Vehicle surface pressure pulsation measuring system

Abstract

The invention relates to a vehicle surface pressure pulsation measuring system which comprises a flow-sound pressure pulsation measuring device, a data acquisition module and an upper computer which are connected in sequence. Wherein the flow-sound pressure pulsation measurement device has an aerodynamic shape and variable curvature, and comprises a substrate, a turbulent flow pressure pulsation measurement area and a sound pressure pulsation measurement area, and the turbulent flow pressure pulsation measurement area and the sound pressure pulsation measurement area both comprise a plurality of micro-electro-mechanical microphones designed and arranged according to the optimal spacing range; the micro-electro-mechanical microphones in the turbulent flow pressure pulsation measurement area are arranged in a triangular shape, and the direction pointed by the vertex angle of the triangle faces the wind; the micro-electro-mechanical microphones in the sound pressure pulsation measurement area are arranged in an array, and acoustic covering films are attached to the measurement surfaces of all the micro-electro-mechanical microphones; the data acquisition module acquires data of all micro electro mechanical microphones in the flow-sound pressure pulsation measuring device in real time and transmits the data to the upper computer for storage, analysis and recording. Compared with the prior art, the method has high accuracy and integration level.

Description

Technical Field

[0001] The invention belongs to the field of automobile wind noise testing, and in particular relates to a vehicle surface pressure pulsation measurement system. Background Art

[0002] Cars are one of the most important ground transportation tools today. With the continuous advancement of technology, consumers no longer regard them as a simple means of transportation, and have also put forward higher requirements for other performance of vehicles. Comfort has become one of the important consumer evaluation indicators, and the noise inside the car is a core indicator of comfort, which directly affects the auditory perception and emotional experience of the people in the car. During driving, the airflow flows through the surface of the car body, and the airflow noise and the vortex generated by separation and the turbulent pressure pulsation generated in the boundary layer are directly or indirectly transmitted to the car through excitation to cause the structural vibration of the vehicle surface (such as doors, windows, sunroofs, etc.), thereby increasing the noise inside the car. In order to reduce the noise level inside the car, targeted measurements need to be carried out during the development of the vehicle's wind noise performance to evaluate the influence of the vehicle's local styling or spare parts on the noise inside the car.

[0003] From the above content, it can be seen that the external flow field excites the surface of the vehicle body and transmits it to the interior of the vehicle to generate aerodynamic noise inside the vehicle. There are two different pressure pulsation excitation sources, namely, hydrodynamic and acoustic. The two are very different in energy level, propagation mode, and form of sound insulation through the vehicle body, and the noise reduction measures taken are also very different. At present, surface microphone sensors are generally used to perform limited measurements of single-point or multi-point vehicle body related surfaces. However, the existing test technology is limited by the large size of the sensor and the transducer principle, and it is difficult to fully meet the needs of acoustic prediction in terms of time sampling frequency, spatial sampling density, sampling accuracy, etc.; in addition, the existing measurement device is large in size, which will interfere with the flow on the surface of the object being measured, resulting in measurement errors. Even if it can meet the accuracy requirements to a certain extent, the cost is relatively high due to the large number of measurement points. In addition, the existing test technology cannot completely separate the two different pressure pulsation excitations of flow and acoustic, so it is difficult to accurately evaluate the impact of aerodynamic noise generated by the external flow field on the acoustic quality inside the vehicle. In summary, it is necessary to design a vehicle surface pressure pulsation measurement solution with higher accuracy and integration. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a vehicle surface pressure pulsation measurement system with higher accuracy and integration and lower cost.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] The present invention provides a vehicle surface pressure pulsation measurement system, which includes a fluid-acoustic pressure pulsation measurement device, a data acquisition module, and a host computer that are connected in sequence;

[0007] Among them, the fluid-acoustic pressure pulsation measurement device has an aerodynamic shape and variable curvature. It includes a substrate and a turbulent pressure pulsation measurement area and a sound pressure pulsation measurement area arranged on the substrate. The upper surfaces of the turbulent pressure pulsation measurement area and the sound pressure pulsation measurement area are located on the same horizontal plane. Both of them include a plurality of microelectromechanical microphones designed and arranged according to the optimal spacing range, and the optimal spacing range is calculated according to the wave number-frequency spectrum measurement requirements; the microelectromechanical microphones in the turbulent pressure pulsation measurement area are arranged in a triangular pattern, and the direction pointed by the apex of the triangle faces the wind; the microelectromechanical microphones in the sound pressure pulsation measurement area are arranged in an array, and all the microelectromechanical microphones are attached with acoustic coating films on the measurement surface of the substrate;

[0008] The data acquisition module is used to obtain the data of all the microelectromechanical microphones in the fluid-acoustic pressure pulsation measurement device in real time in the form of a cable and transmit it to the host computer;

[0009] The host computer is used to store, analyze, and record the obtained data, and output it as the vehicle surface pressure pulsation measurement result.

[0010] Furthermore, a streamlined first oncoming flow guiding structure is provided at the windward end of the substrate, so that the fluid-acoustic pressure pulsation measurement device has an aerodynamic shape.

[0011] Furthermore, the material of the substrate is a flexible material, so that the fluid-acoustic pressure pulsation measurement device has variable curvature.

[0012] Furthermore, the specific process of designing and arranging the microelectromechanical microphones according to the optimal spacing range is as follows:

[0013] In the turbulent pressure pulsation measurement area, the spacing d1 of the microelectromechanical microphones satisfies the following formula:

[0014] d1 = U / (m·n·f)

[0015] Wherein, U represents the oncoming flow velocity, m represents the number of sampling points in one wavelength, n represents the sampling multiple, and f represents the turbulent pressure pulsation frequency;

[0016] In the sound pressure pulsation measurement area, the spacing d2 of the microelectromechanical microphones satisfies the following formula:

[0017] d2 = c / (m·n·f)

[0018] Wherein, c represents the sound propagation velocity.

[0019] Further, when the MEMS microphones in the acoustic pressure pulsation measurement area are arranged in a two-dimensional array, the spacing between each MEMS microphone includes a component d in the x direction x and a component d in the y direction y :

[0020] d x = c / (m·n·f x )

[0021] d y = c / (m·n·f y )

[0022] where f x and f y are the frequency components of the sound wave in the x and y directions, respectively.

[0023] Further, in the acoustic pressure pulsation measurement area, the measurement holes of all MEMS microphones are in one measurement plane.

[0024] Further, a first cable interface is provided on the substrate. The data acquisition module includes a power supply interface, a data acquisition sub-module, a first communication sub-module, and a second cable interface that are respectively connected to the power supply interface. The number of channels of the second cable interface is the same as that of the first cable interface. The data of the MEMS microphones is sequentially transmitted to the data acquisition sub-module through the first cable interface and the second cable interface, and then transmitted to the host computer through the first communication sub-module.

[0025] Further, a streamlined second oncoming flow diversion structure is provided at the front end of the first cable interface.

[0026] Further, the host computer includes a power supply sub-module, a second communication sub-module, a storage unit, a measurement unit, and a display unit that are respectively connected to the power supply sub-module. The power supply sub-module is connected to the power supply interface. The data of the MEMS microphones is sequentially transmitted to the storage unit through the first communication sub-module and the second communication sub-module. When setting the measurement unit, according to the setting of the flow-acoustic pressure pulsation measurement device, the corresponding array type is selected, the working condition is named according to actual needs, and a data recording instruction is sent. The data sensed by the flow-acoustic pressure pulsation measurement device is collected through the data acquisition module and stored in the storage unit through the second communication sub-module, and is simultaneously synchronously displayed on the display unit. After the measurement is completed, the required working condition data is exported and stored in a specified path according to requirements through a data output instruction.

[0027] Further, the interface between the first communication sub-module and the second communication sub-module is TCP / IP or USB.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention provides a vehicle surface pressure pulsation measurement system, which includes a flow-acoustic pressure pulsation measurement device, a data acquisition module, and a host computer that are connected in sequence. The flow-acoustic pressure pulsation measurement device includes a turbulent pressure pulsation measurement area and a sound pressure pulsation measurement area, which can realize the separation of two different pressure pulsation excitations of flow and sound. The upper surfaces of the turbulent pressure pulsation measurement area and the sound pressure pulsation measurement area are located on the same horizontal plane, which can avoid aerodynamic separation and noise caused by height differences. Both the turbulent pressure pulsation measurement area and the sound pressure pulsation measurement area include a plurality of microelectromechanical microphones designed and arranged according to the optimal spacing range. The optimal spacing range is calculated according to the requirements of wave number-frequency spectrum measurement. Arranging the microelectromechanical microphones accordingly can accurately collect spatial sound pressure information; the microelectromechanical microphones in the turbulent pressure pulsation measurement area are arranged in a triangular pattern, and the direction pointed by the apex angle of the triangle faces the wind. During measurement, the wave number vector can be obtained through wave number decomposition to determine the magnitude and direction of the turbulent velocity (convection velocity); the microelectromechanical microphones in the sound pressure pulsation measurement area are arranged in an array, and all the microelectromechanical microphones are attached with acoustic films on the measurement surface of the substrate. The acoustic films can suppress the self-noise caused by the airflow flowing through the sound inlet holes of the microelectromechanical microphones to improve the measurement accuracy of the sound pressure pulsation; the data acquisition module obtains the data of all the microelectromechanical microphones in real time through a cable connection and transmits it to the host computer. The host computer stores, analyzes, and records the obtained data, and finally outputs the vehicle surface pressure pulsation measurement result. The above system distinguishes and designs the turbulent pressure pulsation measurement area and the sound pressure pulsation measurement area, which can realize the accurate positioning of the airflow velocity and direction; at the same time, it has a compact structure, reasonable arrangement spacing of the microelectromechanical microphones, can measure high-frequency noise, effectively improve the noise measurement range, and has a high integration degree, can realize integrated application and output, and improve the test efficiency.

[0030] 2. The present invention sets a streamlined first oncoming flow guiding structure at the windward end of the substrate, so that the flow-acoustic pressure pulsation measurement device has an aerodynamic shape, which can avoid the separation of the oncoming flow at the front end, resulting in additional eddies and disturbances, and can improve the reliability of the test data; at the same time, the material of the substrate is a flexible material, so that the curvature of the flow-acoustic pressure pulsation measurement device can be changed, which can well adhere to the surface curvature of the measured object area, reduce the measurement error, and ensure the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic structural diagram of the system of the present invention;

[0032] Figure 2 is a top view of the flow-acoustic pressure pulsation measurement device;

[0033] Figure 3 is a cross-sectional schematic diagram of the flow-acoustic pressure pulsation measurement device;

[0034] Figure 4 Schematic diagram of the placement position of the flow-acoustic pressure pulsation measurement device;

[0035] Figure 5 Schematic diagram of the interface of the upper computer display unit;

[0036] Description of the reference numerals:

[0037] 1. First incoming flow guiding structure; 2. Turbulent pressure pulsation measurement area; 3. Sound pressure pulsation measurement area; 4. Substrate; 5. Microelectromechanical microphone; 6. Second incoming flow guiding structure; 7. First cable interface; 8. Height difference; 9. Acoustic coating; 10. Flow-acoustic pressure pulsation measurement device; 11. Data acquisition module; 12. Upper computer; 13. Second cable interface; 14. Data acquisition sub-module; 15. Power supply interface; 16. First communication sub-module; 17. Second communication sub-module; 18. Power supply sub-module; 19. Storage unit; 20. Measurement unit; 21. Display unit. Detailed implementation manners

[0038] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0039] Embodiment:

[0040] This embodiment provides a vehicle surface pressure pulsation measurement system, as Figure 1 shown, including a flow-acoustic pressure pulsation measurement device 10, a data acquisition module 11 and an upper computer 12 that are connected in sequence.

[0041] The rear surface of the flow-acoustic pressure pulsation measurement device 10 is provided with an adhesive layer, as Figure 4 shown. When using it for measurement, the flow-acoustic pressure pulsation measurement device 10 is attached to the surface of the relevant measurement area of the vehicle. As Figure 2 shown, the flow-acoustic pressure pulsation measurement device 10 includes a substrate 4 and a turbulent pressure pulsation measurement area 2 and a sound pressure pulsation measurement area 3 arranged on the substrate 4. Both of them include a plurality of microelectromechanical microphones 5 designed and arranged according to the optimal spacing range. The optimal spacing range refers to the optimal microphone arrangement spacing that can accurately collect spatial sound pressure information. In order to accurately collect spatial sound pressure information, the arrangement spacing of the microphones needs to meet the requirements of wavenumber-frequency spectrum measurement.

[0042] The MEMS microphones 5 in the turbulent pressure pulsation measurement area 2 are arranged in a triangular pattern, and the direction pointed by the apex of the triangle faces the wind. In this embodiment, 3 MEMS microphones are provided, and the wavenumber vector is obtained through wavenumber decomposition to determine the magnitude and direction of the turbulent velocity (convection velocity). The spacing d1 between the 3 MEMS microphones follows the following optimal range design principle:

[0043] d1 = U / (m·n·f)

[0044] where U represents the oncoming flow velocity, m represents the number of sampling points per wavelength, n represents the sampling multiple (the minimum value is 2, and generally 2.56 is taken in engineering), and f represents the turbulent pressure pulsation frequency.

[0045] The MEMS microphones 5 in the sound pressure pulsation measurement area 3 are arranged in an array (such as a rectangle), and the measurement holes of all the MEMS microphones 5 are in a measurement plane. The spacing d2 between the MEMS microphones 5 satisfies the following formula:

[0046] d2 = c / (m·n·f)

[0047] where c represents the sound propagation velocity.

[0048] When the MEMS microphones 5 in the sound pressure pulsation measurement area 3 are arranged in a two-dimensional array, the spacing between the MEMS microphones 5 includes the component d x in the x direction and the component d y in the y direction:

[0049] d x = c / (n·n·f x )

[0050] d y = c / (m·n·f y )

[0051] where f x and f y are the frequency components of the sound wave in the x and y directions respectively.

[0052] As Figure 3 shown, an acoustic coating film 9 is attached to the measurement surface of the substrate 4 for all the MEMS microphones 5 in the sound pressure pulsation measurement area 3. The acoustic coating film 9 is a layer of dense porous breathable material, and its purpose is to suppress the self-noise caused by the airflow flowing through the sound inlet holes of the MEMS microphones 5 to improve the measurement accuracy of the sound pressure pulsation. In a preferred embodiment, after the MEMS microphones 5 in the sound pressure pulsation measurement area 3 are attached with the acoustic coating film 9, they are located on the same horizontal plane as the upper surface of the turbulent pressure pulsation measurement area 2 to avoid the aerodynamic separation and noise caused by the height difference 8.

[0053] As Figure 3As shown, a streamlined first oncoming flow guiding structure 1 is provided at the windward end of the substrate 4, so that the flow-acoustic pressure pulsation measuring device 11 has an aerodynamic shape, which can avoid the separation of the oncoming flow at the front end, resulting in additional eddy currents and disturbances, so as to improve the reliability of test data. In addition, the substrate 4 is made of a flexible material (such as FPC), so that the curvature of the flow-acoustic pressure pulsation measuring device 11 can be changed, and it can be firmly attached according to the surface curvature of the measured object area.

[0054] The data acquisition module 11 obtains the data of all the microelectromechanical microphones 5 in the flow-acoustic pressure pulsation measuring device 10 in real time in the form of a wiring harness, and transmits it to the host computer 12 for storage, analysis and recording, and finally outputs the vehicle surface pressure pulsation measurement result. As Figure 3 shown, a first wiring harness interface 7 is provided on the substrate 4, as Figure 1 shown, the data acquisition module 11 includes a power supply interface 15, a data acquisition sub-module 14, a first communication sub-module 16 and a second wiring harness interface 13 respectively connected to the power supply interface 15. The number of channels of the second wiring harness interface 13 is the same as that of the first wiring harness interface 7. Adopting the form of a wiring harness can make the flow-acoustic pressure pulsation measuring device 10 more miniaturized, easier to fit the surface of the acquisition area, avoid interfering with the flow field, reduce the measurement error caused by directly measuring by penetrating into the airflow, and improve the reliability of test data. The data of the microelectromechanical microphone 5 is transmitted to the data acquisition sub-module 14 through the first wiring harness interface 7 and the second wiring harness interface 13 in sequence, and then transmitted to the host computer 12 through the first communication sub-module 16. In a preferred embodiment, a second oncoming flow guiding structure 6 is provided at the front end of the first wiring harness interface 7, and its function is similar to that of the first oncoming flow guiding structure 1.

[0055] The host computer 12 includes a power supply sub-module 18, a second communication sub-module 17, a storage unit 19, a measurement unit 20 and a display unit 21 respectively connected to the power supply sub-module 18. The power supply sub-module 18 is connected to the power supply interface 15. The data of the microelectromechanical microphone 5 is transmitted to the storage unit 19 through the first communication sub-module 16 and the second communication sub-module 17 in sequence. The interface between the first communication sub-module 16 and the second communication sub-module 17 is TCP / IP or USB. The measurement software is stored in the measurement unit 20. The functions of the measurement software include realizing communication, realizing working condition naming, measurement module selection, sampling setting, data recording, data processing and data output. When setting the measurement unit 20, select the corresponding array type according to the setting of the flow-acoustic pressure pulsation measuring device 10, name the working condition according to the actual needs, and send a data recording instruction to collect the data sensed by the flow-acoustic pressure pulsation measuring device 10 through the data acquisition module 11 and store the data in the storage unit 19 through the second communication sub-module 17, and at the same time display it synchronously on the display unit 21, and the interface is as Figure 5As shown. After the measurement is completed, the required operating condition data can be exported and stored in the specified path according to the user's requirements through the data output instruction.

[0056] Compared with the prior art, the present invention has the following advantages:

[0057] (1) Compact structure: The spacing between the microphones is small, enabling the measurement of high-frequency noise and effectively expanding the noise measurement range.

[0058] (2) Small flow field interference: The MEMS microphone array device is provided with a flow guiding structure, effectively reducing the flow interference caused by the physical structure of the test device and improving the test accuracy.

[0059] (3) High integration: Integrating a polysilicon MEMS microphone array, data acquisition and processing, and a host computer test software to achieve integrated application and output, improving the test efficiency.

[0060] (4) High accuracy of test data: The turbulent pressure pulsation measurement area and the sound pressure pulsation measurement area are designed and distinguished on the substrate to achieve accurate positioning of the air flow velocity and direction. At the same time, a film design that effectively suppresses self-noise is covered, making the data measured in the sound pressure pulsation measurement area more accurate.

[0061] (5) Wide range of applicable scenarios: The geometric structure of the present invention is compact and the host computer carrier form has high compatibility. Mobile devices such as tablets or laptops can be used, and it takes into account both in-lab measurements and road measurements.

[0062] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. Obviously, those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A vehicle surface pressure pulsation measurement system, characterized in that: It comprises a flow-acoustic pressure pulsation measuring device (10), a data acquisition module (11) and a host computer (12) which are connected in sequence; The flow-acoustic pressure pulsation measuring device (10) has an aerodynamic shape with a variable curvature, and comprises a substrate (4) and a turbulent pressure pulsation measuring area (2) and an acoustic pressure pulsation measuring area (3) arranged on the substrate (4); the upper surfaces of the turbulent pressure pulsation measuring area (2) and the acoustic pressure pulsation measuring area (3) are located on the same horizontal plane, and both of them comprise a plurality of micro-electromechanical microphones (5) designed and arranged according to an optimal spacing range, and the optimal spacing range is calculated according to wave number-frequency spectrum measurement requirements; the micro-electromechanical microphones (5) in the turbulent pressure pulsation measuring area (2) are arranged in a triangular shape, and the direction indicated by the apex angle of the triangle faces the wind; the micro-electromechanical microphones (5) in the acoustic pressure pulsation measuring area (3) are arranged in an array, and all the micro-electromechanical microphones (5) are attached with an acoustic coating (9) on the measuring surface of the substrate (4); The data acquisition module (11) is used to acquire data of all micro-electromechanical microphones (5) in the flow-acoustic pressure pulsation measurement device (10) in real time through wiring, and transmit the data to the host computer (12); The host computer (12) is used to store, analyze and record the acquired data, and outputs the vehicle surface pressure pulsation measurement results.

2. A vehicle surface pressure pulsation measurement system according to claim 1, characterized in that: The windward end of the base plate (4) is provided with a streamlined first incoming flow guide structure (1), so that the flow-acoustic pressure pulsation measuring device (11) has an aerodynamic shape.

3. A vehicle surface pressure pulsation measurement system according to claim 1, characterized in that: The substrate (4) is made of a flexible material, so that the curvature of the flow-acoustic pressure pulsation measuring device (11) is variable.

4. A vehicle surface pressure pulsation measurement system according to claim 1, characterized in that: The specific process of designing and arranging the micro-electromechanical microphone (5) according to the optimal spacing range is as follows: In the turbulent pressure pulsation measurement area (2), the spacing d1 of the micro-electromechanical microphones (5) satisfies the following formula: d1=U / (m·n·f) Among them, U represents the incoming flow velocity, m represents the number of sampling points of one wavelength, n represents the sampling multiple, and f represents the turbulent pressure pulsation frequency; In the sound pressure pulsation measurement area (3), the spacing d2 of the micro-electromechanical microphones (5) satisfies the following formula: d2=c / (m·n·f) Here, c represents the speed of sound propagation.

5. A vehicle surface pressure pulsation measurement system according to claim 4, characterized in that: When the micro-electromechanical microphones (5) in the sound pressure pulsation measurement area (3) are arranged in a two-dimensional array, the spacing between the micro-electromechanical microphones (5) includes a component d in the x direction. x and the component d in the y direction y : d x =c / (m·n·f x ) d y =c / (m·n·f y ) Among them, f x 、f y are the frequency components of the sound wave in the x and y directions respectively.

6. A vehicle surface pressure pulsation measurement system according to claim 1, characterized in that: In the sound pressure pulsation measurement area (3), the measurement holes of all micro-electromechanical microphones (5) are within one measurement plane.

7. A vehicle surface pressure pulsation measurement system according to claim 1, characterized in that: The substrate (4) is provided with a first wiring interface (7), the data acquisition module (11) comprises a power supply interface (15) and a data acquisition submodule (14) respectively connected to the power supply interface (15), a first communication submodule (16) and a second wiring interface (13), the number of channels of the second wiring interface (13) being the same as that of the first wiring interface (7), the data of the micro-electromechanical microphone (5) being transmitted to the data acquisition submodule (14) through the first wiring interface (7) and the second wiring interface (13) in sequence, and then transmitted to the host computer (12) through the first communication submodule (16).

8. A vehicle surface pressure pulsation measurement system according to claim 7, characterized in that: A streamlined second incoming flow guiding structure (6) is provided at the front end of the first wiring interface (7).

9. A vehicle surface pressure pulsation measurement system according to claim 7, characterized in that: The host computer (12) comprises a power supply submodule (18) and a second communication submodule (17) respectively connected to the power supply submodule (18), a storage unit (19), a measuring unit (20) and a display unit (21); the power supply submodule (18) is connected to the power supply interface (15); the data of the micro-electromechanical microphone (5) is transmitted to the storage unit (19) in sequence through the first communication submodule (16) and the second communication submodule (17); when the measuring unit (20) is set, the corresponding array type is selected according to the setting of the flow-acoustic pressure pulsation measuring device (10), the working condition is named according to actual needs, and a data recording instruction is sent, the data sensed by the flow-acoustic pressure pulsation measuring device (10) is collected through the data collection module (11), and the data is stored in the storage unit (19) through the second communication submodule (17), and is synchronously displayed on the display unit (21); after the measurement is completed, the required working condition data is exported according to the requirements through the data output instruction and stored in the specified path.

10. A vehicle surface pressure pulsation measurement system according to claim 9, characterized in that: The interface used between the first communication submodule (16) and the second communication submodule (17) is TCP / IP or USB.

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