JP2008244766A - Onboard acoustic diagnosis unit, onboard acoustic system, control method for onboard acoustic diagnosis unit, and control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To objectively detect the deterioration of an onboard acoustic system (particularly speaker) based on a quantitative judgment free from personal feelings on sound in such a relatively slight state that a user is not aware of. <P>SOLUTION: An onboard acoustic diagnosis unit for diagnosing an acoustic characteristic of an onboard acoustic system 100 having a plurality of speakers 21-26, and having a plurality of microphones 31-36 respectively corresponding to the speakers 21-26, generates a predetermined measurement signal for diagnosing the acoustic characteristic, individually supplies measurement signals to the plurality of speakers 21-26 in succession, so as to collect output measurement sounds via the microphones 31-36, performs the calculation of a transfer function and the measurement of a time response characteristic, and performs diagnosis of the acoustic characteristic of the onboard acoustic system 100 based on the calculated transfer function and the measured time response characteristic. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle acoustic diagnosis apparatus, a vehicle acoustic system, a control method and a control program for a vehicle acoustic diagnosis apparatus, and in particular, for diagnosing deterioration of an acoustic system including a speaker constituting the vehicle acoustic system. Related to technology.

Conventionally, it is known that there are several factors in the deterioration of speaker characteristics.
Specifically, it is rattling due to deterioration of the edge portion with time and looseness of the attachment portion, and metal corrosion due to salt damage in some areas. In addition, factors such as poor contact of the terminal portion, cable disconnection, and deterioration of cone paper may be considered.
On the other hand, the frequency characteristic of the speaker should ideally be flat within the reproduction band, and the group delay characteristic (gradient of the phase characteristic) should be constant. In reality, however, each speaker has its own characteristics.

Further, in a speaker used in an in-vehicle acoustic system, there is a case in which the low frequency region is intentionally enhanced so that the low frequency region sound is not canceled by road noise.
By the way, the deterioration of the characteristics of the speaker means that the frequency characteristics and phase characteristics specific to these individual speakers change.
When these characteristic deteriorations are slight, they are not perceived by human ears, so the driver or passenger (hereinafter referred to as the user) often notices the deterioration without being aware of it. Will not improve.
Therefore, it is common to notice the deterioration of the characteristic only after the deterioration becomes remarkable and the user feels uncomfortable feeling.

Here, a conventional acoustic characteristic evaluation technique will be described.
FIG. 9 is a conceptual explanatory diagram as an input / output system of a speaker.
As shown in FIG. 9, a speaker is considered as an input / output system that outputs a signal y (t) when a signal x (t) is input. Here, x (t) and y (t) are signals on the time axis having the time t as an argument.
If the system characteristics are h (t) and the Fourier transforms of x (t), y (t), and h (t) are X (ω), Y (ω), and H (ω), respectively, Thus, H (ω) is called the transfer function of this system. Here, ω is an angular frequency.
Y (ω) = H (ω) × X (ω) (Formula 1)
In order to mathematically grasp the characteristics {h (t) or H (ω)} of the input / output system, a unit impulse signal δ (t) is input to the system and its output is observed. The unit impulse signal δ (t) is a pulse signal having an amplitude of 1 only at the instant of time zero and zero in other cases. Expressed by the formula, it is expressed by the following formula 2-1 and formula 2-2.
δ (t) = 1 (when t = 0) (Formula 2-1)
δ (t) = 0 (when t ≠ 0) (Formula 2-2)

Incidentally, it is well known that the unit impulse signal δ (t) includes all frequency components.
Since the Fourier transform of the unit impulse is 1 regardless of ω, when the input signal x (t) is a unit impulse signal,
H (ω) = 1
Therefore, the output signal is from (Equation 1)
Y (ω) = H (ω) (Equation 3)
It becomes.
From this, the transfer function of the system can be obtained by inputting the impulse signal to the system and subjecting the output to Fourier transform.
When actually checking the acoustic characteristics of a speaker, an impulse signal is input to the speaker and the sound emitted from the speaker is recorded by a microphone. This output signal is called an impulse response.
A technique for obtaining a transfer function of a speaker by subjecting the recorded signal to a Fourier transform is generally used (see, for example, Patent Document 1).

In actual measurement, a burst sound such as applause or a competition pistol may be used as an impulse signal. Also, instead of the impulse signal, a TSP (Time Stretched Pulse) signal generated by changing the phase of each frequency component included in the impulse in proportion to the square of the frequency may be used. This is a technique well known as a “TSP method” for measuring an impulse response.
JP-A-11-285100

By the way, in a speaker constituting an in-vehicle acoustic system, if a relatively slight deterioration in sound quality that the user does not notice is left unattended, the user will be uncomfortable when the deterioration in sound quality becomes significant.
Also, since the allowable range for sound quality varies depending on the individual, if the deterioration is relatively minor, even if the sound quality does not cause a problem for one user, another user may feel uncomfortable.
Accordingly, an object of the present invention is not influenced by the user's personal sensation, but is comparatively insignificant so that the user does not notice deterioration of the in-vehicle acoustic system (especially a speaker) objectively based on numerical judgment. It is possible to detect an on-board acoustic diagnosis apparatus, an on-vehicle acoustic system, a control method for an on-vehicle acoustic diagnosis apparatus, and a control program.

  In order to solve the above problems, an on-vehicle acoustic diagnostic apparatus for diagnosing the acoustic characteristics of an on-vehicle acoustic system having a plurality of speakers, the one or a plurality of microphones corresponding to each of the speakers, and a predetermined acoustic characteristic diagnosis A measurement signal generation unit that generates a measurement signal for use, a switching selection unit that sequentially supplies the measurement signal output from the measurement signal generation unit to a plurality of speakers, and the measurement signal. A signal processing unit that collects measurement sound output from each of the speakers via the microphone, calculates a transfer function and measures a time response characteristic, the transfer function calculated by the signal processing unit, and a measured time response A diagnostic unit that performs acoustic characteristic diagnosis of the in-vehicle acoustic system based on characteristics.

According to the above configuration, the measurement signal generation unit generates a predetermined measurement signal for acoustic characteristic diagnosis.
The switching selection unit sequentially supplies the measurement signals output from the measurement signal generation unit to a plurality of speakers sequentially.
Accordingly, the signal processing unit collects the measurement sound output from each speaker by supplying the measurement signal through the microphone, and calculates the transfer function and the time response characteristic.
And a diagnostic part performs the acoustic characteristic diagnosis of a vehicle-mounted acoustic system based on the transfer function which the signal processing part computed, and the measured time response characteristic.
Therefore, it is possible to detect the deterioration of the in-vehicle acoustic system (particularly the speaker) in a relatively light state that the user does not notice, objectively based on the numerical judgment, without being influenced by the user's personal hearing. .

In this case, an initial characteristic that stores in advance an initial transfer function that is a transfer function corresponding to each speaker in the initial state of the in-vehicle acoustic system and an initial response characteristic that is a time response characteristic corresponding to each speaker in the initial state A storage unit, wherein the diagnosis unit performs the acoustic characteristic diagnosis by referring to the initial transfer function and the initial response characteristic for the transfer function calculated by the signal processing unit and the measured time response characteristic. Also good.
According to the above configuration, the acoustic characteristic diagnosis can be performed by a simple comparison process.
Further, the diagnosis unit determines whether the frequency characteristic, the phase characteristic, or the time response characteristic of each speaker exceeds an allowable range based on the transfer function calculated by the signal processing unit and the measured time response characteristic. If there is a characteristic that exceeds the allowable range, the acoustic characteristic diagnosis that the acoustic characteristic has deteriorated in the in-vehicle acoustic system may be performed.
Therefore, it is possible to reliably diagnose the deterioration of the acoustic characteristics.

In addition, when the diagnosis unit determines that the variation of the frequency characteristic, the phase characteristic, or the time response characteristic exceeds a permissible range for a part of the plurality of speakers, the diagnosis unit exceeds the permissible range. You may make it perform the said acoustic characteristic diagnosis that the said speaker which has deteriorated.
According to the above configuration, it is possible to reliably diagnose the deterioration of the acoustic characteristics due to the deterioration of the speaker.
In addition, when the diagnosis unit determines that the variation in the frequency characteristic, the phase characteristic, or the time response characteristic exceeds the allowable range for all of the plurality of speakers, in the on-vehicle acoustic system, You may make it perform the said acoustic characteristic diagnosis that the part has degraded.
According to the above configuration, it is possible to reliably diagnose deterioration of acoustic characteristics due to deterioration of parts other than the speaker of the in-vehicle acoustic system.

Further, when the acoustic characteristic diagnosis that the acoustic characteristic is deteriorated is made by the diagnostic part, a notification part for notifying the fact may be provided.
According to the said structure, the user can know deterioration of an acoustic characteristic easily.

A plurality of speakers; one or a plurality of microphones corresponding to each of the speakers; a measurement signal generation unit that generates a predetermined measurement signal for acoustic characteristic diagnosis; and the measurement signal output from the measurement signal generation unit A switching selection unit that sequentially and individually supplies a plurality of speakers, and a measurement sound output from each of the speakers when the measurement signal is supplied is collected via the microphone, and a transfer function calculation and time A signal processing unit that measures response characteristics; and a diagnosis unit that diagnoses acoustic characteristics of the in-vehicle acoustic system based on the transfer function calculated by the signal processing unit and the measured time response characteristics. .
According to the above configuration, the deterioration of the in-vehicle acoustic system (particularly the speaker) is objectively detected based on numerical judgment in a relatively light state that the user does not notice, regardless of the user's personal hearing. can do.

A method for controlling an on-vehicle acoustic diagnosis apparatus for diagnosing the acoustic characteristics of an on-vehicle acoustic system having a plurality of speakers, the measurement signal generating process for generating a predetermined measurement signal for acoustic characteristic diagnosis, and the measurement A switching selection process for sequentially supplying signals to a plurality of speakers individually, and a measurement sound output from each speaker by supplying the measurement signal via one or a plurality of microphones corresponding to each speaker A signal processing process for collecting sound and calculating a transfer function and measuring a time response characteristic; and a diagnosis process unit for diagnosing an acoustic characteristic of the in-vehicle acoustic system based on the calculated transfer function and the measured time response characteristic. It is characterized by providing.
According to the above configuration, the deterioration of the in-vehicle acoustic system (particularly the speaker) is objectively detected based on numerical judgment in a relatively light state that the user does not notice, regardless of the user's personal hearing. can do.

A control program for diagnosing the acoustic characteristics of an in-vehicle acoustic system having a plurality of speakers and for controlling an on-vehicle acoustic diagnosis apparatus having one or a plurality of microphones corresponding to each of the speakers by a computer, A measurement signal for diagnosing the acoustic characteristics of each of the plurality of loudspeakers is generated, the measurement signals are individually supplied to a plurality of speakers, and the measurement sound output from each speaker is supplied via the microphone. Characterized in that the sound characteristics of the in-vehicle acoustic system are diagnosed based on the calculated transfer function and the measured time response characteristic. Yes.
According to the above configuration, the deterioration of the in-vehicle acoustic system (particularly the speaker) is objectively detected based on numerical judgment in a relatively light state that the user does not notice, regardless of the user's personal hearing. can do.
In this case, the control program may be recorded on a computer-readable recording medium.

  According to the present invention, the deterioration of the in-vehicle acoustic system (especially a speaker) is objectively detected based on a numerical judgment in a relatively small state that the user does not notice, regardless of the user's personal hearing. The user can respond early.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the main configuration of an in-vehicle acoustic system.
The on-vehicle acoustic system 100 of this embodiment has a sound quality deterioration detection function of a speaker.
The in-vehicle acoustic system 100 is roughly classified into a control unit 1, an operation unit 2, a display unit 3, a measurement signal generation unit 4, a recording medium reproduction unit 5, a first signal switching unit 6, a switching selection unit 7, and a power amplifier 8. , A microphone amplifier 9, a second signal switching unit 10, a signal processing unit 11, a first storage unit 12, a diagnosis unit 13, speakers 21 to 26, and microphones 31 to 36.

The control unit 1 functions as a computer that controls the entire system of the in-vehicle acoustic system 100, and includes a CPU (Central Processing Unit) (not shown) and a ROM (Read Only Memory) (not shown) that stores a control program executed by the CPU. A RAM (Random Access Memory) (not shown) that temporarily stores various data and a second storage unit 1A that stores sound quality deterioration detection data in a nonvolatile manner are provided.
The operation unit 2 includes an operation switch operated by the user, inputs an operation instruction from the user via the operation switch, and notifies the control unit 1 of the operation instruction.
The display unit 3 includes a liquid crystal display device and displays various images under the control of the control unit 1.

The measurement signal generating unit 4 outputs an impulse signal (measurement signal) to the first signal switching unit 6.
The recording medium playback unit 5 includes a CD or DVD playback device, reads data recorded on the CD or DVD under the control of the control unit 1, performs decoding processing, and converts the audio analog signal into the first signal switching unit 6. Output to.

The first signal switching unit 6 normally selects the recording medium playback unit 5 side and outputs an audio analog signal to the switching selection unit 7. When the sound quality deterioration of the speakers 21 to 26 is detected, the measurement signal generation unit 4 side is selected, and an impulse signal is output to the switching selection unit 7.
The switching selection unit 7 is a power amplifier for 6-channel (L, C, R, Ls, Rs, SW channel) audio analog signals supplied from the recording medium playback unit 5 via the first signal switching unit 6 during normal operation. 8 to the speakers 21 to 26. Further, when the sound quality deterioration of the speakers 21 to 26 is detected, the impulse signal supplied from the measurement signal generation unit 4 via the first signal switching unit 6 is sequentially supplied to the sound quality deterioration detection target speaker via the power amplifier 8. .
The microphone amplifier 9 receives 6-channel audio inputs from the microphones 31 to 36 individually corresponding to the speakers 21 to 26, amplifies them, and outputs them to the second signal switching unit 10.

Here, with reference to FIG. 2, correspondence and arrangement relationship between the speakers 21 to 26 and the microphones 31 to 36 will be described.
FIG. 2 is a diagram showing the arrangement of speakers and microphones in the vehicle.
As shown in FIG. 2, the front right speaker 21 is disposed on the front right side of the driver seat 41 of the vehicle 40, and the center speaker 22 is disposed in front of the driver seat 41 and the front passenger seat 42. 23 is disposed on the front left side of the passenger seat 42, the subwoofer 24 is disposed on the rear center of the rear seat 43, the rear right speaker 25 is disposed on the rear right side of the rear seat 43, and the rear left speaker 26 is disposed on the rear side. It is arranged on the rear left side of the seat 43.
On the other hand, the microphone 31 is provided at a position where sound corresponding to the impulse signal emitted from the front right speaker 21 can be directly collected without passing through a shield, for example, at the ceiling of the vehicle. Similarly, the microphone 32 is provided at a position where sound corresponding to the impulse signal emitted from the center speaker 22 can be directly collected without passing through a shield, and the microphone 33 is emitted from the front left speaker 23. The sound corresponding to the impulse signal is collected at a position where sound can be directly collected without passing through the shield, and the microphone 34 directly collects the sound corresponding to the impulse signal emitted from the subwoofer 24 without passing through the shield. The microphone 35 is provided at a position where sound can be directly collected without passing through a shielding object corresponding to the impulse signal emitted from the rear right speaker 25. The sound corresponding to the impulse signal emitted from the speaker 26 is provided at a position where sound can be directly collected without passing through a shield.

The second signal switching unit 10, when detecting the sound quality deterioration of the speakers 21 to 26, is analog corresponding to the sound corresponding to the impulse signal supplied from the microphones 31 to 36 via the microphone amplifier 9 under the control of the control unit 1. The signals are sequentially supplied to the signal processing unit 11 in association with the speaker whose sound quality is to be detected.
The signal processing unit 11 processes an analog signal corresponding to the sound corresponding to the impulse signal separately supplied from each of the microphones 31 to 36 via the microphone amplifier 9, calculates its transfer function and time response characteristics, Supply to the diagnosis unit 13.
The first storage unit 12 stores an initial transfer function and an initial time response characteristic for each of the speakers 21 to 26 in advance, for example, at the time of factory shipment.

The diagnosis unit 13 transmits the transfer function and the time response characteristic for each speaker 21 to 26 supplied from the signal processing unit 11 when the sound quality deterioration is detected to the initial transmission for each speaker 21 to 26 stored in the first storage unit 12. By comparing with the function and the initial time response characteristic, the sound quality deterioration state of each of the speakers 21 to 26 is diagnosed, and the diagnosis result is output to the control unit 1.
Next, the operation of the in-vehicle acoustic system of the embodiment will be described.
In the following description, the vehicle-mounted acoustic system 100 will be described by dividing it into an initial setting at the time of shipment and an acoustic characteristic diagnosis after shipment.
First, the in-vehicle acoustic system 100 has an initial transfer function that is a transfer function corresponding to each speaker 21 to 26 and an initial time characteristic that is a time response characteristic corresponding to each speaker 21 to 26 in the second storage unit 1A at the time of shipment. It has come to be remembered.

FIG. 3 is a flowchart of storage processing of acoustic characteristic data at the time of shipment (initial state).
Here, a transfer function and a time response characteristic are stored as the acoustic characteristic data.
Before shipping, the operator operates the operation switch of the operation unit 2 to instruct the in-vehicle acoustic system 100 to store the acoustic characteristic data in the initial state.
Thereby, the control unit 1 controls the measurement signal generation unit 4 to cause the measurement signal generation unit 4 to generate an impulse signal (measurement signal), and to output the impulse signal (measurement signal) to the first signal switching unit 6 (step S11).
In parallel with this, the control unit 1 causes the first signal switching unit 6 to select the measurement signal generation unit 4 side, causes the switching selection unit 7 to output an impulse signal, and further causes the switching selection unit 7 to output the first signal switching unit 6. The impulse signal supplied from the measurement signal generator 4 via the speaker is supplied to the sound quality deterioration detection target speaker, specifically, for example, the front right speaker 21 via the power amplifier 8, and the sound quality deterioration detection target speaker is supplied. To output a sound corresponding to the impulse signal.

As a result, the sound corresponding to the impulse signal output from the speaker targeted for sound quality degradation detection is recorded by the corresponding microphone (step S13). Specifically, when the sound quality deterioration detection target speaker is the front right speaker 21, sound corresponding to the impulse signal output via the microphone 31 is recorded.
Thereby, the microphone amplifier 9 receives 6-channel audio inputs from the microphones 31 to 36 individually corresponding to the speakers 21 to 26, respectively amplifies them, and outputs them to the second signal switching unit 10.

FIG. 4 is an explanatory diagram of an example of frequency characteristics as a transfer function.
FIG. 5 is an explanatory diagram of an example of the time response characteristic as the time response characteristic.
FIG. 6 is an explanatory diagram of an example of phase characteristics as a transfer function.
Under the control of the control unit 1, the second signal switching unit 10 sequentially associates the impulse signals supplied from the microphones 31 to 36 via the microphone amplifier 9 with the sound quality deterioration detection target speakers and sends them to the signal processing unit 11. The signal processing unit 11 processes the analog signals corresponding to the impulse signals separately supplied from the microphones 31 to 36 via the microphone amplifier 9 by Fourier transform processing, and the transfer function (initial transfer function: concrete) Specifically, the frequency characteristic CF _INIT shown in FIG. 4 and the phase characteristic CP _INIT shown in FIG. 6 and the time response characteristic (initial time response characteristic: specifically, the time response characteristic P _INIT shown in FIG. 5) are calculated. Then, it supplies to the 1st memory | storage part 12 via the diagnostic part 13 (step S14).
As a result, the first storage unit 12 stores the initial transfer function and the initial time response characteristic for each speaker (step S15). Specifically, in the case of the above example, the initial transfer function and the initial time response characteristic of the front right speaker 21 are stored in the first storage unit 12.

Next, the control unit 1 determines whether or not the calculation of the initial transfer function and the measurement of the initial time response characteristics have been completed for all the speakers 21 to 26 (step S16).
In the determination in step S16, when the calculation of the initial transfer function and the measurement of the initial time response characteristics are not yet completed for all the speakers 21 to 26 (step S16; No), the process proceeds to step S11 again. The same processing is repeated until the calculation of the initial transfer function and the measurement of the initial time response characteristics are completed for all the speakers 21 to 26 and stored in the first storage unit 12.
In the determination of step S16, when the measurement of the initial transfer function and the initial time response characteristic is completed for all the speakers 21 to 26 (step S16; Yes), the process is terminated.

Next, processing at the time of acoustic characteristic diagnosis after shipment will be described.
FIG. 7 is a process flowchart (1) at the time of acoustic characteristic diagnosis after shipment.
FIG. 8 is a processing flowchart (2) at the time of acoustic characteristic diagnosis after shipment.
First, the control unit 1 determines whether or not it is time to execute diagnosis (step S21).
Specifically, after the start of use of the vehicle on which the in-vehicle acoustic system 100 is installed, the acoustic characteristic characteristic diagnosis is performed once every six months or once or more every six months or in a schedule that can be arbitrarily set by the user. What is necessary is just to set so. In this case, the acoustic characteristic diagnosis schedule is input by the user in the operation unit 2, and the information is stored in the second storage unit 1 </ b> A of the control unit 1. Note that the schedule may use the initial value determined by the vehicle manufacturer and recorded in the second storage unit 1A in advance. Moreover, it is also possible to configure so that the acoustic characteristic diagnosis is performed at a timing desired by the user separately from the schedule.

If it is not time to execute the acoustic characteristic diagnosis in the determination in step SS21 (step S21; No), the acoustic characteristic diagnosis process is terminated.
In the determination in step S21, when it is time to execute the acoustic characteristic diagnosis, when the user starts the engine for the first time after the diagnosis due date determined in the schedule arrives, or the vehicle key is set to the accessory (ACC) position. When turned (step S21; Yes), the control unit 1 controls the display unit 3 to display a message indicating that the diagnosis time has come.
Thus, when the user inputs a diagnosis start command via the operation unit 2 (step S23), the diagnosis is started.
That is, the control unit 1 controls the measurement signal generation unit 4, causes the measurement signal generation unit 4 to generate an impulse signal (measurement signal), and causes the first signal switching unit 6 to output it (step S24).
In parallel with this, the control unit 1 causes the first signal switching unit 6 to select the measurement signal generation unit 4 side, causes the switching selection unit 7 to output an impulse signal, and further causes the switching selection unit 7 to output the first signal switching unit 6. The impulse signal supplied from the measurement signal generator 4 via the speaker is supplied to the sound quality deterioration detection target speaker, specifically, for example, the front right speaker 21 via the power amplifier 8, and the sound quality deterioration detection target speaker is supplied. To output a sound corresponding to the impulse signal (step S25).
As a result, the sound corresponding to the impulse signal output from the speaker targeted for sound quality deterioration detection is recorded by the corresponding microphone (step S26). Specifically, when the sound quality deterioration detection target speaker is the front right speaker 21, sound corresponding to the impulse signal output via the microphone 31 is recorded.

Thereby, the microphone amplifier 9 receives 6-channel audio inputs from the microphones 31 to 36 individually corresponding to the speakers 21 to 26, respectively amplifies them, and outputs them to the second signal switching unit 10.
Under the control of the control unit 1, the second signal switching unit 10 sequentially associates the impulse signals supplied from the microphones 31 to 36 via the microphone amplifier 9 with the sound quality deterioration detection target speakers and sends them to the signal processing unit 11. The signal processing unit 11 processes the analog signal corresponding to the impulse signal separately supplied from the microphones 31 to 36 via the microphone amplifier 9 by Fourier transform processing, and the transfer function (specifically, The frequency characteristic CF _SAMP shown in FIG. 4 and the phase characteristic CP _SAMP shown in FIG. 6 and the time response characteristic (specifically, the time response characteristic P _SAMP shown in FIG. 5) are calculated (step S27), and the diagnosis unit 13 is calculated. To the first storage unit 12 (step S28).

Next, the control unit 1 determines whether or not the transfer function calculation and the time response characteristic measurement have been completed for all the speakers 21 to 26 (step S29).
If it is determined in step S29 that transfer function calculation and time response characteristic measurement have not yet been completed for all the speakers 21 to 26 (step S29; No), the process returns to step S24, and all The same processing is repeated until the calculation of the transfer function and the measurement of the time response characteristics for the speakers 21 to 26 are completed and stored in the first storage unit 12.
In the determination in step S29, when the measurement of the transfer function and the time response characteristic is completed for all the speakers 21 to 26 (step S29; Yes), the diagnosis unit 13 has been stored in the first storage unit 12. The initial transfer function and the initial time response characteristic are read (step S30).

Subsequently, the diagnosis unit 13 determines the allowable range for performing acoustic characteristic diagnosis (a reference value for the level difference of the frequency characteristic, a reference value for the pulse detection time difference of the time response characteristic, and a reference value for the phase delay amount of the phase characteristic) Etc.) is read from the second storage unit 1A of the control unit 1 (step S31).
Furthermore, the diagnosis unit 13 compares the frequency characteristic CF _INIT as the initial transfer function with the frequency characteristic CF _SAMP and compares the time response characteristic P _INIT as the initial time response characteristic with the time response characteristic P _SAMP. Then, the phase characteristic CP _INIT as the initial transfer function is compared with the phase characteristic CP _SAMP (step S32).
Next, the control unit 1 determines whether or not transfer function comparison and time response characteristic comparison have been completed for all the speakers 21 to 26 (step S33).
If it is determined in step S33 that the transfer function comparison and the time response characteristic comparison have not been completed for all the speakers 21 to 26 (step S33; No), the process proceeds to step S32 again. Similar processing is repeated until the comparison of the transfer functions and the comparison of the time response characteristics of the speakers 21 to 26 are completed.

In the determination of step S32, when the comparison of the transfer functions and the comparison of the time response characteristics are completed for all the speakers 21 to 26 (step S32; Yes), the diagnosis unit 13 determines the transfer function comparison results and the time response characteristics. In the comparison result, it is determined whether or not there is a fluctuation exceeding the allowable range (step S34).
In the determination in step S34, if there is a fluctuation exceeding the allowable range in the transfer function comparison result and the time response characteristic comparison result (step S34; Yes), the diagnosis unit 13 determines all the speakers 21 to 26. It is determined whether or not uniform deterioration has been detected (step S35).
In the determination in step S35, when uniform deterioration is detected for all the speakers 21 to 26 (step S36; Yes), the diagnosis unit 13 notifies the control unit 1 to that effect, and the control unit 1 Then, maintenance recommendation information that suggests deterioration of the sound system other than the speakers 21 to 26 is displayed on the display unit 3 (step S36), and the process is terminated.
That is, if all the speakers 21 to 26 are deteriorated to the same extent, it is very unlikely that all the speakers 21 to 26 are actually deteriorated to the same extent by all means, so that the acoustic signal system other than the speakers 21 to 26 ( For example, the possibility that the recording microphone or the output system in the set such as an amplifier is deteriorated is indicated on the display unit, and maintenance is recommended.

  In the determination of step S35, when deterioration is detected for some of the speakers 21 to 26 (step S36; No), the diagnosis unit 13 notifies the control unit 1 to that effect, and the control unit 1 displays the display. It suggests that the deterioration has been detected for any of the speakers 21 to 26 in the unit 3, displays maintenance recommendation information for the speaker (step S37), and ends the process. Specifically, if the level fluctuation of the frequency characteristic or the fluctuation of the phase characteristic exceeds the allowable range, a message that a change in the acoustic characteristic that cannot be ignored is displayed on the display unit 3, and the characteristic is displayed. After clarifying that the cause of the change is due to speaker deterioration, we recommend maintenance. Alternatively, maintenance is recommended after clarifying that the cause of characteristic changes is due to temporary environmental changes (such as loading luggage) in the passenger compartment.

In the determination in step S34, if there is no fluctuation exceeding the allowable range in the transfer function comparison result and the time response characteristic comparison result (step S34; No), that is, both are compared with the initial characteristic. If there is no difference or the difference is within the allowable range, the diagnosis unit 13 notifies the control unit 1 of the diagnosis result “no abnormality”, and the control unit 1 displays that fact on the display unit 3. (Step S38), and the process ends.
As described above, according to the present embodiment, the user does not notice the deterioration of the on-vehicle acoustic system (particularly the speaker) objectively based on numerical judgments without being influenced by the user's personal hearing. Can be detected in a relatively minor state, and the user can respond quickly.
In the above description, the case where the microphones 31 to 36 are provided on the ceiling of the vehicle has been described. However, the microphones 31 to 36 may be provided adjacent to the corresponding speakers 21 to 26.
In the above description, the case where the impulse signal is used as the measurement signal has been described. However, instead of the impulse signal, the TSP signal generated by changing the phase of each frequency component included in the impulse in proportion to the square of the frequency. It is also possible to use.

In the above description, the case where the control program for realizing the above functions is stored in the ROM in advance has been described. However, the control program may be recorded on a computer-readable recording medium. With such a configuration, when the program is read from the storage medium by the computer and the computer executes processing according to the read program, the same operation and effect as those of the image information processing apparatus of the above-described embodiment can be obtained.
Here, the storage medium is a semiconductor storage medium such as RAM or ROM, a magnetic storage type storage medium such as FD or HD, an optical reading type storage medium such as CD, CDV, LD, or DVD, or a magnetic storage type such as MO. / Optical reading type storage medium, and any storage medium can be used as long as it can be read by a computer regardless of electronic, magnetic, optical, etc. .
It is also possible to download, install, and execute a control program via a communication network such as the Internet or a LAN.

It is a block diagram which shows the main structures of a vehicle-mounted audio system. It is a figure which shows arrangement | positioning of the speaker and microphone in a vehicle. It is a storage processing flowchart of the acoustic characteristic data at the time of shipment (initial state). It is explanatory drawing of an example of the frequency characteristic as a transfer function. It is explanatory drawing of an example of the time response characteristic as a time response characteristic. It is explanatory drawing of an example of the phase characteristic as a transfer function. It is a process flowchart (1) at the time of the acoustic characteristic diagnosis after shipment. It is a process flowchart (2) at the time of the acoustic characteristic diagnosis after shipment. It is a conceptual explanatory view as an input / output system of a speaker.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control part 1A 2nd memory | storage part 2 Operation part 3 Display part 4 Measurement signal generation part 5 Recording medium reproduction | regeneration part 6 1st signal switching part 7 Switching selection part 8 Power amplifier 9 Microphone amplifier 10 2nd signal switching part 11 Signal processing part DESCRIPTION OF SYMBOLS 12 1st memory | storage part 13 Diagnosis part 21-26 Speaker 31-36 Microphone 40 Vehicle 41 Driver's seat 42 Passenger's seat 43 Rear seat 100 Car-mounted acoustic system CF _INIT frequency characteristic (initial transfer function)
CF _SAMP frequency characteristics (transfer function)
CP _INIT phase characteristics (initial transfer function)
CP _SAMP phase characteristics (transfer function)
P _INIT time response characteristics P _SAMP time response characteristics

Claims (9)

A vehicle-mounted acoustic diagnostic apparatus for diagnosing the acoustic characteristics of a vehicle-mounted acoustic system having a plurality of speakers,
One or more microphones corresponding to each of the speakers;
A measurement signal generator for generating a predetermined measurement signal for acoustic characteristic diagnosis;
A switching selection unit that sequentially supplies the measurement signals output from the measurement signal generation unit to a plurality of speakers;
A signal processing unit that collects the measurement sound output from each of the speakers by supplying the measurement signal through the microphone, and calculates a transfer function and a time response characteristic;
A diagnostic unit for performing an acoustic characteristic diagnosis of the in-vehicle acoustic system based on the transfer function calculated by the signal processing unit and a measured time response characteristic;
An on-vehicle acoustic diagnostic apparatus comprising: The in-vehicle acoustic diagnosis apparatus according to claim 1,
An initial characteristic storage unit that stores in advance an initial transfer function that is a transfer function corresponding to each speaker in the initial state of the in-vehicle acoustic system and an initial response characteristic that is a time response characteristic corresponding to each speaker in the initial state; ,
The diagnosis unit performs the acoustic characteristic diagnosis by referring to the initial transfer function and the initial response characteristic for the transfer function calculated by the signal processing unit and the measured time response characteristic.
An on-vehicle acoustic diagnostic apparatus characterized by the above. In the on-vehicle acoustic diagnosis apparatus according to claim 1 or 2,
Based on the transfer function calculated by the signal processing unit and the measured time response characteristic, the diagnosis unit determines whether or not the frequency characteristic, phase characteristic, or time response characteristic variation of each speaker exceeds an allowable range. Discriminate,
When there is a characteristic that exceeds the allowable range, the acoustic characteristic diagnosis that the acoustic characteristic has deteriorated in the in-vehicle acoustic system is performed.
An on-vehicle acoustic diagnostic apparatus characterized by the above. The on-vehicle acoustic diagnostic apparatus according to claim 3,
When the diagnosis unit determines that the variation of the frequency characteristic, the phase characteristic, or the time response characteristic exceeds the allowable range for some of the plurality of speakers, the diagnostic unit exceeds the allowable range. The acoustic characteristic diagnosis that the speaker is deteriorated is performed.
An on-vehicle acoustic diagnostic apparatus characterized by the above. In the on-vehicle acoustic diagnosis apparatus according to claim 3 or 4,
When the diagnosis unit determines that the variation of the frequency characteristic, the phase characteristic, or the time response characteristic exceeds the allowable range for all of the plurality of speakers, a part other than the speaker is included in the in-vehicle acoustic system. Diagnose the acoustic characteristics that it has deteriorated,
An on-vehicle acoustic diagnostic apparatus characterized by the above. In the on-vehicle acoustic diagnostic apparatus according to any one of claims 3 to 5,
An in-vehicle acoustic diagnosis apparatus comprising: a notification unit that notifies the diagnosis unit when the diagnosis unit determines that the acoustic characteristic has been deteriorated. Multiple speakers,
One or more microphones corresponding to each of the speakers;
A measurement signal generator for generating a predetermined measurement signal for acoustic characteristic diagnosis;
A switching selection unit that sequentially supplies the measurement signals output from the measurement signal generation unit to a plurality of speakers;
A signal processing unit that collects the measurement sound output from each of the speakers by supplying the measurement signal through the microphone, and calculates a transfer function and a time response characteristic;
A diagnostic unit for performing acoustic characteristic diagnosis of the in-vehicle acoustic system based on the transfer function calculated by the signal processing unit and the measured time response characteristic;
An in-vehicle acoustic system comprising: A method for controlling an on-vehicle acoustic diagnostic apparatus for diagnosing the acoustic characteristics of an on-vehicle acoustic system having a plurality of speakers,
A measurement signal generation process for generating a predetermined measurement signal for acoustic characteristic diagnosis;
A switching selection process for sequentially supplying the measurement signals individually to a plurality of speakers;
Signal processing that collects measurement sound output from each speaker by supplying the measurement signal via one or a plurality of microphones corresponding to each speaker, and calculates transfer function and time response characteristics Process,
A diagnostic process unit for performing an acoustic characteristic diagnosis of the in-vehicle acoustic system based on the calculated transfer function and the measured time response characteristic;
A control method for an on-vehicle acoustic diagnostic apparatus, comprising: A control program for diagnosing the acoustic characteristics of an on-vehicle acoustic system having a plurality of speakers, and for controlling an on-vehicle acoustic diagnostic apparatus having one or more microphones corresponding to each speaker by a computer,
Generate measurement signals for predetermined acoustic characteristics diagnosis,
The measurement signals are individually supplied to a plurality of speakers sequentially,
When the measurement signal is supplied, the measurement sound output from each speaker is collected via the microphone, and the transfer function is calculated and the time response characteristic is measured.
The acoustic characteristic diagnosis of the in-vehicle acoustic system is performed based on the calculated transfer function and the measured time response characteristic.
A control program characterized by that.

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