Notification device

Abstract

The present invention provides a notification device capable of appropriately notifying an occupant while suppressing a decrease in entertainment in a vehicle. A notification device for performing notification by emitting a sound into a passenger compartment of a vehicle is provided with: a speaker for emitting a sound into the passenger compartment; a microphone provided in the vehicle, the microphone converting the collected sound into a sound signal and outputting the sound signal; and a control device that causes the speaker to output sound on the basis of the sound signal, the control device: acquiring content sound information relating to content sound of in-vehicle entertainment; acquiring notice sound information for generating a notice calling sound for calling notice; estimating a driving state of the vehicle based on the sound signal acquired by the microphone; setting the volume of each of the content sound and the attention sound on the basis of the estimated driving state; on the basis of the content sound information and the attention sound information, the speaker outputs the corresponding content sound and attention sound at the set volumes, respectively.

Description

Technical Field

[0001] The present invention relates to a notification device mounted on a vehicle and used for providing notification by sound. Background Art

[0002] In recent years, efforts have been underway to develop sustainable transportation systems that are responsive to the needs of vulnerable road users, such as the elderly, people with disabilities, and children. To achieve this, research and development of passenger notification technologies has become crucial as a means of further improving traffic safety.

[0003] Driving assistance devices that provide advance warning to the driver of a vehicle are known (e.g., Patent Document 1). The driving assistance device disclosed in Patent Document 1 detects objects located in the intended direction of travel, such as the left or right turn, at an intersection where there is a possibility of a right or left turn on the intended route, and issues a warning with a warning sound.

[0004] In the driving assistance device of Patent Document 1, a sound heard from a real object, such as a vehicle engine sound or road noise, is generated from a virtual sound source as an attention-inducing sound. The volume is set to a level that does not interfere with conversation or music.

[0005] To warn and alert passengers, a known vehicle attention-calling device is installed in a vehicle seat and includes a vibrating device that applies vibration to the passenger (e.g., Patent Document 2). The vibrating device is installed on the seat back and seat cushion. The vibrating device on the seat back is positioned near the passenger's shoulders and shoulder blades, while the vibrating device on the seat cushion is positioned near the passenger's buttocks and legs.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent No. 5867171

[0009] Patent Document 2: Japanese Patent Application Publication No. 2019-116221 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] However, with the recent trend toward IT in vehicles, increasing emphasis on cabin comfort has led to increasingly sophisticated in-car entertainment systems, including car audio systems. Furthermore, ensuring vehicle safety requires appropriate warnings and alerts to passengers, particularly the driver, who are enjoying in-car entertainment.

[0012] In the driving assistance device of Patent Document 1, the attention-calling sound is set to a level that does not interfere with conversation and music. Therefore, when strong attention-calling is required from the driver, there is a possibility that the driver's attention may not be sufficiently called.

[0013] In the vehicle attention-calling device of Patent Document 2, the vibration generated by the vibrating device may not be effectively transmitted to the driver depending on the driver's physique and posture.

[0014] In view of the above background, the present invention aims to provide a notification device that can suppress the reduction of in-car entertainment and appropriately notify passengers, and further improve traffic safety and contribute to the development of a sustainable transportation system.

[0015] Means for solving problems

[0016] In order to solve the above-mentioned problems, one solution of the present invention is a notification device 9, which makes notifications by emitting sound into the passenger compartment 1S of the vehicle 1, and the notification device 9 comprises: a speaker 23, which emits sound into the passenger compartment; a microphone 25, which is arranged in the vehicle, and the microphone converts the collected sound into a sound signal and outputs it; and a control device 27, which, based on the sound signal, causes the speaker to output sound, and the control device performs the following processing: obtains content sound information related to the content sound of in-car entertainment; obtains attention sound information for generating an attention-calling sound, which is used to call attention; estimates the driving state of the vehicle based on the sound signal obtained by the microphone; sets the respective volumes of the content sound and the attention-calling sound based on the estimated driving state; and causes the speaker to output the corresponding content sound and the attention-calling sound at the set volumes based on the content sound information and the attention sound information.

[0017] According to this method, the volume of the content sound and the attention-calling sound can be set according to the vehicle's driving state. Therefore, it is possible to determine whether to call attention based on the vehicle's driving state and set the volume appropriately, thereby providing a notification device that can appropriately notify passengers without reducing in-vehicle entertainment.

[0018] In the above scheme, preferably, the control device sets an attention level indicating the degree of attention required of the occupant based on the sound signal acquired by the microphone, and reduces the volume of the sound generated from the speaker based on the content sound information as the attention level becomes higher.

[0019] According to this aspect, as the level of attention required of the occupant increases, the volume of the content sound decreases. This prevents the occupant from having difficulty hearing the attention-calling sound due to the content sound when attention is required.

[0020] In the above aspect, preferably, the control device increases the volume of the sound generated from the speaker based on the warning sound information as the warning level becomes higher.

[0021] According to this aspect, as the level of attention required of the occupant increases, the volume of the attention-calling sound based on the attention sound information increases. This makes it easier for the occupant to hear the attention-calling sound when attention is required, and thus allows the occupant to be appropriately informed.

[0022] In the above aspect, preferably, a vibration device 31 is included that generates vibrations for notifying the occupant, and the control device drives the vibration device based on the estimated driving state.

[0023] According to this aspect, the occupant can be notified by the vibration device.

[0024] In the above aspect, preferably, when the warning level is equal to or lower than a predetermined threshold value, the control device stops outputting the sound based on the warning sound information and drives the vibration device.

[0025] According to this aspect, when the caution level is below the threshold, the vibration device is driven to stop outputting the sound based on the caution sound information. This allows the occupants to be informed without reducing the in-vehicle entertainment.

[0026] In the above-mentioned technical solution, preferably, when the attention level is greater than a predetermined threshold value, the control device increases the volume based on the attention sound information as the attention level becomes higher.

[0027] According to this aspect, when the level of attention required of the occupant becomes higher, the volume of the attention-calling sound becomes higher. Thus, when attention is required, the occupant can easily hear the attention-calling sound, and thus the occupant can be appropriately informed.

[0028] In the above aspect, preferably, a vibration device 31 is included, which generates vibrations to notify the occupant, and the control device increases the amplitude of the vibrations generated by the vibration device as the attention level becomes higher.

[0029] According to this aspect, as the level of attention required of the occupant increases, the amplitude of the vibration generated by the vibration device increases. This makes it easier for the occupant to feel the vibration when attention is required, and thus allows the occupant to be appropriately informed.

[0030] In the above scheme, preferably, the control device estimates whether the vehicle is driving in the rain based on the sound signal obtained by the microphone, and when it is determined that the vehicle is driving in the rain, sets the attention level to be higher than when it is determined that the vehicle is not driving in the rain.

[0031] According to this aspect, the caution level is set to be higher when driving in rainy weather, which requires caution, than when driving in rainy weather is not being performed. Therefore, the caution level can be set appropriately.

[0032] In the above-mentioned scheme, preferably, when the control device determines that the vehicle is not driving in the rain, based on the sound signal obtained by the microphone, determines whether the vehicle is driving at high speed, and when it is determined that the vehicle is driving at high speed, sets the attention level to be higher than when it is determined that the vehicle is not driving at high speed.

[0033] According to this aspect, when the vehicle is traveling at a high speed, for which caution should be called, the caution level is set higher than when the vehicle is not traveling at a high speed, so that the caution level can be set appropriately.

[0034] Effects of the Invention

[0035] According to the above aspect, it is possible to provide a notification device that can appropriately notify the occupant without reducing the in-vehicle entertainment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic diagram showing a vehicle equipped with a notification device.

[0037] Figure 2 This is a functional block diagram of a vehicle equipped with a notification device.

[0038] Figure 3 This is an example of the intensity of the sound signal collected by the microphone when it rains.

[0039] Figure 4 This is a flowchart of the output setting process.

[0040] Figure 5 This is a table showing the relationship between the driving state and the corresponding warning level and amplification factor settings.

[0041] Figure 6 This is a flowchart of the driving state estimation process.

[0042] Description of Reference Numerals

[0043] 1: Vehicle

[0044] 1S: Carriage (passenger compartment)

[0045] 9: Sound system (notification device)

[0046] 23: Speaker

[0047] 25: Microphone

[0048] 27: Output control device (control device)

[0049] 31: Vibration device DETAILED DESCRIPTION

[0050] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0051] like Figure 1 As shown, the notification device of the present invention is mounted on a vehicle such as an automobile, and performs notification by emitting sound into the passenger compartment (ie, the cabin) of the vehicle.

[0052] like Figure 1 as well as Figure 2 As shown, vehicle 1 is equipped with: an attention-calling system 3 that generates information related to attention-calling; a navigation system 5 that generates information related to driving guidance; a content acquisition system 7 that generates information for playing music and broadcast sounds within vehicle cabin 1S; and an audio system 9 that generates sounds within vehicle cabin 1S for notification based on information from attention-calling system 3, navigation system 5, and content acquisition system 7. In this embodiment, audio system 9 can provide notifications to passengers not only through sound but also through vibration.

[0053] The attention-calling system 3 generates information (attention sound information) for producing a sound (attention-calling sound) to call the occupants' attention based on various conditions, such as the surrounding conditions of the vehicle 1. The attention-calling system 3 includes at least one sensing device 11 and an alarm generating device 13 that generates the information for calling attention based on the detection results of the sensing device 11.

[0054] The sensing device 11 may be a radar 11A, a laser radar 11B, a sonar 11C, or a camera 11D that captures the front, rear, left, and right sides of the vehicle 1. Furthermore, the sensing device 11 may be one or more sensors that detect information related to the driver. Specifically, for example, the sensing device 11 may be a sensor that detects biological information such as the driver's heart rate and respiratory rate. Alternatively, the sensing device 11 may be a camera that detects the driver from the front to monitor drowsiness.

[0055] The alarm generating device 13 is constituted by a computer including a processor 13A and a storage device 13B. The processor 13A of the alarm generating device 13 determines whether it is necessary to call the attention of the occupant based on the detection result of the sensing device 11.

[0056] Specifically, if the sensing device 11 includes, for example, a radar 11A, a laser radar 11B, or a sonar 11C, the alarm generating device 13 (processor 13A) acquires information related to surrounding vehicles, pedestrians, obstacles, and the like. Based on this acquired information and the distance from the vehicle 1 in which the vehicle is located, the alarm generating device 13 determines whether the driver's attention should be called. For example, if the distance between a surrounding object located behind the vehicle 1 is below a predetermined threshold, the alarm generating device 13 determines that an attention-calling sound should be issued, generates attention sound information indicating the corresponding attention-calling sound, and outputs it to the audio system 9.

[0057] Furthermore, the alarm generating device 13 generates information necessary for calling attention (attention-calling information) based on the detection results of the sensing device 11, and outputs it to the audio system 9, etc. The attention-calling information may include, in addition to the attention sound information, information regarding the form of vibration to be output by the audio system 9 (also referred to as attention vibration information). The attention vibration information may include various information necessary for outputting vibration, such as the timing, location, amplitude, and frequency of the vibration.

[0058] The navigation system 5 searches for a travel route to a set destination, and generates information for displaying the route obtained by the search and information related to voice for guiding the driver regarding the obtained route.

[0059] The navigation system 5 includes a position detection device 15 and a guidance processing device 17 .

[0060] The position detection device 15 determines the current position of the vehicle 1 by a known method and outputs information indicating the determined current position to the guidance processing device 17. The position detection device 15 may be formed of, for example, a GPS receiver that receives signals from GPS satellites to determine the position of the vehicle 1.

[0061] The guidance processing device 17 is comprised of a computer equipped with a processor 17A, such as a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit), various types of memory (not shown), such as volatile memory and non-volatile memory, and a storage device 17B storing map information. The guidance processing device 17 searches for a driving route from the current position of the vehicle 1, as determined by the position detection device 15, and the map information stored in the storage device 17B. The guidance processing device 17 outputs information (guidance image information) for displaying the searched route on a display device and a signal (guidance audio information) for providing guidance to the driver on the route found through the search, to the audio system 9. Hereinafter, the guidance image information and guidance audio information will be collectively referred to as guidance information.

[0062] The content acquisition system 7 acquires information for providing in-vehicle entertainment to passengers, such as music playback, radio reception, and movie playback. The content acquisition system 7 acquires information related to entertainment content such as music, radio, and movies, generates a signal corresponding to the sound to be output (content sound information), and outputs this signal to the audio system 9.

[0063] The content acquisition system 7 outputs a signal corresponding to sound for playing music or video and a signal corresponding to video to the audio system 9 in order to provide in-car entertainment to the passengers.

[0064] The content acquisition system 7 can be composed of a computer including a content acquisition device 19 and a content processing device 21. For example, the content acquisition device 19 can be composed of various media reading devices that read content information related to music or video from various media such as CDs (Compact Discs) or DVDs (Digital Versatile Discs). The content processing device 21 can also be composed of a processor 21A that processes content information. The content acquisition device 19 can also be equipped with various memories such as volatile memories and non-volatile memories. The content acquisition system 7 (specifically, the processor 21A) generates information corresponding to the sound to be output (hereinafter referred to as content sound information. It is also called a signal corresponding to the sound) and information corresponding to the video (content video information. It is also called a signal corresponding to the video) based on the content information acquired by the content acquisition device 19, and outputs it to the audio system 9. Hereinafter, the content sound information and the content video information are collectively recorded as content information.

[0065] The content acquisition device 19 may also be configured to download content information from various servers via a mobile communication network and store it in a storage device such as a memory, an SSD, or an HDD. Furthermore, the content acquisition device 19 may generate a signal corresponding to the sound to be output (i.e., content audio information) and a signal corresponding to the video based on content information such as radio programs and television programs received from a receiver (not shown) of radio broadcast waves and television broadcast waves, and output these to the audio system 9.

[0066] The audio system 9 includes at least one speaker 23, at least one microphone 25, and an output control device 27. In this embodiment, the audio system 9 includes a display device 29 and a vibration device 31 in addition to the speaker 23, the microphone 25, and the output control device 27.

[0067] The speaker 23 is installed on a wall defining the vehicle interior 1S, a seat headrest, etc., and emits sound toward the interior of the vehicle interior 1S. When the speaker 23 is installed on a wall defining the vehicle interior 1S, such as a door interior, it can be fixed so that the direction of sound emission (also called sound emission direction) faces toward the vehicle interior.

[0068] The speakers 23 are connected to the output control device 27 via wiring such as audio cables. Signals are supplied to the speakers 23 from the output control device 27. When a signal is supplied from the output control device 27, the speakers 23 emit a sound corresponding to the signal into the vehicle cabin 1S.

[0069] The sounds emitted from the speaker 23 may include three types of sounds: sounds corresponding to the attention sound information generated by the attention calling system 3 , sounds corresponding to the guidance sound information generated by the navigation system 5 , and sounds corresponding to the content sound information generated by the content acquisition system 7 .

[0070] The microphone 25 (also referred to as a microphone) is mounted on the vehicle 1 and collects sounds inside or outside the vehicle cabin 1S and converts them into electrical signals (sound signals). The microphone 25 can be installed outside the vehicle cabin 1S or inside the vehicle cabin 1S. For example, the microphone 25 can be installed on the roof (ceiling) near the driver's seat.

[0071] The microphone 25 is configured to collect sounds inside the vehicle cabin 1S and sounds outside the vehicle (hereinafter referred to as "external sounds"). Examples of external sounds collected by the microphone 25 include the sound of rain around the vehicle 1, wind noise caused by the vehicle 1 traveling at high speeds, road noise caused by the vehicle 1 traveling (hereinafter referred to as "road noise"), and noise caused by construction work around the vehicle 1.

[0072] Rain noise, wind noise, and road noise have properties corresponding to the main causes of sound generation. For example, in the case of rain noise, the sound is generated when raindrops reach the vehicle 1. Therefore, Figure 3 As shown, when driving in the rain, a peak-shaped peak representing the sound of raindrops occurs in the sound pressure of the sound collected by the microphone 25 (corresponding to the square of the amplitude of the sound signal detected by the microphone 25, or the intensity of the sound signal) (see Figure 3 Road noise has the following characteristics: it contains many frequency components below 1 kHz, and wind noise contains many frequency components above 500 Hz.

[0073] like Figure 1 As shown, the microphone 25 is connected to the output control device 27 via a wire harness (signal line). The microphone 25 converts the collected sound into a sound signal and outputs the converted sound signal to the output control device 27.

[0074] like Figure 1 as well as Figure 2 As shown, the display device 29 is provided at a position within the vehicle compartment 1S where passengers can visually recognize the information, and notifies the passengers of visual information by displaying a screen. The display device 29 may be formed of a touch panel display or the like. The display device 29 can display content information such as map information and routes output by the navigation system 5, and videos acquired by the content acquisition system 7. The display device 29 is connected to the output control device 27 via a wiring harness (signal line) and displays the screen based on signals from the output control device 27. In addition, when the display device 29 is formed of a touch panel display, the display device 29 outputs information related to the operation input to the screen to the output control device 27.

[0075] The vibration device 31 notifies the occupant through tactile stimulation. The vibration device 31 can be formed of a well-known vibration device using, for example, an eccentric motor, a linear resonance actuator, or the like.

[0076] The vibration device 31 can also be provided on a seat provided in the vehicle compartment 1S, for example. In this case, the vibration device 31 can be provided at any position as long as it is in a position to transmit vibration to the occupant seated on the seat, for example, it can be provided on the back side of the seat back or the back side of the seating surface of the seat cushion. When provided on the seat back, the vibration device 31 can be configured near the shoulders or shoulder blades of the occupant seated on the seat. When provided on the seat cushion, the vibration device 31 can be provided near the buttocks or legs of the occupant. The vibration device 31 is connected to the output control device 27 via a wiring harness (signal line), and the amplitude and frequency of the vibration output by the vibration device 31 are controlled by the output control device 27.

[0077] Furthermore, the vibration device 31 may be provided on a steering wheel held by a driver, thereby enabling notification to be given to the driver who is holding the steering wheel for driving.

[0078] The output control device 27 is composed of one or more electronic control units (ECUs) including a processor 33 such as a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit), a volatile memory 35, a non-volatile memory 37, and a storage device 39 such as an SSD (Solid State Drive) or an HDD (Hard Disk Drive).

[0079] The output control device 27 may also include an A / D converter 41 for digitally processing the sound signal from the microphone 25, and a D / A converter 43 for outputting sound from the speaker 23 and / or outputting vibrations from the vibration device 31. Furthermore, the output control device 27 may also include an amplifier 45 for amplifying the output from the D / A converter 43. The processor 33 can set the amplification factor (also known as gain) corresponding to each of the warning sound information, the guidance sound information, and the content sound information, and thereby set the volume of the corresponding sound.

[0080] The output control device 27 is connected to the attention calling system 3, the navigation system 5, and the content acquisition system 7 via a harness (signal line). The output control device 27 acquires attention calling information from the attention calling system 3, guidance information from the navigation system 5, and content information from the content acquisition system 7.

[0081] When the output control device 27 receives attention sound information, guidance sound information, and content sound information, it amplifies the corresponding sounds (attention-calling sound, guidance sound, and content sound) at a predetermined amplification factor, synthesizes them (also called mixing), and emits them from the speaker 23. When the output control device 27 receives guidance image information, content video information, etc., it causes the display device 29 to display the corresponding screens.

[0082] Upon receiving the content sound information and warning sound information, the output control device 27 performs an output setting process to set the amplification factor corresponding to each sound based on the driving state of the vehicle 1. The amplification factor, also known as gain, refers to the ratio of the output to the input to the output control device 27. The amplification factor set during the output setting process can range from a value less than 1 (i.e., attenuation, negative gain) to 0 (i.e., silencing the corresponding sound).

[0083] In the present embodiment, the output control device 27 sets the amplification factor corresponding to each sound signal and also sets the amplification factor for the amplitude of the vibration output from the vibration device 31 . Figure 4The following is a flowchart showing the output setting process of this embodiment. Figure 4 The output setting process executed by the output control device 27 will be described in detail with reference to the flowchart of the output setting process shown in FIG.

[0084] In the first step ST1 of the output setting process, the output control device 27 estimates the driving state of the vehicle 1 based on the sound signal acquired from the microphone 25 and acquires the attention level (ST1). The attention level indicates the degree of attention required of the occupants (particularly the driver). As the attention level increases, the degree of attention required of the occupants increases, and more careful driving operations are required of the driver.

[0085] exist Figure 5 A table showing the relationship between the driving state and the corresponding caution level in this embodiment is shown in . Hereinafter, the driving state of the vehicle 1 may include the driving mode of the vehicle 1 such as the speed and acceleration of the vehicle 1 and the conditions around the vehicle 1 .

[0086] exist Figure 5 In the illustrated example, the estimated driving states include a rainy driving state in which the vehicle 1 is driving in heavy rain, a high-speed driving state in which the vehicle 1 is traveling at a high speed, and a normal driving state in which the vehicle 1 is traveling at a normal speed and noise is detected due to construction work being carried out around the vehicle 1. The caution level is set to 3 (high) in the rainy driving state, 2 (medium) in the high-speed driving state, and 1 (low) in the normal driving state. When the caution level is acquired, the output control device 27 executes step ST2.

[0087] In step ST2, the output control device 27 refers to the warning level obtained in step ST1. Figure 5 The table shown in FIG. 1 sets the amplification rate of the sound corresponding to the attention sound information (i.e., the attention-calling sound). When the attention level obtained by the output control device 27 in ST1 is 3 (driving state in rainy weather), the amplification rate of the attention-calling sound is set to a specified value greater than 1 times (for example, 1.5 times, etc.). When the attention level obtained by the output control device 27 in ST1 is 2 (high-speed driving state), the amplification rate of the attention-calling sound is set to 1 times. When the attention level obtained by the output control device 27 in ST1 is 1 (normal driving state), the amplification rate of the attention-calling sound is set to 0 times (i.e., the stop attention-calling sound). When the setting of the amplification rate of the sound corresponding to the attention sound information is completed, the output control device 27 executes step ST3.

[0088] In step ST3, the output control device 27 refers to the warning level obtained in ST1. Figure 5The output control device 27 sets the amplification factor of the driving amount of the vibration device 31 according to the table shown in FIG. When the caution level obtained in ST1 is 3 (driving in rainy weather) or 2 (driving at high speed), the output control device 27 sets the amplification factor of the driving amount of the vibration device 31 to a predetermined value greater than 1 (e.g., 1.5 times). When the caution level obtained in ST1 is 1 (normal driving), the output control device 27 sets the amplification factor to 1. When the setting of the amplification factor of the driving amount of the vibration device 31 is completed, the output control device 27 executes step ST4.

[0089] In step ST4, the output control device 27 refers to the warning level obtained in ST1. Figure 5 The table shown sets the amplification factor for the sound corresponding to the content sound information (i.e., the content sound). When the caution level obtained in ST1 is 3 (driving in rainy weather), the output control device 27 sets the amplification factor for the content sound to a value less than 1 (i.e., a negative gain), for example, 0.5. When the caution level obtained in ST1 is 2 (high-speed driving) or 1 (normal driving), the output control device 27 sets the amplification factor for the content sound to 1. Once the amplification factor corresponding to the content sound is set, the output control device 27 terminates the output setting process.

[0090] The output control device 27 amplifies the attention-calling sound and the content sound at corresponding amplification factors based on the acquired attention sound information and content sound information and the amplification factors set by the output setting process, synthesizes (mixes, also called superimposes), and outputs them from the speaker 23.

[0091] Furthermore, in this embodiment, the output control device 27 sets the amplification factor for the sound corresponding to the guidance sound information (i.e., the guidance sound) to the same value as the amplification factor for the attention-calling sound during the output setting process. However, the output control device 27 may also set the amplification factor for the guidance sound to be smaller than the amplification factor for the attention-calling sound and larger than the amplification factor for the content sound during the output setting process.

[0092] like Figure 5 As shown, in step ST1 of the output setting process, the output control device 27 estimates the driving state based on the output of the microphone 25, thereby acquiring the attention level. Figure 6 FIG. 2 shows an example of a flowchart of a process for estimating a driving state, that is, a driving state estimation process, performed by the output control device 27. Figure 6 An example of the traveling state estimation process shown in FIG.

[0093] In the initial step ST11 of the driving state determination process, the output control device 27 estimates the presence and severity of rain based on the sound signal output from the microphone 25. Specifically, the output control device 27 counts the number of raindrop sounds (spikes) within a predetermined time period based on the sound signal output from the microphone 25. If the number of raindrop sounds per unit time exceeds a predetermined threshold, the output control device 27 proceeds to step ST12, whereupon the output control device 27 determines that the driving state is rainy, terminating the driving state estimation process. If the microphone 25 does not detect raindrop sounds, or if the raindrop sounds are less than the predetermined threshold, the output control device 27 determines that the driving state is not rainy, and proceeds to step ST13.

[0094] In step ST13, the output control device 27 determines whether the proportion of sound signals caused by wind noise in the sound signal acquired by the microphone 25 is greater than a predetermined threshold. In this embodiment, the output control device 27 first removes the sound signal due to raindrops from the sound signal acquired by the microphone 25 by performing known signal processing. For example, the output control device 27 may remove the spike-like sound signal due to raindrops by performing known filtering on the sound signal acquired by the microphone 25. Alternatively, the output control device 27 may remove the sound signal corresponding to the spike sound due to raindrops by removing the sound signal for a predetermined time width centered around the peak of the spike-like sound signal due to raindrops. Next, the output control device 27 performs frequency analysis on the sound signal after removing the sound signal due to raindrops to calculate the proportion of sound signals with frequencies greater than a predetermined frequency threshold (e.g., 500 Hz). If the proportion of these sound signals exceeds the predetermined threshold, the output control device 27 determines that the proportion of sound signals due to wind noise is greater than the predetermined threshold.

[0095] If the output control device 27 determines that the proportion of the sound signal due to wind noise is greater than or equal to the predetermined threshold, it determines that the driving state is in the high-speed driving state (step ST14), and the driving state estimation process ends. If the output control device 27 determines that the proportion of the sound signal due to wind noise is not greater than or equal to the predetermined threshold, it determines that the driving state is in the normal driving state (step ST15), and the driving state estimation process ends.

[0096] Next, the operation and effects of the thus configured acoustic system 9 will be described.

[0097] like Figure 5As shown, the output control device 27 sets the amplification factors, i.e., the volumes, corresponding to the content sound and the attention-calling sound, respectively, based on the driving state of the vehicle 1 estimated in step ST1, and generates the content sound and the attention-calling sound from the speaker 23. Thus, the audio system 9 functions as a notification device that generates the attention-calling sound and emits it into the passenger compartment of the vehicle 1 to provide notification.

[0098] like Figure 5 As shown, output control device 27 estimates the driving state of vehicle 1 based on the sound picked up by microphone 25. For example, output control device 27 estimates that vehicle 1 is driving in rainy conditions based on the sound of rain picked up by microphone 25. If output control device 27 determines that vehicle 1 is not driving in rainy conditions, it then determines whether vehicle 1 is driving at high speed based on the intensity of wind noise. In this way, by using the sound picked up by microphone 25, the driving state of vehicle 1 can be appropriately and easily acquired.

[0099] like Figure 5 As shown, the output control device 27 sets the amplification factor of the content sound to be smaller when the caution level is 3 (driving in rainy weather) than when the caution level is 2 (driving at high speed). Thus, when the caution level changes from 2 to 3, the volume of the sound generated by the microphone 25 based on the content sound information, i.e., the content sound, becomes smaller.

[0100] Therefore, when the vehicle changes from a high-speed driving state to a rainy driving state with a high level of caution, the volume of the content sound is reduced. This prevents the occupant from having difficulty hearing the attention-calling sound due to the content sound when the vehicle requires attention.

[0101] Furthermore, the output control device 27 is configured to increase the amplification factor of the attention-calling sound as the attention level increases when the attention level is 2 or higher. Thus, as the attention level increases from 2 to 3, the volume of the sound generated by the microphone 25 based on the attention sound information, i.e., the attention-calling sound, increases.

[0102] As a result, when the attention is requested, the occupant can easily hear the attention calling sound, and thus the occupant can be appropriately informed.

[0103] In addition, if Figure 5 As shown, when the attention level is 1 or lower, that is, when the vehicle 1 is in normal driving, the output control device 27 sets the amplification factor of the attention-calling sound to 0 and stops outputting the attention-calling sound. Simultaneously, the output control device 27 sets the amplification factor of the vibration device 31 to 1, activates the vibration device 31, and notifies the occupants.

[0104] Thus, when the attention level falls below a predetermined threshold (in this embodiment, the threshold is 1), the vibration device 31 is driven to perform a vibration notification instead of stopping the output of the attention-calling sound. This maintains the volume of the content sound during the notification, allowing the occupants to be appropriately notified without reducing the in-vehicle entertainment experience.

[0105] Furthermore, when the attention level is 2 or lower, the output control device 27 increases the amplitude of the vibration generated by the vibration device 31 as the attention level increases. Therefore, as the attention level changes from 1 (normal driving state) to 2 (high-speed driving state), and the level of attention required of the occupant increases, the amplitude of the vibration generated by the vibration device 31 increases. This makes it easier for the occupant to feel the vibration when attention is required, allowing the occupant to be appropriately informed.

[0106] In this way, the audio system 9 can set the volume of the content sound and the attention-calling sound according to the driving state of the vehicle 1. Therefore, the volume of the content sound and the attention-calling sound can be set according to the degree of attention required. This allows the audio system 9 to appropriately inform passengers without compromising the in-vehicle entertainment experience.

[0107] Thus, according to the present disclosure, a notification device (sound system 9) is provided that can appropriately notify passengers without reducing in-car entertainment. The notification device (sound system 9) of the present disclosure is expected to further improve traffic safety and contribute to the development of a sustainable transportation system.

[0108] The above concludes the description of the specific embodiment, but the present invention is not limited to the above-described embodiment and modifications, and can be implemented in a wide variety of modifications.

[0109] exist Figure 5 In the embodiment shown, the output control device 27 controls the output of the warning level when the warning level is higher than the predetermined threshold value (in Figure 5 (in the case of a threshold of 2 or greater), the amplification factor of the attention-calling sound is set to increase as the attention level increases, but this is not the only setting. Specifically, the output control device 27 can also be set to increase the amplification factor of the attention-calling sound as the attention level increases, independent of the threshold, and to decrease the volume of the content sound as the attention level increases. In this case, as the level of attention required of the occupant increases, the volume of the content sound also decreases. This prevents the occupant from having difficulty hearing the attention-calling sound due to the content sound when attention is required.

[0110] In the above embodiment, the output control device 27 is configured to estimate the driving state of the vehicle 1 through the microphone 25, but it can also be configured to estimate the driving state of the vehicle 1 based on the output of the sensing device 11 such as the radar 11A, the laser radar 11B, the sonar 11C, the camera 11D, and the output of various sensors such as the vehicle speed sensor and the acceleration sensor installed on the vehicle body in addition to the microphone 25.

[0111] In the above embodiment, an example is described in which the alarm generating device 13, the guidance processing device 17, the content processing device 21 and the output control device 27 are separately constructed, but the present invention is not limited to this method. The alarm generating device 13, the guidance processing device 17, the content processing device 21 and the output control device 27 can also be constructed by a single processing device.

[0112] Furthermore, in the above embodiment, the caution level is set higher than in normal driving conditions when driving in rainy weather or at high speeds, but the present invention is not limited to this embodiment. For example, the caution level may be set higher than in normal driving conditions when microphone 25 detects rumbling sounds, roars caused by strong winds or lightning strikes, or warning sounds issued by local authorities.

Claims

1. A notification device that makes a notification by emitting a sound into a passenger compartment of a vehicle, wherein: The notification device comprises: a speaker that emits sound into the passenger compartment; a microphone, which is disposed on the vehicle and converts the collected sound into a sound signal for output; and a control device that causes the speaker to output sound based on the sound signal, The control device performs the following processing: Acquiring content audio information related to content audio of in-car entertainment; Acquiring attention sound information for generating an attention-calling sound, wherein the attention-calling sound is used to call attention; estimating a driving state of the vehicle based on the sound signal acquired by the microphone; setting the volume of each of the content sound and the attention-calling sound based on the estimated driving state; Based on the content sound information and the attention sound information, the speaker is caused to output the corresponding content sound and attention calling sound at set volumes, respectively.

2. The notification device according to claim 1, wherein: The control device sets an attention level indicating a degree of attention required of an occupant based on the sound signal acquired by the microphone, and reduces the volume of the sound generated from the speaker based on the content sound information as the attention level becomes higher.

3. The notification device according to claim 2, wherein: The control device increases the volume of the sound generated from the speaker based on the warning sound information as the warning level becomes higher.

4. The notification device according to claim 2, wherein: The notification device includes a vibration device that generates vibrations to notify the occupant. The control device drives the vibration device based on the estimated running state.

5. The notification device according to claim 4, wherein: When the warning level is equal to or lower than a predetermined threshold, the control device stops outputting the sound based on the warning sound information and drives the vibration device.

6. The notification device according to claim 2, wherein: When the attention level is greater than a predetermined threshold, the control device increases the volume based on the attention sound information as the attention level becomes higher.

7. The notification device according to claim 6, wherein: The notification device includes a vibration device that generates vibrations to notify the occupant. The control device increases the amplitude of the vibration generated by the vibration device as the attention level becomes higher.

8. The notification device according to any one of claims 2 to 6, wherein: The control device estimates whether the vehicle is currently driving in the rain based on the sound signal acquired by the microphone, and sets the caution level higher when it is determined that the vehicle is currently driving in the rain than when it is determined that the vehicle is not currently driving in the rain.

9. The notification device according to claim 8, wherein: When the control device determines that the vehicle is not driving in rainy weather, the control device determines whether the vehicle is driving at a high speed based on the sound signal obtained by the microphone, and when it is determined that the vehicle is driving at a high speed, the control device sets the attention level to be higher than when it is determined that the vehicle is not driving at a high speed.

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