JP2012184958A - Vehicle vibration detection method and vehicle vibration detection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect vibration transferred from a vibrating vehicle to an occupant using a signal acquirable from the occupant.SOLUTION: A vehicle vibration detection apparatus 1 has an evaluation device body 10 and a signal acquisition unit 20. The signal acquisition unit 20 acquires an electric signal from electrodes disposed on the occipital regions O3 and O4 of an occupant 3 on the basis of international laws 10-20. The evaluation device body 10 includes a signal input section 11 to which the electric signal acquired in the signal acquisition unit 20 is inputted, an analysis section 12 which analyzes the electric signal supplied to the signal input section 11, and a display section 13 which displays a result of analyzing the electric signal by the analysis section 12. The analysis section 12 specifies a vibration frequency on the basis of a factor load and an expression indicating a border line.

Description

  The present invention relates to a vehicle vibration detection method and a vehicle vibration detection device for evaluating vibration transmitted to an occupant when the vehicle travels using a signal that can be acquired from the occupant.

  2. Description of the Related Art Conventionally, methods for detecting vibrations in a vehicle have been disclosed in the development of products for vehicles such as automobiles, motorcycles, and trains. (For example, patent document 1). In the technique disclosed in Patent Document 1, a vibration detection device is installed in a vehicle to detect vehicle vibration.

JP 2003-299203 A

  According to Patent Document 1, the vibration of the vehicle can be detected. However, since the feeling of “vibration” varies depending on the occupant, the vibration transmitted from the vehicle to the occupant affects the evaluation of the “riding comfort” felt by the occupant rather than the direct vibration of the vehicle. it is conceivable that.

  Therefore, an object of the present invention is to provide a vehicle vibration detection method and a vehicle vibration detection device that can detect a frequency transmitted from a vibrating vehicle to an occupant using a signal that can be acquired from the occupant.

  Based on the prediction that the brain waves that reflect brain activity associated with human emotional changes can be used to detect vehicle vibrations, the applicant has determined that the electrodes placed on the human head As a result, it has been found that a specific frequency band component extracted from an electrical signal obtained from the vehicle is affected by the vibration of the vehicle.

  The present invention is to detect vibration transmitted from a vehicle to an occupant using a signal that can be acquired from the occupant.

  A feature of the present invention is a vehicle vibration detection method for detecting a frequency transmitted from a vehicle to an occupant using a signal that can be acquired from the occupant. The vehicle vibration detection method is based on the international method 10-20 at a plurality of locations on the occupant's head. A signal acquisition step of acquiring an electrical signal from the electrodes arranged in a row, an analysis step of executing a signal analysis for extracting a spectrum of a frequency band component affected by the vibration frequency of the vehicle from the acquired electrical signal, and a vibration Based on the electrical signal obtained from the electrode placed on the head of the subject based on the international method 10-20, the reference associated with the frequency of the vibration, and the extracted spectrum And a specific step of specifying the frequency.

  According to the features of the present invention, the frequency of a vehicle transmitted from a vibrating vehicle to the vehicle occupant can be detected from a spectrum extracted from an electrical signal acquired from the head of the vehicle occupant. That is, it is possible to detect the vehicle vibration frequency felt by the occupant.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle vibration detection method and vehicle vibration detection apparatus which can detect the frequency transmitted to a passenger | crew from the vibrating vehicle using the signal acquirable from a passenger | crew can be provided.

FIG. 1 is a schematic diagram illustrating a vehicle vibration detection device. FIG. 2 is a configuration diagram illustrating the vehicle vibration detection device. FIG. 3 is a flowchart for explaining a detection method for detecting the vibration frequency of the vehicle. FIG. 4 is a flowchart for explaining a detection method for detecting the frequency of the vehicle according to the modification. FIG. 5 is a schematic diagram for explaining a test apparatus for detecting vehicle vibration performed using the vehicle vibration detection apparatus. FIG. 6 is a diagram showing the result of a significant difference test. FIG. 7 is a diagram illustrating a relationship between a measurement location and a classification rate at the measurement location.

  Next, a vehicle vibration detection method and a vehicle vibration detection device according to the present invention will be described with reference to the drawings. Specifically, (1) configuration of vehicle vibration detection device, (2) description of evaluation method, (3) action / effect, (4) test for identifying frequency component that can be an index, (5), other implementations A form is demonstrated.

(1) Configuration of Vehicle Vibration Detection Device The vehicle vibration detection device 1 will be described with reference to FIG. Specifically, (1-1) a test for detecting vehicle vibration, (1-2) a configuration of the vehicle vibration detection device, and (1-3) derivation of a mathematical expression indicating a boundary line will be described.

(1-1) Test for Detecting Vehicle Vibration FIG. 1 is a diagram illustrating a vehicle vibration detection device 1. The vehicle vibration detection device 1 includes an evaluation device body 10 and a signal acquisition unit 20. The vehicle vibration detection device 1 acquires an electrical signal that can be acquired from an occupant 3 that has boarded the vehicle to be evaluated (in the embodiment, the vehicle 100), and extracts characteristic frequency components from the acquired signal. Analyze the quantity. As a characteristic frequency component, a frequency component of β wave can be cited. Details of the evaluation apparatus body 10 will be described later.

  The signal acquisition unit 20 acquires an electrical signal from an electrode disposed on the head of the occupant 3. In the vehicle vibration detection device 1 according to the embodiment, the signal acquisition unit 20 includes an electrode 21 and an electrode 22. For example, the electrode 21 is disposed at the F3 position based on the International Law 10-20 method, and the electrode 22 is disposed at the F4 position based on the International Law 10-20 method.

  In addition, although not shown, the vehicle vibration detection device 1 includes a plurality of electrodes arranged in Fp1, Fp2, Cz, O3, O4 and the like based on the International Law 10-20. Further, although not shown, for example, a reference electrode disposed on the earlobe or the like is provided. The difference between the potential at the electrodes 21 and 22 and the potential at the reference electrode is amplified by a differential amplifier. Thereby, noise can be removed and a weak electroencephalogram signal can be accurately extracted.

(1-2) Configuration of Vehicle Vibration Detection Device The vehicle vibration detection device 1 includes an evaluation device body 10 and a signal acquisition unit 20. The signal acquisition unit 20 includes the electrodes 21 and 22 described above, and is attached to the head of the occupant 3. Specifically, for example, based on the international law 10-20, it arrange | positions in Fp1, Fp2, F3, F4 position.

  The evaluation apparatus main body 10 includes a signal input unit 11 to which the electrical signal acquired by the signal acquisition unit 20 is supplied, an analysis unit 12 that analyzes the electrical signal supplied to the signal input unit 11, and an electrical signal generated by the analysis unit 12. And a display unit 13 for displaying the result of the analysis.

  The evaluation apparatus main body 10 also includes an input unit 14 such as a keyboard and a mouse that receives input from the user, and a storage unit 15 including a hard disk drive, a semiconductor memory, and the like. The storage unit 15 includes a reference associated with an electrical signal acquired from an electrode arranged on the head of a subject given vibration based on the International Law 10-20 method and a vibration frequency given to the subject. Is remembered.

  In the present embodiment, the analysis unit 12 includes a frequency analysis calculation unit 121 and a specific analysis unit 122. The analysis unit 12 performs time frequency analysis of the acquired electrical signal. The analysis unit 12 may acquire an electrical signal while switching the electrodes 21 and 22 (that is, while changing the measurement site), and may perform time-frequency analysis of the acquired electrical signal (see the modification).

  The frequency analysis calculation unit 121 performs time frequency analysis of the electrical signal. The electroencephalogram is roughly classified into four types, δ wave, θ wave, α wave, and β wave, depending on the frequency band. For example, the δ wave is an electroencephalogram having a frequency band of less than 4 Hz. The δ wave does not appear when awake, but frequently appears during deep sleep. The θ wave is an electroencephalogram having a frequency band of 4 Hz or more and less than 8 Hz. Appears frequently during light sleep. The α wave is an electroencephalogram having a frequency band of 8 Hz or more and less than 13 Hz. Appears conspicuously on the occipital side when the eyes are resting, and the appearance is suppressed when the eyes are opened. It is also an index for evaluating relaxation. The β wave is an electroencephalogram having a frequency band of 13 Hz or higher, is dominant in the frontal region and the temporal region, and has little regularity.

  In the present embodiment, frequency analysis is performed to extract the spectrum of the frequency component in the frequency band affected by the frequency of the vehicle from the electrical signals acquired from the positions Fp1, Fp2, F3, and F4. In particular, it is preferable to perform a frequency analysis that extracts a spectrum of a frequency component corresponding to a β wave. As the frequency analysis, fast Fourier transform, wavelet transform, or the like can be used. In this embodiment, fast Fourier transform is used.

  The specific analysis unit 122 is a reference associated with an electrical signal acquired from an electrode placed on the subject's head given vibration according to the International Law 10-20 method and a vibration frequency given to the subject. Then, the frequency is specified based on the spectrum extracted by the frequency analysis calculation unit 121. Specifically, factor analysis (FA) is performed as multivariate analysis on the frequency component of the electrical signal obtained by the frequency analysis calculation unit 121. Thereby, the factor load is calculated. The frequency is specified according to the value calculated by the calculated factor load and the mathematical expression indicating the reference boundary line. Factor analysis is a technique for finding a latent factor that cannot be directly measured based on the correlation of many measured variables.

(1-3) Derivation of mathematical expression indicating boundary line Electric signal acquired from electrodes arranged based on international method 10-20 on subject's head given vibration and vibration of vibration given to subject The reference associated with the number serves as an index for specifying the vibration frequency felt by the occupant. In this embodiment, the reference associated with the electrical signal obtained from the electrode placed on the head of the subject given the vibration based on the International Law 10-20 method and the frequency of the vibration given to the subject, That is, the mathematical expression indicating the boundary line is derived by the following method. In addition, in order to derive | require the numerical formula which shows a boundary line, what has the structure similar to the above-mentioned vehicle vibration detection apparatus 1 can be used.

  A predetermined frequency is given to the subject while the electrode is mounted on the subject's head. An electrical signal is acquired from the subject while a predetermined frequency is applied to the subject. By changing the frequency applied to the subject, an electrical signal corresponding to each frequency is obtained from the subject. The electrodes are preferably arranged in the frontal region, in particular at positions Fp1, Fp2, F3, F4 based on the international method 10-20. The passenger 3 and the subject may be the same. Moreover, you may acquire the electrical signal according to each frequency from several test subjects.

  The time frequency analysis of the electrical signal supplied from the signal acquisition unit 20 is performed. Specifically, the electroencephalogram in the frequency band is separated from the electrical signal acquired from the head (frontal head) after a certain time has elapsed from the time at which the predetermined frequency is given by fast Fourier transform. That is, a spectrum of frequency components in a predetermined frequency band is extracted. The frequency band at this time is preferably the β band. Factor analysis is performed as multivariate analysis on the frequency components of the electrical signal obtained by the frequency analysis step. Thereby, a plurality of factor loadings are calculated. Among a plurality of factor load amounts, a factor load amount having a cumulative contribution rate of 60% or more is determined from a factor load amount having a high contribution rate. Similarly, the factor load corresponding to each frequency obtained from the subject is determined. Thereby, a plurality of extracted spectra (hereinafter referred to as reference spectra) and the vibration frequencies are associated with each other.

  The reference spectrum is classified into a plurality of classes according to the frequency. Specifically, the class range can be arbitrarily determined according to the frequency value. For example, the class range can be determined such as 0 to 10 Hz, 10 to 20 Hz, and so on. The reference spectrum is classified according to the range of the class. For example, a reference spectrum obtained when a frequency of 7 Hz is given is classified into a class of 0 to 10 Hz. The reference spectrum obtained when a frequency of 15 Hz is given is classified into a class of 10 to 20 Hz.

  From the reference spectrum and the classified class, an equation of a boundary line for dividing the class is calculated. Specifically, a linear equation (LDA) is used to calculate a boundary equation that minimizes intra-class variance and maximizes inter-class variance.

  The intra-class variance is obtained based on the factor loading of the reference spectrum classified into one class. The interclass variance is obtained based on the factor loading of the reference spectrum classified into one class and the factor loading of the reference spectrum classified into another class. As a result, a parameter representing the expression of the boundary line for dividing the class is calculated. A boundary line formula is derived based on the calculated parameters. That is, the mathematical expression indicating the boundary line is associated with the acquired electrical signal and the vibration frequency.

  A plurality of mathematical expressions indicating the boundary line may be derived. For example, a plurality of mathematical expressions indicating boundary lines may be derived according to the frequency range to be detected. Specifically, for example, when classifying into classes of 0 to 10 Hz, 10 to 20 Hz,..., 90 to 100 Hz, a plurality of mathematical formulas indicating boundary lines may be derived.

(2) Description of Detection Method for Detecting Vehicle Frequency Next, a detection method for detecting the vehicle frequency will be described. Specifically, (2-1) Overall description of the evaluation method, (2-2) Step S1: Processing for obtaining an electric signal from the occupant, (2-3) Step S2: Analysis processing, (2-4) Step S3 : Display processing, (2-5) Modification will be described.

(2-1) Overall Description of Evaluation Method FIG. 3 is a flowchart illustrating the evaluation method. As shown in FIG. 3, the evaluation method for evaluating the riding comfort of a bicycle has steps S1, S2, and S3. In step S <b> 1, an electrical signal is acquired from the electrode disposed on the head of the occupant 3. In step S2, the electrical signal is analyzed, and factor analysis is performed as a multivariate analysis on the frequency band components affected by the vehicle frequency. Further, the frequency is specified based on the mathematical expression indicating the boundary line and the factor load obtained by factor analysis. In step S3, the specified frequency is displayed as the frequency transmitted to the passenger.

(2-2) Step S1: Process for Acquiring an Electric Signal from an Occupant In step S1, a process for acquiring an electric signal from an occupant will be specifically described. The occupant gets on the vehicle (vehicle) with the electrode attached to the head. For example, an electric signal is acquired from an occupant during a ride including when the vehicle is running and when the vehicle is stopped.

(2-3) Step S2: Analysis Processing In step S2, first, time frequency analysis of the electrical signal supplied from the signal acquisition unit 20 is performed in step S21. Specifically, fast Fourier transform is performed on the acquired electrical signal. Thereby, the brain wave of a frequency band is isolate | separated from the electrical signal acquired from a head. That is, a spectrum of frequency components in a predetermined frequency band is extracted. The frequency band at this time is preferably the β band. In step S22, factor analysis (FA) is performed as multivariate analysis on the frequency components of the electrical signal obtained in step S21. Thereby, a plurality of factor loadings are calculated. Among a plurality of factor load amounts, a factor load amount having a cumulative contribution rate of 60% or more is determined from a factor load amount having a high contribution rate.

  In step S <b> 23, the frequency is specified based on the mathematical expression indicating the boundary line that is the reference stored in the storage unit 15 and the determined factor load. Specifically, the factor loading determined in step S22 is substituted into an equation indicating a boundary line using a linear discriminant method (LDA). As a result, the extracted spectrum is specified as one of a plurality of categories according to the obtained numerical value. The range of a plurality of categories can be arbitrarily determined.

  For example, in a mathematical expression indicating a boundary line between 0 to 50 Hz and 50 to 100 Hz, when a numerical value obtained by substituting a factor load into a mathematical expression indicating the boundary line is 0 or more, “frequency of 50 to 100 Hz” If the numerical value obtained by substituting the factor load into the mathematical expression indicating the boundary line is less than 0, it is specified in the category of “frequency of 0 to 50 Hz”.

  When a plurality of mathematical expressions indicating the boundary line are derived, the factor load is substituted into the mathematical expression indicating the plurality of boundary lines. The frequency is specified based on a mathematical expression indicating a boundary line where the absolute value of the obtained numerical value is the largest.

(2-4) Step S3
The vibration frequency is displayed on the display unit 13 as the vibration frequency transmitted to the occupant.

(2-5) Modified Examples The present invention can be modified as follows. In addition, the part similar to the said embodiment is abbreviate | omitted suitably.

  In step 1, an electrical signal is obtained from the occupant. Here, in the embodiment, electric signals are acquired from all the electrodes mounted on the head of the occupant. In a modification, an electrical signal is acquired from at least one electrode among the electrodes mounted on the head of the passenger.

  In step S2, the frequency is specified by performing an analysis process based on the acquired electrical signal. In step S3, the specified frequency is displayed on the display unit 13.

  In step S4, it is determined whether or not an electrode that has not acquired an electrical signal among the electrodes mounted on the head of the occupant, that is, an unmeasured electrode remains. If it remains, in step S5, switching is performed so that an electrical signal can be acquired from an unmeasured measurement position. Then, the process of step S1 is repeated. In step S4, when electric signals are acquired from all the electrodes, the process ends.

  According to the modification, since an electrical signal is not acquired from all the electrodes mounted on the head of the occupant, the load on the evaluation apparatus body 10 can be reduced.

(3) Action / Effect According to the vehicle vibration detection device 1 according to the embodiment, the frequency of the vehicle can be detected from the spectrum extracted from the electrical signal acquired from the head of the occupant. For this reason, the vibration frequency of the vehicle acquired from the occupant makes it possible to quantitatively represent an evaluation based on the occupant's sense such as “riding comfort”.

  In the signal acquisition step, it is preferable to acquire an electrical signal from at least one of the electrodes arranged at positions Fp1, Fp2, F3, and F4 based on the International Law 10-20. As a result, the frequency can be detected with high accuracy as will be described later.

  In the analysis step, it is preferable to extract the spectrum of the frequency band component of the β band. As a result, the frequency can be detected with high accuracy as will be described later.

(4) Test for identifying frequency components that can serve as an index (4-1) Test description From the electrical signal (electroencephalogram) that can be used to detect the vibration frequency of a vehicle through the occupant, In order to find the frequency component, the following test was conducted. The measurement conditions are shown below.

  FIG. 5 is a schematic diagram illustrating a test apparatus 200 that detects vehicle vibration performed using the vehicle vibration detection apparatus 1.

  The test apparatus 200 can load the vehicle 100 and can give a predetermined vibration to the vehicle 100. The occupant 3 gets on the vehicle 100 loaded on the test apparatus 200 with the signal acquisition unit 20 mounted on the head. While applying vibration to the vehicle 100, the test apparatus 200 acquires an electrical signal that can acquire an electroencephalogram from the head of the occupant 3 via the signal acquisition unit 20.

  The electrical signals that can be detected from the head of the occupant 3 were measured at each measurement position based on the International Method 10-20, and the characteristics of the spectrum obtained by analyzing the electrical signals detected at each position were analyzed.

・ Subject (passenger): 4 males in their 20s ・ Measurement location: Fp1, Fp2, F3, F4, C3, C4, Cz, O1, O2, T3, T4 based on the international law 10-20
-Load conditions: Vibrations at a frequency of 7 Hz and 40 Hz were applied.

  The subject put on the electroencephalogram measurement electrode at the measurement location and got on the vehicle. Thereafter, the brain wave of the occupant when a fixed frequency was given to the vehicle was analyzed, and the spectrum pattern of the brain wave corresponding to the given frequency was detected.

  According to ISO, the vibration frequency of 7 Hz is set to an excitation frequency “not comfortable to ride”, and the frequency of 40 Hz is set to an excitation frequency “good to ride”.

(4-2) Results (4-2-1) Verification of effective frequency band for evaluation A short-time Fourier transform (window size: 1 second, shift amount: 0.2 seconds) was applied to the detected electroencephalogram. The amplitude spectrum of the electroencephalogram signal was calculated. Amplitude spectra in the θ band (4-6 [Hz]), the α band (8-13 [Hz]), and the β band (14-26 [Hz]) were used for the analysis.

  A significant difference test was performed on the electroencephalogram data acquired when the above two types of vibrations were applied. If there is a divergence of 5% or more, that is, a difference between the electrical signal detected when the vibration of 7 Hz is applied and the electrical signal detected when the vibration of 40 Hz is applied, “significant difference” It was judged. The results are shown in FIG. FIG. 6 is a diagram showing the result of significant difference test. In FIG. 6, among 4 subjects, when 4 people are significantly different, “◎” is significant. When 3 people are significantly different, “◯” is significant for 2 people. When a difference was observed, “□” was assigned, “△” was assigned when a significant difference was found in one person, and “X” was assigned when no significant difference was found.

  As shown in FIG. 6, a significant difference was recognized in the higher frequency band. Specifically, a significant difference was observed in the α band than in the θ band and in the β band rather than the α band. Therefore, it has been found that it is preferable to detect the vibration felt by the occupant using the electroencephalogram data in the β band.

(4-2-2) Verification of frequency band effective for evaluation Next, from the result of FIG. 6, since the most significant difference was recognized in the β band, the analysis was performed using the electroencephalogram data in the β band. For the analysis, a classifier using Mahalanobis distance was applied. Using this discriminator, it was determined whether the given electroencephalogram data was at 7 Hz vibration or 40 Hz vibration. The combination of each measurement location where the electroencephalogram data used for classification was measured was determined one by one. Thereby, the measurement location effective for evaluation was specified. The results are shown in FIG. FIG. 7 is a diagram illustrating a relationship between a measurement location and a classification rate at the measurement location. The numerical value in parentheses indicates the classification rate. It shows that the correct answer rate of determination is so high that a classification rate is high. The underline in parentheses represents the maximum classification rate for each subject. As shown in FIG. 7, it was found that the classification rate exceeded 50% at any measurement location. In particular, in 3 subjects out of 4 subjects (subjects 1, 3 and 4), the electroencephalogram data is classified by using the electroencephalogram data measured from the measurement points located in the frontal region of Fp1, Fp2, F3, and F4. It was found that the rate could be as high as 70% or higher. Therefore, it has been found that it is particularly preferable to detect the vibration felt by the occupant from the measurement points of the frontal head (Fp1, Fp2, F3, F4).

  From this result, it can be assumed that the acquired electroencephalogram data is data in which the influence of the frequency is clearly shown, so it can be classified using a simple classifier. For this reason, it is considered that the vibration felt by the occupant can be detected even when linear discrimination (LDA) that requires a very small amount of calculation is used.

(5) Other Embodiments In the present embodiment, it has been described that factor analysis is performed as multivariate analysis. However, multivariate analysis includes multiple regression analysis and discriminant analysis. In addition, discriminant analysis includes factor analysis and principal component analysis. Any of these analysis methods can be applied.

  In the present embodiment, the vibration frequency of the vehicle 100 is detected, but the present invention is not limited to this. Any vehicle may be used. For example, the frequency of a train may be detected.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle vibration detection apparatus, 3 ... Passenger, 10 ... Evaluation apparatus main body, 11 ... Signal input part, 12 ... Analysis part, 13 ... Display part, 14 ... Input part, 15 ... Memory | storage part, 20 ... Signal acquisition part, 21 DESCRIPTION OF SYMBOLS ... Electrode, 22 ... Electrode, 100 ... Bicycle, 121 ... Frequency analysis calculation part, 122 ... Specific analysis part, 200 ... Test apparatus

Claims (6)

A vehicle vibration detection method for detecting a frequency transmitted from a vehicle to an occupant using a signal obtainable from the occupant,
A signal acquisition step of acquiring an electrical signal from electrodes arranged based on the International Law 10-20 method at a plurality of locations on the head of the occupant;
An analysis step of performing a signal analysis for extracting a spectrum of a frequency band component affected by the frequency of the vehicle from the acquired electrical signal;
Based on electrical signals acquired from electrodes placed on the subject's head in accordance with the International Method 10-20, a reference associated with the frequency of the vibration, and the extracted spectrum And a vehicle vibration detection method having a specific step of specifying a vibration frequency.   2. The vehicle vibration detection method according to claim 1, wherein in the signal acquisition step, an electrical signal is acquired from at least one of the electrodes arranged at positions Fp1, Fp2, F3, and F4 based on the International Law 10-20.   The vehicle vibration detection method according to claim 1, wherein in the analysis step, a spectrum of a frequency band component of a β band is extracted. A vehicle vibration detection device that detects a frequency transmitted from a vehicle to an occupant using a signal that can be acquired from the occupant,
Based on international law 10-20, a signal acquisition unit that acquires electrical signals from electrodes arranged in a plurality of locations on the head of the occupant;
A signal analysis unit for performing signal analysis for extracting a spectrum of a frequency band component affected by the frequency of the vehicle from the acquired electrical signal;
Based on electrical signals acquired from electrodes placed on the subject's head in accordance with the International Method 10-20, a reference associated with the frequency of the vibration, and the extracted spectrum A vehicle vibration detection device having a specific analysis unit for specifying a vibration frequency.   The vehicle vibration detection device according to claim 4, wherein the signal acquisition unit acquires an electrical signal from at least one of the electrodes arranged at positions Fp1, Fp2, F3, and F4 based on the International Law 10-20.   The vehicle vibration detection device according to claim 4, wherein the signal analysis unit extracts a spectrum of a frequency band component of a β band.

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