JP2000075014A - Sound source search method - Google Patents

Abstract

(57) [Summary] By reproducing sound pressure data measured at each measurement point by a plurality of microphones arranged on a measurement surface for a sound source or a microphone scanning the measurement surface, the sound source surface is reproduced as a reproduction surface. In a sound source search method for searching for a position of a sound source, it is possible to easily associate a coordinate system between a sound source surface and a reproduction surface. A laser beam (LM) from a laser light emitter (LS) provided on a measurement surface (K) for marks (P1, P2) on a target object of a sound source.
To read the coordinates of the mark, and to display the coordinate points of the mark on the sound source distribution map on the reproduction surface, or to display the image of the sound source object on the sound source distribution map and display the image of the object. And the mark on the sound source distribution are matched.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound source searching method, and more particularly to a method for searching for a position and a size of a noise source in a vehicle engine or the like.

[0001]

2. Description of the Related Art Conventionally, various methods for searching for a sound source have been proposed. One of the methods is to place two scanning microphones at a fixed distance of about 6 to 50 mm before and after the sound source direction. By providing a microphone output while moving both scanning microphones in parallel in the near sound field of the sound source,
There is a method of obtaining the sound intensity of the sound source (“sound intensity method”).

In this method, there is no correlation since the measurement results at the respective scanning microphone measurement points are independent of each other. Therefore, when the direction of the sound source is not parallel to the extension of the microphone, there is a problem that a correct search cannot be performed. .

[0003] On the other hand, a sound source search method based on the "acoustic holography method" has been studied before the above-mentioned sound intensity method, and one microphone that scans a measurement plane at a certain distance from the sound source and another microphone. A sound source is searched for by obtaining sound pressure intensities and phases of two microphone output signals with a reference (reference) microphone fixed at an appropriate position.

FIG. 8 shows a conventional example of such a sound source search method (disclosed in Japanese Patent Application No. 7-202988 filed by the present applicant). The scanning microphones M _{11 to} M ₅₈ are arranged in a matrix.

[0005] These scanning microphones M₁₁~ M₅₈Is sound source S
When these sound pressures are received, their output signals are
A₁₁~ A₅₈To each amplifier A₁₁
~ A ₅₈A / D converter C provided corresponding to₁₁~ C
₅₈Is converted from an analog signal to a digital signal at
You.

The output signals of the A / D converters C _{11 to} C ₅₈ are sent to a holographic operation unit HC constituted by a personal computer or a work station to perform a predetermined acoustic holographic operation.

[0007] The result of the calculation by the holographic calculation unit HC is sent to a display D such as a CRT or a plotter, and the sound source distribution map is displayed.

FIG. 9 shows a conventional example of another sound source search method (also disclosed in Japanese Patent Application No. 7-202988 filed by the present applicant), in which multiple points are arranged as in the embodiment shown in FIG. Instead of using a scanning microphone, a single scanning microphone M1 and a fixed reference microphone M2 are used for the measurement surface K, and the scanning microphone M1 is horizontally moved on the measurement surface K with respect to the sound source S by the microphone traverse device TVS. It is attached to support rods B1 and B2 to be moved.

Since the support rod B1 can move on the support rod B2, the scanning microphone M1 is eventually turned on.
Are scanned in the horizontal and vertical directions on the measurement plane K, respectively.

The sound pressure outputs of the scanning microphone M1 and the reference microphone M2 are amplified by amplifiers A1 and A2, respectively.
After being converted into digital signals by the / D converters C1 and C2, a predetermined acoustic holographic operation is performed by a holographic operation unit HC in a computer PC such as a personal computer or a workstation, and the sound source distribution is displayed on a display D such as a CRT or a plotter. The figure will be displayed.

In this case, the microphone traverse device T
The controller CNT for controlling the VS is also controlled by a control software unit CS provided in the computer PC. The moving speed of the microphone traversing device TVS controlled by the controller CNT is obtained by sampling the output of the microphone M1. The speed is adjusted in advance.

[0012]

In the sound source searching method as described above, an arbitrary coordinate point on a measurement surface constituted by moving a microphone or a multi-point arrangement and a corresponding coordinate point on an actual sound source reproduction surface are determined. The association is important for ensuring the accuracy of the sound source search.

[0013] However, in the past, a human had manually measured using a long stick, a thread, or an extendable ruler. However, when the distance between the sound source and the microphone was long, the accuracy was insufficient, and work by multiple persons was required. There is a problem that it is necessary and takes a long time.

Accordingly, the present invention provides a sound source by reproducing sound pressure data measured at each measurement point by a plurality of microphones arranged on a measurement surface for a sound source or a microphone scanning the measurement surface, using the sound source surface as a reproduction surface. It is an object of the present invention to make it possible to easily associate a coordinate system between a sound source surface and a reproduction surface in a sound source search method for searching for the position of.

[0015]

Means for Solving the Problems [1] In order to solve the above problems, in the sound source search method according to the present invention, laser light from a laser emitter provided on a measurement surface is provided at a mark on an object of a sound source. The coordinates of the mark are read, and the mark is synthesized and displayed on the sound source distribution map on the reproduction surface.

That is, in the present invention, a mark is previously determined on the object of the sound source. Then, the coordinates of the mark at this time are read by irradiating the mark with laser light from a laser emitter mounted on the measurement surface.

By synthesizing and displaying the coordinates of the mark on the sound source distribution map on the reproduction surface obtained by the holographic operation, at least one portion of the sound source object can be associated with the sound source distribution, and the sound source can be located on any side. It becomes easy to recognize whether it exists.

[2] In the present invention, the number of marks required to represent the shape of the object is read as the above-mentioned marks, the coordinates of each mark are read, and the marks are connected to each other by line connection. The object shape may be synthesized and displayed on the sound source distribution map on the reproduction surface.

That is, in the present invention, a plurality of landmarks are previously attached to a sound source object. These mark marks are provided so as to represent the shape of the object of the sound source. Then, by irradiating the laser beam from the laser light emitting device to the mark, the coordinates of each mark at this time are read in the same manner as described above.

The coordinates of the mark marks read in this way are connected by, for example, a straight line. Then, the sound source distribution map on the reproduction surface is displayed, and the shape of the object in which the respective mark marks are directly connected is synthesized and displayed. This makes it easy to confirm where the distribution map of the sound source reproduction plane actually corresponds to the target of the sound source.

[3] According to the present invention, the coordinates of each mark are read by applying laser light from a laser emitter provided on the measurement surface to two predetermined marks on the object of the sound source, and the reproduction is performed. It is possible to display on the sound source distribution map of the surface and display the image of the object on the sound source distribution map of the reproduction surface, and to further match the mark of the object image with the mark on the sound source distribution map. It is.

That is, in the present invention, a mark is previously determined on the object of the sound source in the same manner as in the above-mentioned inventions [1] and [2], but two marks may be used. Then, a laser beam from a laser light emitter provided on the measurement surface is applied to each mark to read the coordinates, and then displayed on a sound source distribution map on the reproduction surface.

On the other hand, as for the object of the sound source, an image photographed by, for example, a camera or the like is displayed on the sound source distribution map on the reproduction surface.
At this time, the coordinate points obtained by reading the two marks are also displayed at the same time. Since the mark is also displayed on the object image at the same time, the mark is matched with the mark on the sound source distribution map.

By doing so, the image of the sound source object is also displayed on the sound source distribution map on the reproduction surface in this case, so that it is easy to determine where the sound source exists in the object. You can check it.

[4] The laser emitter may be mounted on the same mount as the microphone. [5] Further, the mark of the target object image and the mark on the sound source distribution map can be matched by enlarging and rotating on the screen.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of the configuration of an apparatus used when implementing a sound source search method according to the present invention. The difference from the conventional example shown in FIG. 9 is the same as that of the scanning microphone M1. A laser light emitter LS is provided on a base of the controller CNT.
The difference is that coordinate data when the traverse device TVS is moved is given to the display (CRT or plotter) D. Note that the scanning microphone M1 and the laser light emitter L
S need not necessarily be on the same gantry, and both need only be on the measurement plane K.

Also, marks P1 and P2 serving as marks are attached to the sound source target S in advance. It is preferable that these mark marks P1 and P2 are selected at positions separated from each other. Further, if the sound source object S itself can represent a specific point by its shape or color, it is not necessary to select that point and add a mark.

FIG. 2 shows a diagram in which two landmarks P1 and P2 are set for the sound source object S. This diagram is obtained when the measurement surface K shown in FIG. 1 is viewed as a window. In the side view of the engine ENG, the mark P1 is set at the connection point between the head cover HC and the cylinder block CB,
An example is shown in which the mark P2 is set at the right connection point between the cylinder block CB and the oil pan OP.

As described above, the engine E
When looking at NG, the laser beam L
Since M travels straight ahead, unlike when viewed by the human eye, there is no perspective, and the side coordinate system of the engine ENG is irrelevant to the distance from the measurement plane K.

In FIGS. 1 and 2, the mark P
Although two points 1 and P2 are provided, one mark may be used for associating the coordinates of the measurement surface with the coordinates of the sound source target S. As described above, after setting the mark marks P1 and P2 on the sound source target S, the coordinate axes of the sound source target S and the coordinate axes of the measurement plane K are set in parallel, and the measurement plane K is aligned with the center line of the sound source target S. Set to be parallel to.

Next, the laser light emitter LS fixed at the same position as the scanning microphone M1 is moved by the traverse device TVS via the pointing rods B1 and B2. In this case, a method of manually moving and a method of moving the controller CN from the control unit CS.
There is a method of automatically moving through T.

Then, when the traverse device TVS is moved and the laser beam LM of the laser light emitter LS comes to a position where it hits the mark P1, for example, the laser light emitter LS
, That is, the position of the scanning microphone M1 is read from the (X, Y) coordinates displayed on the controller CNT, and data is input from a keyboard (not shown) of the computer PC. The data of the (X, Y) coordinates may be automatically given to the display D from the controller CNT.

Next, the laser beam LM is similarly moved to hit the second mark P2, the position at that time is displayed on the controller CNT, and the coordinate value is read. The mark marks P1 and P2 on the sound source target S
Whether or not the position of the laser light LM on the measurement surface K is coincident with the human eye is visually determined. Therefore, the laser light LM is preferably visible light such as red. Therefore, a light-weight, small-sized, low-output light-emitting device such as a semiconductor laser may be used.

Since the coordinates of the mark marks P1 and P2 have been read by the controller CNT in this manner, the coordinates are displayed on the display D. In addition, (X,
Y) When the coordinates are automatically given, the points of the mark marks P1 and P2 are automatically displayed on the screen of the display D.

On the other hand, the scanning microphone M1 and the reference microphone M2
The holographic sound source distribution map on the reproduction surface obtained in the same manner as in the conventional example of FIG. 9 using FIG. 9 is a contour map as shown in FIG. 3, and usually only such a holographic sound source distribution map is displayed. .

However, according to the present invention, when the mark marks P1 and P2 are combined and shown in the holographic sound source distribution diagram, that is, when the mark marks P1 and P2 are combined and shown in FIG. Is displayed on the measurement surface K.

In the above embodiment, the image shown in FIG. 2 and the image shown in FIG. 3 are combined. However, the shape image of the engine ENG is not actually displayed as shown in FIG.
Since only the mark marks P1 and P2 provided on G and the holographic sound source distribution map are displayed, the shape of the engine ENG is difficult to understand.

Therefore, if the mark is set so as to be individually provided at a linear end of the engine ENG, for example, it is not an image of the engine ENG itself as shown in FIG. Engine image is synthesized with the holographic sound source distribution map,
The sound source distribution of the engine ENG is displayed more easily.

Further, in the present invention, the coordinate axes of the sound source and the coordinate axes of the measurement surface can be associated with each other by an embodiment different from the above. This will be described below with reference to FIGS. First, an image Is of the sound source target S as shown in FIG. 6 is captured by, for example, a digital camera or the like, and the image data is taken into the computer PC (step S in FIG.
1).

In the case of the sound source object S shown in FIG. 6, since its coordinates are on the sound source object S, its (x, y) coordinates are displayed on the display D connected to the computer PC as shown in FIG. The coordinates are different from the coordinates of the screen, that is, the (X, Y) coordinates of the measurement surface K. Therefore, the mark marks P1 and P2 set on the sound source target S also exist on the (x, y) coordinates.

Thereafter, the computer PC sets a holographic measurement coordinate system (S2). This is a step in which the computer PC sets a coordinate system for performing the holographic operation by the holographic operation unit HC in order to obtain the holographic sound source distribution map as shown in FIG.

Thereafter, the image of the sound source target S is appropriately displayed so that the sound source target S is appropriately displayed on the (X, Y) coordinates of the measurement surface K, which is a holographic reproduction surface, as shown in FIG. It is moved and tentatively determined (S3). Next, the mark mark P provided on the sound source target S in the same manner as in the above embodiment.
1 and P2 are irradiated with the laser light LM from the laser light emitter LS, and the coordinate points at that time are displayed on the measurement surface K (see FIG.
4). Since the coordinates at this time are on the coordinates of the measurement surface K by the laser light emitter LS, they are points P1 'and P2' different from the mark marks P1 and P2.

As a result, as shown in FIG. 7A, coordinate points P1 'and P2' on the reproduction measurement surface are simultaneously displayed on the captured image Is of the sound source object S. Thereafter, the object image Is is entirely moved such that the image of the mark P1 on the sound source object S matches the coordinates of the coordinate point P1 'on the reproduction surface (step S5). As a result, a combined image in which the points P1 and P1 'coincide with each other is obtained as shown in FIG.

Thereafter, the mark P2 of the sound source S coincides with the coordinate point P2 'on the measurement surface K while maintaining the state shown in FIG. 2B, that is, the state where the points P1 and P1' coincide. Then, the object image Is is enlarged and rotated (step S6). This enlargement / rotation technique is well known in current software technology.

As a result, as shown in FIG.
A composite image in which 1 and P1 'match and points P2 and P2' match is obtained. Thereafter, the computer PC drives the holographic operation unit HC, the control unit CS, and the like, thereby driving the scanning microphone M1 and the reference microphone M1, as in the above embodiment.
Then, a holographic sound source distribution chart (see FIG. 3) is displayed based on the sound pressure data from Step 2 (S7).

Thus, the final result synthesized in the same manner as in FIG. 4 is obtained. In the case of this embodiment, for example, the sound source distribution can be easily visualized in a similar-shaped image in which the outer shape of the engine differs only in the scale.

[0047]

As described above, according to the sound source searching method according to the present invention, a laser beam emitted from a laser emitter provided on a measurement surface is applied to a mark on a target object of a sound source, and the coordinates of the mark are obtained. Is read, and the coordinate points of the mark are combined and displayed on the sound source distribution map on the reproduction surface, or the image of the sound source object is combined and displayed on the sound source distribution map, and the mark of the object image and the sound source distribution are displayed. Since the mark is made to coincide with the mark, it is possible to perform accurate association between the sound source surface and the measurement surface in a short time by one person.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment (microphone moving method) of a sound source search method according to the present invention.

FIG. 2 is a block diagram showing the appearance of an engine as a sound source target and a mark mark set on the engine in the same (X, Y) coordinates as a measurement surface.

FIG. 3 is a diagram showing a holographic sound source distribution on a measurement surface.

FIG. 4 is a diagram showing a final image obtained by synthesizing a sound source object and a holographic sound source distribution map.

FIG. 5 is a flowchart of an embodiment in which a coordinate system is associated using an image of a sound source target in the sound source search method according to the present invention.

FIG. 6 is a diagram showing an example of an image of a sound source target.

FIG. 7 is a graph illustrating a process of correcting a coordinate position in the sound source search method according to the present invention.

FIG. 8 is a diagram showing one embodiment of a multi-point microphone system used in a conventional sound source search method.

FIG. 9 is a diagram showing a microphone moving method which is an embodiment of a conventional sound source search method.

[Explanation of symbols]

During LS laser emitter LM laser light P1, P2 landmark mark M1 scanning microphone M ₁₁ ~M ₅₈ Microphone M2 reference microphone S source K measurement plane TVS microphone traverse device HC holography calculation section view, the same reference numerals denote the same or corresponding parts.

Continued on the front page F term (reference) 2G064 AA15 AB02 AB03 AB06 AB15 AB18 BA02 BA22 BC03 BC32 BD02 CC13 CC18 CC29 DD08 DD14 2K008 JJ00 5J083 AA05 AB12 AC28 AC30 AD02 AD18 AE01 AG05 BD03 CA10 CA13 EA03 EA10 EA28 EB05

Claims (5)

[Claims] The sound source position is determined by reproducing sound pressure data measured at each measurement point by a plurality of microphones arranged on a measurement surface for a sound source or a microphone scanning the measurement surface, using the sound source surface as a reproduction surface. In the sound source searching method for searching, the coordinates of the mark are read by applying a laser beam from a laser light emitting device provided on the measurement surface to the mark on the object of the sound source, and the mark is displayed on the sound source distribution map of the reproduction surface. A sound source search method characterized by displaying images in a combined manner. 2. The object according to claim 1, wherein the number of marks necessary for representing the shape of the object is read as the mark, the coordinates of each mark are read, and a line connection is made between the mark marks. A sound source search method characterized in that a shape is synthesized and displayed on a sound source distribution map on the reproduction surface. 3. The sound source position is reproduced by reproducing sound pressure data measured at each measurement point by a plurality of microphones arranged on a measurement surface for a sound source or a microphone scanning the measurement surface, using the sound source surface as a reproduction surface. In the sound source searching method for searching, the coordinates of each mark are read by applying laser light from a laser light emitting device provided on the measurement surface to two predetermined marks on the object of the sound source, and the coordinates of each mark are read. Displaying and compositing and displaying the image of the object on the sound source distribution map of the reproduction surface,
A sound source search method, further comprising: matching a mark on the object image with a mark on the sound source distribution map. 4. A sound source search method according to claim 1, wherein said laser light emitter is mounted on the same mount as said microphone. 5. The sound source search method according to claim 3, wherein the mark of the object image and the mark on the sound source distribution map are matched by enlarging and rotating on a screen.