of the i-th vibration component can be obtained. The phase condition. n r The modal participation coefficient is the coefficient for each of the P intrinsic modes (calculated based on the target vibration location, its reference vibration field, and the selected P intrinsic modes).

[0079] After determining the drive signal that needs to be applied to each vibration component i, the relevant information of these drive signals (i.e., drive control information) can be provided to the drive circuit capable of generating drive signals (e.g., 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] Under the drive or excitation of the corresponding voltage drive signal, the vibration component can realize local vibration tactile feedback at the target vibration position.

[0081] By referring to the method described in Figure 2 for generating local vibration tactile feedback at a target vibration location on a vibrating plate, a local vibration tactile feedback effect that is sufficiently similar to the desired local vibration tactile feedback effect can be achieved by superimposing multiple modes. Furthermore, the number of selected modes can be less than the number of modes in the intrinsic mode set, thereby reducing the corresponding circuit complexity (e.g., the number of channels) and the computational load of the algorithm.

[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 We obtain, and from formula (4), we know that the resonant frequency f of each eigenmode is... n Since it depends on the boundary conditions, the aspect ratio of the plate, and the order, it is deterministic. The superimposed vibration field generated by superimposing multiple eigenmodes may include high-frequency vibration components and low-frequency vibration components, and some high-frequency vibration components may not be within the frequency range that the human body can perceive (e.g., 50Hz to 500Hz).

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

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

[0085] Where f i f is the resonant frequency of the i-th eigenmode. min and f max Set them to 50Hz and 300Hz respectively.

[0086] In this way, by modulating the possible high-frequency vibration components in the superimposed vibration field into low-frequency envelope waves, they can be better perceived. Furthermore, because the wavelengths of the high-frequency vibration components are shorter, this characteristic is maintained, thus achieving a haptic feedback effect with higher resolution (smaller area). In other words, even when all intrinsic modes are superimposed, the superimposed vibration field is improved because it can be perceived better than existing methods.

[0087] The process of selecting a subset of intrinsic modes in step S230 of Figure 2 will be described in detail below with reference to Figures 3 and 4.

[0088] As mentioned earlier, in some cases, all the measured intrinsic modes can be superimposed and correspondingly modulated based on the envelope wave. In this way, the superimposed vibration field at the target vibration location can be as similar as possible to the reference vibration field, and a better tactile feedback effect can also be achieved.

[0089] In other cases, the number of selected intrinsic modes can be less than the total number of intrinsic modes in the intrinsic mode set, thereby reducing the corresponding circuit complexity (e.g., number of channels) and algorithm computation. The process of selecting intrinsic modes in this case will be introduced below.

[0090] As mentioned earlier, calculating all intrinsic modes on which the target vibration field is based and the participation coefficients of each reference mode on which it is based are the optimal solutions that can be obtained. Therefore, the target vibration field can be regarded as the target to be achieved by the superimposed vibration field based on fewer intrinsic modes. In addition, the number of target vibration locations can also be one or more. Therefore, candidate intrinsic modes for modal superposition can be selected from the set of intrinsic modes in an increasing manner in different iteration rounds as a subset of candidate intrinsic modes, until one or more superimposed vibration fields at the one or more target vibration locations determined based on the subset of candidate intrinsic modes and its corresponding modal participation coefficient subset selected in the latest iteration round and the corresponding target vibration field satisfy the similarity threshold condition. In this application, the similarity threshold condition can correspond to a threshold, and satisfying this condition may be greater than or less than the threshold depending on the different condition settings, etc. Similarly, the modal participation coefficient threshold condition in the following text can also be interpreted in this way, and this application does not limit it. Whether the preset similarity requirement is met depends on whether the corresponding superimposed vibration field and the target vibration field satisfy the similarity threshold condition.

[0091] For example, when there is only one target vibration location, the situation is relatively simple, that is, there is only a comparison and iteration between the superimposed vibration field and the target vibration field at a single target vibration location. When there are multiple target vibration locations, there are correspondingly multiple non-zero reference vibration fields. As mentioned above, the determination of the reference modal participation coefficient set is also based on the reference vibration fields of each discrete location (including these target vibration locations) (as shown in formulas (10) and (15)). Then, the target vibration field at each target vibration location can be determined based on the intrinsic mode set, the reference modal participation coefficient set, and each target vibration location. In addition, it can be determined whether the superimposed vibration field obtained by superimposing the currently selected intrinsic mode candidate subset and its corresponding modal participation coefficient at each target vibration location and its corresponding target vibration field satisfy the similarity threshold condition, and the iteration stops only when the superimposed vibration field obtained at each target vibration location and its corresponding target vibration field all satisfy the similarity threshold condition.

[0092] As mentioned earlier, the similarity between two vibration fields (corresponding to different subsets of intrinsic modes) can be determined based on the structural similarity index. Therefore, the similarity threshold condition here can correspond to the structural similarity threshold.

[0093] For example, it can be based on one or more reference vibration fields w r (each corresponding to one or more target vibration locations) The set of reference mode participation coefficients corresponding to all intrinsic modes calculated (a) n 0 (n is an integer between 1 and the number of all intrinsic modes N) constitute a sequence, for example, they can be numbered as

[0094] Then, set an initial threshold a. threshold 0 This threshold is used for subsequent selection of intrinsic modes. Starting from the first iteration, intrinsic modes with modal participation coefficients greater than this initial threshold are used for superposition. This threshold can be updated based on the effect of the superimposed vibration field generated by the selected intrinsic modes, thus being used for the next iteration if needed. Additionally, a similarity threshold S can also be set. threshold That is, if the similarity between the superimposed vibration field obtained based on the current intrinsic mode and the target vibration field is greater than or equal to the similarity threshold (or the superimposed vibration field or the corresponding reference vibration field at each target vibration position is greater than or equal to the similarity threshold), the iteration can be stopped.

[0095] The target vibration field at position (x, y) is represented as described above as follows:

[0096] Optionally, generally speaking, the initial threshold a threshold 0 It will be set to [0.3, 0.5] * max{a n 0}, and the similarity threshold S threshold The threshold value 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 vibration meter). It is typically set to 0.2–0.6 and can be adjusted according to the tolerance for vibration amplitude outside the desired target vibration location area (local vibration location area). Generally, within this value range, vibrations outside the target local vibration area are suppressed to a relatively small level compared to vibrations within that area. When the vibration field is highly complex, this similarity threshold can be appropriately relaxed.

[0097] The process of selecting a subset of intrinsic modes in each iteration round may include the following operations.

[0098] For example, as shown in Figure 3, in operation S230-1, based on the reference modal participation coefficient set and the current modal participation coefficient threshold condition, a subset of intrinsic modal candidates for the current iteration round is selected from the intrinsic modal set, and the current modal participation coefficient subset corresponding to the intrinsic modal candidate subset for the current iteration round is determined.

[0099] Therefore, in the first iteration, the initial threshold a threshold 0 The value is usually set relatively large, so that it can only be obtained from the participation coefficients a of all reference modes. n 0 A smaller number of modal participation coefficients exceeding the initial threshold are selected, meaning only a smaller number of intrinsic modes can be selected as the candidate subset of intrinsic modes for the current first iteration. At this point, since the selected candidate subset of intrinsic modes needs to be superimposed to maximize the realization of the reference vibration field (or target vibration field) at one or more target vibration locations, the modal participation coefficients corresponding to this candidate subset of intrinsic modes need to be re-determined based on the reference vibration field (e.g., the reference vibration field matrix) at one or more target vibration locations, serving as the current subset of modal participation coefficients. Furthermore, if subsequent operations determine that further iterations are needed, the threshold used for modal participation coefficients will be updated for other iterations, for example, by decreasing it, thus allowing the threshold to be adjusted from the reference modal participation coefficient a. n 0 In this process, more modal participation coefficients greater than the initial threshold are selected than in the first iteration, thereby selecting more intrinsic modes and recalculating the corresponding modal participation coefficients.

[0100] That is, for the p-th iteration, based on the current athreshold p-1 (Possibly the initial threshold or the threshold from the previous update), from the reference modal participation coefficient set a n 0 Select a that is greater than the current one. threshold p-1 Modal participation coefficients:

[0101] Make and Formula (23)

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

[0103] In operation S230-2, based on the subset of intrinsic modes candidate for the current iteration and the corresponding subset of current mode participation coefficients, the current superimposed vibration field at each of the one or more target vibration locations is calculated.

[0104] For example, in the p-th iteration, for the target vibration location (x, y), the superimposed vibration field generated by the candidate subset of intrinsic modes and the corresponding subset of participation coefficients of the current mode for the current iteration is represented 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 location does not meet the similarity threshold condition, the current modal participation coefficient threshold condition is reduced for use in the next iteration round.

[0106] For example, for each target vibration location, the S is determined based on the structural similarity index SSIM between the target vibration field obtained from the superposition of all intrinsic modes and the superimposed vibration field obtained from the selected partial intrinsic modes in formula (24). p >S threshold Are all of them true? S p =SSIM(w 0 ,w p ), formula (25)

[0107] If the condition is not met for at least one target vibration location, then based on the calculation process in the p-th iteration, update the current modal participation coefficient threshold, for example, by lowering the current threshold to obtain a. threshold p The threshold used for the next iteration (i.e., the (p+1)th iteration): a threshold p =a threshold p-1 -δ, Formula (26)

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

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

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

[0111] To illustrate the iterative process more clearly, Figure 4 shows the algorithm flowchart associated with the iterative process.

[0112] First, in process 1, the reference vibration field w at the target vibration location (shown as 1 in the spatial location grid; here we assume there is one target vibration location, but as mentioned earlier, there can be more target vibration locations) is used. r Determine the reference mode participation coefficient α corresponding to all intrinsic modes. n r (For example, the one determined above based on formula (15), and the target vibration field (i.e., the target vibration field w) is obtained accordingly. t The target vibration field is also the vibration field of the superposition of all modes, which serves as the benchmark for subsequent structural similarity comparison, and is therefore also represented as w. 0 Furthermore, in process 1, an initial threshold 'a' for the modal participation coefficient is set. threshold r0 and similarity threshold Sthreshold .

[0113] In process 2, the modal participation coefficients a are calculated based on the current modal participation coefficient threshold from all reference modal participation coefficients. n r Select one or more modal participation coefficients that are greater than the threshold, and select one or more corresponding intrinsic modes from the intrinsic mode set based on the selected one or more modal participation coefficients as the current intrinsic mode candidate subset.

[0114] In process 3, based on the selected subset of current intrinsic mode candidates and the corresponding reference coefficients, the superimposed vibration field w at the target vibration location 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., the target vibration field w) t Structural similarity coefficient S p Furthermore, in process 5, the calculated similarity threshold S will be compared with the value obtained from the process. threshold Compare them.

[0116] If S p Greater than the similarity threshold S threshold If the selected subset of intrinsic modes is sufficient to generate a superimposed vibration field that meets the requirements, then in process 6, the drive control information can be determined based on the selected subset of intrinsic modes to generate drive signals applied to each vibration component by the drive circuit; if S p Not greater than the similarity threshold S threshold In process 7, the current modal participation coefficient threshold is adjusted (e.g., reduced), for example, a threshold p =a threshold p-1 -δ, then return to process 2 to recalculate the participation coefficients a from all reference modes. n r Select one or more modal participation coefficients that are greater than the threshold than in the previous iteration round, and continue with the following process.

[0117] In summary, through the above iterative process, the number of intrinsic modes used can be reduced as much as possible while ensuring that the superimposed vibration field at each target vibration location is sufficiently similar to the reference (target) vibration field. This reduces the corresponding hardware circuit complexity (e.g., number of channels), design difficulty, and algorithm computation.

[0118] Optionally, in conjunction with the preceding description of envelope wave modulation, the process of selecting a smaller number of intrinsic modes can also be further combined with envelope wave modulation. That is, envelope wave modulation can be used to modulate at least a portion of the high-frequency vibration components of the superimposed vibration field obtained based on the selected subset of intrinsic modes into a low-frequency envelope wave. The frequency of this low-frequency envelope wave is within the perceptible frequency range sensitive to human touch, for example, achieved through the appropriate selection and configuration of various hardware features of the vibrating plate. In this way, while achieving local vibration tactile feedback, the perceived frequency can be controlled within the perceptible frequency range for the human body (e.g., 50-500Hz), and the system design complexity and difficulty are reduced through algorithm optimization.

[0119] The following describes the experimental system and experimental verification results of the method for generating local vibration tactile feedback according to the embodiments of this application, so as to better illustrate that the method according to this 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. The vibrating plate is selected as a thin planar plate to simulate a plate in actual application, serving as an experimental prototype to stimulate and verify the virtual tactile feedback effect based on the aforementioned method. It should be noted that this experimental prototype is only a carrier for verifying the aforementioned method. The aforementioned method and algorithm remain feasible even when the size and shape of the plate change, the specifications, quantity, and arrangement of the vibration components (e.g., piezoelectric elements) change, and / or the circuit design changes. The experimental system will be further described in detail below.

[0121] The experimental prototype of the vibrating plate was a glass plate measuring 203*152*1mm³, with a Young's modulus of 72 GPa, a Poisson's ratio of 0.2, and a density of 2500 kg / m³. The vibration assembly consisted of six 10mm diameter circular single-layer piezoelectric plates, uniformly attached to the edge of the glass plate. These plates were used to drive the glass plate to vibrate under voltage-driven excitation, and the tactile feedback effect of local vibration was tested on the glass plate surface (using a laser vibrometer). The piezoelectric plates operated in d33 polarization mode (vertical vibration), causing the glass plate to undergo torsional vibration. To better test the surface vibration effect using laser vibrometer, a layer of white developer was sprayed onto the glass plate surface to enhance reflectivity.

[0122] Furthermore, for the circuit section, the drive circuit employs a six-channel high-voltage waveform generation circuit (e.g., comprising a waveform generation circuit and a high-voltage amplifier circuit). Each channel can generate an output signal with any excitation waveform as the drive signal. The waveform output parameters include a peak voltage of 140Vpp, a current of 2A, and a frequency up to 30kHz. The waveform generation circuit can be implemented by an FPGA and its related circuitry. The FPGA obtains drive control information from the processing device, generates a six-channel voltage signal, amplifies it, and then outputs a drive signal with the waveform indicated in the drive control information to each piezoelectric element. The circuit section also includes a power supply, as shown in Figure 1. The waveform generation circuit in the drive circuit can generate a signal with any desired waveform (10Vpp).

[0123] Regarding intrinsic mode identification, all intrinsic modes of the aforementioned glass plate were acquired using a laser vibration measurement device. This device utilizes optical interferometry and the Doppler frequency shift effect for laser vibration measurement, a process known in the art and therefore not described here to avoid obscuring the focus of this application. A waveform generation circuit also provides the necessary reference signal for the laser vibration measurement process, and all experimental results (e.g., the acquisition of subsequent local vibration patterns) are measured using laser vibration measurement. The frequency response obtained during intrinsic mode identification via laser vibration measurement is shown in Figure 5, where each mode is identified using a peak determination method, meaning each peak corresponds to an intrinsic mode. It can be seen that the resonant frequencies are in the range of 50-5000Hz. All modes are lightly damped (attenuation coefficient < 0.01). Based on the above method, 42 intrinsic modes were identified, as shown in the table in Figure 6. It can be seen that the difference in resonant frequencies associated with adjacent intrinsic modes is around 100Hz, falling within the human tactile sensitivity frequency range (50-500Hz). According to formula (20), vibrations at these frequency differences can be perceived by the human body. In other words, the hardware configuration of the vibration plate selected in the experiment (e.g., boundary conditions, plate width-to-length ratio, and order (i,j)) can achieve the effect of envelope wave modulation. That is, when the modal superposition process is required, more higher-order intrinsic modes among all intrinsic modes can be superimposed, while ensuring that the frequency of the superimposed vibration field is within the perceptible low-frequency range. Furthermore, since the wavelength of the high-frequency vibration component is shorter, this characteristic is maintained. Therefore, the achieved tactile feedback effect also has higher resolution (smaller area).

[0124] Voltage calculations are performed by a processing unit. After identifying all intrinsic modes, all intrinsic modes are stored as complex matrices, including the amplitude and phase information of the corresponding mode shape for each intrinsic mode. Unlike the theoretical vibrations at discrete positions on a vibrating plate, which are either in the same direction (phase 0°) or opposite directions (phase 180°), the phase field of vibrations at discrete positions in experiments or practical applications is not binary, but may be in the range of [-10°, 10°] or [170°, 190°]. Therefore, it needs to be described using a complex matrix.

[0125] The experimental verification results of the method for generating local vibration tactile feedback according to the embodiments of this application are described below.

[0126] First, consider the tactile feedback effect of single-point local vibration. The subset of intrinsic modes selected through the above iterative process only includes 9 intrinsic modes, which is sufficient 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 measured results through laser vibration measurement (for illustration, areas with larger amplitudes are indicated by white circles). It can be seen that the trends are consistent, and the vibration is strongest at almost the same target vibration location. 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 besides the target local vibration area is not restricted. Figures 7(c)-7(d) show the vibration displacement distribution along the x and y directions, respectively. It can be seen that the diameter of the high-amplitude region (characterized by easily measurable vibration velocity) is as small as 3 cm, thus providing high resolution.

[0127] Figure 8(a) further illustrates the velocity information of the vibration field at the target vibration location in Figures 7(a)-7(d) (the vibrating plate can be divided into multiple regions, with one location in each region representing that region, and the target vibration location can be the center of that region). It can be seen that the curve exhibits periodicity in the time domain (Figure 8(a)), and all selected modes are clearly visible in the frequency space (Figure 8(b)) and consistent with the design. To further demonstrate the aforementioned envelope modulation, the envelope distribution of the curve is given using the Hilbert transform (Figure 8(c)), where the envelope frequency of approximately 170Hz is clearly visible in the frequency space (Figure 8(d)), and 170Hz is within the frequency range most sensitive to human tactile perception, thus it can be well perceived.

[0128] As mentioned earlier, the number of target vibration locations can be one or more. The following presents the effect when there are two target vibration locations, i.e., the verification of the two-point local vibration tactile feedback effect. By providing different reference vibration fields, the method of this application can control the amplitude ratio between different target vibration locations (local vibration locations). As shown in Figures 9(a)-9(c) (for illustration, the areas with larger amplitudes are indicated by white circles in the figures), two-point local vibration tactile feedback is designed, providing reference vibration fields at the two target vibration locations such that the local vibration areas at the two target vibration locations are similar, and the amplitude ratio of the vibrations at the two target vibration locations is approximately 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 through multiple fingers.

[0129] Furthermore, based on the verification of the two-point local vibration tactile feedback effect, the superiority of the proposed method in designing more complex multi-point local vibration tactile patterns is also demonstrated. The proposed method can effectively reduce the number of intrinsic modes used under any number of reference vibration fields, while the quality of the local vibration pattern at each target vibration location (target local vibration region) remains acceptable. Figures 10(a)-10(f) show the achievement of a 5-point tactile feedback effect (for illustration, areas with larger amplitudes are indicated by white circles in the figures), using only about 10 intrinsic modes, yet clear local vibration modes are still visible. It should be noted that the number of modes can be adjusted according to the requirements of the local vibration effect. Figures 10(a) and 10(c) show the calculation results using all intrinsic modes superimposed and using selected intrinsic modes, respectively, with a global similarity SSIM > 0.4. In contrast, the method described in this application reduces the number of intrinsic modes used from 42 (Fig. 10(b)) to 12 (Fig. 10(d)), significantly reducing computational complexity, hardware requirements, and system implementation difficulty. Fig. 10(e) presents the experimental results based on the same experimental prototype, consistent with the design goals, where the vibration region diameter is approximately 3.5 cm. As mentioned above, the aim is to reduce the number of intrinsic modes used for superposition while maintaining as much similarity as possible to the preset local vibration target (peak value). Fig. 10(f) shows the local SSIM, where each local region uses a 5*5 pixel grid. The calculation results show that the local SSIM values ​​(i.e., the structural similarity coefficients between the target vibration field and the superimposed vibration field at each target vibration location) at the five target vibration locations are all as high as 0.9. This indicates that the local vibration tactile feedback effect generated by the method of this application is highly similar to the local vibration tactile feedback effect obtained by superimposing all intrinsic modes. This also proves that in the case of multi-point local vibration tactile feedback, the method of this application can simplify the circuit and system design while ensuring the achievement 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, with corresponding system design, can achieve local one-point or multi-point vibration tactile feedback while controlling the sensing frequency within a frequency range that can be well sensed (50Hz-500Hz), and reduces the complexity and difficulty of system design.

[0131] According to another aspect of this application, an apparatus for generating local vibration tactile feedback at a target vibration location on a vibrating plate is also provided.

[0132] Figure 11 shows a structural block diagram of a device 1100 for generating local vibration tactile feedback at a target vibration location on a vibrating plate according to an embodiment of this application.

[0133] The device 1100 may include a determining module 1110, a selecting module 1120, and a drive control module 1130.

[0134] The determining module 1110 can be used to determine, based on the target vibration location and the reference vibration field at the target vibration location, a set of reference mode participation coefficients corresponding to the intrinsic mode set associated with the vibrating plate, and, based on the intrinsic mode set and the set of reference mode participation coefficients, a target vibration field at the target vibration location.

[0135] The selection module 1120 can be used to select a subset of intrinsic modes for modal superposition from the intrinsic mode set, and determine the modal participation coefficient subset corresponding to the intrinsic modes in the intrinsic mode subset, wherein the superimposed vibration field at the target vibration location generated based on the intrinsic mode subset and its corresponding modal participation coefficient subset meets the 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 subset of intrinsic modes and its corresponding subset of modal participation coefficients 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 can correspond to the methods described in steps S210-230 of Figure 2 above. The operations performed by the selection module 1120 can refer to the methods described in step S230, and the operations performed by the drive control module 1130 can refer to the methods described in step S240. More details about the operations performed by each module can be found in the preceding descriptions, and therefore will not be repeated here.

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

[0139] According to another aspect of this application, a computing device is also provided. This computing device may be a processing apparatus as shown in FIG1, used to execute a method according to an embodiment of this application for generating local vibration tactile feedback at a target vibration location on a vibrating plate.

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

[0141] The processor can be an integrated circuit chip with signal processing capabilities. The aforementioned processor can be 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 devices, discrete gate or transistor logic devices, or discrete hardware components, to implement or execute the 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 based on an x84 architecture or an ARM architecture.

[0142] Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. It should be noted that the memory used in the methods described in this application is intended to include, but is not limited to, these and any other suitable categories of memory.

[0143] The display screen can be an LCD screen or an e-ink screen. The input device of the computer equipment can be a touch layer covering the display screen, or buttons, trackballs or touchpads set on the terminal shell, or external keyboards, touchpads or mice, etc.

[0144] It should be noted that the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functions, and operations of possible implementations of the methods and apparatus according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, program segment, or portion of code containing at least one executable instruction for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, as well as combinations of blocks in the block diagrams and / or flowcharts, or the various modules mentioned, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

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

Claims

1. A method for generating local vibration tactile feedback, wherein the local vibration tactile feedback is generated at a target vibration location on a vibrating plate, the method comprising: Based on the target vibration location and the reference vibration field at the target vibration location, determine the reference mode participation coefficient set corresponding to the intrinsic mode set associated with the vibration plate; Based on the intrinsic mode set and the reference mode participation coefficient set, the target vibration field at the target vibration location is determined; Select an intrinsic mode subset for modal superposition from the intrinsic mode set, and determine the modal participation coefficient subset corresponding to the intrinsic mode subset, wherein the superimposed vibration field generated based on the intrinsic mode subset and its corresponding modal participation coefficient subset meets the preset similarity requirement with the target vibration field; as well as Based on the subset of intrinsic modes and its corresponding subset of modal participation coefficients, as well as 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 of claim 1, wherein, Each intrinsic mode is associated with a corresponding resonant frequency, and the hardware configuration parameters of the vibrating plate are set such that the frequency difference between the two resonant frequencies associated with every two adjacent intrinsic modes in the intrinsic mode set, sorted by the frequency value of the resonant frequency, is within the tactile sensitive frequency range.

3. The method of claim 1, wherein, The target vibration location includes one or more target vibration locations. The selection of a subset of intrinsic modes for mode superposition from the intrinsic mode set includes: From the intrinsic mode set, candidate intrinsic modes for mode superposition are selected in increasing order in different iteration rounds as a subset of candidate intrinsic modes until the iteration termination condition is met. The iteration termination condition includes determining, based on the subset of intrinsic mode candidates and their corresponding modal participation coefficient subset selected in the latest iteration, that one or more superimposed vibration fields at one or more target vibration locations and the corresponding target vibration fields satisfy a similarity threshold condition, wherein satisfying the preset similarity requirement depends on satisfying the similarity threshold condition.

4. The method of claim 3, wherein, Selecting a subset of candidate intrinsic modes from the intrinsic mode set in ascending order of quantity in different iteration rounds includes: for each iteration round, Based on the reference modal participation coefficient set and the current modal participation coefficient threshold condition, a subset of intrinsic modal candidates for the current iteration round is selected from the intrinsic modal set, and the current modal participation coefficient subset corresponding to the intrinsic modal candidate subset for the current iteration round is determined. Based on the subset of intrinsic modes candidate for the current iteration and its corresponding subset of current mode participation coefficients, calculate the current superimposed vibration field at each of the one or more target vibration locations; If the similarity between the current superimposed vibration field and the corresponding target vibration field at at least one target vibration location does not meet the similarity threshold condition, the current modal participation coefficient threshold condition is lowered for use in the next iteration round; and If the similarity between the current superimposed vibration field at each of the one or more target vibration locations and the corresponding target vibration field satisfies the similarity threshold condition, the subset of intrinsic modes candidate for the current iteration round is determined as the subset of intrinsic modes for modal superposition.

5. The method of claim 4, wherein, Based on the reference modal participation coefficient set and the current modal participation coefficient threshold condition, a subset of candidate intrinsic modes for the current iteration is selected from the intrinsic mode set, including: Determine whether each reference modal participation coefficient in the set of reference modal participation coefficients satisfies the current modal participation coefficient threshold condition; and The intrinsic modes corresponding to the reference mode participation coefficients that satisfy the current modal participation coefficient threshold conditions are determined as the candidate subset of intrinsic modes for the current iteration round.

6. The method of claim 4, wherein, Lowering the current modal participation coefficient threshold condition includes: reducing the threshold corresponding to the current modal participation coefficient threshold condition by a predetermined amount, thereby increasing the number of intrinsic modes included in the intrinsic mode candidate subset for subsequent iteration rounds.

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

8. The method of claim 1, wherein, The target vibration position is one or more discrete positions from a preset number of discrete positions on the vibrating plate. The vibrating plate is divided into multiple local vibration regions by rows and columns, and each of the preset number of discrete positions corresponds to a local vibration region. The reference vibration field at the preset number of discrete positions is represented by a reference vibration field matrix, wherein the element corresponding to the target vibration position in the reference vibration field matrix is ​​1, and the element corresponding to the discrete positions other than the target vibration position is 0.

9. The method of claim 8, wherein, Based on the target vibration location and the reference vibration field at the target vibration location, a set of reference modal participation coefficients corresponding to the intrinsic mode set associated with the vibrating plate is determined, including: For each of the predetermined number of discrete locations, based on the measured mode shape of each intrinsic mode at that discrete location and the unknown modal participation coefficient corresponding to each intrinsic mode, the vibration field representation at that discrete location is determined; and The values ​​of the modal participation coefficients corresponding to each intrinsic mode are adjusted, and the values ​​of each modal participation coefficient that minimize the sum of the differences between the vibration field representation at each discrete position and the corresponding reference vibration field are used as the reference modal participation coefficient set.

10. An apparatus for generating localized vibration tactile feedback, for generating localized vibration tactile feedback at a target vibration location on a vibrating plate, the apparatus comprising: The determination module is used to determine, based on the target vibration location and the reference vibration field at the target vibration location, a set of reference mode participation coefficients corresponding to the intrinsic mode set associated with the vibration plate, and a set of reference mode participation coefficients to determine the target vibration field at the target vibration location. The selection module is used to select a subset of intrinsic modes for modal superposition from the intrinsic mode set, and determine the modal participation coefficient subset corresponding to the intrinsic mode subset, wherein the superimposed vibration field generated based on the intrinsic mode subset and its corresponding modal participation coefficient subset meets the preset similarity requirement with the target vibration field; as well as The drive control module is used to determine drive control information based on the subset of intrinsic modes and its corresponding subset of modal participation coefficients 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 apparatus of claim 10, wherein, Each intrinsic mode is associated with a corresponding resonant frequency, and the hardware configuration parameters of the vibrating plate are such that the frequency difference between the two resonant frequencies associated with every two adjacent intrinsic modes in the intrinsic mode set, sorted by the frequency value of the resonant frequency, is within the tactile sensitive frequency range.

12. The apparatus of claim 10, wherein, The target vibration location includes one or more target vibration locations. Wherein, the selection module is configured to select a subset of intrinsic modes for mode superposition from the intrinsic mode set as follows: From the set of intrinsic modes, candidate intrinsic modes for mode superposition are selected in increasing order in different iteration rounds as a subset of candidate intrinsic modes until the iteration termination condition is met. The iteration termination condition includes determining, based on the subset of intrinsic mode candidates and their corresponding modal participation coefficient subset selected in the latest iteration, that one or more superimposed vibration fields at one or more target vibration locations and the corresponding target vibration fields satisfy 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, which, when executed by the processor described above, can perform the method as described in any one of claims 1-9.

14. A system for generating localized vibrational tactile feedback, comprising: A vibrating plate, equipped with multiple vibration components; A laser vibration measurement device is used to measure the set of intrinsic modes associated with the vibrating plate. A processing device is configured to acquire a reference vibration field at the target vibration location and the intrinsic mode set obtained by the laser vibration measuring device, and to execute the method as described in claim 1; by and A drive circuit is used to generate and output a drive signal based on drive control information from the processing device to drive the plurality of vibration components, so that the plurality of vibration components drive the vibrating plate to vibrate.

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

16. The system of claim 14, wherein, The plurality of vibration components are multiple piezoelectric sheets disposed around the vibrating plate.

17. The system of claim 14, wherein, The hardware configuration parameters of the vibration plate ensure that the frequency difference between the two resonant frequencies associated with each two adjacent intrinsic modes in the intrinsic mode set, sorted by their resonant frequency values, is within the tactile sensitive frequency range.

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