A design method, system, terminal and storage medium for low-speed pedestrian warning sound of electric vehicle

Abstract

The present invention discloses a design method, system, terminal and storage medium for low-speed pedestrian warning sound of electric vehicles, belonging to the technical field of warning sound system of electric vehicles, including: respectively obtaining the frequency response characteristic curve of white noise signal, the frequency response characteristic curve at the plane of pedestrian warning speaker, the frequency response characteristic curve at the plane of sound source speaker and the frequency response characteristic curve at the front end of sound source speaker vehicle; obtaining comprehensive transfer function; obtaining subjective output sound source material, obtaining subjective input sound source through the subjective output sound source material and comprehensive transfer function; obtaining corrected version input sound source through the subjective input sound source and comprehensive transfer function. This patent compensates for the sound pressure level and spectrum changes in advance through the design of sound source, thereby solving the problem of distortion of warning sound heard by pedestrians.

Description

Technical Field

[0001] The invention discloses a design method, system, terminal and storage medium for a low-speed pedestrian warning sound of an electric vehicle, and belongs to the technical field of warning sound systems of electric vehicles. Background Art

[0002] The sound principle of the low-speed pedestrian warning sound is that the sound source signal A is amplified by the power amplifier system and the sound B is emitted from the speaker. The sound B is then transmitted to the outside of the vehicle through the engine cover, floor, front bumper grille and other parts at the front of the vehicle, so that pedestrians outside the vehicle can hear the sound C, thereby warning pedestrians outside the vehicle.

[0003] Because the power amplifier-speaker system has certain frequency response characteristics, and after the sound is emitted from the speaker, it must pass through a series of parts before it can be transmitted outside the car, both systems will affect the spectrum and sound pressure level of the sound source, causing the sound heard by pedestrians to be distorted compared to the original sound source, affecting the sound quality and the pedestrian's auditory experience.

[0004] The main reason that affects the sound quality and the auditory experience of pedestrians is that the sound will be distorted due to the influence of the transfer function during the outward propagation process. The existing technologies have focused on improving the sound quality and sound control strategies, but have not mentioned how to change the distortion of the sound source to make it sound fuller. Summary of the invention

[0005] In view of the defects of the prior art, the present invention proposes a design method, system, terminal and storage medium for a low-speed pedestrian warning sound of an electric vehicle. By designing the sound source, the sound pressure level and spectrum changes are compensated in advance, thereby solving the problem of distortion of the warning sound heard by pedestrians.

[0006] The technical solution of the present invention is as follows:

[0007] According to a first aspect of an embodiment of the present invention, a method for designing a low-speed pedestrian warning sound for an electric vehicle is provided, comprising:

[0008] Respectively obtain a frequency response characteristic curve of a white noise signal, a frequency response characteristic curve at a plane of a pedestrian warning speaker, a frequency response characteristic curve at a plane of a sound source speaker, and a frequency response characteristic curve at a front end of a vehicle of a sound source speaker;

[0009] Obtaining a comprehensive transfer function through the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker, and the frequency response characteristic curve at the front end of the sound source speaker;

[0010] Obtaining subjective output sound source material, and obtaining a subjective input sound source through the subjective output sound source material and a comprehensive transfer function;

[0011] A corrected version of the input sound source is obtained through the subjective input sound source and the comprehensive transfer function.

[0012] Preferably, it also includes:

[0013] The frequency response characteristic curve of the pedestrian warning speaker at the front end of the vehicle is obtained through the corrected input sound source, and the revised input sound source is obtained through the frequency response characteristic curve of the pedestrian warning speaker at the front end of the vehicle and the subjective output sound source material.

[0014] Preferably, the step of obtaining the subjective output sound source material and obtaining the subjective input sound source through the subjective output sound source material and the comprehensive transfer function includes:

[0015] Obtain subjective output sound source material;

[0016] Obtaining a subjective output sound source material frequency response characteristic function through the subjective output sound source material;

[0017] The subjective input sound source is obtained through the subjective output sound source material frequency response characteristic function and the comprehensive transfer function.

[0018] Preferably, obtaining a corrected version of the input sound source through the subjective input sound source and the comprehensive transfer function comprises:

[0019] Obtaining a corrected version of the output sound source material through the subjective input sound source and the subjective output sound source material;

[0020] The corrected version of the input sound source is obtained through the corrected version of the output sound source material and the comprehensive transfer function.

[0021] Preferably, the comprehensive transfer function obtained by the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker and the frequency response characteristic curve at the front end of the sound source speaker vehicle comprises:

[0022] The frequency response characteristic function of the white noise signal, the frequency response characteristic function at the plane of the pedestrian warning speaker, the frequency response characteristic function at the plane of the sound source speaker and the frequency response characteristic curve at the front end of the sound source speaker are obtained respectively through the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker and the frequency response characteristic curve at the front end of the sound source speaker;

[0023] The comprehensive transfer function is obtained by using the frequency response characteristic function of the white noise signal, the frequency response characteristic function at the plane of the pedestrian warning speaker, the frequency response characteristic function at the plane of the sound source speaker, and the frequency response characteristic function at the front end of the sound source speaker through formula (1):

[0024]

[0025] Among them: B is the frequency response characteristic function of the pedestrian warning speaker plane, A0 is the frequency response characteristic function of the white noise signal, E is the frequency response characteristic function of the sound source speaker at the front end of the vehicle, D is the frequency response characteristic function of the sound source speaker plane, and Y is the comprehensive transfer function.

[0026] Preferably, obtaining the subjective output sound source material frequency response characteristic function through the subjective output sound source material includes:

[0027] Obtaining a subjective output sound source material frequency response characteristic curve through the subjective output sound source material;

[0028] Obtaining a subjective output sound source material frequency response characteristic function through a subjective output sound source material frequency response characteristic curve;

[0029] The subjective input sound source function is obtained by using the subjective output sound source material frequency response characteristic function and the comprehensive transfer function through formula (2):

[0030]

[0031] Among them, G is the subjective input sound source function, and F is the subjective output sound source material frequency response characteristic function;

[0032] The subjective input sound source is obtained through the subjective input sound source function.

[0033] Preferably, the step of obtaining the corrected version of the input sound source by using the corrected version of the output sound source material and the integrated transfer function comprises:

[0034] Obtaining a frequency response characteristic curve of a calibrated version output sound source material by using the calibrated version output sound source material;

[0035] The frequency response characteristic function of the corrected version output sound source material is obtained through the frequency response characteristic curve of the corrected version output sound source material;

[0036] Obtaining a corrected version of the input sound source function through the corrected version of the output sound source material frequency response characteristic function and the comprehensive transfer function;

[0037] The corrected version of the input sound source is obtained through the corrected version of the input sound source function.

[0038] According to a second aspect of an embodiment of the present invention, a low-speed pedestrian warning sound design system for an electric vehicle is provided, the design system comprising:

[0039] An acquisition module, used to respectively acquire a frequency response characteristic curve of a white noise signal, a frequency response characteristic curve at a plane of a pedestrian warning speaker, a frequency response characteristic curve at a plane of a sound source speaker, and a frequency response characteristic curve at a front end of a vehicle of a sound source speaker;

[0040] A fitting module, for obtaining a comprehensive transfer function through the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker, and the frequency response characteristic curve at the front end of the sound source speaker;

[0041] The analysis module is used to obtain subjective output sound source material, and obtain the subjective input sound source through the subjective output sound source material and the comprehensive transfer function.

[0042] The correction module is used to obtain a corrected version of the input sound source through the subjective input sound source and the comprehensive transfer function.

[0043] According to a third aspect of an embodiment of the present invention, a terminal is provided, including:

[0044] one or more processors;

[0045] a memory for storing the one or more processor-executable instructions;

[0046] Wherein, the one or more processors are configured to:

[0047] Execute the method described in the first aspect of the embodiment of the present invention.

[0048] According to a fourth aspect of an embodiment of the present invention, a non-temporary computer-readable storage medium is provided. When instructions in the storage medium are executed by a processor of a terminal, the terminal is enabled to execute the method described in the first aspect of the embodiment of the present invention.

[0049] According to a fifth aspect of an embodiment of the present invention, an application product is provided. When the application product is running on a terminal, the terminal executes the method described in the first aspect of the embodiment of the present invention.

[0050] The beneficial effects of the present invention are:

[0051] This patent provides a design method, system, terminal and storage medium for a low-speed pedestrian warning sound of an electric vehicle. By measuring the frequency response characteristics of the low-speed pedestrian warning sound system of an electric vehicle and the transfer function on its transmission path, the sound pressure level and spectrum changes of the low-speed pedestrian warning sound can be predicted in advance. Therefore, by designing the sound source, the sound pressure level and spectrum changes can be compensated in advance, thereby solving the problem of distortion of the warning sound heard by pedestrians.

[0052] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 is a flow chart of a method for designing a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0054] Figure 2 is a flow chart of a method for designing a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0055] Figure 3 It is a schematic diagram of the measurement arrangement of a pedestrian warning speaker in a design method for a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0056] Figure 4 is a frequency response characteristic curve diagram of a white noise signal in a design method for a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0057] Figure 5 is a frequency response characteristic curve at the plane of a pedestrian warning speaker in a design method for a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0058] Figure 6 It is a schematic diagram of the measurement arrangement of a sound source speaker in a design method for a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0059] Figure 7 is a frequency response characteristic curve at a plane of a sound source speaker in a design method for a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0060] Figure 8 is a frequency response characteristic curve of a sound source speaker at the front end of a vehicle in a design method for a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0061] Fig. 9 It is a comprehensive transfer function curve in a design method of a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0062] Fig.10It is a frequency response characteristic curve of a subjective output sound source material in a design method for a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0063] Fig.11 It is a frequency response characteristic curve of a corrected version of an output sound source material in a design method for a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0064] Fig.12 It is a frequency response characteristic curve of a corrected version of an input sound source in a design method for a low-speed pedestrian warning sound for an electric vehicle according to an exemplary embodiment;

[0065] Fig.13 It is a structural schematic block diagram of a low-speed pedestrian warning sound design system for electric vehicles according to an exemplary embodiment;

[0066] Fig.14 The present invention is a schematic block diagram of a terminal structure according to an exemplary embodiment. DETAILED DESCRIPTION

[0067] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0068] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0069] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] An embodiment of the present invention provides a method for designing a low-speed pedestrian warning sound for an electric vehicle. The method is implemented by a terminal, which may be a smart phone, a desktop computer, or a laptop computer, etc. The terminal at least includes a CPU, a voice collection device, etc.

[0071] Embodiment 1

[0072] Figure 1 The present invention is a flow chart of a method for designing a low-speed pedestrian warning tone for an electric vehicle according to an exemplary embodiment. The method is used in a terminal and comprises the following steps:

[0073] Step 101, respectively obtaining a frequency response characteristic curve of a white noise signal, a frequency response characteristic curve at a plane of a pedestrian warning speaker, a frequency response characteristic curve at a plane of a sound source speaker, and a frequency response characteristic curve at a front end of a vehicle of a sound source speaker;

[0074] Step 102, obtaining a comprehensive transfer function through the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker, and the frequency response characteristic curve at the front end of the sound source speaker;

[0075] Step 103: Obtain subjective output sound source material, and obtain a subjective input sound source through the subjective output sound source material and a comprehensive transfer function;

[0076] Step 104: Obtain a corrected version of the input sound source through the subjective input sound source and the integrated transfer function.

[0077] Preferably, it also includes:

[0078] The frequency response characteristic curve of the pedestrian warning speaker at the front end of the vehicle is obtained through the corrected input sound source, and the revised input sound source is obtained through the frequency response characteristic curve of the pedestrian warning speaker at the front end of the vehicle and the subjective output sound source material.

[0079] Preferably, the step of obtaining the subjective output sound source material and obtaining the subjective input sound source through the subjective output sound source material and the comprehensive transfer function includes:

[0080] Obtain subjective output sound source material;

[0081] Obtaining a subjective output sound source material frequency response characteristic function through the subjective output sound source material;

[0082] The subjective input sound source is obtained through the subjective output sound source material frequency response characteristic function and the comprehensive transfer function.

[0083] Preferably, obtaining a corrected version of the input sound source through the subjective input sound source and the comprehensive transfer function comprises:

[0084] Obtaining a corrected version of the output sound source material through the subjective input sound source and the subjective output sound source material;

[0085] The corrected version of the input sound source is obtained through the corrected version of the output sound source material and the comprehensive transfer function.

[0086] Preferably, the comprehensive transfer function obtained by the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker and the frequency response characteristic curve at the front end of the sound source speaker vehicle comprises:

[0087] The frequency response characteristic function of the white noise signal, the frequency response characteristic function at the plane of the pedestrian warning speaker, the frequency response characteristic function at the plane of the sound source speaker and the frequency response characteristic curve at the front end of the sound source speaker are obtained respectively through the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker and the frequency response characteristic curve at the front end of the sound source speaker;

[0088] The comprehensive transfer function is obtained by using the frequency response characteristic function of the white noise signal, the frequency response characteristic function at the plane of the pedestrian warning speaker, the frequency response characteristic function at the plane of the sound source speaker, and the frequency response characteristic function at the front end of the sound source speaker through formula (1):

[0089]

[0090] Among them: B is the frequency response characteristic function of the pedestrian warning speaker plane, A0 is the frequency response characteristic function of the white noise signal, E is the frequency response characteristic function of the sound source speaker at the front end of the vehicle, D is the frequency response characteristic function of the sound source speaker plane, and Y is the comprehensive transfer function.

[0091] Preferably, obtaining the subjective output sound source material frequency response characteristic function through the subjective output sound source material includes:

[0092] Obtaining a subjective output sound source material frequency response characteristic curve through the subjective output sound source material;

[0093] Obtaining a subjective output sound source material frequency response characteristic function through a subjective output sound source material frequency response characteristic curve;

[0094] The subjective input sound source function is obtained by using the subjective output sound source material frequency response characteristic function and the comprehensive transfer function through formula (2):

[0095]

[0096] Among them, G is the subjective input sound source function, and F is the subjective output sound source material frequency response characteristic function;

[0097] The subjective input sound source is obtained through the subjective input sound source function.

[0098] Preferably, the step of obtaining the corrected version of the input sound source by using the corrected version of the output sound source material and the integrated transfer function comprises:

[0099] Obtaining a frequency response characteristic curve of a calibrated version output sound source material by using the calibrated version output sound source material;

[0100] The frequency response characteristic function of the corrected version output sound source material is obtained through the frequency response characteristic curve of the corrected version output sound source material;

[0101] Obtaining a corrected version of the input sound source function through the corrected version of the output sound source material frequency response characteristic function and the comprehensive transfer function;

[0102] The corrected version of the input sound source is obtained through the corrected version of the input sound source function.

[0103] Embodiment 2

[0104] Figure 2 The present invention is a flow chart of a method for designing a low-speed pedestrian warning sound for an electric vehicle based on a system transfer function according to an exemplary embodiment. The method is used in a terminal and includes the following steps:

[0105] Step 201, respectively obtaining a frequency response characteristic curve of a white noise signal and a frequency response characteristic curve at a plane of a pedestrian warning speaker;

[0106] like Figure 3 As shown, in the full anechoic room, fix the pedestrian warning device on the baffle. The size of the baffle meets the GB / T12060.5 sound system equipment, so that the axis direction of the speaker is parallel to the ground. Fix a microphone on the front axis of the speaker 1m away from the center plane diaphragm of the speaker. Connect the microphone to the test front end, and set the front end analysis frequency bandwidth to 20480Hz. Use the calibration equipment to calibrate the microphone. Input the white noise signal into the pedestrian warning device storage unit, and obtain the frequency response characteristic curve of the white noise from the network, as shown in Figure 4 As shown, the horizontal axis of the coordinate axis is frequency, and the vertical axis is sound pressure. The signal uses a simulator to simulate a vehicle speed of 1km / h, drives the pedestrian warning device to emit a pedestrian warning sound, and measures and records the effective value of the pedestrian warning device input voltage.

[0107] Start the equipment to collect sound for 20 seconds. Repeat the measurement at least 3 times for each test, take the average value of the results, perform FFT frequency domain analysis on the data, with a frequency resolution of 2Hz, and obtain the frequency response characteristic curve of the pedestrian warning speaker at the measuring point. Because the geometric size of the pedestrian warning device is much smaller than the distance from the center of the sound source to the measuring point, the pedestrian warning device can be considered as a point sound source. If the frequency response characteristic curve at the measuring point is known, the attenuation value of the point sound source with increasing distance can be obtained according to formula (1). The frequency response characteristic curve of the pedestrian warning speaker at the plane can be inferred from the attenuation value of the point sound source with increasing distance, as shown in the figure: Figure 5 shown.

[0108]

[0109] Where:

[0110] AdiV = the attenuation of a point sound source as distance increases, in dB.

[0111] r1, r2 are the distances from the point sound source, in meters. Let r1 = 1, r2 = 0.01.

[0112] Step 202: Obtain a frequency response characteristic curve of the sound source speaker at the plane.

[0113] like Figure 6 As shown, a loudspeaker with an effective frequency range of 200-5000Hz is selected as the sound source. In a fully anechoic room, fix the loudspeaker on a baffle (the size of the baffle meets GB / T 12060.5 Sound System Equipment Part 5: Test Method for Main Performance of Loudspeakers) so that the axis of the loudspeaker is parallel to the ground. Fix a microphone on the front axis of the loudspeaker 1m away from the center plane diaphragm of the loudspeaker. Connect the microphone to the test front end, and set the front-end analysis frequency bandwidth to 20480Hz. Use the calibration equipment to calibrate the microphone. Input a white noise signal into the loudspeaker to drive the loudspeaker to sound, adjust the signal voltage so that the total sound pressure level at the measuring point is the same as the total sound pressure level measured in step 202, measure the effective value of the input voltage and record it.

[0114] Start the device to collect sound for 20 seconds. Repeat the measurement at least 3 times for each test and take the average value. Perform FFT frequency domain analysis on the data with a frequency resolution of 2Hz to obtain the frequency response characteristic curve of the sound source speaker test point. Because the geometric size of the speaker is much smaller than the distance from the center of the sound source to the measurement point, the speaker can be considered as a point sound source. According to the same steps as formula 1 in step 202, the frequency response characteristic curve of the sound source speaker plane can be inferred, such as Figure 7 shown.

[0115] Step 203: Obtain a frequency response characteristic curve of the sound source speaker at the front end of the vehicle.

[0116] Embed the sound source speaker into the box to isolate its front and rear diaphragms. Place the test vehicle in the semi-anechoic chamber of the whole vehicle, with the front end of the vehicle greater than 3m away from the sharp wall of the anechoic chamber. Install a sound source speaker with a box at the original installation position of the pedestrian warning device at the front end of the vehicle, and point the speaker in the same direction as the warning speaker. Install a microphone at the designated measuring point outside the vehicle, and connect the microphone to the test front end. The analysis frequency bandwidth of the test front end is set to 20480Hz. Use the calibration equipment to calibrate the microphone. Use a white noise signal as the excitation signal of the speaker, and adjust the voltage so that the voltage across the speaker is consistent with that in step 203.

[0117] Start the equipment to collect sound for 20 seconds. Repeat the measurement for no less than 3 times for each test. Take the average value of the result. Perform FFT frequency domain analysis on the data with a frequency resolution of 2Hz to obtain the frequency response characteristic curve of the sound source speaker at the front end of the vehicle, as shown in the figure. Figure 8 shown.

[0118] Step 204 , obtaining a comprehensive transfer function through the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker, and the frequency response characteristic curve at the front end of the sound source speaker.

[0119] The frequency response characteristic function of the white noise signal, the frequency response characteristic function at the plane of the pedestrian warning speaker, the frequency response characteristic function at the plane of the sound source speaker and the frequency response characteristic curve at the front end of the sound source speaker are obtained respectively through the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker and the frequency response characteristic curve at the front end of the sound source speaker;

[0120] The comprehensive transfer function is obtained by using the frequency response characteristic function of the white noise signal, the frequency response characteristic function at the plane of the pedestrian warning speaker, the frequency response characteristic function at the plane of the sound source speaker, and the frequency response characteristic function at the front end of the sound source speaker through formula (2):

[0121]

[0122] Among them: B is the frequency response characteristic function of the pedestrian warning speaker plane, A0 is the frequency response characteristic function of the white noise signal, E is the frequency response characteristic function of the sound source speaker at the front end of the vehicle, D is the frequency response characteristic function of the sound source speaker plane, and Y is the comprehensive transfer function.

[0123] The comprehensive transfer function curve is obtained through the comprehensive transfer function, such as Fig. 9 shown.

[0124] Step 205: Obtain subjective output sound source material, and obtain a frequency response characteristic function of the subjective output sound source material through the subjective output sound source material.

[0125] Organize a subjective evaluation team to conduct subjective evaluation on a given number of sound samples. In the sound subjective evaluation laboratory, use audio high-fidelity playback equipment to play back several given groups of pedestrian warning sound samples, and team members will conduct subjective evaluation on the sound. Score the evaluated sound materials according to the pleasantness of the sound. Finally, calculate the average score of each sound material, and select the sound material with the highest average score as the subjective output sound source material.

[0126] The subjective output sound source material selected by subjective evaluation is used as the output signal, and FFT frequency domain analysis is performed on it with a frequency resolution of 2Hz to obtain the frequency response characteristic curve of the subjective output sound source material, such as Fig.10 As shown, the subjective output sound source material frequency response characteristic function is obtained through the subjective output sound source material frequency response characteristic curve.

[0127] Step 206, obtaining a subjective input sound source through the subjective output sound source material frequency response characteristic function and the comprehensive transfer function;

[0128] The subjective input sound source function is obtained by using the subjective output sound source material frequency response characteristic function and the comprehensive transfer function through formula (3):

[0129]

[0130] Among them, G is the subjective input sound source function, and F is the subjective output sound source material frequency response characteristic function;

[0131] The subjective input sound source is obtained through the subjective input sound source function.

[0132] Step 207: Obtain a corrected version of the input sound source through the subjective input sound source and the integrated transfer function.

[0133] The subjective input sound source is used as the target sound source, and the subjective output sound source material is corrected and edited using sound editing software to make its spectrum and sound pressure level consistent with the subjective input sound source, thereby obtaining the corrected version of the output sound source material. The corrected version of the output sound source material frequency response characteristic curve is obtained through the corrected version of the output sound source material, such as Fig.11 As shown; the corrected version output sound source material frequency response characteristic curve is used to obtain the corrected version output sound source material frequency response characteristic function, and the corrected version input sound source function is obtained by the corrected version output sound source material frequency response characteristic function and the comprehensive transfer function through formula (3), and the corrected version input sound source frequency response characteristic curve of the corrected version input sound source function is as follows: Fig.12 As shown, the corrected version of the input sound source is obtained through the corrected version of the input sound source function.

[0134] Step 208: Obtain a revised version of the input sound source through the corrected version of the input sound source and the subjective output sound source material.

[0135] The frequency response characteristic curve of the pedestrian warning speaker of the corrected version input sound source at the front end of the vehicle is obtained by using the corrected version input sound source, and the specific contents are as follows:

[0136] The modified input signal G is stored in the pedestrian warning device assembly, which is driven to sound, and the sound is tested at a fixed measurement point outside the vehicle. The frequency bandwidth of the front-end analysis of the test is set to 20480Hz, and the acquisition time is 20s. Each test is repeated for no less than 3 times, and the results are averaged. The data is analyzed by FFT frequency domain with a frequency resolution of 2Hz to obtain the frequency response characteristic curve of the corrected version of the input sound source pedestrian warning speaker at the front end of the vehicle.

[0137] The corrected version of the input sound source is obtained by combining the frequency response characteristic curve of the pedestrian warning speaker at the front end of the vehicle with the subjective output sound source material. The specific contents are as follows:

[0138] The frequency response characteristic curve of the corrected version of the input sound source pedestrian warning speaker at the front of the vehicle obtained by the test is compared with the frequency response characteristic curve of the subjective output sound source material, and the difference frequency points and amplitudes of the two curves are compared. According to the comparison results, the target sound source is fine-tuned using sound software until the difference between the two curves meets the requirements, and the subjective output sound source material is obtained by fine-tuning to obtain the corrected version of the input sound source.

[0139] The present invention can predict the sound pressure level and spectrum changes of the low-speed pedestrian warning sound in advance by measuring the frequency response characteristics of the low-speed pedestrian warning sound system of the electric vehicle and the transfer function on its transmission path. Therefore, by designing the sound source, the sound pressure level and spectrum changes can be compensated in advance, thereby solving the problem of distortion of the warning sound heard by pedestrians.

[0140] In an exemplary embodiment, a low-speed pedestrian warning sound design system for an electric vehicle is also provided. Fig.13 As shown, the design system includes:

[0141] An acquisition module 310 is used to respectively acquire a frequency response characteristic curve of a white noise signal, a frequency response characteristic curve at a plane of a pedestrian warning speaker, a frequency response characteristic curve at a plane of a sound source speaker, and a frequency response characteristic curve at a front end of a vehicle of a sound source speaker;

[0142] A fitting module 320 is configured to obtain a comprehensive transfer function through the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker, and the frequency response characteristic curve at the front end of the sound source speaker.

[0143] The analysis module 330 is used to obtain subjective output sound source material, and obtain the subjective input sound source through the subjective output sound source material and the comprehensive transfer function.

[0144] The correction module 340 is used to obtain a corrected version of the input sound source through the subjective input sound source and the integrated transfer function.

[0145] The present invention can predict the sound pressure level and spectrum changes of the low-speed pedestrian warning sound in advance by measuring the frequency response characteristics of the low-speed pedestrian warning sound system of the electric vehicle and the transfer function on its transmission path. Therefore, by designing the sound source, the sound pressure level and spectrum changes can be compensated in advance, thereby solving the problem of distortion of the warning sound heard by pedestrians.

[0146] Embodiment 4

[0147] Fig.14 400 is a block diagram of a terminal provided in an embodiment of the present application, and the terminal may be a terminal in the above embodiment. The terminal 400 may be a portable mobile terminal, such as a smart phone or a tablet computer. The terminal 400 may also be referred to as a user equipment, a portable terminal, or other names.

[0148] Typically, the terminal 400 includes a processor 401 and a memory 402 .

[0149] The processor 401 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 401 may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). The processor 401 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 401 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 401 may also include an AI (Artificial Intelligence) processor, which is used to process computing operations related to machine learning.

[0150] The memory 402 may include one or more computer-readable storage media, which may be tangible and non-transitory. The memory 402 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In some embodiments, the non-transitory computer-readable storage medium in the memory 402 is used to store at least one instruction, which is used to be executed by the processor 401 to implement a low-speed pedestrian warning sound design system for electric vehicles provided in this application.

[0151] In some embodiments, the terminal 400 may further include: a peripheral device interface 403 and at least one peripheral device. Specifically, the peripheral device includes: at least one of a radio frequency circuit 404 , a touch screen 405 , a camera 406 , an audio circuit 407 , a positioning component 408 and a power supply 409 .

[0152] The peripheral device interface 403 may be used to connect at least one peripheral device related to I / O (Input / Output) to the processor 401 and the memory 402. In some embodiments, the processor 401, the memory 402, and the peripheral device interface 403 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 401, the memory 402, and the peripheral device interface 403 may be implemented on a separate chip or circuit board, which is not limited in this embodiment.

[0153] The radio frequency circuit 404 is used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The radio frequency circuit 404 communicates with the communication network and other communication devices through electromagnetic signals. The radio frequency circuit 404 converts the electrical signal into an electromagnetic signal for transmission, or converts the received electromagnetic signal into an electrical signal. Optionally, the radio frequency circuit 404 includes: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a user identity module card, etc. The radio frequency circuit 404 can communicate with other terminals through at least one wireless communication protocol. The wireless communication protocol includes but is not limited to: the World Wide Web, a metropolitan area network, an intranet, various generations of mobile communication networks (2G, 3G, 4G and 5G), a wireless local area network and / or a WiFi (Wireless Fidelity) network. In some embodiments, the radio frequency circuit 404 may also include circuits related to NFC (Near Field Communication), which is not limited in this application.

[0154] The touch display screen 405 is used to display the UI (User Interface). The UI may include graphics, text, icons, videos and any combination thereof. The touch display screen 405 also has the ability to collect touch signals on the surface or above the surface of the touch display screen 405. The touch signal can be input to the processor 401 as a control signal for processing. The touch display screen 405 is used to provide virtual buttons and / or virtual keyboards, also known as soft buttons and / or soft keyboards. In some embodiments, the touch display screen 405 can be one, and the front panel of the terminal 400 is set; in other embodiments, the touch display screen 405 can be at least two, which are respectively set on different surfaces of the terminal 400 or are folded; in some other embodiments, the touch display screen 405 can be a flexible display screen, which is set on the curved surface or folded surface of the terminal 400. Even, the touch display screen 405 can also be set to a non-rectangular irregular shape, that is, a special-shaped screen. The touch display screen 405 can be made of materials such as LCD (Liquid Crystal Display), OLED (Organic Light-Emitting Diode, organic light-emitting diode).

[0155] The camera assembly 406 is used to capture images or videos. Optionally, the camera assembly 406 includes a front camera and a rear camera. Typically, the front camera is used to realize video calls or selfies, and the rear camera is used to realize the shooting of photos or videos. In some embodiments, there are at least two rear cameras, which are any one of a main camera, a depth of field camera, and a wide-angle camera, so as to realize the fusion of the main camera and the depth of field camera to realize the background blur function, and the fusion of the main camera and the wide-angle camera to realize panoramic shooting and VR (Virtual Reality) shooting functions. In some embodiments, the camera assembly 406 may also include a flash. The flash can be a monochrome temperature flash or a dual-color temperature flash. A dual-color temperature flash refers to a combination of a warm light flash and a cold light flash, which can be used for light compensation at different color temperatures.

[0156] The audio circuit 407 is used to provide an audio interface between the user and the terminal 400. The audio circuit 407 may include a microphone and a speaker. The microphone is used to collect sound waves from the user and the environment, and convert the sound waves into electrical signals and input them into the processor 401 for processing, or input them into the radio frequency circuit 404 to achieve voice communication. For the purpose of stereo acquisition or noise reduction, there may be multiple microphones, which are respectively arranged at different parts of the terminal 400. The microphone may also be an array microphone or an omnidirectional acquisition microphone. The speaker is used to convert the electrical signal from the processor 401 or the radio frequency circuit 404 into sound waves. The speaker may be a traditional film speaker or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, it can not only convert the electrical signal into sound waves audible to humans, but also convert the electrical signal into sound waves inaudible to humans for purposes such as ranging. In some embodiments, the audio circuit 407 may also include a headphone jack.

[0157] Positioning component 408 is used to locate the current geographical location of terminal 400 to implement navigation or LBS (Location Based Service). Positioning component 408 can be a positioning component based on the US GPS (Global Positioning System), China's Beidou system or Russia's Galileo system.

[0158] The power supply 409 is used to power various components in the terminal 400. The power supply 409 can be an alternating current, a direct current, a disposable battery, or a rechargeable battery. When the power supply 409 includes a rechargeable battery, the rechargeable battery can be a wired rechargeable battery or a wireless rechargeable battery. A wired rechargeable battery is a battery charged through a wired line, and a wireless rechargeable battery is a battery charged through a wireless coil. The rechargeable battery can also be used to support fast charging technology.

[0159] In some embodiments, the terminal 400 further includes one or more sensors 410 , including but not limited to: an acceleration sensor 411 , a gyroscope sensor 412 , a pressure sensor 413 , a fingerprint sensor 414 , an optical sensor 415 , and a proximity sensor 416 .

[0160] The acceleration sensor 411 can detect the magnitude of acceleration on the three coordinate axes of the coordinate system established by the terminal 400. For example, the acceleration sensor 411 can be used to detect the components of gravity acceleration on the three coordinate axes. The processor 401 can control the touch display screen 405 to display the user interface in a horizontal view or a vertical view according to the gravity acceleration signal collected by the acceleration sensor 411. The acceleration sensor 411 can also be used for collecting game or user motion data.

[0161] The gyroscope sensor 412 can detect the body direction and rotation angle of the terminal 400. The gyroscope sensor 412 can cooperate with the acceleration sensor 411 to collect the user's 3D (3 Dimensions) action on the terminal 400. The processor 401 can implement the following functions based on the data collected by the gyroscope sensor 412: motion sensing (such as changing the UI according to the user's tilt operation), image stabilization during shooting, game control, and inertial navigation.

[0162] The pressure sensor 413 can be set in the side frame of the terminal 400 and / or the lower layer of the touch display screen 405. When the pressure sensor 413 is set in the side frame of the terminal 400, it can detect the user's holding signal of the terminal 400, and perform left and right hand recognition or shortcut operation according to the holding signal. When the pressure sensor 413 is set in the lower layer of the touch display screen 405, it can control the operability control on the UI interface according to the user's pressure operation on the touch display screen 405. The operability control includes at least one of a button control, a scroll bar control, an icon control, and a menu control.

[0163] The fingerprint sensor 414 is used to collect the user's fingerprint to identify the user's identity based on the collected fingerprint. When the user's identity is identified as a trusted identity, the processor 401 authorizes the user to perform relevant sensitive operations, including unlocking the screen, viewing encrypted information, downloading software, paying, and changing settings. The fingerprint sensor 414 can be set on the front, back, or side of the terminal 400. When a physical button or a manufacturer logo is set on the terminal 400, the fingerprint sensor 414 can be integrated with the physical button or the manufacturer logo.

[0164] The optical sensor 415 is used to collect the ambient light intensity. In one embodiment, the processor 401 can control the display brightness of the touch display screen 405 according to the ambient light intensity collected by the optical sensor 415. Specifically, when the ambient light intensity is high, the display brightness of the touch display screen 405 is increased; when the ambient light intensity is low, the display brightness of the touch display screen 405 is reduced. In another embodiment, the processor 401 can also dynamically adjust the shooting parameters of the camera assembly 406 according to the ambient light intensity collected by the optical sensor 415.

[0165] The proximity sensor 416, also called a distance sensor, is usually arranged on the front of the terminal 400. The proximity sensor 416 is used to collect the distance between the user and the front of the terminal 400. In one embodiment, when the proximity sensor 416 detects that the distance between the user and the front of the terminal 400 is gradually decreasing, the processor 401 controls the touch display screen 405 to switch from the screen-on state to the screen-off state; when the proximity sensor 416 detects that the distance between the user and the front of the terminal 400 is gradually increasing, the processor 401 controls the touch display screen 405 to switch from the screen-off state to the screen-on state.

[0166] Those skilled in the art will understand that Fig.14 The structure shown in the figure does not constitute a limitation on the terminal 400, and the terminal 400 may include more or less components than those shown in the figure, or combine some components, or adopt a different component arrangement.

[0167] Embodiment 5

[0168] In an exemplary embodiment, a computer-readable storage medium is also provided, on which a computer program is stored. When the program is executed by a processor, a low-speed pedestrian warning sound design system for an electric vehicle is implemented as provided in all the inventive embodiments of the present application.

[0169] Any combination of one or more computer-readable media may be used. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, device, or device.

[0170] Computer-readable signal media may include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0171] Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0172] Computer program code for performing the operations of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0173] Embodiment 6

[0174] In an exemplary embodiment, an application product is also provided, including one or more instructions, which can be executed by the processor 401 of the above-mentioned device to complete the above-mentioned electric vehicle low-speed pedestrian warning sound design system.

[0175] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A design method for a low-speed pedestrian warning sound for an electric vehicle, characterized in that: include: Respectively obtain a frequency response characteristic curve of a white noise signal, a frequency response characteristic curve at a plane of a pedestrian warning speaker, a frequency response characteristic curve at a plane of a sound source speaker, and a frequency response characteristic curve at a front end of a vehicle of a sound source speaker; Obtaining a comprehensive transfer function through the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker, and the frequency response characteristic curve at the front end of the sound source speaker; Obtaining subjective output sound source material, and obtaining a subjective input sound source through the subjective output sound source material and a comprehensive transfer function; Obtain a corrected version of the input sound source through the subjective input sound source and the comprehensive transfer function; The comprehensive transfer function is obtained by the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker and the frequency response characteristic curve at the front end of the sound source speaker, including: The frequency response characteristic function of the white noise signal, the frequency response characteristic function at the plane of the pedestrian warning speaker, the frequency response characteristic function at the plane of the sound source speaker and the frequency response characteristic curve at the front end of the sound source speaker are obtained respectively through the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker and the frequency response characteristic curve at the front end of the sound source speaker; The comprehensive transfer function is obtained by using the frequency response characteristic function of the white noise signal, the frequency response characteristic function at the plane of the pedestrian warning speaker, the frequency response characteristic function at the plane of the sound source speaker, and the frequency response characteristic function at the front end of the sound source speaker through formula (1): Among them: B is the frequency response characteristic function of the pedestrian warning speaker plane, A0 is the frequency response characteristic function of the white noise signal, E is the frequency response characteristic function of the sound source speaker at the front end of the vehicle, D is the frequency response characteristic function of the sound source speaker plane, and Y is the comprehensive transfer function.

2. The method for designing a low-speed pedestrian warning sound for an electric vehicle according to claim 1, characterized in that: Also includes: The frequency response characteristic curve of the pedestrian warning speaker at the front end of the vehicle is obtained through the corrected input sound source, and the revised input sound source is obtained through the frequency response characteristic curve of the pedestrian warning speaker at the front end of the vehicle and the subjective output sound source material.

3. The design method of low-speed pedestrian warning sound for electric vehicles according to claim 1, characterized in that: The step of obtaining the subjective output sound source material and obtaining the subjective input sound source through the subjective output sound source material and the comprehensive transfer function includes: Obtain subjective output sound source material; Obtaining a subjective output sound source material frequency response characteristic function through the subjective output sound source material; The subjective input sound source is obtained through the subjective output sound source material frequency response characteristic function and the comprehensive transfer function.

4. The method for designing a low-speed pedestrian warning sound for an electric vehicle according to claim 1, characterized in that: The step of obtaining a corrected version of the input sound source through the subjective input sound source and the comprehensive transfer function includes: Obtaining a corrected version of the output sound source material through the subjective input sound source and the subjective output sound source material; The corrected version of the input sound source is obtained through the corrected version of the output sound source material and the comprehensive transfer function.

5. The method for designing a low-speed pedestrian warning sound for an electric vehicle according to claim 3, characterized in that: The step of obtaining a frequency response characteristic function of a subjective output sound source material through the subjective output sound source material comprises: Obtaining a subjective output sound source material frequency response characteristic curve through the subjective output sound source material; Obtaining a subjective output sound source material frequency response characteristic function through a subjective output sound source material frequency response characteristic curve; The subjective input sound source function is obtained by using the subjective output sound source material frequency response characteristic function and the comprehensive transfer function through formula (2): Among them, G is the subjective input sound source function, and F is the subjective output sound source material frequency response characteristic function; The subjective input sound source is obtained through the subjective input sound source function.

6. The method for designing a low-speed pedestrian warning sound for an electric vehicle according to claim 4, characterized in that: The method of obtaining a corrected version of the input sound source through the corrected version of the output sound source material and the integrated transfer function includes: Obtaining a frequency response characteristic curve of a calibrated version output sound source material by using the calibrated version output sound source material; The frequency response characteristic function of the corrected version output sound source material is obtained through the frequency response characteristic curve of the corrected version output sound source material; Obtaining a corrected version of the input sound source function through the corrected version of the output sound source material frequency response characteristic function and the comprehensive transfer function; The corrected version of the input sound source is obtained through the corrected version of the input sound source function.

7. A low-speed pedestrian warning sound design system for electric vehicles, characterized in that: The design system includes: An acquisition module, used to respectively acquire a frequency response characteristic curve of a white noise signal, a frequency response characteristic curve at a plane of a pedestrian warning speaker, a frequency response characteristic curve at a plane of a sound source speaker, and a frequency response characteristic curve at a front end of a vehicle of a sound source speaker; A fitting module, for obtaining a comprehensive transfer function through the frequency response characteristic curve of the white noise signal, the frequency response characteristic curve at the plane of the pedestrian warning speaker, the frequency response characteristic curve at the plane of the sound source speaker, and the frequency response characteristic curve at the front end of the sound source speaker; An analysis module, used to obtain subjective output sound source material, and obtain a subjective input sound source through the subjective output sound source material and a comprehensive transfer function; The correction module is used to obtain a corrected version of the input sound source through the subjective input sound source and the comprehensive transfer function.

8. A terminal, characterized in that: include: one or more processors; a memory for storing the one or more processor-executable instructions; Wherein, the one or more processors are configured to: Execute a method for designing a low-speed pedestrian warning sound for an electric vehicle as described in any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium, characterized in that: When the instructions in the storage medium are executed by the processor of the terminal, the terminal is enabled to execute the method for designing a low-speed pedestrian warning sound for an electric vehicle as described in any one of claims 1 to 6.

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