JP2001141438A - Device for measuring thickness of bottom mud - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of the necessity of two types of ultrasonic oscillators in a measuring device to use ultrasonic waves of two frequencies or more and the depth difference of detected ultrasonic waves and the problem of the necessity for previously setting of theoretical water depth and a complicated and expensive system in a measuring device to measure the thickness of mud from the difference between the depth of a tank or the like with previously known water depth and a measured depth. SOLUTION: An oscillator 9 to generate low-frequency short pulses (1 wavelength-a few wavelengths) is connected to a control device 8 composed of a CPU, and an ultrasonic transmitting oscillator 10 is connected to the oscillator 9. In addition, an ultrasonic receiving oscillator 11 to receive the reflected echoes of the ultrasonic waves projected from the ultrasonic transmitting oscillator 10 is connected to an amplifier 12, and the output of the amplifier 12 is connected to an A/D converter 13. The output of the A/D converter 13 is inputted to the low-level gate 8a and the high-level gate 8b of the control device 8, and the outputs of the low-level gate 8a and the high-level gate 8b are connected to a display device 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring bottom sludge thickness by using a short pulse (one wavelength to several wavelengths) to easily recognize a sludge layer surface.

[0002]

2. Description of the Related Art Conventionally, as an apparatus for measuring the thickness of bottom mud on the seabed or lake bottom, as shown in FIG. 3, an ultrasonic transmitter 2 connected to a transmitter / receiver 1 is installed in the sea or underwater 3, When ultrasonic waves are emitted from the ultrasonic transmitter 2 toward the sea floor or the lake bottom 4, reflected waves from the sea bottom or the lake bottom 4 and reflected waves from the surface of the sludge 5 deposited on the sea bottom or the lake bottom 4 are generated. When the sludge 5 has a small thickness but is received by the ultrasonic receiver 6, if a pulse having a long wavelength is used, a pulse of a reflected wave from the surface of the sludge 5 and a pulse of a reflected wave from the sea floor or the lake bottom 4 are used. When the cathode ray tube 7 connected to the transmitter / receiver 1 displays, the reflected waves of the sea bottom or the lake bottom 4 and the sludge 5 are united to be indistinguishable.

[0003]

Therefore, in a conventional bottom sediment thickness measuring apparatus, a measuring apparatus utilizing ultrasonic waves of two or more frequencies and utilizing the difference in the depth of the detected ultrasonic waves, or a water depth which can be determined in advance. There is a device that measures the mud thickness based on the difference between the depth of the tank or the like and the measured depth. However, a measuring device that uses two frequencies requires two types of ultrasonic transducers, In a measuring device using the difference, it is necessary to set a theoretical water depth in advance, and there is a problem that the system is complicated and expensive.

[0004]

SUMMARY OF THE INVENTION The present invention provides a low-frequency oscillator for generating short pulses (one wavelength to several wavelengths), irradiates an ultrasonic pulse into water with short pulses from the oscillator, and irradiates the water with water. Ultrasonic transducer for receiving the reflected wave of the ultrasonic pulse, an amplifier for amplifying the echo signal converted by the ultrasonic transducer, and an A / D converter for converting the output of the amplifier to a digital echo signal A low-level gate function having a low threshold for passing a predetermined low-level signal among digital echo signals converted by the A / D converter, and passing a high-level signal having a predetermined threshold or more. And a display device for displaying the low-level signal and the high-level signal on the same screen, and irradiates short-pulse ultrasonic waves into the water from the ultrasonic vibrator. Thus, the reflected echo from the surface of the bottom mud and the reflected echo from the water bottom below the bottom mud do not interfere with each other, and the control device is provided with a multiplication function and is input to the control device. The level of the digital echo signal may be increased to facilitate display on the display device.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, low-frequency ultrasonic waves are used to allow the sludge to pass well,
Also, by using short pulses (one wavelength to several wavelengths), even in a thin sludge layer, the reflection echo reflected on the surface of the sludge layer and the reflection echo reflected on the sea floor or lake bottom can be separated well without interference. The high reflection echo signal reflected on the sea floor or lake bottom and the low reflection echo signal reflected on the sludge pass through the low level gate and the high level gate attached to the control device, respectively, and are reliably displayed on the display device. Can be.

[0006]

FIG. 1 is a block diagram of a bottom mud thickness measuring apparatus according to an embodiment of the present invention.
An oscillator 9 for generating a short pulse (one wavelength to several wavelengths) is connected, an ultrasonic transmission oscillator 10 is connected to the oscillator 9, and a reflection echo of an ultrasonic wave emitted from the ultrasonic transmission oscillator 10 Is connected to an amplifier 12, and the output of the amplifier 12 is an A / D converter 13
The output of the A / D converter 13 is input to the low-level gate 8a and the high-level gate 8b of the control device 8, and the outputs of the low-level gate 8a and the high-level gate 8b are connected to the display device 14. .

[0007] In the bottom mud thickness measuring apparatus of the present embodiment configured as described above, when the oscillation output from the oscillator 9 is applied to the ultrasonic transmission oscillator 10 by the signal from the control device 8, the ultrasonic transmission oscillator 10 Irradiates ultrasonic waves into the sea or underwater, so that a high-level reflected echo of ultrasonic waves is input to the ultrasonic receiving vibrator 11 from the sea floor or the bottom of the lake. The ultrasonic wave is reflected on the surface of the ultrasonic wave, and a low-level reflected echo is input to the ultrasonic receiving vibrator 11, converted into a high-level reflected echo signal and a low-level reflected echo signal, respectively, and amplified by the amplifier 12,
The signal is converted into a low-level digital echo signal and a high-level digital echo signal by the A / D converter 13, and is input to the low-level gate 8a and the high-level gate 8b of the control device 8,
Each of the low-level digital echo signals passes through the low-level gate 8a, and the high-level digital echo signal passes through the high-level gate 8b.
Is displayed with.

Here, in the bottom mud thickness measuring apparatus of this embodiment,
Since the oscillator 9 generates short pulses (one wavelength to several wavelengths), the reflected echo reflected on the sludge surface and the reflected echo reflected on the sea bottom or lake bottom are sure even if the bottom mud thickness is small. The sludge is measurably displayed on the display device 14. However, the thickness of the measurable sludge is determined by the number of wavelengths of the ultrasonic waves to be irradiated. It is possible to distinguish a reflected echo reflected from a sea floor or a lake bottom from a reflected echo.

When displaying on the display device 14, it is possible to display the seabed or lake bottom and the sludge in different colors. However, in the case of displaying these different colors, the reflection reflected on the surface of the sludge is performed. When the echo is low, as shown in FIG. 2, a multiplier 8c is provided before the low-level gate 8a of the control device 8.
May be provided.

In the above embodiment, the ultrasonic transmitting oscillator 10 and the ultrasonic receiving oscillator 11 are provided separately, but one ultrasonic oscillator may be used.

[0011]

As described above, in the bottom mud thickness measuring apparatus of the present invention, the oscillator generates short pulses (one wavelength to several wavelengths). The reflected echo reflected at the bottom of the sea and the reflected echo reflected at the bottom of the sea or lake are not interfered with each other so that they can be separated well. There is an advantage that the display can be reliably displayed on the display device by passing through the high level gate and the low level gate respectively provided in the above.

[Brief description of the drawings]

FIG. 1 is a block diagram of a bottom mud thickness measuring apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a bottom mud thickness measuring apparatus according to another embodiment of the present invention.

FIG. 3 is an explanatory diagram of a conventional bottom mud thickness measuring device.

[Explanation of symbols]

 Reference Signs List 8 control device 9 oscillator 10 ultrasonic transmitting oscillator 11 ultrasonic receiving oscillator 12 amplifier 13 A / D converter 14 display device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Keiichi Sato, inventor Ryobi Co., Ltd. 3-1-1, Kanda, Chiyoda-ku, Tokyo (72) Tatsuya Wada 762, Mezaki-cho, Fuchu-shi, Hiroshima In-house F term (reference) 2F068 AA28 BB14 CC05 DD04 FF03 FF12 FF14 FF25 KK13 KK14 QQ01 QQ03 QQ05 5J083 AA02 AB07 AB20 AC28 AD30 AE06 BA01 BE19 BE29 CA01 CA02

Claims (2)

[Claims] 1. A low-frequency oscillator for generating a short pulse (one wavelength to several wavelengths), an ultrasonic pulse is irradiated into water by a short pulse from the oscillator, and a reflected wave of the ultrasonic pulse irradiated into the water is generated. A receiving ultrasonic transducer, an amplifier for amplifying an echo signal converted by the ultrasonic transducer, an A / D converter for converting an output of the amplifier into a digital echo signal, and an A / D converter. A control having a low level gating function having a low threshold value that passes a predetermined low level signal in the converted digital echo signal and a high level gating function passing a high level signal that is equal to or more than the predetermined low threshold value Device, and a display device that displays the low-level signal and the high-level signal on the same screen, and irradiates short-pulse ultrasonic waves into the water from the ultrasonic vibrator, so that A bottom sediment thickness measuring device characterized in that reflected echoes and reflected echoes from the water bottom below the sediment do not interfere with each other. 2. The bottom mud according to claim 1, wherein a multiplying function is provided in the control device, and the level of a digital echo signal input to the control device is increased to facilitate display on the display device. Thickness measuring device.