JP6540763B2 - Vehicle interior sound field evaluation device, vehicle interior sound field evaluation method, vehicle interior sound field control device, and indoor sound field evaluation device - Google Patents

Description

  The present invention relates to a car interior sound field evaluation device and a car interior sound field evaluation method for evaluating a sound field in a car interior, a car interior sound field control device for controlling a sound field in a car interior, and a room sound field in a mobile unit. The present invention relates to a room sound field evaluation device to be evaluated.

  In a vehicle such as a car, various sounds are generated in the vehicle compartment by sounds transmitted from the outside of the vehicle compartment to the vehicle compartment such as engine noise and road noise, and the comfort of the occupant in the vehicle compartment is impaired. In order to improve comfort, it is required to improve the quietness of the cabin.

  In order to improve the quietness of the cabin, it is considered effective to evaluate the sound field in the cabin and control the sound field in the cabin according to the evaluation result. However, the quietness of the cabin It is difficult to appropriately evaluate the sound field in the passenger compartment as to the quietness of the passenger compartment, because is evaluated by the human sense based on the human auditory characteristics. For example, Patent Document 1 discloses an event detection device that detects an event such as a rhythm or a tempo from an audio signal in consideration of human auditory characteristics, although this does not evaluate a sound field in a vehicle compartment.

JP 2005-257708 A

  Conventionally, in the case of evaluating a sound field, it has been performed based on frequency characteristics of sound in consideration of human auditory characteristics. Moreover, in recent years, it is also known to create and evaluate a visual saliency map based on frequency characteristics and time characteristics of sound from a spectrogram. However, as described above, since the quietness of the cabin is evaluated by human sense based on the human auditory characteristics, it is difficult to appropriately evaluate the sound field in the cabin for the quietness of the cabin, and it is difficult to It is desirable to accurately evaluate the sound field in a room.

  The inventors of the present invention have repeatedly conducted various researches and studies, and as a result, the sensory evaluation of the quietness of the cabin by the human sense based on the human auditory characteristics and the spatial distribution feature of the sound field in the cabin are highly correlated. It was found that the higher the uniformity of the space distribution, the higher the sensory evaluation of the quietness of the cabin. According to such knowledge, it is considered that the sound field in the vehicle compartment can be evaluated with high accuracy for the quietness of the vehicle compartment based on the spatial distribution feature of the sound field in the vehicle compartment.

  In addition, if it is possible to properly evaluate the sound field in the vehicle compartment about the quietness of the vehicle compartment based on the spatial distribution feature of the sound field in the vehicle compartment, the evaluation result of the sound field in the vehicle compartment about the quietness of the vehicle compartment By controlling the sound field in the cabin based on the above, it is considered that the quietness of the cabin can be improved.

  This is not limited to a vehicle as a moving body, but similarly for the room in other moving bodies, based on the spatial distribution feature of the sound field in the room of the moving body It is considered that the sound field in the room of the moving body can be accurately evaluated.

  Then, this invention makes it a basic object to evaluate the sound field of a vehicle interior accurately about the quietness of a vehicle interior, and to improve the silence of a vehicle interior effectively.

  In order to solve the above-mentioned subject, the present invention is characterized by having constituted as follows.

  First, the invention according to claim 1 of the present application is a vehicle interior sound field evaluation apparatus for evaluating a sound field in a vehicle interior, which is detected by a sound detection unit for detecting a sound in the vehicle interior and the sound detection unit. Space distribution feature extraction unit for extracting the space distribution feature of the sound field in the vehicle interior by extracting the space distribution feature of the virtual sound source including the strength of the virtual sound source based on the sound in the vehicle interior; And a sound field evaluation unit which evaluates the sound field in the vehicle compartment about the quietness of the vehicle compartment based on the spatial distribution feature of the sound field in the vehicle compartment extracted by the above.

  In the second aspect of the invention, in the invention according to the first aspect, the spatial distribution feature extraction unit determines the strength of the virtual sound source based on the sound in the vehicle compartment detected by the sound detection unit. Extracting a spatial distribution feature of the virtual sound source to include a feature map of the spatial distribution feature of the sound field in the vehicle compartment, and the sound field evaluation unit is a feature of the spatial distribution feature generated by the spatial distribution feature extraction unit The saliency map of the spatial distribution feature of the sound field in the vehicle compartment is created based on the map, and the sound field in the passenger compartment is evaluated for silence in the cabin based on the saliency map of the spatial distribution feature. Do.

  Also, in the invention according to claim 3, in the invention according to claim 1, the space distribution feature extraction unit is not limited to the space sensitivity characteristic of the sound in the vehicle compartment detected by the sound detection unit and human hearing. It is characterized in that the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on which the spatial distribution feature of the sound field in the vehicle compartment is extracted.

  In the invention described in claim 4, in the invention described in any one of claims 1 to 3, a sound field in the vehicle compartment based on the sound in the vehicle compartment detected by the sound detection unit. And a time feature extraction unit for extracting a time feature of a sound field in the vehicle compartment based on the sound in the vehicle compartment detected by the sound detection unit; The evaluation unit extracts the spatial distribution feature of the sound field in the vehicle compartment extracted by the spatial distribution feature extractor, the frequency feature of the sound field in the vehicle compartment extracted by the frequency feature extractor, and the temporal feature extractor And evaluating the sound field in the vehicle cabin for the quietness of the vehicle room based on the time characteristics of the sound field in the vehicle cabin.

  The invention according to claim 5 is a vehicle interior sound field evaluation method for evaluating a sound field in a vehicle interior, comprising: a sound detection step of detecting a sound in the vehicle interior; and a vehicle detected by the sound detection step. Spatial distribution feature extraction step of extracting spatial distribution feature of sound field in vehicle interior by extracting spatial distribution feature of virtual sound source including strength of virtual sound source based on indoor sound, and extracted by the spatial distribution feature extraction step And a sound field evaluation step of evaluating the sound field in the vehicle compartment about the quietness of the vehicle compartment based on the spatial distribution feature of the sound field in the vehicle compartment.

  The invention according to claim 6 is a vehicle interior sound field control apparatus for controlling a sound field in a vehicle interior, comprising: a sound detection unit detecting a sound in the vehicle interior; and a vehicle detected by the sound detection unit A spatial distribution feature extraction unit for extracting spatial distribution features of a sound field in a vehicle interior by extracting spatial distribution features of a virtual sound source including the strength of a virtual sound source based on indoor sound, and extraction by the spatial distribution feature extraction unit A sound field evaluation unit that evaluates the sound field in the vehicle cabin about the quietness of the vehicle room based on the spatial distribution feature of the sound field in the vehicle cabin, and the noise performance of the vehicle cabin evaluated by the sound field evaluation unit And a sound field control unit that controls a sound field in the vehicle compartment based on an evaluation result of a sound field in the vehicle compartment.

  The invention according to claim 7 is an indoor sound field evaluation apparatus for evaluating a sound field in a room of a moving body, which is detected by a sound detection unit which detects a sound in the room of the moving body, and the sound detection unit. A spatial distribution feature extraction unit that extracts spatial distribution features of the virtual sound source including the strength of the virtual sound source based on the indoor sound of the moving object, and extracts spatial distribution characteristics of the sound field in the room of the moving object; A sound field evaluation unit that evaluates the sound field in the room of the moving body for the quietness of the room of the moving body based on the space distribution feature of the sound field in the room of the moving body extracted by the space distribution feature extraction unit; It is characterized by

  According to the first aspect of the present invention, the sound in the vehicle compartment is detected, and the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on the sound in the vehicle compartment to detect the sound field in the vehicle compartment. The spatial distribution feature of the vehicle interior is extracted, and the sound field in the vehicle interior is evaluated for the quietness of the vehicle interior based on the spatial distribution feature of the sound field in the vehicle interior.

  Thereby, a virtual sound source including the strength of a virtual sound source, specifically, the spatial distribution feature of the sound field in the passenger compartment having correlation with the sensory evaluation of the quietness of the passenger compartment by human sense based on human auditory characteristics Since the sound field in the vehicle compartment is evaluated for the quietness of the vehicle compartment based on the spatial distribution feature of the above, it is possible to accurately evaluate the quietness of the vehicle compartment. Assess the quietness of the cabin is higher as the uniformity of the spatial distribution of the virtual sound source including the strength of the virtual sound source is higher, so that the quietness of the cabin can be accurately evaluated in consideration of the human auditory characteristics. Can.

  According to the second aspect of the present invention, the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on the sound in the vehicle compartment, and the feature map of the spatial distribution feature of the sound field in the vehicle interior is extracted. By creating a saliency map based on the feature map and evaluating the sound field in the cabin for the quietness of the cabin based on the saliency map, the silence of the cabin using the saliency map It can evaluate quantitatively and can acquire the said effect effectively.

  Further, according to the invention described in claim 3, the space distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on the sound in the car room and the space sensitivity characteristic in human hearing. By extracting the spatial distribution feature of the vehicle, it is possible to more accurately evaluate the quietness of the passenger compartment in consideration of the spatial sensitivity in human hearing.

  Further, according to the invention described in claim 4, frequency characteristics and time characteristics of the sound field in the vehicle compartment are extracted based on the sound in the vehicle compartment, and spatial distribution characteristics, frequency features and time of the sound field in the vehicle compartment By evaluating the sound field in the passenger compartment for the quietness of the passenger compartment based on the features, the passenger compartment's silence in consideration of frequency characteristics and time characteristics in addition to the spatial distribution characteristic of the sound field in the passenger compartment Can be evaluated, and the effect can be obtained more effectively.

  Further, according to the invention of claim 5, the sound in the vehicle compartment is detected, and the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on the sound in the vehicle compartment and the sound field in the vehicle compartment The spatial distribution feature of the vehicle is extracted, and the sound field in the vehicle cabin is evaluated for the quietness of the vehicle cabin based on the spatial distribution feature.

  Thereby, a virtual sound source including the strength of a virtual sound source, specifically, the spatial distribution feature of the sound field in the passenger compartment having correlation with the sensory evaluation of the quietness of the passenger compartment by human sense based on human auditory characteristics Since the sound field in the vehicle compartment is evaluated for the quietness of the vehicle compartment based on the spatial distribution feature of the above, it is possible to accurately evaluate the quietness of the vehicle compartment. Assess the quietness of the cabin is higher as the uniformity of the spatial distribution of the virtual sound source including the strength of the virtual sound source is higher, so that the quietness of the cabin can be accurately evaluated in consideration of the human auditory characteristics. Can.

  Further, according to the invention described in claim 6, the sound in the vehicle compartment is detected, and the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on the sound in the vehicle compartment and the sound field in the vehicle compartment The spatial distribution feature of the vehicle is extracted, the sound field of the vehicle compartment is evaluated about the quietness of the vehicle compartment based on the spatial distribution feature of the sound field in the vehicle compartment, and the evaluation result of the sound field of the vehicle compartment about the quietness of the vehicle compartment Control the sound field in the cabin based on.

  Thereby, a virtual sound source including the strength of a virtual sound source, specifically, the spatial distribution feature of the sound field in the passenger compartment having correlation with the sensory evaluation of the quietness of the passenger compartment by human sense based on human auditory characteristics Since the sound field in the vehicle compartment is evaluated for the quietness of the vehicle compartment based on the spatial distribution feature of the above, it is possible to accurately evaluate the quietness of the vehicle compartment. And since the sound field in a vehicle interior is controlled based on the evaluation result of the sound field in the vehicle interior about the quietness of the vehicle interior evaluated with sufficient accuracy, the quietness of a vehicle interior can be improved effectively. By controlling the sound field in the vehicle compartment so as to cancel the sound in the vehicle compartment based on the evaluation result of the sound field in the vehicle compartment about the quietness of the vehicle compartment, the quietness of the vehicle compartment can be effectively improved. .

  Further, according to the invention described in claim 7, the sound of the room of the moving body is detected, and the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted and moved based on the sound of the room of the moving body. The spatial distribution feature of the sound field in the room of the body is extracted, and the sound field in the room of the moving body is evaluated for the quietness of the room of the moving body based on the spatial distribution feature of the sound field in the room.

  Thereby, the spatial distribution feature of the sound field in the room of the moving body having correlation with the sensory evaluation of the quietness of the room of the moving body by the human sense based on the human auditory characteristics, specifically the strength of the virtual sound source Since the sound field in the room of the moving body is evaluated for the quietness of the room of the moving body based on the spatial distribution feature of the virtual sound source including the above, it is possible to accurately evaluate the quietness of the room of the moving body. It is evaluated that the quietness of the room of the moving body is higher as the uniformity of the spatial distribution of the virtual sound source including the strength of the virtual sound source is higher, and the accuracy of the quietness of the room of the moving body is taken into consideration It can be evaluated well.

It is a graph which shows the detection result of the sound pressure of the sound in the vehicle interior at the time of impulse sound generation | occurrence | production. It is a figure which shows space distribution of the virtual sound source containing the strength of a virtual sound source. It is the figure which cut | disconnected the cross section orthogonal to Z direction about space distribution of the virtual sound source shown in FIG. It is explanatory drawing for demonstrating a polar coordinate system. It is an image which shows space distribution of a virtual sound source including the intensity of the virtual sound source which considered the space sensitivity characteristic in human auditory sense. It is a saliency map of the spatial distribution feature of the sound field in the passenger compartment. It is a figure which shows a spectrogram. It is a saliency map of the frequency feature of the sound field in the passenger compartment. It is a saliency map of the time feature of the sound field in the passenger compartment. It is a graph which shows the space distribution feature of the sound field in a vehicle interior, the frequency feature, and the saliency level of each time feature. It is a graph which shows the total of the space distribution feature of the sound field in a vehicle interior, the frequency feature, and the saliency level of a time feature. It is a block diagram which shows the structure of the vehicle interior sound field evaluation apparatus which concerns on embodiment of this invention. It is a flowchart which shows evaluation processing control of a vehicle interior sound field evaluation apparatus. It is a flow chart which shows extraction processing of space distribution feature. It is a flow chart which shows extraction processing of a frequency feature. It is a flow chart which shows extraction processing of time feature. It is a flowchart which shows the evaluation process of the sound field in a vehicle interior. FIG. 1 is a block diagram showing a configuration of a vehicle interior sound field control device according to an embodiment of the present invention. It is a flowchart which shows sound field process control of a vehicle interior sound field control apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the attached drawings.

  In order to evaluate the sound field in the passenger compartment for the quietness of the passenger compartment, the present inventors first performed a sensory evaluation for the passenger compartment's quietness based on human senses based on human auditory characteristics. An evaluation meeting consisting of multiple members was set up, and at this evaluation meeting, a sensory evaluation was conducted on the quietness of the cabin for multiple car models, specifically three car models A, B and C. . And the result of the sensory evaluation that the quietness of a compartment becomes high in order of a vehicle type A, a vehicle type B, and a vehicle type C was obtained.

  In addition, for the three vehicle types A, B, and C, sensory evaluation of the quietness of the vehicle compartment by human sense based on human auditory characteristics, multiple characteristics of the sound field in the vehicle interior, specifically, spatial distribution feature A saliency map (prominence map) was created and examined for correlation with frequency characteristics and time characteristics.

  When creating the spatial distribution feature, frequency feature and temporal feature map of the sound field in the passenger compartment, for each of the three vehicle types A, B and C, the headrest of the passenger seat in the vicinity of the ear of the occupant seated in the passenger seat A microphone is installed as a sound detection unit (sound detection sensor) for detecting a sound in the vehicle compartment, and a speaker is installed as a sound output unit (sound output device) for outputting a sound to the rear seat.

  The microphone is configured to detect the sound pressure of the sound in the vehicle compartment and to detect the particle velocity in the vehicle longitudinal direction, the vehicle width direction, and the vehicle vertical direction. The speaker is configured to output a sound. The microphone and the speaker are connected to a control unit (not shown). The control unit is configured around a computer, and a display device such as a display is connected to the control unit.

  Then, an impulse sound is generated from the speaker, the sound in the vehicle compartment is detected by the microphone, and the spatial distribution feature, the frequency feature and the time feature of the sound field in the vehicle compartment are extracted based on the detected sound in the vehicle compartment. A saliency map of spatial distribution feature, frequency feature and temporal feature of the sound field in the room was created.

  FIG. 1 is a graph showing the result of detection of the sound pressure of the sound in the passenger compartment when an impulse sound is generated. In FIG. 1, the sound pressure is shown on the vertical axis, and the time is shown on the horizontal axis. An impulse sound was generated from the speaker, and as shown in FIG. 1, a time-dependent change in the sound pressure of the sound in the passenger compartment was detected by the microphone.

  Further, when the impulse sound is generated, the particle velocity of the sound in the vehicle interior, specifically, the particle velocity in the vehicle longitudinal direction, the vehicle width direction and the vehicle vertical direction is detected by the microphone. With the microphone as a reference, the longitudinal direction of the vehicle is X, the lateral direction is Y, and the vertical direction is Z. The forward side of the vehicle is positive in the X direction, and the right side of the vehicle is positive in the Y direction. Is the positive side in the Z direction.

The creation of a saliency map of the spatial distribution feature of the sound field in the passenger compartment will be described.
First, based on the sound pressure of sound in the vehicle compartment detected at the time of impulse sound generation and the particle velocity in the X direction, Y direction and Z direction, the sound pressure and particle velocity in each direction at each time from the time of impulse sound generation The product was calculated as the sound strength in each direction, and the square root of the sum of the squares of the sound strength in each direction was calculated as the total sound strength.

For example, at time _{t 1} from when the impulse sound generation, calculates the product of the sound pressure Pt ₁ and X direction of the particle velocity Vxt ₁ as strength IXT ₁ in the X direction of the sound, the sound pressure Pt ₁ and Y directions The product of particle velocity Vyt ₁ is calculated as sound intensity Iyt ₁ in the Y direction, and the product of sound pressure Pt ₁ and particle velocity Vzt ₁ in the Z direction is calculated as sound intensity Izt _{1 in the} Z direction. The square root of the sum of squares of the sound intensity in each direction {{(Ixt ₁ ) ² + (Iyt ₁ ) ² + (Izt ₁ ) ² } was calculated as the sound intensity It ₁ . Similarly, the intensity of the sound in each direction and the intensity of the entire sound were calculated for each time from the generation of the impulse sound.

  In addition, from the particle velocity in the X, Y, and Z directions at each time from when the impulse sound is generated, the direction of the virtual sound source considered to be the sound source of the sound detected by the microphone at each time is calculated The product of each time from time and the sound speed was calculated as the distance from the microphone to the virtual sound source, and the position of the virtual sound source of the sound detected by the microphone at each time was calculated. The position of the virtual sound source was calculated on the assumption that the sound from the virtual sound source was sequentially detected by the microphone.

For example, with respect to a virtual sound source of sound detected at time t ₁ from the time of impulse sound generation, based on particle velocity Vxt ₁ , Vyt ₁ , Vzt _{1 at} time t _{1 with} X direction, Y direction, Z direction The X direction component, Y direction component and Z direction component of the virtual sound source are calculated as (-Vxt ₁ , -Vyt ₁ , -Vzt ₁ ) and the product of time t ₁ and sound speed c is the distance from the microphone to the virtual sound source The position of the virtual sound source is calculated as (t ₁ × c) · (−Vxt ₁ , −Vyt ₁ , −Vzt ₁ ) / √ {(− Vxt ₁ ) ² + (− Vxt ₁ ) ² + (− Vxt ₁₎ Calculated as ² ). The position of the virtual sound source was similarly calculated for each time from when the impulse sound was generated.

  FIG. 2 is a diagram showing the spatial distribution of the virtual sound source including the strength of the virtual sound source. In FIG. 2, the position of the virtual sound source is displayed as a black circle (●) in the rectangular coordinate system based on the microphone, and the strength of the virtual sound source is displayed as the size of the black circle, and the strength of the virtual sound source is large It is displayed so large. Assuming that the overall sound strength calculated based on the sound in the passenger compartment is the strength of the virtual sound source, the strength of the virtual sound source and the position of the virtual sound source are calculated, and as shown in FIG. We calculated the spatial distribution of the virtual sound source including the strength of.

  FIG. 3 is a cross-sectional view of the space distribution of the virtual sound source shown in FIG. 2 which is orthogonal to the Z direction. In FIG. 3, the position of the virtual sound source is displayed as a black circle and the strength of the virtual sound source is displayed as the size of the black circle in the XY coordinate system based on the microphone, and the larger the strength of the virtual sound source, the larger the display doing. Although FIG. 3 shows the XY coordinate system in order to facilitate understanding of the spatial distribution of the virtual sound source including the strength of the virtual sound source, as shown in FIG. We calculated the spatial distribution of the included virtual sound source.

  Then, the spatial distribution of the virtual sound source including the strength of the virtual sound source in the XYZ coordinate system is projected onto a unit spherical surface based on the microphone, and the spatial distribution of the virtual sound source including the strength of the virtual sound source is calculated for the unit spherical surface. For each virtual sound source, only the position of the virtual sound source is projected on the unit spherical surface, and the strength of the virtual sound source is the strength of the original virtual sound source.

For example, in a virtual sound source of sound detected at time t ₁ from the time of impulse sound generation, the position of the virtual sound source projected on the unit spherical surface is (−Vxt ₁ , −Vyt ₁ , −Vzt ₁ ) / √ {(− ^{_{Vxt 1) 2 + (- Vxt}} 1) 2 + (- calculated as _Vxt ^{1) 2}.} The position of the virtual sound source projected onto the unit spherical surface was similarly calculated for each time from when the impulse sound was generated.

Next, the space distribution of the virtual sound source including the strength of the virtual sound source projected on the unit spherical surface was coordinate-transformed from the orthogonal coordinate system to the polar coordinate system.
FIG. 4 is an explanatory view for explaining a polar coordinate system. As shown in FIG. 4, in the orthogonal plane orthogonal to the Z direction based on the microphone, the direction from the positive side in the X direction to the negative side in the Y direction is taken as a positive azimuth angle φ and from the orthogonal plane to the Z direction Coordinate conversion was performed to a polar coordinate system in which the direction toward the positive side is a positive elevation angle θ.

  The spatial distribution of the virtual sound source including the strength of the virtual sound source projected onto the unit spherical surface is subjected to coordinate sensitivity conversion from the orthogonal coordinate system to the polar coordinate system, and then the strength of each virtual sound source is taken into consideration. The spatial distribution of the virtual sound source, including the strength of the virtual sound source, was calculated taking into account the spatial sensitivity characteristics of human hearing by multiplying the space sensitivity coefficient of human hearing by.

  The spatial sensitivity in the actual human auditory sense is high directly in front of a human with an azimuthal angle φ and an elevation angle θ of zero degrees, and low in a human's true back where the azimuthal angle φ is 180 degrees or -180 degrees and the elevation angle is zero degree The elevation angle is 90 degrees or -90 degrees above or below a human being, which is lower than the front and higher than the rear, and differs depending on the direction of the sound source.

  The spatial sensitivity characteristics of human hearing are considered to decrease functionally from the front to the back of the human body in accordance with the cosine function, and the sensory evaluation of the quietness of the cabin and the spatial distribution of the sound field in the cabin When investigating correlations with features, frequency features, and time features, the spatial sensitivity factor in human hearing is set to 1 directly in front of human beings and 0.5 in human's true back surface, directly upon human beings It is set as what is functionally reduced according to the cosine function from the to the back.

  FIG. 5 is an image showing a spatial distribution of a virtual sound source including the strength of the virtual sound source in consideration of the spatial sensitivity characteristic in human hearing. In FIG. 5, with regard to the spatial distribution of the virtual sound source including the strength of the virtual sound source in the unit spherical surface coordinate-transformed to the polar coordinate system, the space in human hearing in which the strength of each virtual sound source is multiplied by the space sensitivity coefficient in human hearing. The image of the spatial distribution of the virtual sound source including the strength of the virtual sound source in consideration of the sensitivity characteristic is shown.

  In the image of the spatial distribution of the virtual sound source including the strength of the virtual sound source in consideration of the spatial sensitivity characteristic in human hearing shown in FIG. 5, the strength of the virtual sound source multiplied by the spatial sensitivity coefficient for virtual sound sources present in each pixel Of the intensity of the virtual sound source is shown in light color, and the portion where the sum of the intensity of the virtual sound source is small is shown in dark color.

  As shown in FIG. 5, the spatial distribution of the virtual sound source including the strength of the virtual sound source in consideration of the spatial sensitivity characteristic in human hearing is calculated from the spatial distribution of the virtual sound source including the strength of the virtual sound source projected on the unit spherical surface. An image has been created.

  Then, the center-periphery differential processing is performed on the image showing the spatial distribution of the virtual sound source including the strength of the virtual sound source in consideration of the spatial sensitivity characteristic in human auditory sense, and a smoothing filter consisting of Gaussian functions of small variance The difference between the image to which the above is applied and the image to which the smoothing filter consisting of the Gaussian function of variance is applied is taken, and the feature map in which the feature is extracted is created.

  In the center-periphery difference processing, first, different resolution processing is performed on an image showing the spatial distribution of the virtual sound source including the strength of the virtual sound source taking into consideration the spatial sensitivity characteristics in human auditory sense, and the resolution is reduced stepwise Multiple scale images were created. For example, a plurality of scaled images with resolutions reduced to 1/2, 1/4, 1/8, etc. were created.

  In the center-periphery difference processing, next, difference processing is performed between different resolutions on a plurality of scale images showing the spatial distribution of the virtual sound source including the strength of the virtual sound source in consideration of the spatial sensitivity characteristic in human hearing. A plurality of feature maps of the spatial distribution feature of the sound field in the vehicle interior were created by extracting the difference as the spatial distribution feature of the virtual sound source including the intensity of the virtual sound source as the intensity of auditory stimulation. For example, a difference process is performed between an image indicating the spatial distribution of a virtual sound source including the strength of a virtual sound source taking into account the spatial sensitivity characteristic in human auditory sense and a scaled image whose resolution is reduced to 1/2. Each difference processing was performed to create multiple feature maps of spatial distribution features of the sound field in the vehicle compartment.

  Then, normalization processing and linear combination processing were performed on the feature map of the spatial distribution feature of the sound field in the passenger compartment, and a saliency map of the spatial distribution feature of the sound field in the passenger compartment was created.

In the normalization processing, for each feature map of the spatial distribution feature of the sound field in the vehicle compartment, the maximum value M of the stimulus strength of the feature map is calculated, and the strength of each stimulus of the feature map is from M to M The average value m of the maximum values excluding the maximum value M was calculated, and the intensity of each stimulus of the feature map was multiplied by (M−m) ² to perform normalization processing.

  In the linear combination processing, a linear sum of the feature maps normalized respectively for the feature map of the space distribution feature of the sound field in the vehicle compartment is calculated, and the vehicle interior is calculated based on the feature map of the space distribution feature of the sound field in the vehicle compartment. We created a saliency map of spatial distribution features of the sound field.

  FIG. 6 is a saliency map of spatial distribution features of the sound field in the passenger compartment. In FIG. 6, the magnitude of the intensity of the auditory stimulus is indicated by light and shade, the portion where the stimulus intensity is high is shown light, and the portion where the stimulus intensity is low is shown dark.

  As shown in FIG. 6, the saliency map of the spatial distribution feature of the sound field in the vehicle compartment is created by calculating the linear sum of the feature map normalized for each of the feature maps of the spatial distribution feature of the sound field in the vehicle compartment. did. Then, regarding the saliency map of the spatial distribution feature of the sound field in the vehicle compartment, the sum of auditory stimulation strengths is added as the saliency level (prominence value) by adding the auditory stimulation strength for each pixel Calculated. As shown in FIG. 10 described later, salience levels were calculated for the saliency map of the spatial distribution feature of the sound field in the vehicle cabin for the vehicle type A, the vehicle model B, and the vehicle model C.

Next, creation of a saliency map of frequency characteristics and time characteristics of a sound field in a vehicle compartment will be described.
When creating the saliency map of the frequency feature and time feature of the sound field in the passenger compartment, first, based on the temporal change of the sound pressure in the passenger compartment detected at the time of impulse sound generation, A spectrogram was calculated.

  FIG. 7 shows a spectrogram. In FIG. 7, the frequency is taken on the vertical axis, the time is taken on the horizontal axis, the magnitude of the intensity at each frequency is shown by color shading for each time, portions with high intensity are shown in light, and portions with low intensity are shown in dark Shown in color. As shown in FIG. 7, an image of a spectrogram was created based on the time change of the sound pressure from the generation of the impulse sound.

  The image of the spectrogram as shown in FIG. 7 was subjected to frequency feature detection filter processing for extracting a portion having a large change in intensity in the frequency direction, and an image of the spectrogram subjected to the frequency feature detection filter processing was created.

  Then, with respect to the image of the spectrogram on which the frequency feature detection filter processing has been performed, difference processing between the center and the periphery, specifically, is different as in the creation of the saliency map of the spatial distribution feature of the sound field in the vehicle compartment. Resolution processing and difference processing were performed to create multiple feature maps of frequency features of the sound field in the vehicle compartment. Next, normalization processing and linear combination processing were performed on the feature maps of the frequency features of the sound field in the plurality of vehicle compartments to create a saliency map of the frequency features of the sound field in the vehicle compartment.

  FIG. 8 is a saliency map of frequency characteristics of a sound field in a vehicle compartment. In FIG. 8, the magnitude of the intensity of the auditory stimulus is shown by shades of color, the portion with the greater stimulus intensity is shown with light, and the portion with the lesser stimulus intensity is shown with dark.

  As shown in FIG. 8, for the feature map of the frequency feature of the sound field in the vehicle compartment, the linear sum of the normalized feature map was calculated to create the saliency map of the frequency feature of the sound field in the vehicle compartment. And about the saliency map of the frequency feature of the sound field in a vehicle interior, the intensity | strength of the auditory stimulation for every pixel was added, and the sum total of the intensity | strength of auditory stimulation was computed as a saliency level. As shown in FIG. 10 described later, salience levels were calculated for the saliency map of the frequency characteristics of the sound field in the passenger compartment for the car type A, the car type B, and the car type C.

  The image of the spectrogram as shown in FIG. 7 was subjected to time feature detection filter processing for extracting a portion with a large change in intensity in the time direction, and an image of the spectrogram subjected to the time feature detection filter processing was created.

  Then, with respect to the image of the spectrogram subjected to the time feature detection filter processing, difference processing between the center and the periphery, specifically, is different as in the creation of the saliency map of the spatial distribution feature of the sound field in the vehicle compartment. A resolution process and a difference process were performed to create multiple feature maps of the time feature of the sound field in the vehicle compartment. Next, normalization processing and linear combination processing were performed on the feature maps of the time features of the sound fields in the plurality of vehicle compartments, and a saliency map of the time features of the sound fields in the vehicle compartment was created.

  FIG. 9 is a saliency map of the time characteristics of the sound field in the passenger compartment. In FIG. 9, the magnitude of the intensity of the auditory stimulus is shown by shades of color, the portion where the stimulus intensity is high is shown light, and the portion where the stimulus intensity is low is shown dark.

  As shown in FIG. 9, the saliency map of the time feature of the sound field in the passenger compartment was created by calculating the linear sum of the feature maps normalized respectively for the feature map of the time feature of the sound field in the passenger compartment. And about the saliency map of the time feature of the sound field in a vehicle interior, the intensity | strength of the auditory stimulation for every pixel was added, and the sum total of the intensity | strength of auditory stimulation was computed as a saliency level. As shown in FIG. 15 to be described later, the salience level was calculated for the saliency map of the time feature of the sound field in the vehicle cabin for the vehicle type A, the vehicle model B, and the vehicle model C.

  FIG. 10 is a graph showing saliency levels of spatial distribution features, frequency features and time features of a sound field in a vehicle cabin. As shown in FIG. 10, for vehicle type A, vehicle type B, and vehicle type C, saliency levels were calculated for the spatial distribution feature of the sound field in the vehicle interior, the frequency feature, and the saliency map of the time feature.

  FIG. 11 is a graph showing the sum of saliency levels of spatial distribution features, frequency features and time features of a sound field in a vehicle compartment. Linear combination processing is performed to calculate the linear sum of the saliency levels calculated for the spatial distribution feature of the sound field in the vehicle compartment, the frequency feature and the saliency map for the time feature, and as shown in FIG. The sum of saliency levels of spatial distribution features, frequency features and temporal features of the field was calculated.

  As a result, the sum of the spatial distribution feature of the sound field in the vehicle compartment, the frequency feature, and the saliency level of the time feature calculated in this manner becomes lower in the order of vehicle type A, vehicle type B, and vehicle type C.

  From these results, the sum of the spatial distribution feature of the sound field in the vehicle compartment, the frequency feature and the saliency level of the time feature has a correlation with the sensory evaluation for the quietness of the vehicle compartment, and It was found that the lower the sum of the spatial distribution feature, the frequency feature and the saliency level of the time feature, the more quiet the cabin.

  Further, as shown in FIG. 10, while the frequency characteristics of the sound field in the passenger compartment and the saliency levels of the time characteristics are almost equal in car type A, car type B and car type C, spatial distribution feature of sound field in passenger compartment The salience level of the car is significantly lower in the order of car type A, car type B and car type C, so the sensory evaluation for quietness of the car room and the salency level of the spatial distribution feature of the sound field in the car room are high. It was found that there is correlation, and the lower the salience level of the spatial distribution feature of the sound field in the vehicle compartment, that is, the higher the uniformity of the spatial distribution of the sound field in the vehicle cabin, the higher the quietness of the vehicle compartment.

  Therefore, based on the spatial distribution feature of the sound field in the passenger compartment, specifically the spatial distribution feature of the virtual sound source including the strength of the virtual sound source, the sound field in the passenger compartment should be properly evaluated for silence in the passenger compartment. It is considered possible. Further, regarding the quietness of the passenger compartment, it is considered that the quietness of the passenger compartment can be improved by controlling the sound field in the passenger compartment based on the evaluation result of the sound field in the passenger compartment.

Next, a vehicle interior sound field evaluation apparatus according to an embodiment of the present invention will be described.
FIG. 12 is a block diagram showing a configuration of a vehicle interior sound field evaluation device according to an embodiment of the present invention. The vehicle interior sound field evaluation device 1 according to the embodiment of the present invention evaluates a sound field in a vehicle interior of a vehicle, and as shown in FIG. 12, a sound detection unit as a sound detection unit for detecting a sound in the vehicle interior A sensor 2 and a control unit 10 that performs processing control on evaluation of a sound field in the vehicle compartment based on the sound in the vehicle compartment detected by the sound detection sensor 2 are provided.

  A microphone or the like is used as the sound detection sensor 2, and the sound detection sensor 2 is installed in a headrest or the like of a front passenger seat on which an occupant sits. The sound detection sensor 2 is configured to detect the sound pressure of the sound in the vehicle compartment and to detect the particle velocity of the sound in the vehicle compartment in the longitudinal direction of the vehicle body, the lateral direction of the vehicle, and the vertical direction of the vehicle body.

  In the control unit 10, detection data of the sound in the vehicle compartment detected by the sound detection sensor 2 is input, and based on the sound in the vehicle compartment, the sound field in the vehicle compartment is evaluated for the quietness of the vehicle compartment. ing. The control unit 10 is configured with a computer as a main part.

  The control unit 10 extracts a space distribution feature of the virtual sound source including the strength of the virtual sound source based on the sound in the vehicle compartment, and extracts a space distribution feature of the sound field in the vehicle compartment; A frequency feature extraction unit 12 that extracts frequency features of a sound field in a vehicle compartment based on sound in the room, a time feature extraction unit 13 that extracts a time feature of a sound field in a vehicle compartment based on sounds in the vehicle compartment, About the silence of the vehicle compartment based on the spatial distribution feature extracted by the distribution feature extracting unit 11, the frequency feature extracted by the frequency feature extracting unit 12, and the time feature extracted by the time feature extracting unit 13 And a sound field evaluation unit 14 for evaluating a place.

  Specifically, the space distribution feature extraction unit 11 extracts the space distribution feature of the virtual sound source including the strength of the virtual sound source based on the space sensitivity characteristic of the sound in the vehicle compartment and the human hearing, and the sound field in the vehicle compartment The feature map of the spatial distribution feature is created, and the frequency feature extraction unit 12 extracts the frequency feature of the sound field in the vehicle compartment based on the sound in the vehicle compartment and creates the feature map of the frequency feature of the sound field in the vehicle compartment The time feature extraction unit 13 extracts the time feature of the sound field in the vehicle compartment based on the sound in the vehicle compartment, and creates the feature map of the time feature of the sound field in the vehicle compartment.

  The sound field evaluation unit 14 creates the saliency map of the spatial distribution feature based on the feature map of the spatial distribution feature, creates the saliency map of the frequency feature based on the feature map of the frequency feature, and the feature map of the temporal feature Based on the saliency map of the time feature, the sound field of the vehicle interior is evaluated for the quietness of the cabin based on the spatial distribution feature, the frequency feature and the saliency map of each time feature.

  The control unit 10 is also connected to a display device 3 such as a display. The control unit 10 includes a display control unit 15 that controls the display device 3. The display control unit 15 performs display control on the display device 3 such as an image of a spatial distribution of a virtual sound source including the strength of the virtual sound source.

  FIG. 13 is a flowchart showing evaluation processing control of the vehicle interior sound field evaluation device. The evaluation processing control of the sound field in the passenger compartment is executed by the control unit 10. As shown in FIG. 13, the control unit 10 controls each time during a predetermined period, for example, 1/00 every predetermined period such as 5 ms. Detection data of the sound in the vehicle compartment detected at a position near the occupant's ear by the sound detection sensor 2 every 65000 seconds is acquired (step S1), the sound pressure of the sound in the vehicle compartment and the longitudinal direction of the vehicle body, the vehicle width direction And detection data of particle velocity in the vertical direction of the vehicle body is acquired.

  Then, based on the sound pressure and particle velocity of the sound in the vehicle compartment acquired in step S1, similar to the creation of the saliency map of the space distribution feature, the frequency feature and the time feature of the sound field in the vehicle compartment described above The process of extracting the spatial distribution feature of the sound field in the vehicle compartment (step S2), the process of extracting the frequency feature of the sound field in the vehicle compartment (step S3), and the process of extracting the time feature of the sound field in the vehicle compartment (step S4) are parallel To be done.

  FIG. 14 is a flowchart showing extraction processing of spatial distribution features. As shown in FIG. 14, in the extraction processing of the spatial distribution feature, as in the creation of the saliency map of the spatial distribution feature of the sound field in the vehicle compartment described above, the virtual sound source An image showing the spatial distribution of the virtual sound source including the strength is created (step S11).

  The strength of the virtual sound source and the position of the virtual sound source at each time are calculated based on the sound pressure of the sound in the vehicle compartment acquired in step S1 and the particle velocity in each direction, and the strength of the virtual sound source is calculated in the orthogonal coordinate system. The spatial distribution of the virtual sound source to be included is calculated. Then, the spatial distribution of the virtual sound source including the strength of the virtual sound source in the orthogonal coordinate system is projected onto the unit spherical surface, and after the spatial distribution of the virtual sound source including the strength of the virtual sound source is calculated for the unit spherical surface, Coordinate transformed to polar coordinate system.

  After that, the spatial sensitivity factor of human hearing is multiplied by the strength of each virtual sound source, and the spatial distribution of the virtual sound source including the strength of the virtual sound source is calculated in consideration of the spatial sensitivity characteristics of human hearing. An image is generated that indicates the spatial distribution of the virtual sound source, including the strength of the virtual sound source taking into account the spatial sensitivity characteristics in the auditory sense.

  In the present embodiment, the spatial sensitivity characteristic of human hearing is set to 1 directly in front of human beings, 0.5 in human's back facings, and functionally based on the cosine function from human's front to true back However, the invention is not limited thereto, for example, it is set to 1 in front of a human, 0.5 in a true rear of a human, and is linear from a direct on human to a true rear It is also possible to set so as to decrease rapidly.

  When an image showing the spatial distribution of the virtual sound source including the strength of the virtual sound source in consideration of the spatial sensitivity characteristic of human hearing in step S11 is created, the virtual sound source including the strength of the virtual sound source created in step S11 is generated. A center-peripheral difference process is performed on the image of the spatial distribution to create a plurality of feature maps of spatial distribution features of the sound field in the vehicle compartment (step S12).

  In the center-periphery difference processing in step S12, different resolution processing is performed on the image of the spatial distribution of the virtual sound source including the strength of the virtual sound source created in step S11, and a plurality of scale images are generated. A plurality of feature maps of the space distribution feature of the sound field in the vehicle compartment, in which difference processing is performed between the different resolutions and the difference is extracted as the space distribution feature of the virtual sound source including the strength of the virtual sound source It is created.

  FIG. 15 is a flowchart showing the extraction process of the frequency feature. As shown in FIG. 15, in the frequency feature extraction processing, based on the sound pressure of the sound in the vehicle compartment acquired in step S1, as in the creation of the saliency map of the frequency characteristic of the sound field in the vehicle compartment described above. Then, an image of a spectrogram which is a frequency time axis intensity distribution is created (step S21).

  Next, frequency feature detection filter processing is performed on the image of the spectrogram created in step S21 (step S22), and an image of the spectrogram on which the frequency feature detection filter processing has been performed is created (step S23).

  The center-periphery differential process is performed on the spectrogram image subjected to the frequency feature detection filter process created in step S23, and a plurality of feature maps of frequency features of the sound field in the vehicle compartment are created. (Step S24).

  FIG. 16 is a flowchart showing the extraction processing of the time feature. As shown in FIG. 16, in the time feature extraction processing, based on the sound pressure of the sound in the vehicle compartment acquired in step S1, as in the creation of the saliency map of the time feature of the sound field in the vehicle compartment described above. Then, an image of a spectrogram which is a frequency time axis intensity distribution is created (step S31). During the frequency feature extraction process, an image similar to the spectrogram created in step S21 is created. The image of the spectrogram created in step S21 may be used at the time of the extraction process of the frequency feature.

  Next, temporal feature detection filter processing is performed on the image of the spectrogram created in step S31 (step S32), and an image of the spectrogram on which the temporal feature detection filter processing has been performed is created (step S33).

  The center-periphery differential process is performed on the spectrogram image subjected to the time feature detection filter process created in step S33, and a plurality of feature maps of the time feature of the sound field in the vehicle compartment are created. (Step S34).

  When the spatial distribution feature, the frequency feature and the time feature of the sound field in the vehicle compartment are extracted in steps S2, S3 and S4, as shown in FIG. An evaluation process is performed (step S5).

  FIG. 17 is a flowchart showing evaluation processing of the sound field in the vehicle compartment. As shown in FIG. 17, in the evaluation process of the sound field in the vehicle compartment, as in the case of the creation of the saliency map of the space distribution feature, the frequency feature and the time feature of the sound field in the vehicle compartment described above, Normalization processing and linear combination processing are performed on the feature map of the spatial distribution feature, the feature map of the frequency feature created in step S24, and the feature map of the time feature created in step S34, and the sound field in the vehicle compartment The saliency map of the space distribution feature is created (step S41), the saliency map of the frequency feature of the sound field in the passenger compartment is created (step S42), and the saliency map of the sound feature in the passenger compartment is created (Step S43). In the normalization process and the linear combination process, the linear combination process may be performed after the normalization process, or the normalization process may be performed after the linear combination process.

  Then, the saliency level of the spatial distribution feature is calculated from the saliency map of the spatial distribution feature of the sound field in the vehicle compartment (step S44), and the saliency level of the frequency feature from the saliency map of the sound feature in the vehicle interior Is calculated (step S45), the saliency level of the time feature is calculated from the saliency map of the time feature of the sound field in the vehicle compartment (step S46), the spatial distribution feature, frequency feature and time feature of the sound field in the vehicle compartment The linear combination process is performed on the salency level of S. The spatial distribution feature of the sound field in the vehicle interior, the frequency feature, and the total saliency level of the time feature are calculated (step S47).

  When the space distribution feature of the sound field in the vehicle compartment, the frequency feature and the total saliency level of the time feature are calculated in step S47, the space distribution feature of the sound field in the vehicle compartment, the total salience level of the frequency feature and the time feature is calculated. It is determined whether it is equal to or less than a predetermined value set in advance (step S48). In the control unit 10, as the predetermined value, an upper limit value of all saliency levels determined to be high in quietness of the passenger compartment and good in the sound field in the passenger compartment is set and stored in advance.

  If the determination result in step S48 is YES, that is, if all salency levels are equal to or less than a predetermined value, the quietness of the vehicle compartment is high and it is evaluated that the sound field in the vehicle compartment is good (step S49). If the determination result in S48 is NO, that is, if the total saliency level is greater than the predetermined value, the quietness of the cabin is low and it is evaluated that the sound field in the cabin is not good (step S52). The sound field in the cabin is evaluated for sex. With regard to the quietness of the passenger compartment, the evaluation result of the sound field in the passenger compartment may be displayed on the display device 3.

  In this embodiment, the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on the spatial sensitivity characteristics of the sound in the vehicle compartment and the human auditory sense to extract the spatial distribution feature of the sound field in the vehicle compartment However, the spatial distribution feature of the sound field in the passenger compartment is extracted by extracting the spatial distribution feature of the virtual sound source including the strength of the virtual sound source based on the sound in the passenger compartment without considering the spatial sensitivity characteristic in human hearing. It is also possible to extract.

  In addition, although the sound field in the passenger compartment is evaluated for the quietness of the passenger compartment based on the spatial distribution feature, the frequency characteristic and the time feature of the sound field in the passenger compartment, the frequency feature and the time characteristic of the sound field in the passenger compartment It is also possible to evaluate the sound field in the passenger compartment for the quietness of the passenger compartment on the basis of the spatial distribution feature of the sound field in the passenger compartment without consideration. Also in this case, it is determined whether the saliency level of the spatial distribution feature of the sound field in the vehicle compartment is less than or equal to a predetermined value set in advance. However, the spatial distribution feature of the sound field in the vehicle compartment as the predetermined value The upper limit value of the salience level at which the quietness of the passenger compartment is high and the sound field in the passenger compartment is determined to be good is preset.

  As described above, in this embodiment, the sound in the vehicle compartment is detected, and the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on the sound in the vehicle compartment and the space distribution feature of the sound field in the vehicle compartment Are evaluated, and the sound field in the passenger compartment is evaluated for the quietness of the passenger compartment based on the spatial distribution feature of the sound field in the passenger compartment.

  Thereby, a virtual sound source including the strength of a virtual sound source, specifically, the spatial distribution feature of the sound field in the passenger compartment having correlation with the sensory evaluation of the quietness of the passenger compartment by human sense based on human auditory characteristics Since the sound field in the vehicle compartment is evaluated for the quietness of the vehicle compartment based on the spatial distribution feature of the above, it is possible to accurately evaluate the quietness of the vehicle compartment. Assess the quietness of the cabin is higher as the uniformity of the spatial distribution of the virtual sound source including the strength of the virtual sound source is higher, so that the quietness of the cabin can be accurately evaluated in consideration of the human auditory characteristics. Can.

  Also, based on the sound in the vehicle compartment, the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted to create the feature map of the spatial distribution feature of the sound field in the vehicle compartment, and the saliency map based on the feature map By evaluating the sound field in the passenger compartment with respect to the quietness of the passenger compartment based on the saliency map, it is possible to quantitatively evaluate the quietness of the passenger compartment using the saliency map.

  Also, by extracting the spatial distribution feature of the virtual sound source including the strength of the virtual sound source based on the spatial sensitivity characteristics in the car interior and the human auditory sense, the human body is extracted by extracting the spatial distribution characteristic of the sound field in the car interior It is possible to more accurately evaluate the quietness of the passenger compartment in consideration of the spatial sensitivity in the auditory sense of hearing.

  In addition, frequency characteristics and time features of the sound field in the vehicle compartment are extracted based on the sound in the vehicle compartment, and spatial distribution features of the sound field in the vehicle compartment, frequency characteristics, and quietness of the vehicle compartment based on time features. By evaluating the sound field in the room, it is possible to evaluate the sound field in the passenger compartment with respect to the quietness of the passenger compartment in consideration of frequency characteristics and time characteristics in addition to the spatial distribution feature of the sound field in the passenger compartment.

  In the embodiment described above, for the vehicle as a moving body, the sound in the vehicle compartment is detected, and the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on the sound in the vehicle compartment The spatial distribution feature of the above is extracted, and the sound field in the vehicle compartment is evaluated on the quietness of the vehicle compartment based on the spatial distribution feature, but the invention can be similarly applied to the room in other moving objects.

  In the room sound field evaluation apparatus for evaluating the sound field in the room of the moving object, a sound detection unit that detects the sound in the room of the moving object and the virtual sound source are detected based on the sound in the room of the moving object detected by the sound detection unit. A spatial distribution feature extraction unit that extracts spatial distribution features of a virtual sound source including strength and extracts spatial distribution features of the sound field in the room of the moving body, and sound in the room of the moving body extracted by the spatial distribution feature extraction unit A sound field evaluation unit is provided which evaluates the sound field in the room of the moving body for the quietness of the room of the moving body based on the spatial distribution feature of the field.

  In such a room sound field evaluation apparatus, as in the case of the car interior sound field evaluation apparatus 1, the inside of the room of the moving body having correlation with the sensory evaluation for the quietness of the room of the moving body by human sense based on human auditory characteristics Since the sound field in the room of the moving object is evaluated for the quietness of the room of the moving object based on the spatial distribution feature of the sound field, specifically the spatial distribution feature of the virtual sound source including the strength of the virtual sound source, It is possible to accurately evaluate the quietness of the room. It is evaluated that the quietness of the room of the moving body is higher as the uniformity of the spatial distribution of the virtual sound source including the strength of the virtual sound source is higher, and the accuracy of the quietness of the room of the moving body is taken into consideration It can be evaluated well.

Next, a vehicle interior sound field control apparatus according to an embodiment of the present invention will be described.
FIG. 18 is a block diagram showing a configuration of the vehicle interior sound field control device according to the embodiment of the present invention. The vehicle interior sound field control device 21 according to the embodiment of the present invention is the same as the vehicle interior sound field evaluation device 1 described above in that the sound field in the vehicle interior is evaluated based on the evaluation result of the sound field in the vehicle interior. , And the description of the same configuration as that of the vehicle interior sound field evaluation device 1 will be omitted.

  As shown in FIG. 18, the vehicle interior sound field control device 21 includes the sound detection sensor 2, the control unit 10 and the display device 3 as well as the vehicle interior sound field evaluation device 1, and a sound output device that outputs sound. It has four. A speaker or the like is used as the sound output device 4, and the sound output device 4 is disposed at a door or the like and configured to output control sound or the like for controlling a sound field in the vehicle interior.

  Similar to the control unit 10, the control unit 30 of the vehicle interior sound field control device 21 includes the spatial distribution feature extraction unit 11, the frequency feature extraction unit 12, the time feature extraction unit 13, the sound field evaluation unit 14, and the display control unit 15. While being provided, the sound field control part 36 which controls the sound field in a vehicle interior based on the evaluation result of the sound field in a vehicle interior about the quietness of a vehicle interior is provided.

  The sound field control unit 36 has low quietness in the passenger compartment and poor sound field in the passenger compartment based on the evaluation result of the sound field in the passenger compartment about the quietness of the passenger compartment evaluated by the sound field evaluation unit 14 When it is evaluated that the sound output device 4 is controlled so as to output a control sound that cancels the sound in the vehicle compartment detected by the sound detection sensor 2, the sound field in the vehicle compartment is controlled.

  For example, the sound field control unit 36 is evaluated that the quietness of the vehicle compartment is low and the sound field in the vehicle compartment is not good based on the evaluation result of the sound field on the quietness of the vehicle cabin evaluated for each predetermined period. In this case, as a control sound for canceling the sound in the vehicle compartment, the waveform of the sound pressure of the sound in the vehicle compartment detected by the sound detection sensor 2 and the waveform of the sound pressure having a predetermined phase difference, preferably an opposite phase difference The sound output device 4 is controlled to output a control sound to control the sound field in the vehicle compartment.

  FIG. 19 is a flowchart showing sound field processing control of the vehicle interior sound field control device. As shown in FIG. 19, the sound field processing control in the passenger compartment is executed by the control unit 30 in the same manner as the evaluation processing control for sound field in the passenger compartment in the passenger compartment sound field evaluation device 1. For each predetermined period, detection data of the sound in the vehicle compartment detected by the sound detection sensor 2 at each time during the predetermined period is acquired (step S1), the sound pressure of the sound in the vehicle compartment and the longitudinal direction of the vehicle body, the vehicle width direction And detection data of particle velocity in the vertical direction of the vehicle body is acquired.

  And extraction processing of space distribution feature of sound field in the vehicle compartment (step S2), extraction processing of frequency feature of sound field in the vehicle compartment (step S3), extraction processing of time feature of sound field in the vehicle compartment (step S4) Is performed in parallel, and the evaluation of the sound field in the passenger compartment is performed for the quietness of the passenger compartment (step S5).

  In the evaluation process of the sound field in the vehicle compartment, the spatial distribution feature, the frequency feature, and the saliency map of each time feature of the sound field in the vehicle compartment are created (steps S41, S42, and S43). Salience level of each feature, frequency feature and time feature is calculated (steps S44, S45, S46), space distribution feature of sound field in the vehicle compartment, total saliency level of frequency feature and time feature is calculated (step S47).

  Then, it is determined whether the spatial distribution feature of the sound field in the vehicle compartment, the frequency feature and the total saliency level of the temporal feature is less than or equal to a predetermined value set in advance (step S48), and the total saliency level is a predetermined value. In the following cases, the quietness of the cabin is high and it is evaluated that the sound field in the cabin is good (step S49), and the quietness of the cabin is low when the total saliency level is larger than a predetermined value It is evaluated that the sound field in the room is not good (step S50).

  When the sound field in the vehicle compartment is evaluated for quietness in the vehicle compartment in step S5, sound field control processing in the vehicle compartment is performed based on the evaluation result of the sound field in the vehicle compartment for silence in the vehicle compartment ( Step S56). In the sound field control processing in the passenger compartment, when the quietness of the passenger compartment is low in step S50 and the sound field in the passenger compartment is evaluated as not good, it is acquired in step S1 as a control sound for canceling the sound in the passenger compartment. Based on the sound pressure of the sound in the passenger compartment, control of the sound pressure of the sound in the passenger compartment detected by the sound detection sensor 2 and the waveform of the sound pressure having a predetermined phase difference, preferably a phase difference of opposite phase The sound output device 4 is controlled to output a sound to control the sound field in the vehicle interior.

  In the sound field control process in the passenger compartment, when it is evaluated that the quietness of the passenger compartment is high and the sound field in the passenger compartment is good in step S49, the control sound for canceling the sound in the passenger compartment is not output. The output device 4 is controlled.

  Also in the passenger compartment sound field control device 21 according to the present embodiment, the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on the sound in the passenger compartment and the spatial sensitivity characteristic in human hearing. Although the spatial distribution feature of the sound field is extracted, the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on the sound in the vehicle compartment without considering the spatial sensitivity characteristic in human hearing It is also possible to extract spatial distribution features of the sound field in the passenger compartment.

  In addition, although the sound field in the passenger compartment is evaluated for the quietness of the passenger compartment based on the spatial distribution feature, the frequency feature, and the time feature of the sound field in the passenger compartment, the frequency feature and time characteristic of the sound field in the passenger compartment It is also possible to evaluate the sound field in the passenger compartment based on the spatial distribution feature of the sound field in the passenger compartment without considering the Also in this case, it is determined whether the saliency level of the spatial distribution feature of the sound field in the vehicle compartment is less than or equal to a predetermined value set in advance. However, the spatial distribution feature of the sound field in the vehicle compartment as the predetermined value The upper limit value of the salience level at which the quietness of the passenger compartment is high and the sound field in the passenger compartment is determined to be good is preset.

  As described above, in the in-room sound field control device 21 according to the present embodiment, the sound in the vehicle compartment is detected, and the spatial distribution feature of the virtual sound source including the strength of the virtual sound source is extracted based on the sound in the vehicle interior. The spatial distribution feature of the sound field in the vehicle compartment is extracted, the sound field in the vehicle compartment is evaluated for the quietness of the vehicle compartment on the basis of the spatial distribution feature of the sound field in the vehicle compartment, The sound field in the passenger compartment is controlled based on the evaluation result of the sound field.

  Thereby, a virtual sound source including the strength of a virtual sound source, specifically, the spatial distribution feature of the sound field in the passenger compartment having correlation with the sensory evaluation of the quietness of the passenger compartment by human sense based on human auditory characteristics Since the sound field in the vehicle compartment is evaluated for the quietness of the vehicle compartment based on the spatial distribution feature of the above, it is possible to accurately evaluate the quietness of the vehicle compartment. And since the sound field in a vehicle interior is controlled based on the evaluation result of the sound field in the vehicle interior about the quietness of the vehicle interior evaluated with sufficient accuracy, the quietness of a vehicle interior can be improved effectively. By controlling the sound field in the vehicle compartment so as to cancel the sound in the vehicle compartment based on the evaluation result of the sound field in the vehicle compartment about the quietness of the vehicle compartment, the quietness of the vehicle compartment can be effectively improved. .

  In the embodiment described above, a salency map is created for three features in the sound field in the vehicle compartment, specifically, spatial distribution features, frequency features and time features, and the sound field in the vehicle compartment is evaluated for the quietness of the vehicle compartment. However, it is also possible to create a Salency map for other characteristics in addition to spatial distribution features, frequency features and time features in the sound field in the passenger compartment to evaluate the sound field in the passenger compartment for quietness of the passenger compartment. It is possible.

  The present invention is not limited to the illustrated embodiment, and various improvements and design changes are possible without departing from the scope of the present invention.

  As described above, according to the present invention, it is possible to evaluate the quietness of the compartment with high accuracy, for example, at the time of manufacture of a vehicle, at the time of traveling of a vehicle, etc. There is a possibility.

1 Car interior sound field evaluation device 2 Sound detection sensor 3 Display device 4 Sound output device 10, 30 Control unit 11 Space distribution feature extraction unit 12 Frequency feature extraction unit 13 Time feature extraction unit 14 Sound field evaluation unit 15 Display control unit 21 Car Room sound field controller 36 sound field controller

Claims (7)

A vehicle interior sound field evaluation device for evaluating a sound field in a vehicle interior,
A sound detection unit that detects a sound in the vehicle compartment;
A spatial distribution feature extraction unit for extracting spatial distribution features of a sound field in a vehicle interior by extracting spatial distribution features of a virtual sound source including the strength of a virtual sound source based on the sound in the vehicle compartment detected by the sound detection unit; ,
A sound field evaluation unit that evaluates a sound field in a vehicle compartment about silence in the vehicle compartment based on the space distribution feature of a sound field in the vehicle compartment extracted by the space distribution feature extraction unit;
A vehicle interior sound field evaluation device characterized by having. The spatial distribution feature extraction unit extracts spatial distribution features of the virtual sound source including the strength of the virtual sound source based on the sound in the vehicle compartment detected by the sound detection unit, and generates spatial distribution features of the sound field in the vehicle compartment. Create a feature map,
The sound field evaluation unit generates a saliency map of a space distribution feature of a sound field in a vehicle interior based on the feature map of the space distribution feature created by the space distribution feature extraction unit, and the salient feature of the space distribution feature Assess the sound field in the cabin about the quietness of the cabin based on the safety map,
The vehicle interior sound field evaluation device according to claim 1 characterized by things. The space distribution feature extraction unit extracts a space distribution feature of a virtual sound source including the strength of a virtual sound source based on the sound in the vehicle compartment detected by the sound detection unit and the space sensitivity characteristic of human hearing. Extract spatial distribution features of the sound field of
The vehicle interior sound field evaluation device according to claim 1 characterized by things. A frequency feature extraction unit for extracting frequency features of a sound field in the vehicle compartment based on the sound in the vehicle compartment detected by the sound detection unit;
A time feature extraction unit that extracts a time feature of a sound field in the vehicle compartment based on the sound in the vehicle compartment detected by the sound detection unit;
Equipped with
The sound field evaluation unit is a space distribution feature of a sound field in a vehicle compartment extracted by the space distribution feature extraction unit, a frequency feature of a sound field in a vehicle compartment extracted by the frequency feature extraction unit, and the time feature extraction Evaluating the sound field in the passenger compartment for the quietness of the passenger compartment based on the time characteristics of the sound field in the passenger compartment extracted by the department
The vehicle interior sound field evaluation apparatus according to any one of claims 1 to 3, characterized in that: A vehicle interior sound field evaluation method for evaluating a sound field in a vehicle interior,
A sound detection step of detecting a sound in the vehicle compartment;
A spatial distribution feature extracting step of extracting a spatial distribution feature of a sound field in a vehicle compartment by extracting a spatial distribution feature of a virtual sound source including the strength of a virtual sound source based on the sound in the vehicle compartment detected by the sound detecting step; ,
A sound field evaluation step of evaluating a sound field in the vehicle compartment about silence in the vehicle compartment based on the space distribution feature of the sound field in the vehicle compartment extracted by the space distribution feature extraction step;
The vehicle interior sound field evaluation method characterized by having. A vehicle interior sound field control apparatus for controlling a sound field in a vehicle interior, comprising:
A sound detection unit that detects a sound in the vehicle compartment;
A spatial distribution feature extraction unit for extracting spatial distribution features of a sound field in a vehicle interior by extracting spatial distribution features of a virtual sound source including the strength of a virtual sound source based on the sound in the vehicle compartment detected by the sound detection unit; ,
A sound field evaluation unit that evaluates a sound field in a vehicle compartment about silence in the vehicle compartment based on the space distribution feature of a sound field in the vehicle compartment extracted by the space distribution feature extraction unit;
A sound field control unit that controls a sound field in the vehicle compartment based on an evaluation result of a sound field in the vehicle compartment about the quietness of the vehicle compartment evaluated by the sound field evaluation unit;
An indoor sound field control device characterized by comprising. A room sound field evaluation device for evaluating a room's sound field of a moving body,
A sound detection unit that detects the sound in the room of the moving object;
Spatial distribution feature for extracting the spatial distribution feature of the virtual sound source including the strength of the virtual sound source based on the sound in the room of the moving body detected by the sound detection unit to extract the spatial distribution feature of the sound field in the room of the moving body A feature extraction unit,
A sound field evaluation unit which evaluates the sound field in the room of the moving body with respect to the quietness of the room of the moving body based on the space distribution feature of the sound field in the room of the moving body extracted by the space distribution feature extraction unit;
A room sound field evaluation device characterized by comprising.