JP2019017118A - Failure detection device, audio input/output module, and failure detection method - Google Patents

Abstract

To provide a failure detection device capable of detecting whether or not two microphones are both normal when the two microphones are provided, and an audio input/output module and a failure detection method.SOLUTION: A failure detection device includes an output unit for outputting a confirmation signal from an audio output device, an input unit for inputting an input signal to be input to two microphones provided in an audio input device and to which the confirmation signal output from the audio output device so as to pass around, and a failure detection unit for detecting whether or not both of the two microphones are normal on the basis of a value obtained by summing amplitudes of the input signals input to the two microphones.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a failure detection device, a voice input / output module, and a failure detection method.

2. Description of the Related Art Conventionally, a method of detecting an abnormality such as a device failure in a device that performs an emergency notification or the like is known (for example, Patent Document 1). The emergency information reporting device described in Patent Document 1 emits a predetermined sound signal in an audible band, such as a startup message, from a speaker or the like when the device starts up, notifies the user of the startup and emits a predetermined sound signal. By detecting and analyzing a loopback signal input from a microphone or the like, an abnormality diagnosis of the emergency information reporting device itself is performed.
Such a device may be provided with two microphones. By doing so, it becomes possible to make an emergency report or the like even if one of the microphones breaks down. If two microphones are placed at the same distance from the speaker, the sound input from the two microphones at the same sound pressure level is regarded as the sound emitted from the speaker, and howling is performed by removing the sound. It can also be suppressed.

Japanese Patent No. 3775233

  However, in the emergency information reporting device shown in Patent Document 1, abnormality diagnosis is performed only at the time of activation. For this reason, even if no abnormality is found at the time of activation, if the emergency information reporting device subsequently fails, the emergency information cannot be reported. In addition, when two microphones are provided in the apparatus, even if one of them breaks down, it is possible to make an emergency report or the like, so that the failure may be overlooked. However, it is preferable to detect whether or not both microphones are normal so as to be able to respond early when a microphone is out of order in order to reliably report an emergency or the like.

  The present invention has been made in view of such circumstances, and the purpose of the present invention is to detect whether or not both microphones are normal when the device is provided with two microphones. An apparatus, a voice input / output module, and a failure detection method are provided.

  In order to solve the above-described problem, a failure detection apparatus according to the present invention includes an output unit that outputs a confirmation signal from an audio output device, and an input signal that is input to two microphones included in the audio input device. Based on the input unit that acquires the input signal that is input by the check signal output from the output device wrapping around, and the sum of the amplitudes of the input signals input to the two microphones, the two microphones A failure detection unit that detects whether or not both are normal.

  In the failure detection method of the present invention, the output unit outputs a confirmation signal from the audio output device, and the input unit is an input signal input to two microphones included in the audio input device, and the audio output device An input signal that is input by wrapping around the confirmation signal output from the two microphones is acquired, and the failure detection unit, based on the sum of the amplitudes of the input signals input to the two microphones, Detect whether both are normal.

  As described above, according to the present invention, when two microphones are provided in the apparatus, it is possible to detect whether both microphones are normal.

It is a functional block diagram which shows the structural example of the emergency call module by embodiment of this invention. It is a figure which shows the example of an external appearance of the audio | voice input / output module by embodiment of this invention. It is a functional block diagram which shows the structural example of a failure detection apparatus. It is a figure for demonstrating a confirmation signal. It is a figure for demonstrating the relationship between an input signal and noise. It is a figure for demonstrating a failure detection signal. It is a flowchart which shows an example of the failure detection process which a failure detection apparatus performs.

Hereinafter, a failure detection apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram showing a configuration example of an emergency call module using a failure detection apparatus according to an embodiment of the present invention. The emergency call module 100 is mounted in a passenger compartment of a vehicle, for example, and makes an emergency call in the event of an emergency such as an accident. In the present embodiment, the emergency call module 100 includes a communication module 90 and a voice input / output module 80.
The communication module 90 includes a wireless transmission / reception device (not shown), and communicates with an emergency center or the like via the wireless transmission / reception device. The communication module 90 inputs a transmission sound signal such as an emergency call from the user output from the voice input / output module 80 and transmits the transmission sound signal to an emergency center or the like. The communication module 90 receives a received sound signal such as a response to an emergency call output from an emergency center or the like, and outputs the received sound signal to the voice input / output module 80.
The communication module 90 receives the failure detection signal output from the voice input / output module 80 and transmits the failure detection signal to an emergency center or the like.

The voice input / output module 80 includes a voice output device 50, a voice input device 60, and a processor 70. The audio output device 50 includes a DAC (Digital Analog Converter), an amplifier (amplifier), and a speaker. The voice input device 60 includes microphones 61 and 62, an amplifier, and an analog-digital converter (ADC). The processor 70 includes each of the failure detection device 10, the sound processing unit 20, the signal generation unit 30, and the addition unit 40.
Each of the failure detection device 10, the audio processing unit 20, the signal generation unit 30, and the addition unit 40 is, for example, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or a processor combining these, and a program memory This is realized by executing a program (software) stored in the. Some or all of the functions executed by these programs are realized by analog control circuits, or hardware such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field Scale Integration), etc. Alternatively, it may be realized by cooperation of software and hardware.

The failure detection apparatus 10 outputs a control signal to cause the signal generation unit 30 to generate a confirmation signal composed of a frequency other than the audible band. The confirmation signal is emitted (output) as a sound from the sound output device 50 via the adder 40. Further, the output confirmation signal wraps around the voice input device 60 through a space such as the passenger compartment, and is collected (input) into the voice input device 60 as an input signal.
The failure detection device 10 receives an input signal from the voice input device 60. Moreover, the failure detection apparatus 10 detects whether the audio | voice output apparatus 50 and the audio | voice input apparatus 60 are normal based on a confirmation signal and an input signal.

  The audio processing unit 20 inputs the reception sound signal from the communication module 90 and outputs the reception sound signal to the audio output device 50 via the addition unit 40. The voice processing unit 20 inputs an input signal from the voice input device 60, performs voice processing on the input signal, and outputs the input signal (transmission sound signal) after the voice processing to the communication module 90.

  The signal generation unit 30 generates a signal having a predetermined frequency according to the control signal from the failure detection apparatus 10. The signal generator 30 uses, for example, a pulse generator or DTMF (Dual Tone Multi-Frequency) in order to generate a signal having a predetermined frequency. When using DTMF, for example, the signal generation unit 30 causes the DTMF to generate predetermined eight types of frequencies (tone signals) between 697 to 1633 [Hz], and the following equations (1) and (2): A signal having a predetermined frequency can be generated by performing signal processing on the tone signal using the double angle formula shown in FIG. Here, x represents an arbitrary angle.

Cos (2x) = 1−2 × {Sin (x)} ² (1)
Sin (3x) = 3 × Sin (x) −4 × {Sin (x)} ³ (2)

  For example, the signal generation unit 30 causes the DTMF to generate a tone signal of 697 [Hz] based on the above formula (2), and from the signal obtained by multiplying the tone signal by 3 times, the signal obtained by squaring the tone signal to 4 times is obtained. By subtracting, a signal having a frequency of 2091 [Hz] that is a frequency other than the audible band can be generated.

  The signal generation unit 30 adjusts the signal level of the generated signal having a predetermined frequency in accordance with the control signal from the failure detection apparatus 10, and generates a confirmation signal.

  The adder 40 adds the received sound signal from the audio processor 20 and the confirmation signal from the signal generator 30 and outputs the added signal to the audio output device 50.

  The audio output device 50 converts the digital signal from the adder 40 into an analog signal using a DAC, and outputs the converted analog signal to the speaker 51 via a buffer such as an amplifier. The speaker 51 converts an electrical signal from the amplifier into physical vibration and outputs the physical vibration to the outside.

  The audio input device 60 converts the vibration amplitude of the external sound or the sound output from the audio output device 50 into an analog electric signal by the microphones 61 and 62, and converts the converted analog electric signal into a digital signal by the ADC. The digital signal is output to the failure detection device 10 and the sound processing unit 20.

FIG. 2 is a diagram illustrating an external appearance example of the voice input / output module 80. In the example shown in FIG. 2, the speaker 51 is installed at the center of one main surface of the housing 200. In addition, a microphone 61 is installed on one of the adjacent top portions of one main surface of the housing 200, and a microphone 62 is installed on the other side so that the distances from the speaker 51 are equal to each other. By setting the distances to be equal to each other in this way, the confirmation signal output from the speaker 51 can be input to the microphones 61 and 62 at substantially the same sound pressure level.
As shown in FIG. 2, the confirmation signal output from the speaker 51 goes around the microphones 61 and 62 and is input from the microphones 61 and 62. The failure detection apparatus 10 is configured so that the sound pressure at the microphones 61 and 62 when the confirmation signal is input to the microphones 61 and 62 is 70 [dB SPL (Sound Pressure Level)] on average, for example. The signal generator 30 adjusts the signal level of the confirmation signal.
For example, when such a voice input / output module 80 is mounted in a passenger compartment of a vehicle, the voice input / output module 80 may be attached at any position on the ceiling side between the driver seat and the passenger seat. In this case, since the confirmation signal output from the speaker 51 is emitted toward the driver and the passenger on the passenger seat, it can be made difficult for the driver and the passenger to enter the ear.
The audio processing performed by the audio processing unit 20 includes processing for preventing howling and the like included in the input signal. Howling occurs when the sound output from the audio output device 50 wraps around the audio input device 60 and is input from the audio input device 60 together with external sound. In the present embodiment, the microphone 61 and the microphone 62 are installed so that the distance from the speaker 51 is equal to each other, and the sound output from the speaker 51 including the confirmation signal component wraps around the speaker 51 and is input. Is equivalent to the microphone 61 and the microphone 62. Therefore, the audio processing unit 20 subtracts the input signal from the one input signal from the input signal from the microphone 61 of the audio input device 60 and the input signal from the microphone 62, thereby obtaining a confirmation signal component. The sound output from the included voice output device 50 wraps around the voice input device 60 to remove the input sound, and howling can be prevented. The voice processing unit 20 can prevent a reduction in voice quality of the transmission sound signal by preventing howling.

  FIG. 3 is a diagram illustrating a configuration example of the failure detection apparatus 10. The failure detection apparatus 10 includes a timer 11, an output unit 12, an input unit 13, and a failure detection unit 15. For example, the failure detection apparatus 10 receives a failure detection timing signal output from the timer 11 at an arbitrary timing, performs failure detection processing, and outputs a detection result as a failure detection signal. The arbitrary timing referred to here may be any timing after the startup, for example, a timing of a periodic time after the startup. Thus, since the failure detection process can be performed at an arbitrary timing, the failure detection process can be performed even at the time other than the startup.

  The output unit 12 causes the signal generation unit to generate a confirmation signal composed of a frequency other than the audible band. Here, the audible band is a frequency band that a person can feel as sound due to tympanic membrane vibration or the like, and generally refers to a frequency band of about 20 [Hz] to 20 [kHz]. However, individual differences and age differences are large in whether or not they are felt as sounds. In this embodiment, the confirmation signal configured with a frequency other than the audible band is a signal configured with a frequency that is generally difficult to be recognized by human hearing. May include a signal composed of an audible band frequency.

Here, the frequency of the confirmation signal will be described. The confirmation signal may be a signal having a frequency higher than about 20 [kHz], but may be a frequency that can be output from the audio output device 50 and a frequency that can be input from the audio input device 60. preferable.
An output device such as a speaker and an input device such as a microphone are devices that generally output and input a sound signal in an audible band. For this reason, it is only necessary to represent a signal up to about 20 [kHz], and the sampling frequency generally processed by these devices is about 48 [kHz] or a multiple of 96 [kHz] or about 192 [kHz]. There are many cases.
Further, it is generally known that a signal having a lower frequency (longer wavelength) is easier to wrap around, and a signal having a higher frequency (smaller wavelength) is more difficult to wrap around because the straightness of the signal is higher. In the present embodiment, in order for the confirmation signal to enter and be input to the voice input device 60, it is preferable that the frequency is not so high (eg, 100 [kHz] or less).
In the present embodiment, the confirmation signal is preferably a signal without signal distortion. In order not to cause signal distortion in the confirmation signal, it is desirable to perform a process of generating the confirmation signal at a sampling frequency that is about four times the frequency of the confirmation signal. By suppressing the signal distortion in the confirmation signal output from the audio output device 50, it is possible to reduce the output of an audible band signal due to the signal distortion.
From the viewpoint as described above, it is desirable that the confirmation signal is configured with a frequency that can be input / output by a general-purpose audio input / output device, is easily circulated moderately, and has little distortion. In the failure detection apparatus of the present embodiment, the confirmation signal is configured with a frequency of 16 to 24 [kHz].

  FIG. 4 is a diagram for explaining the confirmation signal. FIG. 4A is a diagram illustrating an example of the confirmation signal. FIG. 4B is an enlarged view of a part of the confirmation signal. In FIG. 4A, the vertical axis represents signal amplitude and the horizontal axis represents time.

As shown in FIG. 4A, the confirmation signal is, for example, a burst signal. By making the confirmation signal a burst signal, the confirmation signal is also received when noise having a frequency constituting the confirmation signal existing in the natural world is mixed when the confirmation signal wraps around and is input to the voice input device 60. Can be easily distinguished by the failure detection unit 15. The failure detection process performed by the failure detection unit 15 will be described in detail later.
In the example of FIG. 4A, the lengths of the section A1 and the section A2 are equal, and the signaled section (section A1, for example, 0.5 seconds) for the period (section A that combines the section A1 and section A2, for example, 1 second). Second) (duty ratio) is about 50%. When the confirmation signal is a burst signal, the burst period and the duty ratio may be arbitrary. The failure detection apparatus 10 according to the present embodiment artificially sets the burst period and duty ratio of the confirmation signal, thereby making it easy to distinguish the confirmation signal from noise existing in the natural world and performing failure detection more accurately. Can do.
Here, the failure detection apparatus 10 determines that the input signal from the voice input device 60 is normal when the duty ratio of the input signal is within a predetermined range. The predetermined range here can be set arbitrarily, but for example, the duty ratio set when generating the confirmation signal may be set in consideration of the case where noise that may exist in the natural world is included. Good. By doing so, it is possible to reduce misjudgment due to the presence of noise.

  In FIG. 4A, the confirmation signal envelope gradually increases during the section A1, and the confirmation signal envelope gradually decreases during the section A2. That is, the confirmation signal is adjusted and output so as to suppress an abrupt change in the envelope. An abrupt change in the envelope can distort the signal waveform and cause noise due to signal distortion. The failure detection apparatus 10 of the present embodiment adjusts the pulse width of the confirmation signal so that the envelope of the burst signal gradually changes, so that signal distortion caused by switching between the signaled section and the non-signal section is audible. The generation of noise can be suppressed.

  Further, in FIG. 4A, a threshold is set for the signal amplitude. 4A shows that a section having an amplitude equal to or greater than a predetermined threshold is section C with respect to section A corresponding to the burst period of the confirmation signal.

  Returning to FIG. 3, the input unit 13 inputs the input signal from the voice input device 60 and outputs the input signal to the failure detection unit 15. The input signal includes a confirmation signal that wraps around the voice input device 60. The input unit 13 may pass the bandpass filter to the input signal and output the signal after passing through the bandpass filter to the failure detection unit 15. In this case, the bandpass filter has a characteristic that blocks a signal having a frequency different from the frequency of the confirmation signal. The failure detection apparatus 10 can perform band-pass filter processing for extracting a signal having a frequency of the confirmation signal from the input signal in order to specify the frequency of the confirmation signal when the signal generation unit 30 generates the signal. . By using the input signal that has passed through the band-pass filter for the failure detection process, the failure detection apparatus 10 can detect the failure more accurately.

The failure detection unit 15 detects whether or not at least one of the audio output device 50 and the audio input device 60 is normal based on the confirmation signal and the input signal. The failure detection unit 15 includes an amplitude comparison unit 17 and a determination unit 16.
The amplitude comparison unit 17 compares the amplitude of the input signal with a predetermined threshold value. The amplitude comparison unit 17 notifies the determination unit 16 of the comparison result.
The determination unit 16 receives the comparison result from the amplitude comparison unit 17 and holds the comparison result within a predetermined time, and the ratio of the time when the input signal with respect to the burst period is equal to or greater than the threshold value (the interval in FIG. 4A). A ratio of section C to A, hereinafter referred to as section ratio).
The determination unit 16 determines that the voice output device 50 and the voice input device 60 are normal based on the obtained section ratio when the section ratio is within a predetermined range. Further, the determination unit 16 determines that one of the audio output device 50 and the audio input device 60 is not normal when the section ratio is outside a predetermined range.
The determination unit 16 outputs the determination result as a failure detection signal.

The failure detection unit 15 may perform failure detection on an input signal obtained by adding signals input from both the microphones 61 and 62 of the voice input device 60, and a signal input from each of the microphones 61 and 62. Failure detection may be performed for each.
When performing failure detection on the combined input signals, for example, the failure detection unit 15 has the signal amplitude of the combined input signals equal to or greater than a threshold value, and the input signals are normally input from the voice input device 60 and added together. When it corresponds to the value of the signal amplitude of the input signal, it can be determined that the input signal is input from both the microphones 61 and 62. On the other hand, when the signal amplitude of the summed input signal is equal to or greater than the threshold value, but the input signals are normally input from the microphones 61 and 62 and do not correspond to the value of the summed signal amplitude of the input signal, the microphone It can be determined that the input signal is normally input from either one of 61 and 62 and is not normally input from the other.
When performing failure detection, for example, the failure detection unit 15 first inputs a signal from the microphone 61 to the input unit 13 and performs failure detection. Next, the failure detection unit 15 inputs a signal from the microphone 62 to the input unit 13 and performs failure detection. By doing so, the failure detection unit 15 can detect whether each of the microphones 61 and 62 is normal. For example, when either one of the microphones 61 or 62 is not normal, it is determined that there is a minor failure, and when both the microphones 61 and 62 are not normal, it is determined that there is a major failure. A failure detection signal including information representing the above may be output.

  FIG. 5 is a diagram for explaining the relationship between an input signal and noise. FIG. 5A is a diagram illustrating an example of a waveform of noise existing in the environment and having a frequency close to the frequency constituting the confirmation signal. For example, it is a waveform of noise generated when a metal object such as a metal key holder hits another metal object. FIG. 5B is a diagram illustrating an example of the waveform of the input signal. Even when an input signal that has passed through a band-pass filter is used for failure detection processing, noise having a frequency close to the frequency that constitutes the confirmation signal cannot be removed. For this reason, a confirmation signal and noise may be mixed in the input signal. Even in such a case, the burst period of the confirmation signal is set to be distinguishable from the noise generation duration (for example, the burst period is set to be longer than the noise generation duration), and is included in the input signal. The presence or absence of the confirmation signal can be determined more accurately.

  FIG. 6 is a diagram for explaining a failure detection signal. In FIG. 6, the vertical axis indicates the signal level, and the horizontal axis indicates time. The upper part of FIG. 6 shows the output waveform of the failure detection signal, and the second stage of FIG. 6 shows the time when the failure detection process was performed. In the example of FIG. 6, a case where the failure detection process is periodically performed with a period T is shown. The failure detection unit 15 performs failure detection at a period T, and inverts the failure detection signal when it is determined that both the audio output device 50 and the audio input device 60 are normal. In the example of FIG. 6, failure detection processing is performed at each of the times TS1 to TS3, and it is determined that both the audio output device 50 and the audio input device 60 are normal at each of the times T1 to T3. Yes. At each of the times T1 to T3, the failure detection signal is inverted and output from the low level to the high level or from the high level to the low level.

In the example of FIG. 6, the failure detection process is performed at time TS4. However, at time T4, it is determined that at least one of the audio output device 50 and the audio input device 60 is not normal. The failure detection signal (high level) at time T3 is output as it is without being inverted.
Thus, in this embodiment, the failure detection signal is not inverted when the voice input / output module 80 is not operating normally. That is, when the failure detection signal is inverted (changed), it can be shown that at least the voice input / output module 80 including the failure detection device 10 is operating normally. Further, the failure detection device 10 according to the present embodiment outputs a failure detection signal as a toggle signal, so that not only whether the audio output device 50 and the audio input device 60 are normal, but also the processor 70 itself is normal. The communication module 90 can be notified of whether or not there is.

  The failure detection signal may be output using a plurality of communication paths. Thereby, even when some communication paths cannot communicate, a failure detection signal can be notified to the communication module 90 through other communication paths, and a robust configuration can be achieved. For example, the communication path may use a plurality of physical signal sources. The communication path is a communication path for outputting a failure detection signal from the failure detection device 10, a failure detection result is output from the failure detection device 10 to the voice processing unit 20, and the communication module 90 is notified from the voice processing unit 20. All or some of the signal lines that output the transmission sound signal may be used. Then, the failure detection result may be output using both the communication path notified from the voice processing unit 20 to the communication module 90 and the communication path for outputting the failure detection signal from the failure detection apparatus 10. When outputting a failure detection result from a signal line that outputs a transmission sound signal, if a configuration in which a failure detection signal is notified only when the audio output device 50 or the like is not normal, more reliable communication without increasing the number of signal lines The module 90 can be notified of a device failure.

  FIG. 7 is a flowchart illustrating an example of the failure detection process. As shown in FIG. 7, when the failure detection timing signal from the timer 11 is input, the failure detection unit 15 outputs a control signal to the signal generation unit 30 to output a confirmation signal (step S1). The confirmation signal is output from the audio output device 50 via the adder 40, wraps around the microphones 61 and 62, and is input from the audio input device 60. The failure detection unit 15 inputs an input signal from the voice input device 60 (step S2). The failure detection unit 15 identifies a section based on the burst period of the confirmation signal among the input signals, and determines the amplitude of the input signal and a predetermined threshold value for the input signal within the predetermined section. Are compared (step S3). The failure detection unit 15 obtains a ratio (section ratio) between a predetermined section and a section having an amplitude equal to or greater than a predetermined threshold value in the specified predetermined section, and whether the section ratio is within a predetermined range. Whether or not is determined (step S4). The failure detection unit 15 determines that the voice output device 50 and the voice input device 60 are normal if the section ratio is within a predetermined range (step S5). When the failure detection unit 15 determines that the failure is normal, the failure detection unit 15 inverts the signal level of the failure detection signal (step S6). On the other hand, if the section ratio is outside the predetermined range, the failure detection unit 15 determines that at least one of the audio output device 50 and the audio input device 60 is not normal (step S7). If the failure detection unit 15 determines that the failure is not normal, the failure detection unit 15 does not invert the signal level of the failure detection signal. As a result, the failure detection signal becomes a high level or low level signal (step S8).

  As described above, the failure detection apparatus 10 of the present embodiment outputs the confirmation signal composed of a frequency other than the audible band from the audio output apparatus 50 and the input signal from the audio input apparatus 60. Failure detection by including an input unit 13 to receive and a failure detection unit 15 that detects whether both the audio output device 50 and the audio input device 60 are normal based on the confirmation signal and the input signal. In this case, failure detection can be performed without generating a sound having a frequency in the audible band.

The failure detection apparatus 10 of the present embodiment is not limited to the configuration described so far, and may be configured such that, for example, the frequency constituting the confirmation signal can be changed in order to perform failure detection more accurately.
In the present embodiment, the frequency that constitutes the confirmation signal only needs to be configured so that at least the frequency of the confirmation signal is outside the audible band. For example, the failure detection apparatus 10 sets the frequency of the confirmation signal to 19 [kHz], 20 You may output the confirmation signal which changed the frequency according to progress of time so that a fixed area may be output in order of [kHz] and 21 [kHz].

  In this case, failure detection is performed at the input unit 13 of the failure detection apparatus 10 via three types of band-pass filters that block other than the respective frequencies. First, the failure detection unit 15 detects a signal in which a section ratio of an input signal through a bandpass filter that passes 19 [kHz] is within a predetermined range, and passes 20 [kHz] and 21 [kHz]. It is determined whether or not a signal is detected in which the section ratio of the input signal through the band-pass filter does not fall within a predetermined range. Next, the failure detection unit 15 detects a signal in which the section ratio of the input signal through the band pass filter that passes 20 [kHz] is within a predetermined range, and sets 19 [kHz] and 21 [kHz]. It is determined whether or not a signal that does not fall within a predetermined range of the interval ratio of the input signal through the bandpass filter that is passed is detected. Furthermore, the failure detection unit 15 detects a signal whose section ratio of the input signal through the band-pass filter that passes 21 [kHz] is within a predetermined range, and passes 19 [kHz] and 20 [kHz]. It is determined whether or not a signal is detected in which the section ratio of the input signal through the band-pass filter does not fall within a predetermined range. If a signal having a section ratio within a predetermined range is detected in the order of 19 [kHz], 20 [kHz], and 21 [kHz] from the input signal, the failure detection unit 15 determines that the signal is normal. May be. Thus, failure detection can be performed more accurately by changing the frequency of the confirmation signal.

Further, in this embodiment, the output level of the confirmation signal is constant, but the present invention is not limited to this. For example, a pattern in which the output level of the confirmation signal is output at three levels of large, medium, and small may be repeated. The failure detection unit 15 includes, for example, an input signal and a plurality of threshold values (here, threshold value 1, threshold value 2 smaller than threshold value 1, and threshold value 3 smaller than threshold value 2). 3).
In this case, first, the failure detection unit 15 confirms that a signal in which the section ratio of signals larger than the threshold value 1 is within a predetermined range is detected. Next, the failure detection unit 15 detects a signal in which the section ratio of signals greater than the threshold value 1 is not within a predetermined range, and the section ratio of signals greater than the threshold value 2 is in a predetermined range. Confirm that the signal is detected. Further, the failure detection unit 15 detects a signal in which the section ratio of the signal greater than the threshold value 2 is not within the predetermined range, and the signal in which the section ratio of the signal greater than the threshold value 1 is within the predetermined range. Confirm that is detected. If signals are detected in the order described above, the failure detection unit 15 may determine that the signals are normal.

  Further, the failure detection unit may detect a frequency or the like included in noise before performing failure detection. By detecting the state of noise before failure detection, failure detection can be performed more accurately. For example, when the same frequency as the frequency of the confirmation signal used for failure detection is included in a certain level or more, failure detection is not performed until the level of the same frequency as the frequency of the confirmation signal used for failure detection included in noise is lowered. Alternatively, the frequency of the confirmation signal may be changed so that the frequency included in the noise and the frequency of the confirmation signal do not overlap.

DESCRIPTION OF SYMBOLS 10 Failure detection apparatus 20 Audio | voice processing part 30 Signal generation part 40 Addition part 50 Audio | voice output apparatus 51 Speaker 60 Audio | voice input apparatus 61,62 Microphone 70 Processor 80 Voice input / output module 90 Communication module 100 Emergency call module 200 Case

Claims (10)

An output unit for outputting a confirmation signal from the audio output device;
An input signal that is input to two microphones included in the voice input device, and an input unit that acquires an input signal that is input by wrapping around the confirmation signal output from the voice output device;
A failure detection unit that detects whether or not both of the two microphones are normal based on a sum of amplitudes of the input signals input to the two microphones;
A failure detection apparatus comprising: The failure detection unit is an average in which a value obtained by adding the amplitudes of the input signals input to the two microphones is adjusted in advance as an average sound pressure level when the input signal is input to the voice input device. When the sound pressure level corresponds to a normal sound pressure level that is a sum of sound pressure levels, it is determined that both of the two microphones are normal.
The failure detection apparatus according to claim 1. The failure detection unit detects whether one of the two microphones is not normal;
The failure detection device according to claim 1 or 2. The failure detection unit is an average in which a value obtained by adding the amplitudes of the input signals input to the two microphones is adjusted in advance as an average sound pressure level when the input signal is input to the voice input device. If it does not correspond to the normal sound pressure level that is the sum of the sound pressure levels, it is determined that one of the two microphones is not normal,
The failure detection apparatus according to claim 3. The failure detection unit outputs a failure detection signal indicating a result of determining whether or not the two microphones are normal. When the failure detection unit determines that both of the two microphones are normal, When it is determined that one of them is not normal, the failure detection signals having different values are output.
The failure detection device according to any one of claims 1 to 4. The confirmation signal is a signal composed of a frequency other than the audible band.
The failure detection apparatus according to any one of claims 1 to 5. The confirmation signal is a burst signal;
The failure detection apparatus according to any one of claims 1 to 6. The two microphones are installed such that the distances from the speakers included in the audio output device are equal to each other.
The failure detection apparatus according to any one of claims 1 to 7. The failure detection device according to any one of claims 1 to 8,
The audio output device;
The voice input device;
Voice input / output module with The output unit outputs a confirmation signal from the audio output device,
The input unit is an input signal that is input to two microphones included in the voice input device, and obtains an input signal that is input by wrapping around the confirmation signal output from the voice output device,
The failure detection unit detects whether or not both of the two microphones are normal based on a value obtained by adding the amplitudes of the input signals input to the two microphones.
Fault detection method.

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