JPH0253726B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device for scanning and measuring the layer thickness of adult organisms that grow on the basis of underwater rocks and structures.
It can also be used on flat or unevenly curved substrates.

An embodiment of the present invention shown in the accompanying drawings will be described. A scanning body 5 equipped with an ultrasonic signal transducer 4 is slidably provided on a guide 3 fixed to a frame 2 supported by a support leg 1. A waterproof drive box 6 containing driving devices such as an electric motor, a speed reducer, and a switch is fixed to the side of the body 2, and the electric motor and other driving devices inside can be controlled from above the water surface by a waterproof cable 7. It can also be operated by a scanning handle 8 provided on the outer wall of the drive box 6.

The waterproof drive box 6 has a drive shaft 9 driven by a built-in electric motor protruding from the box, and the drive shaft 9 transmits power to a drive sprocket 11 supported on one side of the frame 2 via an appropriate transmission mechanism 10. , drive sprocket 1
A sprocket 1 is provided on the other side of the frame 2 opposite to the sprocket 1.
2 and the chain 1 suspended from the drive sprocket 11
Both ends of the chain 13 are connected and fixed at the front and rear of the scanning body 5, and the scanning body 5 connected to the chain 13 slides along the guide 3 by rotation of the drive sprocket 11.

The transducer 4 is connected by a cable 21 to a measurement calculation device provided on the water surface.

FIG. 3 is an example of a block diagram schematically showing the above-mentioned measurement and calculation device, which has the same configuration as a depth sounder consisting of a transmitting section 16, a receiving section 17, a trap circuit 18, a calculating section 19, and a display section 20. An electrical signal from the transmitting section 16 that transmits a pulse signal modulated by
The ultrasonic pulse is converted into an ultrasonic pulse, radiated into the water, reflected by an adult creature in the water, received by the transducer 4, converted into an electrical signal, sent to the receiver 17, and amplified and detected.

The trap circuit 18 is for protecting the receiving section 17 from the strong transmission pulse signal of the transmitting section 16 and transmitting the received reflected signal to the receiving section 17 without loss.
The thickness of the adult organism is calculated as a digital value and displayed or recorded on the display unit 20.

To measure the adhesion state of underwater structures using the above device, as shown in Figure 4,
Crimp the support leg 1 on the This operation is carried out by underwater workers, but if the attached organisms are hard, only the supporting legs should be removed.Furthermore, the base A may be in a vertical position instead of horizontally, and the base A may be a steel fishing reef or a ship's hull. In such a case, a permanent magnet may be attached to the tip of the supporting leg 1 to attract it to the base.

In this state, a signal is sent from the transmitter 16 on the sea to the transducer 4, and the transducer 4 emits ultrasonic pulses at regular intervals, while the electric motor in the waterproof drive box 6 is rotated by the worker on the surface of the water or under the sea. The scanning body 5 connected to the chain 13 is moved along the guide 3, and the ultrasonic wave emitted from the transducer 4 receives the signal reflected by the adult organism, converts it into an electrical signal, and sends it to the receiving section. Send to 17th.

As shown in FIG. 5, this transmitted and received signal consists of constant periodic transmission pulses P ₁ , P ₂ . . . P _o and reflected signal pulses E ₁ ,
E ₂ ...E _o alternate, and the time t ₁ , t ₂ ...t _o between each transmitted signal pulse P and received signal pulse E is
is proportional to the distance l between the surface of
S ₁ , S ₂ ... Distance between transducer 4 and adult organism B for each S _o
Since l ₁ , l ₂ ...l _o can be calculated, and the distance l ₀ between the transducer 4 and the base A is known, the thickness l _t of the adult organism B can be calculated by l ₀ - l. information on the layer thickness of adult organisms at the scanning position.

In Figure 6, the vertical axis is the scanning distance for each period S ₁ , S ₂ ...S _o , and the measured value l by the transducer 4 and the thickness of the adult
lt is a diagram with _t as the horizontal axis.

The thickness of the adult organism B can be measured by the above calculation only when the base A is flat and the transducer 4
This is when the scanning by is parallel to the base plane A.

However, in reality, the distance between the transducer and the board A is l ₀
If it is difficult to understand, or if there are irregularities on the board A surface and the scanning of the transducer 4 is not parallel to the board surface,
For example, in the case of a curved surface such as a bridge pier with a circular cross section shown in FIG. 7, or in the case where the guide 3 and the base A are not parallel.

As an example, as shown in FIG. 8, if the scanning lines of the board A and the transducer 4 are not parallel, data as shown in FIG. 9 will be obtained. B ₁ , B ₂ in the diagram
is a hole dug on the scanning line of adult B that reaches the base A, and the broken line connecting B ₁ and B ₂ in Fig. 9 indicates the base A surface.

This broken line equation l is expressed as l _b =l _b1 +l _b2 -l _b1 /S _b2 -S _b1 (S-S _b1 )...(1). Therefore, l _t =l _b1 +l _b2 -l _b1 /S _b2 -S _b1 (S - S _b1 ) - l ...(2) is a value close to the layer thickness of adult organism B, but the direction of the ultrasonic wave to be measured is tilted with respect to the base A surface, so to correct this, l _t = COS [tan ^-1 {l _b2 −l _b1 /S _b2 −S _b1 }]
×[l _b1 +l _b2 −l _b1 /S _b2 −S _b1 (S−S _b1 )−l]…(3).

The arithmetic unit 19 extracts the two largest values from the distances l ₁ ...l _o from the reflective surface stored in the memory together with their corresponding scanning positions, and calculates (1) to
A correction calculation section is provided which calculates the layer thickness l _t value of the adult organism by performing the calculation of equation (3).

By providing such a mechanism in the calculation unit 19, this device can be effectively used in places such as bridge piers, and the length of the support leg 1 can be shortened to reduce the weight of the device. It can be moved and installed easily. Furthermore, since it is only necessary to make two holes in the adult B, it is not necessary to make the same number of holes as there are supporting legs 1, and the work is reduced.

[Brief explanation of the drawing]

Figure 1 of the accompanying drawings is a front view of a layer thickness measuring device for underwater organisms embodying the present invention, and Figure 2 is a view of Figure 1
An X-ray section plan view, Fig. 3 is a block diagram of the calculation unit, Fig. 4 is an explanatory diagram of the state of use seen from the side,
Figure 5 shows the pulses transmitted and received by the transducer, Figure 6 is a diagram of the measured values calculated by the calculation section, Figure 7 shows the installation state when used on a bridge pier, and Figure 8 shows the scanning line parallel to the base. FIG. 9, which is an explanatory diagram of a measurement state in which the sensor is not in use, shows data when measured in the state shown in FIG. 4... Transmitter/receiver, 5... Scanning body, 16... Transmitting section, 17... Receiving section, 19... Calculating section.

Claims (1)

[Claims] 1. A scanning mechanism that moves an ultrasonic transducer linearly underwater to measure distance underwater; a transmitter that emits an ultrasonic signal from the ultrasonic transducer;
It consists of a receiving section that receives the reflected signal of the emitted ultrasound, and a calculation section that stores the data of the transmission and reception section and calculates the distance from the stored data. and a calculation device that calculates the layer thickness of the product based on the difference between the distance measured by the time interval between the transmitted pulse and the received pulse and the distance from the substrate to which the adult organism is attached, and and a correction calculation unit that calculates the distance between the two points, takes the two longest distances among the calculated distances, and recalculates the layer thickness of the adult organisms using the straight line connecting these two points as a reference. Device for measuring layer thickness of adult organisms.