阅读说明：本技术 主动发声系统声音合成精度验证方法及主动发声系统 (Sound synthesis precision verification method for active sound production system and active sound production system ) 是由 曹蕴涛 刘英杰 汤乐超 于 2019-09-06 设计创作，主要内容包括：本发明涉及电动汽车主动发声系统技术领域,尤其涉及一种主动发声系统声音合成精度验证方法及主动发声系统。主动发声系统声音合成精度验证方法包括：确定需要加载到电动汽车的主动发声系统中的最终声音方案,得到主动发声系统声音目标；高保真声场还原系统条件下,模拟100％加速踏板开度下加速行驶工况,进行高保真声场还原系统条件下声音合成精度验证；实车静止条件下,模拟100％加速踏板开度下加速行驶工况,进行实车静止条件下声音合成精度验证。主动发声系统包括上述的主动发声系统声音合成精度验证方法。能够将系统本身电路及实车音响系统频率响应对声音合成精度的影响分解,明确控制系统与实车音响系统对主动发声系统声音合成精度的影响。(The invention relates to the technical field of active sounding systems of electric automobiles, in particular to a sound synthesis precision verification method of an active sounding system and the active sounding system. The verification method for the sound synthesis precision of the active sound production system comprises the following steps: determining a final sound scheme to be loaded into an active sound system of the electric automobile to obtain a sound target of the active sound system; simulating an acceleration running working condition under the condition of 100% of accelerator pedal opening under the condition of a high-fidelity sound field reduction system, and carrying out sound synthesis precision verification under the condition of the high-fidelity sound field reduction system; and under the static condition of the real vehicle, simulating the acceleration running working condition under the opening degree of an accelerator pedal of 100 percent, and verifying the sound synthesis precision under the static condition of the real vehicle. The active sounding system comprises the method for verifying the sound synthesis precision of the active sounding system. The influence of the system circuit and the real vehicle sound system frequency response on the sound synthesis precision can be decomposed, and the influence of the control system and the real vehicle sound system on the sound synthesis precision of the active sound production system can be determined.)

1. A method for verifying sound synthesis precision of an active sound production system is characterized by comprising the following steps:

determining a final sound scheme to be loaded into an active sound system of the electric automobile to obtain a sound target of the active sound system;

under the condition of a high-fidelity sound field reduction system, simulating an acceleration driving working condition under the condition of 100% of opening of an accelerator pedal, and carrying out sound synthesis precision verification on an active sound production system under the condition of the high-fidelity sound field reduction system;

and under the static condition of the real vehicle, simulating the acceleration running working condition under the opening degree of an accelerator pedal of 100 percent, and verifying the sound synthesis precision of the active sound production system under the static condition of the real vehicle.

2. The method for verifying the sound synthesis accuracy of the active sound production system according to claim 1, wherein sound design in an electric vehicle accelerating vehicle is performed, and a time domain signal, a spectrogram and a sound amplitude change curve of a final sound scheme to be loaded into the active sound production system are determined.

3. The verification method for the sound synthesis precision of the active sound production system according to claim 2, characterized in that discrete short-time Fourier transform analysis is performed on the sound signals of the order in the acceleration running vehicle corresponding to the final sound scheme, and the sound amplitude characteristic parameters and the phase characteristic parameters are extracted within the frequency range of 20-1200 Hz.

4. The verification method for sound synthesis accuracy of an active sound production system according to claim 3, wherein discrete short-time Fourier transform synthesis is performed according to the amplitude characteristic parameter and the phase characteristic parameter of the extracted order component sound to fit the synthesized sound of the final sound scheme, the difference between the synthesized sound and the sound of the final scheme is evaluated from the perspective of objective spectrum analysis and subjective listening trial, and parameter adjustment of appropriate discrete short-time Fourier transform analysis is performed for the difference condition, so that the fitted synthesized sound achieves the sound effect of the final scheme.

5. The method for verifying the sound synthesis accuracy of the active sound production system according to claim 4, wherein in terms of vehicle speed, the virtual engine speed is defined, the vehicle speed interval for active sound production in the electric vehicle is defined within the range of 0-120km/h, and a calculation formula of the virtual engine speed and the vehicle speed of the active sound production system is obtained according to the rule that the engine speed of the internal combustion engine vehicle linearly changes with the vehicle speed in a certain fixed gear:

n_V＝A×V+n_I

in the formula, n_VSimulating the engine speed for an active sound production system of the electric automobile; a is a virtual engine speed variation per vehicle speed, wherein:

and importing a calculation formula of the virtual engine speed and the vehicle speed of the active sound production system into the active sound production system, so that the active sound production system can calculate the virtual engine speed according to the vehicle speed.

6. The method for verifying the sound synthesis accuracy of the active sound production system according to claim 5, wherein a first curve of the sound amplitude gain of the active sound production system of the electric vehicle, which varies with the opening degree of the accelerator pedal, is obtained with respect to the opening degree of the accelerator pedal, and parameters of the first curve are introduced into the active sound production system, so that the active system can control the sound amplitude gain of the active sound production system according to the variation of the opening degree of the accelerator pedal.

7. The verification method for the sound synthesis precision of the active sound production system according to claim 6, characterized in that a high fidelity sound field reduction system is constructed by a plurality of high fidelity speakers to reduce the sound field environment in the electric vehicle, and the amplitude, delay and other interrelations between the speakers are adjusted to ensure that a high amplitude, straight and consistent frequency response can be obtained in the frequency range of the sound produced by the active sound production system at the target receiving point;

and connecting the active sounding control system with the high-fidelity sound field reduction system, controlling the active sounding system to send a white noise signal through the high-fidelity sound field reduction system under the environment of a whole vehicle semi-anechoic chamber, and testing sound response at a target receiving point so as to verify the actual frequency response condition of the high-fidelity sound field reduction system at the position of the target receiving point.

8. The verification method for the sound synthesis precision of the active sound production system according to claim 7, characterized in that the active sound production control system is connected to the whole vehicle, so that the system can normally read information such as vehicle speed, motor speed, accelerator pedal opening position and the like in the working process; on the basis of a loudspeaker of an original vehicle sound system of the electric vehicle, an active sound system of the electric vehicle is set up, and sound generated by the active sound system is played through the sound system;

under the environment of a semi-anechoic chamber of the whole vehicle, an active sounding system is controlled to send out a white noise signal through a sound system of the real vehicle, and sound response is tested at a target receiving point so as to verify the actual frequency response condition of the position of the target receiving point under the static condition of the real vehicle.

9. An active sound production system comprising the sound synthesis accuracy verification method of the active sound production system according to any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of active sounding systems of electric automobiles, in particular to a sound synthesis precision verification method of an active sounding system of an electric automobile and the active sounding system.

Background

The electric automobile cancels a power assembly system of a traditional automobile such as an engine, an air intake and exhaust system and the like, and is additionally provided with a driving motor, a power battery and the like, the sound in the electric automobile mainly comprises motor noise, road noise and wind noise, wherein the motor noise frequency characteristic is represented by a high frequency characteristic, and the road noise and the wind noise are represented by a broadband random noise characteristic. The electric automobile has no engine noise, although the amplitude of the noise in the automobile can be effectively reduced, due to the fact that the masking effect of the engine noise is avoided, the dynamic change of the sound in the automobile is represented by the motor order sound which changes along with the change of the automobile speed, and the motor order sound is mainly composed of a plurality of single pure sound components with high-frequency characteristics. Although the energy of the motor order components is not large, due to the characteristics of high frequency and single frequency pure tone, the amplitude is too large, and the motor order components can be annoying and uncomfortable in hearing.

Therefore, the motor order sound has a significant impact on the sound quality in an electric vehicle, and NVH engineers are working to control or even eliminate this sound. Under the development trend, the sounds in electric automobiles of different brands tend to be homogenized without sound quality characteristic identification, meanwhile, road noise and wind noise which change along with the dynamic running of the automobile are not enough to provide effective feedback information for a driver, and the lack of the feedback information in the sense of hearing can lead the driver to not fully control the running state of the automobile and possibly generate certain deviation for judging the running state of the automobile, so that an active sound production system is required to simulate the sounds in the internal combustion engine automobile, and the driver has good sound feedback.

However, in the process of developing and designing the active sounding system, the influence factors of the sound synthesis precision are more, and in order to realize the accurate control of the sound synthesis, the influence of each key link on the sound synthesis precision of the active sounding system needs to be determined

Therefore, a method for verifying sound synthesis accuracy of an active sound system and an active sound system are needed to solve the above technical problems.

Disclosure of Invention

The invention aims to provide a sound synthesis precision verification method and an active sound production system, which can effectively decompose the influence of the self circuit of the system and the frequency response of a real vehicle sound system on the sound synthesis precision, thereby defining the influence mechanism of the frequency response of the system and the real vehicle sound system on the sound frequency characteristic and the order characteristic of the active sound production system, indicating the direction for optimizing the sound synthesis precision of a subsequent active sound production system and improving the working efficiency in the development process of the active sound production system.

In order to achieve the purpose, the invention adopts the following technical scheme:

on one hand, the method for verifying the sound synthesis precision of the active sound production system comprises the following steps:

determining a final sound scheme to be loaded into an active sound system of the electric automobile to obtain a sound target of the active sound system;

simulating an acceleration running working condition under the condition of 100% of accelerator pedal opening under the condition of a high-fidelity sound field reduction system, and carrying out sound synthesis precision verification under the condition of the high-fidelity sound field reduction system;

and under the static condition of the real vehicle, simulating the acceleration running working condition under the opening degree of an accelerator pedal of 100 percent, and verifying the sound synthesis precision under the static condition of the real vehicle.

As an optimal scheme of the method for verifying the sound synthesis precision of the active sound production system, sound design in an accelerated driving vehicle of the electric vehicle is carried out, and a time domain signal, a frequency spectrogram and a sound amplitude change curve of a final sound scheme which needs to be loaded into the active sound production system are determined.

As an optimal scheme of the method for verifying the sound synthesis precision of the active sound production system, discrete short-time Fourier transform analysis is carried out on the order sound signals in the accelerated driving vehicle corresponding to the final sound scheme, and the sound amplitude characteristic parameters and the phase characteristic parameters are extracted within the frequency range of 20-1200 Hz.

The method is used as an optimal scheme of an active sound production system sound synthesis precision verification method, discrete short-time Fourier transform synthesis is carried out according to amplitude characteristic parameters and phase characteristic parameters of extracted order component sounds, synthetic sounds of a final sound scheme are fitted, differences between the synthetic sounds and the final scheme sounds are evaluated from the perspective of objective spectrum analysis and subjective audition, and parameter adjustment of appropriate discrete short-time Fourier transform analysis is carried out according to difference conditions, so that the fitted synthetic sounds achieve the sound effect of the final scheme.

As a preferred scheme of the verification method for the sound synthesis precision of the active sound production system, in the aspect of vehicle speed, the virtual engine rotating speed is defined, the vehicle speed interval of active sound production in the electric vehicle is defined within the range of 0-120km/h, and a calculation formula of the virtual engine rotating speed and the vehicle speed of the active sound production system can be obtained according to the rule that the engine rotating speed of an internal combustion engine vehicle linearly changes along with the vehicle speed in a certain fixed gear:

n_v＝A×V+n_I

in the formula, n_VSimulating the engine speed for an active sound production system of the electric automobile; a is a virtual engine speed variation per vehicle speed, wherein:

[(r/min)/(km/h)]wherein n is_RFor a virtual engine rated speed, n_IIs a virtual engine idle speed; v is the vehicle speed;

and importing a calculation formula of the virtual engine speed and the vehicle speed of the active sound production system into the active sound production system, so that the active sound production system can calculate the virtual engine speed according to the vehicle speed.

As an optimal scheme of the method for verifying the sound synthesis precision of the active sound production system, in the aspect of the opening degree of an accelerator pedal, a first curve of the sound amplitude gain of the active sound production system of the electric automobile, which changes along with the opening degree of the accelerator pedal, is obtained, and parameters of the first curve are led into the active sound production system, so that the active system can control the sound amplitude gain of the active sound production system according to the change of the opening degree of the accelerator pedal.

As an optimal scheme of the sound synthesis precision verification method of the active sound production system, a high-fidelity sound field reduction system is constructed through a plurality of high-fidelity loudspeakers to reduce the sound field environment in the electric automobile, and the amplitude, delay and other interrelations among the loudspeakers are adjusted to ensure that high-amplitude, straight and consistent frequency response can be obtained in the frequency range of sound produced by the active sound production system at a target receiving point;

and connecting the active sounding control system with the high-fidelity sound field reduction system, controlling the active sounding system to send a white noise signal through the high-fidelity sound field reduction system under the environment of a whole vehicle semi-anechoic chamber, and testing sound response at a target receiving point so as to verify the actual frequency response condition of the high-fidelity sound field reduction system at the position of the target receiving point.

As a preferred scheme of the verification method for the sound synthesis precision of the active sound production system, the active sound production control system is connected to the whole vehicle, so that the system can normally read information such as vehicle speed, motor rotating speed, accelerator pedal opening position and the like in the working process; on the basis of a loudspeaker of an original vehicle sound system of the electric vehicle, an active sound system of the electric vehicle is set up, and sound generated by the active sound system is played through the sound system;

under the environment of a semi-anechoic chamber of the whole vehicle, an active sounding system is controlled to send out a white noise signal through a sound system of the real vehicle, and sound response is tested at a target receiving point so as to verify the actual frequency response condition of the position of the target receiving point under the static condition of the real vehicle.

In another aspect, an active sound production system is provided, which includes the sound synthesis accuracy verification method of the active sound production system.

The invention has the beneficial effects that: the method is characterized in that the verification of the sound synthesis precision of the active sound production system is carried out under the conditions of a high-fidelity sound field restoration system and a real vehicle sound system static condition respectively, and the influence of the self circuit of the system and the frequency response of the real vehicle sound system on the sound synthesis precision can be effectively decomposed, so that the influence mechanism of the frequency response of the system and the real vehicle sound system on the sound frequency characteristic and the order characteristic of the active sound production system is definitely controlled, the direction is pointed for the optimization of the sound synthesis precision of the subsequent active sound production system, and the working efficiency in the development process of the active sound production system is improved.

Drawings

FIG. 1 is a schematic diagram of a final scheme time domain signal of an accelerated driving sound of an active sound system provided by the present invention;

FIG. 2 is a frequency spectrum diagram of a final scheme of an accelerated driving sound of the active sound production system provided by the invention;

FIG. 3 is a schematic representation of a virtual engine speed versus vehicle speed provided by the present invention;

FIG. 4 is a schematic diagram of a first curve of the sound amplitude gain of the active sound generation system according to the present invention as a function of the opening degree of the accelerator pedal;

FIG. 5 is an FFT spectrogram of an original white noise signal provided by the present invention;

FIG. 6 is a white noise signal FFT spectrogram for the target receiving point position test of the high fidelity sound field restoration system provided by the present invention;

FIG. 7 is a schematic diagram of a sound test result of an active sound system for simulating acceleration driving under the condition of 100% of opening of an accelerator pedal under the condition of a high-fidelity sound field restoration system provided by the invention;

FIG. 8 is a schematic diagram of FFT spectrum comparison results of sounds of an active sound generating system for simulating accelerated driving under the condition of 100% of opening of an accelerator pedal under the condition of a high-fidelity sound field reduction system provided by the invention and sounds in a design state;

FIG. 9 is a frequency response FFT spectrogram for a sound system for testing the position of the right ear of a driver in a vehicle according to the present invention;

FIG. 10 is a schematic diagram of comparison of sound amplitude variation curves of an active sound generating system for simulating acceleration driving under 100% of opening of an accelerator pedal under a static condition of an actual vehicle sound system provided by the invention;

FIG. 11 is a schematic diagram showing the FFT spectrum comparison result between the sound of the active sounding system for simulating acceleration running under 100% of the opening degree of the accelerator pedal under the static condition of the real vehicle acoustic system provided by the invention and the sound in the design state.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that are conventionally placed when the products of the present invention are used, and are used only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements to be referred to must have specific orientations, be constructed in specific orientations, and operate, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; either mechanically or electrically. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.