JP3493121B2 - Ship sonar - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sonar for a ship using an ultrasonic wave transmitter / receiver, and more particularly to a sonar for a ship which is most suitable for a research ship or the like which sails in a shallow river while avoiding grounding. It is a thing.

[0002]

[Prior Art] For the purpose of investigating the condition of the bottom of a river and fishery resources, it is relatively large for a river with a weight of about 10 tons, but a special ship with a shallow draft of about 60 cm is used. Has been done. Such special vessels (below,
For the sake of convenience, abbreviated as "research vessel"), although it is relatively large in size, it is often necessary to enter a shallow water area with a depth of 1 meter or less for investigation, and often runs aground or riverbed. Accidents such as damage due to contact with will occur.

Assuming contact with such a grounding or riverbed, the hull of such a research ship has a flat structure with few protrusions and also has an FRP (reinforced plastic).
Manufactured using materials with sufficient strength such as. However, considering the labor and time required for the grounding work of a research vessel when it is grounded, it is necessary to avoid such grounding and contact with the riverbed as much as possible.

In order to avoid the grounding of the research ship and the contact with the river bottom as described above, the omnidirectional sonar which has been conventionally equipped on a fishing ship as a scanning sonar is used, and the distance to the obstacle in front of the research ship is used. Should be monitored. Conventionally, as such a sonar, there is one that is stored in the bottom of the hull at the center of the hull as shown by the dotted line in FIG. 6 and is projected below the bottom of the hull as shown by the solid line when in use.

Further, as illustrated in FIG. 7, a method in which an ultrasonic wave transmitter / receiver is installed on the bottom of the ship in the central portion of the hull and the oblique front side of the ship is monitored by using them can be considered. further,
As illustrated in FIG. 8, a simple type sonar in which an ultrasonic wave transmitter / receiver is installed at the tip of a rod lowered from the port side into the water and diagonally forward monitoring is also conceivable.

[0006]

Generally, a large amount of wave-breaking bubbles generated at the bow portion along with navigation flow into the bottom portion of the center of the hull. Therefore, as shown in FIGS. 6 and 7, in a sonar in which an ultrasonic wave transmitter / receiver is installed at the bottom of the ship in the center of the hull, ultrasonic waves are transmitted and received in order to prevent the propagation of ultrasonic waves from being obstructed by the bubbles. The corrugator is projected about 1 meter below the keel line on the bottom of the ship to a depth where bubbles are reduced. Therefore, it is difficult to apply the conventional sonar shown in FIGS. 6 and 7 to a research ship such as a water jet ship that requires entry into a shallow water area. In particular, the scanning sonar and pencil beam sonar of FIG. 6 are difficult to apply to a shallow depth research vessel because the scanning mechanism becomes large.

Even in the simple type sonar shown in FIG. 8, in order to avoid the interference by the wave-cutting bubbles generated at the bow portion, the ultrasonic transducer is placed about 1 meter below the keel line on the bottom of the ship to a depth where no bubbles are present. It must project, which is not suitable for research vessels for shallow depth.

Further, the scanning sonar and the pencil beam sonar are complicated and expensive devices exclusively used as a fish finder. In addition, the images of these sonars are expressed in a unique pattern, and the fishermen's specialists are observing the images, and the images are too complicated for the operator to monitor while maneuvering. There is also the drawback that it is difficult to do.

Therefore, one object of the present invention is to provide a sonar for a ship, which is optimum for a research ship for shallow depth. Another object of the present invention is to provide a marine sonar device capable of displaying an image that is intuitively easy to understand.

[0010]

A sonar for a ship according to the present invention is configured such that an ultrasonic transducer for forward monitoring and an ultrasonic transducer for depth monitoring are installed below a bow portion. ing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a preferred embodiment of a marine sonar of the present invention, each of the ultrasonic transducers for forward monitoring and depth monitoring has a bow that is about 10 cm above the keel line of the hull. It is installed on a pedestal attached near the centerline of the part.

According to another preferred embodiment of the marine sonar of the present invention, the ultrasonic wave transmitter / receiver for forward monitoring is installed so that the elevation / depression angle can be adjusted via a wedge-shaped spacer for elevation / depression angle adjustment. To be done.

According to still another preferred embodiment of the sonar for a ship of the present invention, each of the ultrasonic transducers for monitoring and for depth monitoring has a front surface of the metal housing inside the metal housing. It is fixed by retracting the wave transmission and reception surface, and is protected from damage due to collision with the river bottom or driftwood.

According to still another preferred embodiment of the marine sonar of the present invention, each ultrasonic transducer has a low Q characteristic for short-distance monitoring.

According to still another preferred embodiment of the marine sonar according to the present invention, the front display screen by the front and rear transducers and the depth display screen by the depth and front transducers are provided. It is displayed adjacently on the same display screen. Furthermore, the front display screen displays each measurement time point on the vertical axis that is upward and the measurement distance at each measurement time point on the horizontal axis,
The depth display screen is configured to be intuitively easy to understand by displaying each measurement time point on the horizontal axis and the depth at each measurement time point on the downward vertical axis.

[0016]

FIG. 2 is a block diagram showing the construction of a sonar for a ship according to an embodiment of the present invention. The sonar for a ship according to this embodiment includes a transducer (transceiver) 1 for forward monitoring.
a, a transmitter 2a and a broadband receiver 3a, a forward monitoring system, a depth monitoring transducer 1b, and a transmitter 2b.
And a depth monitoring system including a broadband receiver 3b, and a common part including a timing control circuit 4, a display device 5, an endless recording device 6, and a timer 7.

The front monitoring transducer 1a and the depth monitoring transducer 1b are made of stainless steel cases 10a, 10 having both corrosion resistance and strength.
As shown in FIG. 1, each case 10a, 10b is housed in a case b and is made of a reinforced plastic (FRP) pedestal 11 mounted so as to straddle the center line below the bow of the vessel V.
It is attached to each of the front and bottom of the. The bottom of this pedestal 11 is located at a position 10 lower than the keel line K at the bottom of the hull.
It is attached to the lower part of the bow so that it is located about cm above.

The case 10a of the front monitoring transducer 1a is attached to the front surface of the pedestal 11 with a slight depression angle while interposing a wedge-shaped spacer 12 for adjusting the elevation / depression angle. This depression angle is given in order to cancel the upward bow (elevation angle occurring on the hull) of the vessel when the ship is navigating, and to properly detect the dangerous shallow water hidden under the water surface in front. However, if this depression angle is too large, the dangerous riverbed in the front is mistakenly recognized as an obstacle in the front. Therefore, wedge-shaped spacers having various angles are prepared so that the depression angle can be adjusted variously according to the hull structure, the navigation depth, and the like.

A cable 13 drawn out from the transducers 1a and 1b housed in the cases 10a and 10b.
Is connected to the respective transmitters and broadband receivers of the forward monitoring system and the depth monitoring system, which are installed inside the ship, through the waterproof pipe 14. Considering that the underwater bow part is the part where the maximum water pressure acts when the ship is navigating, pull the cable directly into the ship through the spacer 12, pedestal 11 and waterproof pipe 14 without exposing the cable to the water. It has a structure. Since the upper end of the waterproof pipe 14 is set at a position higher than the waterline, even if the watertightness of the underwater portion is imperfect and water enters the inside, ingress of water into the ship is effectively prevented.

The wedge-shaped spacer 12 is made of stainless steel, and as shown in the front view of FIG. 3 and its sectional view taken along the line AA ', the wedge-shaped spacer 12 is symmetrical around the center line indicated by the one-dot chain line in the plan view. It has a shape. Due to this symmetry, the wedge-shaped spacer 12 can be used by turning it upside down to provide the same depression angle and elevation angle with a single spacer. The smooth U-shaped notches formed in the upper and lower central portions of the wedge-shaped spacer 12 are recesses through which the cable drawn from the transducer passes.

The front monitoring transducer 1a is housed inside a stainless steel case 10a having both the corrosion resistance and strength of the structure shown in the front view and side view of FIG. The front end face of the transducer 1a is the case 1
It is set back a few millimeters from the front end face of 0a.
This is because even if an obstacle such as driftwood, rock, or an underwater structure collides with the case 10a, the front end face of the transducer 1a is not contacted and the transducer is prevented from being destroyed. The relationship between the depth monitoring transducer 1b and its case 10b is the same as that of the forward monitoring described above. In addition, the cable insertion hole formed in the wedge-shaped spacer 12 and the pedestal 11 behind the wedge-shaped spacer 12 is shielded by the case 10a, so that it is not directly affected by water pressure.

Referring again to FIG. 2, the transducer 1a for forward monitoring and the transducer 1b for depth monitoring are also included.
Also, under the control of the timing control circuit 4, ultrasonic waves of about 88 kHz are alternately transmitted in bursts for a time of 200 μsec to 500 μsec, and corresponding reflected signals are received. And the transducers 1a, 1b
All have low Q (for example, about 5 to 10) electrical characteristics for monitoring a shallow depth of about 50 cm. This low-Q electrical characteristic avoids repetitive generation of a transmission signal, and has an optimal characteristic for monitoring shallow depth where the time from transmission to reception of a reflected wave is short. In addition, preferably, the width of the ultrasonic beam emitted from the transducer for forward monitoring is set to be wider than that for monitoring depth.

The receiver is 6 dB for both forward monitoring and depth monitoring.
It has wide-band characteristics with a width of about 40 kHz, and faithfully reproduces the envelope waveform of the received burst-like reflected wave. The received reflected waves amplified by the wide band receivers 3a and 3b are transferred to a display device, where a front display screen 5a and a depth display screen 5b which are processed and adjacently formed for a well-known B scope display are formed. Displayed on each. This display device
A conventional dual-frequency simultaneous writing type display device is used for display as it is. That is, the conventional dual frequency simultaneous display device radiates burst ultrasonic waves of two frequencies having different propagation characteristics toward the bottom of the water, and displays the reflected wave on the adjacent screen by B scope display. It is configured to obtain more detailed observation results.

In this dual frequency simultaneous display system, the time axis is set leftward and the distance to the reflector is set downward in both the front display screen and the depth display screen. However, as a conventional method applied to the display screen of this type of sonar, the arrow on the time axis indicates the retrospective direction of time. According to such a display screen, it is possible to intuitively understand how the depth of the river bottom changes with time on the display screen for depth monitoring. On the other hand, on the front monitoring display screen, the change in the distance to the front reflector may be misunderstood as if the change in depth.

Therefore, in order to avoid the above misunderstanding, the display method of the front display screen is changed. First, as shown in FIG. 5 (A), from each transducer, burst ultrasonic waves are alternately transmitted obliquely slightly below and just below the ship, from the transmission of ultrasonic waves in each direction to the reception of their reflected waves. Is halved and the time required for one-way propagation to the ultrasonic reflector is calculated. The propagation speed of the ultrasonic pulse that is almost constant is divided by this propagation time, obstacles in front,
The distance to the reflector that generated the reflection pulse, such as the bottom of the river directly below, is calculated and displayed on the screen.

The display method of the depth display screen is shown in FIG.
As shown on the left side of, the time axis is set to the left and the depth is set to the downward, as in the conventional case. On the other hand, as shown in the right side of FIG. 5B, the front display screen 5a includes a time axis set downward and a distance axis set rightward, and is detected at each time point. A curved line connecting the distances to the reflected reflectors is displayed on the screen. Figure 5
The display screen on the right side of (B) is for driftwood, underwater structures,
An example is shown in which an underwater obstacle in the front such as a stepped shallow water is approaching every moment. The observer of this display screen can intuitively understand the danger of an imminent collision because the displayed curve is approaching the origin. In addition, it is displayed in decimal notation that the distance to the reflector, which is the latest detection result, is 2 m.

The depth display screen of FIG. 5B illustrates how the depth to the river bottom changes moment by moment. The observer of this display screen intuitively realizes that there is no immediate danger of grounding as far as depth is concerned, since the displayed curve is sufficiently below. In addition, the fact that the distance to the riverbed, which is the latest detection result, is 3 m is displayed in decimal.

The most characteristic feature of the marine sonar of the present invention is that the transducer is attached to the bow portion where a large amount of wave breaking bubbles are generated. Although a large amount of wave-breaking bubbles are generated at this bow part, they are swiftly swept backward due to the large water pressure difference generated along the traveling direction, so that the blockage of bubbles in the front of the case disturbs these cases. Less than when mounted in the center. As a result, it is not necessary to install a transducer below the hull in order to avoid the interference of wave breaking bubbles, and it is possible to use it in shallow water.

Conventionally, attachment of a protrusion such as a transducer to the bow portion has been avoided because there is a strong possibility of impairing the navigation function such as the stability of the marine vessel maneuvering. However, even for a small vessel with a gross tonnage of about 15 tons, the protruding size of the transducer is 7.5 cm.
By reducing the size to about 15 cm x 15 cm, there is no particular problem in terms of navigation functions such as stability of marine vessel maneuvering when the cruise speed is relatively low up to about 20 knots. The result turned out.

According to the experimental results of the present invention, the mounting position of the transducer is set at 10 degrees from the keel line at the lowermost end of the hull.
It is attached to the lower part of the bow so that it is located about cm above. This is because the transducer does not protrude above the surface of the water even when the bow rises when the ship is navigating.
It is desirable to install this as low as possible, but if it is installed below the keel wire at the same level or lower, the transducer will be damaged by the ship bottom coming into contact with the river bottom.

In the above, the configuration in which the ultrasonic beam for forward monitoring is radiated downward has been illustrated. However, considering that the ultrasonic beam incident on the water surface from the underwater at a shallow elevation angle is totally reflected and returns to the water at a shallow elevation angle, a configuration in which the ultrasonic beam is radiated toward the water surface at a shallow elevation angle can be adopted.

[0032]

As described in detail above, in the sonar for a ship of the present invention, an ultrasonic transducer for forward monitoring and an ultrasonic transducer for depth monitoring are installed below the bow portion. As a result, a sonar for vessels, which is suitable for research vessels for shallow depths, whose function is not impaired by wave breaking bubbles is provided.

Further, according to the preferred embodiment of the marine sonar of the present invention, the front display screen and the depth display screen are displayed adjacent to each other on the same display screen, and preferably, for each display screen, respectively. Since different display methods suitable for the above are applied, an intuitive understanding is facilitated, and the operator can appropriately monitor the front and the depth while maneuvering the ship.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a mounting structure of a transducer of a sonar for a ship to a hull V of an embodiment of the present invention.

FIG. 2 is a functional block diagram showing a configuration of a ship sonar according to an embodiment of the present invention.

3A and 3B are a plan view and a cross-sectional view showing the structure of a wedge-shaped spacer used in the above embodiment.

4A and 4B are a front view and a side view showing a structure of a transducer used in the above embodiment and a case accommodating the same.

FIG. 5 is a conceptual diagram showing an example of a ship situation (A) and a display screen (B).

FIG. 6 is a conceptual diagram showing an example of the configuration of a conventional ship sonar.

FIG. 7 is a conceptual diagram showing another example of the configuration of a conventional ship sonar.

FIG. 8 is a conceptual diagram showing still another example of the configuration of a conventional marine sonar.

[Explanation of symbols] V hull 1a Transducer for forward monitoring 1b Depth monitoring transducer 10a Transducer case for forward monitoring Transducer case for 10b depth monitoring 11 pedestal 12 wedge spacer 13 cable

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-31042 (JP, A) JP-A-8-282582 (JP, A) JP-A-8-249060 (JP, A) JP-A-4- 204282 (JP, A) JP 61-77777 (JP, A) Actually open 3-65993 (JP, U) Actually open 61-21987 (JP, U) Actually open 63-12785 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01S 15/00-15/96 G01S ⁷ /52-7/64

Claims (8)

(57) [Claims] 1. A ship in which an ultrasonic transducer for forward monitoring and an ultrasonic transducer for depth monitoring are located above the keel line of the hull.
A ship sonar characterized by being installed on a pedestal attached near the center line of the neck . 2. The marine sonar according to claim 1 , wherein the pedestal is attached about 10 cm above the keel line of the hull. 3. The ultrasonic wave transmitter / receiver for forward monitoring according to claim 1 or 2 , wherein the elevation / depression angle is adjustable via a spacer for adjusting the elevation / depression angle. Sonar for ships. 4. The marine sonar according to claim 3 , wherein the spacer is wedge-shaped. In any of 5. A method according to claim 1 to 4, wherein each ultrasonic transducer is characterized by being fixed to retract the transmitting and receiving surface than the front surface of the metal housing in the interior of the metal housing Sonar for ships. In any one of claims 6] claims 1 to 5, the ultrasonic transducer for the depth monitoring, marine sonar, characterized by having the properties of low Q for short distance monitoring. 7. The display according to any one of claims 1 to 6 , wherein the front display screen by the ultrasonic transducer for front monitoring and the depth display screen by the ultrasonic transducer for depth monitoring are the same display. A sonar for a ship, which is displayed adjacently on the screen. 8. The front display screen according to claim 7 , wherein each measurement time point is displayed on the vertical axis, and the measurement distance at each measurement time point is displayed on the horizontal axis, and the depth display screen displays each measurement time point. Is displayed on the horizontal axis and the depth at each measurement point is displayed on the vertical axis.