JP4115864B2 - Moving object noise measurement apparatus, method and program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a noise measuring apparatus, method, program, and recording medium for a moving body that measures noise such as noise generated by a moving body such as a train or an automobile in association with the moving body.
[0002]
[Prior art]
As a method of measuring the noise generated by moving bodies such as trains, in order to associate the sound pressure data obtained by microphone measurement with the sound source surface and the reproduction surface, the mark of the sound source object is read with a laser beam, There has been a method of synthesizing the mark of the image of the sound source object and the mark on the sound source distribution (for example, Patent Document 1).
Further, there has been a method of measuring a two-dimensional sound source distribution of a moving sound source by arranging microphones two-dimensionally (for example, Patent Document 2).
Further, the position of the moving body is detected by a sensor, and an image or a figure of the moving body is prepared separately, and the image or the figure is enlarged / reduced and synthesized with the sound source distribution. For example, in the case of a train, a method of enlarging or reducing a separately prepared train image or figure to detect the passage of wheels and obtaining a scaled train image or figure corresponding to the train speed, and combining it with a sound source distribution (For example, Patent Document 3).
[0003]
[Patent Document 1]
JP 2000-75014 A [Patent Document 2]
Patent No. 2544535 [Patent Document 3]
Japanese Patent Laid-Open No. 2002-17015
[Problems to be solved by the invention]
However, in the conventional technique, it is necessary to mark the sound source object in order to clarify the coordinate system of the sound source object.
In addition, when the sound source object is a moving object, there is a problem that the mark moves and cannot be handled by laser light.
・ In addition, it was necessary to grasp the state of the moving body measuring the sound pressure distribution with a video camera installed separately. For that purpose, the vehicle type was noted. In the case of a test or the like, the vehicle may be temporarily installed, but it is necessary to record the temporary state.
・ To visualize the two-dimensional sound pressure distribution, it is necessary to prepare images and drawings of moving objects in advance and to enlarge and reduce the size of the images and drawings according to the size of the two-dimensional sound pressure distribution. Met.
[0005]
An object of the present invention is to solve the above-described problem, and an object thereof is to make it possible to visualize a noise generated by a moving body in association with an image of the moving body.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a moving object noise measuring apparatus according to the present invention measures an image pickup means for continuously picking up an image of a moving object a plurality of times along its moving direction, and noise generated by the moving object. A noise measuring means and a detecting means for detecting passage of a predetermined portion of the moving body are provided.
[0007]
Further, the noise measurement method for a moving body according to the present invention includes an imaging step of continuously imaging the moving body a plurality of times along its moving direction, a noise measurement step of measuring noise generated by the moving body, And a detection step of detecting passage of a predetermined portion of the moving body.
[0008]
Further, the program according to the present invention includes an imaging process for continuously imaging a moving body a plurality of times along the moving direction, a noise measurement process for measuring noise generated by the moving body, and a predetermined portion of the moving body. And a detection process for detecting the passage of the computer.
Furthermore, a recording medium according to the present invention records the above program.
[0009]
[Action]
Therefore, according to the present invention, the noise distribution is superimposed on the moving body image by processing the captured moving body image and the measured noise in synchronization with each other based on the signal obtained by detecting the predetermined position of the moving body. Can be displayed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a system configuration of a moving body noise measuring apparatus according to an embodiment of the present invention.
In the present embodiment, by measuring a two-dimensional sound pressure distribution of noise generated by a Shinkansen train, capturing a train image, and displaying the sound pressure distribution superimposed on the train image, for example, as shown in FIG. The level of noise generated from which part of the train is visually understood.
[0011]
In FIG. 1, 1 is a train on the Shinkansen that is a measurement target, 2 is an axle detection sensor that is provided at a predetermined position on the rail 3 and detects the passage of the axle of the train 1 and outputs an axle detection signal 4. Is performed electromagnetically or optically. 5 is a line sensor camera that captures images of the traveling train 1 from the side surface, 6 is an image processing unit that processes an image signal captured by the line sensor camera 5 based on the axle detection signal 4, and 7 is a storage of processed image data. The image storage unit.
[0012]
8 is an array microphone formed by arranging a plurality of microphones for two-dimensionally collecting the noise of the train 1, 9 is a sound processing unit for processing a sound signal obtained from the array microphone 8, and 10 is a processed sound. An audio storage unit for storing data, 11 is a sound pressure distribution calculation unit for calculating the sound pressure distribution by associating the image data of the image storage unit 7 and the audio data of the audio storage unit 10, and 12 is a process performed by the sound pressure distribution calculation unit 11. It is a display device such as a display or a printer that visually displays a train image with a sound pressure distribution superimposed on the trained data.
[0013]
Next, the operation according to the above configuration will be described.
The line sensor camera 5 is formed by arranging, for example, 1024 pixel image pickup devices in a line, and is used by arranging it in the vertical direction (direction perpendicular to the traveling direction of the train 1). The train 1 is imaged with the vertical direction as the main scanning direction and the traveling direction of the train as the sub-scanning direction. The captured image signal is processed by the image processing unit 6 together with the axle detection signal 4 and then stored in the image storage unit 7.
[0014]
On the other hand, the array microphone 8 is one in which a plurality of microphones are arranged, or for example, one in which about 100 microphones are arranged on a spiral plane or the like. Sound is collected two-dimensionally for each microphone. The collected sound signal is processed by the sound processing unit 9 and then stored in the sound storage unit 10 together with the axle detection signal 4.
Each data of the image storage unit 7 and the voice storage unit 10 is sent to a sound pressure distribution calculation unit 11 where calculation for obtaining a two-dimensional sound pressure distribution as described later in relation to the image of the vehicle body of the train 1 is performed. Is done.
[0015]
FIG. 2A shows a signal obtained by processing an image signal picked up by the line sensor camera 5, and a vertically long image obtained by partially picking up the train 1 for each line as shown in FIG. Has been obtained. In this case, assuming that a portion having a length of about 5 m (5000 mm) from the rail to the overhead line is imaged at a scanning speed of 52 μs using an image sensor of 1024 pixels, the moving length of the train 1 on the imaging surface is 4 .8 mm / pixel. Assuming that the train speed is 360 km / h (= 100 m / s = 100 mm / ms), the train 1 moves 5.2 mm during this period at 52 μs. Therefore, from the above 4.8 mm / pixel, it can be said that no image loss occurs at this train speed.
[0016]
Also, the train speed is t1 when the first image of the train 1 is collected, and t2 when the last image is collected. If the total length L of the train 1 is known,
Train speed = L / (t1-t2)
Can be obtained. When the train speed is high, the photographed train image is shortened. When the train speed is slow, the photographed train image is long, but it can be calibrated using the train speed or the known total train length L. it can.
[0017]
FIG. 2B shows the relationship between the train 1 and the axle detection signal 4.
In the present embodiment, in order to synchronize the image and the sound in the processing of the sound pressure distribution calculation unit 11, the passage timing of the axle that is a specific noise generation source of the train is used. That is, synchronization is achieved by starting counting the clock of the image and the sound using the axle detection signal 4 from the axle detection sensor 2 as a trigger. In addition, even if this synchronization is performed in real time at the time of measurement, the sound pressure data and the image data measured individually are synchronized with the detection of the axle (detection as an image and detection of the sound pressure) as a reference point. Also good. Further, the reference point may be appropriately corrected using data of not only the frontmost axle but also the following axle.
[0018]
The sound pressure distribution calculation unit 11 calculates the sound pressure distribution as follows. Since the direction of the sound source can be specified from the phase difference between the sound waves that reach each microphone of the array microphone 8 arranged on the plane, the position of the sound source can be calculated and specified. The position of each microphone is known from the reference height (for example, the traveling surface of the train (rail top surface)), and the distance to the sound source is clear from the sound pressure measured by the microphone. The sound pressure of the sound source can be calculated for each frequency component. The sound pressure distribution is created by obtaining the sound pressure for each frequency component and the position (coordinates) of the sound source that is distant from each other based on the positional relationship from the reference height of each microphone and the sound pressure of the sound source. Can do.
[0019]
As shown in FIG. 3, the sound pressure distribution obtained in this way and the train image are synthesized, and the axle detection signal 4 on the sound pressure distribution side and the axle detection signal 4 on the train image side are aligned. An image obtained by superimposing the sound pressure distribution of the sound source on the train image can be displayed on the display device 12. FIG. 3 shows a 500 Hz component noise as an example, and it can be seen that a large amount of noise is generated around the axle of the train 1 as shown. In practice, the shape of the sound pressure distribution becomes more complex as the frequency increases.
[0020]
In the present embodiment described above, the line sensor camera 5 is used, but a slit camera may be used. A slit camera has a slit plate with a slit on the exposure surface of the camera. With this slit placed perpendicular to the direction of train movement, the recording medium such as a slit plate or film is moved by the train. Take an image while moving in the direction. In this case, since the train is reflected upside down on the exposure surface, the moving direction of the recording medium is the opposite direction to the moving direction of the train. When imaging is performed in this manner, an image in which the background flows and the train is stationary is obtained.
[0021]
That is, the camera used in the present invention may be any camera that can continuously image a part of the moving body (train 1) a plurality of times along its moving direction. An image obtained by a slit camera can also be used. By imaging with such a camera, it is possible to obtain an image in which the moving body is divided into a plurality on the time axis as shown in FIG.
[0022]
Moreover, although this Embodiment demonstrated the case where a mobile body was a train, the mobile body may be vehicles, such as a motor vehicle, or another mobile body which emits some noise.
Moreover, although this Embodiment demonstrated the case where noise was made into noise, in this invention, measurement object noise may be a vibration, electromagnetic noise, etc. not only a noise.
[0023]
Next, a program according to the present embodiment and a recording medium for recording the program will be described.
The program for the CPU of the computer system in this apparatus to execute the processing based on the above-described operation of the mobile noise measuring apparatus shown in FIG. 1 constitutes a program according to the present invention.
[0024]
The recording medium for recording the program constitutes a computer-readable recording medium according to the present invention. As this recording medium, a magneto-optical disk, an optical disk, a semiconductor memory, a magnetic recording medium, or the like can be used, and these may be configured and used in a ROM, RAM, CD-ROM, flexible disk, memory card, or the like.
[0025]
In addition, this recording medium can store a program for a certain period of time such as a volatile memory such as a RAM in a computer system as a server or a client when the program is transmitted via a network such as the Internet or a communication line such as a telephone line. The thing to hold is also included.
[0026]
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. The transmission medium refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
[0027]
The program may be for realizing part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.
[0028]
Therefore, even when this program and recording medium are used in an apparatus or system different from the apparatus of FIG. 1 and the computer of the apparatus or system executes this program, the functions and effects equivalent to those described in the above embodiment are equivalent. Functions and effects can be obtained, and the object of the present invention can be achieved.
[0029]
【The invention's effect】
As described above, according to the present invention, the moving body is continuously imaged a plurality of times along the moving direction, noise generated by the moving body is measured, and a predetermined portion of the moving body is passed. The noise distribution is displayed in association with each part of the moving body by processing the captured image of the moving body and the measured noise synchronously based on the detection signal for detecting the predetermined portion. can do.
In that case, it is not necessary to prepare images and drawings of moving objects in advance as in the past, or to enlarge or reduce the size of images or drawings according to the size of the sound pressure distribution. Can be realized with simple work.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a moving object noise measurement apparatus according to an embodiment of the present invention.
FIG. 2 is a configuration diagram showing an image signal, an axle detection signal, and the like for explaining the operation of the moving object noise measurement apparatus according to the embodiment of the present invention.
FIG. 3 is a configuration diagram showing a display example of a train noise generation source.
[Explanation of symbols]
1: Train, 2: Axle detection sensor, 4: Axle detection signal, 5: Line sensor camera, 6: Image processing unit, 7: Image storage unit, 8: Array microphone, 9: Audio processing unit, 10: Audio storage unit 11: Sound pressure distribution calculation unit, 12: Display device

Claims (11)

Imaging means for continuously imaging a train as a moving body passing through a predetermined point multiple times along the moving direction;
Noise measuring means for measuring noise generated by the moving body;
Detecting means for detecting passage of a predetermined portion of the moving body ;
Noise correlated with the moving body image by processing the noise measured by the noise measuring means and the moving body image picked up by the imaging means while synchronizing them based on the detection signal obtained from the detecting means. A moving body noise measuring device comprising a calculating means for calculating a distribution . The mobile noise measurement apparatus according to claim 1 , further comprising display means for displaying the calculated noise distribution and the moving body image in an overlapping manner. 3. The noise according to claim 1, wherein the noise is noise, the noise measuring means is an array microphone in which a plurality of microphones are two-dimensionally arranged, and the calculating means calculates a sound pressure distribution. Mobile noise measurement device. The said detection means detects the passage of the axle of the train as the said mobile body, The noise measuring apparatus of the mobile body of any one of Claims 1-3 characterized by the above-mentioned. 5. The moving body noise measuring apparatus according to claim 1 , wherein the imaging means is a line sensor camera whose main scanning direction is perpendicular to the moving direction of the moving body. The moving image noise measuring apparatus according to claim 1 , wherein the imaging unit is a slit camera in which a slit is arranged perpendicular to a moving direction of the moving body. The said noise is a vibration, The noise measuring device of the moving body of any one of Claims 1-6 characterized by the above-mentioned. The said noise is electromagnetic noise, The noise measuring apparatus of the moving body of any one of Claims 1-6 characterized by the above-mentioned. An imaging step of continuously imaging a train as a moving body passing through a predetermined point multiple times along the moving direction;
A noise measuring step for measuring noise generated by the moving body;
A detection step of detecting passage of a predetermined portion of the moving body ;
The noise distribution associated with the moving body image is processed by synchronizing the noise measured in the noise measuring step and the image of the moving body imaged in the imaging step based on the detection signal obtained in the detecting step. A method for measuring noise of a moving object, comprising: An imaging process for continuously imaging a train as a moving body a plurality of times along the moving direction;
A noise measurement process for measuring noise generated by the moving body;
Detection processing for detecting passage of a predetermined portion of the moving body;
The noise distribution related to the moving body image is processed by synchronizing the noise measured by the noise measurement process and the image of the moving body imaged by the imaging process based on the detection signal obtained by the detection process. A program for causing a computer to execute a calculation process for calculating a value . A recording medium recording a program of claim 10.

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