JP2020086852A - Recording device for vehicle, signal processing device, and signal recording method - Google Patents

Abstract

To provide a technique for enabling an unnecessary sound signal to be removed easily and accurately from a signal concerning a sound occurred in or around a vehicle and recorded in a recording medium.SOLUTION: A recording device for a vehicle includes: a sound source signal acquisition unit that acquires a sound source signal supplied to a speaker mounted on the vehicle; a sound collection signal acquisition unit that acquires a sound collection signal collected by a microphone mounted on the vehicle; and a recording control unit that records the sound source signal and the sound collection signal in the recording medium.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle recording device, a signal processing device, and a signal recording method.

A drive recorder, which is a recording device for a vehicle, records a sound generated inside or around the vehicle and an image showing the inside or the periphery of the vehicle on a recording medium by using a microphone mounted on the vehicle and a camera. You can

The drive recorder records not only sounds emitted by an occupant in the passenger compartment and sounds when the vehicle comes into contact, but also other sounds. For example, voice such as music flowing in the vehicle compartment is also recorded on the recording medium by the drive recorder. Patent Document 1 describes a noise/audio sound canceling device that removes an audio signal emitted from a speaker in a vehicle interior from a sound signal in the vehicle interior detected by a microphone.

JP, 2001-22380, A

However, the noise/audio sound canceling device described in Patent Document 1 has a problem that the audio sound cannot be canceled sufficiently because the audio sound canceling process is performed in real time.

The present invention has been made in view of the above problems, and it is possible to easily and accurately remove an unnecessary audio signal from a signal relating to audio that is generated inside or around the vehicle and is recorded in a recording medium. The purpose is to provide the technology to do so.

A vehicle recording apparatus according to the present invention is a vehicle recording apparatus for recording a signal related to a sound generated inside or around a vehicle in a recording medium, and obtains a sound source signal supplied to a speaker mounted on the vehicle. A sound source signal acquisition unit, a sound collection signal acquisition unit that acquires a sound collection signal collected by a microphone mounted on the vehicle, and a recording control unit that records the sound source signal and the sound collection signal in the recording medium. And a configuration (first configuration).

In the vehicle recording device having the first configuration, the signal processing unit that uses the sound source signal and the sound collection signal to remove a sound signal emitted from the speaker included in the sound collection signal. May be provided (second configuration).

In the vehicle recording device having the second configuration, the signal processing unit transmits sound between the speaker and the microphone based on a predetermined audio signal that is supplied to the speaker and collected by the microphone. A configuration (third configuration) in which a function is derived and the sound signal emitted from the speaker included in the sound collection signal is removed using the acoustic transfer function may be used.

Further, a signal processing device according to the present invention is a signal processing device for processing a signal relating to a sound generated inside or around a vehicle, and a sound source signal supplied to a speaker mounted on the vehicle and a signal to the vehicle. A configuration (fourth configuration) including a signal processing unit that removes a sound signal emitted from the speaker included in the sound collection signal by using a sound collection signal collected by the mounted microphone. May be.

Further, in the signal processing device having the fourth configuration, the signal processing unit is provided between the speaker and the microphone, which is derived in advance based on a predetermined audio signal supplied to the speaker and collected by the microphone. A configuration (fifth configuration) in which the sound signal emitted from the speaker included in the sound collection signal is removed using the acoustic transfer function of (5) may be used.

Further, a signal recording method according to the present invention is a signal recording method for recording a signal related to a sound generated inside or around a vehicle in a recording medium, and obtains a sound source signal supplied to a speaker mounted on the vehicle. And a step of acquiring a sound collection signal collected by a microphone mounted on the vehicle, and a step of recording the sound source signal and the sound collection signal in the recording medium (the sixth embodiment). Configuration).

According to the configuration of the present invention, the sound source signal supplied to the speaker mounted on the vehicle and the sound collection signal collected by the microphone mounted on the vehicle can be recorded on the recording medium. Since the raw sound source signal before being output from the speaker is recorded, by performing advanced analysis processing after recording the audio signal, the speaker included in the sound collection signal can be compared to the case where analysis processing is performed in real time. It is possible to easily and accurately remove the audio signal emitted from the. That is, it becomes possible to easily and accurately remove an unnecessary audio signal from a signal relating to the audio generated inside or around the vehicle and recorded on the recording medium.

Block diagram showing the configuration of the vehicle recording apparatus of the first embodiment 1 is an external perspective view of a vehicle equipped with the vehicle recording apparatus of the first embodiment. Flowchart showing an example of signal recording processing of the vehicle recording device Block diagram showing the configuration of a vehicle recording apparatus of a modification FIG. 3 is a diagram for explaining a first example of signal processing in a vehicle recording device. FIG. 3 is a diagram for explaining a second example of signal processing in the vehicle recording device. Block diagram showing the configuration of the signal processing device of the second embodiment.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents of the embodiments described below.

<1. First Embodiment>
<1-1. Overview of vehicle recorders>
FIG. 1 is a block diagram showing the configuration of a vehicular recording apparatus 1 of the first embodiment. The vehicular recording apparatus 1 is, for example, a drive recorder, and is mounted on the vehicle-mounted apparatus 2 mounted on the vehicle. The in-vehicle device 2 is, for example, a navigation device, and is a device that guides a travel route from a departure place to a destination. That is, the navigation device of the vehicle-mounted device 2 has the function of a drive recorder by mounting the vehicle recording device 1.

FIG. 2 is an external perspective view of a vehicle 3 in which the vehicle recording apparatus 1 according to the first embodiment is mounted. As described above, the vehicle recording device 1 is included in the vehicle-mounted device 2 shown in FIG. A camera 4, a speaker 5, and a microphone 6 mounted on the vehicle are connected to the vehicle-mounted device 2.

The camera 4 includes an image sensor such as an image sensor and an optical system such as a lens, and can electronically acquire image data. In the present embodiment, the camera 4 is arranged near the upper part of the windshield while facing the front of the vehicle 3. The number and arrangement of the cameras 4 may be changed appropriately. For example, a front camera that captures the front of the vehicle 3 and a back camera that captures the rear of the vehicle 3 may be provided.

The speaker 5 is a device that converts the supplied sound source signal into sound and outputs the sound, and faces the vehicle interior. The number and arrangement of the speakers 5 may be changed appropriately. The vehicle-mounted device 2 can inform, for example, a map, road information, the position of the vehicle 3 and the like from the speaker 5 in the vehicle interior by voice. The in-vehicle device 2 may be equipped with an audio device, for example. In addition to the vehicle-mounted device 2, an audio device or the like may be mounted on the vehicle 3. Thereby, for example, music can be played from the speaker 5 into the passenger compartment.

The microphone 6 is a device that collects sound generated inside or around the vehicle and converts it into a collected signal. The number and arrangement of the microphones 6 may be changed appropriately. For example, an external microphone that collects sounds generated outside the vehicle 3 and an in-vehicle microphone that collects sounds generated inside the vehicle 3 may be provided.

The vehicle-mounted device 2 includes, for example, a control unit (not shown) that controls the entire vehicle-mounted device 2 and a display unit (not shown) that displays an image showing a map, road information, the position of the vehicle 3, and the like, a captured image of the camera 4, and the like. ) And an operation unit (not shown) that receives an operation performed by the occupant on the vehicle-mounted apparatus 2. The vehicle-mounted device 2 further includes a sensor unit 21, a position information acquisition unit 22, and a recording medium mounting unit 23. The control unit of the vehicle-mounted device 2 sends and receives various information and data to and from these constituent elements.

The sensor unit 21 includes various sensors for detecting the state of the vehicle 3, such as an acceleration sensor and a vehicle speed sensor. The acceleration sensor detects acceleration indicating the magnitude of impact applied to the vehicle 3. The acceleration detected by the acceleration sensor has, for example, a magnitude in each of three axes or two axes orthogonal to each other. The vehicle speed sensor detects the traveling speed (vehicle speed) of the vehicle 3. The vehicle recording device 1 can acquire vehicle state information such as acceleration information and vehicle speed information regarding the vehicle 3 detected by the sensor unit 21.

The position information acquisition unit 22 acquires position information indicating the current position of the vehicle-mounted device 2. As the position information acquisition unit 22, for example, a GPS receiving device that receives a GPS (Global Positioning System) signal and generates position information can be used. The position information includes, for example, latitude information and longitude information. The vehicular recording apparatus 1 can acquire the position information generated by the position information acquisition unit 22.

The recording medium mounting unit 23 is configured so that the recording medium 7 can be attached and detached. The recording medium 7 is, for example, a memory card, and the recording medium mounting portion 23 in this case is configured as a card slot. The recording medium 7 may be, for example, a magnetic disk, an optical disk, a magneto-optical disk, or the like. In the present embodiment, it is assumed that the recording medium 7 is mounted in the recording medium mounting portion 23, and data can be freely written and read from the recording medium 7. The recording medium 7 may be a recording medium that is built in the vehicle-mounted device 2 in a non-removable manner.

<1-2. Configuration of vehicle recording device>
The vehicle recording device 1 is a device that records a signal relating to a sound generated inside or around the vehicle on a recording medium 7. The vehicle recording device 1 is configured to include a control unit 11 and a storage unit 12.

The control unit 11 is a so-called microcomputer including a CPU (Central Processing Unit), a RAM (Random Access Memory), and a ROM (Read Only Memory), which are not shown. The control unit 11 processes and transmits/receives information based on the program stored in the storage unit 12. The control unit 11 is connected to the storage unit 12, the camera 4, the speaker 5, the microphone 6, the sensor unit 21, the position information acquisition unit 22, and the recording medium mounting unit 23. The control unit 11 sends and receives various information and data to and from these constituent elements.

The control unit 11 includes a sound source signal acquisition unit 111, a sound collection signal acquisition unit 112, a clock unit 113, and a recording control unit 114. The functions of the respective constituent elements of the control unit 11 are realized by the CPU performing arithmetic processing according to a program.

The sound source signal acquisition unit 111 acquires a sound source signal related to the sound supplied to the speaker 5. This sound source signal is a signal related to the sound (sound source) before being output from the speaker 5 toward the vehicle interior. For example, the sound source signal includes a route guidance voice in the navigation function of the vehicle-mounted apparatus 2. Further, for example, the sound source signal includes a voice such as music output from an audio device or the like mounted on the vehicle 3.

The sound collection signal acquisition unit 112 acquires a sound collection signal relating to a sound generated by the microphone 6 inside or around the vehicle. For example, the sound collection signal includes the voice of the occupant emitted in the vehicle compartment. Further, for example, the sound collection signal includes the sound when the vehicle comes into contact with the sound collection signal. Further, for example, the sound collection signal includes a sound output from the speaker 5 toward the vehicle interior.

In addition, the control unit 11 further acquires a captured image captured by the camera 4, vehicle state information acquired by the sensor unit 21, and position information generated by the position information acquisition unit 22. (Not shown).

The clock unit 113 acquires time information indicating the current date and time and time. The time counting unit 113 has an internal battery and can operate without receiving power supply from the outside. Note that the time information may be acquired from the GPS receiving device used as the position information acquiring unit 22 instead of the time counting unit 113.

The recording control unit 114 performs recording control for recording the audio signals sequentially acquired by the sound source signal acquisition unit 111 and the collected sound signal acquisition unit 112 on the recording medium 7. Further, the recording control unit 114 performs recording control for recording the captured image, the vehicle state information, and the position information acquired by the data acquisition unit (not shown) on the recording medium 7. The data recorded on the recording medium 7 at a certain time includes, for example, the audio signal, the captured image, the vehicle state information, and the position information acquired at that time. At this time, the audio signal, the captured image, the vehicle state information, and the position information acquired at the common time are associated with each other. The recording control unit 114 can record each data of the audio signal, the captured image, the vehicle state information, and the position information, which are sequentially acquired, in the recording medium 7 in a time series.

The storage unit 12 is composed of a non-volatile memory such as a flash memory or a hard disk drive. The storage unit 12 stores, for example, a program as firmware and various information used by the program. The storage unit 12 also stores various data necessary for the sound source signal acquisition unit 111, the collected sound signal acquisition unit 112, the clock unit 113, and the recording control unit 114 to execute various processes. In the present embodiment, the control unit 11 controls each unit of the vehicle recording apparatus 1 by performing arithmetic processing according to the program stored in the storage unit 12.

A part of the storage area of the storage unit 12 is used as a ring buffer. In this ring buffer, for example, the sound signal acquired by the sound source signal acquisition unit 111, the sound collection signal acquisition unit 112, and each data related to the captured image, the vehicle state information, and the position information, which are acquired by each data acquisition unit, are constantly stored. .. In the ring buffer, when data is stored up to the last area, it returns to the first area and new data is stored. That is, in the ring buffer, new data is sequentially overwritten on the oldest data. Therefore, the storage unit 12 is in a state where the audio signal, the captured image, the vehicle state information, and the position information of each of the past fixed periods are always stored in the storage unit 12. Furthermore, the audio signal, the captured image, the vehicle state information, and the position information stored in the ring buffer of the storage unit 12 are periodically recorded in the recording medium 7 mounted in the recording medium mounting unit 23 according to a command from the control unit 11. It

<1-3. Example of signal recording process by vehicle recorder>
FIG. 3 is a flowchart showing an example of the signal recording process of the vehicle recording device 1. The signal recording process of the vehicle recording device 1 will be described with reference to the process flow of FIG.

The vehicular recording apparatus 1 is activated by, for example, turning on the ignition of the vehicle 3, and starts the process (“start” in FIG. 3).

Next, the vehicular recording apparatus 1 starts to acquire each of the audio signal, the captured image, the vehicle state information, and the position information (step S101). The voice signal is a signal relating to voice generated inside or around the vehicle, and includes a sound source signal supplied to the speaker 5 and a sound collection signal collected by the microphone 6. The vehicle recording device 1 acquires the sound source signal supplied to the speaker 5 via the sound source signal acquisition unit 111, and acquires the sound collection signal collected by the microphone 6 via the sound collection signal acquisition unit 112. The various information acquired by the vehicle recording device 1 is temporarily stored in the ring buffer of the storage unit 12.

Then, the recording control unit 114 temporarily records each data regarding the audio signal, the captured image, the vehicle state information, and the position information, which are temporarily stored in the storage unit 12, on the recording medium 7 (step S102). The audio signal, the captured image, the vehicle state information, and the position information acquired at the common time are associated with each other and recorded in one file formed on the recording medium 7. As the file recorded on the recording medium 7, for example, a file in which the data from the ignition ON to OFF of the vehicle 3 is set as one unit, or a file in which data for each predetermined recording capacity (recording time) is set as one unit is recorded. The method can be appropriately set by the user.

When the vehicle recording device 1 acquires the vehicle state information that the vehicle 3 is impacted via the sensor unit 21, the vehicle recording device 1 associates the audio signals with each other in a predetermined period before and after the impact time, The captured image, the vehicle state information, and the position information are recorded on the recording medium 7 as one file and protected.

Next, it is determined whether or not the ignition of the vehicle 3 has been turned off (step S103). If the vehicle 3 is not in the ignition OFF state (No in step S103), the process returns to step S101, and the acquisition and recording of the audio signal, the captured image, the vehicle state information, and the position information are continued. That is, the acquisition and recording of the audio signal, the captured image, the vehicle state information, and the position information are always performed during the activation of the vehicle recording device 1. When the vehicle 3 is in the ignition OFF state (Yes in step S103), the processing flow shown in FIG. 3 by the vehicle recording device 1 is ended.

According to the above configuration, the sound source signal supplied to the speaker 5 and the sound collection signal collected by the microphone 6 can be recorded in the recording medium 7. Since the raw sound source signal before being output from the speaker 5 is recorded, it is included in the sound collection signal by performing advanced analysis processing after recording the audio signal, as compared with the case where the analysis processing is performed in real time. The audio signal emitted from the speaker 5 can be easily and accurately removed. That is, it becomes possible to easily and accurately remove an unnecessary audio signal from a signal generated inside or around the vehicle and recorded on the recording medium 7.

<1-4. Modified Example of Vehicle Recording Device>
FIG. 4 is a block diagram showing the configuration of the vehicle recording apparatus 1 of the modified example. The control unit 11 of the vehicle recording apparatus 1 of the modified example includes a signal processing unit 115. The function of the signal processing unit 115 included in the control unit 11 is realized by the CPU performing arithmetic processing according to a program. The signal processing unit 115 includes a sound source signal supplied to the speaker 5 acquired via the sound source signal acquisition unit 111, a sound collection signal collected by the microphone 6 acquired via the sound collection signal acquisition unit 112, and the like. Signal processing is performed on the.

In the present embodiment, the signal processing unit 115 uses the sound source signal and the sound collection signal to remove the sound signal emitted from the speaker 5 included in the sound collection signal. Specifically, for example, when a sound source signal as music is supplied to the speaker 5 from an audio device (not shown), the signal related to the music emitted from the speaker 5 is collected by the microphone 6. Included in the sound signal. The signal processing unit 115 removes the audio signal (music) emitted from the speaker 5 included in the sound collection signal, using the sound source signal as music and the sound collection signal including the signal related to the music. ..

FIG. 5 is a diagram for explaining a first example of signal processing in the vehicle recording device 1. For example, the signal processing unit 115 generates an antiphase signal with respect to the sound source signal of the speaker 5 when removing the sound signal emitted from the speaker 5 included in the sound collection signal. The anti-phase signal of the sound source signal of the speaker 5 is generated by a well-known calculation method. Further, the signal processing unit 115 adds the opposite phase signal of the sound source signal to the collected sound signal. As a result, the sound signal emitted from the speaker 5 included in the sound collection signal and the sound source signal whose phase is inverted cancel each other, and a sound collection signal in which the sound signal emitted from the speaker 5 is removed is obtained. be able to.

Further, for example, by using another well-known technique, the signal processing unit 115 uses filter coefficients stored in advance in the storage unit 12 or the like in order to remove the sound signal emitted from the speaker 5 included in the sound collection signal. To use. The signal processing unit 115 sets the filter coefficient and generates an output signal of the filter to which the sound source signal of the speaker 5 is input. Further, the signal processing unit 115 calculates the difference between the collected sound signal and the filter output signal. This makes it possible to obtain a sound collection signal from which the sound signal emitted from the speaker 5 has been removed.

When removing the sound signal emitted from the speaker 5 included in the sound collection signal as described above, the vehicle state information such as the acceleration information and the vehicle speed information regarding the vehicle 3 detected by the sensor unit 21 is reflected. Alternatively, an antiphase signal or a filter coefficient may be generated.

According to the above configuration, in the vehicle recording device 1, the audio signal can be analyzed, and the audio signal emitted from the speaker 5 included in the sound collection signal can be easily removed. .. Therefore, in the vehicular recording apparatus 1, it becomes possible to easily and accurately remove an unnecessary audio signal from a signal relating to the audio generated inside or around the vehicle and recorded in the recording medium 7.

Further, in the present embodiment, the signal processing unit 115 uses the acoustic transfer function to remove the sound signal emitted from the speaker 5 included in the sound collection signal. FIG. 6 is a diagram for explaining a second example of signal processing in the vehicular recording apparatus 1.

The signal processing unit 115 derives an acoustic transfer function between the speaker 5 and the microphone 6 based on a predetermined audio signal (calibration audio signal) supplied to the speaker 5 and collected by the microphone 6. This acoustic transfer function is derived in advance, for example, for each vehicle in which the vehicular recording apparatus 1 is mounted before actually starting the operation of the vehicular recording apparatus 1. The acoustic transfer function is derived by a known calculation method. The acoustic transfer function is derived by reflecting acoustic characteristics, environment characteristics, microphone characteristics, and electric characteristics that are different for each vehicle.

When removing the sound signal emitted from the speaker 5 included in the sound collection signal, the signal processing unit 115 collects the opposite phase signal of the sound source signal after generating the opposite phase signal with respect to the sound source signal of the speaker 5. The acoustic transfer function is applied while being added to the signal.

Further, when using the filter coefficient to remove the sound signal emitted from the speaker 5 included in the sound collection signal, the signal processing unit 115 reflects the acoustic transfer function in the filter coefficient. Then, the signal processing unit 115 calculates the difference between the collected signal and the filter output signal reflecting the acoustic transfer function.

According to the above configuration, when the sound signal emitted from the speaker 5 included in the sound collection signal is removed, various characteristics that may affect the sound signal and differ from vehicle to vehicle can be considered. it can. This makes it possible to improve the accuracy of removing the sound signal emitted from the speaker 5 included in the sound collection signal. That is, it becomes possible to clearly confirm an important voice such as a voice emitted by an occupant or a contact sound of the vehicle.

<2. Second Embodiment>
<2-1. Overview of signal processing equipment>
FIG. 7 is a block diagram showing the configuration of the signal processing device 8 of the second embodiment. The signal processing device 8 may be, for example, a personal computer. The signal processing device 8 is a device that processes a signal related to a sound generated inside or around the vehicle. A display unit 91 and an operation unit 92 are connected to the signal processing device 8.

The display unit 91 may be, for example, a liquid crystal display, an organic EL (Electro Luminescence) display, or the like. The signal processing device 8 can display the operation status related to the signal processing on the screen of the display unit 91.

The operation unit 92 may be, for example, a touch panel, keyboard, mouse, numeric keypad, or the like. The operation unit 92 may be configured by disposing a touch panel on the screen of the display unit 91. The operation unit 92 may be configured by disposing mechanical buttons around the screen of the display unit 91. The operation unit 92 can be operated by the user by inputting commands, information, etc. to the signal processing device 8.

<2-2. Configuration of signal processing device>
The signal processing device 8 includes a control unit 81, a storage unit 82, and a recording medium mounting unit 83.

The control unit 81 is a so-called microcomputer including a CPU, a RAM, and a ROM (not shown). The control unit 81 processes and transmits/receives information based on the program stored in the storage unit 82. The control unit 81 is connected to the storage unit 82, the display unit 91, the operation unit 92, and the recording medium mounting unit 83. The control unit 81 sends and receives various information and data to and from these constituent elements.

The control unit 81 includes a signal processing unit 811. The function of the signal processing unit 811 included in the control unit 81 is realized by the CPU performing arithmetic processing according to a program.

The signal processing unit 811 performs signal processing on a signal relating to a sound generated inside or around the vehicle. The data related to the sound generated inside or around the vehicle is read from the recording medium 7 via the recording medium mounting portion 83. The recording medium 7 includes sound source signal data 71 supplied to a speaker mounted on the vehicle and sound collection signal data 72 collected by a microphone mounted on the vehicle as sound generated inside or around the vehicle. Record.

The signal processing unit 811 uses the sound source signal supplied to the speaker mounted on the vehicle and the sound collection signal collected by the microphone mounted on the vehicle to emit sound from the speaker included in the sound collection signal. Remove the audio signal More specifically, for example, the signal processing unit 811 generates an antiphase signal with respect to the sound source signal of the speaker when removing the sound signal emitted from the speaker included in the sound collection signal. The opposite phase signal of the sound source signal of the speaker is generated by a well-known calculation method. Further, the signal processing unit 811 adds the opposite phase signal of the sound source signal to the sound collection signal. As a result, the sound source signal included in the sound collection signal and the sound source signal whose phase is inverted cancel each other out, and a sound collection signal in which the sound signal emitted from the speaker is removed can be obtained.

Furthermore, the signal processing unit 811 removes the audio signal emitted from the speaker included in the sound collection signal, using the acoustic transfer function. The acoustic transfer function is supplied to the speaker mounted on the vehicle, and is transferred between the speaker and the microphone based on a predetermined audio signal (calibration audio signal) collected by the microphone mounted on the vehicle. It is derived in advance as a function. The acoustic transfer function is derived by a known calculation method. The acoustic transfer function data 73 is recorded in the recording medium 7 together with the sound source signal data 71 and the collected sound signal data 72.

When removing the audio signal emitted from the speaker included in the sound collection signal, the signal processing unit 811 generates an opposite phase signal with respect to the sound source signal of the speaker, and then converts the opposite phase signal of the sound source signal into the sound collection signal. Along with addition, the acoustic transfer function is further applied. When using a filter coefficient to remove the audio signal emitted from the speaker included in the collected signal, the signal processing unit 811 reflects the acoustic transfer function in the filter coefficient. Then, the signal processing unit 811 calculates the difference between the collected sound signal and the filter output signal reflecting the acoustic transfer function.

The storage unit 82 is composed of a non-volatile memory such as a flash memory or a hard disk drive. The storage unit 82 stores, for example, a program as firmware and various information used by the program. In addition, the storage unit 82 stores various data necessary for the signal processing unit 811 to execute various processes. In the present embodiment, the control unit 81 controls each unit of the signal processing device 8 by performing arithmetic processing according to the program stored in the storage unit 82.

The recording medium mounting portion 83 is configured so that the recording medium 7 can be attached and detached. The recording medium 7 is, for example, a memory card, and the recording medium mounting portion 83 in this case is configured as a card slot. The recording medium 7 may be, for example, a magnetic disk, an optical disk, a magneto-optical disk, or the like. In the present embodiment, it is assumed that the recording medium 7 is mounted in the recording medium mounting portion 83, and data can be freely written and read in and from the recording medium 7. Note that the signal processing device 8 may receive the sound source signal data 71, the sound collection signal data 72, and the acoustic transfer function data 73 wirelessly or by wire via a communication unit (not shown).

According to the above configuration, the signal processing device 8 can analyze the audio signal and easily remove the audio signal emitted from the speaker included in the sound collection signal. Therefore, it becomes possible to easily and accurately remove the unnecessary voice signal from the signal relating to the voice generated inside or around the vehicle.

Furthermore, when removing the sound signal emitted from the speaker included in the sound collection signal, various characteristics that may affect the sound signal and that differ from vehicle to vehicle can be considered. This makes it possible to improve the accuracy of removing the sound signal emitted from the speaker included in the sound collection signal. That is, it becomes possible to clearly confirm an important voice such as a voice emitted by an occupant or a contact sound of the vehicle.

<3. Other>
Various technical features disclosed in this specification can be variously modified in addition to the above-described embodiment without departing from the spirit of the technical creation. That is, it should be considered that the above-described embodiments are exemplifications in all respects and are not restrictive. It should be understood that the technical scope of the present invention is shown not by the above description of the embodiments but by the scope of the claims, and includes meanings equivalent to the scope of the claims and all modifications belonging to the scope. Is. Further, the above-described plurality of embodiments and modified examples may be combined and implemented within a possible range.

For example, in the above-described first embodiment, the vehicle recording device 1 that is a drive recorder is installed in the vehicle-mounted device 2 that is a navigation device, but the vehicle recording device 1 and the vehicle-mounted device 2 are separate and independent. The device can be In this case, the vehicle recording device 1 receives a sound source signal supplied to the speaker 5 from, for example, a navigation device, an audio device, or the like.

Further, for example, in the second embodiment, the signal processing device 8 is a personal computer, but the signal processing device 8 may be built in a drive recorder, for example. As a result, the configuration is the same as that of the vehicle recording apparatus 1 of the above modification. Further, the signal processing device 8 may be built in the navigation device, for example.

Further, in the above embodiment, it is described that various functions are realized by software by the arithmetic processing of the CPU according to the program, but some of these functions are realized by an electrical hardware circuit. May be. On the contrary, some of the functions that are realized by the hardware circuit may be realized by software.

1 Vehicle Recording Device 2 Vehicle-mounted Device 3 Vehicle 5 Speaker 6 Microphone 7 Recording Medium 8 Signal Processing Device 23 Recording Medium Mounting Unit 71 Sound Source Signal Data 72 Sound Collection Signal Data 73 Acoustic Transfer Function Data 83 Recording Medium Mounting Unit 111 Sound Source Signal Acquisition Unit 112 sound collection signal acquisition unit 114 recording control unit 115 signal processing unit 811 signal processing unit

Claims (6)

A vehicle recording device for recording a signal relating to a sound generated inside or around a vehicle on a recording medium,
A sound source signal acquisition unit that acquires a sound source signal supplied to a speaker mounted on the vehicle,
A sound collection signal acquisition unit that acquires a sound collection signal collected by a microphone mounted on the vehicle,
A recording control unit for recording the sound source signal and the collected sound signal in the recording medium;
A recording device for a vehicle including the. The vehicle recording apparatus according to claim 1, further comprising: a signal processing unit that removes a sound signal emitted from the speaker included in the sound collection signal by using the sound source signal and the sound collection signal. The signal processing unit derives an acoustic transfer function between the speaker and the microphone based on a predetermined audio signal supplied to the speaker and collected by the microphone, and using the acoustic transfer function, The vehicle recording device according to claim 2, wherein a sound signal emitted from the speaker included in the sound collection signal is removed. A signal processing device for processing a signal relating to a sound generated inside or around a vehicle, comprising:
Using the sound source signal supplied to the speaker mounted on the vehicle and the sound collection signal collected by the microphone mounted on the vehicle, the sound emitted from the speaker included in the sound collection signal A signal processing device comprising a signal processing unit for removing a signal. The signal processing unit uses the acoustic transfer function between the speaker and the microphone, which is derived in advance based on a predetermined audio signal supplied to the speaker and collected by the microphone, to generate the collected signal. The signal processing apparatus according to claim 4, wherein a signal emitted from the included speaker is removed. A signal recording method for recording a signal relating to a sound generated inside or around a vehicle on a recording medium,
Acquiring a sound source signal supplied to a speaker mounted on the vehicle,
Acquiring a sound collection signal collected by a microphone mounted on the vehicle,
Recording the sound source signal and the collected sound signal on the recording medium,
A signal recording method including.

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