Vehicle noise test method, system, and vehicle

Abstract

This disclosure provides a vehicle noise testing method and system, applicable to the field of rail transit technology. The method includes: determining the tunnel sound field simulation conditions of the airtight test bench based on the differences in spatial and acoustic parameters between the airtight test bench and the tunnel to be simulated; constructing a sound field simulation test environment that matches the tunnel sound field simulation conditions; the sound field simulation test environment includes a noise control system, multiple noise playback sources, and multiple sensors; adjusting the wheel-rail noise playback signal through the noise control system based on the difference between the pre-collected wheel-rail noise spectrum of the actual tunnel line and the playback spectrum within the airtight test bench; forming a simulated tunnel sound field based on the adjusted wheel-rail noise playback signal using multiple noise playback sources; and collecting noise data of the tested rail vehicle under the simulated tunnel sound field using multiple sensors to obtain the noise distribution corresponding to the tested rail vehicle.

Description

Technical Field

[0001] This disclosure relates to the field of train technology, and more specifically, to a vehicle noise testing method, system, and vehicle. Background Technology

[0002] With the development and widespread use of rail vehicles, noise testing is typically required before they are put into actual operation. Rail vehicle tunnel noise testing usually employs either actual line testing or laboratory simulation testing. Actual line testing is limited by operational organization, testing time slots, and experimental conditions, resulting in long testing cycles and inconvenience for repeated testing. While laboratory simulation testing can be conducted in a controlled environment, the test space may differ from the actual tunnel in terms of spatial constraints and acoustic response. Furthermore, laboratory sound field simulations have limited accuracy in reproducing the wheel-rail noise spectrum of actual lines, and the replayed sound field may deviate from the actual tunnel noise characteristics, thus affecting the accuracy and representativeness of the rail vehicle noise distribution test results. Summary of the Invention

[0003] In view of this, the present disclosure provides a vehicle noise testing method, a vehicle noise testing system, and a vehicle.

[0004] One aspect of this disclosure provides a vehicle noise testing method, comprising: determining the tunnel sound field simulation conditions of the airtight test bench based on the differences in spatial parameters and acoustic parameters between the airtight test bench and the tunnel to be simulated; constructing a sound field simulation test environment that matches the tunnel sound field simulation conditions; the sound field simulation test environment includes a noise control system, multiple noise playback sources, and multiple sensors; adjusting the wheel-rail noise playback signal through the noise control system based on the difference between the pre-collected wheel-rail noise spectrum of the actual tunnel line and the playback spectrum in the airtight test bench; forming a simulated tunnel sound field based on the adjusted wheel-rail noise playback signal through multiple noise playback sources; and acquiring the noise data of the tested rail vehicle under the simulated tunnel sound field through multiple sensors to obtain the noise distribution of the tested rail vehicle.

[0005] Another aspect of this disclosure provides a vehicle noise testing system, comprising: an airtight test bench; a noise control system for adjusting the wheel-rail noise playback signal based on the difference between the pre-acquired wheel-rail noise spectrum of an actual tunnel line and the playback spectrum within the airtight test bench; multiple noise playback sources connected to the noise control system for forming a simulated tunnel sound field within the airtight test bench based on the adjusted wheel-rail noise playback signal; and multiple sensors for acquiring playback noise data within the airtight test bench and noise data of the tested rail vehicle under the simulated tunnel sound field; wherein the playback spectrum is the spectrum corresponding to the playback noise data, and the noise data of the tested rail vehicle is used to obtain the noise distribution of the tested rail vehicle; wherein the airtight test bench, the noise control system, the multiple noise playback sources, and the multiple sensors together constitute a sound field simulation test environment matching the tunnel sound field simulation conditions, and the tunnel sound field simulation conditions are determined based on the differences in spatial parameters and acoustic parameters between the airtight test bench and the tunnel to be simulated.

[0006] Another aspect of this disclosure provides a vehicle including the vehicle noise testing system described in the foregoing embodiments.

[0007] According to embodiments of this disclosure, by constructing a sound field simulation test environment based on the differences in spatial and acoustic parameters between the airtight test bench and the tunnel to be simulated, and adjusting the wheel-rail noise playback signal according to the difference between the actual tunnel track wheel-rail noise spectrum and the playback spectrum, the matching degree between the simulated tunnel sound field and the actual tunnel sound field can be improved, the spectral deviation between the playback noise and the actual track wheel-rail noise can be reduced, and the reproducibility of the actual track wheel-rail noise can be improved. On this basis, by collecting noise data of the track vehicle under test through multiple sensors, the noise distribution corresponding to the track vehicle under test can be obtained under controllable and repeatable test conditions, reducing the dependence of the track vehicle tunnel noise test on the actual track test conditions. Attached Figure Description

[0008] The above and other objects, features and advantages of this disclosure will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0009] Figure 1 A flowchart illustrating a vehicle noise testing method according to an embodiment of the present disclosure is shown schematically.

[0010] Figure 2 A block diagram of a vehicle noise testing system according to an embodiment of the present disclosure is shown schematically;

[0011] Figure 3 This schematically illustrates the hardware connection and noise playback test link diagram of a noise control system according to an embodiment of the present disclosure;

[0012] Figure 4The diagram schematically illustrates the arrangement of noise measurement points inside and outside the vehicle and the noise playback source according to an embodiment of the present disclosure; and

[0013] Figure 5 A block diagram of a control computer in a noise control system according to an embodiment of the present disclosure is shown schematically. Detailed Implementation

[0014] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0015] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0016] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0017] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0018] In the embodiments disclosed herein, the collection, updating, analysis, processing, use, transmission, provision, disclosure, and storage of data (e.g., including but not limited to user personal information) comply with relevant laws and regulations, are used for legitimate purposes, and do not violate public order and good morals. In particular, necessary measures have been taken to prevent unauthorized access to user personal information data and to maintain user personal information security and network security.

[0019] In the embodiments disclosed herein, user authorization or consent is obtained before acquiring or collecting user personal information.

[0020] In realizing the inventive concept of this disclosure, in related technologies, the tunnel noise test of rail vehicles can be carried out by mainline tunnel testing or laboratory simulation testing. Among them, mainline tunnel testing obtains the noise characteristics of the vehicle in the tunnel environment by collecting noise data during the operation of the rail vehicle in an actual tunnel environment; laboratory simulation testing can form a sound field in the test space through a sound source and use sensors to collect noise data at different positions of the vehicle.

[0021] Specifically, noise testing in a mainline tunnel environment requires scheduling the test time in conjunction with the line's operational status and collecting noise data inside and outside the vehicle during operation. Because mainline tunnel testing is limited by factors such as line operating time, test organization, and testing conditions, the testing cycle is relatively long, and it is difficult to frequently conduct repeated tests according to different testing needs during vehicle development. While laboratory simulation testing can conduct noise testing under relatively controllable conditions, it typically uses excitation signals such as white noise to create a simulated sound field, without fully considering the differences in cross-sectional dimensions and reverberation time between the test space and the actual tunnel. Therefore, the resulting sound field may differ from the actual tunnel sound field.

[0022] Furthermore, the noise generated by rail vehicles operating in actual tunnels exhibits spectral characteristics related to the vehicle's operating state and the interaction between the wheel and rail. When using conventional excitation signals for sound field simulation, it is difficult to directly reproduce the wheel-rail noise spectrum collected from the actual line, and it is also difficult to independently adjust the sound pressure level for different frequency bands. When there is a difference between the playback spectrum in the test bench and the wheel-rail noise spectrum collected from the actual line, it further leads to a deviation between the noise distribution in the simulated sound field and the noise distribution in the actual tunnel environment, thus affecting the test results of the noise distribution inside and outside the vehicle.

[0023] Meanwhile, if noise is only collected at local locations on the vehicle, it is difficult to reflect the distribution of noise along the vehicle's longitudinal direction and in different areas such as the undercarriage, side walls, and roof under the simulated tunnel sound field. This is not conducive to obtaining data on the vehicle's internal and external noise distribution in a tunnel environment. Search results indicate that while some related technologies involve setting up multiple test sections along the vehicle and conducting noise tests on multiple vehicle body areas, a complete technical solution combining equivalent sound field measurements from an airtight test bench, actual track wheel-rail noise playback, and multi-location noise collection has not yet been developed.

[0024] As mentioned above, the related technologies suffer from several problems, including insufficient equivalence between the laboratory test space and the actual tunnel sound field, difficulty in accurately reproducing the actual track wheel-rail noise spectrum, and difficulty in obtaining vehicle noise distribution under controllable test conditions. In view of this, embodiments of this disclosure provide a vehicle noise testing method and system. The method determines the tunnel sound field simulation conditions based on the differences in spatial and acoustic parameters between the airtight test bench and the tunnel to be simulated, and constructs a sound field simulation test environment that matches the tunnel sound field simulation conditions. The method adjusts the wheel-rail noise playback signal according to the difference between the pre-collected actual tunnel track wheel-rail noise spectrum and the playback spectrum within the airtight test bench. A simulated tunnel sound field is formed through multiple noise playback sources, and noise data of the tested track vehicle under the simulated tunnel sound field is collected through multiple sensors to obtain the noise distribution corresponding to the tested track vehicle.

[0025] Figure 1 A flowchart illustrating a vehicle noise testing method according to an embodiment of the present disclosure is shown schematically.

[0026] like Figure 1 As shown, the vehicle noise testing method of this embodiment includes: operations S110~S150.

[0027] In operation S110, based on the differences in spatial and acoustic parameters between the airtight test rig and the tunnel to be simulated, the tunnel acoustic field simulation conditions of the airtight test rig are determined. The airtight test rig can be an acoustic test space constrained by spatial boundaries, used to accommodate the track vehicle under test. The tunnel to be simulated can be the actual tunnel environment that serves as the object of acoustic field simulation. Spatial parameters characterize the spatial constraint characteristics of both the airtight test rig and the tunnel to be simulated, while acoustic parameters characterize the acoustic field response characteristics within the corresponding spaces. The tunnel acoustic field simulation conditions can be understood as the test conditions used when simulating the acoustic field of the tunnel to be simulated using the airtight test rig.

[0028] Specifically, the spatial and acoustic parameters of the airtight test bench and the tunnel to be simulated can be obtained separately. The differences between the two in terms of spatial and acoustic characteristics can be compared, and the test conditions that match the sound field of the tunnel to be simulated can be determined based on the comparison results. Therefore, the airtight test bench is not directly used as the tunnel environment, but rather the test conditions suitable for tunnel sound field simulation are determined first in combination with the actual characteristics of the tunnel to be simulated.

[0029] In operation S120, a sound field simulation test environment matching the tunnel sound field simulation conditions is constructed. This environment includes a noise control system, multiple noise playback sources, and multiple sensors. The sound field simulation test environment can be understood as a test environment comprised of noise signal control, acoustic output, and noise acquisition under the aforementioned tunnel sound field simulation conditions. Specifically, the noise control system controls and adjusts the noise signal to be played back; the noise playback sources convert the corresponding noise playback signals into acoustic outputs; and the sensors acquire noise information within the test space.

[0030] When constructing a sound field simulation test environment, noise playback sources and sensors can be configured within the airtight test bench, and a signal transmission relationship can be established between the noise control system and the noise playback sources. This allows noise signal adjustment, acoustic playback, and noise acquisition to be performed under the same tunnel sound field simulation conditions. All components together form a test environment within the airtight test bench for reproducing the tunnel noise environment and conducting vehicle noise tests.

[0031] In operation S130, based on the difference between the pre-acquired wheel-rail noise spectrum of the actual tunnel line and the playback spectrum within the airtight test rig, the wheel-rail noise playback signal is adjusted by the noise control system. The actual tunnel line wheel-rail noise spectrum can be a frequency domain representation obtained from pre-acquired wheel-rail noise data during the operation of the rail vehicle on the actual tunnel line, used to reflect the distribution characteristics of wheel-rail noise with frequency in the actual tunnel environment. The playback spectrum can be understood as the spectral information characterizing the wheel-rail noise playback result within the airtight test rig. The wheel-rail noise playback signal can be the input signal used to drive the noise playback source to generate wheel-rail noise.

[0032] Specifically, the pre-collected wheel-rail noise spectrum of the actual tunnel line is used as a playback reference. The actual wheel-rail noise spectrum of the tunnel line is compared with the playback spectrum in the airtightness test bench, and the wheel-rail noise playback signal is adjusted according to the spectral deviation between the two, so that the adjusted playback result is closer to the spectral characteristics of the actual tunnel line wheel-rail noise. Here, a general noise unrelated to the actual wheel-rail noise collected from the line is not directly used as the sound field excitation, but the pre-collected wheel-rail noise spectrum in the actual tunnel line is used as the reference for noise playback and adjustment.

[0033] In operation S140, a simulated tunnel sound field is formed based on the adjusted wheel-rail noise playback signal from multiple noise playback sources. The simulated tunnel sound field can be understood as a sound field characterizing the wheel-rail noise environment of the tunnel to be simulated, formed by the acoustic output of multiple noise playback sources within an airtight test bench. This sound field is established under the aforementioned tunnel sound field simulation conditions and uses the adjusted wheel-rail noise playback signal as the acoustic excitation.

[0034] Specifically, multiple noise playback sources generate corresponding acoustic outputs based on the adjusted wheel-rail noise playback signals. The acoustic signals generated by each noise playback source jointly form a sound field within the test space of the airtight test bench, so that the formed simulated tunnel sound field is simultaneously constrained by the aforementioned tunnel sound field simulation conditions and the actual track wheel-rail noise spectrum characteristics.

[0035] During operation of S150, noise data of the track vehicle under test is collected through multiple sensors under a simulated tunnel sound field, obtaining the noise distribution corresponding to the track vehicle under test. The noise data can be acoustic measurement data that characterizes the noise state at the corresponding test location. The noise distribution can be understood as the noise characteristics and spatial variation relationship of the track vehicle at different test locations, used to characterize the noise situation at different locations when the vehicle is in a simulated tunnel sound field.

[0036] In a simulated tunnel acoustic field, noise data at corresponding test locations of the track vehicle under test is acquired using multiple sensors, and a correlation is established between the test locations of each sensor and the collected noise data. Based on the noise data at different test locations, the variation of noise at different positions of the track vehicle under test can be obtained, thus revealing the noise distribution of the track vehicle under test.

[0037] According to embodiments of this disclosure, the tunnel sound field simulation conditions are first determined based on the differences in spatial and acoustic characteristics between the airtight test bench and the tunnel to be simulated. Then, the wheel-rail noise spectrum pre-collected from the actual tunnel line is used as a reference for noise playback. The wheel-rail noise playback signal is adjusted according to the deviation between the actual tunnel line wheel-rail noise spectrum and the playback spectrum in the airtight test bench. Multiple noise playback sources form a simulated tunnel sound field within the airtight test bench. Compared to directly using general noise for sound field excitation in the test space, this method considers both the differences between the test space and the tunnel to be simulated, as well as the spectral characteristics of the actual line wheel-rail noise. This reduces the difference between the laboratory simulated sound field and the actual tunnel sound field, and decreases the spectral deviation between the playback noise and the actual line wheel-rail noise. Furthermore, by collecting noise data from multiple sensors on the tested rail vehicle, the noise distribution of the vehicle can be obtained under controllable test conditions, thereby reducing the dependence of vehicle tunnel noise testing on actual operating line test conditions.

[0038] According to embodiments of this disclosure, the spatial parameter differences include the difference in cross-sectional dimensions between the airtight test bench and the tunnel to be simulated; the acoustic parameter differences include the difference in reverberation time between the airtight test bench and the tunnel to be simulated. The difference in cross-sectional dimensions characterizes the difference in the transverse cross-sectional geometry between the airtight test bench and the tunnel to be simulated, reflecting the difference in spatial constraints they impose on the sound field formation. The difference in reverberation time characterizes the difference in sound field attenuation characteristics between the airtight test bench and the tunnel to be simulated, reflecting the difference in sound energy attenuation over time within the corresponding space.

[0039] Specifically, the cross-sectional dimensions of the airtightness test bench can be compared with those of the tunnel to be simulated to obtain the corresponding cross-sectional dimension differences. Furthermore, the reverberation times of both the airtightness test bench and the tunnel to be simulated can be obtained and compared to obtain the corresponding reverberation time differences. These cross-sectional dimension differences and reverberation time differences serve together as parameters for evaluating the differences in the acoustic environment between the airtightness test bench and the tunnel to be simulated.

[0040] For example, the transverse cross-sectional dimensions and reverberation time of the airtight test bench and the tunnel to be simulated can be obtained respectively. The differences in cross-sectional dimensions and reverberation time can be obtained based on the differences between similar parameters, and the two types of differences can be used as parameters to evaluate the matching relationship between the two sound field environments.

[0041] According to the embodiments of this disclosure, the difference in cross-sectional dimensions characterizes the difference in spatial geometric constraints between the airtight test bench and the tunnel to be simulated, and the difference in reverberation time characterizes the difference in sound field attenuation characteristics between the two. This allows the determination of tunnel sound field simulation conditions to take into account both the geometric characteristics and acoustic response characteristics of the test space, reducing environmental matching deviations caused by determining simulation conditions based on only a single spatial parameter or a single acoustic parameter, thereby improving the degree of matching between the airtight test bench and the tunnel to be simulated in terms of sound field environment.

[0042] According to embodiments of this disclosure, the tunnel acoustic field simulation conditions of the airtight test bench are determined based on the differences in spatial and acoustic parameters between the airtight test bench and the tunnel to be simulated. This includes: determining the cross-sectional dimensions of the airtight test bench based on the differences in cross-sectional dimensions; determining the difference in reverberation time between the airtight test bench in the open and closed states and the reverberation time of the tunnel to be simulated; and determining the end-door state with the smaller difference between the reverberation time in the open and closed states and the reverberation time of the tunnel to be simulated as the tunnel acoustic field simulation condition.

[0043] The state of the end doors can affect the attenuation process of acoustic energy inside the airtight test rig, resulting in different reverberation times for different end door states. Based on the aforementioned differences in cross-sectional dimensions, the cross-sectional dimensions of the airtight test rig that match the spatial constraint characteristics of the tunnel to be simulated can be determined. Furthermore, by comparing the differences between the reverberation times under different end door states and the reverberation times of the tunnel to be simulated, the degree of similarity between the sound field attenuation characteristics corresponding to different end door states and the tunnel to be simulated can be further evaluated.

[0044] Specifically, the cross-sectional dimensions of the airtightness test bench can be determined first based on the difference between the cross-sectional dimensions of the tunnel to be simulated and the cross-sectional dimensions of the airtightness test bench. Then, the reverberation times of the airtightness test bench are obtained for both the open and closed end-door states, and these reverberation times are compared with the reverberation time of the tunnel to be simulated. The smaller the difference in reverberation time between the end-door states, the closer the sound field attenuation characteristics of the airtightness test bench are to the tunnel to be simulated under that end-door state. Therefore, the end-door state with the smaller reverberation time difference can be used as the end-door state for tunnel sound field simulation.

[0045] For example, the cross-sectional dimensions of the airtight test bench and the tunnel to be simulated can be checked first. The cross-sectional dimensions of the airtight test bench used for sound field simulation can be determined based on the difference between the two. For reverberation time, the steady-state sound source truncation method can be used for measurement. An omnidirectional sound source is placed inside the track of the airtight test bench, and five sensors are placed in the middle cross-section of the test. After the sound source forms a stable sound field, the acoustic excitation is stopped, and the reverberation time is obtained based on the sound field decay process. In one specific implementation, the reverberation time in the frequency range of 100Hz to 5000Hz can be measured separately in the open and closed states of the end door, and compared with the reverberation time in the corresponding frequency range of the tunnel to be simulated. In the test results, the deviation between the reverberation time of the airtight test bench in the open state and the reverberation time of the tunnel to be simulated can be no more than 10%, and the difference is smaller than that in the closed state. In this case, the open state of the end door can be determined as the tunnel sound field simulation condition.

[0046] According to the embodiments of this disclosure, the cross-sectional dimensions of the airtight test bench that match the spatial constraint characteristics of the tunnel to be simulated are first determined by the difference in cross-sectional dimensions. Then, the reverberation time difference between the airtight test bench and the tunnel to be simulated is compared under different end door states. The end door state with a smaller reverberation time difference is selected as the tunnel sound field simulation condition. This makes the selection of simulation conditions subject to both spatial geometric characteristics and sound field attenuation characteristics, thereby making the sound field environment formed by the airtight test bench closer to the sound field environment corresponding to the tunnel to be simulated.

[0047] According to embodiments of this disclosure, the plurality of noise playback sources include a plurality of dodecahedral sound sources; the construction of a sound field simulation test environment matching the tunnel sound field simulation conditions includes: arranging at least one of the dodecahedral sound sources at the axle positions corresponding to each bogie region of the track vehicle under test. In one embodiment, the plurality of noise playback sources include four dodecahedral sound sources; the construction of a sound field simulation test environment matching the tunnel sound field simulation conditions includes: arranging four dodecahedral sound sources at the four axle positions corresponding to the two bogie regions of the track vehicle under test. The four axle positions are respectively located in the two bogie regions of the track vehicle under test. Wheel-rail noise is mainly generated at the wheel-rail contact position; therefore, arranging the noise playback sources at positions corresponding to the axles allows the noise playback positions to correspond to the areas where wheel-rail noise is generated during actual vehicle operation.

[0048] Specifically, dodecahedral sound sources can be arranged at the two axle positions corresponding to each bogie area, so that the two bogie areas correspond to a total of four dodecahedral sound sources. During noise playback, the four dodecahedral sound sources generate acoustic outputs based on the wheel-rail noise playback signal, and together form a wheel-rail noise sound field from different axle positions along the longitudinal direction of the vehicle, so as to characterize the spatial distribution of wheel-rail noise in the bogie area.

[0049] For example, to simulate the tunnel wheel-rail noise at a speed of 80 km / h for rail vehicles, a dodecahedral sound source can be placed at each of the four axle positions corresponding to the two bogie areas under the vehicle, for a total of four dodecahedral sound sources. The tunnel wheel-rail noise at the corresponding speed level can be played back using the four dodecahedral sound sources to restore the wheel-rail noise distribution in the bogie area.

[0050] According to the embodiments of this disclosure, by arranging dodecahedral sound sources at the four axle positions corresponding to the two bogie areas, the noise playback position corresponds to the actual generation area of ​​wheel-rail noise. Compared with the method of arranging sound sources without considering the position of wheel-rail noise sources, the spatial difference between the noise playback position and the actual generation position of wheel-rail noise can be reduced, which is beneficial to reproducing the wheel-rail noise distribution in the bogie area in the airtight test bench.

[0051] According to embodiments of this disclosure, the multiple sensors include multiple target control point sensors and multiple monitoring point sensors; constructing a sound field simulation test environment that matches the tunnel sound field simulation conditions includes: arranging multiple target control point sensors in the bogie area of ​​the track vehicle under test at locations corresponding to the actual track spectrum of the line; and arranging multiple monitoring point sensors in the undercarriage area, side wall area, and roof area of ​​the middle and both ends of the track vehicle under test.

[0052] The target control point sensor can be a sensor positioned corresponding to the actual track spectrum acquisition location, used to collect playback noise data at that location; the monitoring point sensor can be a sensor positioned in different spatial areas of the track vehicle under test, used to collect noise data for the corresponding area. The actual track spectrum location can be understood as the spatial location corresponding to the actual track wheel-rail noise acquisition.

[0053] A spatial correspondence is established between the target control point sensors and the actual track spectrum locations, enabling the playback noise data collected in the airtightness test bench to have a corresponding spatial reference with the wheel-rail noise data collected on the actual track. The monitoring point sensors are distributed in the middle and both ends of the vehicle body, covering the undercarriage area, side wall area, and roof area, thereby enabling the collection of noise data at different longitudinal positions and in different spatial areas of the vehicle.

[0054] For example, target control point sensors can be placed in the bogie area of ​​the track vehicle under test, corresponding to the actual wheel-rail noise collection locations on the track. Simultaneously, monitoring point sensors can be placed in the undercarriage area, sidewall area, and roof area at the center and both ends of the vehicle body, respectively. During noise testing, the target control point sensors collect playback noise data corresponding to the actual track locations, while the monitoring point sensors collect noise data for their respective monitored areas, thus forming a noise collection layout consisting of target control points and monitoring points.

[0055] According to the embodiments of this disclosure, by dividing the sensors into target control point sensors and monitoring point sensors, and establishing the correspondence between the target control point sensors and the actual road spectrum positions of the line, and between the monitoring point sensors and different spatial regions of the vehicle, the replay noise data and the actual road noise data have corresponding spatial references. At the same time, it is possible to obtain noise information of different longitudinal positions and different regions of the vehicle, and provide corresponding measurement data for evaluating the noise playback situation and vehicle noise distribution under the simulated tunnel sound field.

[0056] According to an embodiment of this disclosure, the noise control system includes a digital audio processor; adjusting the wheel-rail noise playback signal through the noise control system includes: adjusting the amplitude of multiple frequency bands corresponding to the wheel-rail noise playback signal respectively through the digital audio processor; wherein the amplitude adjustment range of each frequency band is ±15dB. The multiple frequency bands can be multiple frequency intervals obtained by dividing the wheel-rail noise playback signal according to frequency. Adjusting the amplitude of multiple frequency bands separately allows different frequency intervals to have independent amplitude adjustment capabilities.

[0057] Specifically, the amplitude adjustment parameters corresponding to different frequency bands can be set separately by a digital audio processor, so that the frequency band that needs to increase the sound pressure level increases the corresponding amplitude, and the frequency band that needs to decrease the sound pressure level decreases the corresponding amplitude, without having to make each frequency band change synchronously with the same amplitude, thereby adjusting the spectral shape of the wheel-rail noise playback signal by frequency band.

[0058] For example, in one specific implementation, the total sound pressure level of the sound source can be adjusted to 100dB, the actual value measured on the line, and then the wheel-rail noise playback signal can be divided into 17 1 / 3 octave bands. The amplitude of each of the 17 bands can be adjusted by a digital audio processor, and the amplitude adjustment range of each band is ±15dB.

[0059] According to the embodiments of this disclosure, by dividing the wheel-rail noise playback signal into multiple frequency bands and adjusting the amplitude of each frequency band separately, the sound pressure level in different frequency regions can be independently corrected, reducing the problem that the spectral deviation of different frequency regions cannot be corrected separately when only the overall sound pressure level is adjusted, thereby improving the matching degree between the wheel-rail noise playback spectrum and the actual line wheel-rail noise spectrum.

[0060] According to embodiments of this disclosure, adjusting the wheel-rail noise playback signal through a noise control system includes: determining the gain adjustment amount corresponding to each frequency band based on the difference between the wheel-rail noise spectrum and the playback spectrum; and performing iterative gain adjustment on each frequency band according to the gain adjustment amount corresponding to each frequency band. The gain adjustment amount can be a signal gain change determined based on the difference between the wheel-rail noise spectrum and the playback spectrum of the corresponding frequency band, used to adjust the amplitude of the playback signal corresponding to that frequency band. Iterative gain adjustment can be understood as performing multiple gain adjustments on each frequency band based on the spectral difference, and obtaining the playback spectrum again after each adjustment to update the spectral difference of the corresponding frequency band.

[0061] The system compares the wheel-rail noise spectrum with the playback spectrum for each frequency band to obtain the corresponding spectral difference. Based on this difference, the appropriate gain adjustment is determined. After one gain adjustment, the playback spectrum is obtained again, and the spectral difference is recalculated. The gain of the corresponding frequency band is then adjusted until the spectral difference for each band reaches the preset error range. Each frequency band is adjusted according to its own spectral difference, thereby gradually reducing the local spectral deviation between the wheel-rail noise spectrum and the playback spectrum.

[0062] For example, after a noise playback, the playback spectrum corresponding to each frequency band can be obtained. The playback spectrum of each frequency band can be compared with the pre-acquired wheel-rail noise spectrum, and the gain of the corresponding frequency band can be adjusted according to the spectral difference obtained from the comparison. After the adjustment is completed, noise playback and spectrum comparison can be performed again, and the above process can be repeated. In one specific implementation, the corresponding gain iterative adjustment can be stopped after the spectral error of each frequency band is controlled within 1dB.

[0063] According to the embodiments of this disclosure, by calculating the difference between the wheel-rail noise spectrum and the playback spectrum of each frequency band, and performing gain iterative adjustment on each frequency band based on the corresponding difference, the playback deviation of different frequency regions can be continuously corrected, so that the playback spectrum of each frequency band gradually approaches the corresponding wheel-rail noise spectrum, thereby reducing the spectral error generated when the actual wheel-rail noise of the line is played back in the airtight test bench, and improving the reproduction degree of the wheel-rail noise spectrum.

[0064] According to an embodiment of this disclosure, noise data of a track vehicle under test is collected using multiple sensors in a simulated tunnel sound field. This includes: selecting multiple test sections along the longitudinal direction of the track vehicle under test; arranging sensors in the undercarriage area, side wall area, and roof area corresponding to each test section; collecting multiple sets of noise sound pressure level data for each test section; and calculating the average value of the multiple sets of noise sound pressure level data for the same test section as the noise data corresponding to the test section.

[0065] The test section can be a transverse test location selected along the longitudinal direction of the track vehicle under test, used to characterize the noise state at the corresponding longitudinal position. By collecting noise data at different test sections and in the undercarriage, sidewall, and roof areas of the same test section, noise sound pressure level data corresponding to different longitudinal positions of the vehicle and different areas of the same section can be obtained.

[0066] Multiple test sections can be selected at longitudinal intervals along the track vehicle under test, with noise measurement points set at the undercarriage, sidewall, and roof regions of each section. For the same test section, noise data can be collected repeatedly, and the average of multiple sets of noise sound pressure level data can be taken to reduce the impact of single measurement fluctuations on the noise data of the test section. The noise data corresponding to different test sections can be used to characterize the variation of noise along the longitudinal direction of the vehicle, and the noise data corresponding to different regions can be used to characterize the differences in noise distribution between the undercarriage, sidewall, and roof.

[0067] For example, three test sections can be selected at the end, quarter-body position, and middle of the tested rail vehicle. Sensors are placed at the center of the undercarriage, the height of the side wall windows, and the center of the roof at each test section. Under simulated tunnel sound field conditions, three sets of noise sound pressure level data are collected for each test section, and the average of the three sets of noise sound pressure level data is taken as the noise data for the corresponding test section. Based on the noise data from different test sections and different areas, the noise variation from the bogie area to the middle of the undercarriage, as well as the noise distribution between the undercarriage, side walls, and roof, can be compared.

[0068] According to the embodiments of this disclosure, by setting multiple test sections along the longitudinal direction of the vehicle and collecting noise data in the undercarriage area, side wall area, and roof area of ​​each test section, noise information can be obtained from two spatial dimensions: the longitudinal position of the vehicle and different areas of the vehicle body. At the same time, averaging multiple sets of noise sound pressure level data from the same test section can reduce the impact of accidental measurement fluctuations on the test results and improve the stability of noise data from each test section, thereby more accurately characterizing the noise distribution of the track vehicle under the simulated tunnel sound field.

[0069] The following describes the composition of the vehicle noise testing system and the functional relationships between its components, using examples of the aforementioned vehicle noise testing methods.

[0070] Figure 2 A block diagram of a vehicle noise testing system according to an embodiment of the present disclosure is shown schematically.

[0071] like Figure 2 As shown, the vehicle noise testing system may include an airtight test bench; a noise control system for adjusting the wheel-rail noise playback signal based on the difference between the pre-collected actual tunnel track wheel-rail noise spectrum and the playback spectrum within the airtight test bench; multiple noise playback sources connected to the noise control system for forming a simulated tunnel sound field within the airtight test bench based on the adjusted wheel-rail noise playback signal; and multiple sensors for collecting playback noise data within the airtight test bench and noise data of the track vehicle under test under the simulated tunnel sound field. The playback spectrum is the spectrum corresponding to the playback noise data, and the noise data of the track vehicle under test is used to obtain the noise distribution corresponding to the track vehicle under test. The airtight test bench, the noise control system, the multiple noise playback sources, and the multiple sensors together constitute a sound field simulation test environment matching the tunnel sound field simulation conditions, which are determined based on the differences in spatial and acoustic parameters between the airtight test bench and the tunnel to be simulated.

[0072] The airtight test bench serves as a physical test space to accommodate the track vehicle under test and create a simulated tunnel sound field. The noise control system, as the control part for noise playback, adjusts the wheel-rail noise playback signal input to the noise playback source; multiple noise playback sources, as the acoustic output part, convert the adjusted wheel-rail noise playback signal into acoustic output; multiple sensors, as the noise acquisition part, respectively acquire playback noise data to characterize the playback results and noise data to characterize the noise state of the track vehicle under test.

[0073] The noise control system establishes signal transmission relationships with multiple noise playback sources, which, along with multiple sensors, are positioned within the test space formed by the airtight test bench. After determining the tunnel sound field simulation conditions based on the spatial and acoustic parameter differences between the airtight test bench and the tunnel to be simulated, each component works in coordination under these simulation conditions. The noise control system adjusts the wheel-rail noise playback signal according to the difference between the actual tunnel track wheel-rail noise spectrum and the playback spectrum. The noise playback sources form a simulated tunnel sound field based on the adjusted signal, and the sensors collect the corresponding noise data. The specific signal adjustment, sound field formation, and noise data acquisition processes can be referenced from operations S110 to S150 in the aforementioned vehicle noise testing method embodiment.

[0074] For example, the track vehicle under test can be placed in a test space formed by an airtight test bench, and a sound field simulation test environment can be constructed by a noise control system, multiple noise playback sources, and multiple sensors. The noise control system receives and adjusts the wheel-rail noise signal for playback, and transmits the adjusted wheel-rail noise playback signal to multiple noise playback sources; the multiple noise playback sources perform noise playback within the airtight test bench; and multiple sensors collect playback noise data and noise data of the track vehicle under test, respectively. The playback spectrum obtained based on the playback noise data can be used to characterize the current noise playback status, and the noise distribution under the simulated tunnel sound field can be obtained based on the noise data of the track vehicle under test.

[0075] According to the embodiments of this disclosure, a physical test space for sound field simulation is provided by an airtight test bench. The noise control system adjusts the wheel-rail noise playback signal according to the difference between the actual tunnel line wheel-rail noise spectrum and the playback spectrum. Multiple noise playback sound sources form a simulated tunnel sound field. Multiple sensors are used to collect playback noise data and vehicle noise data. The tunnel sound field simulation, line wheel-rail noise playback, and vehicle noise testing can be integrated into the same test environment, reducing the dependence of vehicle tunnel noise testing on actual line test conditions, and obtaining the noise distribution corresponding to the tested track vehicle under controllable test conditions.

[0076] According to embodiments of this disclosure, the spatial parameter differences include the difference in cross-sectional dimensions between the airtight test bench and the tunnel to be simulated; the acoustic parameter differences include the difference in reverberation time between the airtight test bench and the tunnel to be simulated. The difference in cross-sectional dimensions characterizes the difference between the airtight test bench and the tunnel to be simulated in terms of spatial geometric constraints, while the difference in reverberation time characterizes the difference between the two in terms of sound field attenuation characteristics. For the specific meanings and determination methods of the differences in cross-sectional dimensions and reverberation time, please refer to the relevant descriptions in the foregoing method embodiments.

[0077] In this embodiment, the difference in cross-sectional dimensions and the difference in reverberation time can be used as two types of parameters when matching the sound field simulation test environment with the tunnel to be simulated. Therefore, the test space provided by the airtight test bench not only considers the spatial scale difference between itself and the tunnel to be simulated, but also the acoustic response difference of their corresponding sound fields.

[0078] For example, when constructing a sound field simulation test environment, the corresponding tunnel sound field simulation conditions can be determined simultaneously based on the differences in cross-sectional dimensions and reverberation time between the airtight test bench and the tunnel to be simulated. This allows the airtight test bench, noise control system, multiple noise playback sources, and multiple sensors to constitute the sound field simulation test environment under these tunnel sound field simulation conditions. Specific methods for comparing cross-sectional dimensions and reverberation time can be found in the relevant content of the aforementioned method embodiments.

[0079] According to the embodiments of this disclosure, by using both cross-sectional size differences and reverberation time differences as matching criteria for the sound field simulation test environment, the test environment formed by the airtight test bench can take into account the spatial geometric characteristics and sound field attenuation characteristics of the tunnel to be simulated, reducing the deviation caused by constructing the simulation environment based on only a single type of parameter, and making the sound field simulation test environment closer to the sound field conditions of the tunnel to be simulated.

[0080] According to an embodiment of this disclosure, the noise control system includes a control computer, a digital audio processor, a signal distributor, and a power amplifier connected in sequence; the power amplifier is connected to multiple noise playback sources. The control computer can serve as the control terminal of the noise control system, used to load wheel-rail noise playback signals and perform related control; the digital audio processor can process the received wheel-rail noise playback signals; the signal distributor can distribute the processed wheel-rail noise playback signals to corresponding signal transmission paths; the power amplifier can amplify the power of the distributed wheel-rail noise playback signals and output the amplified signals to the corresponding noise playback sources.

[0081] The wheel-rail noise playback signal sequentially passes through a control computer, digital audio processor, signal distributor, and power amplifier before being transmitted to multiple noise playback sources, thus forming a noise playback chain from noise signal loading, signal processing, signal distribution, power amplification to acoustic output. The noise control system adjusts the wheel-rail noise playback signal based on the difference between the wheel-rail noise spectrum and the playback spectrum.

[0082] For example, in one implementation, a control computer can load pre-collected track wheel-rail noise data and send the corresponding wheel-rail noise playback signal to a digital audio processor. After processing the signal, the digital audio processor transmits the signal to a power amplifier via a signal distributor, and the power amplifier then drives the corresponding noise playback source for noise playback. The digital audio processor can support up to eight outputs to provide multi-channel noise signal output capability. For details of the process, please refer to the relevant descriptions in the foregoing method embodiments.

[0083] According to embodiments of this disclosure, by sequentially connecting a control computer, a digital audio processor, a signal distributor, and a power amplifier, and connecting the power amplifier to multiple noise playback sources, a noise playback link with signal loading, signal processing, signal distribution, and power amplification functions can be formed. This allows the regulated wheel-rail noise playback signal to be transmitted to the corresponding noise playback source, providing a hardware foundation for wheel-rail noise playback in an airtight test bench.

[0084] According to embodiments of this disclosure, the plurality of noise playback sources includes a plurality of dodecahedral sound sources; the plurality of dodecahedral sound sources are respectively disposed at axle positions corresponding to different bogie regions of the track vehicle under test. In one embodiment, the plurality of noise playback sources includes four dodecahedral sound sources; the four dodecahedral sound sources are respectively disposed at four axle positions corresponding to two bogie regions of the track vehicle under test. The four dodecahedral sound sources correspond one-to-one with the four axle positions, so that the longitudinal placement of the noise playback sources in the vehicle corresponds to the region where wheel-rail noise is generated. Regarding the process of the dodecahedral sound sources forming a simulated tunnel sound field based on the wheel-rail noise playback signal, please refer to the relevant description in the corresponding embodiments of the aforementioned vehicle noise testing method.

[0085] Four dodecahedral sound sources are distributed in the two bogie areas of the track vehicle under test, and are respectively set at the corresponding axle positions. Since wheel-rail noise is mainly generated at the wheel-rail contact position, configuring the noise playback sound sources according to the axle positions can establish a spatial correspondence between the acoustic output position and the actual wheel-rail noise generation position, thereby using the acoustic output at multiple positions to characterize the wheel-rail noise distribution in the bogie area.

[0086] For example, in one specific implementation, for the simulation of tunnel wheel-rail noise at a speed level of 80km / h for rail vehicles, a dodecahedral sound source can be set at each of the four axle positions corresponding to the two bogie areas under the vehicle, for a total of four dodecahedral sound sources. The tunnel wheel-rail noise at the corresponding speed level can be played back using the four dodecahedral sound sources.

[0087] According to the embodiments of this disclosure, by setting four dodecahedral sound sources at the four axle positions corresponding to the two bogie areas, the positions of the noise playback sound sources correspond to the wheel-rail noise generation areas, which can reduce the difference between the sound source arrangement positions and the actual wheel-rail noise spatial positions, and is beneficial to reproduce the wheel-rail noise spatial distribution in the bogie area in the airtight test bench.

[0088] According to embodiments of this disclosure, the multiple sensors include two target control point sensors and multiple monitoring point sensors. The two target control point sensors are located on the bogie area of ​​the track vehicle under test, corresponding to the actual track sampling location. The multiple monitoring point sensors are located in the undercarriage area, sidewall area, and roof area at the middle and both ends of the track vehicle under test. The functions of the target control point sensors and monitoring point sensors can be referred to the relevant descriptions in the corresponding embodiments of the aforementioned vehicle noise testing method. In this embodiment, the two target control point sensors form noise acquisition locations corresponding to the actual track sampling location; the multiple monitoring point sensors are distributed at different longitudinal positions of the vehicle and in different spatial areas of the undercarriage, sidewalls, and roof.

[0089] Two target control point sensors are centrally located within the bogie area at positions corresponding to the actual track sampling locations, used to acquire noise data with a correspondence to the actual track sampling locations; multiple monitoring point sensors are distributed in the middle and both ends of the vehicle body, respectively covering the undercarriage area, side wall area and roof area, thus forming a noise acquisition layout that combines target control points with multiple area monitoring points.

[0090] For example, two target control point sensors can be arranged in the bogie area of ​​the track vehicle under test, corresponding to the measurement points of the actual track spectrum collection location. At the same time, monitoring point sensors can be set in the undercarriage area, side wall area, and roof area at the middle and both ends of the vehicle body, respectively, so that the sensor measurement point distribution can simultaneously cover the corresponding location of the actual track spectrum collection, different longitudinal positions of the vehicle, and different vehicle body areas.

[0091] According to the embodiments of this disclosure, by setting two target control point sensors corresponding to the actual track spectrum locations, and setting multiple monitoring point sensors in the undercarriage, side walls, and roof areas of the vehicle body in the middle and at both ends, a reference acquisition position with a corresponding relationship to the actual track location and a monitoring position covering different spatial areas of the vehicle can be formed simultaneously in the system. This allows for the acquisition of data that reflects the noise playback situation and the noise status of different areas of the vehicle, which is beneficial for characterizing the spatial distribution of noise of the track vehicle under simulated tunnel sound field.

[0092] According to embodiments of this disclosure, a digital audio processor includes a pre-equalizer and a post-equalizer; the pre-equalizer and post-equalizer respectively adjust multiple different processing frequency bands in the wheel-rail noise playback signal; the amplitude adjustment range of each frequency band is ±15dB. The pre-equalizer and post-equalizer can each serve as frequency band adjustment functional units in the digital audio processor, and each corresponds to a set of frequency ranges, enabling the wheel-rail noise playback signal to be amplitude adjusted according to different frequency ranges. The amplitude of each frequency band can be adjusted within a range of decreasing to increasing by 15dB.

[0093] The digital audio processor creates multiple adjustable frequency bands through a pre-equalizer and a post-equalizer. Each frequency band can be set with its own amplitude adjustment parameters, thus enabling amplitude control of different frequency regions of the wheel-rail noise playback signal. For specific processing methods regarding amplitude adjustment of each frequency band, please refer to the relevant descriptions in the corresponding embodiments of the aforementioned vehicle noise testing method.

[0094] For example, in one specific implementation, the pre-equalizer can correspond to 8 1 / 3 octave bands, and the post-equalizer can correspond to 9 1 / 3 octave bands, thus forming 17 core frequency bands; each band can be amplitude adjusted within ±15dB to control the sound pressure level corresponding to different frequency regions.

[0095] According to embodiments of this disclosure, by setting pre-equalization and post-equalization corresponding to multiple frequency bands in a digital audio processor and limiting the amplitude adjustment range of each frequency band, independent amplitude adjustment capability of multiple frequency bands can be provided, enabling different frequency regions of the wheel-rail noise playback signal to be adjusted separately, reducing the difficulty in correcting local spectral differences by only adjusting the overall sound pressure level.

[0096] According to an embodiment of this disclosure, the noise control system determines the gain adjustment amount corresponding to each frequency band based on the difference between the wheel-rail noise spectrum and the playback spectrum; the digital audio processor performs iterative gain adjustment on each frequency band according to the gain adjustment amount corresponding to each frequency band. The specific meanings of the gain adjustment amount and the iterative gain adjustment can be found in the relevant descriptions in the corresponding embodiments of the aforementioned vehicle noise testing method. In this embodiment, a correspondence is established between the spectral difference of each frequency band and the gain adjustment amount, and the digital audio processor, as the execution part of the gain adjustment, adjusts the corresponding frequency bands respectively.

[0097] The spectral difference between the wheel-rail noise spectrum and the corresponding frequency bands of the current playback spectrum can be determined, and the corresponding gain adjustment amount can be determined accordingly. After the digital audio processor completes one adjustment, it can continue to perform the next gain adjustment based on the updated playback spectrum, thereby gradually reducing the spectral differences between each frequency band. For the specific iterative processing procedure, please refer to the relevant descriptions in the corresponding embodiments of the aforementioned vehicle noise testing method.

[0098] For example, based on the aforementioned adjustable frequency bands, the wheel-rail noise spectrum and playback spectrum of each band can be compared separately. When the playback spectrum of a certain frequency band is lower than the corresponding wheel-rail noise spectrum, the gain adjustment amount used to increase the output of that frequency band can be determined; when the playback spectrum is higher than the corresponding wheel-rail noise spectrum, the gain adjustment amount used to decrease the output of that frequency band can be determined. The digital audio processor performs multiple adjustments according to the gain adjustment amount corresponding to each frequency band until the spectral error reaches the set target range.

[0099] According to the embodiments of this disclosure, by establishing the correspondence between the spectral difference of each frequency band and the gain adjustment amount, and by performing iterative gain adjustment on each frequency band by a digital audio processor, playback deviation can be continuously corrected for different frequency regions, so that the playback spectrum gradually approaches the actual rail-wheel noise spectrum of the line, thereby improving the reproduction degree of the actual rail-wheel noise spectrum of the line in the airtight test bench.

[0100] According to embodiments of this disclosure, multiple sensors are distributed across multiple test sections arranged longitudinally along the track vehicle under test. Each test section is equipped with sensors located in the undercarriage area, sidewall area, and roof area. The test sections can be transverse test locations selected along the longitudinal direction of the track vehicle under test, used to characterize the noise state at the corresponding longitudinal position. The multiple test sections distributed along the longitudinal direction of the track vehicle under test enable sensors at different test sections to collect noise data corresponding to different longitudinal positions of the vehicle. Within the same test section, by setting sensors in the undercarriage area, sidewall area, and roof area respectively, noise data corresponding to different areas of the vehicle body at the same longitudinal position can be obtained. Thus, multiple sensors form a noise acquisition layout that simultaneously covers the longitudinal position of the vehicle and different areas of the vehicle body.

[0101] For example, in one specific implementation, three test sections can be selected along the longitudinal direction of the track vehicle under test: the end of the vehicle, the quarter-body position, and the middle of the vehicle body. Sensors are installed at the center of the vehicle floor, the height of the side wall windows, and the center of the roof at each test section. During noise testing, each sensor collects noise data at its corresponding test location, thereby obtaining noise information for different test sections and different areas of the same test section.

[0102] According to the embodiments of this disclosure, by setting multiple test sections along the longitudinal direction of the track vehicle under test, and setting sensors in the undercarriage area, side wall area and roof area of ​​each test section, noise data can be collected from two spatial dimensions: the longitudinal position of the vehicle and the vehicle body area. The collected results can reflect the changes in noise along the longitudinal direction of the vehicle and the distribution differences between the undercarriage, side wall and roof, thereby providing multi-location noise data for obtaining the noise distribution of the track vehicle under test in a simulated tunnel sound field.

[0103] Figure 3The diagram illustrates the hardware connections and noise playback test link of a noise control system according to an embodiment of the present disclosure.

[0104] like Figure 3 As shown, the noise control system includes a control computer, a digital audio processor, a signal distributor, and a power amplifier connected in sequence. The power amplifier is connected to multiple dodecahedral sound sources. These dodecahedral sound sources are positioned corresponding to the vehicle under test. A sensor array is used to collect noise data from corresponding locations on the vehicle under test and transmits the collected results to the control computer. This forms a noise simulation playback test chain consisting of noise signal loading, digital signal processing, signal distribution, power amplification, noise playback, noise acquisition, and spectrum analysis.

[0105] The control computer can run a noise control program to load pre-collected track wheel-rail noise data and generate a wheel-rail noise playback signal to be played back based on this data. It can also receive noise data collected by a sensor array, obtain the current playback spectrum based on the collected noise data, and compare the current playback spectrum with the pre-collected actual tunnel track wheel-rail noise spectrum to obtain the spectral differences corresponding to different frequency bands. Based on the spectral differences, corresponding signal adjustment parameters can be determined and configured to the digital audio processor, thereby adjusting the wheel-rail noise playback signal.

[0106] The digital audio processor receives the wheel-rail noise playback signal output from the control computer and adjusts its amplitude according to multiple frequency bands. In one specific implementation, the digital audio processor's pre-equalization and post-equalization can create 17 independently adjustable one-third octave bands, with the pre-equalization covering 8 bands and the post-equalization covering 9 bands. The amplitude adjustment range for each band can be ±15dB. Therefore, for local spectral differences between the current playback spectrum and the actual tunnel track wheel-rail noise spectrum, independent gain adjustment can be performed on the corresponding frequency bands without requiring all bands to change synchronously with the same gain.

[0107] The signal distributor receives the wheel-rail noise playback signal, which has been regulated by the digital audio processor, and distributes it to the corresponding signal transmission paths. In one specific implementation, the digital audio processor can provide eight signal outputs. The distributed wheel-rail noise playback signal is input to a power amplifier, which amplifies the signal to achieve the power level required to drive the dodecahedral sound source for noise playback.

[0108] Multiple dodecahedral sound sources receive the amplified wheel-rail noise playback signal and convert it into acoustic output to create a sound field around the vehicle under test, simulating the actual wheel-rail noise environment of a tunnel. In one specific implementation, a dodecahedral sound source can be placed at each of the four axle positions corresponding to the two bogie regions under the vehicle under test, for a total of four dodecahedral sound sources. Since the axle positions correspond to the areas where wheel-rail contact generates noise during vehicle operation, by playing back noise at different axle positions, a spatial correspondence can be established between the acoustic output position and the actual wheel-rail noise generation position.

[0109] The sensor array may include target control point sensors and monitoring point sensors. Target control point sensors may be set in the bogie area at positions corresponding to the actual wheel-rail noise locations on the track, and are used to collect playback noise data as a basis for spectrum adjustment; monitoring point sensors may be set in the undercarriage area, side wall area, and roof area at different longitudinal positions of the vehicle, and are used to collect noise data corresponding to different spatial locations under simulated tunnel sound fields.

[0110] During noise playback, the control computer loads the actual wheel-rail noise data collected from the line. After frequency band adjustment by the digital audio processor, the signal is distributed by the signal distributor and driven by the power amplifier to produce acoustic output from multiple dodecahedral sound sources. The sensor array simultaneously collects noise data under the current sound field and returns the results to the control computer for spectrum analysis. The control computer determines the gain adjustment amount corresponding to each frequency band based on the difference between the actual tunnel line wheel-rail noise spectrum and the current playback spectrum. The digital audio processor adjusts the gain according to the corresponding gain adjustment amount for each frequency band. After one adjustment is completed, noise playback, data acquisition, and spectrum comparison are performed again, and the corresponding frequency bands are adjusted again based on the updated spectrum differences.

[0111] Figure 4 The diagram schematically illustrates the arrangement of noise measurement points inside and outside the vehicle and noise playback sources according to an embodiment of the present disclosure.

[0112] like Figure 4 As shown, solid circles represent external noise measurement points, textured circles represent noise playback sources, and crossed circles represent internal noise measurement points. These different types of graphic markers can characterize the spatial relationship between external noise measurement points, internal noise measurement points, and noise playback sources relative to the track vehicle being measured. It should be noted that... Figure 4 The content shown should be viewed after rotating 90 degrees counterclockwise. The right and lower sections below are all indicated by... Figure 4 The image after counterclockwise rotation is used as the reference.

[0113] Along the longitudinal direction of the track vehicle under test, three test sections can be selected: one at the end of the vehicle, one-quarter of the vehicle body, and one in the middle of the vehicle body. These three test sections correspond to different positions along the longitudinal direction of the vehicle and are used to acquire noise data at these different longitudinal locations. For each test section, external noise measurement points can be set in the undercarriage area, the sidewall area, and the roof area, respectively. Specifically, the external noise measurement point in the undercarriage area can be located at the center of the undercarriage, the external noise measurement point in the sidewall area can be located at the height of the sidewall window, and the external noise measurement point in the roof area can be located at the center of the roof. The external noise measurement points of each test section cover the undercarriage, sidewall, and roof areas along the vehicle's height, and the external noise measurement points of different test sections are spaced apart along the longitudinal direction of the vehicle. This arrangement of measurement points corresponds to the description of multiple test sections and the undercarriage, sidewall, and roof areas in the aforementioned embodiments.

[0114] like Figure 4 As shown in the vehicle cross-section on the right, the external noise measurement points corresponding to the same test section can be distributed along different areas of the vehicle cross-section. External noise measurement points located in the roof area are used to collect noise data near the roof; those located in the sidewall area are used to collect noise data near the sidewalls; and those located in the undercarriage area are used to collect noise data near the undercarriage. By comparing the noise data from different areas within the same test section, the variation of noise from the undercarriage area to the sidewall and roof areas can be obtained; by comparing the noise data from different test sections, the variation of noise along the vehicle's longitudinal direction can be obtained.

[0115] External noise measurement points can be further divided into target control points and monitoring points based on the testing purpose. Target control points can be placed in the bogie area at locations corresponding to the actual track noise sampling positions, establishing a spatial correspondence between the noise sampling locations of the target control points and the actual track wheel-rail noise sampling locations. The playback noise data collected by the target control points can be used to obtain the playback spectrum within the airtightness test bench and serve as the basis for adjusting the wheel-rail noise playback signal spectrum. Monitoring points can be distributed at different longitudinal positions and different areas of the vehicle body to acquire noise data at corresponding locations under simulated tunnel sound fields. For example, two target control point sensors can be used, with multiple monitoring point sensors covering the undercarriage area, side wall area, and roof area at the middle and both ends of the vehicle body.

[0116] Inside the track vehicle being tested, multiple in-vehicle noise measurement points can be set along the longitudinal direction of the vehicle. For example... Figure 4 As shown in the lower part, three in-vehicle noise measurement points can be set up at intervals along the longitudinal direction of the vehicle, allowing each of the three measurement points to collect noise data at different longitudinal positions inside the vehicle. By comparing the noise data corresponding to different in-vehicle noise measurement points, the distribution of in-vehicle noise along the longitudinal direction of the vehicle under a simulated tunnel sound field can be obtained.

[0117] Multiple noise playback sources are installed in the undercarriage area of ​​the track vehicle under test. Specifically, a dodecahedral sound source can be installed at each of the four axle positions corresponding to the two bogie areas, for a total of four dodecahedral sound sources. The four dodecahedral sound sources are divided into two groups along the longitudinal direction of the vehicle, with each group corresponding to one bogie area, and the position of each dodecahedral sound source is matched with the corresponding axle position. Since wheel-rail noise is mainly generated in the wheel-rail contact area, by playing back the wheel-rail noise at the positions corresponding to the four axles, a spatial correspondence can be established between the noise playback positions and the areas where wheel-rail noise is generated during the actual operation of the vehicle.

[0118] During noise testing, four dodecahedral sound sources generate acoustic outputs based on the adjusted wheel-rail noise playback signal, forming a simulated tunnel sound field around the tested rail vehicle. Target control points collect playback noise data corresponding to the actual track spectrum locations. External monitoring points collect noise data at different longitudinal positions of the vehicle, as well as in the undercarriage, sidewalls, and roof areas. Internal noise measurement points collect noise data at different longitudinal positions within the vehicle. This allows for a noise testing layout covering the wheel-rail noise playback location, playback spectrum control location, different external areas, and different internal locations, to obtain the internal and external noise distribution of the tested rail vehicle under a simulated tunnel sound field.

[0119] According to an embodiment of this disclosure, a vehicle is also provided. The vehicle includes the vehicle noise testing system described in any of the foregoing embodiments. The vehicle noise testing system may include an airtight test bench, a noise control system, multiple noise playback sources, and multiple microphones. The noise control system is used to adjust the wheel-rail noise playback signal based on the difference between the actual tunnel track wheel-rail noise spectrum and the playback spectrum within the airtight test bench; the multiple noise playback sources are used to form a simulated tunnel sound field based on the adjusted wheel-rail noise playback signal; and the multiple microphones are used to collect noise data at the corresponding location of the vehicle under the simulated tunnel sound field to obtain the noise distribution corresponding to the vehicle.

[0120] In one embodiment, the vehicle can be placed inside an airtight test bench, and its noise characteristics under simulated tunnel sound field conditions can be tested using a vehicle noise testing system. Through the cooperation between the vehicle and the vehicle noise testing system, noise distribution data corresponding to the vehicle can be obtained in a test environment that matches the simulated tunnel sound field conditions.

[0121] Figure 5 A block diagram of a control computer in a noise control system according to an embodiment of the present disclosure is shown schematically. The control computer in the noise control system can be implemented based on electronic device 500, which will be used as an example in the following description. It should be noted that... Figure 5The illustrated electronic device 500 is merely an example and should not be construed as limiting the functionality and scope of the embodiments disclosed herein.

[0122] like Figure 5 As shown, an electronic device 500 according to an embodiment of this disclosure includes a processor 501, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 502 or a program loaded from a storage portion 508 into a random access memory (RAM) 503. The processor 501 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 501 may also include onboard memory for caching purposes. The processor 501 may include a single processing unit or multiple processing units for performing different actions of noise control processing implemented by a control computer according to the foregoing embodiments.

[0123] RAM 503 stores various programs and data required for the operation of electronic device 500. Processor 2201, ROM 502, and RAM 503 are interconnected via bus 504. Processor 2201 executes various operations of the noise control processing implemented by the control computer according to the foregoing embodiments by executing programs in ROM 502 and / or RAM 503. It should be noted that the programs may also be stored in one or more memories other than ROM 502 and RAM 503. Processor 501 may also execute various operations of the noise control processing implemented by the control computer in the foregoing embodiments by executing programs stored in said one or more memories.

[0124] According to embodiments of this disclosure, the electronic device 500 may further include an input / output (I / O) interface 505, which is also connected to a bus 504. The electronic device 500 may also include one or more of the following components connected to the input / output (I / O) interface 505: an input section 506 including a keyboard, mouse, etc.; an output section 507 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 508 including a hard disk, etc.; and a communication section 509 including a network interface card such as a LAN card, modem, etc. The communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to the input / output (I / O) interface 505 as needed. A removable medium 511, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 510 as needed so that computer programs read from it can be installed into the storage section 508 as needed.

[0125] According to embodiments of this disclosure, the noise control processing implemented by the control computer in the foregoing embodiments can be implemented as a computer software program. For example, embodiments of this disclosure include a computer program product comprising a computer program carried on a computer-readable storage medium, the computer program containing program code for performing the noise control processing implemented by the control computer in the foregoing embodiments. In such embodiments, the computer program can be downloaded and installed from a network via communication section 509, and / or installed from removable medium 511. When the computer program is executed by processor 501, the functions defined above in the functions implemented by the control computer in the noise control system are performed. According to embodiments of this disclosure, the data processing and control functions related to noise control described above can be implemented by computer program modules.

[0126] This disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs that, when executed, cause the electronic device to perform the noise control processing implemented by the control computer in the foregoing embodiments.

[0127] According to embodiments of this disclosure, the computer-readable storage medium can be a non-volatile computer-readable storage medium. Examples include, but are not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this disclosure, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0128] For example, according to embodiments of this disclosure, a computer-readable storage medium may include ROM 502 and / or RAM 503 and / or one or more memories other than ROM 502 and RAM 503 as described above.

[0129] Embodiments of this disclosure also include a computer program product comprising a computer program containing program code for performing the noise control processing implemented by the control computer in the foregoing embodiments. When the computer program product is run on an electronic device, the program code is used to cause the electronic device to perform the noise control processing implemented by the control computer in the foregoing embodiments.

[0130] When the computer program is executed by the processor 501, it performs the functions described above, which are implemented by the control computer in the noise control system. According to embodiments of this disclosure, the noise control functions described above can be implemented by a computer program module.

[0131] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may also be transmitted and distributed in the form of signals over a network medium, and may be downloaded and installed via the communication section 509, and / or installed from a removable medium 511. The program code contained in the computer program can be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.

[0132] According to embodiments of this disclosure, program code for executing the computer programs provided in embodiments of this disclosure can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C", or similar programming languages. The program code can be executed entirely on a local electronic device, partially on a local electronic device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the local electronic device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0133] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0134] Those skilled in the art will understand that the features described in the various embodiments of this disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0135] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A method for testing vehicle noise, characterized in that, include: Based on the differences in spatial and acoustic parameters between the airtight test bench and the tunnel to be simulated, the tunnel acoustic field simulation conditions of the airtight test bench are determined. A sound field simulation test environment matching the tunnel sound field simulation conditions is constructed; the sound field simulation test environment includes a noise control system, multiple noise playback sources, and multiple sensors; Based on the difference between the pre-collected actual tunnel track wheel-rail noise spectrum and the playback spectrum in the airtight test bench, the wheel-rail noise playback signal is adjusted by the noise control system. A simulated tunnel sound field is formed by multiple noise playback sources based on the adjusted wheel-rail noise playback signal; The noise data of the track vehicle under test is collected by multiple sensors under the simulated tunnel sound field to obtain the noise distribution of the track vehicle under test.

2. The method according to claim 1, characterized in that, The spatial parameter differences include the cross-sectional dimension differences between the airtight test bench and the tunnel to be simulated; the acoustic parameter differences include the reverberation time differences between the airtight test bench and the tunnel to be simulated. The method for determining the tunnel acoustic field simulation conditions of the airtight test rig based on the differences in spatial and acoustic parameters between the airtight test rig and the tunnel to be simulated includes: The cross-sectional dimensions of the airtightness test bench are determined based on the difference in cross-sectional dimensions. The reverberation time difference between the reverberation time of the airtight test bench in the open end door state and the reverberation time of the tunnel to be simulated is determined respectively. The end gate state with a small difference between its reverberation time in the open and closed states and the reverberation time of the tunnel to be simulated is determined as the tunnel sound field simulation condition.

3. The method according to claim 1, characterized in that, The plurality of noise playback sources include a plurality of dodecahedral sound sources; The construction of a sound field simulation test environment that matches the tunnel sound field simulation conditions includes: At least one dodecahedral sound source is arranged at the axle position corresponding to each bogie area of ​​the track vehicle under test.

4. The method according to claim 1, characterized in that, The multiple sensors include multiple target control point sensors and multiple monitoring point sensors; The construction of a sound field simulation test environment that matches the tunnel sound field simulation conditions includes: Multiple target control point sensors are arranged in the bogie area of ​​the track vehicle under test at locations corresponding to the actual track spectrum locations. Multiple monitoring point sensors are arranged in the undercarriage area, side wall area, and roof area of ​​the track vehicle under test in the middle and both ends of the vehicle body.

5. The method according to claim 1, characterized in that, The noise control system includes a digital audio processor; The adjustment of the wheel-rail noise playback signal through the noise control system includes: The digital audio processor adjusts the amplitude of multiple frequency bands corresponding to the wheel-rail noise playback signal.

6. The method according to claim 5, characterized in that, The adjustment of the wheel-rail noise playback signal through the noise control system includes: The gain adjustment amount corresponding to each frequency band is determined based on the difference between the wheel-rail noise spectrum and the playback spectrum. According to the gain adjustment amount corresponding to each frequency band, the gain of each frequency band is iteratively adjusted.

7. The method according to claim 1, characterized in that, The process of collecting noise data of the track vehicle under test in the simulated tunnel sound field using multiple sensors includes: Multiple test sections are selected along the longitudinal direction of the track vehicle under test; Sensors are arranged in the vehicle underside area, side wall area, and roof area corresponding to each of the test sections; Multiple sets of noise sound pressure level data were collected for each of the test sections; The average value of multiple sets of noise sound pressure level data for the same test section is calculated as the noise data corresponding to the test section.

8. A vehicle noise testing system, characterized in that, include: Air tightness test bench; A noise control system is used to adjust the wheel-rail noise playback signal based on the difference between the pre-acquired actual tunnel line wheel-rail noise spectrum and the playback spectrum in the airtight test bench. Multiple noise playback sources are connected to the noise control system to form a simulated tunnel sound field in the airtight test bench based on the adjusted wheel-rail noise playback signal. Multiple sensors are used to collect playback noise data within the airtight test bench and noise data of the track vehicle under test under the simulated tunnel sound field; wherein, the playback spectrum is the spectrum corresponding to the playback noise data, and the noise data of the track vehicle under test is used to obtain the noise distribution of the track vehicle under test. The airtight test bench, the noise control system, the multiple noise playback sources, and the multiple sensors together constitute a sound field simulation test environment that matches the tunnel sound field simulation conditions. The tunnel sound field simulation conditions are determined based on the differences in spatial parameters and acoustic parameters between the airtight test bench and the tunnel to be simulated.

9. The system according to claim 8, characterized in that, The noise control system includes a control computer, a digital audio processor, a signal distributor, and a power amplifier connected in sequence. The power amplifier is connected to multiple noise playback sources.

10. The system according to claim 8, characterized in that, The plurality of noise playback sources include a plurality of dodecahedral sound sources; The multiple dodecahedral sound sources are respectively set at the axle positions corresponding to different bogie regions of the track vehicle under test.

11. The system according to claim 8, characterized in that, The plurality of sensors include two target control point sensors and multiple monitoring point sensors; The two target control point sensors are set in the bogie area of ​​the track vehicle under test at the location corresponding to the actual track spectrum of the line. Multiple monitoring point sensors are installed in the undercarriage area, side wall area, and roof area of ​​the track vehicle under test in the middle and both ends of the vehicle body.

12. The system according to claim 9, characterized in that, The digital audio processor has a pre-equalizer and a post-equalizer; The pre-equalizer and the post-equalizer respectively adjust multiple different processing frequency bands in the wheel-rail noise playback signal.

13. The system according to claim 12, characterized in that, The noise control system is used to determine the gain adjustment amount corresponding to each frequency band based on the difference between the wheel-rail noise spectrum and the playback spectrum; The digital audio processor is used to iteratively adjust the gain of each frequency band according to the gain adjustment amount corresponding to each frequency band.

14. The system according to claim 8, characterized in that, Multiple sensors are distributed along multiple test sections arranged longitudinally along the track vehicle under test; Each of the test sections is equipped with sensors located in the undercarriage area, side wall area, and roof area.

15. A vehicle, characterized in that, include: The vehicle noise testing system according to any one of claims 8-14.

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