JP2588014B2 - Sound source coordinate measuring device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for measuring a coordinate position of a sound source of a measurement object. The apparatus of the present invention is used as input means for measuring the movement of an animal or inputting data or control signals from a three-dimensional coordinate position to an information processing apparatus.

〔Overview〕

The present invention relates to an apparatus for measuring a three-dimensional coordinate position of a sound source, comprising: outputting a sound wave having a predetermined pattern of temporal change in power spectrum to the sound source; and calculating the three-dimensional coordinate position of the sound source from the temporal change in power spectrum of the sound wave. Thus, the sound source of the object to be measured and the measurement device can be spatially separated from each other to improve noise resistance during measurement.

[Conventional technology]

Conventionally, in a measuring device of a three-dimensional coordinate position, an object to be measured and a measuring device are connected by some line.

[Problems to be solved by the invention]

For this reason, it is necessary to connect the measuring object and the measuring device with some kind of line, so that there is a problem that the measuring object is limited and the direction of movement of the measurable object is also limited.

Also, since the coordinate position is estimated based on the time at which the measured value becomes “0”, the measured value becomes indefinite if noise is mixed in, and accurate There was a problem that the coordinate position could not be measured.

The present invention solves the above-mentioned conventional disadvantages, and connects a sound source and a measuring device by a line by calculating a coordinate position from a time change of a power spectrum of a sound wave from a sound source received on the measuring device side. It is another object of the present invention to provide a sound source coordinate measuring device that can improve noise resistance during measurement without any noise.

[Means for solving the problem]

A plurality of sound sources each outputting a sound wave according to a predetermined pattern of a time change of the power spectrum, at least four microphones, a means for detecting a time change of each power spectrum of the sound wave received by the microphone, Means for calculating the three-dimensional coordinate position of the sound source on the basis of the time-varying pattern of the power spectrum detected by the means.

It is to be noted that a predetermined pattern of a temporal change of the power spectrum of the sound source can be set in the calculating means in advance. Further, the sound source includes a unit that repeatedly outputs a sound wave according to the predetermined pattern, and the calculation unit includes a three-dimensional coordinate position of the sound source based on a time change pattern of a power spectrum extracted from a sound wave received by one microphone. May be included.

[Action]

Sound waves emitted from the sound source unit are received by a plurality of microphones arranged on XYZ coordinates. The sound wave received by the microphone is converted into a digital signal, and then a time-varying pattern of the power spectrum is extracted at a predetermined frequency by a spectrum analyzer. The coordinate position of the sound source is calculated from the coordinate position of the microphone and the time relationship of the extracted power spectrum, and the three-dimensional coordinate position of the sound source is obtained.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of an embodiment of a sound source coordinate measuring apparatus according to the present invention.

The measuring apparatus of the present embodiment includes a sound source unit 1 and a measurement analysis unit 2. When the switch SW is turned on, the sound source unit 1 is a device that outputs a sound having a predetermined pattern of power spectrum time change from the sound wave generator SR. The measurement analysis unit 2 receives a sound wave from the sound source unit 1 and four microphones Mo, Mx, My, and 4 functioning as input devices of the measurement analysis unit 2.
M / z, analog / digital converters A / Do, A / Dx, A / Dy, A / Dz which convert analog signals from microphones Mo, Mx, My, Mz into digital signals respectively RAMo, RAMx, RAMy, RAMz for temporarily storing digital signals converted by the devices A / Do to A / Dz, and a spectrum analyzer SPAo for extracting a spectrum of a predetermined frequency from a sound source signal stored in the RAMo to RAMz, SP
Ax, SPAy, SPAz and this spectrum analyzer SPAo ~
A numerical calculation unit NCL for calculating a three-dimensional coordinate position of the sound source from a pattern of a time change of the frequency spectrum of the four sound source signals extracted by SPAz.

 Next, the measurement principle of the measurement apparatus of this embodiment will be described.

The sound source unit 1 and the measurement analysis unit 2 have, as common data, a time change P _s (t) of a power spectrum of a sound wave having a frequency f ₀ [Hz]. In the following description, all power spectra other than the frequency f ₀ [Hz] are described as “0” for simplicity.

Time change P _s (t) of the power spectrum at this frequency f ₀
Is defined by the following equation (1) with respect to the sound pressure x (t).

If you take time continuously If we take time discretely It can be expressed as. In this embodiment, it is assumed that the sound source unit 1 emits a sound wave having a time-varying power spectrum as shown in FIG.

When the switch SW is pressed, the sound source unit 1 performs the operation shown in the time chart of FIG. 3 to emit a sound wave having a time change of the power spectrum of f ₀ [Hz] from the sound wave generator SR.

The microphones Mo to Mz of the measurement analysis unit 2
And converts it into an electrical signal.

Time series data input from this microphone is
_j (t), where j = O, X, Y, Z, the analog-to-digital converters A / Do to A / Dz: Is converted to discrete time-series data.

The data converted into discrete time-series data by the A / D converter is expressed by the spectrum analyzer SPAo according to the equation (2).
The power spectrum is determined by ~ SPaz.

As described above, the power spectrum P _j for the time-series data W _j (t) input from the four microphones Mo to Mz
(F, t ₀ + nΔt) is obtained.

A calculation procedure for calculating the three-dimensional coordinates of the sound source unit 1 by the numerical calculation unit NCL from the four pairs of power spectra will be described.

The relative positions of the four microphones are shown in FIG.
Assuming that it is arranged at the Z-coordinate position, between the power spectrum of the f ₀ [Hz] component generated from the sound source unit 1 as shown in the time chart of FIG. 5 and the output of the spectrum analyzer SPA corresponding to each microphone. Assume that a time relationship has occurred.

 First, symbols such as various variables are defined as follows.

r _j : distance between sound wave generator SR and microphone M _j j =
O, X, Y, Z τ _ko : time until sound wave reaching microphone Mk reaches Mo k = X, Y, Z coordinates of microphone Mo (0,0,0) Mx (a, 0,0) My (0, b, 0) Mz (0,0, c) Sound source coordinates SR (X _s , Y _s , ZR _s ) First, τ _ko (k = X, Y, Z) is obtained.

Next, a time change P _j (f, t _{0) of} four pairs of power spectra obtained as outputs of each of the spectrum analyzers SPAo to SPAz.
+ NΔt) and the time change P _s (f, t ₀ + nΔt) of the power spectrum that is held as common data are calculated. That is, C _js (m _j ) = ΣP _j (f, t ₀ + nΔt) P _s (f, t ₀ + (n−
_{m j) Δt) ...... (5} ) where, C _js (m _j) τ Writing m _j that maximizes the m _jmax the _{ko = (m kmax -m 0max)} Δt k = X, Y, as Z Desired.

The distance between each microphone and the sound source can be expressed by the respective coordinates as follows.

By transforming equation (6), Becomes By the way, r _k = r _o −v _c τ _ko (8) where k = X, Y, Z, and v _c = sound velocity, so that equation (7) can be further modified as follows.

In the above equation, there are three unknowns, X _s , Y _s , and Z _{s. If} the equation (9) is calculated by a numerical calculation method, a solution can be obtained and the three-dimensional coordinate position of the sound source can be obtained.

As a result, there are a plurality of sound sources SR _i (i = 0, 1,..., N), each of which has its own frequency f _i [Hz] and its time change of its own power spectrum P (f _i , t), the time change of the power spectrum for each unique frequency can be extracted and the coordinate position for each frequency can be obtained by calculation, so that the position and shape of an arbitrary object, and further, It is possible to estimate the movement.

Further, assuming that the time change P _s (f, t) of the power spectrum to be held as the common data is calculated from data W ₀ (t) measured by the microphone Mo instead of the predetermined data, Can be estimated by calculation.

That is, a sound wave having the same time change of the power spectrum is repeatedly output from the sound source unit 1, and the pattern of the time change of the repeated power spectrum is extracted from the data measured by the microphone Mo. The three-dimensional coordinate position of the sound source unit 1 is calculated by the numerical calculation unit NCL based on the obtained pattern.

〔The invention's effect〕

Since the present invention is configured as described above, the three-dimensional coordinate position of the sound source of the measurement target can be obtained while the measurement target and the measurement device are spatially separated. Furthermore, since the three-dimensional coordinate position of the measurement object is obtained from the time change of the power spectrum of the sound source, the influence of the mixed noise can be reduced and the sound source coordinate position measuring method with improved noise immunity can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention. FIG. 2 shows an example of a temporal change of the power spectrum. FIG. 3 is a time chart showing the operation of the tone generator of the embodiment. FIG. 4 is a diagram showing coordinate positions of a microphone. FIG. 5 is a diagram showing the correlation between the component intensity of f ₀ [Hz] generated from the sound source unit and the output of each spectrum alanizer. 1. Sound source unit 2. Measurement and analysis unit, SW switch, SR sound wave generator, Mo to Mz microphone, A / Do to A / Dz analog to digital converter, SPAo to SPAz spectrum analyzer, NCL numerical value Calculation part.

Claims (1)

(57) [Claims] 1. A plurality of sound sources each outputting a sound wave according to a predetermined pattern of a time change of a unique power spectrum, at least four microphones, and detecting a time change of each power spectrum of a sound wave received by the microphone. Means for calculating a three-dimensional coordinate position of the sound source based on a time-varying pattern of the power spectrum detected by the detecting means. A sound source coordinate measuring device having a pattern set.