JP2928873B2 - Signal processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for extracting a component arriving from a predetermined position on the basis of a measured coherent wave, or an apparatus for separating a wave measured for each arrival position.

[0002]

2. Description of the Related Art Recently, there has been a strong demand for noise reduction, and the need for sound source search is extremely high. For example, it is expected that a device that simply measures the direction or position of arrival of a wave, such as a sound source search to find a noise source for a sound wave, or a search for a source of an illegal radio wave, or that only a wave from a specific position is detected. ing.

In order to effectively reduce the noise of a machine, it is necessary to search for a sound source, and to measure from which part of the machine the problematic sound wave originates. In the case of automatic monitoring of equipment, a method of measuring vibration generated from equipment, temperature of equipment, and the like has been adopted. Furthermore, voice input has begun to be used as an input means to electronic machines. However, even if input is performed normally in a quiet environment, voice recognition becomes difficult due to background noise in a noisy environment. Therefore, it is necessary to search for a noise source so that a comfortable input can be performed.

[0004]

Therefore, a number of sound source searching methods such as sound intensity, sound holography, and phased array have been proposed. However, acoustic holography and phased arrays require a large number of microphones, resulting in high prices and large equipment.
There are problems such as the time required for calculation. The sound intensity is measured by two microphones, so the apparatus is simple. However, in order to search for a sound source, it is necessary to measure the sound intensity at a number of points.

When sound is used as a medium for monitoring equipment, a wide range of sounds can be collected, but sounds measured by microphones include sounds radiated from many machines. The S / N ratio decreases, and it becomes difficult to determine what state the monitored machine is in.

[0006] In a voice input device, a close-talking microphone is used to reduce the effects of such noise because it is affected by ambient noise. However, it is necessary to carry such a special microphone. Poor.

[0007]

SUMMARY OF THE INVENTION In order to solve such a problem , the present invention provides a method for detecting a wave arriving from an arbitrary position.
At least two wave collecting circuits to be detected and these waves
Provided for each collection circuit, the output signal of the wave collection circuit
To analyze the signal in each frequency band, or each frequency
Time-level change of signal in band as signal component
Frequency analysis circuit to output each and each frequency analysis circuit
For each frequency band signal component analyzed in
Calculate correlation between signal components for each signal component in several bands
And when the correlation value of both signal components exceeds the set value.
Detect the differences between the frequency bands and use them as delay times for each frequency band.
And a correlation calculation circuit that outputs
Of the signal components of each frequency band analyzed in the
The delay time output from the arithmetic circuit
For the signal components of the frequency band included in the box,
By extracting the signal components of
The wave component arriving from a specific position corresponding to the
It is designed to output every several bands.

Each frequency analyzed by each frequency analysis circuit is
Of the signal components in the wavenumber band, the
Frequency whose delayed time falls within the specified delay time range
Extract the signal components of the band signal components
And add the values to support the set delay time range
To output the wave component arriving from a specific position
It was done.

Further , a wave arriving from an arbitrary position is detected.
At least two wave collection circuits,
It is provided for each circuit and separates the output signal of the wave collection circuit.
Analyze signals in each frequency band or each frequency band
Time change of the signal at
The frequency analysis circuits that output the signals and the frequency analysis circuits
For each of the analyzed signal components in each frequency band,
For each signal component in the range, calculate the correlation between those signal components,
Time difference between both signal components whose correlation value exceeds the set value
For each frequency band
And a correlation calculation circuit for output.
Of the signal components of each analyzed frequency band, the correlation calculation
The delay time output from the road
For signal components in the frequency band included in any of them,
By extracting each signal component,
Waves arriving from multiple positions corresponding to the set delay time range
Dynamic components are output for each frequency band.
is there.

Further , each frequency analyzed by each frequency analysis circuit is used.
Of the signal components in the wavenumber band, the
Delay time is included in one of multiple set delay time ranges
Signal components of the frequency band
By taking out the minutes and adding them, the multiple settings
Wave formations coming from multiple locations corresponding to the delay time range
The minute is output.

[0011]

[Operation] Therefore, the wave detected by each wave collection circuit
Corresponds to each frequency band in the corresponding frequency analysis circuit.
Signal, or the temporal of the signal in each frequency band
The level changes are output as signal components, respectively, and
In the calculation circuit, each frequency analyzed by each frequency analysis circuit
Regarding signal components in several bands, signal components in each frequency band
And the signal whose correlation exceeds the set value.
No. component time difference is detected and each frequency band
Is output every time. And analyzed by each frequency analysis circuit.
Of the signal components of each frequency band
The output delay time is within the specified delay time range.
Signal components of each frequency band
Is retrieved and the specific delay time range
Wave components arriving from the position are output for each frequency band.
It is.

Each frequency analysis circuit analyzes each frequency.
Of the signal components in the wavenumber band, the
Frequency whose delayed time falls within the specified delay time range
Extract each signal component from the band signal component
Is added and specified according to the set delay time range
The wave component arriving from the position is output.

The wave detected by each wave collection circuit
Corresponds to each frequency band in the corresponding frequency analysis circuit.
Signal, or the temporal of the signal in each frequency band
The level changes are output as signal components, respectively, and
In the calculation circuit, each frequency analyzed by each frequency analysis circuit
Regarding signal components in several bands, signal components in each frequency band
And the signal whose correlation exceeds the set value.
No. component time difference is detected and each frequency band
Is output every time. And analyzed by each frequency analysis circuit.
Of the signal components of each frequency band
The output delay time is one of multiple set delay time ranges.
For each signal component of the frequency band included in
Signal components are extracted, and the multiple set delay time ranges
Wave components arriving from multiple positions corresponding to the
Output every few bands.

Each frequency analyzed by each frequency analysis circuit is
Of the signal components in the wavenumber band, the
Delay time is included in one of multiple set delay time ranges
Signal components of the frequency band
Minutes are extracted and added, and the multiple set delay times
Wave components arriving from multiple positions corresponding to the range are output
Is done.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the first invention. Sounds collected by microphones 1a and 1b (wave collection circuits) are supplied to frequency analysis circuits 2a and 2b, and the collected sounds are divided into a plurality of frequency bands. Frequency analysis for calculating the time change of the level for each of a plurality of frequency bands.

The frequency-analyzed signal (signal component) is supplied to a correlation calculation circuit 3 and an arithmetic circuit 5, where the cross-correlation between the outputs of the frequency analysis circuits 2a and 2b is calculated for each frequency band. Then, based on the lower limit value and the upper limit value of the delay time set by the delay time setting circuit 4, the arithmetic circuit 5 outputs a time-change waveform of the level of the frequency band that is the delay time falling within the range of the set delay time. You.

FIG. 2 shows the result of applying the present invention when there are two sound sources. The symbol "a" is the signal component of the sound source S1, the horizontal axis is time, the vertical axis is frequency, and the vertical axis is frequency. Above the axis shows high frequency components. The symbol "b" indicates a signal component of the sound source S2 located at a position different from S1.

Normally, if the sound source is different, the frequency component is often different, so that the sound source S1 and the sound source S2 have signals in different frequency bands. In order to easily understand the change in time, it is assumed that the sound source S1 is stationary but has a slight level fluctuation at first, and the sound source S2 is a sound source which generates a periodic noise such as a striking sound. And

The symbol "c" is a signal obtained as a result of analyzing a signal obtained when measurement is performed by the microphone 1a by the frequency analysis circuit 2a, and the symbol "d" is a signal obtained when measurement is performed by the microphone 1b. To the frequency analysis circuit 2b
It is obtained as a result of the analysis in.

As can be seen from this figure, the symbol "C"
Since the signal of “d” is mixed with both signals of the sound sources S1 and S2, the signal is different from the signal specific to each sound source, and the signal of only one of the sound sources cannot be separated. Comparing this figure for each frequency band, the signal of the symbol "c" indicates that the signal of the sound source S2 is detected later than the signal of the sound source S1 because the sound source S1 is closer to the microphone than the sound source S2. It can be seen that the signal of the symbol "d" is reversed.

Further, this delay time has the same value for the same sound source regardless of the frequency. Therefore, if the correlation of the signal waveforms of the symbols “c” and “d” is calculated for each frequency using the correlation calculation circuit 3 and the time (lag time) in which the correlation coefficient exceeds the set value is calculated, about what it is the same
Means that the signal components in the frequency band
Will output a value close to.

Therefore, if values close to the delay time (set delay time range) set by the delay time setting circuit 4 are grouped, if the set time corresponds to the sound source S1, the output of the arithmetic circuit 5 becomes a symbol. "E". Further, when a time delay corresponding to the sound source S2 is set, an output of the symbol “F” is obtained.

This output is obtained, for example, as follows, depending on the configuration of the arithmetic circuit 5. (A) By extracting the time change of the level of the frequency band corresponding to the set delay time, the time change of the level of only the wave component arriving from a specific position can be obtained. (B) By adding detection waveforms in a frequency band corresponding to the set delay time, a waveform of a wave arriving from a specific position can be obtained. (C) By extracting the time change of the level of the frequency band corresponding to each of the plurality of set delay times, the time change of the level is obtained for each of the wave components arriving from the set positions. . (D) By adding detection waveforms for each frequency band corresponding to a plurality of set delay times, a waveform of a wave arriving from a plurality of set positions can be obtained.

[0024]

As described above, according to the present invention, the waves collected by a plurality of microphones are subjected to frequency analysis, and those having the same correlation of the analysis results are extracted. Can output the time change of the level for each frequency band of the wave arriving from, the second embodiment can output the signal of the time waveform in the first embodiment, and the third embodiment corresponds to the one corresponding to a plurality of arrival positions in the first embodiment. According to the fourth aspect, it is possible to output a signal corresponding to a plurality of arrival positions according to the second aspect, and it is possible to extract a signal of a specific wave source even in an environment where many wave sources exist. Have.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing a state in which two wave sources are analyzed.

[Explanation of symbols]

 Reference Signs List 1 microphone 2 frequency analysis circuit 3 correlation calculation circuit 4 delay time setting circuit 5 arithmetic circuit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01H 3/00 G01H 3/08 G01S 3/802 G01S 7/288

Claims (4)

(57) [Claims] 1. Extraction of a wave component arriving from a predetermined position
In a signal processing device to be separated, at least two of which detect a wave coming from an arbitrary position
Wave collection circuits and the wave collection circuits provided for each of these wave collection circuits.
Analysis of the output signal of each frequency band,
Indicates the temporal level change of the signal in each frequency band.
Frequency analysis circuit that outputs each as a component, and signal components of each frequency band analyzed by each frequency analysis circuit
For each signal component in each frequency band.
Calculate the correlation for one minute and the correlation value exceeds the set value
Time difference between the two signal components
Calculation circuit that outputs for each frequency band, and the signal components of each frequency band analyzed by each frequency analysis circuit
Of the delay time output from the correlation calculation circuit,
For the signal components in the frequency band included in the set delay time range,
By extracting each signal component,
Wave arriving from a specific position corresponding to the set delay time range
A wave extraction circuit that outputs a dynamic component for each frequency band.
Signal processing apparatus, characterized in that it comprises. 2. The signal processing device according to claim 1, wherein a signal component of each frequency band analyzed by each frequency analysis circuit instead of the wave extraction circuit.
Of the delay time output from the correlation calculation circuit,
For the signal components in the frequency band included in the set delay time range,
To extract and add each signal component
From the specific position corresponding to the set delay time range
A signal processing device comprising: a detection waveform adding circuit that outputs an incoming wave component . 3. Extraction of a wave component arriving from a predetermined position.
In a signal processing device to be separated, at least two of which detect a wave coming from an arbitrary position
Wave collection circuits and the wave collection circuits provided for each of these wave collection circuits.
Analysis of the output signal of each frequency band,
Indicates the temporal level change of the signal in each frequency band.
Frequency analysis circuit that outputs each as a component, and signal components of each frequency band analyzed by each frequency analysis circuit
For each signal component in each frequency band.
Calculate the correlation for one minute and the correlation value exceeds the set value
Time difference between the two signal components
Calculation circuit that outputs for each frequency band, and the signal components of each frequency band analyzed by each frequency analysis circuit
Of the delay times output from the correlation calculation circuit,
Signals in frequency bands included in any of the set delay time ranges
Extracting each signal component for the signal component
More than one corresponding to the plurality of set delay time ranges
Outputs the wave component arriving from the position for each frequency band
Signal processing apparatus characterized by comprising a wave extraction circuit that. 4. The signal processing device according to claim 3, wherein the signal component of each frequency band analyzed by each frequency analysis circuit instead of the wave extraction circuit.
Of the delay times output from the correlation calculation circuit,
Signals in frequency bands included in any of the set delay time ranges
For signal components, extract and add each signal component
To support these multiple delay time ranges
Waves that output wave components arriving from multiple positions
A signal processing device comprising a shape adding circuit .