Detection method of exhaust system and detection equipment of exhaust system

Abstract

The embodiment of the invention discloses a detection method of an exhaust system and detection equipment of the exhaust system. The detection method of the exhaust system comprises the steps of obtaining a first noise signal; determining a target device generating the first noise signal according to the first noise signal; a simulation device is designed according to the target device, the simulation device comprises at least two detachable sub-modules, and the sub-modules are assembled into the simulation device; acquiring a second noise signal generated by each sub-module of the simulation device; and according to the second noise signal, determining a target sub-module generated by the noise. According to the technical scheme provided by the embodiment of the invention, the positioning of the noise of the exhaust system is realized, and the noise detection precision of the exhaust system is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of vehicle noise performance testing, and in particular to a detection method and detection equipment for an exhaust system. Background Art

[0002] As vehicles become more commonplace, users are demanding higher performance from various vehicle manufacturers. As electric vehicles become increasingly popular, the size and diameter of exhaust systems are shrinking due to the increasing size of their batteries. This results in higher airflow velocities within the exhaust system, creating higher noise levels within the vehicle, impacting passenger comfort.

[0003] Existing methods for troubleshooting high-frequency noise in exhaust systems often require verification by mounting the entire vehicle. Since the exhaust system is located under the vehicle body, personnel cannot confirm the noise generated by the exhaust system while the vehicle is in a dynamic state. They can only make a rough judgment based on the subjective evaluation of the occupants and noise test data. However, the exhaust system has a complex structure, and the same muffler in the exhaust system is divided into multiple muffler chambers, and there are also situations where multiple stages of mufflers are continuously connected. Existing noise detection methods for exhaust systems can only determine whether the noise comes from the exhaust system, but cannot locate the specific components that cause the noise, as the exhaust system is located under the vehicle body and the surrounding motors and engines have a greater impact on noise judgment.

[0004] Existing noise detection methods for exhaust systems suffer from poor noise detection accuracy, which has become a technical problem that needs to be urgently addressed in the industry. Summary of the Invention

[0005] Embodiments of the present invention provide an exhaust system detection method and an exhaust system detection device to solve the problem of poor noise detection accuracy in exhaust system noise detection methods.

[0006] In order to achieve the above technical problems, the present invention adopts the following technical solutions:

[0007] An embodiment of the present invention provides a method for detecting an exhaust system, comprising:

[0008] Acquiring a first noise signal of the exhaust system to be tested;

[0009] determining, based on the first noise signal, a target device generating the first noise signal;

[0010] Designing a simulation device according to the target device, wherein the simulation device includes at least two detachable submodules, and assembling the submodules into the simulation device;

[0011] collecting a second noise signal generated by each submodule of the simulation device;

[0012] A target submodule where noise is generated is determined according to the second noise signal.

[0013] Optionally, determining, based on the first noise signal, a target device generating the first noise signal includes:

[0014] performing a spectrum analysis on the first noise signal to determine a frequency of the first noise signal;

[0015] A target device generating noise is determined according to the frequency and timbre of the first noise signal; the exhaust system to be tested includes at least one component, and the target device is at least one component in the exhaust system to be tested.

[0016] Optionally, the simulation device is designed according to the target device, the simulation device includes at least two detachable submodules, and the submodules are assembled into the simulation device, including:

[0017] According to the structural composition of the target device, design at least two submodules that can be assembled into a simulation device;

[0018] The submodules are assembled according to the structure of the target device to obtain an assembled simulation device; wherein the assembled simulation device can be disassembled and assembled at least twice; the simulation device is used to replace the target device in the exhaust system to be tested.

[0019] Optionally, determining a target submodule generating noise according to the second noise signal includes:

[0020] determining, according to the second noise signal, a submodule that generates the second noise signal;

[0021] performing a noise silencing process on the submodule generating the second noise signal;

[0022] collecting a third noise signal of the submodule after the noise cancellation process;

[0023] A target submodule for generating noise is determined according to the frequency of the second noise signal and the third noise signal.

[0024] Optionally, the determining a target submodule for noise generation according to the frequency of the second noise signal and the third noise signal includes:

[0025] performing a spectrum analysis on the second noise signal to determine a frequency of the second noise signal;

[0026] When the frequency of the second noise signal is the same as the frequency of the first noise signal and the third noise signal disappears, the submodule generating the second noise signal is determined to be the target submodule.

[0027] Optionally, performing noise cancellation processing on the submodule generating the second noise signal includes:

[0028] The holes, gaps or chambers with a volume smaller than a preset volume in the submodule generating the second noise signal are blocked.

[0029] Optionally, obtaining a first noise signal of the exhaust system to be tested includes:

[0030] Place at least three pickups perpendicular to the mass flow direction of the exhaust system to be measured;

[0031] Setting the distance between the microphone and the target device of the exhaust system to be tested to be greater than or equal to 10 cm and less than or equal to 25 cm;

[0032] The first noise signal of the exhaust system to be tested is collected by at least three of the pickups.

[0033] Optionally, before obtaining the first noise signal of the exhaust system to be tested, the method further includes:

[0034] Outputting a target mass flow rate of air to the exhaust system under test through the cold flow test bench; the target mass flow rate is determined by multiplying the mass flow rate calculated from the engine speed and torque under the target noise operating condition by the target test percentage;

[0035] Before collecting the second noise signal generated by each submodule of the simulation device, the method further includes:

[0036] Connecting the simulation device to the exhaust system to be tested and replacing the target device;

[0037] An airflow of the target mass flow rate is introduced into the exhaust system to be tested connected to the simulation device through the cold flow test bench.

[0038] According to another aspect of the present invention, this embodiment provides an exhaust system detection device, comprising:

[0039] An acquisition module, configured to acquire a first noise signal of the exhaust system to be tested;

[0040] a frequency analysis module, configured to determine, based on the first noise signal, a target device generating the first noise signal;

[0041] a simulation device design module, configured to design a simulation device according to the target device, wherein the simulation device comprises at least two detachable submodules, and the submodules are assembled into the simulation device;

[0042] The acquisition module is further used to acquire the second noise signal generated by each submodule of the simulation device;

[0043] The noise source determination module is used to determine a target submodule generating noise according to the second noise signal.

[0044] Optionally, the exhaust system testing equipment may also include:

[0045] The cold flow test bench is used to output a target mass flow rate of air to the exhaust system under test.

[0046] The exhaust system detection method provided by an embodiment of the present invention comprises at least two detachable submodules, which are assembled into a simulation device. The submodules of the simulation device are tested, and the second noise signals generated by each submodule of the simulation device are collected. Based on the second noise signals generated by each submodule, the target submodule generating the noise is identified, thereby accurately locating the noise-generating submodule and improving noise detection accuracy. Furthermore, the exhaust system detection method provided by this embodiment can precisely locate the noise source, eliminating the noise source before loading the vehicle, thereby preemptively identifying noise risks in the exhaust system and improving the overall noise reduction effect of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in describing the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without any creative work.

[0048] Figure 1 This is a flow chart of a method for detecting an exhaust system provided by an embodiment of the present invention;

[0049] Figure 2 is a flow chart of another exhaust system detection method provided by an embodiment of the present invention;

[0050] Figure 3 is a flow chart of another exhaust system detection method provided by an embodiment of the present invention;

[0051] Figure 4 This is a flow chart of another exhaust system detection method provided by an embodiment of the present invention;

[0052] Figure 5 This is a detailed flow chart of step S404 of an exhaust system detection method provided by an embodiment of the present invention;

[0053] Figure 6This is a flow chart of another exhaust system detection method provided by an embodiment of the present invention;

[0054] Figure 7 is a schematic diagram of a detection device for an exhaust system provided by an embodiment of the present invention;

[0055] Figure 8 This is a flow chart of another exhaust system detection method provided by an embodiment of the present invention;

[0056] Figure 9 This is a flow chart of another exhaust system detection method provided by an embodiment of the present invention;

[0057] Figure 10 is a schematic diagram of another exhaust system detection device provided by an embodiment of the present invention;

[0058] Figure 11 Schematic diagram of another exhaust system detection device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0059] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0060] Based on the above technical problems, this embodiment proposes the following solutions:

[0061] Figure 1 This is a flow chart of an exhaust system detection method provided by an embodiment of the present invention. Figure 1 , the exhaust system detection method provided by the embodiment of the present invention includes:

[0062] S101: Acquire a first noise signal of an exhaust system to be tested.

[0063] Specifically, the exhaust system to be tested includes at least one silencer and an exhaust pipe connected to the silencer. A sensor can be provided to detect the exhaust system to be tested and generate a first noise signal. Exemplarily, the sensor can include a microphone. The microphone can be a free-field microphone. The number of microphones can be single or multiple. The microphone can convert noise into an electrical signal. An acquisition card can be connected to the microphone, and the acquisition card collects the electrical signal output by the microphone as the first noise signal. The acquisition card and the microphone together constitute an acquisition module.

[0064] S102: Determine, according to the first noise signal, a target device generating the first noise signal.

[0065] Specifically, when a pickup corresponding to each device in the exhaust system under test collects a first noise signal, the device in the exhaust system under test corresponding to the pickup can be used as a target device generating the first noise signal. Exemplarily, the target device may include a muffler, adapter flange, and exhaust pipe of the exhaust system under test. The muffler may include a front-stage muffler and a rear-stage muffler.

[0066] S103 . Design a simulation device according to the target device, wherein the simulation device includes at least two detachable submodules, and assemble the submodules into the simulation device.

[0067] Specifically, the assembled simulation device is identical in appearance and function to the target device. The simulation device includes at least two detachable submodules. This arrangement facilitates repeated testing to locate the submodule that generates the noise.

[0068] S104: Collect second noise signals generated by the submodules of the simulation device.

[0069] Specifically, the assembled simulation device is connected to the exhaust system to be tested, and the second noise signals generated by the submodules of the simulation device are collected.

[0070] S105 : Determine a target submodule where noise is generated according to the second noise signal.

[0071] Specifically, the second noise signal can be compared with the first noise signal. If the second noise signal has the same frequency and timbre as the first noise signal, it can be determined that the first noise signal of the target device is generated by a submodule of the target device. The submodule generating the second noise signal is determined as the target noise-generating submodule.

[0072] The exhaust system detection method provided in this embodiment comprises at least two detachable submodules, which are assembled into a simulation device. The submodules are tested, and the second noise signals generated by each submodule of the simulation device are collected. Based on the second noise signals generated by each submodule, the target submodule generating the noise is identified, accurately locating the noise-generating submodule and thus improving noise detection accuracy. Furthermore, the exhaust system detection method provided in this embodiment can precisely locate the noise source, eliminating the noise source before installing it on a vehicle. This allows for early identification of noise risks in the exhaust system, thereby improving the overall noise reduction effect of the vehicle.

[0073] Optional, Figure 2 This is a flow chart of another exhaust system detection method provided by an embodiment of the present invention. Figure 2 , the exhaust system detection method provided by the embodiment of the present invention includes:

[0074] S101: Acquire a first noise signal of an exhaust system to be tested.

[0075] S201: Perform spectrum analysis on the first noise signal to determine the frequency of the first noise signal.

[0076] Specifically, the frequency spectrum of the first noise signal collected by the microphone can be analyzed by the signal analysis module and the frequency analysis software of the signal analysis module to determine the frequency of the first noise signal.

[0077] S202: Determine a target device generating noise based on the frequency and timbre of the first noise signal; the exhaust system to be tested includes at least one component, and the target device is at least one component in the exhaust system to be tested.

[0078] Specifically, the matching degree between the frequency of the first noise signal and the timbre of the first noise signal is determined based on empirical values ​​or a table lookup to determine the target device generating the noise.

[0079] S103 . Design a simulation device according to the target device, wherein the simulation device includes at least two detachable submodules, and assemble the submodules into the simulation device.

[0080] S104: Collect second noise signals generated by the submodules of the simulation device.

[0081] S105 : Determine a target submodule where noise is generated according to the second noise signal.

[0082] The exhaust system detection method provided in this embodiment can further improve the accuracy of locating the noise type and noise source of the first noise signal by performing frequency analysis on the first noise signal, thereby further improving the detection accuracy of the exhaust system to be tested.

[0083] Optional, Figure 3 This is a flow chart of another exhaust system detection method provided by an embodiment of the present invention. Figure 3 , the exhaust system detection method provided by the embodiment of the present invention includes:

[0084] S101: Acquire a first noise signal of an exhaust system to be tested.

[0085] S102: Determine, according to the first noise signal, a target device generating the first noise signal.

[0086] S301 . Design at least two submodules that can be assembled into a simulation device according to the structural composition of the target device.

[0087] Specifically, the submodule is a component of the target device that can be disassembled and assembled repeatedly.

[0088] S302. Assemble the submodules according to the structure of the target device to obtain an assembled simulation device; wherein the assembled simulation device can be disassembled and assembled at least twice; the simulation device is used to replace the target device in the exhaust system to be tested.

[0089] Specifically, the components can be disassembled repeatedly and tested one by one, thereby conducting noise source testing on each component and accurately locating the component that generates the noise.

[0090] S104: Collect second noise signals generated by the submodules of the simulation device.

[0091] S105 : Determine a target submodule where noise is generated according to the second noise signal.

[0092] Optional, Figure 4 This is a flow chart of another exhaust system detection method provided by an embodiment of the present invention. Figure 4 The exhaust system detection method provided in this embodiment includes:

[0093] S101: Acquire a first noise signal of an exhaust system to be tested.

[0094] S102: Determine, according to the first noise signal, a target device generating the first noise signal.

[0095] S103 . Design a simulation device according to the target device, wherein the simulation device includes at least two detachable submodules, and assemble the submodules into the simulation device.

[0096] S104: Collect second noise signals generated by the submodules of the simulation device.

[0097] S401: Determine, according to the second noise signal, a submodule that generates the second noise signal.

[0098] Specifically, the frequency and timbre of the second noise signal are used to locate the submodule that generates the second noise signal. For example, if the timbre of the second noise signal is "howling," the timbre of the second noise signal can be determined through subjective evaluation. The frequency of the second noise signal can be determined by analyzing it using a signal analysis module.

[0099] S402: Perform noise cancellation processing on the submodule that generates the second noise signal.

[0100] Specifically, since noise is easily generated at small gaps or holes of the target device under the action of an airflow of a preset mass flow rate, the small gaps or holes of the submodule generating the second noise signal are silenced.

[0101] S403: Collect the third noise signal of the submodule after the noise cancellation process.

[0102] Specifically, an airflow of a preset mass flow rate is introduced again into the exhaust system to be tested connected to the submodule after the noise reduction treatment, and then a third noise signal of the submodule after the noise reduction treatment is collected.

[0103] S404: Determine a target submodule generating noise according to the frequency of the second noise signal and the third noise signal.

[0104] Specifically, when the third noise signal does not include a noise signal having the same frequency as the second noise signal, it indicates that the submodule after the noise cancellation process is the target submodule corresponding to the second noise signal.

[0105] If the frequency of the third noise signal is the same as the frequency of the second noise signal, it indicates that the third noise signal still exists. The simulation device is disassembled and assembled repeatedly, and steps S401 to S404 are used to determine the target submodule for the next submodule.

[0106] Optionally, based on the above embodiment, Figure 5 This is a detailed flow chart of step S404 of an exhaust system detection method provided by an embodiment of the present invention. Figure 5 Based on the above embodiments, the exhaust system detection method provided in this embodiment provides an optional implementation of step S404 in the above embodiments. S404, determining the target submodule for noise generation based on the frequency of the second noise signal and the third noise signal, may include:

[0107] S4041: Perform spectrum analysis on the second noise signal to determine the frequency of the second noise signal.

[0108] Specifically, a spectrum analyzer or host computer software may be used to perform spectrum analysis on the second noise signal to generate the frequency of the second noise signal.

[0109] S4042: When the frequency of the second noise signal is the same as the frequency of the first noise signal and the third noise signal disappears, determine that the submodule generating the second noise signal is the target submodule.

[0110] Specifically, if the frequency of the second noise signal of the simulated device is the same as the frequency of the noise signal of the target device, this indicates that the submodule corresponding to the second noise signal is the noise-generating submodule. By performing a noise cancellation process on the submodule generating the second noise signal, if the third noise signal of the submodule disappears after the noise cancellation process, this indicates that the noise source of the submodule has been eliminated. In this way, the submodule generating the second noise signal can be determined to be the target submodule.

[0111] Optionally, based on the above embodiments, the exhaust system detection method provided in this embodiment is different from the above embodiments in that step S402 in the above embodiments, silencing the submodule that generates the second noise signal, may include: sealing the holes, gaps or chambers with a volume smaller than a preset volume in the submodule that generates the second noise signal.

[0112] Specifically, since the exhaust system is an important part of the vehicle's power system, it is mainly used to remove engine exhaust gas and reduce engine noise. As high-temperature and high-speed gas flows through the entire exhaust system, when the flow rate of the airflow reaches a certain level, it can stimulate small holes, small chambers, etc. to form high-frequency howling. The principle is similar to that of a flute, producing high-frequency howling noise. The small holes are often located on the baffles and end covers of the muffler and are visually visible. The diameter of the small holes is between 2mm and 3mm and is used to reduce noise and discharge water produced by engine combustion. A small chamber refers to a small local space formed by the overlap of two or more sheet metals. The internal holes and small chambers in the submodule that generates the second noise signal can be sealed with pliers and high-viscosity grease.

[0113] Optional, Figure 6 This is a flow chart of another exhaust system detection method provided by an embodiment of the present invention. Figure 7 This is a schematic diagram of an exhaust system detection device provided by an embodiment of the present invention. Figure 6 and Figure 7 The exhaust system detection method provided in this embodiment includes:

[0114] S601 , dispose at least three microphones 6 perpendicular to the mass flow direction of the exhaust system 10 to be measured.

[0115] Specifically, providing at least three microphones 6 allows for simultaneous detection of at least three different devices in the exhaust system 10 under test, thereby improving testing efficiency. For example, the exhaust system 10 under test may include components such as a pre-muffler 3, a post-muffler 4, and the tail end of the exhaust pipe. Positioning the at least three microphones 6 perpendicular to the mass flow direction of the exhaust system 10 under test further improves the sensitivity of the signals collected by the microphones 6.

[0116] S602: Set the distance between the microphone 6 and the target device of the exhaust system 10 to be greater than or equal to 10 cm and less than or equal to 25 cm.

[0117] Specifically, if the distance between the microphone 6 and the target device in the exhaust system 10 under test is too great, noise may not be detected or the detected signal may be weak. If the distance between the microphone 6 and the target device in the exhaust system 10 under test is too close, noise interference such as vibration from the exhaust system 10 under test may be detected. Setting the distance between the microphone 6 and the target device in the exhaust system 10 under test to be greater than or equal to 10 cm and less than or equal to 25 cm allows the microphone 6, such as a microphone, to accurately pick up noise signals, thereby further improving the detection accuracy of the exhaust system 10.

[0118] S603 : Collect the first noise signal of the exhaust system to be tested through at least three of the microphones 6 .

[0119] Specifically, such an arrangement can improve the test efficiency of the exhaust system 10 to be tested.

[0120] S102: Determine, according to the first noise signal, a target device generating the first noise signal.

[0121] S103 . Design a simulation device according to the target device, wherein the simulation device includes at least two detachable submodules, and assemble the submodules into the simulation device.

[0122] S104: Collect second noise signals generated by the submodules of the simulation device.

[0123] S105 : Determine a target submodule where noise is generated according to the second noise signal.

[0124] It should be noted that the acquisition module may include a microphone 6 and an acquisition card 5, which is not limited here.

[0125] Optional, Figure 8 This is another flow chart of an exhaust system detection method provided by an embodiment of the present invention. Figure 7 and Figure 8 The exhaust system detection method provided in this embodiment includes:

[0126] S701. Output a target mass flow rate of airflow to the exhaust system to be tested through the cold flow test bench 1; the target mass flow rate is determined by multiplying the mass flow rate calculated from the engine speed and torque under the target noise condition by the target test percentage.

[0127] Specifically, the target noise operating conditions may include the operating conditions complained by the whole vehicle. The target test percentage may include, for example, ±30%. ±30% of the mass flow rate calculated from the engine speed and torque under the target noise operating conditions may be used as the target mass flow rate of the cold flow test bench 1 as the test range for testing. The cold flow test bench 1 replaces the whole vehicle to evaluate the noise, which can greatly improve the efficiency of the test. It is also possible to simulate the target mass flow rate of the airflow output by the engine to the exhaust system 10 to be tested in advance through the cold flow test bench 1 before the exhaust system 10 to be tested is assembled to the whole vehicle, and perform a simulated noise test. In combination with the target device that uses the loose parts of the simulation device instead of the assembly parts, it is convenient to repeat the test of each sub-component of the simulation device, further improving the test efficiency and detection accuracy of the noise detection of the exhaust system 10 to be tested.

[0128] S101 : Acquire a first noise signal of the exhaust system 10 to be tested.

[0129] S102: Determine, according to the first noise signal, a target device generating the first noise signal.

[0130] S103 . Design a simulation device according to the target device, wherein the simulation device includes at least two detachable submodules, and assemble the submodules into the simulation device.

[0131] S702 , connecting the simulation device to the exhaust system to be tested and replacing the target device; introducing the target mass flow rate of airflow into the exhaust system to be tested connected to the simulation device through the cold flow test bench.

[0132] S104: Collect second noise signals generated by the submodules of the simulation device.

[0133] S105 : Determine a target submodule where noise is generated according to the second noise signal.

[0134] It should be noted that before outputting the target mass flow rate to the exhaust system under test via the cold flow test bench 1, it is also possible to first confirm whether the exhaust system under test has noise issues. For example, the noise signal of the exhaust system under test with noise issues can be analyzed using noise analysis software to determine the frequency range of the noise source, thereby preliminarily determining which exhaust system under test has noise issues and requires exhaust system testing.

[0135] An optional implementation method, Figure 9 This is a flow chart of another exhaust system detection method provided by an embodiment of the present invention. Figure 9 The exhaust system detection method provided in this embodiment includes the following steps.

[0136] S1. Build the cold flow test bench.

[0137] S2. Arrange the microphone according to the muffler structure.

[0138] Specifically, the microphone is an optional device of the sound pickup.

[0139] S3, cold flow test bench input mass flow rate.

[0140] Specifically, the mass flow rate of the airflow inputted into the cold flow test bench may be a target mass flow rate determined according to the frequency or timbre of the noise, and the target mass flow rate may correspond to the speed of the engine.

[0141] S4. Start objective testing and subjective evaluation.

[0142] Specifically, objective testing involves acquiring a first noise signal from the exhaust system to be tested and performing frequency analysis on the first noise signal. Subjective evaluation involves evaluating the timbre of the first noise signal, such as howling.

[0143] S5. Determine the noise area by combining subjective and objective evaluations.

[0144] S6. Replace the parts that make abnormal noise.

[0145] Specifically, the parts causing abnormal noise refer to detachable submodules of the simulation device.

[0146] S7. Seal small cavities, holes, and gaps in the designed structure.

[0147] Specifically, the design structure refers to submodules.

[0148] S8. Start objective testing and subjective evaluation.

[0149] Specifically, the objective testing in this step involves obtaining a second noise signal from each submodule of the exhaust system simulation device under test and performing frequency analysis on the second noise signal; obtaining a third noise signal from the blocked submodule of the exhaust system simulation device under test and performing frequency analysis on the third noise signal. The subjective evaluation in this step can include the timbre of the third noise signal. If there is a howling sound, step S7 is executed; if not, step S9 is executed.

[0150] S9. Loading evaluation.

[0151] Specifically, after determining the target submodule, the target device is designed or blocked with reference to the simulation device, and then installed on the vehicle, and then tested after installation.

[0152] Figure 10 This is a schematic diagram of another exhaust system detection device provided by an embodiment of the present invention. Figure 10 This embodiment provides an exhaust system detection device, including:

[0153] The acquisition module 81 is configured to acquire a first noise signal from the exhaust system to be tested.

[0154] The frequency analysis module 82 is configured to determine a target device generating the first noise signal based on the first noise signal.

[0155] The simulation device design module 83 is used to design a simulation device according to the target device, wherein the simulation device includes at least two detachable sub-modules, and the sub-modules are assembled into the simulation device.

[0156] The acquisition module 81 is further configured to acquire the second noise signal generated by each submodule of the simulation device.

[0157] The noise source determination module 84 is configured to determine a target submodule generating noise according to the second noise signal.

[0158] Optional, Figure 11 This is a schematic diagram of another exhaust system detection device provided by an embodiment of the present invention. Figure 11 The exhaust system detection equipment also includes: a cold flow test bench 91, which is used to output an airflow with a target mass flow rate to the exhaust system to be tested.

[0159] The exhaust system detection device provided in this embodiment is provided with at least two detachable submodules and each submodule is assembled into a simulation device. By testing each submodule of the simulation device, the submodule generating noise can be accurately located, thereby improving the noise detection accuracy. In addition, the noise-generating target submodule can be silenced, such as by blocking the air gap, to eliminate the noise generated by the target submodule, thereby accurately locating the noise source position. Before the vehicle is loaded, the noise source is eliminated, thereby identifying the noise risk of the exhaust system in advance, thereby improving the overall noise reduction effect of the vehicle. Furthermore, by setting up a cold flow test bench, an airflow of a target mass flow rate is output to the exhaust system to be tested. The cold flow test bench can effectively simulate the high-frequency whistling sound level of the exhaust system of the whole vehicle. The cold flow test bench replaces the whole vehicle to evaluate noise, providing feasibility for repeatedly disassembling the simulation device to locate the noise source. In addition, the development verification (DV) test items can be added during the development of new parts to facilitate the early identification of whistling noise risks, which can effectively improve the efficiency of testing the exhaust system to be tested and reduce production costs.

[0160] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for detecting an exhaust system, characterized in that: include: Acquiring a first noise signal of the exhaust system to be tested; determining, based on the first noise signal, a target device generating the first noise signal; Designing a simulation device according to the target device, wherein the simulation device includes at least two detachable submodules, and assembling the submodules into the simulation device; collecting a second noise signal generated by each submodule of the simulation device; A target submodule where noise is generated is determined according to the second noise signal.

2. The method according to claim 1, characterized in that The determining, based on the first noise signal, a target device generating the first noise signal includes: performing a spectrum analysis on the first noise signal to determine a frequency of the first noise signal; A target device generating noise is determined according to the frequency and timbre of the first noise signal; the exhaust system to be tested includes at least one component, and the target device is at least one component in the exhaust system to be tested.

3. The method according to claim 1, characterized in that The simulation device is designed according to the target device, wherein the simulation device includes at least two detachable submodules, and the submodules are assembled into the simulation device, including: According to the structural composition of the target device, design at least two submodules that can be assembled into a simulation device; The submodules are assembled according to the structure of the target device to obtain an assembled simulation device; wherein the assembled simulation device can be disassembled and assembled at least twice; the simulation device is used to replace the target device in the exhaust system to be tested.

4. The method according to claim 1, wherein The step of determining a target submodule for noise generation according to the second noise signal includes: determining, according to the second noise signal, a submodule that generates the second noise signal; performing a noise silencing process on the submodule generating the second noise signal; collecting a third noise signal of the submodule after the noise cancellation process; A target submodule for generating noise is determined according to the frequency of the second noise signal and the third noise signal.

5. The method according to claim 4, characterized in that The target submodule for determining noise generation according to the frequency of the second noise signal and the third noise signal includes: performing a spectrum analysis on the second noise signal to determine a frequency of the second noise signal; When the frequency of the second noise signal is the same as the frequency of the first noise signal and the third noise signal disappears, the submodule generating the second noise signal is determined to be the target submodule.

6. The method according to claim 4, characterized in that The performing noise elimination processing on the submodule generating the second noise signal includes: The holes, gaps or chambers with a volume smaller than a preset volume in the submodule generating the second noise signal are blocked.

7. The method according to any one of claims 1 to 6, characterized in that The obtaining of a first noise signal of the exhaust system to be tested includes: Place at least three pickups perpendicular to the mass flow direction of the exhaust system to be measured; Setting the distance between the microphone and the target device of the exhaust system to be tested to be greater than or equal to 10 cm and less than or equal to 25 cm; The first noise signal of the exhaust system to be tested is collected by at least three of the pickups.

8. The method according to any one of claims 1 to 6, characterized in that Before obtaining the first noise signal of the exhaust system to be tested, the method further includes: Outputting a target mass flow rate of air to the exhaust system under test through the cold flow test bench; the target mass flow rate is determined by multiplying the mass flow rate calculated from the engine speed and torque under the target noise operating condition by the target test percentage; Before collecting the second noise signal generated by each submodule of the simulation device, the method further includes: Connecting the simulation device to the exhaust system to be tested and replacing the target device; An airflow of the target mass flow rate is introduced into the exhaust system to be tested connected to the simulation device through the cold flow test bench.

9. An exhaust system detection device, characterized in that: include: An acquisition module, configured to acquire a first noise signal of the exhaust system to be tested; a frequency analysis module, configured to determine, based on the first noise signal, a target device generating the first noise signal; a simulation device design module, configured to design a simulation device according to the target device, wherein the simulation device comprises at least two detachable submodules, and the submodules are assembled into the simulation device; The acquisition module is further used to acquire the second noise signal generated by each submodule of the simulation device; The noise source determination module is used to determine a target submodule generating noise according to the second noise signal.

10. The detection device according to claim 9, characterized in that Also includes: The cold flow test bench is used to output a target mass flow rate of air to the exhaust system under test.

Images