JP2007180953A - Mobile sound source searching apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile sound source searching apparatus that efficiently discovers an extremely weak voice and sound generated by living people in a disaster or accident site to thereby support the searching and rescue work of the living people. <P>SOLUTION: The mobile sound source searching apparatus is equipped with: a microphone array (MA) unit 1; an arm 2 for supporting the MA unit 1; a data conversion unit 3 that applies A-D conversion to a multichannel signal received from the MA unit 1; a data reception section 5 for wirelessly receiving a data signal from the data conversion section 3; a signal processing section 6 for controlling a delay time of the received data signal by each channel so as to allow the MA unit 1 to develop sharp directivity and outputting a composite signal resulting from selectively composing sounds arrived in optional directions; and an acoustic output section 8 for applying D-A conversion to the composite signal outputted from the signal processing section 6 and reproducing the resulting signal as an acoustic signal, wherein the MA unit 1, the arm 2, the data conversion section 3, and a data transmission section 4 are integrally arranged in a carriable way. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a portable sound source search device using information communication equipment, and more specifically, a portable sound source search device including a portable super-directional microphone using three-dimensional acoustic technology, signal processing technology, and the like. About.

  In order to save as many lives as possible in a disaster-stricken area, it is important to quickly find survivors. As tools to support the search for survivors, devices such as underground sounders developed for the purpose of lifesaving and the like, and a camera / microphone / speaker / light integrated at the tip of a telescopic rod have been proposed. (Patent Document 1). However, since the range that can be searched at one time is limited and sounds coming from unspecified directions are mixed, it is considered that the usefulness under noise is poor.

  The microphone array is effective as a means for measuring acoustic information three-dimensionally, and is a method of extracting only a specific speaker's voice from a plurality of speakers mainly in a noisy environment or in a video conference system. (Patent Document 2), research is being conducted as an element technology of a speech recognition device and a robot (Non-Patent Documents 1 and 2). The directivity and spatial sensitivity characteristics of the microphone array can be controlled by signal processing.

US20010055544A1 Special Table 2004-528766 J.-M. Valin, F. Michaud, J. Rouat, and D. L´etourneau, “Robust sound source localization using a microphone array on amobile robot,” inProc. IROS, 2003 Yasuaki Ohashi, Tsuyoki Nishikawa, Hiroshi Saruwatari, Akinobu Lee, Kiyohiro Shikano, `` Noise Robust Speech Recognition Based on Spatial Subtraction Array, '' Proceedings of International Workshop on Nonlinear Signal and Image Processing (NSIP2005), pp324-327, May 2005

  In areas affected by natural disasters such as earthquakes and typhoons and areas damaged by large-scale accidents, it is necessary to quickly find survivors. At this time, the voices and sounds produced by the survivors are important clues. Sound is the biggest clue, especially when the field of view is limited by obstacles such as rubble. Therefore, there is a means to amplify the sound collected by a unidirectional microphone or an omnidirectional microphone and the searcher can listen to it with headphones, etc., but in the case of a unidirectional microphone, only one direction can be searched at a time. Is bad. In addition, in the case of an omnidirectional microphone, signals coming from unspecified directions are mixed together, and thus are strongly influenced by external noise.

  On the other hand, if a microphone array is used, sharp directivity can be generated in an arbitrary direction by signal processing, so that there is a high possibility that a minute signal can be found even under noise. In the case of a unidirectional microphone, the microphone itself must be directed in the direction in which it is desired to search, but in the microphone array, an arbitrary direction can be searched without moving the microphone itself. In addition, since a plurality of independent directivities can be formed at the same time, a wide area can be searched efficiently.

  An object of the present invention is to provide a portable sound source search device capable of accurately finding a sound source at various disaster sites, whether indoors or outdoors, by making a microphone array having the above-mentioned advantages portable. There is to do.

In order to solve the above problems, the present invention employs the following means.
The first means includes a microphone array unit composed of a plurality of microphones, an arm unit that supports the microphone array unit, and a data conversion unit that converts a multi-channel analog signal input from the microphone array unit into a digital signal. A data transmission unit that wirelessly transmits a data signal output from the data conversion unit, a data reception unit that receives a data signal transmitted from the data transmission unit, and the microphone array unit exhibiting sharp directivity, A signal processing unit for manipulating a delay time for each channel of the data signal received by the data receiving unit and outputting a synthesized signal obtained by selectively synthesizing sounds coming from an arbitrary direction, and outputting from the signal processing unit And an acoustic output unit that converts the synthesized signal into an analog signal and reproduces it as an acoustic signal. Parts, the arm portion, the data conversion unit, and the data transmission unit is a portable sound source search apparatus characterized by being configured to be portable together.
A second means is the portable sound source search device according to the first means, wherein the data conversion unit and the data transmission unit are built in the arm unit.
A third means is a portable sound source searching device according to the first means or the second means, wherein the length of the arm portion is variable.
According to a fourth means, in any one of the first means to the third means, the data reception unit includes a data recording unit that compresses the data received by the data transmission unit and records the data in a storage medium. It is a portable sound source search device.
According to a fifth means, in any one of the first means to the fourth means, the microphone array unit includes an angle sensor unit that detects a first angle of the microphone array unit, and the arm unit includes An angle data transmitting unit configured to transmit the first angle detected by the angle sensor unit to the data receiving unit; the angle output unit configured to detect the second angle of the sound output unit and the second angle; And a headset unit including an angle data transmitting unit that transmits the data to the data receiving unit, and the signal processing unit detects a relative angle of the second angle received by the data receiving unit with respect to the first angle. And determining a search direction based on the detected angle, operating a delay time for each channel of the data signal received by the data receiver based on the determined search direction, and determining the determined direction. And a portable sound source search apparatus characterized by selectively synthesized by the sound coming from the search direction and outputs the combined signal.
A sixth means includes any one of the first means to the fifth means, and includes a plurality of the sound output units, and the signal processing unit independently creates a plurality of directivities, A portable sound source search device characterized by outputting a plurality of synthesized signals obtained by independently synthesizing sounds arriving from a plurality of different directions, and separately outputting the plurality of synthesized signals from the plurality of sound output units. It is.

  As described above, according to the present invention, a portable sound source search device that can be used at various disaster sites, whether indoors or outdoors, can be provided by using a portable microphone array that can arbitrarily control directivity.

  The sensitivity of the microphone array can be improved by increasing the number of microphones. For example, by placing several hundreds or more microphones at intervals of about several centimeters, high sensitivity that can capture even a small signal A portable sound source search device can be provided.

  The directivity of the microphone array is formed by signal processing, so if multiple signal processes are executed in parallel, multiple independent directivities can be created simultaneously, and multiple composites corresponding to each directivity can be created. It is possible to output a signal. By outputting multiple synthesized signals synthesized by parallel signal processing from the acoustic output unit, multiple listeners can listen and simultaneously search for multiple directions, thus efficiently searching a wide area It becomes possible.

BEST MODE FOR CARRYING OUT THE INVENTION

A first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a diagram showing a basic configuration of a portable sound source search device according to the invention of this embodiment.
In the figure, 1 is a microphone array unit, 2 is an arm unit, 3 is a data conversion unit built in the arm unit 2, 4 is a data transmission unit built in the arm unit 2, 5 is a data reception unit, and 6 is a signal. A processing unit, 7 is a data recording unit, and 8 is an acoustic output unit. The microphone array unit 1 is composed of a plurality of microphones 0,... N-1, a microphone mounting panel 9 to which the microphones are attached, and a plurality of amplifiers, and blocks unwanted sounds coming from the back of the microphone array as necessary. A sound insulating plate 10 is provided. There is no restriction | limiting in the shape of the microphone attachment panel 9, A square, a rectangle, a disk shape etc. can be considered.

As shown in the figure, the data conversion unit 3 and the data transmission unit 4 are built in and integrated with the arm unit 2 that supports the microphone array unit 1. The signal output from the sound output unit 7 is presented to the listener through a speaker or headphones.
In the figure, this portable sound source search device operates as follows. In the microphone array unit 1, acoustic signals acquired from the plurality of microphones 0,... N−1 are converted into multi-channel analog electric signals and sent to the data conversion unit 3. In the data converter 3, the sent analog signal is converted into a digital signal and wirelessly transmitted from the data transmitter 4. The data signal transmitted from the data transmission unit 4 is received by the data reception unit 5 and sent to the signal processing unit 6 and the data recording unit 7. The signal processing unit 6 controls the delay time of each channel of the data signal, and selectively extracts and synthesizes sound coming from any direction. The synthesized signal is converted into an analog signal in the sound output unit 8 and output through a speaker or headphones. In the data recording unit 7, the data signal sent from the data receiving unit 5 is compressed as necessary, recorded in a storage medium, and output to the signal processing unit 6 as necessary.

FIG. 2 is a diagram showing the configuration of the portable sound source search device according to the invention of this embodiment.
In the figure, reference numeral 11 denotes a control room portion in which a plurality of searchers 2, 3, and 4 are arranged in a soundproofed room, and the other configurations correspond to the configurations of the same symbols shown in FIG. To do.
This portable sound source search device operates as follows. First, one searcher 1 holds and operates the microphone array unit 1 supported by the arm unit 2. The data signal acquired by the microphone array unit 1 is wirelessly transmitted from the data transmission unit 4 built in the arm unit 2 and received by the data reception unit 5 provided in the control room unit 11. The received data signal is transmitted to the signal processing unit 6 or the data recording unit 7. In the signal processing unit 6, a plurality of independent directivities are obtained by calculation, and signals coming from different directions are synthesized separately. Each synthesized signal A, synthesized signal B, and synthesized signal C having different directivities are listened to by the headphones of each searcher 2, 3, 4 by the sound output unit 8 held by each searcher 2, 3, 4 Is done. As described above, since a plurality of listeners 2, 3, and 4 are separately listened in the control room section 11, a plurality of directions are searched at the same time, so that a wide area can be searched efficiently and quickly. it can. The control room 11 can be carried close to the search place, and the inside of the control room 11 is preferably as quiet as possible. As the control room unit 11, a vehicle-mounted container subjected to a soundproofing process can be considered. In addition, since the several directivity formed is independent, it does not interfere with each other.

Next, a second embodiment will be described with reference to FIGS.
FIG. 3 is a diagram showing the configuration of the portable sound source search device according to the invention of this embodiment.
In the figure, 12 is a headset unit, 13 is provided in the microphone array unit 1 or the arm unit 2, an angle sensor unit for detecting the angle of the microphone array unit 1 or the arm unit 2, and 14 is detected by the angle sensor unit 13. The angle data transmitting unit 15 transmits the measured angle to the data receiving unit 5, 15 is provided in the headset unit 12, an angle sensor that detects the angle of the headset unit 12, and 16 is the angle detected by the angle sensor unit 15. It is an angle data transmission unit that transmits to the reception unit 5. The other configurations correspond to the configurations with the same reference numerals shown in FIG.

  As shown in the figure, the angle detected by the angle sensor unit 13 provided in the microphone array unit 1 is transmitted from the angle data transmission unit 14 to the data reception unit 5. In addition, the headset unit 12 includes an acoustic output unit 8 that includes headphones that output the synthesized signal synthesized by the signal processing unit 6, and an angle sensor unit 15 that detects the angle of the headset unit 12. The angle is transmitted from the angle data transmission unit 16 to the data reception unit 5. Each angle received by the data receiving unit 5 is sent to the signal processing unit 6.

FIG. 4 is a diagram for explaining a scene in which the searcher 1 controls the directivity direction of the microphone array unit 1 by changing the direction of the head without moving the microphone array unit 1.
The method of detecting the angle by the angle sensor in the angle sensor units 13 and 15 is not particularly limited, but a magnetic sensor that detects a relative angle with respect to the geomagnetism is commercially available and can be used. For example, a commercially available angle sensor is attached to each of the angle sensor units 13 and 15 of the microphone array unit 1 and the headset unit 12 to detect a relative angle with respect to each geomagnetism. The difference between the angles detected by the angle sensors 13 and 15 is defined as θ. If the distance between adjacent microphones 0, 1,... I is r, the distance between the microphone 0 and the i-th microphone i is ir. The time difference from when the signal arriving from the direction of the angle θ to the microphone array unit 1 reaches the microphone 0 until it reaches the microphone i is obtained by dividing the distance irsin θ by the speed of sound c. By correcting this time difference irsin θ / c, the signal processing unit 6 can selectively extract and synthesize sounds coming from the direction in which the headset unit 12 is facing. The synthesized signal is converted into an analog signal by the sound output unit 8 and output from the headphones. Thus, the searcher 1 can control the directivity direction of the microphone array unit 1 by changing the direction of the head without moving the microphone array unit 1. Therefore, it is possible to search in a narrow space where the microphone array unit 1 cannot be moved freely.

  Also in the portable sound source search device of the present embodiment, sounds coming from any direction are selectively synthesized and output, but if the searcher himself is in a noise environment, a weak signal will be generated due to the influence of noise. Since there is a possibility that it cannot be heard, it is necessary to allow a plurality of searchers to listen to the synthesized signal in the control room 11 where the inside is quiet as in the portable sound source search device of the first embodiment. .

Here, processing performed by the signal processing unit 6 in the portable sound source search device of the first embodiment and the second embodiment will be described with reference to Equations 1 to 3 and FIG.
FIG. 5 shows the relationship between the microphone and the focus of the microphone array in the microphone array.

フォーカス位置Xは、マイクロホンアレイから見た方向と距離を指定することによって任意に決めることができる。式３からあきらかなように、マイクロホンの数が多いほど、目的とする信号は相対的に増幅されるため、鋭い指向性が得られる。 The distance l (m) that the sound wave travels during t (seconds) is obtained by the product of the sound velocity c (m / second) and the transmission time t (seconds) (Equation 1). Therefore, when the distance l is known, the transmission time t can be obtained from the distance l (Formula 2).

The focus position X can be arbitrarily determined by designating the direction and distance viewed from the microphone array. As is clear from Equation 3, as the number of microphones increases, the target signal is relatively amplified, so that sharp directivity is obtained.

  Search and rescue activities at the search site may be interrupted due to the effects of sunset or bad weather. In the first and second embodiments, a signal collected by the microphone array unit 1 and converted into a digital signal by the data conversion unit 3 is stored in the data recording unit 7, so that the search at the site is completed or the search is interrupted. In particular, it is possible to re-synthesize the signal based on the recorded signal and listen to it. At this time, a more detailed search can be performed by moving the focus little by little every time the signals are recombined.

  Although the basic embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Appropriate changes can be made without departing from the scope of the present invention.

It is a figure which shows the basic composition of the portable sound source search device which concerns on invention of 1st Embodiment. It is a figure which shows the structure of the portable sound source search apparatus which concerns on invention of 1st Embodiment. It is a figure which shows the structure of the portable sound source search apparatus which concerns on invention of 2nd Embodiment. It is a figure for demonstrating control of the directivity direction of the microphone array part by changing the direction of a head, without the searcher 1 moving the microphone array part. It is a figure which shows the relationship between a microphone array and its focus position.

Explanation of symbols

0,..., N-1 Microphone 1 Microphone array unit 2 Arm unit 3 Data conversion unit 4 Data transmission unit 5 Data reception unit 6 Signal processing unit 7 Data recording unit 8 Acoustic output unit 9 Microphone mounting panel 10 Sound insulation plate 11 Control room Unit 12 headset unit 13 angle sensor unit 14 angle data transmission unit 15 angle sensor 16 angle data transmission unit

Claims (6)

  A microphone array unit composed of a plurality of microphones, an arm unit that supports the microphone array unit, a data conversion unit that converts a multi-channel analog signal input from the microphone array unit into a digital signal, and the data conversion unit A data transmission unit that wirelessly transmits an output data signal, a data reception unit that receives a data signal transmitted from the data transmission unit, and the data reception unit so that the microphone array unit exhibits sharp directivity. A signal processing unit that operates a delay time for each channel of the received data signal and selectively synthesizes sounds arriving from an arbitrary direction, and an analog signal that is output from the signal processing unit. An acoustic output unit that converts the signal into a signal and reproduces the signal as an acoustic signal. Parts, the data conversion unit, and a portable sound source search system wherein the data transmission unit is characterized in that it is configured to be portable together.   The portable sound source search device according to claim 1, wherein the data conversion unit and the data transmission unit are built in the arm unit.   The portable sound source search device according to claim 1 or 2, wherein the length of the arm portion is variable.   The portable sound source search device according to any one of claims 1 to 3, further comprising a data recording unit that compresses data received by the data transmission unit and records the compressed data in a storage medium. .   The microphone array unit includes an angle sensor unit that detects a first angle of the microphone array unit, and the arm unit transmits an angle data transmission that transmits the first angle detected by the angle sensor unit to the data receiving unit. A signal processing unit, and a headset unit including an angle sensor unit that detects the second angle of the acoustic output unit, and an angle data transmission unit that transmits the second angle to the data reception unit. A unit detects a relative angle of the second angle received by the data receiving unit with respect to the first angle, determines a search direction based on the detected angle, and determines the determined search direction. Based on this, the delay time for each channel of the data signal received by the data receiving unit is manipulated to selectively synthesize sounds coming from the determined search direction and output a synthesized signal. To portable sound search apparatus according to any one of claims 1 to claim 4. A plurality of the sound output units, the signal processing unit outputs a plurality of synthesized signals obtained by independently synthesizing sounds coming from a plurality of different directions by independently creating a plurality of directivities, The portable sound source search device according to any one of claims 1 to 5, wherein the plurality of synthesized signals are separately output from the plurality of sound output units.

Images