Internal combustion engine noise detection system

Abstract

To provide an abnormal sound determination system for an internal combustion engine, which determines specific abnormal sound generated due to sudden opening of a throttle from among a plurality of kinds of abnormal sound.SOLUTION: An abnormal sound determination system for an internal combustion engine determines abnormal sound generated in the internal combustion engine including a throttle and a surge tank. A processing device included in the abnormal sound determination system, collects the abnormal sound through a microphone, and when the abnormal sound includes a frequency component in a range of several kilohertz as a main component, acquires an opening degree of the throttle and internal pressure of the surge tank, and when the opening degree and the internal pressure satisfy generation conditions of specific abnormal sound generated upon sudden opening of the throttle, determines that the abnormal sound includes the specific abnormal sound.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an abnormal noise detection system for an internal combustion engine. [Background technology]

[0002] BACKGROUND ART There is known a technique for measuring the sound near the throttle of an internal combustion engine and evaluating the intake sound of a vehicle when the internal combustion engine is rotating (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-304658 Summary of the Invention [Problem to be solved by the invention]

[0004] Airflow noise from an internal combustion engine, including vehicle intake noise, can include not only normal airflow noise but also abnormal airflow noise (hereinafter referred to as abnormal noise). There are several types of abnormal noise. When an abnormal noise occurs from a vehicle equipped with an internal combustion engine, workers at the vehicle dealership or repair shop will replace the appropriate part depending on the type of abnormal noise.

[0005] However, there is a problem in that it is difficult to distinguish the specific abnormal noise caused by sudden throttle opening from other abnormal noises. If an operator makes an error in distinguishing the specific abnormal noise, it may lead to replacing the wrong part.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an abnormal noise discrimination system for an internal combustion engine that can discriminate a specific abnormal noise caused by abrupt throttle opening from among a plurality of types of abnormal noise. [Means for solving the problem]

[0007] The abnormal noise detection system for an internal combustion engine according to the present invention is an internal combustion engine abnormal noise detection system that detects abnormal noises generated in an internal combustion engine that includes a throttle and a surge tank. A processing device included in the abnormal noise detection system collects the abnormal noise via a microphone, and if the abnormal noise contains frequency components within a range of several kilohertz as its main components, obtains the throttle opening and the internal pressure of the surge tank, and if the opening and the internal pressure satisfy the conditions for the generation of a specific abnormal noise that occurs due to the sudden opening of the throttle, determines that the specific abnormal noise is included in the abnormal noise.

[0008] In the above configuration, the processing device may determine that the abnormal noise includes another abnormal noise different from the specific abnormal noise when the opening degree and the internal pressure do not satisfy the occurrence condition.

[0009] In the aforementioned configuration, the processing device may display the specific abnormal noise in priority to the other abnormal noises.

[0010] In the aforementioned configuration, the processing device may determine that the occurrence condition is satisfied when the opening degree is equal to or greater than a first threshold value and the internal pressure is equal to or less than a second threshold value.

[0011] In the above configuration, the processing device may include a first processing device provided in a mobile terminal and a second processing device provided in a server device, and the first processing device may collect the abnormal sounds and obtain the opening degree and the internal pressure, and the second processing device may determine that the abnormal sounds include the specific abnormal sound. [Effects of the Invention]

[0012] According to the present invention, it is possible to distinguish a specific abnormal noise caused by sudden throttle opening from a plurality of types of abnormal noise. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram illustrating an example of application of an abnormal noise detection system for an internal combustion engine. [Figure 2]FIG. 2 is a flowchart showing an example of the operation of the abnormal noise detection system for an internal combustion engine. [Figure 3] Figure 3(a) is an example of the data details screen, and Figure 3(b) is an example of the abnormal noise range specification screen. [Figure 4] Fig. 4(a) is an example of an abnormal sound determination map, and Fig. 4(b) is a diagram illustrating an example of a spectrogram including a specific abnormal sound. [Figure 5] Figure 5 is an example of a screen display. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0015] As shown in Fig. 1, the internal combustion engine abnormal noise detection system ST includes a mobile terminal 100 and a server device 200 as processing devices. The mobile terminal 100 may be a smart device such as a smartphone or a tablet terminal, or may be a PC (Personal Computer). The mobile terminal 100 includes a processor and a memory as a first processing device. The server device 200 includes a processor and a memory as a second processing device. The processor includes, for example, a CPU (Central Processing Unit). The memory includes, for example, a RAM (Random Access Memory) and a ROM (Read Only Memory).

[0016] The mobile terminal 100 and the server device 200 are connected via a communication network NW and a mobile base station BS. The communication network NW includes either the Internet or a LAN (Local Area Network), or both. The mobile terminal 100 and the server device 200 transmit and receive various data to and from each other via wireless and wired communications.

[0017] The vehicle 300 is equipped with an internal combustion engine 2. The internal combustion engine 2 includes an internal combustion engine body 4, a surge tank 24, and an electric throttle 26. A piston 6 is disposed in a cylinder 5 of the internal combustion engine body 4. The cylinder 5 is provided with an intake valve 18 that opens and closes between an intake port and a combustion chamber, and an exhaust valve 20 that opens and closes between an exhaust port and a combustion chamber. An intake passage 22 is connected to the intake port of the cylinder 5.

[0018] The surge tank 24 described above is provided in the intake passage 22. An intake pressure sensor 23 is disposed in the surge tank 24. The intake pressure sensor 23 can detect the internal pressure inside the surge tank 24 (hereinafter referred to as surge tank internal pressure). The electric throttle 26 described above is disposed upstream of the surge tank 24. An exhaust path 30 communicates with the exhaust port of the cylinder 5. An air-fuel ratio sensor 32 is attached downstream of the junction of the exhaust path 30.

[0019] Additionally, the internal combustion engine body 4 is provided with an injector 12 that injects fuel into the intake passage 22 and a spark plug 14 that ignites the air-fuel mixture in the combustion chamber. The injector 12 is installed in the intake port and is configured to inject fuel toward the back side of the intake valve.

[0020] The engine ECU (Electronic Control Unit) 40 controls the operation of the internal combustion engine 2. The engine ECU 40 receives input information from various sensors, such as the output KL of the intake pressure sensor 23, which indicates the surge tank pressure. The engine ECU 40 also receives input information from various actuators, such as the throttle motor of the electric throttle 26, from its output. The engine ECU 40 executes a predetermined program stored in ROM based on the input information from the various sensors, and activates the various actuators. For example, the engine ECU 40 calculates a target throttle opening based on the input information, activates the throttle motor, and controls the throttle valve connected to the throttle motor to the target throttle opening. In this way, the engine ECU 40 maintains the surge tank pressure and the throttle opening of the throttle valve. In FIG. 1, the target throttle opening is indicated as "TA."

[0021] The mobile terminal 100 accesses the engine ECU 40 of the vehicle 300 via wireless or wired communication based on the operation of a worker at a vehicle dealership or a maintenance workshop. When the mobile terminal 100 accesses the engine ECU 40, the mobile terminal 100 collects the throttle opening and the surge tank internal pressure as time-series data from the engine ECU 40. In FIG. 1, the mobile terminal 100 collects the throttle opening and the surge tank internal pressure from outside the vehicle 300, but it may also collect these data from inside the vehicle 300.

[0022] Furthermore, the mobile terminal 100 collects abnormal sounds based on the operator's operation. The abnormal sounds are airflow sounds that differ from normal airflow sounds generated in the internal combustion engine 2. These airflow sounds may be called abnormal airflow sounds in contrast to normal airflow sounds. The mobile terminal 100 is equipped with a microphone. When the internal combustion engine 2 is operating, the mobile terminal 100 collects abnormal sounds generated in the internal combustion engine 2 via the microphone. After collecting the throttle opening, surge tank internal pressure, and abnormal sounds, the mobile terminal 100 cooperates with the server device 200 and determines whether the abnormal sounds include a specific abnormal sound that occurs due to the sudden opening of the electric throttle 26, based on the collected throttle opening, surge tank internal pressure, abnormal sounds, etc.

[0023] The operation of the abnormal sound detection system ST will be described with reference to Figures 2 to 5. The abnormal sound detection system ST can be realized by the processor of the mobile terminal 100 and the processor of the server device 200 working together to execute a program according to the flowchart shown in Figure 2.

[0024] First, as shown in Fig. 2, the mobile terminal 100 collects the throttle opening and the surge tank pressure (step S1). The engine ECU 40 stores both the throttle opening and the surge tank pressure as time-series data. The mobile terminal 100 collects some or all of the throttle opening and the surge tank pressure stored as time-series data from the engine ECU 40 in advance. As a result, the mobile terminal 100 stores the time-series throttle opening and the surge tank pressure.

[0025] After collecting the throttle opening and surge tank internal pressure, the mobile terminal 100 collects abnormal noise (step S2). For example, when an operator presses the engine switch of the vehicle 300, the internal combustion engine 2 starts operating. When the internal combustion engine 2 starts operating, the operator operates the mobile terminal 100 to activate the microphone for a certain period of time. As a result, the mobile terminal 100 collects abnormal noise for a certain period of time as time-series data via the microphone.

[0026] Once the abnormal sound has been collected, the mobile terminal 100 performs frequency analysis (step S3). Specifically, the mobile terminal 100 performs FFT (Fast Fourier Transform). This identifies the frequency components of the abnormal sound collected by the mobile terminal 100. Once the frequency analysis is complete, the mobile terminal 100 displays a data details screen, as shown in FIG. 3(a).

[0027] The data details screen includes an all playback button BT1, an abnormal noise range designation button BT2, a first coordinate that displays time-series data related to the throttle opening, and a second coordinate that displays time-series data related to the surge tank internal pressure. A predetermined graph representing the time-series data is displayed on the first coordinate, and this graph appears on the first coordinate when an information acquisition button BT3 (described later) is pressed. The second coordinate is similar to the first coordinate. When the all playback button BT1 is pressed by the operator, the mobile terminal 100 plays back the collected abnormal noises.

[0028] When the worker presses the abnormal sound range designation button BT2, the mobile terminal 100 displays an abnormal sound range designation screen as shown in FIG. 3(b). The abnormal sound range designation screen includes an area 101 that displays the spectrogram of the abnormal sound, an information acquisition button BT3, an all playback button BT4, and a range playback button BT5. A spectrogram is a graph that performs frequency analysis continuously over time and displays sound intensity using color, thereby displaying intensity, frequency components, and time in three dimensions. A two-dimensional contour diagram that identifies the intensity and frequency components of the abnormal sound contained in the spectrogram of the abnormal sound may also be displayed in area 101.

[0029] When the abnormal sound range designation screen is displayed, the mobile terminal 100 selects the abnormal sound generation range (step S4). Specifically, as shown in FIG. 3(b), the worker can designate the desired abnormal sound range by tracing part of the area 101 in a straight line with their finger. When the mobile terminal 100 detects the designation of the abnormal sound range, it selects the designated abnormal sound generation range. When the worker presses the play within range button BT5, the mobile terminal 100 plays back the abnormal sound within the selected abnormal sound generation range. This allows the worker to listen carefully to the abnormal sound within the selected abnormal sound generation range.

[0030] Once the abnormal noise occurrence range is selected, the mobile terminal 100 acquires the throttle opening and surge tank pressure within the range (step S5). Because the mobile terminal 100 has collected the throttle opening and surge tank pressure in advance through the processing of step S1, it can acquire the throttle opening and surge tank pressure within the range based on the time-series information corresponding to the abnormal noise occurrence range. Once the throttle opening and surge tank pressure within the range have been acquired, the mobile terminal 100 transmits the acquired throttle opening and surge tank pressure to the server device 200 as time-series data. As a result, the server device 200 receives the throttle opening and surge tank pressure as time-series data.

[0031] When the server device 200 receives the throttle opening and surge tank internal pressure, it determines whether a predetermined occurrence condition is met (step S6). The predetermined occurrence condition is a condition under which a specific abnormal noise occurs when the electric throttle 26 is suddenly opened. As shown in FIG. 4(a), the server device 200 has an abnormal noise judgment map that includes an area 201 that indicates the inside of the specific abnormal noise occurrence range and an area 202 that indicates outside of the specific abnormal noise occurrence range.

[0032] Here, region 201 can be represented by a range equal to or greater than a first threshold and equal to or less than a second threshold. The first threshold is, for example, 21°, 22°, 23°, etc., and the second threshold is, for example, 54 kPa (kilopascals), 55 kPa, 56 kPa, etc. Region 202 can be represented by a range smaller than the first threshold and larger than the second threshold. Note that region 201 is not limited to a rectangle, and may be a polygon, as shown in FIG. 4(a), or a combination of a polygon and an ellipse.

[0033] Because the throttle opening and surge tank internal pressure received by the server device 200 are time-series data, the throttle opening and surge tank internal pressure can be represented in the abnormal sound judgment map by state transition graph G. If graph G is included in region 201, the server device 200 determines that a predetermined occurrence condition is satisfied (step S6: YES). If the server device 200 determines that the predetermined occurrence condition is satisfied, it determines that the collected abnormal sounds (specifically, abnormal sounds within a specified range) include a specific abnormal sound whose main component is a frequency component Fz within a range of several kilohertz, for example, a range of 2 kHz (kilohertz) to 6 kHz, as shown in FIG. 4(b) (step S7).

[0034] In this case, the server device 200 executes a setting to display the specific abnormal sound preferentially over other abnormal sounds described below (step S8). The server device 200 may execute the setting to display the specific abnormal sound preferentially after calculating the probability that the collected abnormal sound is the specific abnormal sound, or the probability that the collected abnormal sounds contain the specific abnormal sound. In addition, the server device 200 may calculate the probability that the collected abnormal sound is another abnormal sound, or the probability that the collected abnormal sounds contain another abnormal sound.

[0035] On the other hand, if graph G is included in region 202, server device 200 determines that the predetermined occurrence condition is not satisfied (step S6: NO). If it is determined that the predetermined occurrence condition is not satisfied, it determines that another abnormal noise is included in the collected abnormal noise (step S9). Examples of another abnormal noise include airflow noise other than the specific abnormal noise, as well as gear noise and shift change noise.

[0036] Instead of the abnormal sound judgment map, the server device 200 may include a trained model that has been machine-learned in advance using the throttle opening and surge tank pressure as training data and a specific abnormal sound or several other types of abnormal sounds as correct answer data. The server device 200 may calculate or identify the probability that a specific abnormal sound or a different abnormal sound using the throttle opening, surge tank pressure, and trained model. The server device 200 may also use both the abnormal sound judgment map and the trained model to improve the accuracy of calculating or identifying the probability that a specific abnormal sound or a different abnormal sound is present. Furthermore, when the server device 200 receives new throttle opening and surge tank pressure, it may perform re-learning using the new throttle opening and surge tank pressure as training data, thereby deforming the shape of the region 201.

[0037] When the processing of step S8 or step S9 is completed, the mobile terminal 100 displays the abnormal sound candidates and ends the processing (step S10). For example, when the processing of step S8 is completed, the server device 200 transmits display data to the mobile terminal 100 that displays a specific abnormal sound in priority over other abnormal sounds. As a result, the mobile terminal 100 receives the display data and, based on the display data, displays the specific abnormal sound in priority over other abnormal sounds, as shown in FIG.

[0038] By checking the screen display of the mobile terminal 100, the worker can understand the type of abnormal noise, which can reduce the number of incorrect parts replaced. For example, by checking the screen that displays a specific abnormal noise preferentially, the worker can understand that the cause of the abnormal noise is the sudden opening of the electric throttle 26, which can lead to the appropriate part replacement.

[0039] As described above, the abnormal sound detection system ST for an internal combustion engine 2 according to this embodiment detects abnormal sounds generated in the internal combustion engine 2, which includes the electric throttle 26 and the surge tank 24. The abnormal sound detection system ST includes a mobile terminal 100 and a server device 200 as processing devices. The mobile terminal 100 collects abnormal sounds via a microphone, and if the abnormal sound contains a frequency component mainly in the range of several kilohertz, it acquires the throttle opening of the electric throttle 26 and the surge tank pressure of the surge tank 24. If the throttle opening and the surge tank pressure satisfy the conditions for a specific abnormal sound generated due to the sudden opening of the electric throttle 26, the server device 200 determines that the collected abnormal sounds include the specific abnormal sound. This makes it possible to identify the specific abnormal sound generated due to the sudden opening of the electric throttle 26 from multiple types of abnormal sounds.

[0040] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as described in the claims.

[0041] For example, the mobile terminal 100 may be provided with the functions of the server device 200. This allows the mobile terminal 100 to identify the specific abnormal noise by itself. [Explanation of symbols]

[0042] ST Internal combustion engine noise detection system 2. Internal combustion engine 24 Surge Tank 26 Electric Throttle 40 Engine ECU 100 mobile devices 200 Server device 300 vehicles

Claims

1. An abnormal noise detection system for an internal combustion engine that detects abnormal noise generated in an internal combustion engine including a throttle and a surge tank, The processing device included in the abnormal sound detection system includes: Collecting the throttle opening and the internal pressure of the surge tank; Collecting the abnormal sound via a microphone; From the collected opening degrees and internal pressures, the opening degrees and internal pressures within a range designated and selected from a diagram showing the intensity of the abnormal noise are obtained; If the acquired opening degree and internal pressure satisfy a condition for the occurrence of a specific abnormal noise that occurs when the throttle is suddenly opened and that contains a frequency component in the range of 2 kHz to 6 kHz as a main component, it is determined that the specific abnormal noise is included in the abnormal noise. An abnormal noise detection system for an internal combustion engine.

2. When the opening degree and the internal pressure do not satisfy the occurrence condition, the processing device determines that the abnormal noise includes another abnormal noise different from the specific abnormal noise.

2. The system for detecting abnormal noise in an internal combustion engine according to claim 1.

3. the processing device displays the specific abnormal noise in priority to the other abnormal noises.

3. The system for detecting abnormal noise in an internal combustion engine according to claim 2.

4. The processing device determines that the occurrence condition is satisfied when the opening degree is equal to or greater than a first threshold value and the internal pressure is equal to or less than a second threshold value.

3. The system for detecting abnormal noise in an internal combustion engine according to claim 1 or 2.

5. the processing device includes a first processing device provided in the mobile terminal and a second processing device provided in the server device; the first processing device collects the abnormal noise and acquires the opening degree and the internal pressure; the second processing device determines that the abnormal noise includes the specific abnormal noise; 3. The system for detecting abnormal noise in an internal combustion engine according to claim 1 or 2.

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