Sound generation device for vehicle

Abstract

This sound generation device for a vehicle is mounted on an automobile, and comprises: a sound generation body (100) that has both a sound generation function for generating sound toward the surroundings of the automobile, and a sound collection function for outputting an output signal indicating sound collected from the surroundings of the automobile; a recording unit (172) in which sound source data corresponding to a predetermined sound is recorded; a collected sound determination unit (S310, S330) that determines whether or not the sound collected by the sound generation body is the predetermined sound, on the basis of the output signal outputted from the sound generation body; and a sound generation control unit (S320, S360, S360A) that, if the collected sound determination unit determines that the sound collected by the sound generation body is the predetermined sound, controls the sound generation body so that sound is generated from the sound generation body, on the basis of the sound source data recorded in the recording unit.

Description

Vehicle sound generation device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2024-27616, filed on February 27, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a sound generation device for a vehicle.

[0003] Conventionally, a sound generating device has been proposed that is mounted on an automobile and generates a warning sound from a speaker to the surroundings of the automobile (see, for example, Patent Document 1). The speaker also functions as a microphone that outputs an electromotive force signal based on sounds collected from the surroundings of the automobile. A control circuit estimates the noise level around the automobile based on the electromotive force signal, and adjusts the volume of the warning sound output from the speaker based on the estimated noise level.

[0004] Japanese Patent Application Laid-Open No. 2021-103869

[0005] As described above, the sound generating device of Patent Document 1 adjusts the volume of the alarm sound output from the speaker based on the electromotive force signal output from the speaker. However, according to the inventor's investigation, there is no mention of spontaneous sound generation from the speaker based on the sound collected by the speaker. The present disclosure aims to provide a sound generating device for a vehicle that spontaneously generates sound from the speaker based on the sound collected by the speaker.

[0006] According to one aspect of the present disclosure, a sound generation device for a vehicle includes: a sound generation body that is mounted on an automobile and has both a sound generation function of generating sound toward the surroundings of the automobile and a sound collection function of outputting an output signal indicating sound collected from the surroundings of the automobile; a recording unit in which sound source data corresponding to a predetermined sound is recorded; a sound collection determination unit that determines whether the sound collected by the sound generation body is the predetermined sound based on the output signal output from the sound generation body; and a sound generation control unit that, when the sound collection determination unit determines that the sound collected by the sound generation body is the predetermined sound, controls the sound generation body to generate sound based on the sound source data recorded in the recording unit.

[0007] Therefore, it is possible to provide a sound generating device for a vehicle that spontaneously generates a sound from a speaker based on sounds collected by the speaker.

[0008] 1 is an electrical circuit diagram showing a partial configuration of the electrical configuration of the in-vehicle alert system in the first embodiment of the present disclosure. FIG. 2 is an electrical circuit diagram showing the remaining configuration of the electrical configuration of the in-vehicle alert system in the first embodiment of the present disclosure. FIG. 3 is a block diagram showing the internal configuration of a microcomputer of the in-vehicle sound generation device of the in-vehicle alert system in the first embodiment of FIG. 1. FIG. 4 is a flowchart showing the overall operation of the in-vehicle sound generation device of the in-vehicle alert system in the first embodiment of FIG. 1. FIG. 5 is a flowchart showing details of a sound collection control process by the microcomputer of the in-vehicle sound generation device of the in-vehicle alert system in the first embodiment of FIG. 1. FIG. 6 is a flowchart showing details of a sound collection type determination process by the microcomputer of the in-vehicle sound generation device of the in-vehicle alert system in the first embodiment of FIG. 1. FIG. 7 is a flowchart showing details of a threshold setting process by the microcomputer of the in-vehicle sound generation device of the in-vehicle alert system in the first embodiment of FIG. 1. FIG. 8 is a flowchart showing details of a sound pressure control process by the microcomputer of the in-vehicle sound generation device of the in-vehicle alert system in the first embodiment of FIG. 1. FIG. 9 is a flowchart showing details of a sound collection type determination process by the microcomputer of the in-vehicle sound generation device of the in-vehicle alert system in the second embodiment of the present disclosure.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, identical or equivalent parts are denoted by the same reference numerals in the drawings to simplify the description.

[0010] 1 and 2 are schematic diagrams showing the overall configuration of an electric circuit of an in-vehicle system 1 according to a first embodiment of the present invention. As shown in FIGS. 1 and 2, the in-vehicle system 1 according to the present embodiment includes a vehicle sound generation device 10, a monitoring device 20, and an external vehicle communication device 30.

[0011] The sound generation device 10 for a vehicle includes a speaker 100 , a power amplifier 110 , a preamplifier 120 , a comparator 130 , a power supply circuit 140 , a vehicle communication unit 150 , a timer circuit 160 , and a microcomputer 170 .

[0012] The speaker 100 is a sound generator that emits sound toward the surroundings of the vehicle based on an output signal from the power amplifier 110. The speaker 100 collects sounds from the surroundings of the vehicle and outputs an electromotive force signal based on the collected sounds.

[0013] That is, the speaker 100 has both a sound generating function for emitting sound toward the surroundings of the vehicle and a sound collecting function for outputting an electromotive force signal indicative of the sound collected from the surroundings of the vehicle as a microphone. The electromotive force signal is a signal indicative of the sound information collected by the speaker 100 from the surroundings of the vehicle.

[0014] Specifically, speaker 100 includes a vibrating body and a magnetic circuit. The magnetic circuit vibrates the vibrating body to generate sound based on an output signal from power amplifier 110. When the vibrating body vibrates due to sounds collected from around the vehicle, the magnetic circuit outputs an electromotive force signal in response to the vibration of the vibrating body.

[0015] The power amplifier 110 is a power amplifier that operates using power supplied from the vehicle battery Ba. Specifically, the power amplifier 110 amplifies the power of the sound signal output from the microcomputer 170 and outputs the power-amplified sound signal as an output signal.

[0016] Here, the sound generation signal is an audio signal generated by the microcomputer 170 based on sound source data, and serves to adjust the sound pressure of the speaker 100 when it generates sound to a target sound pressure, as will be described later.

[0017] The preamplifier 120 operates based on power supplied from the vehicle battery Ba. Specifically, the preamplifier 120 amplifies the electromotive force signal output from the speaker 100 and outputs the amplified electromotive force signal as a collected sound signal to the microcomputer 170 and the comparator 130.

[0018] The comparator 130 operates based on power supplied from the vehicle battery Ba. The collected sound signal output from the preamplifier 120 is input to a non-inverting input terminal of the comparator 130. The threshold signal from the microcomputer 170 is input to an inverting input terminal of the comparator 130.

[0019] The comparator 130 compares the level of the collected sound signal output from the preamplifier 120 with the level of the threshold signal output from the microcomputer 170, and outputs the comparison result to the microcomputer 170. Here, the level of the collected sound signal means the signal strength of the collected sound signal, and the level of the threshold signal means the signal strength of the threshold signal.

[0020] In this embodiment, the threshold signal is a signal indicating a threshold for comparing the level of the collected sound signal. The threshold is set by a threshold setting process by the microcomputer 170, as will be described later.

[0021] The power supply circuit 140 connects or disconnects the positive terminal of the in-vehicle battery Ba and the positive power supply terminal of the power amplifier 110. The power supply circuit 140 connects or disconnects the positive terminal of the in-vehicle battery Ba and the positive power supply terminal of the preamplifier 120.

[0022] The power supply circuit 140 connects or disconnects the positive terminal of the in-vehicle battery Ba and the positive power supply terminal of the comparator 130. The vehicle communication unit 150 communicates with the vehicle communication unit of the exterior communication device 30. The vehicle communication unit 150 communicates with the vehicle communication unit of the monitoring device 20. The vehicle communication unit 150 also receives sound generation requests from other electronic control devices.

[0023] The microcomputer 170 operates using output power from the vehicle battery Ba. As shown in Fig. 3, the microcomputer 170 includes a central processing unit 171, a memory 172, a digital-to-analog converter 175, and an analog-to-digital converter 177. The central processing unit 171 executes sound collection control processing in accordance with a computer program pre-recorded in the memory 172 (i.e., the recording unit). The memory 172 is a non-transitory tangible storage medium.

[0024] In conjunction with the execution of the sound collection control process, the central processing unit 171 performs operations such as sound generation by the speaker 100, monitoring of the surroundings of the vehicle by the monitoring sensor 210, and reporting by the external vehicle communication device 30 based on the sound collected by the speaker 100 and communication with the electronic control unit 40.

[0025] The timer circuit 160 periodically issues a sound collection request to the microcomputer 170. The electronic control unit 40 is an electronic control unit that executes, for example, control of the illumination of the hazard lights of the vehicle, control of the vehicle door lock, etc. The electronic control unit 40 detects various vehicle information such as the illumination status of the hazard lights and the status of the vehicle door lock.

[0026] As shown in FIG. 3, the memory 172 stores a feature data group 172a, a sound source data group 172b, a sound source data maximum sound pressure value 172c, a prominent sound pressure 172d, and the like in addition to a computer program.

[0027] The feature data group 172a includes a feature data group of sounds of the pronunciation condition and a feature data group of sounds of the surroundings monitoring condition. The sounds of the pronunciation condition and the sounds of the surroundings monitoring condition are each predetermined sounds. The sounds of the pronunciation condition include question voices, command voices, and animal activity sounds such as cat meows and birdsong. The sounds of the surroundings monitoring condition are abnormality occurrence sounds that occur when something abnormal happens to the car (for example, the sound of the car crashing).

[0028] The question voice is a voice used by the occupant to ask about the current state of the vehicle. The command voice is a voice used by the occupant to instruct the vehicle to turn on or off the hazard lights, and a voice used by the occupant to instruct the vehicle to lock or unlock the vehicle doors.

[0029] Automobile destruction sounds include the sounds made when thieves who steal automobiles or on-board parts strike an automobile with tools or the like to destroy it, and the sounds made when thieves forcibly peel plastic parts or the like off an automobile.

[0030] The sound source data group 172b is digital data representing sound source signals that represent notification sounds, answering sounds, auxiliary sounds, bird and animal repellent sounds such as cat and bird repellent sounds, warning sounds, etc. Notification sounds include acceptance sounds, rejection sounds, etc.

[0031] The acceptance sound is an answerback sound that notifies the vehicle operator that a command has been accepted when the vehicle operator issues a command by voice. The rejection sound is an answerback sound that notifies the vehicle operator that a command has been rejected when the vehicle operator issues a command by voice.

[0032] The answering voice is a voice that answers a question from a passenger or the like. The answering voice is a voice that explains, for example, vehicle information detected by the electronic control unit 40. The auxiliary voice is a voice that explains the reason why the vehicle has rejected a command from a passenger or the like.

[0033] The bird and animal repellent sound may be, for example, a sound that repels cats (such as an explosion) and is used to keep cats away from cars, or may be, for example, a sound that repels birds (such as a gunshot) and is used to keep birds away from cars.

[0034] The warning sound is a warning sound to warn a thief attempting to steal a vehicle. The warning sound may be, for example, a sound to notify a thief that the vehicle is under surveillance, or an alarm sound such as a siren.

[0035] The sound source data maximum sound pressure value 172c is the maximum value of the sound pressure output from the speaker 100 when sound is generated from the speaker 100 based on the sound generation signal. The protruding sound pressure 172d is a sound pressure value used to calculate the sound pressure output from the speaker 100, and is a predetermined value.

[0036] Furthermore, a large noise counter 172e and a small noise counter 172f are set in the memory 172. The large noise counter 172e and the small noise counter 172f are used to set a threshold value based on the collected sound pressure judgment value, as will be described later.

[0037] Furthermore, the analog-to-digital converter 177 converts into a digital signal the collected sound signal, which is an analog signal output from the preamplifier 120. The digital-to-analog converter 175 converts the sound data, which is a digital signal, into a sound signal, which is an analog signal, as will be described later.

[0038] 2, the monitoring device 20 includes a control circuit 200, a monitoring sensor 210, a power supply circuit 220, and a vehicle communication unit 230. The control circuit 200 is configured by a microcomputer and a memory.

[0039] The control circuit 200 executes control processing to cause the monitoring sensor 210 to monitor the surroundings of the vehicle based on a monitoring request from the vehicle sound generation device 10, and to request the vehicle sound generation device 10 to generate or collect sound based on the monitoring results of the monitoring sensor 210.

[0040] The monitoring sensor 210 is controlled by the control circuit 200 to monitor the surroundings of the vehicle. In this embodiment, the monitoring sensor 210 is a radar for monitoring the surroundings of the vehicle using electromagnetic waves such as millimeter waves, laser light, or ultrasonic waves, and a camera for capturing images of the surroundings of the vehicle.

[0041] The power supply circuit 220 is controlled by the control circuit 200 to connect or disconnect the positive terminal of the in-vehicle battery Ba and the positive power supply terminal of the monitoring sensor 210. The vehicle communication unit 230 communicates with the vehicle communication unit 150 of the vehicle sound generation device 10.

[0042] 3, the exterior communication device 30 is a communication device including a control circuit 300, a memory 300a, a radio circuit 310, a power supply circuit 320, and a vehicle communication unit 330. The control circuit 300 is configured by a microcomputer and a memory.

[0043] The control circuit 300 executes a communication process to report to a monitoring center, such as a security company, outside the vehicle via the wireless circuit 310 based on a monitoring request from the vehicle sound generation device 10. The wireless circuit 310 is controlled by the control circuit 200 and communicates wirelessly with the monitoring center outside the vehicle.

[0044] The memory 300a stores the sound generator mounting position attenuation amount, which is a correction value for sound pressure used to calculate the target sound pressure, and indicates the amount of sound pressure attenuation determined by the mounting position of the speaker 100 in the automobile.

[0045] The power supply circuit 320 is controlled by the control circuit 300 to connect or disconnect the positive terminal of the in-vehicle battery Ba and the positive power supply terminal of the radio circuit 310. The vehicle communication unit 330 communicates with the vehicle communication unit 150 of the vehicle sound generation device 10.

[0046] 1, sound generation control 173, power supply control 174, wake-up 176, threshold setting 178, sound collection request 179, sound collection type determination 180, and sound collection sound pressure determination 181 indicate operations performed by the microcomputer 170. Similarly, sound collection control 182, monitoring request 183, sound collection request 184, and sound generation request 185 indicate an outline of operations performed by the microcomputer 170.

[0047] 2, power supply control 240, sound generation request 241, sound collection request 242, and monitoring request 243 indicate the operation of the monitoring device 20. In Fig. 3, power supply control 340, sound generation request 341, sound collection request 342, and monitoring request 343 indicate an outline of the operation of the exterior communication device 30.

[0048] The operation of the in-vehicle system 1 of this embodiment will be described with reference to FIGS.

[0049] First, in the monitoring device 20, when the control circuit 200 receives a monitoring request from the vehicle communication unit 150 of the vehicle sound generation device 10 via the vehicle communication unit 230, it controls the monitoring device 20 to cause the monitoring device 20 to monitor the surroundings of the vehicle.

[0050] At this time, when the control circuit 200 detects, based on the results of monitoring by the monitoring device 20, for example, that an object has been present around the vehicle for a certain period of time or more, it determines that a suspicious person is present around the vehicle.

[0051] In response to this, the control circuit 200 transmits a sound generation request and a sound collection request to the vehicle communication unit 150 of the vehicle sound generation device 10 via the vehicle communication unit 230 .

[0052] Meanwhile, in the exterior communication device 30, the control circuit 300 receives a monitoring request from the vehicle communication unit 150 of the vehicle sound generation device 10 via the vehicle communication unit 330. In response, the control circuit 300 wirelessly communicates with the monitoring center via the wireless circuit 310 to inform them that an abnormality has occurred around the vehicle.

[0053] Meanwhile, in the vehicle sound generation device 10, when the microcomputer 170 receives a sound generation request from the monitoring device 20, it outputs a sound generation signal indicating a warning sound or the like to the power amplifier 110. Therefore, the power amplifier 110 power-amplifies the sound generation signal and outputs it to the speaker 100.

[0054] Accordingly, the speaker 100 outputs a warning sound or the like to warn suspicious people around the vehicle based on the output signal output from the power amplifier 110 .

[0055] In the sound generation device 10 for a vehicle, when the microcomputer 170 receives a sound collection request from the monitoring device 20 , it waits for a sound collection signal to be output from the preamplifier 120 .

[0056] Here, the preamplifier 120 amplifies the power of the electromotive force signal output from the speaker 100 and outputs the power-amplified signal to the microcomputer 170 as a collected sound signal.

[0057] Accordingly, the microcomputer 170 converts the collected sound signal output from the preamplifier 120 into a digital signal. Based on this digital signal, the microcomputer 170 controls the speaker 100 to output a warning sound or the like from the speaker 100, as will be described later.

[0058] In the vehicle sound generation device 10, when the microcomputer 170 receives a sound generation request from the exterior communication device 30, it outputs a sound generation signal indicating a warning sound or the like to the power amplifier 110. Therefore, the power amplifier 110 power-amplifies the sound generation signal and outputs it to the speaker 100.

[0059] Accordingly, the speaker 100 outputs a warning sound or the like to warn suspicious people around the vehicle based on the output signal output from the power amplifier 110 .

[0060] In the sound generation device 10 for a vehicle, when the microcomputer 170 receives a sound collection request from the exterior communication device 30 , it waits for a sound collection signal to be output from the preamplifier 120 .

[0061] At this time, the preamplifier 120 amplifies the power of the electromotive force signal output from the speaker 100 and outputs the power-amplified signal to the microcomputer 170 as a collected sound signal.

[0062] Accordingly, the microcomputer 170 converts the collected sound signal output from the preamplifier 120 into a digital signal. Based on this digital signal, the microcomputer 170 controls the speaker 100 to output a warning sound or the like from the speaker 100, as will be described later.

[0063] Next, a specific example of the sound generation operation of the sound generation device 10 for a vehicle of the in-vehicle system 1 of this embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart showing the sound generation operation of the sound generation device 10 for a vehicle.

[0064] First, when the microcomputer 170 is in a sleep state, the power supply circuit 140, as a stop control unit, opens the connection between the positive terminal of the vehicle battery Ba and the positive power supply terminal of the power amplifier 110 based on the output signal of the microcomputer 170.

[0065] Therefore, when the microcomputer 170 is in the sleep state, the power supply circuit 140 stops supplying power from the vehicle battery Ba to the power amplifier 110. As a result, the power amplifier 110 stops operating, and its output becomes a high impedance state.

[0066] Meanwhile, the power supply circuit 140 connects the positive terminal of the vehicle battery Ba to the positive power supply terminal of the preamplifier 120. Therefore, the power supply circuit 140 supplies power from the vehicle battery Ba to the preamplifier 120. This keeps the preamplifier 120 operating when the microcomputer 170 is in a sleep state.

[0067] For this reason, speaker 100 collects sounds from around the vehicle and outputs an electromotive force signal based on the collected sounds to preamplifier 120. Preamplifier 120 outputs a collected sound signal, which is the electromotive force signal output from speaker 100, amplified based on the power supplied from on-board battery Ba, to microcomputer 170 and comparator 130.

[0068] Furthermore, the power supply circuit 140 connects the positive terminal of the vehicle battery Ba to the positive power supply terminal of the comparator 130. Therefore, the power supply circuit 140 supplies power from the vehicle battery Ba to the comparator 130.

[0069] At this time, the microcomputer 170 is in a sleep state while outputting the threshold signal to the comparator 130. Therefore, the comparator 130 compares the level of the threshold signal output from the microcomputer 170 with the level of the collected sound signal output from the preamplifier 120 based on the power supplied from the vehicle battery Ba.

[0070] Here, when the level of the collected signal from the speaker 100 is greater than the level of the threshold signal (i.e., the threshold), the level of the output signal given from the comparator 130 to the microcomputer 170 becomes high.

[0071] That is, the comparator 130 functions as a startup control unit and controls the microcomputer 170 to wake up the microcomputer 170. In this case, the answer to step S100 is YES.

[0072] Accordingly, in step S110, the microcomputer 170 transitions from the sleep state to the wake-up state based on the output signal of the comparator 130. That is, the comparator 130 controls the microcomputer 170 to transition the microcomputer 170 from the sleep state to the wake-up state.

[0073] On the other hand, when the level of the collected signal from the speaker 100 is equal to or lower than the level of the threshold signal (i.e., the threshold), the level of the output signal given from the comparator 130 to the microcomputer 170 becomes low. In this case, the result in step S100 is NO, and the microcomputer 170 maintains the sleep state based on the output signal from the comparator 130.

[0074] At this time, if a sound collection request is given to the microcomputer 170 from any one of the monitoring device 20, the exterior communication device 30, or the internal timer circuit, the answer is YES in step S120. The microcomputer 170 transitions from the sleep state to the wake-up state in step S110.

[0075] In this way, the microcomputer 170 transitions from the sleep state to the wake-up state in response to the output signal of the comparator 130 or a sound collection request from the monitoring device 20, the exterior communication device 30, or the timer circuit 160. Thereafter, the microcomputer 170 starts executing the sound collection control process in step S130.

[0076] In addition, if the level of the sound collection signal from the speaker 100 is below the level of the threshold signal and no sound collection request is given to the microcomputer 170 from any of the monitoring device 20, the exterior communication device 30, or the timer circuit 160, the following occurs.

[0077] That is, the level of the output signal given from the comparator 130 to the microcomputer 170 becomes low, the result in step S120 becomes NO, and the sleep state of the microcomputer 170 is maintained.

[0078] Next, details of the sound collection control process by the microcomputer 170 of this embodiment will be described with reference to Fig. 5. Fig. 5 is a flowchart showing details of the sound collection control process by the microcomputer 170.

[0079] The microcomputer 170 executes the sound collection control process in accordance with the flowchart of Fig. 5. The execution of the sound collection control process is started by the microcomputer 170.

[0080] First, in step S200, the microcomputer 170 activates the analog-to-digital converter 177. Furthermore, in step S200, the microcomputer 170 converts the collected sound signal output from the preamplifier 120 into a digital signal by the analog-to-digital converter 177.

[0081] Next, in step S210, the microcomputer 170, functioning as a noise calculation unit and a sound pressure calculation unit, calculates a collected sound pressure judgment value based on the converted digital signal. Furthermore, the microcomputer 170 records the calculated collected sound pressure judgment value in the memory 172.

[0082] In this embodiment, the collected sound pressure judgment value is a value obtained by converting the level of the collected sound signal into a sound pressure value, and is a sound pressure value that indicates the sound pressure of noise around the automobile.

[0083] For example, the microcomputer 170 may calculate the effective value of the sound collection signal for a certain period as the sound collection sound pressure judgment value. Alternatively, the microcomputer 170 may obtain the effective values ​​of the sound collection signal for multiple periods and calculate the average value of the effective values ​​for the multiple periods as the sound collection sound pressure judgment value.

[0084] Next, in step S220, the microcomputer 170 executes a sound collection type determination process based on the digital signal of the sound collection signal obtained by the analog-to-digital converter 177. As will be described later, the sound collection type determination process executes processes such as sounding from the speaker 100, monitoring the surroundings of the vehicle, and reporting to a monitoring center based on the digital signal.

[0085] Such sound collection control processing is repeatedly executed every time the microcomputer 170 wakes up. Therefore, the calculation of the sound collection sound pressure determination value in step S210 and the sound collection type determination processing in step S220 are repeatedly executed every time the microcomputer 170 wakes up.

[0086] Next, details of the sound collection type discrimination process by the microcomputer 170 of this embodiment will be described with reference to Fig. 6. The microcomputer 170 executes the sound collection type discrimination process according to the flowchart of Fig. 6.

[0087] First, in step S300, the microcomputer 170 reads the digital signal of the collected sound signal obtained by the analog-to-digital converter 177. In addition, in step S300, the microcomputer 170 reads the feature data group 172a from the memory 172.

[0088] Next, the microcomputer 170 executes the control processes of steps S310 and S320 and steps S330, S340, S350, and S360 in parallel. In step S310, the microcomputer 170 determines whether the sound collected by the speaker 100 satisfies the sound generation conditions based on the feature data group 172a and the digital signal. Note that in steps S310 and S330 in FIG. 6, "collected sound" is an abbreviation for the sound collected by the speaker 100.

[0089] Specifically, in step S310, the microcomputer 170, as a sound collection determination unit, determines whether the characteristics of the sound collected by the speaker 100 match any of the feature data in the sound feature data group of the sound generation conditions. Here, "match" does not necessarily mean that the sound features and the feature data match perfectly, but also includes cases where it is estimated that the sound features and the feature data match.

[0090] The sound features and sound feature data each refer to the frequency characteristics of the sound. Therefore, in step S310, the microcomputer 170 determines whether the sound collected by the speaker 100 and any of the feature data in the sound feature data group of the sound production conditions have common frequency characteristics. This determines whether the sound features collected by the speaker 100 match any of the feature data in the sound feature data group of the sound production conditions.

[0091] When the microcomputer 170 determines whether the sound features match the feature data, it can use known techniques that utilize analysis methods such as pattern comparison using formants, spectra, or cepstrum, which is the inverse transform thereof, as units.

[0092] In this way, the microcomputer 170 classifies the sounds collected by the speaker 100. In other words, the microcomputer 170 determines whether the sound collected by the speaker 100 matches any of the sounds of the sound generation conditions, such as a question voice, a command voice, or the active sounds of birds and animals, such as a cat crying or a bird singing.

[0093] Note that, with the main purpose of preventing overdetermination in step S310, the microcomputer 170 may also include the result of determining whether the collected sound pressure determination value is within the range of sound pressure expected for the stratified sound. For example, the microcomputer 170 stratifies the sound collected by the speaker 100, and if the collected sound pressure determination value is outside the range of sound pressure expected for this stratified sound, it determines that the sound collected by the speaker 100 does not match the feature data.

[0094] Thereafter, in step S310, the microcomputer 170 makes a YES determination if the characteristics of the sound collected by the speaker 100 match any of the characteristic data in the sound characteristic data group 172a of the sound generation conditions.

[0095] Accordingly, in step S320, the microcomputer 170, as the first sound generation control unit, selects sound source data corresponding to the sound collected by the speaker 100 from the sound source data group 172b.

[0096] Accordingly, the microcomputer 170, as will be described later, obtains pronunciation data based on the selected sound source data, converts the obtained pronunciation data into an analog pronunciation signal by the digital-to-analog converter 175, and outputs it to the power amplifier 110.

[0097] The power amplifier 110 amplifies the power of the sound signal and outputs it to the speaker 100. The speaker 100 produces sound based on the output signal of the power amplifier 110. As a result, the speaker 100 produces sound based on the sound source data in the sound source data group 172b that corresponds to the sound collected by the speaker 100. Thereafter, the microcomputer 170 ends the execution of the sound collection type determination process.

[0098] Furthermore, in step S310, the microcomputer 170 determines that the result is NO if the characteristics of the sound collected by the speaker 100 do not match any of the characteristic data in the sound characteristic data group of the sound production conditions. In other words, the microcomputer 170 determines that the result is NO if the sound collected by the speaker 100 does not match any of the sounds in the sound production conditions. Accordingly, the microcomputer 170 executes the threshold setting process in step S370.

[0099] Meanwhile, in step S330, the microcomputer 170 determines whether or not the sound collected by the speaker 100 is a sound that satisfies the surroundings monitoring conditions, based on the characteristic data of the sound that satisfies the surroundings monitoring conditions and the digital signal.

[0100] That is, in step S330, the microcomputer 170, as a sound collection determination unit, determines whether the characteristics of the sound collected by the speaker 100 match the sound characteristic data of the surrounding monitoring conditions. Here, similar to step S310, "match" does not necessarily mean that the sound characteristics and the characteristic data match perfectly, but also includes cases where it is estimated that the sound characteristics and the characteristic data match.

[0101] That is, the microcomputer 170 determines whether the sound collected by the speaker 100 and the sound characteristic data of the surroundings monitoring conditions have common frequency characteristics, thereby determining whether the characteristics of the sound collected by the speaker 100 match the sound characteristic data of the surroundings monitoring conditions.

[0102] At this time, in step S330, the microcomputer 170 determines YES when the characteristics of the sound collected by the speaker 100 match the characteristic data of the surroundings monitoring conditions.

[0103] Accordingly, in step S340, the microcomputer 170, as a monitoring requesting unit, transmits a monitoring request to the monitoring device 20 through the vehicle communication unit 150. This requests the monitoring device 20 to monitor the surroundings of the vehicle.

[0104] Furthermore, in step S340, the microcomputer 170, as an external reporting unit, transmits a monitoring request to the exterior communication device 30 through the vehicle communication unit 150. This requests the exterior communication device 30 to report that an abnormality such as theft has occurred in the vehicle to a monitoring center or the like of a security company or the like outside the vehicle.

[0105] Here, in the monitoring device 20, when the control circuit 200 receives a monitoring request through the vehicle communication unit 230, it controls the power supply circuit 220 to connect the positive terminal of the vehicle battery Ba and the positive power supply terminal of the monitoring sensor 210.

[0106] This starts the supply of power from the vehicle battery Ba to the monitoring sensor 210. Accordingly, the control circuit 200 controls the monitoring sensor 210 to monitor the surroundings of the vehicle using a radar or a camera, and the monitoring data acquired by the radar or the camera is recorded in memory.

[0107] On the other hand, in the exterior communication device 30, when the control circuit 300 receives a monitoring request through the vehicle communication unit 330, it controls the power supply circuit 320 to connect the positive terminal of the vehicle battery Ba and the positive power supply terminal of the radio circuit 310.

[0108] This starts the supply of power from the vehicle battery Ba to the radio circuit 310. In response to this, the control circuit 300 controls the radio circuit 310 to issue a monitoring request to a monitoring center, etc. This requests the monitoring center, etc. to monitor the vehicle because an abnormality such as theft or vandalism has occurred in the vehicle.

[0109] Next, in step S350, the microcomputer 170, as the pronunciation request determination unit, determines whether or not a pronunciation request has been received from at least one of the monitoring device 20 and the exterior communication device 30 via the vehicle communication unit 150. In other words, the microcomputer 170 determines whether or not a pronunciation request has been received from at least one of the monitoring device 20 and the exterior communication device 30.

[0110] At this time, the microcomputer 170 determines YES in step S350 when it receives a sound generation request from at least one of the monitoring device 20 and the exterior communication device 30 via the vehicle communication unit 150. In other words, the microcomputer 170 determines that a sound generation request has been made by at least one of the monitoring device 20 and the exterior communication device 30.

[0111] Accordingly, in step S360, the microcomputer 170, as the second sound generation control unit, selects sound source data representing a warning sound from the sound source data group 172b. As will be described later, the microcomputer 170 obtains sound generation data based on the selected sound source data, converts the obtained sound generation data into a sound generation signal by the digital-to-analog converter 175, and outputs the sound generation signal to the power amplifier 110.

[0112] The power amplifier 110 amplifies the power of the sound signal and outputs it to the speaker 100. The speaker 100 produces a warning sound based on the output signal of the power amplifier 110. That is, the speaker 100 produces a warning sound based on the sound source data in the sound source data group 172b that corresponds to the sound collected by the speaker 100. Thereafter, the microcomputer 170 ends the execution of the sound collection type determination process.

[0113] Furthermore, in step S330, if the characteristics of the sound collected by the speaker 100 do not match the sound characteristic data of the surroundings monitoring conditions, the microcomputer 170 determines NO.

[0114] In other words, the microcomputer 170 determines that the characteristics of the sound collected by the speaker 100 do not match the characteristic data of either the sound emission condition or the sound monitoring condition. Accordingly, the microcomputer 170 executes a threshold setting process in step S370.

[0115] Next, a specific example in which the microcomputer 170 in this embodiment causes the speaker 100 to spontaneously produce sound based on the sound collected by the speaker 100 will be described.

[0116] For example, in step S310, the microcomputer 170 determines YES when the characteristics of the sound collected by the speaker 100 match the characteristic data of a cat's cry, which is the sound generation condition.

[0117] Accordingly, in step S320, the microcomputer 170, as the sound generation control unit, causes the speaker 100 to generate a cat-repelling sound based on the sound source data of the cat-repelling sound corresponding to the cat's cry, which is included in the sound source data group 172b. This makes it possible to keep cats that have entered the engine compartment or the like of the automobile away from the automobile.

[0118] In step S310, the microcomputer 170 makes a YES determination when the characteristics of the sound collected by the speaker 100 match the characteristic data of the bird song that is the sound generation condition.

[0119] Accordingly, in step S320, the microcomputer 170 causes the speaker 100 to emit a bird-repelling sound based on the bird-repelling sound sound source data corresponding to the bird calls in the sound source data group 172b, thereby making it possible to repel birds that have entered the engine compartment or the like of the automobile.

[0120] In step S310, the microcomputer 170 determines YES if the characteristics of the sound collected by the speaker 100 match the characteristic data of the question voice, which is the pronunciation condition.

[0121] Accordingly, in step S320, the microcomputer 170 causes the speaker 100 to emit an answer voice based on the sound source data of the answer voice corresponding to the question voice from the sound source data group 172b.

[0122] For example, when a question voice such as "Please tell me the current state of the car" is collected by the speaker 100, the microcomputer 170 determines the state of the car based on the vehicle signal input from the electronic control unit 40. For example, when the microcomputer 170 determines that a door is ajar, it causes the speaker 100 to output a response voice such as "The car door is ajar."

[0123] In step S310, the microcomputer 170 makes a YES determination when the characteristics of the sound collected by the speaker 100 match the characteristic data of the command voice, which is the sound generation condition.

[0124] Accordingly, in step S320, the microcomputer 170 causes the speaker 100 to emit a sound based on the sound source data of the acceptance sound or rejection sound corresponding to the command sound from the sound source data group 172b.

[0125] When the speaker 100 picks up a command voice such as "Turn on the hazard lights," the microcomputer 170 outputs an acceptance sound indicating that the command from the occupant has been accepted from the speaker 100. In response to this, the microcomputer 170 controls the electronic control device 40 to turn on the hazard lights.

[0126] When the speaker 100 picks up a command voice such as "Please turn off the hazard lights," the microcomputer 170 outputs an acceptance sound indicating that the command from the occupant has been accepted from the speaker 100. In response to this, the microcomputer 170 controls the electronic control device 40 to turn off the hazard lights.

[0127] For example, when a command voice such as "Please lock the car doors" is collected by the speaker 100, the microcomputer 170 causes the speaker 100 to output an acceptance sound indicating that the command voice from the occupant has been accepted.

[0128] In addition, when the microcomputer 170 determines that the vehicle door is ajar based on the vehicle signal input from the electronic control unit 40, it outputs a rejection sound from the speaker 100 indicating that the command voice from the occupant is being rejected.

[0129] In addition, the microcomputer 170 can also cause the speaker 100 to output an auxiliary voice such as "The door is ajar."

[0130] Furthermore, in step S330, the microcomputer 170 determines YES when the characteristics of the sound collected by the speaker 100 match the characteristic data of the automobile crashing sound, which is the surroundings monitoring condition.

[0131] Accordingly, in step S340, the microcomputer 170 transmits a monitoring request to each of the exterior communication device 30 and the monitoring device 20 via the vehicle communication unit 150.

[0132] Thus, when the control circuit 200 of the monitoring device 20 receives a monitoring request via the vehicle communication unit 230, it determines whether or not there is a suspicious person around the vehicle based on the detection signal of the monitoring sensor 210.

[0133] For example, if an object is present around the vehicle for a certain period of time or longer, the control circuit 200 determines that a suspicious person is present around the vehicle. This confirms or suspects the presence of a thief attempting to steal the vehicle or vehicle parts around the vehicle. Accordingly, the control circuit 200 outputs a request to the microcomputer 170 to sound an alarm via the vehicle communication units 230 and 150.

[0134] On the other hand, when the control circuit 300 of the exterior communication device 30 receives a monitoring request via the vehicle communication unit 330, it controls the wireless circuit 310 to transmit the monitoring request to the monitoring center, thereby making the automobile a target for monitoring by the monitoring center.

[0135] The monitoring center then detects the presence of a suspicious person around the vehicle and transmits a suspicious person report to the exterior communication device 30, reporting the presence of a suspicious person around the vehicle.

[0136] The control circuit 300 then receives the suspicious person report from the monitoring center via the wireless circuit 310. This confirms or suspects the presence of a thief stealing the vehicle or vehicle parts around the vehicle. The control circuit 300 then outputs a request to the microcomputer 170 to sound an alarm via the vehicle communication units 330 and 150.

[0137] Next, when the microcomputer 170 receives a sound generation request from at least one of the control circuits 200 and 300, it determines in step S350 that a sound generation request has been made and makes a YES determination.

[0138] In response to this, in step S360, the microcomputer 170 outputs an alarm sound from the speaker 100. This serves as an audio warning to thieves who may steal the automobile or automobile parts. The alarm sound may be something like "Your automobile is being monitored."

[0139] Next, details of the threshold setting process by the microcomputer 170 of this embodiment will be described with reference to Fig. 7. Fig. 7 is a flowchart showing details of the threshold setting process in Fig. 6.

[0140] First, in step S400, the microcomputer 170, as the first sound pressure determination unit, determines whether the value obtained by subtracting a threshold value from the collected sound pressure determination value is greater than a constant value N. The constant value N is a first predetermined value that is a predetermined positive value. The collected sound pressure determination value is the sound pressure value of the noise around the vehicle calculated in step S210 of FIG. 5.

[0141] At this time, in step S400, if the value obtained by subtracting the threshold value from the collected sound pressure judgment value is greater than the fixed value N, the microcomputer 170 makes a determination of YES.

[0142] Accordingly, in step S410, the microcomputer 170, functioning as the first counter control section, increments the count value (ie, the first count value) of the loud noise counter 172e (ie, the first counter) by one.

[0143] In addition, in step S420, the microcomputer 170 sets the count value of the small noise counter 172f (i.e., the second counter) in the memory 172 to zero. That is, the microcomputer 170 clears the count value of the small noise counter 172f.

[0144] In the next step S430, the microcomputer 170, as a first reference determination unit, determines whether the count value of the loud noise counter 172e is equal to or greater than a predetermined determined number of times (i.e., a first reference value). At this time, in step S430, the microcomputer 170 determines YES if the count value of the loud noise counter 172e is equal to or greater than the determined number of times.

[0145] Accordingly, in step S440, the microcomputer 170, functioning as the first threshold setting unit, increases the threshold by 1. Accordingly, in step S450, the microcomputer 170 sets the count value of the loud noise counter 172e to zero. That is, the microcomputer 170 clears the count value of the loud noise counter 172e and ends the threshold setting process.

[0146] If the count value of the loud noise counter 172e is less than the determined number in step S430, the microcomputer 170 determines NO and skips steps S440 and S450. Thereafter, the microcomputer 170 ends the threshold setting process.

[0147] In step S400, if the value obtained by subtracting the threshold value from the collected sound pressure determination value is equal to or less than a certain value N, the microcomputer 170 determines NO.

[0148] Accordingly, in step S460, the microcomputer 170, as a second sound pressure determination unit, determines whether or not the value obtained by subtracting the sound collection sound pressure determination value from the threshold value is greater than a constant value N. Here, the constant value N is a second predetermined value that is a predetermined positive value.

[0149] At this time, in step S460, if the value obtained by subtracting the collected sound pressure judgment value from the threshold value is greater than the fixed value N, the microcomputer 170 makes a YES determination.

[0150] Accordingly, the microcomputer 170, functioning as the second counter control section, increments the count value of the small noise counter 172f (i.e., the second count value) by one in step S470.

[0151] In addition, in step S480, the microcomputer 170 sets the count value of the loud noise counter 172e to zero. That is, the microcomputer 170 clears the count value of the loud noise counter 172e in the memory 172.

[0152] Next, in step S490, the microcomputer 170, as the second reference determination section, determines whether or not the count value of the small noise counter 172f is equal to or greater than a predetermined determined number of times (i.e., a second reference value).

[0153] At this time, the microcomputer 170 makes a YES determination in step S490 when the count value of the small noise counter 172f is equal to or greater than the determined number of times.

[0154] Accordingly, in step S500, the microcomputer 170, functioning as the second threshold setting unit, decreases the threshold by 1. Accordingly, in step S510, the microcomputer 170 sets the count value of the small noise counter 172f to zero. That is, the microcomputer 170 clears the count value of the small noise counter 172f in the memory 172 and ends the threshold setting process.

[0155] At this time, if the count value of the small noise counter 172f is less than the determined number of times in step S490, the microcomputer 170 determines NO. Accordingly, the microcomputer 170 skips steps S500 and S510 and ends the threshold setting process.

[0156] Furthermore, in step S460, the microcomputer 170 determines NO when the value obtained by subtracting the sound collection sound pressure judgment value from the threshold value is equal to or less than a certain value N. Accordingly, in step S520, the microcomputer 170 sets the count value of the loud noise counter 172e to zero.

[0157] That is, the microcomputer 170 clears the count value of the large noise counter 172 e. In addition, in step S530, the microcomputer 170 sets the count value of the small noise counter 172 f to zero. That is, the microcomputer 170 clears the count value of the small noise counter 172 f in the memory 172 and ends the threshold setting process.

[0158] The threshold setting process described above is repeatedly executed by the microcomputer 170 each time the sound collection sound pressure determination value is calculated in step S210. The microcomputer 170 increases the threshold by one each time it determines that the count value of the large noise counter 172e is equal to or greater than the determined number. On the other hand, the microcomputer 170 decreases the threshold by one each time it determines that the count value of the small noise counter 172f is equal to or greater than the determined number. The threshold may also be decreased by one when a state in which sound collection control is not being executed continues for a certain period of time.

[0159] The threshold signal indicating the threshold set by the microcomputer 170 in this manner is supplied to the inverting input terminal of the comparator 130. Therefore, the threshold is used to determine the level of the collected sound signal supplied from the preamplifier 120 to the comparator 130.

[0160] Next, details of the sound pressure control process performed by the microcomputer 170 in steps S320 and S360 in Fig. 6 or when an arbitrary sound generation request is received via the vehicle communication unit 150 will be described with reference to Fig. 8. Fig. 8 is a flowchart showing the sound pressure control process in detail.

[0161] In step S600, the microcomputer 170 prohibits the execution of sound collection control. That is, the microcomputer 170 prohibits the analog-to-digital converter 177 from converting the collected sound signal output from the preamplifier 120 into a digital signal.

[0162] Next, in step S610, the microcomputer 170 controls the power supply circuit 140 to connect the positive terminal of the in-vehicle battery Ba to the positive power supply terminal of the power amplifier 110. This starts the supply of power from the in-vehicle battery Ba to the power amplifier 110.

[0163] In the next step S620, the microcomputer 170 reads the sound source data selected in step S320 or step S360 from the memory 172. Alternatively, the microcomputer 170 reads from the memory 172 sound source data selected in response to an arbitrary sound generation request via the vehicle communication unit 150.

[0164] When the sound collected by the speaker 100 matches, for example, a command voice, the microcomputer 170 reads sound source data of the notification sound corresponding to the command voice from the sound source data group 172b pre-stored in the memory 172. Hereinafter, for convenience of explanation, the sound source data read from the memory 172 will be referred to as sound source data Sd.

[0165] Additionally, in step S620, the microcomputer 170 reads the collected sound pressure judgment value, the sound source data maximum sound pressure value 172c, and the prominent sound pressure 172d from the memory 172. Furthermore, in step S620, the microcomputer 170 reads the sound generator mounting position attenuation amount from the memory 300a of the exterior communication device 30 via the vehicle communication units 150 and 330.

[0166] Next, in step S630, the microcomputer 170 calculates the target sound pressure by adding the sound generator mounting position attenuation amount, the projecting sound pressure 172d, and the sound collection sound pressure judgment value. The target sound pressure is a target value of the sound pressure output from the speaker 100 when the microcomputer 170 generates sound from the speaker 100 based on the sound source data Sd.

[0167] Here, the target sound pressure is set so that the sound pressure output from the speaker 100 is greater than the sound pressure of the noise around the vehicle by the amount of projecting sound pressure 172d. The target sound pressure in this embodiment is calculated taking into account the sound generator mounting position attenuation, i.e., the amount of sound pressure attenuation due to the mounting position of the speaker 100.

[0168] Next, in the next steps S640 and S650, the microcomputer 170 calculates sound generation data Hx for generating sound from the speaker 100 at the target sound pressure based on the sound source data Sd.

[0169] Here, the sound source data Sd is digital data representing the waveform of a sound source signal to be generated from the speaker 100. The sound generation data Hx is digital data representing the signal waveform of a sound generation signal output from the digital-to-analog converter 175 to the power amplifier 110.

[0170] In order to make the sound pressure output from the speaker 100 equal to the target sound pressure, the microcomputer 170 multiplies the sound source data Sd (i.e., the amplitude of the sound source signal) by the volume coefficient Ko, and obtains this multiplied data as sound generation data Hx.

[0171] For example, the units of the sound source data maximum sound pressure value 172c and the target sound pressure are each assumed to be "dBSPL." 0 dB in "dBSPL" is 20 μ "Pa." The microcomputer 170 calculates the difference obtained by subtracting the sound source data maximum sound pressure value 172c from the target sound pressure as the sound pressure correction value HP "dB."

[0172] In other words, when the target sound pressure is smaller than the sound source data maximum sound pressure value 172c, the sound pressure correction value HP "dB" is a common logarithm that takes a negative value. On the other hand, when the target sound pressure is larger than the sound source data maximum sound pressure value 172c, the sound pressure correction value HP "dB" exceeds the sound generation capability of the vehicle sound generation device 10, and therefore the sound pressure correction value HP "dB" is a common logarithm with its upper limit set to zero.

[0173] The microcomputer 170 calculates the volume coefficient Ko by substituting the sound pressure correction value HP "dB" into Equation 1. Ko=10 (ＨＰ / ２０) In this way, the microcomputer 170 obtains the sound generation data Hx by multiplying the sound source data Sd by the volume coefficient Ko obtained from the sound pressure correction value HP.

[0174] Next, the microcomputer 170 converts the thus obtained sound generation data Hx into a sound generation signal by the digital-to-analog converter 175 and outputs the sound generation signal to the power amplifier 110. The sound generation signal is an analog signal for causing the sound source indicated by the sound source data Sd to be output from the speaker 100 at the target sound pressure.

[0175] The power amplifier 110 then power-amplifies the sound signal output from the microcomputer 170 and outputs the amplified sound to the speaker 100. The speaker 100 then outputs the sound (e.g., notification sound, voice, bird and animal repellent sound, warning sound, etc.) indicated by the sound source data Sd at the target sound pressure based on the output signal from the power amplifier 110. At this time, the sound pressure output from the speaker 100 is greater than the sound pressure of the noise around the vehicle by a protruding sound pressure 172d.

[0176] Thereafter, in step S660, the microcomputer 170 determines whether or not sound generation based on the sound source data Sd has ended.

[0177] At this time, the microcomputer 170 determines YES in step S660 when the generation of sound based on the sound source data Sd has ended. Accordingly, in step S670, the microcomputer 170 controls the power supply circuit 140 to disconnect the positive terminal of the vehicle battery Ba from the positive power supply terminal of the power amplifier 110. This stops the supply of power from the vehicle battery Ba to the power amplifier 110, and the output thereof becomes a high impedance state.

[0178] Next, in step S680, the microcomputer 170 transitions from the wake-up state to the sleep state and permits execution of sound collection control. That is, the microcomputer 170 permits the analog-to-digital converter 177 to convert the sound collection signal output from the preamplifier 120 into a digital signal in response to a sound collection request.

[0179] At this time, if no sound collection request is given to the microcomputer 170 from either of them, the microcomputer 170 goes into a sleep state.

[0180] At this time, the microcomputer 170 controls the power supply circuit 140 in conjunction with the operation cycle of the timer circuit 160. As a result, when the microcomputer 170 is in a sleep state, power is supplied from the power supply circuit 140 to the preamplifier 120 and the comparator 130 at regular intervals.

[0181] Therefore, the collected sound signal from the preamplifier 120 is input to the comparator 130 at regular intervals. Therefore, when the collected sound signal is not being input to the comparator 130, the power supply to the preamplifier 120 and the comparator 130 is stopped, thereby further reducing the dark current.

[0182] In this case, the wake-up determination in step S100 in Fig. 4 is performed when a sound collection signal is being input to the comparator 130. When the output signal from the comparator 130 exceeds the threshold value, the microcomputer 170 executes the sound collection control process in Fig. 5 as a sound collection request.

[0183] According to the present embodiment described above, the vehicle sound generation device 10 is equipped with a speaker 100 that is mounted on an automobile and has both a sound generation function of emitting sound toward the surroundings of the automobile and a sound collection function of outputting an output signal indicating sound collected from the surroundings of the automobile.

[0184] The sound generation device 10 for a vehicle includes a memory 172 and a microcomputer 170. The memory 172 stores a sound source data group 172b corresponding to sounds that satisfy predetermined sound generation conditions.

[0185] In step S310, the microcomputer 170 determines, based on the collected sound signal output from the speaker 100 via the preamplifier 120, whether or not the sound collected by the speaker 100 satisfies predetermined sound generation conditions.

[0186] When the microcomputer 170 determines that the sound collected by the speaker 100 satisfies the predetermined sound generation conditions, it makes a YES determination in step S310. Accordingly, the microcomputer 170 controls the speaker 100 to generate sound based on the sound source data Sd corresponding to the sound collected by the speaker 100, which is included in the sound source data group 172b.

[0187] Therefore, it is possible to provide a sound generation device 10 for a vehicle that spontaneously generates sound from the speaker 100 based on the sound collected by the speaker 100 .

[0188] In the present embodiment of the in-vehicle system 1 configured as above, the following operational effects (a), (b), (c), (d), (e), (f), (g), (h), (i), and (j) can be obtained.

[0189] (a) The microcomputer 170 calculates a collected sound pressure judgment value that indicates the sound pressure value of the noise around the vehicle, and based on this collected sound pressure judgment value, controls the speaker 100 so that the sound is emitted from the speaker 100 at a sound pressure that is greater than the sound pressure value of the noise around the vehicle but is not excessive.

[0190] This ensures that even if there are environmental sounds around the vehicle caused by traffic conditions such as vehicle running sounds, rain sounds, wind sounds, etc., the sound emitted from the speaker 100 can be reliably transmitted to people, cats, birds, etc. On the other hand, when the environmental sounds are small, they can be prevented from becoming noise.

[0191] (b) The microcomputer 170 determines whether the sound collected by the speaker 100 is an abnormality sound. When the microcomputer 170 determines that the sound collected by the speaker 100 is an abnormality sound, it requests the monitoring device 20 and the exterior communication device 30 to monitor the vehicle.

[0192] Therefore, based on the abnormal sound collected by the speaker 100, the monitoring device 20 can be made to record and monitor the surroundings of the vehicle automatically, and the vehicle can be linked to an external security system via the external communication device 30. This improves the security of the vehicle.

[0193] (c) When the microcomputer 170 determines that the sound picked up by the speaker 100 is a predetermined abnormality sound, it controls the speaker 100 to emit an alarm sound based on the sound source data corresponding to the abnormality sound.

[0194] Therefore, when a predetermined abnormality sound is picked up by the speaker 100, an alarm sound can be automatically emitted from the speaker 100. Therefore, by outputting the alarm sound around the vehicle, it is possible to keep people who may try to vandalize or steal the vehicle away from the vehicle.

[0195] (d) When the level of the collected sound signal output from the speaker 100 through the preamplifier 120 is less than the threshold value, the comparator 130 controls the microcomputer 170 to maintain the sleep state of the microcomputer 170.

[0196] Therefore, when the speaker 100 is not collecting the sound of the sound generation condition or the sound of the surrounding monitoring condition, the microcomputer 170 is maintained in a sleep state. This makes it possible to prevent an increase in power consumption by the microcomputer 170.

[0197] (e) The comparator 130 controls the microcomputer 170 to wake up when the level of the collected sound signal output from the speaker 100 through the preamplifier 120 is greater than a threshold value.

[0198] Therefore, the microcomputer 170 can execute the sound collection control process of Fig. 5. The microcomputer 170 can reliably perform sound generation, monitoring, reporting to the outside, and the like.

[0199] (f) When the speaker 100 finishes producing sound, the microcomputer 170 controls the power supply circuit 140 to stop the power supply to the power amplifier 110. Therefore, the operation of the power amplifier 110 is stopped, and power consumption by the power amplifier 110 can be reduced.

[0200] (g) In order to collect sound constantly or periodically, it is necessary to keep at least the microcomputer 170, which controls the analog-to-digital conversion, in a wake-up state. In this case, there is a problem that the current consumption of the microcomputer 170, i.e., the dark current, increases.

[0201] To address this issue, it is conceivable to combine hardware and software to be activated by a collected sound signal. However, this would create a new problem: the frequency at which the microcomputer 170 wakes up would change depending on the level of noise around the vehicle, making it difficult to reduce current consumption.

[0202] If it is desired to control the volume of the speaker 100 in conjunction with the sound pressure of the noise around the vehicle, it is conceivable to perform periodic sound collection control to follow changes in the situation around the vehicle. However, if the frequency of sound collection control is reduced in order to save current consumption, there is a problem in that the ability to follow the volume of the speaker 100 in conjunction with the sound pressure of the noise around the vehicle will be reduced.

[0203] In contrast to this, in this embodiment, the microcomputer 170 calculates a sound pressure judgment value by converting the level of the collected sound signal output from the speaker 100 through the preamplifier 120 into the pressure value of the sound collected by the speaker 100.

[0204] When the microcomputer 170 determines that the sound pressure determination value is greater than the threshold value, it increments the count value of the large noise counter 172 e. When the microcomputer 170 determines that the sound pressure determination value is smaller than the threshold value, it decrements the count value of the small noise counter 172 f.

[0205] Here, the microcomputer 170 adjusts the threshold value based on the count value of the large noise counter 172 e and the count value of the small noise counter 172 f. Therefore, when the noise around the vehicle increases, the threshold value is increased, and when the noise around the vehicle decreases, the threshold value is decreased.

[0206] This allows the wake-up sensitivity of the microcomputer 170 to be adjusted depending on the noise around the vehicle, thereby reducing the frequency with which the microcomputer 170 unnecessarily wakes up, thereby reducing the power consumption of the vehicle sound generation device 10.

[0207] (h) When the microcomputer 170 determines that the sound pressure judgment value is greater than the threshold value and that the value obtained by subtracting the threshold value from the sound pressure judgment value is equal to or greater than a certain value N, it increments the count value of the loud noise counter 172e by one.

[0208] When the microcomputer 170 determines that the sound pressure judgment value is smaller than the threshold value and that the value obtained by subtracting the sound pressure judgment value from the threshold value is larger than a fixed value N, it increments the count value of the small noise counter 172f by one.

[0209] Therefore, by using the constant value N, it is possible to set hysteresis to each of the changes in the count value of the large noise counter 172e and the changes in the count value of the small noise counter 172f. Accordingly, it is possible to set hysteresis to the threshold setting by the microcomputer 170, and by changing the setting when the judgments are consecutively consistent, it is possible to stabilize the control itself.

[0210] (i) When the sound collected by the speaker 100 is the cry of a cat or a bird, the microcomputer 170 causes the speaker 100 to emit a cat or bird repellent sound corresponding to the cry of a cat or a bird. This makes it possible to prevent cats, birds, etc. from invading the engine compartment of the automobile, building nests, and causing pollution such as feces and urine.

[0211] (j) The microcomputer 170 transmits a monitoring request to each of the monitoring device 20 and the exterior communication device 30. Thereafter, when the microcomputer 170 receives a sound generation request from at least one of the monitoring device 20 and the exterior communication device 30, it causes the speaker 100 to generate a warning sound. This ensures that a warning is issued to would-be thieves by voice in response to the sound generation requests from the monitoring device 20 and the exterior communication device 30.

[0212] Second Embodiment In the first embodiment, the microcomputer 170 emits a warning sound from the speaker 100 when receiving a sound emission request from at least one of the monitoring device 20 and the exterior communication device 30 .

[0213] However, instead of this, an example will be described with reference to Figure 9 in which the microcomputer 170 emits a warning sound from the speaker 100 when the characteristics of the sound collected by the speaker 100 match the sound characteristic data of the surrounding monitoring conditions.

[0214] 9 is a flowchart showing details of the sound collection type discrimination process by the microcomputer 170 of this embodiment. The microcomputer 170 executes the sound collection type discrimination process according to the flowchart of FIG.

[0215] Figure 9 includes step S360A instead of step S360 in Figure 6. In Figure 9, the same reference numerals as in Figure 6 indicate the same steps, and their explanations will be omitted. In step S330, the microcomputer 170 of this embodiment determines that the characteristics of the sound collected by the speaker 100 match the sound characteristic data of the surroundings monitoring conditions, and makes a YES determination.

[0216] Then, in step S360A, the microcomputer 170 selects, from the sound source data group 172b, sound source data for a warning sound that corresponds to the sound collected by the speaker 100. Thereafter, as in the first embodiment, the microcomputer 170 multiplies the selected sound source data Sd by the volume coefficient Ko to obtain sound generation data Hx, and converts the obtained sound generation data Hx into a sound generation signal by the digital-to-analog converter 175.

[0217] Accordingly, the power amplifier 110 amplifies the power of the sound signal output from the digital-to-analog converter 175 and outputs the amplified sound to the speaker 100. As a result, the speaker 100 generates a warning sound around the vehicle based on the output signal from the power amplifier 110.

[0218] Thereafter, in step S340, the microcomputer 170 transmits a monitoring request to each of the exterior communication device 30 and the monitoring device 20 via the vehicle communication unit 150, as in the first embodiment.

[0219] In the embodiment described above, when the characteristics of the sound collected by the speaker 100 match the sound characteristic data of the surrounding monitoring conditions, the microcomputer 170 causes the speaker 100 to emit a warning sound, without transmitting a monitoring request to the monitoring device 20 or the exterior communication device 30. Therefore, when it is determined that there is a suspicion of a thief stealing an automobile or automobile parts, the microcomputer 170 can immediately cause the speaker 100 to emit a warning sound to any thief around the automobile.

[0220] (Other embodiments)

[0221] (1) In the first and second embodiments, an example has been described in which the sound collection control process is executed by executing a computer program by the microcomputer 170. However, the present invention is not limited to this, and the sound collection control process may be executed by a hardware configuration using electronic circuits.

[0222] (2) In the first and second embodiments, an example has been described in which the sound collection type determination process is executed by executing a computer program by the microcomputer 170. However, the present invention is not limited to this, and the sound collection type determination process may be executed by a hardware configuration using electronic circuits.

[0223] (3) In the first and second embodiments, an example was described in which the threshold setting process was performed by executing a computer program by the microcomputer 170. However, this is not limiting, and the threshold setting process may be performed by a hardware configuration using electronic circuits.

[0224] (4) In the first and second embodiments, an example was described in which sound pressure control was performed by executing a computer program by the microcomputer 170. However, this is not limiting, and sound pressure control may be performed by a hardware configuration using electronic circuits.

[0225] (5) In the first and second embodiments, the microcomputer 170 causes the speaker 100 to emit a notification sound, a response sound, an auxiliary sound, a cat repellent sound, a bird repellent sound, a warning sound, an alarm sound, or the like.

[0226] However, this is not limiting, and in a situation where there is no problem with receiving voice commands through speaker 100, such as when the user present around the vehicle is authenticated using a smart key or the like, the following may be done.

[0227] That is, the microcomputer 170 outputs a response voice corresponding to the voice command collected and recognized by the speaker 100 from the speaker 100. Alternatively, the content of the voice command may be transferred to an external system.

[0228] (6) In implementing the vehicle sound generation device 10 of the present disclosure, the output signal of the preamplifier 120 may be used to monitor the operating state of the power amplifier 110. Here, when the speaker 100 is generating sound, the output of the power amplifier 110 has low impedance, and therefore no electrical signal is generated by the electromotive force of the speaker 100.

[0229] For this reason, the drive voltage output from the power amplifier 110 is input directly to the preamplifier 120. Therefore, when the speaker 100 is producing sound, the output signal of the preamplifier 120 is not used for analyzing or determining the collected sound signal, but may be used to monitor the operating state of the power amplifier 110.

[0230] (7) In the first and second embodiments, the microcomputer 170 transmits a monitoring request to an external system such as the monitoring device 20 or the external communication device 30 based on the sound collected by the speaker 100.

[0231] In addition, the microcomputer 170 can also issue a startup request to an external system based on the sound collected by the speaker 100. This makes it possible to select the necessary response, including cooperation with the external system, according to the type of sound collected by the speaker 100.

[0232] (8) In the first and second embodiments, an example was described in which the memory 172 was used to pre-record data such as feature data, sound source data, the maximum sound pressure value of the sound source data, and the prominent sound pressure. However, instead of this, data such as feature data, sound source data, the maximum sound pressure value of the sound source data, and the prominent sound pressure may be input to the central processing unit 171 from an external system via the vehicle communication unit 150.

[0233] (9) In the above first and second embodiments, an example was described in which the sound body mounting position attenuation amount is recorded in the memory 300a of the exterior communication device 30, and the sound body mounting position attenuation amount is input from the memory 300a to the microcomputer 170 via the vehicle communication unit 150.

[0234] However, instead of this, the sound generator mounting position attenuation amount may be stored in the memory of another external system. The sound generator mounting position attenuation amount may be input to the microcomputer 170 via the wireless circuit 310 and the vehicle communication units 330 and 150. Furthermore, if the sound generator mounting position attenuation amount is clear from the vehicle and its mounting environment, it may be recorded in advance in the memory 172 of the vehicle sound generation device 10.

[0235] (10) In the first and second embodiments, the microcomputer 170 may obtain the sound generation data Hx for generating sound at a target sound pressure from the speaker 100 based on the sound source data Sd as follows.

[0236] That is, the microcomputer 170 determines a coefficient to be multiplied by the sound source data Sd (i.e., the amplitude of the waveform of the sound source signal) based on the target sound pressure, and determines the value obtained by multiplying the sound source data Sd by the coefficient as the sound generation data Hx. The coefficient is set to a value greater than 1, and the higher the target sound pressure, the larger the value set for the coefficient. Therefore, the higher the target sound pressure, the larger the sound generation data Hx.

[0237] (11) In the first and second embodiments, the constant value N is set to a positive value in steps S400 and S460 of the threshold setting process in Fig. 7. However, instead of this, the constant value N may be set to zero.

[0238] (12) In the first and second embodiments, the digital-to-analog converter 175 and the analog-to-digital converter 177 are built into the microcomputer 170 .

[0239] In addition, however, the digital-to-analog converter 175 and the analog-to-digital converter 177 do not have to be built into the microcomputer 170. The digital-to-analog converter 175 and the analog-to-digital converter 177 can be selected depending on the required accuracy of the sound signal and the collected sound signal, respectively.

[0240] (13) In the first and second embodiments, the timer circuit 160 is configured independently of the microcomputer 170 .

[0241] However, instead of this, the timer circuit 160 may be one built into the microcomputer 170, and may continue to operate in the sleep state. The power supply control, sampling timing, and sound collection control time intervals of the preamplifier 120 and comparator 130 using the timer circuit 160 can be selected to correspond to the required reduction in current consumption.

[0242] (14) Note that the present disclosure is not limited to the above-described embodiments and can be modified as appropriate. Furthermore, the above-described embodiments are not unrelated to each other and can be combined as appropriate unless the combination is clearly impossible. Furthermore, in the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are considered to be clearly essential in principle. Furthermore, in the above-described embodiments, when numerical values ​​such as the number, numerical value, amount, and range of components of the embodiments are mentioned, they are not limited to the specific number unless they are specifically stated as essential or are clearly limited to a specific number in principle. Furthermore, in the above-described embodiments, when the shape, positional relationship, etc. of components, etc. are mentioned, they are not limited to the shape, positional relationship, etc. unless they are specifically stated or are limited to a specific shape, positional relationship, etc. in principle.

[0243] (Viewpoints of the Present Disclosure) The above-described present disclosure can be understood from the following viewpoints, for example.

[0244] [First Aspect] A sound generation device for a vehicle, comprising: a sound generation body (100) that is mounted on a vehicle and has both a sound generation function of generating sound toward the surroundings of the vehicle and a sound collection function of outputting an output signal indicating sound collected from the surroundings of the vehicle; a recording unit (172) in which sound source data corresponding to a predetermined sound is recorded; a sound collection determination unit (S310, S330) that determines whether the sound collected by the sound generation body is the predetermined sound based on the output signal output from the sound generation body; and a sound generation control unit (S320, S360A) that controls the sound generation body to generate sound from the sound generation body based on the sound source data recorded in the recording unit when the sound collection determination unit determines that the sound collected by the sound generation body is the predetermined sound.

[0245] [Second Aspect] The sound generation device for a vehicle according to the first aspect, further comprising a monitoring request unit (S340) that requests a monitoring device (20) that monitors the surroundings of the vehicle to monitor the surroundings of the vehicle, wherein, when the predetermined sound is an abnormality occurrence sound that occurs when an abnormality occurs in the vehicle, the sound collection determination unit (S330) determines whether the sound collected by the sound generation body is the abnormality occurrence sound, and when the sound collection determination unit determines that the sound collected by the sound generation body is the abnormality occurrence sound, the monitoring request unit requests the monitoring device to monitor the surroundings of the vehicle.

[0246] [Third Aspect] The vehicle sound generation device according to the first aspect, further comprising an external notification unit (S340) that controls a communication device (30) that issues a notification to the outside of the vehicle, wherein, when the predetermined sound is an abnormality occurrence sound that occurs when an abnormality occurs in the vehicle, the sound collection determination unit (S330) determines whether the sound collected by the sound generation body is the abnormality occurrence sound, and when the sound collection determination unit determines that the sound collected by the sound generation body is the abnormality occurrence sound, the external notification unit controls the communication device to notify the outside of the vehicle that an abnormality has occurred in the vehicle.

[0247] [Fourth Aspect] When the sound collection determination unit determines that the sound collected by the sound generator is the abnormality sound, the sound generation control unit (S360A) controls the sound generator to emit a warning sound based on the sound source data recorded in the recording unit. This is a sound generation device for a vehicle described in any one of the first to third aspects.

[0248] [Fifth Aspect] A sound generation device for a vehicle as described in any one of the first to fourth aspects, further comprising a noise calculation unit (S210) that calculates a sound pressure value of noise around the vehicle based on an output signal output from the sound generation body, and the sound generation control unit controls the sound generation body to generate sound at a sound pressure greater than the sound pressure value of the noise calculated by the noise calculation unit.

[0249] [Sixth Aspect] When the sound generation control unit is a first sound generation control unit, the vehicle sound generation device according to any one of the first to fifth aspects is provided with: a second sound generation control unit (S360) that controls the sound generation body to generate a warning sound when the sound generation control unit is a first sound generation control unit; and a sound generation request determination unit (S350) that determines whether or not generation of the warning sound is requested, wherein when the sound collection determination unit determines that the sound collected by the sound generation body is the abnormality sound and the sound generation request determination unit determines that generation of the warning sound is requested, the second sound generation control unit controls the sound generation body to generate the warning sound when the sound generation control unit determines that the sound collected by the sound generation body is the abnormality sound and the sound generation request determination unit determines that generation of the warning sound is requested.

[0250] [Seventh Aspect] A sound generation device for a vehicle as described in the sixth aspect, further comprising a noise calculation unit (S210) that calculates a sound pressure value of noise around the vehicle based on an output signal output from the sound generation unit, and the second sound generation control unit controls the sound generation unit to generate sound at a sound pressure greater than the sound pressure value of the noise calculated by the noise calculation unit.

[0251] [Eighth Aspect] A sound generation device for a vehicle according to any one of the first to seventh aspects, comprising: a microcomputer (170) that executes processing by the sound collection determination unit and processing by the sound generation control unit; and a startup control unit (S110) that controls the microcomputer to wake up from a sleep state when the level of the output signal from the sound generation body is greater than a threshold value.

[0252] [Ninth Aspect] A sound generating device for a vehicle according to the eighth aspect, comprising: a power amplifier (110) that controls the sound generating body so that a sound is generated from the sound generating body by power-amplifying a sound generating signal output from the microcomputer and outputting the power-amplified sound generating signal to the sound generating body; and a stop control unit (140) that stops the supply of power to the power amplifier to stop operation of the power amplifier when the microcomputer is in a sleep state.

[0253] [Tenth Aspect] A noise calculation unit (S210) that repeatedly calculates a sound pressure value of noise around the automobile based on an output signal output from the sound generator, a first sound pressure determination unit (S400) that determines whether the sound pressure value calculated by the noise calculation unit is greater than the threshold value each time the noise calculation unit calculates a sound pressure value, a first counter control unit (S410) that increases a count value of a first counter (172e) when the first sound pressure determination unit determines that the sound pressure value is greater than the threshold value, a second sound pressure determination unit (S460) that determines whether the sound pressure value calculated by the noise calculation unit is less than the threshold value, a second counter control unit (S470) that increases a count value of a second counter (172f) when the second sound pressure determination unit determines that the sound pressure value is less than the threshold value, and a first reference determination unit (S430) that determines whether the count value of the first counter is equal to or greater than a first reference value. a first threshold setting unit (S440) that increases the threshold when the first criterion determination unit determines that the count value of the first counter is equal to or greater than a first criterion value; a second criterion determination unit (S490) that determines whether the count value of the second counter is equal to or greater than a second criterion value; and a second threshold setting unit (S500) that decreases the threshold when the second criterion determination unit determines that the count value of the second counter is equal to or greater than the second criterion value.

[0254] [Eleventh Aspect] A noise calculation unit (S210) that repeatedly calculates a sound pressure value of noise around the automobile based on an output signal output from the sound generator, a first sound pressure determination unit (S400) that determines whether or not a value obtained by subtracting the threshold value from the sound pressure value calculated by the noise calculation unit is greater than a first predetermined value (N) each time the noise calculation unit calculates a sound pressure value, a first counter control unit (S410) that increases a count value of a first counter (172e) when the first sound pressure determination unit determines that the value obtained by subtracting the threshold value from the sound pressure value is greater than the first predetermined value (N), a second sound pressure determination unit (S460) that determines whether or not a value obtained by subtracting the sound pressure value from the threshold value is greater than a second predetermined value (N), and a second counter control unit (S470) that increases a count value of a second counter (172f) when the second sound pressure determination unit determines that the value obtained by subtracting the threshold value from the sound pressure value is greater than the second predetermined value. 9. The sound generation device for a vehicle according to claim 8, further comprising: a first criterion determination unit (S430) that determines whether the count value of the first counter is equal to or greater than a first criterion value; a first threshold setting unit (S440) that increases the threshold when the first criterion determination unit determines that the count value of the first counter is equal to or greater than the first criterion value; a second criterion determination unit (S490) that determines whether the count value of the second counter is equal to or greater than a second criterion value; and a second threshold setting unit (S500) that decreases the threshold when the second criterion determination unit determines that the count value of the second counter is equal to or greater than the second criterion value.

Claims

1. A sound generation device for a vehicle, comprising: a sound generation unit (100) that is mounted on a vehicle and has both a sound generation function of generating sound toward the surroundings of the vehicle and a sound collection function of outputting an output signal indicating sound collected from the surroundings of the vehicle; a recording unit (172) in which sound source data corresponding to a predetermined sound is recorded; a sound collection determination unit (S310, S330) that determines whether the sound collected by the sound generation unit is the predetermined sound based on the output signal output from the sound generation unit; and a sound generation control unit (S320, S360, S360A) that controls the sound generation unit to generate sound from the sound generation unit based on the sound source data recorded in the recording unit when the sound collection determination unit determines that the sound collected by the sound generation unit is the predetermined sound.

2. A sound generation device for a vehicle as described in claim 1, further comprising a monitoring request unit (S340) that requests a monitoring device (20) that monitors the surroundings of the vehicle to monitor the surroundings of the vehicle, wherein when the predetermined sound is an abnormality sound that occurs when an abnormality occurs in the vehicle, the sound collection determination unit (S330) determines whether the sound collected by the sound generation body is the abnormality sound, and when the sound collection determination unit determines that the sound collected by the sound generation body is the abnormality sound, the monitoring request unit requests the monitoring device to monitor the surroundings of the vehicle.

3. A sound generation device for a vehicle as described in claim 1, comprising an external notification unit (S340) that controls a communication device (30) that issues a notification to the outside of the vehicle, wherein, when the predetermined sound is an abnormality sound that occurs when an abnormality occurs in the vehicle, the sound collection determination unit (S330) determines whether the sound collected by the sound generation body is the abnormality sound, and when the sound collection determination unit determines that the sound collected by the sound generation body is the abnormality sound, the external notification unit controls the communication device to notify the outside of the vehicle that an abnormality has occurred in the vehicle.

4. A vehicle sound generation device as described in claim 2 or 3, wherein when the sound collection determination unit determines that the sound collected by the sound generation body is the abnormality sound, the sound generation control unit (S360A) controls the sound generation body to emit a warning sound based on the sound source data recorded in the recording unit.

5. A sound generation device for a vehicle as described in claim 1, further comprising a noise calculation unit (S210) that calculates the sound pressure value of the noise around the vehicle based on the output signal output from the sound generation unit, and the sound generation control unit controls the sound generation unit to generate sound at a sound pressure greater than the sound pressure value of the noise calculated by the noise calculation unit.

6. A sound generation device for a vehicle as described in claim 2 or 3, which comprises, when the sound generation control unit is a first sound generation control unit, a second sound generation control unit (S360) that controls the sound generation unit to generate a warning sound from the sound generation unit, and a sound generation request determination unit (S350) that determines whether or not generation of the warning sound is requested, wherein when the sound collection determination unit determines that the sound collected by the sound generation unit is the abnormality sound and the sound generation request determination unit determines that generation of the warning sound is requested, the second sound generation control unit controls the sound generation unit to generate the warning sound from the sound generation unit.

7. A sound generation device for a vehicle as described in claim 6, further comprising a noise calculation unit (S210) that calculates the sound pressure value of the noise around the vehicle based on the output signal output from the sound generation unit, and the second sound generation control unit controls the sound generation unit to generate sound at a sound pressure greater than the sound pressure value of the noise calculated by the noise calculation unit.

8. A sound generation device for a vehicle as described in claim 1, comprising: a microcomputer (170) that executes processing of the sound collection determination unit and processing of the sound generation control unit; and a startup control unit (S110) that controls the microcomputer to wake up from a sleep state when the level of the output signal from the sound generation body is greater than a threshold value.

9. A sound generating device for a vehicle as described in claim 8, comprising: a power amplifier (110) that controls the sound generating body so that a sound is generated from the sound generating body by power-amplifying a sound generating signal output from the microcomputer and outputting the power-amplified sound generating signal to the sound generating body; and a stop control unit (140) that stops the supply of power to the power amplifier to stop the operation of the power amplifier when the microcomputer is in a sleep state.

10. A noise calculation unit (S210) that repeatedly calculates a sound pressure value of noise around the automobile based on an output signal output from the sound generator, a first sound pressure determination unit (S400) that determines whether the sound pressure value calculated by the noise calculation unit is greater than the threshold value each time the noise calculation unit calculates a sound pressure value, a first counter control unit (S410) that increases the count value of a first counter (172e) when the first sound pressure determination unit determines that the sound pressure value is greater than the threshold value, a second sound pressure determination unit (S460) that determines whether the sound pressure value calculated by the noise calculation unit is less than the threshold value, a second counter control unit (S470) that increases the count value of a second counter (172f) when the second sound pressure determination unit determines that the sound pressure value is less than the threshold value, and a first reference determination unit (S430) that determines whether the count value of the first counter is equal to or greater than a first reference value.

9. The sound generation device for a vehicle according to claim 8, further comprising: a first threshold setting unit (S440) that increases the threshold when the first criterion determination unit determines that the count value of the first counter is equal to or greater than a first reference value; a second criterion determination unit (S490) that determines whether the count value of the second counter is equal to or greater than a second reference value; and a second threshold setting unit (S500) that decreases the threshold when the second criterion determination unit determines that the count value of the second counter is equal to or greater than the second reference value.

11. A noise calculation unit (S210) that repeatedly calculates a sound pressure value of noise around the automobile based on an output signal output from the sound generator, a first sound pressure determination unit (S400) that determines whether or not a value obtained by subtracting the threshold value from the sound pressure value calculated by the noise calculation unit is greater than a first predetermined value (N) each time the noise calculation unit calculates a sound pressure value, a first counter control unit (S410) that increases a count value of a first counter (172e) when the first sound pressure determination unit determines that the value obtained by subtracting the threshold value from the sound pressure value is greater than the first predetermined value (N), a second sound pressure determination unit (S460) that determines whether or not a value obtained by subtracting the sound pressure value from the threshold value is greater than a second predetermined value (N), and a second counter control unit (S470) that increases a count value of a second counter (172f) when the second sound pressure determination unit determines that the value obtained by subtracting the threshold value from the sound pressure value is greater than the second predetermined value.

9. The sound generation device for a vehicle according to claim 8, further comprising: a first criterion determination unit (S430) that determines whether the count value of the first counter is equal to or greater than a first criterion value; a first threshold setting unit (S440) that increases the threshold when the first criterion determination unit determines that the count value of the first counter is equal to or greater than the first criterion value; a second criterion determination unit (S490) that determines whether the count value of the second counter is equal to or greater than a second criterion value; and a second threshold setting unit (S500) that decreases the threshold when the second criterion determination unit determines that the count value of the second counter is equal to or greater than the second criterion value.

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