Air inlet order noise target grading formulating method and device based on harmonic frequency signal sounder

Abstract

The invention discloses an air inlet order noise target grading formulating method and device based on a harmonic frequency signal sounder, and the method comprises the steps: dividing in-vehicle noise into in-vehicle air inlet order noise and in-vehicle background noise caused by other factors, and obtaining the in-vehicle background noise; calculating the characteristic loudness of the corresponding in-vehicle background noise under each driving working condition of the vehicle, and performing target grading formulation on the in-vehicle air inlet order noise based on the characteristic loudness of the in-vehicle background noise; air inlet order noise of the air inlet is simulated through a harmonic frequency signal sounder at the air inlet, so that the frequency and the amplitude of the noise transmitted into the vehicle are the same as the frequency and the amplitude of the air inlet order noise in the vehicle of the corresponding target at each stage; simulated air inlet order noise is obtained, and air inlet order noise target grading formulation is carried out according to the simulated air inlet order noise; according to the method, separation of in-vehicle air inlet order noise and other background noise is realized, in-vehicle air inlet order noise target grading setting based on human auditory system perception is realized, and in-vehicle air inlet order noise based on quantitative active sound production is decomposed to air inlet order noise.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle noise control, and in particular to a method and device for grading an air intake order noise target based on a harmonic frequency signal generator. Background Art

[0002] The order noise of the engine intake system is an important indicator that affects the ride comfort of a car. The intake pipe of a passenger car is generally arranged on the upper side of the front grille. The order noise of the intake port is transmitted to the interior of the car through the air-front sound insulation materials on the upper and lower sides of the engine hood, the body sheet metal and the windshield. Excessive intake order noise often resonates with the sheet metal or the sound cavity inside the car to produce a "booming" sound, causing the noise inside the car to affect communication between passengers. In severe cases, the eardrum of the human ear is impacted by sound waves, causing tinnitus, irritability, and even dizziness, affecting the physical and mental health of passengers. At present, the benchmarking method is often used when developing new models. According to the intake order noise of competitors' models on sale, the development target of the intake order noise of the newly developed models is formulated.

[0003] The current problems with this technology include the fact that the entire vehicle is a complex, multi-excitation, multi-transmission path vibration and noise system. In addition to the intake order noise, there are also noises caused by wind excitation, road excitation, powertrain excitation, exhaust system excitation, etc. Different models have different structures, and the noises of each part vary greatly. Whether the intake order noise in the car can be perceived by the passengers is not only related to its size, but also to the size of other noises in the car. There is a great risk in only considering the size of the intake order noise in the car, and it needs to be matched according to different models; the intake order noise is transmitted to the car after being attenuated by the sound insulation of the body parts. The size of the intake order noise in the car perceived by the passengers is not only related to the intake order noise, but also related to the body noise transfer function. If only the benchmarking method is adopted and the target of the newly developed model is formulated according to the intake order noise of the benchmark car, the influence of other excitation noise and body sound insulation attenuation characteristics on passenger perception will be ignored. In addition, if the intake order noise target is too strict, it will lead to high cost and weight of the intake silencer solution, resulting in waste; and if the intake order noise target is too loose, it will lead to excessive noise in the car, affecting product competitiveness. Therefore, the formulation of the intake order noise target needs to comprehensively consider multiple factors such as the acoustic performance of the whole vehicle, the cost of the whole vehicle, and the market competitiveness. Summary of the invention

[0004] The purpose of the present invention is to provide a method and device for setting target grading of air intake order noise based on a harmonic signal generator, which realizes the separation of in-vehicle air intake order noise from other background noises, the setting of in-vehicle air intake order noise target grading based on the perception of the human auditory system, and the decomposition of in-vehicle air intake order noise into air intake order noise based on quantitative active sounding, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for setting an inlet order noise target classification based on a harmonic signal generator, comprising:

[0006] The vehicle interior noise is divided into the vehicle interior intake order noise and the vehicle interior background noise caused by other factors, and the vehicle interior background noise is obtained;

[0007] Calculate the characteristic loudness of the corresponding interior background noise under various vehicle driving conditions, and set target classification for the interior intake order noise based on the characteristic loudness of the interior background noise;

[0008] The inlet order noise of the air inlet is simulated by a harmonic signal generator at the air inlet so that the frequency and amplitude transmitted into the vehicle are the same as the inlet order noise frequency and amplitude of the corresponding levels of targets;

[0009] The simulated intake order noise is obtained, and the intake order noise target is graded based on the simulated intake order noise.

[0010] Further, the vehicle interior noise is divided into vehicle interior intake order noise and vehicle interior background noise caused by other factors, and the vehicle interior background noise is obtained, which also includes:

[0011] The vehicle's air intake port is silenced to eliminate the intake order noise inside the vehicle, thereby obtaining the background noise inside the vehicle caused by other factors inside the vehicle.

[0012] Furthermore, calculating the characteristic loudness of the corresponding vehicle interior background noise under each driving condition of the vehicle also includes:

[0013] Under idling conditions, the background noise in the vehicle is subjected to discrete Fourier transform to convert the discrete time domain signal into a frequency domain signal. The discrete Fourier transform formula is:

[0014]

[0015] Where x[n] is the time domain signal of the vehicle interior background noise, N is the number of time domain signal points, and X(f) is the noise amplitude at frequency f;

[0016] Based on the in-vehicle background noise spectrum X(f), it is grouped according to the upper and lower limits of the 1 / 3 octave band, the mean square value of the sound pressure in the same 1 / 3 octave band is calculated and converted into the sound pressure level. The calculation formula is:

[0017]

[0018] Where, L T is the sound pressure level corresponding to 1 / 3 octave band, p i is the sound pressure at frequency i, p ref The reference sound pressure is 2×10 -5 pa.

[0019] Furthermore, the sound pressure level within the 1 / 3 octave band is corrected, which is divided into low-frequency correction, human ear transfer characteristic correction, and hearing threshold correction;

[0020] According to the sound pressure level after 1 / 3 octave correction, calculate the main loudness corresponding to the 1 / 3 octave sound pressure level. The calculation formula is:

[0021]

[0022] The 1 / 3 octave center frequency is converted into the critical band Bark domain, and the characteristic loudness corresponding to the background noise in the car is calculated based on the masking effect and the characteristic loudness slope.

[0023] Furthermore, target grading of the in-vehicle intake order noise is formulated based on characteristic loudness, and further includes:

[0024] Based on the masking effect, when the characteristic loudness of the intake order noise in the car is equal to the characteristic loudness of the background noise in the car, the sound pressure level corresponding to the intake order noise in the car is set as the initial sound pressure. The human ear cannot perceive the intake order noise in the car under the initial sound pressure.

[0025] The perception state in which the human ear feels uncomfortable with the intake order noise in the vehicle is set as poor perception, and multiple levels of the human ear's intake order noise in the vehicle are set from no perception to poor perception according to the perception degree, as the target grading setting of the intake order noise in the vehicle.

[0026] Furthermore, the air intake order noise of the air intake port is simulated by a harmonic signal generator at the air intake port so that the frequency and amplitude of the air intake order noise transmitted into the vehicle are the same as the frequency and amplitude of the air intake order noise of the corresponding levels of targets in the vehicle, and further comprising:

[0027] Establish the mapping relationship between each level of target in-vehicle intake order noise and vehicle driving parameters under each driving condition of the vehicle;

[0028] Make the simulated air intake order noise under the vehicle driving parameters the same in frequency and amplitude as the in-vehicle air intake order noise of the corresponding levels of targets.

[0029] Furthermore, calculating the characteristic loudness of the corresponding vehicle interior background noise under each driving condition of the vehicle also includes:

[0030] When the vehicle is in a non-steady-state condition of acceleration or coasting, the background noise inside the vehicle is segmented at preset time intervals when the engine speed changes;

[0031] Approximate the transient noise signal of acceleration or sliding to a steady-state signal;

[0032] The target classification of the intake order noise in the vehicle is set according to the steady-state signal.

[0033] On the other hand, a device for setting an air inlet order noise target classification based on a harmonic signal generator is provided, comprising:

[0034] A noise separation module is used to divide the in-vehicle noise into in-vehicle intake order noise and in-vehicle background noise caused by other factors, and obtain the in-vehicle background noise;

[0035] A target classification module is used to calculate the characteristic loudness of the corresponding interior background noise under various driving conditions of the vehicle, and to classify the interior intake order noise based on the characteristic loudness of the interior background noise;

[0036] The module for simulating the air intake order noise of the air intake port is used to simulate the air intake order noise of the air intake port at the air intake port so that the frequency and amplitude of the air intake order noise transmitted into the vehicle are the same as the frequency and amplitude of the air intake order noise of the vehicle at the corresponding levels of targets;

[0037] The air inlet order noise target classification setting module obtains the simulated air inlet order noise and performs the air inlet order noise target classification setting according to the simulated air inlet order noise.

[0038] Furthermore, the noise separation module further includes:

[0039] The silencer module silences the vehicle's air intake port and eliminates the intake order noise inside the vehicle, thereby obtaining the background noise inside the vehicle caused by other factors inside the vehicle.

[0040] Furthermore, the module for simulating the air intake order noise of the air intake port also includes:

[0041] A harmonic signal generator generates a harmonic sounder at the engine order noise frequency, and emits a simulated intake order noise through the harmonic sounder;

[0042] The regulating module is used to regulate the frequency and amplitude of the simulated air intake order noise emitted by the harmonic signal generator, so that the frequency and amplitude of the simulated air intake order noise are the same as the frequency and amplitude of the in-vehicle air intake order noise of the corresponding levels of targets.

[0043] Compared with the prior art, the beneficial effects of the present invention are: separating the in-vehicle air intake order noise from other noises, preparing for the analysis of the contribution of the in-vehicle air intake order noise to the in-vehicle noise; formulating the in-vehicle air intake order noise grading target based on the human-perceived air intake order noise evaluation; and decomposing the in-vehicle air intake order noise target into the air intake order noise, and decomposing the in-vehicle air intake order noise grading target into the air intake pipe order noise, so as to achieve the decoupling of the air intake noise development from other system noises; achieving the formulation of the air intake order noise grading target based on passenger perception, matching the air intake order noise development target according to the positioning of the vehicle model, and achieving the optimal development of customer perception, cost, weight and other performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A flow chart of a method for formulating an air inlet order noise target classification based on a harmonic signal generator in an embodiment of the present invention;

[0045] Figure 2 Schematic diagram of characteristic response curve of intake order noise in an embodiment of the present invention;

[0046] Figure 3 It is a schematic diagram of an octave band in an embodiment of the present invention;

[0047] Figure 4 Schematic diagram of masking effect in an embodiment of the present invention;

[0048] Figure 5 A block diagram of the connection of an air inlet order noise target classification setting device based on a harmonic signal generator in an embodiment of the present invention;

[0049] In the figure: 10, noise separation module; 20, target classification module; 30, air inlet order noise simulation module; 40, air inlet order noise target classification module. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0051] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and 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 orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0052] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" 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 an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] Please refer to the attached drawings of the specification. The present invention provides a technical solution: a method for setting an inlet order noise target classification based on a harmonic signal generator, comprising the following steps:

[0054] S102, dividing the vehicle interior noise into vehicle interior intake order noise and vehicle interior background noise caused by other factors, and obtaining the vehicle interior background noise;

[0055] Specifically, the vehicle interior noise is divided into vehicle interior intake order noise and vehicle interior background noise caused by other factors, and the vehicle interior background noise is obtained, which also includes:

[0056] The vehicle's air intake port is silenced to eliminate the intake order noise inside the vehicle, thereby obtaining the background noise inside the vehicle caused by other factors inside the vehicle.

[0057] Among them, the time domain transfer path analysis method (TPA) is a method for fitting the in-vehicle noise and path decomposition. The time domain TPA system is divided into three parts: excitation source, transfer path and in-vehicle response. The excitation source is the sound pressure signal at the sound source of airborne noise or the excitation force at the active end of structure-borne noise. The transfer function describes the relationship between the excitation source and the in-vehicle response. The sound pressure at the in-vehicle response point is the vector sum of the excitation source propagating to the vehicle along different paths. The calculation formula is:

[0058]

[0059] Where P response is the sound pressure at the response point in the car; P iair is the noise pressure of the ith air propagation path; X j is the excitation force of the jth structural path; H iair is the transfer function of the ith air propagation path; H jstru is the transfer function of the jth structural transfer path;

[0060] Applying the time domain transfer path analysis method, a TPA model of the interior noise of the whole vehicle is constructed. It can be seen from the TPA model of the interior noise of the whole vehicle that the intake noise is only transmitted to the interior of the vehicle through the air transfer path. A large-volume muffler is designed so that its silencing capacity is more than 10 times that of the traditional intake system. The large-volume muffler is connected in series to the intake pipe port, and the silencing capacity of the intake system is greatly enhanced. At this time, the intake order noise is significantly attenuated, and its contribution to the interior noise can be ignored. The interior noise before and after the large-volume muffler is connected in series is tested separately, and the difference between the two working conditions can be obtained to obtain the interior intake order noise. The interior noise measured under the condition of the large-volume muffler in series is the total interior noise caused by other factors, which realizes the separation of the interior intake order noise from other noises.

[0061] Inlet order noise is often low-frequency noise, and its frequency components are:

[0062]

[0063] In the formula, z is the number of cylinders; n is the engine speed, r / min; τ is the number of engine strokes, which is usually a 4-stroke engine; k is the simple harmonic order, and the frequency components with k>3 are generally ignored, and the first 3 order noises are controlled;

[0064] According to the above method for separating the in-vehicle intake order noise, the first three main order noises of the in-vehicle intake under conditions such as vehicle idling, idling with air conditioning, partial load acceleration, full load acceleration, and coasting are separated. The in-vehicle intake order noise under each condition and the total in-vehicle noise caused by other factors, namely, the in-vehicle background noise, are obtained respectively, in preparation for the formulation and evaluation of the in-vehicle intake order noise classification targets.

[0065] S104, calculating the characteristic loudness of the corresponding vehicle interior background noise under various vehicle driving conditions, and setting a target classification for the vehicle interior intake order noise based on the characteristic loudness of the vehicle interior background noise;

[0066] Among them, when a weaker sound and another stronger sound appear in the environment, the human auditory system only perceives the stronger sound, and the weaker sound is difficult to be detected. This phenomenon is called the masking effect; Figure 2 As shown, when the characteristic loudness corresponding to the intake order noise in the car is lower than the characteristic loudness of the background noise, the intake order noise is masked by the background noise, and the human ear cannot perceive the intake order noise at this time; on the contrary, when the characteristic loudness corresponding to the intake order noise in the car is greater than the characteristic loudness of the background noise, the intake order noise cannot be masked by the background noise, and the human ear can perceive the intake order noise at this time; when the characteristic loudness of the intake order noise in the car is equal to the characteristic loudness of the background noise, the sound pressure level corresponding to the intake order noise in the car is not perceptible to the passengers;

[0067] The masking effect is one of the most basic effects in psychoacoustics. Simply put, it refers to the phenomenon that a sound of one frequency prevents the auditory system from perceiving a sound of another frequency. The former is called the masking sound, and the latter is called the masked sound. When the masking sound and the masking sound appear at the same time, and the masked sound is just masked, the energy level of the masked sound is called the masking threshold. When the sound level of the masked sound exceeds the masking threshold, the masked sound is partially masked, and when it is lower than the masking threshold, it is completely masked by the masking sound, that is, the masked sound becomes weak or even completely inaudible due to the appearance of the masking sound, such as Figure 3 shown.

[0068] Specifically, calculating the characteristic loudness of the corresponding vehicle interior background noise under various vehicle driving conditions also includes:

[0069] Under idling conditions, the background noise in the vehicle is subjected to discrete Fourier transform to convert the discrete time domain signal into a frequency domain signal. The discrete Fourier transform formula is:

[0070]

[0071] Where x[n] is the time domain signal of the vehicle interior background noise, N is the number of time domain signal points, and X(f) is the noise amplitude at frequency f;

[0072] Based on the in-vehicle background noise spectrum X(f), it is grouped according to the upper and lower limits of the 1 / 3 octave band, the mean square value of the sound pressure in the same 1 / 3 octave band is calculated and converted into the sound pressure level. The calculation formula is:

[0073]

[0074] Where, L T is the sound pressure level corresponding to 1 / 3 octave band, p i is the sound pressure at frequency i, p ref The reference sound pressure is 2×10 -5 pa;

[0075] It is understandable that the human ear can hear sounds at a frequency of about 20 to 20,000 Hz, but the sensitivity to different frequencies is different: it is easy to distinguish low frequencies, such as 50 Hz and 100 Hz; but it is increasingly difficult to distinguish high frequencies, such as 10,000 Hz and 10,050 Hz. Therefore, in spectrum analysis, low frequencies are divided as finely as possible to reflect their characteristics more vividly and facilitate analysis; high frequencies are divided as roughly as possible to blur the insensitive frequency characteristics. This is the idea of ​​octave processing; octave (Octave) is usually used in NVH spectrum analysis, indicating that two adjacent frequencies are 2 n The multiple relationship is geometrically spaced. The value of n is the number of octaves. The combination of numbers and shapes is explained as follows: Figure 4 As shown;

[0076] It can be seen that the 1 / 3 octave frequency f u =2 1 / 3 f l ; f u is the upper frequency limit, f l is the lower frequency limit, f T is the center frequency. The center frequency is usually rounded to an integer. Common 1 / 3 octave band frequencies are shown in Table 6.

[0077] Table 6 1 / 3 octave band frequencies

[0078]

[0079]

[0080]

[0081] Specifically, the sound pressure level within the 1 / 3 octave band is corrected, which is divided into low-frequency correction, human ear transfer characteristic correction, and hearing threshold correction; among which, the center frequency f of each 1 / 3 octave band is T The corresponding correction values ​​are shown in Tables 1-3. Table 1 is the correction value ΔL for the low-frequency 1 / 3 octave band sound pressure level, Table 2 is the correction value a0 for the human ear transfer characteristic sound pressure level, and Table 3 is the hearing threshold L. TQ And correction value ΔL CB ;

[0082] Table 1 Low frequency 1 / 3 octave band sound pressure level correction ΔL

[0083]

[0084] Table 2 Correction value a0 for sound pressure level of human ear transfer characteristic

[0085]

[0086]

[0087] Table 3 Hearing threshold L TQ And correction value ΔL CB

[0088] <![CDATA[f T ,Hz]]> <![CDATA[L TQ ,dB]]> <![CDATA[ΔL CB ,dB]]> <![CDATA[f T ,Hz]]> <![CDATA[L TQ ,dB]]> <![CDATA[ΔL CB ,dB]]> <![CDATA[f T ,Hz]]> <![CDATA[L TQ ,dB]]> <![CDATA[ΔL CB ,dB]]> 25 30 -0.25 250 12 -0.8 2500 3 1.7 31.5 30 -0.25 315 8 -0.8 3150 3 1.6 40 30 -0.25 400 7 -0.5 4000 3 1.4 50 30 -0.25 500 6 0.0 5000 3 1.2 63 30 -0.25 630 5 0.5 6300 3 0.8 80 30 -0.25 800 4 1.1 8000 3 0.5 100 18 -0.6 1000 3 1.5 10000 3 0.0 125 18 -0.6 1250 3 1.7 12500 3 -0.5 160 18 -0.6 1600 3 1.8 16000 200 12 -0.8 2000 3 1.8 20000

[0089] According to the sound pressure level after 1 / 3 octave correction, calculate the main loudness corresponding to the 1 / 3 octave sound pressure level. The calculation formula is:

[0090]

[0091] The 1 / 3 octave center frequency is converted into the critical band Bark domain, and the characteristic loudness corresponding to the background noise in the car is calculated based on the masking effect and the characteristic loudness slope.

[0092] Among them, the corresponding relationship between the center frequency, critical bandwidth number and critical frequency band is shown in Table 4; based on the masking effect and characteristic loudness slope, see Table 5, the characteristic loudness corresponding to the background noise in the car is calculated;

[0093] Table 4 Correspondence between center frequency, critical bandwidth number and critical frequency band

[0094]

[0095]

[0096] Table 5 Loudness slope

[0097]

[0098] Specifically, calculating the characteristic loudness of the corresponding vehicle interior background noise under various driving conditions of the vehicle also includes: when the vehicle is in an acceleration or coasting non-steady-state condition, segmenting the vehicle interior background noise at a preset time interval of the engine speed change;

[0099] Approximate the transient noise signal of acceleration or sliding to a steady-state signal;

[0100] The target classification of the intake order noise in the vehicle is set according to the steady-state signal.

[0101] Among them, for non-steady-state operating conditions such as vehicle acceleration and coasting, a method based on engine speed slicing is adopted. Preferably, the background noise inside the vehicle is segmented at a time interval of 50r / min when the engine speed changes, and the transient noise signals such as acceleration and coasting are approximated as steady-state signals. Then, the intake order noise target in the vehicle is graded and set.

[0102] Specifically, the target classification of the intake order noise in the vehicle is formulated based on the characteristic loudness, and also includes:

[0103] Based on the masking effect, when the characteristic loudness of the intake order noise in the car is equal to the characteristic loudness of the background noise in the car, the sound pressure level corresponding to the intake order noise in the car is set as the initial sound pressure. The human ear cannot perceive the intake order noise in the car under the initial sound pressure.

[0104] The perception state in which the human ear feels uncomfortable with the intake order noise in the vehicle is set as poor perception, and multiple levels of the human ear's intake order noise in the vehicle are set from no perception to poor perception according to the perception degree, as the target grading setting of the intake order noise in the vehicle.

[0105] Among them, Figure 2 Taking the characteristic loudness of the noise as an example, when the characteristic loudness corresponding to the intake order noise in the car is lower than the characteristic loudness of the background noise, the intake order noise is masked by the background noise, and the human ear cannot perceive the intake order noise at this time; on the contrary, when the characteristic loudness corresponding to the intake order noise in the car is greater than the characteristic loudness of the background noise, the intake order noise cannot be masked by the background noise, and the human ear can perceive the intake order noise at this time; when the characteristic loudness of the intake order noise in the car is equal to the characteristic loudness of the background noise, the sound pressure corresponding to the intake order noise in the car Level is the initial sound pressure and passengers cannot perceive the intake order noise; according to development experience, when the intake order noise in the car is 8dB higher than the initial sound pressure, passengers can easily perceive the intake order noise, and the perception is poor; between imperceptible and poor, it is divided into 5 levels, and the intake order noise target is set in a graded manner, corresponding to the perception states of no perception, difficult to perceive, perceptible, easy to perceive, and poor perception, see Table 7, to achieve the definition of the intake order noise target of the whole vehicle in a hierarchical manner according to the positioning of different vehicle models.

[0106] Table 7 Grading evaluation based on masking effect

[0107]

[0108] S106, simulating the intake order noise of the air intake port through a harmonic signal generator at the air intake port so that the frequency and amplitude of the intake order noise transmitted into the vehicle are the same as the frequency and amplitude of the intake order noise of the vehicle at the corresponding levels of targets;

[0109] Specifically, the air intake order noise of the air intake port is simulated by a harmonic signal generator at the air intake port so that the frequency and amplitude of the air intake order noise transmitted into the vehicle are the same as the frequency and amplitude of the air intake order noise of the corresponding levels of targets in the vehicle, and also includes:

[0110] Establish the mapping relationship between each level of target in-vehicle intake order noise and vehicle driving parameters under each driving condition of the vehicle;

[0111] Make the simulated air intake order noise under the vehicle driving parameters the same in frequency and amplitude as the in-vehicle air intake order noise of the corresponding levels of targets.

[0112] Among them, the decomposition of the in-vehicle intake order noise into the intake port order noise based on quantitative active sound generation is achieved through active sound generation technology. Its principle is to use the traditional fuel vehicle as the carrier to establish a mapping relationship between the in-vehicle noise and the vehicle driving parameters such as vehicle speed, pedal opening, assembly output torque, and speed, as shown in formula (5). By extracting the driving parameters of the electric vehicle, a sound that meets the frequency and amplitude characteristics of the traditional vehicle is synthesized in real time. The DSP controller drives the power amplifier to control the speaker to emit the synthesized sound, so that the in-vehicle sound characteristics felt by the passengers are consistent with those of the traditional fuel vehicle.

[0113]

[0114] Where V is the vehicle speed, n is the motor / engine speed, p is the pedal opening, T is the assembly output torque, ω is the weight corresponding to each parameter, H is the sound transfer function from the speaker to the occupant position, SPL is the in-vehicle order sound pressure level;

[0115] In this embodiment, the process of implementing the decomposition of the quantitative vehicle intake order noise into the intake port order noise based on the active sound generation method is as follows:

[0116] An active sound generation system is designed, which consists of a loudspeaker, an error microphone, a DSP controller and an active sound generation algorithm. The loudspeaker is placed in the air filter of the intake system to simulate the process of intake order noise being emitted from the intake system. The error microphone is placed on the seat headrest, at a distance of (0.2±0.02)m from the central symmetry plane of the seat and (0.7±0.05)m from the seat plane, to simulate the noise measurement point inside the vehicle. The DSP is connected to the loudspeaker and the error microphone respectively to realize the noise collection of the target point inside the vehicle and the control of the sound generation of the loudspeaker. A harmonic sound generator is generated with the engine order noise frequency to control the frequency of the sound generated by the loudspeaker. The search target is to minimize the difference between the error microphone and the target classification of the order noise inside the vehicle, and to control the amplitude of the sound generated by the loudspeaker, so that the sound of the loudspeaker is transmitted into the vehicle. The target classification of the order noise inside the vehicle is the same as the noise frequency and amplitude of the order noise transmitted into the vehicle from the air intake.

[0117] S108, obtaining simulated intake order noise, and setting intake order noise target classification according to the simulated intake order noise.

[0118] For example, a vehicle is placed in an anechoic chamber with the engine turned off, and the order noise at the intake pipe outlet is measured during the above process to achieve quantitative decomposition of the intake order noise inside the vehicle into the intake outlet order noise.

[0119] On the other hand, Figure 5 As shown, a device for setting an air inlet order noise target classification based on a harmonic signal generator is provided, comprising:

[0120] The noise separation module 10 is used to divide the in-vehicle noise into in-vehicle intake order noise and in-vehicle background noise caused by other factors, and obtain the in-vehicle background noise;

[0121] A target classification setting module 20 is used to calculate the characteristic loudness of the corresponding vehicle interior background noise under various vehicle driving conditions, and to perform target classification setting for the vehicle interior intake order noise based on the characteristic loudness of the vehicle interior background noise;

[0122] The air intake order noise simulation module 30 is used to simulate the air intake order noise of the air intake through a harmonic signal generator at the air intake so that the frequency and amplitude of the air intake order noise transmitted into the vehicle are the same as the frequency and amplitude of the air intake order noise of the vehicle at the corresponding levels of targets;

[0123] The air inlet order noise target classification setting module 40 obtains simulated air inlet order noise, and performs air inlet order noise target classification setting according to the simulated air inlet order noise.

[0124] Optionally, the noise separation module further includes:

[0125] The silencer module silences the vehicle's air intake port and eliminates the intake order noise inside the vehicle, thereby obtaining the background noise inside the vehicle caused by other factors inside the vehicle.

[0126] Optionally, the module for simulating air inlet order noise also includes:

[0127] A harmonic signal generator generates a harmonic sounder at the engine order noise frequency, and emits a simulated intake order noise through the harmonic sounder;

[0128] The regulating module is used to regulate the frequency and amplitude of the simulated air intake order noise emitted by the harmonic signal generator, so that the frequency and amplitude of the simulated air intake order noise are the same as the frequency and amplitude of the in-vehicle air intake order noise of the corresponding levels of targets.

[0129] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for setting inlet order noise targets based on harmonic signal generators, characterized in that: include: The vehicle interior noise is divided into the vehicle interior intake order noise and the vehicle interior background noise caused by other factors, and the vehicle interior background noise is obtained; Calculate the characteristic loudness of the corresponding interior background noise under various vehicle driving conditions, and set target classification for the interior intake order noise based on the characteristic loudness of the interior background noise; The inlet order noise of the air inlet is simulated by a harmonic signal generator at the air inlet so that the frequency and amplitude transmitted into the vehicle are the same as the inlet order noise frequency and amplitude of the corresponding levels of targets; The simulated intake order noise is obtained, and the intake order noise target is graded based on the simulated intake order noise.

2. The method for setting the target classification of inlet order noise based on harmonic signal generator according to claim 1 is characterized in that: The vehicle interior noise is divided into the vehicle interior intake order noise and the vehicle interior background noise caused by other factors, and the vehicle interior background noise is obtained, which also includes: The vehicle's air intake port is silenced to eliminate the intake order noise inside the vehicle, thereby obtaining the background noise inside the vehicle caused by other factors inside the vehicle.

3. The method for setting the target classification of inlet order noise based on harmonic signal generator according to claim 1 is characterized in that: Calculate the characteristic loudness of the corresponding vehicle interior background noise under various driving conditions, including: Under idling conditions, the background noise in the vehicle is subjected to discrete Fourier transform to convert the discrete time domain signal into a frequency domain signal. The discrete Fourier transform formula is: Where x[n] is the time domain signal of the vehicle interior background noise, N is the number of time domain signal points, and X(f) is the noise amplitude at frequency f; Based on the in-vehicle background noise spectrum X(f), it is grouped according to the upper and lower limits of the 1 / 3 octave band, the mean square value of the sound pressure in the same 1 / 3 octave band is calculated and converted into the sound pressure level. The calculation formula is: Where, L T is the sound pressure level corresponding to 1 / 3 octave band, p i is the sound pressure at frequency i, p ref The reference sound pressure is 2×10 -5 pa.

4. The method for setting the target classification of inlet order noise based on harmonic signal generator according to claim 3 is characterized in that: include: Correct the sound pressure level within the 1 / 3 octave band, including low-frequency correction, human ear transfer characteristic correction, and hearing threshold correction; According to the sound pressure level after 1 / 3 octave correction, calculate the main loudness corresponding to the 1 / 3 octave sound pressure level. The calculation formula is: The 1 / 3 octave center frequency is converted into the critical band Bark domain, and the characteristic loudness corresponding to the background noise in the car is calculated based on the masking effect and the characteristic loudness slope.

5. The method for setting the target classification of inlet order noise based on harmonic signal generator according to claim 1, characterized in that: Target classification of vehicle intake order noise based on characteristic loudness, including: Based on the masking effect, when the characteristic loudness of the intake order noise in the car is equal to the characteristic loudness of the background noise in the car, the sound pressure level corresponding to the intake order noise in the car is set as the initial sound pressure. The human ear cannot perceive the intake order noise in the car under the initial sound pressure. The perception state in which the human ear feels uncomfortable with the intake order noise in the vehicle is set as poor perception, and multiple levels of the human ear's intake order noise in the vehicle are set from no perception to poor perception according to the perception degree, as the target grading setting of the intake order noise in the vehicle.

6. The method for setting the target classification of inlet order noise based on harmonic signal generator according to claim 1, characterized in that: The air intake order noise of the air intake is simulated by a harmonic signal generator at the air intake so that the frequency and amplitude of the air intake order noise transmitted into the vehicle are the same as the frequency and amplitude of the air intake order noise of the corresponding levels of targets in the vehicle, and also includes: Establish the mapping relationship between each level of target in-vehicle intake order noise and vehicle driving parameters under each driving condition of the vehicle; Make the simulated air intake order noise under the vehicle driving parameters the same in frequency and amplitude as the in-vehicle air intake order noise of the corresponding levels of targets.

7. The method for setting the target classification of inlet order noise based on harmonic signal generator according to claim 1, characterized in that: Calculate the characteristic loudness of the corresponding vehicle interior background noise under various driving conditions, including: When the vehicle is in a non-steady-state condition of acceleration or coasting, the background noise inside the vehicle is segmented at preset time intervals when the engine speed changes; Approximate the transient noise signal of acceleration or sliding to a steady-state signal; The target classification of the intake order noise in the vehicle is set according to the steady-state signal.

8. A device for setting target classification of inlet order noise based on a harmonic signal generator, characterized in that: include: A noise separation module is used to divide the in-vehicle noise into in-vehicle intake order noise and in-vehicle background noise caused by other factors, and obtain the in-vehicle background noise; A target classification module is used to calculate the characteristic loudness of the corresponding interior background noise under various driving conditions of the vehicle, and to classify the interior intake order noise based on the characteristic loudness of the interior background noise; The module for simulating the air intake order noise of the air intake port is used to simulate the air intake order noise of the air intake port at the air intake port so that the frequency and amplitude of the air intake order noise transmitted into the vehicle are the same as the frequency and amplitude of the air intake order noise of the vehicle at the corresponding levels of targets; The air inlet order noise target classification setting module obtains the simulated air inlet order noise and performs the air inlet order noise target classification setting according to the simulated air inlet order noise.

9. The device for setting the target classification of inlet order noise based on a harmonic signal generator according to claim 8, characterized in that: The noise separation module also includes: The silencer module silences the vehicle's air intake port and eliminates the intake order noise inside the vehicle, thereby obtaining the background noise inside the vehicle caused by other factors inside the vehicle.

10. The device for setting the target classification of inlet order noise based on harmonic signal generator according to claim 1, characterized in that: A module that simulates the inlet order noise of the air intake, including: A harmonic signal generator generates a harmonic sounder at the engine order noise frequency, and emits a simulated intake order noise through the harmonic sounder; The regulating module is used to regulate the frequency and amplitude of the simulated air intake order noise emitted by the harmonic signal generator, so that the frequency and amplitude of the simulated air intake order noise are the same as the frequency and amplitude of the in-vehicle air intake order noise of the corresponding levels of targets.

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