Voice coil rubbing simulation method of vehicle-mounted sound production device, electronic equipment and storage medium

Abstract

The invention discloses a voice coil friction simulation method of a vehicle-mounted sound production device, electronic equipment and a storage medium. The voice coil friction simulation method of the vehicle-mounted sound production device comprises the following steps: establishing a finite element simulation model according to a geometric model of the vehicle-mounted sound production device, solving to obtain voice coil displacement, and judging whether a voice coil is in contact with a magnetic circuit and / or a frame of the vehicle-mounted sound production device; wherein when the finite element simulation model is established, a flow field simulation module is added, and grid division is carried out on an extracted flow field air domain; the flow field pressure of the vibrating diaphragm is obtained and serves as the boundary condition of the finite element simulation model. According to the invention, the voice coil rubbing problem can be directly judged, the time-consuming and labor-consuming problem that a later sample is subjected to rubbing and then returned to be modified is avoided, the risk can be controlled in the early-stage design, and the cost is saved.

Description

Technical Field

[0001] This invention relates to a method for simulating the rubbing of the voice coil in a vehicle-mounted sound device, an electronic device, and a storage medium. Background Technology

[0002] When a car audio system is operating, rubbing may occur between the speaker voice coil and the magnetic circuit, resulting in voice coil rubbing. This rubbing produces noticeable noise and, for subwoofers, diminishes their low-frequency characteristics, significantly reducing the user experience. This phenomenon is more pronounced in small-volume and irregularly shaped car subwoofers, as the small, irregular enclosure often leads to an imbalance in the pressure difference between the left and right sides of the diaphragm. If voice coil rubbing is not avoided in the early design phase, subsequent modifications to produce samples with rubbing are more time-consuming and labor-intensive, increasing product costs and lengthening the development cycle.

[0003] The information disclosed in the background section is only intended to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides a method for simulating voice coil rubbing in a vehicle-mounted sound device, an electronic device, and a storage medium. This method can directly identify voice coil rubbing problems, avoiding the time-consuming and laborious problem of having to go back and modify the sample when rubbing occurs later. It can control the risk in the early design stage and save costs.

[0005] The first aspect of the present invention provides a simulation method for voice coil rubbing of a vehicle-mounted sound device, comprising: establishing a finite element simulation model based on the geometric model of the vehicle-mounted sound device, solving for the voice coil displacement, and determining whether the voice coil is in contact with the magnetic circuit and / or frame of the vehicle-mounted sound device; In establishing the finite element simulation model, a flow field simulation module is added to mesh the extracted air flow field and obtain the flow field pressure of the diaphragm as the boundary condition of the finite element simulation model.

[0006] In some preferred embodiments, the geometric model is a simplified geometric model, which includes a cabinet and a speaker. The speaker is installed in the cabinet and includes a speaker diaphragm, a voice coil, and a magnetic circuit.

[0007] In some preferred embodiments, the speaker further includes a dust cap and / or a spider.

[0008] In some preferred embodiments, establishing the finite element simulation model includes a flow field simulation step, which includes: selecting a transient solver interface, setting the diaphragm as a velocity inlet, applying the maximum velocity of the diaphragm to the diaphragm, performing transient calculations, and obtaining the flow field pressure data of the diaphragm.

[0009] In some preferred embodiments, the maximum velocity of the diaphragm is calculated based on the target parameter signal of the vehicle-mounted sound generation device.

[0010] In some preferred embodiments, one or more cross sections of the diaphragm are taken, and the process pressure data includes the difference in flow field pressure applied to both sides of the cross section.

[0011] In some preferred embodiments, establishing the finite element simulation model includes a structural simulation step, which includes: selecting a steady-state solver interface, meshing the speaker's vibration system, using the diaphragm pressure data as boundary conditions, and adding the flow field pressure data to the diaphragm.

[0012] In some preferred embodiments, the loudspeaker's vibration system includes a diaphragm, a voice coil, a spider, and a magnetic circuit.

[0013] In some preferred embodiments, the finite element model is solved in a steady state to output a voice coil displacement contour map and determine whether the voice coil is in contact with the magnetic circuit.

[0014] A second aspect of the present invention provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the voice coil rubbing simulation method of the vehicle-mounted sound device.

[0015] A third aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the voice coil rubbing simulation method for the vehicle-mounted sound device.

[0016] The present invention adopts the above solution and has the following advantages: This invention provides a simulation method for voice coil rubbing in vehicle-mounted sound devices. Based on fluid-structure interaction (FSI) simulation, it can directly determine whether the voice coil rubs due to contact between the voice coil and the magnetic circuit / frame. This avoids the time-consuming and laborious process of returning to modify the sample after rubbing occurs, allowing for risk control in the early design phase and saving costs. Furthermore, the simulation is based on unidirectional FSI, primarily considering the influence of fluid pressure on the diaphragm, significantly reducing simulation difficulty and improving simulation efficiency. Attached Figure Description

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

[0018] Figure 1 This is a simulation flowchart of the voice coil rubbing motion of a vehicle-mounted sound generating device according to an embodiment of the present invention.

[0019] Figure 2 This is a geometric model of a vehicle-mounted sound-generating device to be simulated in an embodiment of the present invention.

[0020] Figure 3 This is a cross-sectional view of the geometric model according to an embodiment of the present invention.

[0021] Figure 4 This is a flow field simulation mesh according to an embodiment of the present invention.

[0022] Figure 5a and Figure 5b These are flow field pressure contour maps of two sections of the flow field simulation model at a certain moment.

[0023] Figure 6a and Figure 6b These are the pressure difference curves on both sides of two cross sections of the diaphragm.

[0024] Figure 7 This is a schematic diagram of a loudspeaker vibration system and fixed boundary according to an embodiment of the present invention.

[0025] Figure 8 This is a schematic diagram of a vibration system grid according to an embodiment of the present invention.

[0026] Figure 9a This is a voice coil displacement contour plot of a cross section of a finite element simulation model according to an embodiment of the present invention; Figure 9b for Figure 9a A magnified view of a specific part of the image.

[0027] Figure 10a This is a voice coil displacement contour plot of another section of the finite element simulation model according to an embodiment of the present invention; Figure 10b for Figure 10a A magnified view of a specific part of the image. Detailed Implementation

[0028] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more readily understood by those skilled in the art. It should be noted that the description of these embodiments is for the purpose of aiding understanding the present invention, but does not constitute a limitation thereof.

[0029] To address the voice coil and magnetic circuit rubbing issue in automotive audio devices (especially closed-box subwoofers), a unidirectional fluid-structure interaction (FSI) simulation method is proposed. This method obtains the maximum diaphragm velocity based on the speaker's target small parameter signal; processes the 3D geometric model and extracts the air computational domain; applies the velocity to the diaphragm portion within the air computational domain; calculates the diaphragm pressure in the flow field simulation module and exports the data; uses the exported pressure data as boundary conditions in the structural simulation module, ultimately obtaining a voice coil deformation contour map to determine if the voice coil rubs against the magnetic circuit. This method can directly identify voice coil rubbing issues, avoiding the time-consuming and labor-intensive process of reworking after sample rubbing occurs. It controls risks in the early design phase, significantly saving manpower and costs.

[0030] Reference Figure 1 As shown in the embodiment, a voice coil rubbing simulation method for an in-vehicle sound generator is used to determine whether the in-vehicle sound generator has a voice coil rubbing problem. The voice coil rubbing simulation method includes the following steps: The geometric structure was preprocessed using 3D software to simplify the model, and the air domain model was extracted to prepare for the next flow field simulation. The cleaned horn vibration system was then used as the model input for structural simulation. The maximum diaphragm velocity and its corresponding frequency are obtained by using the small parameter signal of the horn target. Add a flow field simulation module and select the transient solver interface; Watershed Grid: The entire watershed is divided into grids, and the grid needs to be refined near the diaphragm to obtain more accurate pressure contour maps; The velocity is applied to the diaphragm position in the air computation domain, the diaphragm pressure is calculated, and the data is exported. Vibration system structural grid: The entire vibration system is divided into grids, and the grid for the diaphragm needs to be refined to obtain a more accurate voice coil displacement contour map; Add a structural simulation module, select the steady-state solver, and use the exported pressure data as boundary conditions in the structural simulation module to finally obtain the voice coil contour plot.

[0031] For subwoofers, the primary consideration is the effect of fluid pressure on the diaphragm, with less concern for the effect of solid deformation on the fluid. Therefore, this embodiment uses a unidirectional fluid-structure interaction (FSI) method, which significantly reduces the simulation difficulty and improves simulation efficiency. It also effectively avoids the convergence problems that exist in direct two-way FSI simulations. Direct two-way FSI simulations suffer from some convergence issues, mainly due to the large solid deformation and low computational efficiency, resulting in poor convergence.

[0032] This embodiment specifically provides a method for simulating the voice coil friction of a vehicle-mounted closed-box subwoofer. (Refer to...) Figure 2 and Figure 3As shown, the vehicle-mounted subwoofer includes a housing 1 and a speaker 2. The housing 1 has an opening through which the speaker 2 is mounted on the housing 1, and the opening is closed by the diaphragm 22 of the speaker 2, thus forming a closed space inside the housing 1. This voice coil friction simulation method can also be applied to other types of vehicle-mounted sound devices, such as speakers with closed cavities, such as subwoofers.

[0033] The voice coil friction simulation method for this vehicle-mounted closed-box subwoofer includes the following steps: (1) 3D Model Simplification: Remove some minor features that affect mesh generation, such as components that are attached or connected to the diaphragm, folding ring, and dust cap. After simplification, the model is as follows: Figure 2 and Figure 3 As shown. The enclosure 1 and speaker 2 retain the core components such as the frame 21, diaphragm 22, dust cap 23, voice coil 24, magnetic circuit 25, and spider 26. Among them, the frame 21 of the speaker 2 is fixed to the enclosure 1, the diaphragm 22 is suspended on the frame 21, the voice coil 24 is connected to the diaphragm 22 and has one end that can be movably inserted into the magnetic gap of the magnetic circuit 25, and the spider 26 is fixed to the frame 21 and sleeved on the voice coil 24.

[0034] (2) The maximum diaphragm velocity is obtained from the speaker's target small parameter signal: The resonant frequency F0 of the subwoofer enclosure is 72 Hz, and the peak displacement X0 is 6 mm, obtained from the speaker's small parameters. Furthermore, the displacement curve formula of the speaker after AC power is known is: X = X0 × e^(jwt) V = X0 × w × e^(jwt) w=2×π×f Where X is the diaphragm displacement, V is the rated voltage, X0 is the peak displacement, w is the angular frequency, f is the test frequency, t is the time, and j is the imaginary unit.

[0035] The resonant frequency of 72 Hz and the rated voltage of 7.87 V were used to convert the values ​​into steady-state and transient velocities, which were then used as the unsteady-state inlet velocities, as shown in Table 1. The calculation time was 50 ms.

[0036] Table 1 Boundary Condition Settings

[0037] (3) Establish a flow field simulation model a. Add a flow field simulation module and select the transient solver interface.

[0038] b. Mesh the extracted airflow field and apply the maximum velocity to the diaphragm position and set it as the inlet.

[0039] See Figure 4As shown, the space inside the box is taken as the air domain of the flow field, and a mesh is generated. Figure 4 The flow field simulation mesh is shown below; Figure 4 The red area (diaphragm) serves as the velocity inlet. For the diaphragm and its vicinity, a finer mesh is needed to obtain a more accurate pressure contour map.

[0040] c. Click "Transient Calculation" to obtain and export the pressure data for diaphragm cross-sections 1 and 2. The exported pressure data represents the flow field pressure on both sides of the diaphragm cross-sections. Cross-sections 1 and 2 are preferably two mutually perpendicular planes to obtain pressure data for all parts of the diaphragm as comprehensively as possible.

[0041] Figure 5a The pressure contour plot of the flow field at section 1 at a certain moment (0.044s) is shown. Figure 5b The flow field pressure contour map of section 2 at a certain moment (0.044s) is shown.

[0042] Figure 6a The pressure difference curves on both sides of diaphragm section 1 are shown. Figure 6b The pressure difference curves on both sides of diaphragm section 2 are shown. Section 1 is... Figure 6a The pressure difference (ΔP) at the interface between the pink and blue areas in the upper right corner is the pressure difference between the pink and blue areas (P). red - P blue Section 2 is Figure 6b The interface between the pink and blue parts in the upper right corner.

[0043] (4) Establish a structural simulation model Add a structural simulation module and select the steady-state solver interface; Import the simplified 3D model into "Geometry" and add the exported pressure data to both sides of the diaphragm cross section to form a composite. Set the material parameters for each component, including Young's modulus, Poisson's ratio, and density; right Figure 7 The vibration system is meshed, such as... Figure 8 As shown; Submit the calculation.

[0044] The loudspeaker's vibration system includes a diaphragm, voice coil, and magnetic circuit. In this embodiment, the loudspeaker also includes a dust cap and a spider, thus the dust cap and spider are also included in the vibration system. The diaphragm requires a denser mesh, such as... Figure 8 As shown.

[0045] (5) Structural module solution and post-processing In the results, click "3D Plotting Group", then right-click to add a volume (select the volume you want to study).

[0046] To generate the maximum displacement of the volume, select the maximum displacement value of the volume under the derived values ​​in the results, choose solid.disp, export the voice coil displacement contour map, find the point with the maximum displacement, and determine whether the voice coil and magnetic circuit are rubbing against each other.

[0047] Figure 9a and Figure 9b The voice coil displacement contour plot of section 1 is shown. Figure 10a and Figure 10b The voice coil displacement contour plot for section 2 is shown. As can be seen from the plot, no part of the voice coil is in contact with the magnetic circuit. Therefore, the 3D geometric model and parameters of the vehicle-mounted generator under study do not exhibit voice coil rubbing issues, and prototype production can proceed. However, if the exported voice coil displacement contour plot shows contact or interference between the voice coil and the magnetic circuit, then a voice coil rubbing issue exists. In this case, the 3D geometric model or its parameters need to be modified, and the simulation process repeated until the voice coil rubbing issue is eliminated.

[0048] In this embodiment, since the distance between the frame and the voice coil in the speaker structure is relatively large, the only component causing the voice coil to rub against the coil is the magnetic circuit. Therefore, only the displacement change between the magnetic circuit and the voice coil is considered. However, in some other embodiments, if the distance between the frame and the voice coil is relatively small, it may be necessary to consider the displacement change between the frame and the voice coil, and whether there is any phenomenon of the frame and the voice coil touching each other.

[0049] As indicated in this specification and claims, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, and these steps and elements do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0050] It can be further understood that in this disclosure, "multiple" refers to two or more, and other quantifiers are similar.

[0051] It is further understood that the terms "first," "second," etc., are used to describe various types of information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another, and do not indicate a specific order or degree of importance. In fact, the expressions "first," "second," etc., are completely interchangeable. For example, without departing from the scope of this disclosure, first information can also be referred to as second information, and similarly, second information can also be referred to as first information.

[0052] The above embodiments are only for illustrating the technical concept and features of the present invention, and are preferred embodiments. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention.

Claims

1. A method for simulating the rubbing of a voice coil in a vehicle-mounted sound-generating device, characterized in that, include: A finite element simulation model is established based on the geometric model of the vehicle-mounted sound generator, the voice coil displacement is obtained by solving the problem, and it is determined whether the voice coil is in contact with the magnetic circuit and / or frame of the vehicle-mounted sound generator. In the process of establishing the finite element simulation model, a flow field simulation module is added to perform mesh generation on the extracted air domain of the flow field. The flow field pressure of the diaphragm is obtained and used as the boundary condition of the finite element simulation model.

2. The voice coil friction simulation method according to claim 1, characterized in that, The geometric model is a simplified geometric model, which includes a cabinet and a speaker. The speaker is installed in the cabinet and includes a speaker diaphragm, voice coil and magnetic circuit.

3. The voice coil friction simulation method according to claim 2, characterized in that, The speaker also includes a dust cap and / or a spring.

4. The voice coil friction simulation method according to claim 1, characterized in that, The establishment of the finite element simulation model includes a flow field simulation step, which includes: selecting the transient solver interface, setting the diaphragm as the velocity inlet, applying the maximum velocity of the diaphragm to the diaphragm, performing transient calculations, and obtaining the flow field pressure data of the diaphragm.

5. The voice coil friction simulation method according to claim 4, characterized in that, The maximum velocity of the diaphragm is calculated based on the target parameter signal of the vehicle-mounted sound generator. One or more cross sections of the diaphragm are taken, and the process pressure data includes the difference in flow field pressure applied to both sides of the cross section.

6. The voice coil friction simulation method according to claim 1, characterized in that, The establishment of the finite element simulation model includes a structural simulation step, which includes: selecting a steady-state solver interface, meshing the speaker's vibration system, using the diaphragm pressure data as boundary conditions, and adding the flow field pressure data to the diaphragm.

7. The voice coil friction simulation method according to claim 6, characterized in that, The vibration system of a loudspeaker includes a diaphragm, voice coil, spider, and magnetic circuit.

8. The voice coil friction simulation method according to claim 1, characterized in that, The finite element model is solved in steady state, and the voice coil displacement contour map is output to determine whether the voice coil is in contact with the magnetic circuit.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the voice coil rubbing simulation method for the vehicle-mounted sound device as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the voice coil rubbing simulation method for an in-vehicle sound-generating device as described in any one of claims 1 to 8.

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