JPS6085381A - Sludge surveyor - Google Patents

Abstract

PURPOSE:To minimize errors in depth to the surface of sludge and the bottom of water by attaching a delay circuit to a system of receiving sound wave. CONSTITUTION:Variable delay circuits 21 and 22 added are connected to amplifiers 15 and 16 and then, to a record amplifier 17 through a variable switch. Two different frequencies fH and fL pass through the delay circuits 21 and 22 to delay the received wave signal for the correction of the time delay in the receiving system, which enables a recording with limited depth errors. The delay circuit 21 or 22 are given a preset delay value, which is adjusted with a rigid body placed under water and as a signal reflected from the rigid body will not vary with the frequency, it indicates the same depth. Thus, errors in the electric system can be minimized by adjusting and calibrating the delay circuits 21 and 22 so that depth values may appear at the respective fixed position on the record.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a sludge probe that measures the layer thickness of private sludge on the bottom of an ocean.

[Prior art]

Below are 1. A conventional sludge probe will be explained based on drawings, and its drawbacks will be discussed.

FIG. 1 is a block diagram of a conventional sludge probe 1. 1 is a motor, 2 is a recording pen, 3 is a recording paper, 4 is a synchronization pulse generator, 5 is a transmission timing circuit, 6 and 7 are oscillator, 8 is a synthesis circuit, 9 is a transmitter 2, 10 is a transmitter/receiver switch,
11 is a transducer, 12 is a receiver, 13 and 14 are filters, 15 and 16 are amplifiers, 17 is a recording amplifier, 18 is underwater, 19 is the sludge surface, and 20 is the bottom surface of the water. In addition, H is the depth at 19 degrees on the sludge surface, and L is the water bottom surface 20 below the sludge.
The dotted lines from the transducer 11 indicate two sound waves with different frequencies.

Conventional sludge probes have fallen into disrepair as described above.

Next, I will explain its function, but before that, I will explain the basic principle of this sludge probe.

That is, when two-frequency sound waves are simultaneously sent to a sound field medium,
A parametric effect is created in which a sound wave interaction is caused by the nonlinear characteristics of the sound field, and a frequency component of the sum and difference of the two frequencies is generated, and in this case, the frequency component of the difference becomes a sound wave with extremely sharp directivity. It's where I used it. That is, an ultrasonic signal with a relatively high frequency is reflected from the sludge surface 19 in the drawing, the propagation time of the ultrasonic signal and the depth to the sludge surface 19 are measured, and the signal passes through the sludge layer. An ultrasonic signal with a relatively low frequency is reflected on the water bottom surface 20 in the above drawing, and the depth to the water bottom is measured from the propagation time, and the thickness of the Shihedro layer is determined based on the measurement results of both cylinder wave numbers + fL. is measured.

The following will explain based on the drawings.

When the belt 2 moves over the recording paper 3 by the morph 1 and the recording pen 2 reaches the recording start point, the synchronization pulse generator 4 generates a pulse. The pulse is sent to the transmission timing circuit 5
The transmission timing is created at 0. According to the transmission timing, the oscillator 6 transmits a pulse signal with a relatively high frequency k (for example, 100 KH25), and the oscillator 7 transmits a pulse signal with a frequency h that is lower than h (for example, 90 KH2).

The frequencies RI and fL are combined in a combining circuit 8, amplified to a constant level in a transmitter 9, and then applied to a transmitter/receiver 11.

The electrical signal is converted into an ultrasonic signal by the transducer 11 and sent to the underwater 1
It will be launched on 8.

The sound waves emitted into the water 18 are reflected by the sludge surface 19, and an ultrasonic signal having a frequency difference due to the parametric effect is generated and reflected at the bottom surface 2 degrees of the water. Both reflected sound waves are received at transmission/reception sg:+1i.

The received signal is passed through a transmitter/receiver switch 10, amplified to a constant level by a receiver 12, and a filter 13 passes only a signal of 5(5), and a filter 14 passes only a signal of /L.

Both signals are amplified to a constant level by amplifiers 15 and 16, and then added and amplified by a recording amplifier 17, and then added to the recording pen 2 and recorded on the recording paper 3.

Next, the state of recording to LTh3 will be described based on an example of recording by the conventional sludge probe shown in FIG.

The recording pen 2 moves while the ultrasonic waves in the water 18 are propagating, and the difference in the position of the recording pen 2 between the time of transmission and the time of reception is recorded on the recording paper 3 as the depth.

Therefore, since there is a difference of about 10 times between the frequencies fH and fr handled by the receiving system, the following drawback occurs.

That is, the frequencies jH, l! in the filters 13, 14, amplifiers 15, 16, and transducer 11. : A difference in delay time arises from a difference in frequency characteristics of fL, resulting in a depth error.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, the present invention aims to solve the conventional drawbacks by correcting the difference in delay time between fL and the same wave number.

[Structure of the invention]

The structure of the present invention is as follows.

Both amplifiers of the components in the conventional example are each provided with a variable delay circuit and connected to the recording amplifier.

〔Example〕

Hereinafter, two embodiments of the present invention characterized by the above-mentioned purpose and configuration will be explained based on the drawings, and the effects thereof will be described. Incidentally, for components that are the same as those in the conventional example, the same reference numerals as those in the conventional example are used.

FIG. 3 is a block configuration diagram of a sludge probe according to the J embodiment of the present invention, in which 1 is a morph 12, a recording pen, 3 is a recording paper, 4 is a synchronization pulse generator, 5 is a transmission timing circuit, 6 and 7 are oscillators, 8 is a synthesis circuit, 9 is a transmitter, 10
11 is a transmitter/receiver, 12 is a receiver, 13.
14 is a filter, is and ie are amplifiers, 17 is a recording amplifier, 18 is underwater, 19 is the sludge surface, 20 is the water bottom surface, H is the depth to the sludge surface 19, and L is the depth to the water bottom surface 20. , the dotted lines indicate two sound waves with different frequencies.

The above is the same as the conventional example, and the configuration of the variable delay circuit added according to the present invention will be described below.

Reference numerals 21 and 22 denote variable delay circuits added according to the present invention, which are connected to amplifiers 15 and 16 and then connected to the recording amplifier 17 via a variable switch.

The first embodiment of the present invention is configured as described above, and its operation is similar to the conventional one, but 5. two different frequencies fiI+,
h- is passed through delay circuits 21 and 22, and by delaying the received signal, the time delay of the receiving system is corrected, and recording with a slight depth error can be performed.

Note 6. The delay circuit 21 or 22 has a preset delay amount, and this delay amount can be adjusted by placing a rigid body in the water, and since the signals reflected from this body do not differ depending on the frequency, It will be shown. This minimizes stain system errors by adjusting and calibrating the delay circuits 21, 22 so that they appear at the same location on the record.

Next, the amount of delay will be described based on the received signal shown in FIG. In FIG. 4, the input signal to the delay circuit 21 is A, and the input signal to the delay circuit 22- is B.

As shown in the figure, in a recording amplifier that is set to record at a constant level, high frequencies are sung early. Even if the rising wave number is the same, the wavelengths are different, so fL is delayed and dies out. .

Therefore, I21vk n from the time of transmission to the time of recording
If the fiI wave is TH% and the fLO wave is TL, then THT
It can be seen that a certain amount of error occurs. When this error occurs, the frequency fx,
It delays the In addition, if the depth differs depending on the frequency 9, it may be adjusted by the delay circuit 21 that inputs fI().

Note 1: In this case, since recording can only be delayed, the absolute values H and L will have a fixed error equal to this delay time. This can be done by reading the scale or by shifting the scale when reading.

Next, it is also possible to apply the following delay circuit instead of the delay circuits 21 and 22 according to the first embodiment.
This will be explained as a second embodiment. 71), based on Figure 5.

Fig. 5 shows the delay circuit configuration showing the second example.
3 is an analog-digital converter, 24, 25° 26.2
7 is a shift register; 28, 29, 30; 31 are switches that operate in conjunction with each other; and 32 is a digital-to-analog converter.

If this circuit is replaced with the delay circuits 21 and 22 of the first embodiment, the analog-to-digital converter 23 converts the signal into 4 bits in the case of this figure and inputs it to the shift registers 24-27.

Each bit of the shift registers 24 to 27 is outputted and connected to the switches 28 to 31, and the shift length of each bit is set to no bits. If the gap between shift pulses is T seconds, the delay time at any n-th bit is naturally T seconds.

In this way, by taking the n-th bit output from the first stage of the shift registers 24 to 27, it is possible to delay the processing by nTT seconds.

The delayed signal is again converted into an analog signal by the digital-to-analog converter 32.

In this way, in the second embodiment, the delay correction of the received signal can be performed in the same manner as in the case where the first fruit is 0. A delay circuit was added to @Makoto's receiving system in the sludge probe, which measures the thickness of the sludge layer by transmitting two sound waves to the bottom of the water and receiving the reflected sound waves from the sludge surface and the bottom surface. It can be effective.

It measures the depth to the sludge surface and the depth at the bottom n1, and determines the -\1・oQ thickness by the difference between the two, so in conventional probes, the two types of sound waves are The present invention solves the drawback that a difference in delay time occurs due to a difference in characteristics and causes an error in the depth, and since the difference in delay time can be adjusted by a delay circuit added to the receiving system, the depth error between the sludge surface and the water bottom can be reduced. This has the effect of reducing

This allows accurate exploration of the sludge layer.

Thus, the present invention can be advantageously utilized in sludge exploration.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional sludge probe, FIG. 2 is a recording paper showing a conventional recording example, FIG. 3 is a block diagram of a sludge probe according to the first embodiment of the present invention, and FIG. 4 is a received signal diagram, and FIG. 5 is another delay circuit diagram showing the second embodiment. 1...Motor 2...Recording pen 3...Recording paper
4... Synchronous pulse generator 11... Transducer/receiver 18.
...Underwater 19...Sludge surface 20...Underwater surface Patent applicant Takashi Kanakura, Patent attorney representing Oki Electric Industry Co., Ltd.

Claims (1)

[Claims] 1 Oscillator that creates ultrasonic waves with frequency In and frequency f+
Equipped with an oscillator that creates ultrasonic waves with a frequency fL lower than y, the frequencies fH and 9 are combined and added to the transducer, and the transducer generates ultrasonic waves of the combined frequency fL and JL on the bottom of the water. The two ultrasonic waves reflected from the sludge surface and the water bottom are received by the transducer, and the received signals are separated by two filters and amplified by respective amplifiers. In a sludge probe that records the transmission and reception times of ultrasonic waves of ，! : A delay circuit is installed in one or both of the amplifiers that amplify the received ultrasonic waves of JL, and the amount of delay due to the difference in the frequency characteristics of frequency power (and fL) is compensated in advance by the delay circuit. Sludge probe.