JP2000123267A - Device for approaching vehicle detection and method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an approaching vehicle detection device and its detection method which can judge whether or not there is an approaching vehicle by comparing a form of a sound pressure level signal in a specified frequency band of vehicle sound information which is inputted in advance with a sound pressure level signal form in a specified frequency band of collected surrounding sounds at the time of judging the existence/nonexistence of an approaching vehicle. SOLUTION: This device is composed of a sound collection part which is installed to its own vehicle V and collects surrounding sounds, a signal processing part E for converting the surrounding sounds into a sound pressure level signal, a comparison judgement part J which judges existence/nonexistence of an approaching vehicle by comparing a waveform in a specified frequency band of the sound pressure level signal with a waveform in a specified frequency band of the sound pressure level of a general vehicle stored in a vehicle information part R, and a display part D for displaying a judgement result of the comparison judgement part J.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an approaching vehicle detection device that detects an approaching vehicle around a vehicle by analyzing the surrounding sound and determines whether or not the approaching vehicle exists, and more particularly to a sound of an ambient sound in a specific frequency band. The present invention relates to an approaching vehicle detection device that determines the presence or absence of an approaching vehicle by comparing the waveform shape of the pressure level signal with the waveform shape of the sound pressure level signal of the own vehicle, and a detection method thereof.

[0002]

2. Description of the Related Art In a case where a building or the like becomes an obstacle in the driver's field of view and makes a vehicle approach an intersection where a left or right view is not available and a traffic light is not installed, the driver temporarily stops himself immediately before the intersection. Stop the vehicle and check the safety in the left and right direction. Then, when it is not possible to confirm the safety in the left and right direction from that position, the vehicle will be gradually advanced to a position where it is easy to see and the confirmation will be performed, but at this time, the leading end of the vehicle has already entered the intersection In some cases, there is a high risk of causing a collision accident with a vehicle approaching from the left and right directions. In order to prevent such a contact accident, voice recognition technology is used to detect surrounding sounds such as the running sound of an approaching vehicle approaching the vehicle, and to visually confirm the driver's own approaching approaching vehicle. An approaching vehicle detection device and a detection method for providing information on presence / absence of a driver to a driver are disclosed in Japanese Utility Model Laid-Open No. 6-110.
No. 99, for example.

[0003] In such an approaching vehicle detection device and its detection method, two microphones having directivity are attached to the left and right sides of the own vehicle, respectively, and external sound information collected from each microphone is collected. The sound signal is converted into an electroacoustic signal, and the converted electroacoustic signal is converted into a sound pressure level signal, which is then input to a speech recognition device, and the presence or absence of an approaching vehicle is detected at regular intervals for a predetermined time.

[0004]

By the way, when ambient sound is collected by such an approaching vehicle detection device and its detection method, the sound of the own vehicle and the sound of the approaching vehicle are collected, and other sounds are also collected. Collecting ambient sounds such as pile driving noise at construction sites, siren noise of emergency vehicles,
Therefore, various types of sound information are mixed. When sound information having a large sound pressure level is mixed in the sound information, the sound quality determination is not performed by these devices, and therefore, depending on the situation, erroneous information may be provided to the driver.

Therefore, an approaching vehicle detection apparatus and method for detecting the approaching vehicle according to the present invention have been made in view of these problems. By comparing the waveform shape of the sound pressure level signal in the specific frequency band of the general vehicle sound information obtained and the waveform shape of the sound pressure level signal in the specific frequency band of the collected ambient sound, the presence or absence of an approaching vehicle is determined. It is an object of the present invention to provide an approaching vehicle detection device and a detection method thereof that can determine the approaching vehicle.

[0006]

In order to solve the above-mentioned problems, an approaching vehicle detecting device according to the present invention comprises a sound collecting unit mounted on the host vehicle for collecting ambient sounds, and a sound pressure level for the ambient sounds. A signal processing unit that converts the signal into a signal, by comparing the waveform shape of the specific frequency band of the specific frequency band of the sound pressure level signal and the waveform shape of the specific frequency band of the general vehicle sound pressure level signal stored in the vehicle information unit, A means for solving the problem has a configuration having a comparison / judgment unit for judging the presence / absence of an approaching vehicle and a display unit for displaying the judgment result of the comparison / judgment unit.

The approaching vehicle detection method includes a sound collecting step attached to the own vehicle for collecting ambient sound, a signal processing step for converting the ambient sound into a sound pressure level signal, By comparing the waveform shape of the specific frequency band with the waveform shape of the specific frequency band of the sound pressure level signal of a general vehicle stored in the vehicle information process, a comparison determining step of determining whether there is an approaching vehicle, A detection method including a display step of displaying a determination result of the comparison determination step is a means for solving the problem.

[0008] With such an approaching vehicle detection device and its detection method, the presence or absence of an approaching vehicle can be accurately determined.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an apparatus for detecting an approaching vehicle according to the present invention.

[0010] The approaching vehicle detection device 1 according to the present embodiment.
Is a sound collection unit M attached to the vehicle V as shown in FIG.
(M1, M2) and ECU (Electronic Control Un
It) is generally constituted by a control unit K corresponding to it) and a display unit D for displaying and outputting information. The signal processing unit E
Is a left signal processing unit E1 and a right signal processing unit E that respectively process ambient sounds collected by the left sound collection unit M1 and the right sound collection unit M2.
2, and the control unit K includes a left signal processing unit E
1 and a vehicle detection unit T that detects an approaching vehicle V1 from the sound pressure level signal from the right signal processing unit E2, a vehicle information unit R that stores sound pressure level signal information of a general vehicle, and a vehicle information unit R. A comparison judging unit J for judging the presence or absence of the approaching vehicle V1 based on the vehicle sound information; and an information control unit C for controlling the detection result of the vehicle detecting unit T and the provision of the judgment result of the comparison judging unit J to the display unit. It consists of.

Each part constituting the approaching vehicle detection device 1 will be described in detail. Left sound collecting section M1 and right sound collecting section M2
Is a part that collects ambient sounds of the own vehicle V,
And a right sound collecting unit M2 mounted on the right side surface. Microphones having directivity are used for the left sound collecting section M1 and the right sound collecting section M2, and their mounting positions are on the left and right side surfaces of the host vehicle V, respectively. In the present embodiment, it is incorporated and attached to a door mirror. In addition, by incorporating it into the door mirror, the appearance of the vehicle V is not impaired, and
Strength and other attachment properties can be improved. Note that the installation position is not limited to the door mirror, but may be a position that does not impair the appearance of the vehicle V, for example, a door mirror peripheral portion, a direction indicator unit, a door handle unit, a protection molding unit, or the like.

The left sound collecting section M1 and the right sound collecting section M2 collect ambient sounds of the vehicle V and convert an acoustic signal corresponding to the ambient sounds into an electric acoustic signal. In particular,
As shown in the graphs G1 and G2 of FIG. 5, the electroacoustic signal 14 with the horizontal axis representing time (seconds) and the vertical axis representing voltage (volts)
a and 14b. Since the sound signal before conversion into the electric sound signal is a signal containing sound information of the entire frequency band in the surrounding sound, the voltage values of the electric sound signals 14a and 14b also increase as the surrounding sound increases, as shown in FIG. It increases as shown in the graphs G1 and G2. In addition, in the graphs G1 and G2 of FIG. 5, the electroacoustic signal on the left side of the vehicle V is indicated by reference numeral 14a, and the electroacoustic signal on the right side is indicated by reference numeral 14.
Indicated by b. The electroacoustic signal 1 thus converted
4a and 14b are sent to a left signal processing unit E1 and a right signal processing unit E2, respectively, which will be described later.

Next, the signal processing section E will be described. The signal processing unit E includes the left sound collection unit M1 and the right sound collection unit M as described above.
Left signal processing unit E for processing each of the ambient sounds collected in step 2
1 and a right signal processing unit E2. The left signal processing unit E1 and the right signal processing unit E2 perform processing to be described later on the electroacoustic signals from the left and right left sound collection units M1 and M2, respectively, and have the same configuration and operation. belongs to. Therefore, unless it is necessary to explain in the future,
The left signal processing unit E1 and the right signal processing unit E2 will be described simply as the signal processing unit E.

The signal processing unit E first processes the low frequency band and high frequency band frequency components from the electroacoustic signals 14a and 14b converted by the left sound collecting unit M1 and the right sound collecting unit M2 by the band-pass filter. And a process of converting it into a corrected electroacoustic signal is performed. This conversion process removes so-called high-frequency and low-frequency noise components that are not directly related to the running sound of the vehicle.

Next, the corrected acoustic signal is Fourier-transformed by a fast Fourier transform (FFT) unit every predetermined time (for example, every 0.1 second), and is converted into a sound pressure level signal at each time. The Fourier transform is performed because the corrected sound signal is a signal representing a temporal change, and a signal represented by a function in a frequency space is suitable for analyzing a traveling sound of an approaching vehicle. The graph G3 in FIG. 5 shows a state in which the corrected acoustic signal is Fourier-transformed and converted into a sound pressure level signal, and the horizontal axis of the graph G3 indicates the frequency (H
z) and the vertical axis indicates the reference intensity (2 × 10 −4 dyn / cm).
As a ratio (dB) to 2), the sound pressure level signal 15 at a certain time is extracted and shown. The sound pressure level signal 15 exists for each predetermined time.

When the processing by the signal processing unit E is completed, the result of this processing is sent to the control unit K for further processing. The control unit K stores a vehicle detection unit T that detects an approaching vehicle from the sound pressure level signals processed by the left signal processing unit E1 and the right signal processing unit E2 as described above, and stores a sound pressure level signal of a general vehicle. A vehicle information unit R, a comparison / judgment unit J for judging the presence / absence of an approaching vehicle based on vehicle sound information from the vehicle information unit R, and a display unit of the detection result of the vehicle detection unit T and the judgment result of the comparison judgment unit J And an information control unit C for controlling the provision of the information.

The vehicle detecting section T detects an approaching vehicle by comparing the absolute amount of the sound pressure level signal converted by the signal processing section E in a specific frequency band with a judgment level. Here, the absolute amount of the sound pressure level signal means the value of the vertical axis at each time of the sound pressure level signal on the time axis shown in the graph G4 of FIG. 5, and the judgment level is the graph G5 of FIG. The reference of the sound pressure level estimated as the traveling sound emitted by the approaching vehicle shown in FIG.

The specific frequency band of the sound pressure level signal is selected for the following reason. In general, in the case of noise due to vibration generated from the structure of a vehicle, sound waves of about 1 kHz are standing near the tire contact due to resonance of a sound field. It is clear that this value is specific to the tire and does not fluctuate due to a change in vehicle speed or the like. Accordingly, the frequency band of about 1 kHz is selected as the specific frequency band. By this selection, erroneous determination due to so-called noise generated from things other than the vehicle can be effectively prevented.

Hereinafter, a specific detection process of the vehicle detection unit T will be described with reference to FIG. First, a graph G3 in FIG.
And a process of calculating the average of the sound pressure level signals of the specific frequency band at each time while extracting the specific frequency band 15a around 1 kHz shown in FIG. This processing is executed at predetermined time intervals, and conversion into a sound pressure level signal on the time axis is performed.

A graph G4 in FIG. 5 shows the absolute amounts of the sound pressure level signals 16a and 16b with respect to the left and right time axes, respectively.
The horizontal axis is time (seconds), and the vertical axis is reference intensity (2 × 10
−4 dyn / cm 2). The absolute value of the sound pressure level signal corresponds to the value on the vertical axis of the sound pressure level signals 16a and 16b with respect to the time axis.

The lower limit 17 is set for the sound pressure level signals 16a and 16b on the time axis in the graph G4 in FIG. 5, but the lower limit 17 is set for the sound pressure level signals 16a and 16b on the time axis. In the following cases, the sound pressure level signals 16a and 16b are corrected to the lower limit value 17. By correcting the lower limit, the occurrence of erroneous detection due to noise is reduced, and the accuracy of the vehicle approach determination based on the sound pressure level signals 18a and 18b (see graph G5) with respect to the time axis described later is improved. Can be done.

By such processing, the absolute values of the sound pressure level signals 18a and 18b for each of the left and right time axes are compared with the judgment level 19, and when the absolute amount exceeds the judgment level 19, the approaching vehicle Is detected, while if not exceeded, it is determined that the approaching vehicle is not detected. In the graph G5, the sound pressure level signals 18a and 18b with respect to the time axis are expressed as time (seconds) on the horizontal axis, and the vertical axis is expressed as a ratio (dB) to the reference intensity (2 × 10 −4 dyn / cm 2). .

Next, the vehicle information section R will be described.
The vehicle information section R is a part that stores sound pressure level signal information of a general vehicle. The stored sound pressure level signal information of the vehicle includes an engine that is a device that emits sound in a general vehicle, a running sound from tires, and auxiliary equipment other than the engine. Note that the sound pressure level signal information means the waveform shape of the sound pressure level signal with respect to the frequency axis. Auxiliary equipment refers to the engine,
A general term for equipment mounted on a vehicle that plays an auxiliary role, such as a compressor, a power steering pump, an alternator, and a radiator fan.

Next, the comparison judgment section J will be described. In the comparison judgment unit J, the vehicle sound information (the waveform shape of the sound pressure level signal in the specific frequency band) from the vehicle information unit R is used to compare the waveform with the sound pressure level signal of the surrounding sound in the specific frequency band. It is determined whether the vehicle V1 exists.

First, the sound pressure level signal 15 of the ambient sound converted by the signal processing unit E is sent to the comparison judgment unit J. Then, of the vehicle sound information stored in the vehicle information section R, the sound pressure level signal of the general running sound of the vehicle is also sent to the comparison determination section J. Then, as shown in the graph G6 of FIG. 6, after the sound pressure level signal 15 of the ambient sound and the vehicle sound information of the general vehicle, particularly the sound pressure level signal of the traveling sound, are selected, they are superimposed to form a specific frequency band ( (Specific frequency band around 1kHz)
A comparison is made between the waveform shapes of the two sound pressure level signals at 15a.

The comparison between the waveform shapes of the two sound pressure level signals of the signal processing unit E and the vehicle information unit R in the specific frequency band 15a is performed by analyzing the difference between the waveform shapes of the two sound pressure level signals. Is within the range value, the presence or absence of the approaching vehicle is determined to be "there is an approaching vehicle." On the other hand, when the analysis value is out of the predetermined range value, it is determined that “there is no vehicle approaching”.

Next, the information control unit C controls whether or not to provide the detection result provided by the vehicle detection unit T and the judgment result of the comparison judgment unit J to a display unit D described later. By providing information on the presence or absence of the approaching vehicle V1 to the display unit D based on the detection result from the vehicle detection unit T and the determination result of the comparison determination unit J, more accurate information can be provided. The display unit D displays information on the approaching vehicle V1 from the information control unit C.

An approaching vehicle detection device 1 having such a configuration
The following describes a method for detecting an approaching vehicle by using the following method. As shown in FIG. 3, the approaching vehicle detection method according to the present invention includes a sound collecting step (S
10), a signal processing step (S20), a vehicle detection step (S30), a comparison determination step (S40), a vehicle information step (S50), an information control step (S60), and a display step (S70). It is configured. The signal processing step (S20) includes a left signal processing step (S20L) and a right signal processing step (S20) for processing the ambient sounds collected in the left sound collection step (S10L) and the right sound collection step (S10R), respectively.
20R).

The sound collecting step (S10) will be described. The right sound collecting step (S10R) and the left sound collecting step (S10) are described.
Since L) has the same process, only the right sound collecting process (S10R) will be described, and the left sound collecting process (S10R) will be described.
The description of L) is omitted. The right sound collection step (S10R)
This is a step of collecting ambient sounds of the own vehicle V. In this step, ambient sounds of the own vehicle V are collected by a directional microphone attached to the left side surface of the own vehicle V.

In the right sound collecting step (S10R), as shown in FIG. 4, the surrounding sound of the vehicle V is collected, and an acoustic signal corresponding to the surrounding sound is converted into an electric acoustic signal (S11). The collected sound signal is represented by a graph G in FIG.
1, as shown by G2, the horizontal axis represents time (seconds) and the vertical axis represents voltage (volts), and is converted into electroacoustic signals 14a and 14b. Since the sound signal before conversion into the electric sound signal is a signal including sound information of the entire frequency band in the surrounding sound, the voltage values of the electric sound signals 14a and 14b also increase as the surrounding sound increases, as shown in FIG. It increases as shown in the graphs G1 and G2. The thus converted electroacoustic signals 14a and 14b are used in a left signal processing step (S20) to be described later.
L) and the right signal processing step (S20R).

The left signal processing step (S20L) and the right signal processing step (S20) of the signal processing step (S20) shown in FIG.
R) is, first, the electroacoustic signal 1 converted in the sound collection step (S10) by the band-pass filter as shown in FIG.
The processing of removing the frequency components of the low frequency band and the high frequency band from 4a and 14b and converting them into corrected sound signals is performed (S21). By this conversion processing, so-called high-frequency and low-frequency noise components which are not directly related to the running sound of the vehicle are removed.

Next, the corrected acoustic signal is Fourier-transformed by a fast Fourier transform (FFT) unit at predetermined time intervals (for example, every 0.1 second), and is converted into a sound pressure level signal at each time (S22). ). The Fourier transform is performed because the corrected sound signal is a signal representing a temporal change, and a signal represented by a function in a frequency space is suitable for analyzing the traveling sound of the approaching vehicle V1. Graph G in FIG.
3 shows a state in which the corrected acoustic signal is Fourier-transformed and converted into a sound pressure level signal. The horizontal axis of the graph G3 represents the frequency (Hz), and the vertical axis represents the reference intensity (2 × 10
The sound pressure level signal 15 at a certain time is extracted and expressed as a ratio (dB) to (−4 dyn / cm 2). The sound pressure level signal 15 exists for each predetermined time.

When the Fourier transform (FFT) is completed, a flag is initialized as shown in FIG. 4 (S23).
Then, as initialization of the flags, the “vehicle likeness flag” is set to “1”, and the “approaching vehicle presence flag” and the “approaching vehicle absence flag” are set to “OFF”. Here, "flag" means the occurrence of a condition in the information determination step, and "initialization of the flag" means the initial state of various identifiers used to notify the occurrence of the condition in the information determination step. Means

The sound pressure level signal processed in the signal processing step (S20) is applied to the vehicle detection step (S3) as shown in FIG.
0) and sent to the comparison / determination step (S40).

In the comparing and judging step (S40), the sound pressure level signal processed in the signal processing step (S20) and the sound pressure which is vehicle sound information of a general vehicle stored in a vehicle information step (S50) described later. The waveform shape is compared with the level signal to determine whether there is an approaching vehicle. First, it is determined whether or not the sound pressure level signal sent from the signal processing step (S20) has a constant sound pressure level (S41). If the sound pressure level is equal to or higher than the predetermined sound pressure level, the sound pressure level signal of the vehicle sound information of a general vehicle stored in the vehicle information step (S50) and the sound pressure level signal processed in the signal processing step (S20) The comparative analysis of the waveform shape in the specific frequency band is performed (S42, S43).

In this step (S43), as shown in FIG. 6, for example, the difference between the specific frequency bands of the two sound pressure level signals is measured, and the difference between the two sound pressure level signals is measured. If it is within the set range, it is analyzed as "similar", and if it is out of the set range, it is analyzed as "not similar" (S43). If the result of this analysis is "not similar", the "vehicle likeness flag" is set to "0" (S44). On the other hand, when it is analyzed that "similar", the "vehicle likeness flag" is maintained at "1" (S44).

The vehicle detecting step (S30) receives the sound pressure level signal processed in the signal processing step (S20),
This is a step of comparing the absolute amount of the sound pressure level signal in the specific frequency band with the judgment level to detect the approaching vehicle V1. First, upon receiving the sound pressure level signal processed in the signal processing step (S20), a specific frequency band of the sound pressure level signal is selected (S31). As described above, the specific frequency band includes, for example, noise due to vibration generated from the structure of the vehicle, such as one near the tire contact due to resonance of the sound field.
Although a sound wave of about kHz is present, it is clear that this value is unique to the tire and does not fluctuate due to a change in vehicle speed or the like.
The frequency band around z is selected (S3
1).

Then, the sound pressure level of the sound pressure level signal is measured. If the sound pressure level signal does not reach a certain value, the sound pressure level signal is corrected for a lower limit value. Is raised (S32). The correction of the lower limit refers to correction to the lower limit 17 set for the sound pressure level signals 16a and 16b with respect to the time axis, as shown in a graph G4 of FIG. By correcting the lower limit, the occurrence of erroneous detection due to noise can be reduced, and the accuracy of vehicle approach determination based on sound pressure level signals 18a and 18b (see graph G5) described later can be improved. .

Next, a comparison is made between the absolute amount of the sound pressure level signal in which the correction of the lower limit has been completed in the specific frequency band and the judgment level (S33). If the sound pressure level signal has a value equal to or higher than the determination level in this step (S33), it is determined that the approaching vehicle V1 has been detected (S34). on the other hand,
If the sound pressure level signal is lower than the determination level, it is determined that there is no approaching vehicle (S35). The results of these two determinations are sent to the information control step (S60) described later, and it is determined whether or not the approaching vehicle V1 exists (S62). Note that the absolute amount of the sound pressure level signal refers to the value of the vertical axis at each time of the sound pressure level signal on the time axis shown in the graph G4 of FIG. This refers to the reference of the sound pressure level estimated as the traveling sound generated by the approaching vehicle shown.

The detection result of the vehicle detection step (S30) and the judgment result of the comparison judgment step (S40) are both sent to the information control step (S60). In this information control step (S60), the presence or absence of an approaching vehicle is determined based on the detection result of the vehicle detection step (S30). That is, "vehicle-likeness flag"
If (S44) is "0", it is determined that there is an approaching vehicle (S61), and the "approaching vehicle presence flag" is turned ON (S63). In addition, "vehicle likeness flag" (S4
If 4) is "1", it is determined that there is no approaching vehicle (S6).
1) The "no approaching vehicle flag" is turned ON (S6)
4).

The judgment result sent from the comparison judging step (S40) is based on the judgment of "approaching vehicle" (S34) and "no approaching vehicle" (S35) to judge the presence or absence of the approaching vehicle V1 (S62). ). That is, "there is an approaching vehicle" (S3
If “4) is ON, the“ approaching vehicle present flag ”is in the ON state (S63), and if“ No approaching vehicle ”(S35) is ON, the“ approaching vehicle absence flag ” Is turned ON (S64).

When the presence or absence of an approaching vehicle is detected and determined by the above-described steps, the determination result is sent to a display step (S70), and the presence or absence of the approaching vehicle is displayed to the driver. .

In the description of the present embodiment, the vehicle detecting section (vehicle detecting step) includes a portion (step) for detecting approaching vehicle V1, and the information controlling section (information controlling step) further includes an approaching vehicle. However, it is needless to say that the presence or absence of the approaching vehicle can be determined only by the comparison determination unit (comparison determination step).

[0044]

According to the approaching vehicle detection device and the detection method thereof according to the present invention, the following effects can be obtained. That is, when determining the presence or absence of the approaching vehicle, the waveform shape of the sound pressure level signal in the specific frequency band of the traveling sound of the vehicle information input in advance and the sound pressure level signal in the specific frequency band of the collected ambient sound are used. The comparison analysis with the waveform shape determines the presence or absence of an approaching vehicle.This is a so-called sound quality determination, so it is possible to determine the presence or absence of an approaching vehicle more accurately than in the past. Become.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of an intersection with a blind spot.

FIG. 2 is a plan view of a host vehicle equipped with the approaching vehicle detection device according to the present invention.

FIG. 3 is a system configuration diagram of an approaching vehicle detection method according to the present invention.

FIG. 4 is an overall flowchart of an approaching vehicle detection method.

FIG. 5 is a conceptual diagram of an approaching vehicle detection method.

FIG. 6 is a comparison diagram of sound pressure level signals in a specific frequency band.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 approaching vehicle detection device C information control unit D display unit E signal processing unit J comparison determination unit K control unit M1 left sound collection unit M2 right sound collection unit R vehicle information unit T vehicle detection unit V own vehicle V1 approaching vehicle

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Takayuki Tsuji 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. 5C086 AA53 BA22 CA09 CB26 EA11 EA15 EA33 EA45 FA11 5H180 AA01 CC11 LL01 LL02 LL04 LL08 LL15 5J070 AC01 AE01 AF03 AH25 AH35 AH40 AK22 BD10 BG01

Claims (2)

[Claims] 1. A sound collection unit attached to a host vehicle for collecting ambient sound, a signal processing unit for converting the ambient sound into a sound pressure level signal, and a waveform shape of the sound pressure level signal in a specific frequency band. By comparing the sound pressure level signal of a general vehicle stored in the vehicle information unit with the waveform shape of a specific frequency band, a comparison determination unit that determines whether there is an approaching vehicle, and a determination result of the comparison determination unit An approaching vehicle detection device, comprising: a display unit for displaying. 2. A sound collecting step mounted on the vehicle to collect ambient sound, a signal processing step of converting the ambient sound into a sound pressure level signal, and a waveform shape of the sound pressure level signal in a specific frequency band. By comparing the sound pressure level signal of a general vehicle stored in the vehicle information process with the waveform shape of a specific frequency band, a comparison determining step of determining the presence or absence of an approaching vehicle, and a determination result of the comparison determining step And a display step of displaying.