Sound source direction detection system, speaker set and sound source direction detection device

Abstract

To provide a sound source direction detection system, a speaker set and a sound source direction detection device that can precisely detect the direction of a sound source inside or outside a vehicle without requiring any troublesome setting operation.SOLUTION: A sound source direction detection system has: a speaker group including at least one speaker attachable to a speaker fixation part in the cabin of a vehicle; a plurality of microphones installed at the speaker group; a microphone installation position acquisition part which specifies installation positions of the respective microphones based upon the installation position of the speaker fixation part, and obtains microphone installation position information representing the installation positions of the respective microphones; and a direction detection part which detects the direction of a sound source based upon microphone sound reception signals obtained by receiving a sound by the plurality of microphones, and the installation positions of the microphones represented with the microphone installation position information.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sound source direction detection system for detecting the direction of a sound source generated inside or outside a moving body, particularly a vehicle, and to a speaker set and sound source direction detection device included in the sound source direction detection system. [Background technology]

[0002] In recent years, a sound source detection system has been proposed for use in vehicle driving assistance, etc., that detects the direction of a sound source from within the vehicle itself, such as a siren from an emergency vehicle or a horn from another vehicle (see, for example, Patent Document 1). In this sound source detection system, multiple microphones (hereinafter referred to as "mics") are installed on the exterior surface of the vehicle, and the direction of the sound source is detected based on multiple sound signals obtained by collecting sounds with the multiple microphones. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-67381 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned sound source detection system, the accuracy of detecting the direction of the sound source increases when the distance between the microphones is increased, but in this case, the installation position (3D coordinates) of each microphone must be taken into consideration in order to correctly detect the direction of the sound source. Therefore, the installation position of each microphone must be set in advance on the system side.

[0005] However, in order to perform such settings, the user or the installer must measure the installation position of each microphone and input the measurement results into the system, which is a cumbersome task.

[0006] Therefore, an object of the present invention is to provide a sound source direction detection system, a speaker set, and a sound source direction detection device that can accurately detect the direction of a sound source inside or outside a vehicle without requiring cumbersome setting work. [Means for solving the problem]

[0007] The invention described in claim 1 is a sound source direction detection system that detects the direction of a sound source inside or outside a vehicle, characterized in that it comprises: a speaker group including at least one speaker that can be attached to a speaker fixing part inside the vehicle; a plurality of microphones installed in the speaker group; a microphone installation position acquisition part that identifies the installation position of each of the microphones based on the installation position of the speaker fixing part and obtains microphone installation position information indicating the installation position of each of the microphones; and a direction detection part that detects the direction of the sound source based on microphone reception signals obtained by receiving sound with each of the plurality of microphones and the installation position of each of the microphones indicated by the microphone installation position information.

[0008] The invention described in claim 9 is a sound source direction detection system that detects the direction of a sound source inside or outside a vehicle, comprising: a speaker that can be attached to a speaker fixing part inside the vehicle; at least four microphones installed on a first of the speakers; a microphone installation position acquisition part that identifies the installation position of each of the four microphones based on the position of the speaker fixing part and obtains microphone installation position information indicating the installation position of each of the microphones; and a direction detection part that detects the direction of the sound source based on each of the microphone reception signals received by the four microphones and the installation positions of each of the microphones indicated by the microphone installation position information, wherein one of the four microphones is installed in a position in an area that is not included in a plane defined by the installation points of the other three microphones.

[0009] The invention described in claim 11 is a speaker set included in a sound source direction detection system that detects the direction of a sound source inside or outside a vehicle based on microphone reception signals received by each of a plurality of microphones installed in the vehicle cabin and the installation positions of each of the plurality of microphones, characterized in that the plurality of microphones, each of whose installation positions is identified based on the position of the speaker fixing part, are installed on speakers that can be attached to speaker fixing parts installed in predetermined positions in the vehicle cabin.

[0010] The invention described in claim 12 is characterized by comprising: a connector that receives a plurality of microphone reception signals obtained by receiving sound with a plurality of microphones installed in a speaker group including at least one speaker that can be attached to a speaker fixing part inside a vehicle cabin; a microphone installation position acquisition part that identifies the installation position of each of the microphones based on the installation position of the speaker fixing part and obtains microphone installation position information indicating the installation position of each of the microphones; and a direction detection circuit that detects the direction of a sound source inside or outside the vehicle based on the plurality of microphone reception signals received by the connector and the installation positions of each of the plurality of microphones indicated by the microphone installation position information. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a block diagram showing the configuration of a sound source direction detection system 100 mounted on a vehicle. [Figure 2] 1 is a perspective view showing the installation positions of a car audio device 10, speaker sets 20a to 20d, and a sound source direction detection unit 30, as viewed from above a vehicle 200. FIG. [Figure 3] FIG. 10 is a diagram showing the positional relationship between microphones M1 to M4 installed on speakers SP of speaker sets 20a to 20d, respectively, when installed on speaker fixing portions MPa to MPd. [Figure 4] FIG. 2 is a block diagram showing an example of the internal configuration of a microphone sound superimposing unit MSP included in a speaker set 20a. [Figure 5] FIG. 2 is a block diagram showing an example of the configuration of a sound source direction detection unit 30. [Figure 6] FIG. 2 is a diagram showing an example of the contents stored in a memory 306a. [Figure 7] FIG. 10 is a diagram showing the positional relationship when one microphone M1 is installed on each speaker SP of speaker sets 20a to 20d in a state where the speakers are installed on speaker fixing portions MPa to MPd, respectively. [Figure 8] FIG. 10 is a diagram showing the positional relationship when two microphones M1 are installed on the speakers SP of each of the speaker sets 20a to 20d, with the speakers installed on the speaker fixing portions MPa to MPd, respectively. [Figure 9] 1 is a diagram showing the positional relationship of each of microphones M1 to M4 installed on a speaker SP having a frame fm whose surface is made up of a concave (or convex) area AR1 and a convex (or concave) area AR2. [Figure 10A] 10 is a diagram showing the shape of the surface of the frame fm of the speaker SP, viewed from the direction of the white arrow in the case where the area AR1 of the frame fm is convex and the area AR2 is concave. [Figure 10B] 10 is a diagram showing the shape of the surface of the frame fm of the speaker SP when the area AR1 of the frame fm is concave and the area AR2 is convex, as viewed from the direction of the white arrow in FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the present invention will now be described in detail.

[0013] FIG. 1 is a block diagram showing the configuration of a sound source direction detection system 100 mounted on a vehicle.

[0014] The sound source direction detection system 100 includes a car audio device 10, speaker sets 20a to 20d with microphones, and a sound source direction detection unit 30.

[0015] The car audio device 10 includes a playback device that plays back music signals from a CD, DVD, Blu-ray disc, hard disk, semiconductor, etc., and an FM / AM receiver (none of which are shown). The car audio device 10 also includes BTL (Bridged Transformer Less) connection amplifiers 10a to 10d that individually amplify four-channel audio signals output from the playback device or FM / AM receiver and output them via BTL.

[0016] The BTL connection amplifiers 10a to 10d individually amplify the four-channel audio signals to generate four-channel amplified audio signals as speaker driving signals, and supply these to the connectors CN1 to CN4 as BTL output audio signals, respectively.

[0017] 1, one end of each of speaker cables SC1 to SC4 is connected to connectors CN1 to CN4, and the other end of each of the speaker cables SC1 to SC4 is connected to a speaker set 20a to 20d. Each of the speaker cables SC1 to SC4 actually includes two signal lines, each consisting of at least a positive core wire and a negative core wire.

[0018] Therefore, the BTL output audio signals output from the BTL connection amplifiers 10a to 10d are supplied to the speaker sets 20a to 20d via the connectors CN1 to CN4 and the speaker cables SC1 to SC4.

[0019] Each of the speaker sets 20a to 20d has the same internal configuration, i.e., a connector CN to which a speaker cable is connected, a speaker SP, and a microphone sound superimposing unit MSP. The speaker SP of each of the speaker sets 20a to 20d has a structure that allows it to be attached to speaker fixing parts provided at four predetermined locations inside the vehicle.

[0020] FIG. 2 is a perspective view showing an example of the installation positions of the car audio device 10, speaker sets 20a to 20d, and sound source direction detection section 30, as viewed from above the vehicle 200. As shown in FIG.

[0021] As shown in Fig. 2, the car audio device 10 and the sound source direction detection unit 30 are housed in the instrument panel of the vehicle 200. According to the example shown in Fig. 2, the driver's side door FR of the front doors of the vehicle 200 is provided with a speaker fixing portion MPa to which a speaker SP of the speaker set 20a can be attached. The passenger's side door FL of the front doors of the vehicle 200 is provided with a speaker fixing portion MPb to which a speaker SP of the speaker set 20b can be attached. The rear right door RR of the rear doors of the vehicle 200 is provided with a speaker fixing portion MPc to which a speaker SP of the speaker set 20c can be attached. Furthermore, the rear left door RL of the rear doors of the vehicle 200 is provided with a speaker fixing portion MPd to which a speaker SP of the speaker set 20d can be attached. Therefore, in the interior of the vehicle 200, the speakers SP of the speaker sets 20a to 20d are attached to the speaker fixing portions MPa to MPd, respectively.

[0022] Here, the speakers SP of the speaker sets 20a to 20d attached to the speaker fixing portions MPa to MPd, respectively, output sounds based on the BTL output audio signals received via the speaker cables and the connectors CN.

[0023] The speakers SP of each of the speaker sets 20a to 20d are speakers with microphones, each equipped with four microphones M1 to M4.

[0024] FIG. 3 is a diagram showing the positional relationship of the microphones M1 to M4 installed on the speakers SP of the speaker sets 20a to 20d when they are installed on the speaker fixing portions MPa to MPd, respectively.

[0025] As shown in Figure 3, microphones M1 to M4 (indicated by ●) are installed on the surface of a frame fm that supports the edge of the vibrating body dp of the speaker SP, with each sound-receiving vibrating body exposed to the interior of the vehicle.

[0026] As shown in FIG. 3, the microphones M1 to M4 are installed on the surface of the frame fm at positions at different heights from the floor inside the vehicle cabin, with the speaker SP attached to the speaker fixing portion.

[0027] This allows at least three of the distances in the height direction from the microphones M1 to M4 to the sound source to be different, thereby improving the accuracy of detecting the direction of the sound source.

[0028] In addition, in order to improve the accuracy of detecting the direction of the sound source, it is desirable to space the microphones as far apart as possible. Therefore, in the example shown in Fig. 3, two of the microphones M1 to M4, microphones M1 and M3, are placed on diagonal lines sandwiching the vibrating body dp.

[0029] The microphones M1 to M4 supply microphone reception signals s1 to s4 obtained by receiving sounds, respectively, to a microphone sound superimposing unit MSP.

[0030] The microphone sound superimposing unit MSP serializes digital signals based on the microphone received signals s1 to s4 in the form of differential signals with frequencies higher than the audible band (for example, 20 Hz to 20 KHz) to form serial transmission signals ms, which are superimposed on the speaker cable via the connector CN. The microphone sound superimposing unit MSP is implemented, for example, in a semiconductor IC mounted on a printed circuit board installed on the magnet of the speaker SP or on a frame supporting the magnet.

[0031] FIG. 4 is a block diagram showing an example of the internal configuration of the microphone sound superimposing unit MSP included in the speaker set 20a out of the speaker sets 20a to 20d.

[0032] In the example shown in Fig. 4, the microphone sound superimposing unit MSP includes a low-pass filter 51, a constant voltage circuit 52, a microphone driver 53, AD converters 54a to 54d, a serial conversion circuit 55, a differential signal conversion circuit 56, and a high-pass filter 57. Note that the high-pass filter may hereinafter be abbreviated as HPF. Also, in Fig. 4, the speaker cable SC1 connected to the speaker set 20a includes a positive core wire L1 and a negative core wire L2.

[0033] The low-pass filter 51 extracts a DC or low-frequency voltage close to DC from the negative core wire L2 and supplies it to the constant voltage circuit 52. That is, while the BTL connection amplifier (10a) is outputting a BTL output audio signal representing silence, a predetermined DC voltage (e.g., 7 volts) is superimposed on the BTL output audio signal. Therefore, the low-pass filter 51 extracts this DC voltage from the negative core wire L2. Note that hereinafter, the low-pass filter may also be abbreviated as LPF. Furthermore, the constant voltage circuit 52 may include a rectifier circuit formed of a diode, a capacitor, etc., so that it can generate a DC voltage even while the BTL connection amplifier (10a) is outputting a low-frequency audio signal superimposed on the predetermined DC voltage.

[0034] The constant voltage circuit 52 receives the voltage supplied from the LPF 51 and generates, based on this voltage, a power supply voltage with a constant voltage value for operating the microphone driver 53, the AD converters 54a to 54d, the serial conversion circuit 55, the differential signal conversion circuit 56, and the HPF 57.

[0035] That is, the LPF 51 and the constant voltage circuit 52 function as a power supply circuit that generates a power supply voltage based on the BTL output audio signal transmitted through the speaker cable.

[0036] The microphone driver 53, the AD converters 54a to 54d, the serial conversion circuit 55, the differential signal conversion circuit 56, and the HPF 57 receive the power supply voltage supplied from the constant voltage circuit 52 and perform the following operations.

[0037] The microphone driver 53 amplifies the microphone reception signals s1 to s4 supplied from the microphones M1 to M4 individually and supplies the amplified signals to the AD converters 54a to 54d.

[0038] The AD converters 54a to 54d convert the analog microphone reception signals s1 to s4 into digital reception signals d1 to d4, respectively, and supply them to the serial conversion circuit 55.

[0039] The serial conversion circuit 55 receives a clock signal CLK having a frequency higher than the audible band, for example, 100 KHz, and generates a multiplexed serial signal sd by sequentially connecting the digital received sound signals d1 to d4 in a serial form in accordance with the clock signal CLK, and supplies the multiplexed serial signal sd to a differential signal conversion circuit 56.

[0040] The differential signal conversion circuit 56 converts the serial signal sd into a differential signal format and supplies the resulting serial transmission signals md1 and md2 to the HPF 57.

[0041] HPF57 passes frequency components higher than the audible range from each of serial transmission signals md1 and md2, supplies serial transmission signal md1 to connector CN to which positive core wire L1 of speaker cable SC1 is connected, and supplies serial transmission signal ms2 to connector CN to which negative core wire L2 of speaker cable SC1 is connected.

[0042] Therefore, with the configuration shown in FIG. 4, the microphone sound superimposing unit MSP superimposes serial transmission signals ms1 and ms2 in the form of differential signals representing the microphone received sound signals s1 to s4 onto the speaker cable SC1 via the connector CN.

[0043] The sound source direction detection unit 30 is connected to the connectors CN1 to CN4, and receives the electrical signals flowing through the speaker cables SC1 to SC4 via the connectors CN1 to CN4. The sound source direction detection unit 30 then detects the direction of the sound source of a sound generated outside or inside the vehicle 200 based on the serial transmission signal flowing through the speaker cables SC1 to SC4, and outputs a sound source direction signal SSD indicating the direction of the sound source.

[0044] FIG. 5 is a block diagram showing an example of the configuration of the sound source direction detection unit 30. As shown in FIG.

[0045] In the example shown in FIG. 5, the sound source direction detection unit 30 includes HPFs 301a to 301d, digital conversion circuits 302a to 302d, separation circuits 303a to 303d, a direction detection circuit 304, an operation unit 305, and an installation position acquisition unit 306.

[0046] The HPF 301a is connected to the core wires L1 and L2 of the speaker cable SC1, extracts signals with frequencies higher than the audible band from the electrical signals flowing through these core wires L1 and L2, and supplies each of these signals to the digital conversion circuit 302a. The core wires L1 and L2 of the speaker cable SC1 also carry the BTL output audio signal in the audible band output from the BTL-connected amplifier 10a, and the serial transmission signals ms1 and ms2 in the inaudible band output from the microphone sound superimposition unit MSP of the speaker set 20a. Therefore, the HPF 301a extracts the serial transmission signals ms1 and ms2 sent from the microphone sound superimposition unit MSP of the speaker set 20a from the core wires L1 and L2 of the speaker cable SC1, and supplies each of these signals to the digital conversion circuit 302a.

[0047] The HPF 301b is connected to the core wires L1 and L2 of the speaker cable SC2, extracts signals with frequencies higher than the audible band from the electrical signals flowing through these core wires L1 and L2, and supplies each of these signals to a digital conversion circuit 302b. The core wires L1 and L2 of the speaker cable SC2 also carry a BTL output audio signal in the audible band output from the BTL-connected amplifier 10b, and serial transmission signals ms1 and ms2 in the inaudible band output from the microphone sound superimposition unit MSP of the speaker set 20b. Therefore, the HPF 301b extracts the serial transmission signals ms1 and ms2 sent from the microphone sound superimposition unit MSP of the speaker set 20b from the core wires L1 and L2 of the speaker cable SC2, and supplies each of these signals to the digital conversion circuit 302b.

[0048] The HPF 301c is connected to the core wires L1 and L2 of the speaker cable SC3, extracts signals with frequencies higher than the audible band from the electrical signals flowing through these core wires L1 and L2, and supplies each of these signals to a digital conversion circuit 302c. The core wires L1 and L2 of the speaker cable SC3 also carry a BTL output audio signal in the audible band output from the BTL-connected amplifier 10c, and serial transmission signals ms1 and ms2 in the inaudible band output from the microphone sound superimposition unit MSP of the speaker set 20c. Therefore, the HPF 301c extracts the serial transmission signals ms1 and ms2 sent from the microphone sound superimposition unit MSP of the speaker set 20c from the core wires L1 and L2 of the speaker cable SC3, and supplies each of these signals to the digital conversion circuit 302c.

[0049] The HPF 301d is connected to the core wires L1 and L2 of the speaker cable SC4, extracts signals with frequencies higher than the audible band from the electrical signals flowing through these core wires L1 and L2, and supplies each of these signals to a digital conversion circuit 302d. The core wires L1 and L2 of the speaker cable SC4 also carry a BTL output audio signal in the audible band output from the BTL-connected amplifier 10d, and serial transmission signals ms1 and ms2 in the inaudible band output from the microphone sound superimposition unit MSP of the speaker set 20d. Therefore, the HPF 301d extracts the serial transmission signals ms1 and ms2 sent from the microphone sound superimposition unit MSP of the speaker set 20d from the core wires L1 and L2 of the speaker cable SC4, and supplies each of these signals to a digital conversion circuit 302d.

[0050] The digital conversion circuit 302a converts the signal based on the differential voltage between the serial transmission signals ms1 and ms2 supplied from the HPF 301a, restoring the serial signal sda before being converted by the differential signal conversion circuit 56. Through this conversion process, the digital conversion circuit 302a restores the serial signal sda representing the digital received sound signals d1 to d4 obtained by the microphones M1 to M4 of the speaker set 20a, and supplies the serial signal sda to the separation circuit 303a. The digital conversion circuit 302b performs the above-mentioned conversion process on the serial transmission signals ms1 and ms2 supplied from the HPF 301b, restoring the serial signal sdb representing the digital received sound signals d1 to d4 obtained by the microphones M1 to M4 of the speaker set 20b. The digital conversion circuit 302b supplies the restored serial signal sdb to the separation circuit 303b. The digital conversion circuit 302c performs the above-mentioned conversion processing on the serial transmission signals ms1 and ms2 supplied from the HPF 301c to restore a serial signal sdc representing the digital received sound signals d1 to d4 obtained by the microphones M1 to M4 of the speaker set 20c. The digital conversion circuit 302c supplies the restored serial signal sdc to the separation circuit 303c. The digital conversion circuit 302d performs the above-mentioned conversion processing on the serial transmission signals ms1 and ms2 supplied from the HPF 301d to restore a differential serial signal sdd representing the digital received sound signals d1 to d4 obtained by the microphones M1 to M4 of the speaker set 20d. The digital conversion circuit 302d supplies the restored serial signal sdd to the separation circuit 303d.

[0051] The separation circuit 303a separates and extracts the digital received signals d1 to d4 acquired by the microphones M1 to M4 of the speaker set 20a from the serial signal sda supplied from the digital conversion circuit 302a, and supplies them as microphone received signals Sa1 to Sa4 to the direction detection circuit 304. The separation circuit 303b separates and extracts the digital received signals d1 to d4 acquired by the microphones M1 to M4 of the speaker set 20b from the serial signal sdb supplied from the digital conversion circuit 302b, and supplies them as microphone received signals Sb1 to Sb4 to the direction detection circuit 304. The separation circuit 303c separates and extracts the digital received signals d1 to d4 acquired by the microphones M1 to M4 of the speaker set 20c from the serial signal sdc supplied from the digital conversion circuit 302c, and supplies them as microphone received signals Sc1 to Sc4 to the direction detection circuit 304. The separation circuit 303d separates and extracts the digital received signals d1 to d4 acquired by the microphones M1 to M4 of the speaker set 20d from the serial signal sdd supplied from the digital conversion circuit 302d, and supplies them to the direction detection circuit 304 as microphone received signals Sd1 to Sd4, respectively.

[0052] In this way, in the sound source direction detection unit 30, an extraction unit composed of HPFs 301a to 301d, digital conversion circuits 302a to 302d, and separation circuits 303a to 303d extracts 16 microphone signals obtained by receiving sound with microphones M1 to M4 of each of speaker sets 20a to 20d from the electrical signals flowing through each of connectors CN1 to CN4.

[0053] The operation unit 305 accepts an operation by the user to specify the model of the vehicle 200, and supplies the installation position acquisition unit 306 with model information indicating the model (type) of the vehicle 200.

[0054] The installation position acquisition unit 306 includes a memory 306a and a microphone position identification unit 306b.

[0055] 6, the memory 306a stores in advance information representing the installation position of each of the speaker fixing parts MPa to MPd in ​​each vehicle by three-dimensional coordinates (X, Y, Z) for each type of vehicle. Here, the installation position of each of the speaker fixing parts MPa to MPd indicates a relative position with respect to a predetermined reference position in the interior of the vehicle 200 (for example, the position of the driver's seat).

[0056] The installation position acquisition unit 306 reads from the memory 306a information indicating the installation position of each speaker fixing unit (MPa to MPd) corresponding to the vehicle model indicated by the vehicle model information supplied from the operation unit 305. The microphone position identification unit 306b identifies the installation position (three-dimensional coordinates) of each of the microphones M1 to M4 shown in FIG. 3 that are installed on the speaker SP of each of the speaker sets 20a to 20d, based on the installation position information of the speaker fixing units read from the memory 306a. The installation position acquisition unit 306 supplies the direction detection circuit 304 with microphone installation position information indicating the installation position of each of the 16 microphones, consisting of the microphones M1 to M4 included in each of the speaker sets 20a to 20d, identified by the microphone position identification unit 306b.

[0057] The direction detection circuit 304 first detects the amplitude differences and phase differences (differences in the arrival times of sounds from the sound source) between the microphone reception signals Sa1-Sa4, Sb1-Sb4, Sc1-Sc4, and Sd1-Sd4. Next, the direction detection circuit 304 identifies the direction of the sound source generated inside or outside the vehicle based on the detected amplitude differences and phase differences between the microphone reception signals and the installation positions of the 16 microphones indicated by the microphone installation position information. Note that the direction detection circuit 304 may determine whether the sound source is inside or outside the vehicle based on the microphone reception signals (Sa1-Sa4, Sb1-Sb4, Sc1-Sc4, Sd1-Sd4), and then identify the sound source direction using an algorithm optimal for identifying the inside sound source direction or an algorithm optimal for identifying the outside sound source direction according to the determination result. The direction detection circuit 304 may also determine the direction of the sound source based on the microphone reception signals and microphone installation position information, in accordance with a whitening cross-correlation (cross-power spectrum phase analysis) method.

[0058] The direction detection circuit 304 outputs a sound source direction signal SSD indicating the sound source direction identified as described above.

[0059] As described above in detail, the sound source direction detecting system 100 employs the speaker SP, which is equipped with four microphones M1 to M4, as an in-vehicle speaker.

[0060] Here, the in-vehicle speaker is provided, for example, on the interior surface of the vehicle door, and is attached to a speaker fixing portion whose installation position is predetermined for each vehicle model. Therefore, based on the position of the speaker fixing portion, the installation positions of the microphones M1 to M4 installed on the speaker SP can be known.

[0061] Therefore, in the sound source direction detection system 100, information indicating the installation position (three-dimensional coordinates) of each of the speaker fixing parts MPa to MPd is registered in advance in the memory 306a of the installation position acquisition unit 306, associated with each vehicle model as shown in Fig. 6. Here, the installation position acquisition unit 306 first reads out the installation position (three-dimensional coordinates) of each of the speaker fixing parts MPa to MPd corresponding to the vehicle model of the host vehicle (200) from the memory 306a. Then, the microphone position identification unit 306b of the installation position acquisition unit 306 identifies the installation position (three-dimensional coordinates) of each of the microphones M1 to M4 installed on the speaker SP attached thereto, from the installation position of each of the speaker fixing parts MPa to MPd. In other words, when fixed to the speaker fixing part, the relative position of each of the microphones M1 to M4 on the surface of the frame fm of each speaker SP is known. Therefore, if the installation position of the speaker fixing part is known from the registered contents of memory 306a, it is possible to identify the installation positions of the speakers installed on the speaker SP attached to that speaker fixing part.

[0062] In this way, in the sound source direction detection system 100, by integrating the microphones M1 to MP4 for detecting the sound source direction with the in-vehicle speaker SP, it is possible to obtain information indicating the installation position of each microphone without having to measure the installation position (three-dimensional coordinates) of each microphone and input the measurement results.

[0063] Therefore, by using the acquired information indicating the installation position of each microphone, the sound source direction detection unit 30 can perform highly accurate sound source direction detection based on the microphone reception signals obtained by receiving sound with multiple microphones installed at a distance from each other.

[0064] Furthermore, in the sound source direction detection system 100, microphone reception signals s1 to s4 obtained by receiving sound with microphones M1 to M4 installed in a speaker SP that generates sound corresponding to an audio signal input via a speaker cable (for example, SC1) are superimposed on the speaker cable and transmitted to the sound source direction detection unit 30. Specifically, a microphone sound superimposition unit MSP provided in the speaker SP serializes the microphone reception signals s1 to s4 in the form of differential signals with frequencies higher than the audible band, and superimposes the serial transmission signals onto the speaker cable.

[0065] This eliminates the need for dedicated wiring for transmitting the microphone pickup signals. Furthermore, by attaching the speaker SP to the speaker fixing part, the installation of multiple microphones can be completed at the same time, eliminating the need to install the dedicated cables and microphones in the vehicle 200.

[0066] Therefore, it is possible to simplify the installation work for installing the sound source direction detection system 100 in the vehicle 100, and also reduce costs by eliminating the need for dedicated wiring. In the above embodiment, the installation position of each microphone is acquired based on the installation position information of each speaker fixing unit (MPa to MPd) for each vehicle model that is pre-registered in the memory 306a. However, there is a case where the vehicle model corresponding to the actual vehicle 200 is not registered in the memory 306a. Therefore, when the vehicle model indicated by the vehicle model information supplied from the operation unit 305 is not registered in the memory 306a, the installation position acquisition unit 306 may sequentially output a test sound to the speakers SP of each speaker set 20a to 20d, and identify the installation position of each microphone M1 to M4 based on a comparison of the phase or amplitude of each microphone reception signal (Sa1 to Sa4, Sb1 to Sb4, Sc1 to Sc4, Sd1 to Sd4) obtained by receiving the sound with the microphones M1 to M4 installed in each speaker SP with the original signal of the test sound.

[0067] In addition, in the example of the sound source direction detection system 100 shown in Figures 1 and 2, the sound source direction is detected based on 16 microphone signals obtained by receiving sound with a total of 16 microphones consisting of four microphones M1 to M4 installed on each of the four speakers SP.

[0068] However, the number of such speakers with microphones SP is not limited to four, and may be four or more, or one to three.

[0069] Furthermore, as long as the sound source direction detection system 100 has at least four microphones installed on multiple speakers SP, the multiple speakers SP may include speakers SP without microphones. In other words, it is sufficient that at least four microphones are installed on one or multiple speakers SP. In other words, it is sufficient that at least four microphones are installed in total throughout the vehicle. In this case, the sound source direction detection unit 30 detects the sound source direction based on a group of microphone reception signals obtained by receiving sound with at least four microphones in total and the installation positions of each microphone.

[0070] Furthermore, when four or more speakers SP are employed as the sound source direction detecting system 100, it is sufficient that at least one microphone is installed on each speaker SP of the speaker sets 20a to 20d.

[0071] For example, as shown in Fig. 7, only a single microphone M1 is installed on the frame fm of each speaker SP of the speaker sets 20a to 20d. In this case, it is preferable that the microphone M1 is installed on the frame fm of the speaker SP so that the height position of each microphone M1 from the floor of the vehicle interior is different when each speaker SP is attached to the corresponding speaker fixing part MPa to MPd. For example, as shown in Fig. 7, the height position of the microphone M1 installed on the speaker SP of each speaker set 20a to 20d from the floor of the vehicle interior is 20a M1:h1 M1:h2 of 20b M1:h3 of 20c Let's say M1:h4 in 20d.

[0072] That is, when the distances from three of the four microphones (M1) installed on speaker sets 20a to 20d to the sound source are the same, two directions that are normal to the imaginary plane that includes the three microphones can be candidates for the direction of the sound source. However, by installing one of the four microphones so that its installation point is not included in the imaginary plane defined by the installation points of the other three microphones, the distances to the sound source from the three microphones included in the imaginary plane and the distance to the sound source from the other microphone that is not on the imaginary plane will necessarily be different, making it possible to determine which of the two candidate sound source directions is the correct sound source direction. This makes it possible to improve the accuracy of detecting the sound source direction.

[0073] In other words, in order to further improve the accuracy of detecting the direction of the sound source, the installation point on the three-dimensional coordinate system of, for example, one microphone M1 out of the four microphones M1 to M4 installed on each of the four or more speakers SP may be set to a position that is not included on the plane defined by the installation points of the other microphones M2 to M4.

[0074] Also, for example, as shown in FIG. 8, only two microphones M1 and M3 may be installed on the frame fm of each speaker SP of the speaker sets 20a to 20d. In this case, the microphones M1 and M3 are installed on the surface of the frame fm of each speaker SP, on a diagonal line sandwiching the vibrating body dp. Furthermore, in a state where the pair of microphones (M1, M3) are attached to the respective speaker fixing parts MPa to MPd, the microphones M1 and M3 are installed on the frame fm of the speaker SP so that the height positions of the pair of microphones (M1, M3) from the floor of the vehicle interior are different. For example, as shown in FIG. 8, the height positions of the pair of microphones (M1, M3) installed on the speaker SP of each speaker set 20a to 20d from the floor of the vehicle interior are 20a M1, M3:h1, h8 M1, M3:h2, h7 in 20b 20c M1, M3:h3, h6 20d M1, M3:h4, h5 Let's say.

[0075] In the above embodiment, no mention is made of the surface shape of the frame fm of the speaker SP on which each microphone (M1 to M4) is installed, but the surface area of ​​the frame fm on which at least one of the multiple microphones is installed may be concave or convex.

[0076] For example, as a speaker SP, as shown in Figure 9, the surface of area AR1 in frame fm where microphone M1 is installed has one of a concave and a convex shape, and the surface of area AR2 where microphones M2 to M4 are installed has the other of a concave and a convex shape.

[0077] Fig. 10A is a diagram showing the surface configuration of frame fm of speaker SP shown in Fig. 9, when region AR1 of the frame fm is convex and region AR2 is concave, as viewed from the direction of the white arrow in Fig. 9. Also, Fig. 10B is a diagram showing the surface configuration of frame fm of speaker SP, when region AR1 of the frame fm is concave and region AR2 is convex, as viewed from the direction of the white arrow in Fig. 9.

[0078] As shown in Fig. 10A, when the surface of area AR2 is convex and the surface of area AR1 is concave, the position of the sound receiving surface (vibrator) of each of microphones M2 to M4 is closer to the sound source than microphone M1. On the other hand, as shown in Fig. 10B, when the surface of area AR2 is concave and the surface of area AR1 is convex, the position of the sound receiving surface of each of microphones M2 to M4 is farther from the sound source than microphone M1.

[0079] In other words, by installing microphones M1 to M4 on speaker SP in the form shown in Figure 9, Figure 10A or Figure 10B, the installation point (three-dimensional coordinates) of one of the four microphones M1 to M4, microphone M1, is not included in the plane defined by the installation points of the other three microphones M2 to M4.

[0080] This makes it possible to make this distance different from the distance from the sound source to the microphone M1, even if the distance from the sound source to the sound receiving surface of each of the three microphones M2 to M4 is the same, thereby improving the accuracy of detecting the direction of the sound source.

[0081] In short, the sound source direction detection system 100 for detecting the direction of a sound source inside or outside a vehicle may include a speaker group including at least one speaker (SP), each of which can be attached to a speaker fixing part (e.g., MPa to MPd) inside the vehicle cabin and on which a plurality of microphones (e.g., M1 to M4) are installed, and the following microphone installation position acquisition part and direction detection part. The microphone installation position acquisition part (306) identifies the installation position of each microphone based on the installation position of the speaker fixing part, and acquires microphone installation position information indicating the installation position of each microphone. The direction detection part (30) detects the direction of the sound source based on microphone reception signals (e.g., Sa1 to Sa4, Sb1 to Sb4, Sc1 to Sc4, Sd1 to Sd4) obtained by receiving sound with each of the plurality of microphones, and the installation positions of each microphone indicated by the microphone installation position information.

[0082] Furthermore, the speaker with microphone used in the sound source direction detection system 100 may be any one that includes a speaker (SP) that outputs sound corresponding to an audio signal received via a speaker cable (e.g., SC1), first to Nth (N is an integer of 2 or more) microphones (e.g., M1 to M4) installed on the speaker, and a microphone sound superimposition unit (MSP) that superimposes the first to Nth microphone sound signals (e.g., s1 to s4) obtained by receiving sound with the first to Nth microphones onto the speaker cable. [Explanation of symbols]

[0083] 10 Audio Equipment 20a~20d Speaker Set 30 Sound source direction detection unit 304 Direction detection circuit 305 Operation section 306 Installation position acquisition part M1~M4 microphones MSP microphone sound superimposition unit SP speaker

Claims

1. A sound source direction detection system for detecting the direction of a sound source inside or outside a vehicle, a speaker group including at least one speaker that can be attached to a speaker fixing portion in the interior of the vehicle; a plurality of microphones installed in the speaker group; a microphone installation position acquisition unit that identifies the installation position of each of the microphones based on the installation position of the speaker fixing unit and acquires microphone installation position information indicating the installation position of each of the microphones; a direction detection unit that detects the direction of the sound source based on microphone reception signals obtained by receiving sound from each of the plurality of microphones and the installation positions of each of the microphones indicated by the microphone installation position information.

2. an operation unit for receiving an operation to designate the type of the vehicle; 2. The sound source direction detection system according to claim 1, wherein the microphone installation position acquisition unit identifies the position of each of the microphones based on the installation position of the speaker fixing unit corresponding to the type of the vehicle.

3. 3. The sound source direction detecting system according to claim 1, wherein the at least one speaker is four or more speakers, each of which is provided with at least one of the microphones.

4. 4. The sound source direction detecting system according to claim 3, wherein four microphones are provided for each of the four or more speakers.

5. 4. The sound source direction detecting system according to claim 3, wherein two microphones are provided for each of the four or more speakers.

6. The sound source direction detection system according to claim 4 or 5, characterized in that two of the microphones installed on each of the speakers are installed on diagonal lines sandwiching the vibrating body of the speaker on which they are installed.

7. The sound source direction detection system according to any one of claims 3 to 6, characterized in that one microphone is installed for each of the four or more speakers at different heights from the vehicle floor.

8. A sound source direction detection system according to any one of claims 3 to 7, characterized in that one microphone is installed for each of the four or more speakers, and the installation point of one of the four installed microphones is not included in a plane defined by the installation points of the other three microphones.

9. A sound source direction detection system for detecting the direction of a sound source inside or outside a vehicle, a speaker that can be attached to a speaker fixing portion in the interior of the vehicle; at least four microphones located on a first one of the speakers; a microphone installation position acquisition unit that identifies the installation position of each of the four microphones based on the position of the speaker fixing unit and acquires microphone installation position information indicating the installation position of each of the microphones; a direction detection unit that detects the direction of the sound source based on each of the microphone reception signals received by the four microphones and the installation positions of the microphones indicated by the microphone installation position information, A sound source direction detection system characterized in that one of the four microphones is installed in a position in an area not included in the plane defined by the installation points of the other three microphones.

10. The sound source direction detection system of claim 9, characterized in that the surface of the frame around the edge portion of the first speaker includes a convex area and a concave area, three of the four microphones are installed in one of the convex area and the concave area, and one microphone other than the three microphones is installed in the other of the convex area and the concave area.

11. A speaker set included in a sound source direction detection system that detects the direction of a sound source inside or outside a vehicle based on microphone reception signals received by each of a plurality of microphones installed in a vehicle cabin and installation positions of each of the plurality of microphones, A speaker set characterized in that a speaker that can be attached to a speaker fixing part provided at a predetermined position in the interior of the vehicle is equipped with a plurality of microphones whose installation positions are identified based on the position of the speaker fixing part.

12. a connector for receiving a plurality of microphone-received signals obtained by receiving sounds from a plurality of microphones installed in a speaker group including at least one speaker that can be attached to a speaker fixing portion inside a vehicle; a microphone installation position acquisition unit that identifies an installation position of each of the microphones based on an installation position of the speaker fixing unit and acquires microphone installation position information indicating the installation position of each of the microphones; a direction detection circuit that detects the direction of a sound source inside or outside the vehicle based on the plurality of microphone reception signals received by the connector and the installation positions of the plurality of microphones indicated by the microphone installation position information; A sound source direction detecting device comprising:

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