Abnormal noise diagnosis device

Abstract

To provide an abnormal noise diagnostic device capable of discriminating with good accuracy an abnormal noise according to the actuation of a supercharger.SOLUTION: An abnormal noise diagnostic device diagnoses an abnormal noise generated in a vehicle mounted with an internal combustion engine with a supercharger including an air by-pass valve. In the case where a frequency of the abnormal noise is included in a predetermined frequency range, an operation point of the supercharger at the time of the abnormal noise generation is included in an abnormal noise generation region corresponding to the combination of the internal combustion engine and the supercharger, and the vehicle has not decelerated at the time of the abnormal noise generation, it is diagnosed that the abnormal noise caused by a pressure pulsation in the supercharger has been generated, In the case where the frequency of the abnormal noise is included in the frequency range, the operation point of the supercharger at the time of the abnormal noise generation is included in the abnormal noise generation region corresponding to the combination of the internal combustion engine and the supercharger, and the vehicle has decelerated at the time of the abnormal noise generation, it is diagnosed that the abnormal noise caused by the actuation of the air by-pass valve has been generated.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an abnormal noise diagnosis device that diagnoses abnormal noise generated in a vehicle. [Background technology]

[0002] It has been known that in an internal combustion engine having a supercharger, when the air compressed by the compressor of the supercharger flows backward and passes through the compressor in response to the accelerator pedal being released, an abnormal noise (breath-back noise) is generated (see, for example, Patent Document 1). In such an internal combustion engine, a presurge line is defined as a boundary between an area where the abnormal noise occurs and an area where it does not occur, and the intake air amount is controlled so that the operating point of the supercharger (intake air amount and pressure ratio) does not fall within the area where the abnormal noise occurs, thereby making it possible to suppress the generation of the abnormal noise. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-165124 Summary of the Invention [Problem to be solved by the invention]

[0004] However, abnormal noises caused by the operation of the turbocharger may occur in a non-occurrence area based on the above-mentioned presurge line, and it is difficult to determine based on the presurge line whether an abnormal noise generated in a vehicle is caused by the operation of the turbocharger.

[0005] Therefore, a main object of the present disclosure is to accurately identify abnormal noises that accompany the operation of a supercharger. [Means for solving the problem]

[0006] The abnormal noise diagnosis device disclosed herein is an abnormal noise diagnosis device that diagnoses abnormal noise generated in a vehicle equipped with an internal combustion engine equipped with a turbocharger that includes an air bypass valve, and diagnoses that abnormal noise has occurred due to pressure pulsation in the turbocharger if the frequency of the abnormal noise is within a predetermined frequency range, the operating point of the turbocharger at the time the abnormal noise occurred is within an abnormal noise generation region that corresponds to the combination of the internal combustion engine and the turbocharger, and the vehicle is not decelerating when the abnormal noise occurred, and diagnoses that abnormal noise has occurred due to operation of the air bypass valve if the frequency of the abnormal noise is within the frequency range, the operating point of the turbocharger at the time the abnormal noise occurred is within the abnormal noise generation region that corresponds to the combination of the internal combustion engine and the turbocharger, and the vehicle is decelerating when the abnormal noise occurred.

[0007] Such an abnormal noise diagnosis device makes it possible to accurately identify abnormal noises caused by the operation of the turbocharger. Furthermore, the abnormal noise diagnosis device of the present disclosure may include a diagnosis unit constructed by machine learning so as to diagnose the cause of the abnormal noise based on given information when it is diagnosed that no abnormal noises caused by the operation of the turbocharger are occurring. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram illustrating an abnormal sound diagnosis system including an abnormal sound diagnosis device according to the present disclosure. [Figure 2] 3 is a flowchart showing a series of processes executed by the abnormal sound diagnosis device of the present disclosure. [Figure 3] FIG. 2 is an explanatory diagram showing an abnormal noise generation region where abnormal noise occurs due to the operation of the supercharger. DETAILED DESCRIPTION OF THE INVENTION

[0009] Next, embodiments of the present disclosure will be described with reference to the drawings.

[0010] FIG. 1 is a schematic diagram showing an abnormal sound diagnosis system 1 including a server 20 as an abnormal sound diagnosis device according to the present disclosure. The abnormal sound diagnosis system 1 shown in the figure is used to diagnose the cause of abnormal sounds generated in various vehicles, including a vehicle X. The vehicle X is equipped with an internal combustion engine EG including a supercharger TC that compresses intake air using exhaust gas energy and an intercooler IC that cools the air compressed by the supercharger TC. In this embodiment, the supercharger TC is a turbocharger and includes a turbine wheel Wt rotatably disposed in a turbine housing formed in an exhaust pipe EP, a compressor wheel Wc rotatably disposed in a compressor housing formed in an intake pipe IP, a turbine shaft St that integrally connects the turbine wheel Wt and the compressor wheel Wc, a wastegate valve WGV, and an air bypass valve ABV.

[0011] As shown in FIG. 1, the abnormal sound diagnosis system 1 includes, in addition to a server 20, a mobile terminal 10 capable of exchanging information with the server 20 via communication. The mobile terminal 10 is used by a worker (user of the abnormal sound diagnosis system 1) at a vehicle dealership, repair shop, or the like when responding to a user (owner) of a vehicle X or the like in which an abnormal sound has occurred, or when performing a reproduction test in which the vehicle X or the like is driven (operated) on a roadway or test bench to reproduce the abnormal sound. In this embodiment, the mobile terminal 10 is a smartphone including an SoC, ROM, RAM, an auxiliary storage device (flash memory) M, a touch-panel display 11, a communication module 12 capable of exchanging various information with the server 20 and an electronic control unit (ECU) (not shown) of the vehicle X or the like via wired or wireless communication, a microphone (not shown), and the like. An abnormal sound diagnosis support application (program) is also installed on the mobile terminal 10. As shown in FIG. 1, the mobile terminal 10 includes a medical interview information acquisition unit 13, a sound acquisition unit 14, a vehicle state acquisition unit 15, a calculation processing unit 16, an extraction unit 17, and a display control unit 18, which are constructed in cooperation with an abnormal sound diagnosis support application (software) and hardware such as the SoC of the mobile terminal 10.

[0012] The medical inquiry information acquisition unit 13 acquires medical inquiry information indicating the state of the vehicle X, etc., at the time of the occurrence of an abnormal noise, provided by a user of the vehicle X, etc., via the display unit 11. The medical inquiry information includes vehicle identification information including the vehicle model, vehicle identification number (chassis number), etc., order, date and time of occurrence, occurrence frequency, location of the abnormal noise, type of sound (onomatopoeia), physical quantities that change while the vehicle X, etc., is traveling, the driving state of the vehicle X, etc., warm-up effects in engine-equipped vehicles, selection items selected by the driver while driving the vehicle X, etc., driving environment information of the vehicle X, etc., and the like, and is input by the above-mentioned worker or the user of the vehicle X, etc. The sound acquisition unit 14 acquires time axis data of the sound (sound pressure) when a reproduction test is performed by the worker. The vehicle state acquisition unit 15 acquires vehicle state data indicating the state of the vehicle X, etc., in synchronization with the acquisition of the time axis data of the sound by the sound acquisition unit 14 when a reproduction test is performed. The vehicle condition data includes a plurality of physical quantities corresponding to items of medical interview information, such as the intake air volume of the internal combustion engine EG, the intake temperature, the atmospheric pressure, and the supercharging pressure of the supercharger TC. The calculation processing unit 16 performs an analysis process of the time axis data of the sound acquired by the sound acquisition unit 14. The extraction unit 17 performs narrowing down of the analysis results by the calculation processing unit 16 according to the selection of the operator, etc. The display control unit 18 controls the display unit 11.

[0013] The server 20, which serves as an abnormal sound diagnosis device, is a computer including a CPU, ROM, RAM, input / output devices, a communication module, etc., and is installed and managed, for example, by the automobile manufacturer that produces the vehicle X, etc. The server 20 has an abnormal sound diagnosis unit 21 that diagnoses abnormal sounds generated in the vehicle X, etc., through cooperation between hardware such as the CPU and a pre-installed abnormal sound diagnosis application. The abnormal sound diagnosis unit 21 includes a neural network (convolutional neural network) as a diagnosis module constructed by supervised learning (machine learning) to diagnose the cause of abnormal sounds generated in the vehicle X, etc., and the part that is the source of the abnormal sound, based on the medical interview information and sound time axis data acquired by the mobile terminal 10.

[0014] When the server 20 detects the occurrence of a new abnormal noise in the vehicle X or the like, the abnormal noise diagnosis unit 21 performs re-learning using the acquired sound time axis data for the new abnormal noise and the details of each item of the medical interview information as training data. The server 20 also includes a storage device 22 that stores an abnormal noise database that stores, for each vehicle model, information on multiple abnormal noises that are known to occur in the vehicle. The abnormal noise database associates each of the multiple abnormal noises with information such as the sound time axis data, the cause of the abnormal noise, the part that is the source of the noise, the details of the medical interview information provided by the user or the like, and measures to resolve the abnormal noise. The server 20 also updates the abnormal noise database based on information acquired from the vehicle X or the like, and information (reports) related to newly discovered abnormal noises sent from the automobile manufacturer (developer, etc.), vehicle dealership, repair shop, etc.

[0015] Next, a procedure for diagnosing an abnormal noise occurring in vehicle X using the abnormal noise diagnosis system 1 will be described. When a worker at a vehicle dealership or the like is requested by a user or the like of vehicle X to resolve an abnormal noise, the worker listens to interview information from the user or the like and then performs a reproduction test to acquire information necessary for diagnosing the abnormal noise. To perform the reproduction test, the worker connects the mobile terminal 10 to an electronic control device of vehicle X and places (fixes) the mobile terminal 10 or an external microphone connected to the mobile terminal 10 in an appropriate location of vehicle X (for example, the passenger compartment or the engine compartment). The worker also launches an abnormal noise diagnosis support application and turns on the start switch of vehicle X. Accordingly, the mobile terminal 10 acquires information such as the vehicle identification number or chassis number of vehicle X from the electronic control device. The worker also taps the recording start button displayed on the display unit 11 and drives (operates) vehicle X on a roadway or a test stand to reproduce the driving conditions in which the abnormal noise occurred based on the interview information from the user or the like of vehicle X.

[0016] While the vehicle X is running (operating), the sound acquisition unit 14 of the mobile terminal 10 acquires time axis data of the sound emitted from the vehicle X at predetermined time intervals (micro time intervals) and stores the data in the auxiliary storage device M. In addition, the vehicle state acquisition unit 15 acquires vehicle state data specified by the worker in accordance with the medical interview information from the electronic control device of the vehicle X at predetermined time intervals (micro time intervals) in synchronization with the acquisition of the sound time axis data by the sound acquisition unit 14, and stores the vehicle state data in the auxiliary storage device M. When the worker taps the recording stop button displayed on the display unit 11, the acquisition of the sound time axis data and vehicle state data is completed.

[0017] After the reproduction test is completed, the calculation processing unit 16 performs a Short-Time Fourier Transform (STFT) on the time-axis data of the sound to obtain a spectrogram (acoustic spectrogram) showing the relationship between time, frequency, and sound pressure. The display control unit 18 then displays the spectrogram on the display unit 11. In this embodiment, the spectrogram is a color map with the horizontal axis representing time and the vertical axis representing frequency, and color-coding the sound pressure level to show the relationship between time and sound pressure level for each frequency. Furthermore, on the display unit 11, the operator selects (specifies) a range of the spectrogram to be diagnosed (analyzed) by the abnormal sound diagnosis unit 21 (server 20) (hereinafter referred to as the "diagnosis range"). Furthermore, the operator inputs medical interview information into the input screen displayed on the display unit 11. When the operator taps an information transmission button displayed on the display unit 11, the information necessary for diagnosing the abnormal sound is transmitted from the communication module 12 of the mobile terminal 10 to the server 20. In this embodiment, the information transmitted from the mobile terminal 10 to the server 20 includes time axis data of the sound acquired by the sound acquisition unit 14, vehicle state data acquired by the vehicle state acquisition unit 15, medical interview information, and information defining the above-mentioned diagnostic range.

[0018] 2 is a flowchart showing a series of processes executed by the server 20 in response to receiving information from the mobile terminal 10. As shown in the figure, the abnormal sound diagnosis unit 21 of the server 20 acquires sound time axis data, vehicle condition data, medical interview information, and information defining the diagnostic range from the mobile terminal 10 (S100). Then, it acquires the frequency ft of the abnormal sound recognized by the operator from the sound time axis data acquired in step S100 (S110). In step S110, the abnormal sound diagnosis unit 21 extracts characteristic frequencies in the diagnostic range selected by the operator according to a predetermined procedure, and sets the extracted frequency as the abnormal sound frequency ft. Furthermore, the abnormal sound diagnosis unit 21 determines whether the abnormal sound frequency ft acquired in step S110 is equal to or greater than a lower limit frequency f1 (e.g., 300 Hz) and equal to or less than an upper limit frequency f2 (e.g., 3 kHz) (S120). The lower limit frequency f1 and the upper limit frequency f2 are determined in advance through experiments and analyses as the lower limit and upper limit of the frequency of abnormal noise generated due to the operation of the turbocharger TC.

[0019] If the frequency ft of the abnormal sound is within the frequency range from the lower limit frequency f1 to the upper limit frequency f2 (S120: YES), the abnormal sound diagnosis unit 21 acquires the intake air amount, intake temperature, atmospheric pressure, and boost pressure of the internal combustion engine EG within the above diagnosis range from the vehicle condition data acquired in step S100 (S130). Furthermore, based on the vehicle condition data within the above diagnosis range acquired in step S130, the abnormal sound diagnosis unit 21 calculates the intake air amount corrected by the intake temperature and calculates the pressure ratio obtained from the atmospheric pressure and boost pressure (boost pressure / atmospheric pressure) for each acquisition timing of the vehicle condition data within the diagnosis range (S140). Furthermore, the abnormal sound diagnosis unit 21 acquires the vehicle model of vehicle X, the model of the internal combustion engine EG, and the model of the supercharger TC mounted on vehicle X from a vehicle information database stored in the storage device 22 or another server based on the vehicle identification number and the like included in the medical interview information, and reads out from the storage device 22 the abnormal sound generation area corresponding to the combination of the vehicle model, the internal combustion engine EG (model), and the supercharger TC (model) (S150).

[0020] Here, the present inventors have conducted extensive research into abnormal noise generated due to the operation of a turbocharger TC in a vehicle X equipped with an internal combustion engine EG including the turbocharger TC, and as a result have found that abnormal noise is generated due to the operation of the turbocharger TC when the operating point of the turbocharger TC, which is defined by the intake air amount and the pressure ratio, is included in an abnormal noise generation region as shown in Figure 3, which corresponds to a combination of the vehicle model, the internal combustion engine EG, and the turbocharger TC. Based on this, in this embodiment, an abnormal noise generation region defined by the intake air amount and the pressure ratio is determined in advance through experiments and analyses for each of a plurality of combinations of the vehicle model, the internal combustion engine EG, and the turbocharger TC, and is stored in the storage device 22 (abnormal noise database) of the server 20. The abnormal noise generation region can be determined by actually measuring the pressure pulsation of the turbocharger TC alone and calculating a transfer function from the pressure measurement point to the compressor end to determine the volume velocity, which is the forcing force for the abnormal noise.

[0021] Then, the abnormal sound diagnosis unit 21 determines whether or not at least one of the intake air amount and pressure ratio calculated for each acquisition timing of vehicle state data within the diagnosis range in step S140, i.e., at least one of the operating points of the turbocharger TC when an abnormal sound occurs, is within the abnormal sound occurrence region read out in step S150 (S160). If at least one of the operating points of the turbocharger TC when an abnormal sound occurs is within the abnormal sound occurrence region (S160: YES), the abnormal sound diagnosis unit 21 calculates the amount of change in the intake air amount per unit time within the diagnosis range (S170). Here, according to research by the present inventor, it has been found that if the vehicle X is decelerating when the operating point of the turbocharger TC is within the abnormal sound occurrence region, an abnormal sound is generated due to operation of the air bypass valve ABV of the turbocharger TC, and if the vehicle X is not decelerating when the operating point of the turbocharger TC is within the abnormal sound occurrence region, an abnormal sound (hereinafter referred to as a "presurge sound") is generated due to pressure pulsation in the turbocharger TC.

[0022] Therefore, the abnormal sound diagnosis unit 21 determines whether or not the vehicle X is decelerating when the abnormal sound occurs based on the amount of change in the intake air amount calculated in step S170 (S180), and if the vehicle X is decelerating when the abnormal sound occurs (S180: YES), it diagnoses (determines) that the abnormal sound generated in the vehicle X is caused by operation of the air bypass valve ABV of the turbocharger TC (S190).Furthermore, if it is determined that the vehicle X is not decelerating when the abnormal sound occurs based on the amount of change in the intake air amount calculated in step S170 (S180: NO), the abnormal sound diagnosis unit 21 diagnoses (determines) that the abnormal sound generated in the vehicle X is a pre-surge sound caused by pressure pulsation in the turbocharger TC (S195). On the other hand, if the frequency ft of the abnormal sound is not included in the frequency range from the lower limit frequency f1 to the upper limit frequency f2 (S120: NO) and if the operating point of the turbocharger TC at the time of the abnormal sound occurrence is not included in the abnormal sound occurrence region read out in step S150 (S160: NO), the abnormal sound diagnosis unit 21 diagnoses the cause of the abnormal sound occurring in the vehicle X using the neural network based on the information acquired in step S100 (S125).

[0023] After the processing of steps S190, S195, or S125, the abnormal sound diagnosis unit 21 generates a diagnosis result including the name of the abnormal sound, the part that is the source of the abnormal sound, the cause of the abnormal sound, and measures to eliminate the abnormal sound that are read from the storage device 22 (S200). Furthermore, the abnormal sound diagnosis unit 21 transmits the diagnosis result generated in step S200 to the mobile terminal 10 (S210), thereby ending the series of processes in FIG. 2. When the diagnosis result from the server 20 is received by the mobile terminal 10, the diagnosis result is displayed on the display unit 11. This allows the operator to accurately explain the diagnosis result from the server 20 to the user of vehicle X, etc., and promptly proceed with measures to address the abnormal sound.

[0024] As described above, the server 20 serving as the abnormal sound diagnosis device in the abnormal sound diagnosis system 1 diagnoses that a presurge sound caused by pressure pulsation in the supercharger TC has occurred (S195) if the frequency ft of the abnormal sound is within the frequency range from the lower limit frequency f1 to the upper limit frequency f2 (S120: YES), the operating point (intake air amount and pressure ratio) of the supercharger TC at the time the abnormal sound occurred is within the abnormal sound occurrence region corresponding to the combination of the vehicle model, internal combustion engine EG, and supercharger TC (S160: YES), and the vehicle X is not decelerating when the abnormal sound occurred (S180: NO). Furthermore, the server 20 diagnoses that an abnormal sound caused by operation of the air bypass valve ABV has occurred (S190) if the frequency ft of the abnormal sound is within the above frequency range (S120: YES), the operating point of the supercharger TC at the time the abnormal sound occurred is within the above abnormal sound occurrence region (S160: YES), and the vehicle X is decelerating when the abnormal sound occurred (S180: YES). This makes it possible to accurately identify abnormal noises that accompany the operation of the supercharger TC.

[0025] The server 20 also includes an abnormal sound diagnosis unit 21 that is constructed by machine learning so as to diagnose the cause of the abnormal sound based on given information when it is diagnosed that no abnormal sound is occurring due to the operation of the turbocharger TC. This can further improve the versatility of the server 20 and, in turn, the abnormal sound diagnosis system 1. The abnormal sound diagnosis support application installed in the mobile terminal 10 may be installed on a tablet terminal, a personal computer, or the like, and the tablet terminal or the like may be used instead of the mobile terminal 10. Furthermore, some of the functions of the abnormal sound diagnosis unit 21 may be provided in the mobile terminal 10, and the abnormal sound diagnosis system 1 may be configured as a single information processing device such as a personal computer. [Industrial Applicability]

[0026] The invention of the present disclosure is extremely useful for diagnosing abnormal noises that occur in a vehicle equipped with an internal combustion engine equipped with a supercharger that includes an air bypass valve. [Explanation of symbols]

[0027] 1 Abnormal sound diagnosis system, 10 Mobile terminal, 20 Server (abnormal sound diagnosis device), 21 Abnormal sound diagnosis unit, ABV Air bypass valve, EG Internal combustion engine, TC Supercharger, X Vehicle.

Claims

[Claim 1] An abnormal noise diagnosis device for diagnosing abnormal noise generated in a vehicle equipped with an internal combustion engine equipped with a turbocharger including an air bypass valve, an abnormal noise diagnosis device that diagnoses that the occurrence of an abnormal noise is due to pressure pulsation in the supercharger, if the frequency of the abnormal noise is within a predetermined frequency range, the operating point of the supercharger at the time the abnormal noise is generated is within an abnormal noise generation region that corresponds to the combination of the internal combustion engine and the supercharger, and the vehicle is not decelerating when the abnormal noise is generated; and that the occurrence of an abnormal noise is due to operation of the air bypass valve, if the frequency of the abnormal noise is within the frequency range, the operating point of the supercharger at the time the abnormal noise is generated is within the abnormal noise generation region that corresponds to the combination of the internal combustion engine and the supercharger, and the vehicle is decelerating when the abnormal noise is generated.

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