JP2009171530A

JP2009171530A - Method for dividing ultrasonic analogue signal

Info

Publication number: JP2009171530A
Application number: JP2008028166A
Authority: JP
Inventors: Sadao Nakajo; 定男中城
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-01-10
Filing date: 2008-01-10
Publication date: 2009-07-30

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which a frequency spectrum does not change even if transferring it to a low frequency region when dividing an ultrasonic analogue signal to convert to an audio frequency. <P>SOLUTION: The method includes a process to carry out an analogue-to-digital conversion with a high speed clock from a point crossing zero of analogue to a point crossing the next zero when dividing the ultrasonic analogue signal, and a process which quickly connects a memorized wave while matching a polarity when connecting the memorized wave by an unit of 180° or multiple of 180° while reproducing any low speed clock. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

この発明は超音波アナログ信号の分周方法に関するものである。The present invention relates to a method for dividing an ultrasonic analog signal.

従来、超音波アナログ信号波形を忠実にリアルタイムで分周する方法が無かった。
従って超音波アナログ信号等を可聴音にして聞く事が難しかった。
例えば、２０ＫＨｚから１５０ＫＨｚまでの超音波を同時に聞くことが難しかった。Conventionally, there has been no method for accurately dividing an ultrasonic analog signal waveform in real time.
Therefore, it was difficult to hear an ultrasonic analog signal or the like as an audible sound.
For example, it was difficult to simultaneously listen to ultrasonic waves from 20 KHz to 150 KHz.

（イ）超音波アナログ信号を可聴音にして聞く時、超音波アナログ信号に対してビート信号を発生させた後、２つの信号を混合し、その後にフィルターなどを通さなければ聞くことが出来なかった。
（ロ）ビート信号に対して２０ＫＨｚ迄位で、聞くことが出来たとしても忠実な周波数スペクトラムにはならなかった。
本発明は、分周クロックによって分周比が変えられるため、読み出しの周波数を書き込み周波数の１０分の１に設定すれば、２０ＫＨｚから１５０ＫＨｚまでの音を、２ＫＨｚから１５ＫＨｚで聞くことができる超音波アナログ信号分周方法である。(B) When listening to an ultrasonic analog signal as an audible sound, after generating a beat signal for the ultrasonic analog signal, the two signals must be mixed and then passed through a filter, etc. It was.
(B) Even if it was possible to hear the beat signal up to 20 KHz, it did not become a faithful frequency spectrum.
In the present invention, since the frequency division ratio can be changed by the frequency-divided clock, if the read frequency is set to 1/10 of the write frequency, the sound from 20 KHz to 150 KHz can be heard from 2 KHz to 15 KHz. This is an analog signal dividing method.

超音波アナログ信号を分周する方法を述べる。
超音波信号をゼロから正の方向に横切る点から、ゼロから負の方向に横切る点迄のプラス側の信号を高速クロックでアナログ−デジタル変換し、メモリーに蓄える。
超音波アナログ信号を分周する比、例えば１０分の１にしたいのなら、この高速クロック周波数の１０分の１のクロックを使い、プラス側のデータをデジタル−アナログ変換し、出力する。
プラス側の信号を出力している間に、マイナス側の信号ゼロから負の方向に横切る点から、ゼロから正の方向に横切る点までを同様にアナログ−デジタル変換し、別のメモリーに蓄える。
プラス側の信号を出力し終わり次第、速やかにマイナス側の信号の分周をし、その後に続ける。
以後この作業を続ける。A method of dividing the ultrasonic analog signal will be described.
The signal on the plus side from the point where the ultrasonic signal crosses in the positive direction from zero to the point where it crosses in the negative direction from zero is converted from analog to digital with a high-speed clock and stored in the memory.
If the ratio for dividing the ultrasonic analog signal, for example, 1/10, is desired, a clock of 1/10 of this high-speed clock frequency is used, and the plus-side data is converted from digital to analog and output.
While outputting the positive signal, analog-digital conversion is similarly performed from the point that crosses the negative signal from zero to the negative direction to the point that crosses from zero to the positive direction, and is stored in another memory.
As soon as the positive signal is output, the negative signal is divided immediately and then continues.
This work is continued thereafter.

超音波アナログ信号のゼロを横切る点から、ゼロを横切る点まで、２分の１周期毎、又は１周期毎に、分周した信号の極性を合わせながら繋いで行く方法で信号を再生する。
この方法で再生すれば、特殊な場合を除き周波数スペクトラム、つまり超音波帯域を可聴周波数の帯域に移行できる。
またこの方法で信号再生させればリアルタイムで可聴音での再生が出来る。The signal is reproduced by a method in which the polarities of the divided signals are matched to each other at every half cycle or every cycle from a point crossing zero of the ultrasonic analog signal to a point crossing zero.
By reproducing in this way, the frequency spectrum, that is, the ultrasonic band can be shifted to the audible frequency band except in special cases.
If the signal is reproduced by this method, it is possible to reproduce the audible sound in real time.

超音波アナログ信号を分周するには、基準値つまり信号のゼロを正側に横切る点（３）より、負側に横切る点（４）迄、変換したい超音波アナログ信号の最大周波数の，数倍の書き込みクロックで、アナログ−デジタル変換をし、アドレスとデジタル値を記憶する。
次にこの書き込み周波数の数分の１の読み出しクロックで、（３）から（４）までのデータを、デジタル−アナログ変換し、（７）から（８）のように引き伸ばしスピーカーなどへ出力する。この数分の１がそのまま分周比となる。
（７）から（８）迄の間に、今度は負側に横切る点（５）から、正側に横切る点（６）迄、同様に別のメモリーに記憶する。（８）が終わり次第、（５）から（６）迄のデータを（９）から（１０）と続けて出力する。
この作業を繰り返す。To divide an ultrasonic analog signal, the number of the maximum frequency of the ultrasonic analog signal to be converted from the reference value, that is, the point that crosses zero of the signal to the positive side (3) to the point that crosses the negative side (4). Analog-to-digital conversion is performed with the double write clock, and the address and digital value are stored.
Next, the data from (3) to (4) is subjected to digital-analog conversion with a read clock of a fraction of the write frequency, and is output to a speaker or the like as shown in (7) to (8). This fraction is directly used as the frequency division ratio.
From (7) to (8), this time, the point (5) crossing to the negative side to the point (6) crossing to the positive side are similarly stored in another memory. As soon as (8) is finished, the data from (5) to (6) are output continuously from (9) to (10).
Repeat this process.

超音波アナログ信号の図である。It is a figure of an ultrasonic analog signal. 分周後のアナログ信号である。This is an analog signal after frequency division.

Explanation of symbols

（１）超音波アナログ信号である。
（２）信号ゼロレベルである。
（３）（４）（５）（６）アナログ信号がゼロレベルを横切る点である。
（７）（８）信号プラス側の出力波形である。
（９）（１０）信号マイナス側の出力波形である。(1) Ultrasonic analog signal.
(2) The signal is at zero level.
(3) (4) (5) (6) This is the point where the analog signal crosses the zero level.
(7) (8) Output waveform on the plus side of the signal.
(9) (10) The output waveform on the minus side of the signal.

Claims

When dividing the signal as shown in [Fig. 1] using the method of dividing the ultrasonic analog signal, the positive signal from (3) to (4) is analog-to-digital converted with a high-speed clock, and the stored waveform is stored. Digital-to-analog conversion is output as shown in (7) to (8) with a clock slower than the high-speed clock. During this time, the next negative direction signal is memorized in the same way for (5) to (6), and is divided so as to be connected as shown in (9) to (10).

Ultrasound by a reproduction method that connects the divided waveforms at zero while adjusting the polarity even when connecting the divided waveforms every 180 °, or when connecting at a multiple of 180 °, such as when connecting every 360 ° C. Analog signal division method.