JP2641666B2 - Semi-circular scanning 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 semicircular scanning sonar.

[0002]

2. Description of the Related Art FIG. 4 is an explanatory view showing a method of detecting a school of fish using a conventional half-circle scanning sonar, and FIGS. 5A and 5B.
FIGS. 6A and 6B show a method of driving an ultrasonic beam by the semicircular scanning sonar of FIG. 4; FIGS.
It is a figure which shows the screen display on CRT of (B).

[0003] The transducer of the semicircular scanning sonar is
Normally, multiple transducers are arranged on more than half of the peripheral surface on a cylinder,
The center in the detection direction is set in front of the plane on which the transducers are arranged (that is, the center of the transmission and reception beams).

When the direction of the depression angle θ in the direction in which the own ship travels is set as the center of the detection direction (FIGS. 4 and 5A), the detection screen is C
It is displayed on the RT as shown in FIG. If a fish school is found in the direction of the turning angle 中 in this detection screen and the center of the transmission / reception beam is directed toward the fish school as it is, the fish school disappears. This is because the transmitting / receiving beam is inclined below the angle of depression θ (for example, 15 °), so that the transmission / reception beam goes below the school of fish at the depression angle θ _F (θ _F <θ) (FIG. 5B). Therefore, in the related art, the fish school is displayed by turning the transducer by the turning angle ψ, changing the depression angle by the amount of experience, and setting the depression angle to θ _F (for example, 10 °).

[0005]

The above-described conventional half-circle scanning sonar has the following problems when the transducer is turned and the object to be detected disappears from the screen. (1) Although the depression angle is changed after turning with the aim, it may be lost due to the movement of the fish school or own ship during the mechanical change. (2) Since the calculation of the angle cannot be easily obtained by mental arithmetic, it is necessary to repeatedly operate the depression angle to re- catch the school of fish. It is very complicated and time-consuming.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a semi-circular scanning sonar in which when a transducer is turned, a depression angle is automatically adjusted toward a fish school found before turning. And

[0007]

SUMMARY OF THE INVENTION A semicircular scanning sonar according to the present invention tilts a transducer with respect to a rotation center axis at a predetermined depression angle θ so that the center of the detection direction is directly in front of the transducer. This is a semicircular scanning sonar that turns the turning angle 周 り around a rotation center axis to detect underwater, and a detection state at a depression angle θ ₀ in order to direct the transducer directly in front of a detection target other than the center in the detection direction. From the turning angle ψ in _one direction
To change the detection direction, an arithmetic control unit for driving the transducer is calculated based on the new depression theta following equation ^{_{F θ F = tan -1 (tanθ}} 0 · cosψ 1).

[0008]

[0009]

[Action] When the detection target is found outside the center of the detection direction, if the transducer is turned to the detection target, the depression angle θ is automatically changed, and the detection target is captured. The new depression angle θ _F is the previous depression angle θ ₀ And turning angle ψ ₁ From θ _F = tan
^-1 (tan θ ₀ ・ Cos @ ₁ ). here
Now, the basis of the equation for the new depression angle θ _F will be described with reference to FIG.
You. In Fig. 7, the position of the school of fish is point A, the front of the transducer.
The azimuth angle of the school of fish (point A) from the direction ψ, xy plane from point A
The point at which the perpendicular to the xy plane intersects is centered on points B and O,
A straight line OE at which the semicircular surface of the depression angle θ ₀ and the yz plane intersect, and a point A
The point where the perpendicular from the line to the straight line OE intersects the C, y axis and the point B
Assuming that the point at which the perpendicular to the y-axis intersects the y-axis is D, ψ ₁ = ψ tan θ ₀ = DC / OD, cosψ ₁ = OD / OB, and tan θ _F = AB / OB . Here, DC = because the _{AB tanθ F = tanθ 0 · cosψ} 1 than this ^{_{θ F = tan -1 (tanθ 0}} · cosψ 1) is obtained.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a semi-circular scanning sonar of the present invention, FIG. 2 is a diagram showing a method of driving an ultrasonic beam in the embodiment of FIG. 1, and FIG. 3 explains the operation of the embodiment of FIG. FIG.

The turning correction switch 1 designates whether to perform the depression angle correction manually as in the prior art or automatically according to the present invention. When the turning correction switch 1 designates manual operation, the turning control unit 2 and the depression angle control unit 6 drive the motors 4 and 8 according to the operations of the turning control switch 3 and the depression angle control switch 7, respectively. (Illustration) is set. In the following, a case where the turning correction switch 1 designates automatic will be described. Turning control unit 2
Is based on a turning command Iψ (hereinafter referred to as a command Iψ).
The motor 4 is driven to rotate the transducer by the designated turning angle ψ about the rotation center axis. The turning detector 5 outputs turning azimuth information Dψ (hereinafter referred to as information Dψ) indicating how much the transducer has been turned by the motor 4. The depression angle control unit 6 drives the motor 8 based on the depression angle command Iθ (hereinafter, referred to as the command Iθ), and tilts the transducer by the indicated depression angle θ with respect to the rotation center axis. The depression angle detector 9 outputs depression angle information Dθ (hereinafter, referred to as information Dθ) indicating how much the transducer is tilted by the motor 8. The pointing device 11 is a trackball or a joystick, and specifies the position of a tracking marker on the display screen of the CRT 14. The graphic display unit 12 creates display data by synthesizing the detected image signal SS and a tracking marker whose display position is designated by the pointing device 11, and outputs the display data to the CRT 14 according to an instruction from the arithmetic unit 20. The display control unit 13 determines a sweep timing and a display timing according to an instruction from the arithmetic unit 20, and performs a raster sweep for displaying an image based on the display data of the graphic display unit 12 on the CRT 14. The operation unit 20 outputs the commands Iψ and Iθ to the turning control unit 2 and the depression angle control unit 6 respectively.
And the attitude of the transducer is controlled, and the attitude of the transducer is detected from the information Dψ and Dθ. Further, it instructs the graphic display unit 12 and the display control unit 13 to detect the detected image signal S formed based on the echo received via the transducer.
The detected image is displayed on the CRT 14 by S,
The tracking marker MK is displayed at the position specified by the pointing device 11. The arithmetic unit 20, if the position of the tracking markers MK is instructed to differ by pivot angles [psi ₁ and the center of the transmitting and receiving beams, turning the center of the transmitting and receiving beams and outputting a turning command Iψ the turning control section 2 While turning by the angle ψ, a new depression angle θ _F is calculated from the depression angle θ ₀ according to the equation (1), and the depression angle command Iθ is output to the depression angle control unit 6 to set the depression angle to the depression angle θ _{F. ^{θ F = tan -1 (tanθ 0}} · cosψ 1) ... (1) will now be described with reference to FIG. 3, the operation of this embodiment. When the pointing direction A of the own ship SF and the beam center direction B are in the same vertical plane, the tracking marker MK is displayed in the pointing direction as shown in FIG. LT15 at the top right of the screen
° represents the depression angle θ ₀ . I found fish to the turning angle [psi ₁ to tracking marker MK direction during detection, to direct the beam center direction B in shoal of fish, moves in fish direction finding tracking marker MK by operating a pointing device 11 (FIG. 3
(B)). Calculation unit 20 detects a pivot angle [psi ₁ from the instruction information Dψ and a pointing device 11, and outputs the turning command Aipusai, theta by the aforementioned formula (1) _F
And outputs the depression angle command Iθ. When the turning angle and the depression angle of the transducer are changed and the beam center direction B matches the new designated direction A, the transducer is displayed as shown in FIG. Note that FIG. 3C shows that the depression angle has been changed to 10 ° as a result.

[0012]

As described above, according to the present invention, when the transducer is turned to aim the beam center at the detected object to be detected, at the same time, the depression angle is automatically corrected toward the object to be detected. There is no hassle such as performing the depression angle operation by complicated calculations or correcting the depression angle by aiming without repeatedly losing the detected detection target object.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a semicircular scanning sonar of the present invention.

FIG. 2 is a diagram showing a driving method of an ultrasonic beam in the embodiment of FIG.

FIG. 3 is a diagram for explaining the operation of the embodiment of FIG. 1;

FIG. 4 is an explanatory diagram showing a method of detecting a school of fish using a conventional half-circle scanning sonar.

FIG. 5 is a diagram illustrating a method of driving an ultrasonic beam of the semicircular scanning sonar of FIG. 4;

FIG. 6 is a diagram showing a screen display on the CRT in FIGS. 5A and 5B.

FIG. 7 is for explaining the basis of a new formula for calculating the depression angle θ _F
FIG.

[Explanation of symbols]

 Reference Signs List 1 turning correction switch 2 turning control unit 3 turning control switch 4, 8 motor 5 turning detection unit 6 depression angle control unit 7 depression angle control switch 9 depression angle detection unit 11 pointing device 12 graphic display unit 13 display control unit 14 CRT 20 calculation unit

Claims (1)

(57) [Claims] 1. A semi-circular scanning sonar for detecting underwater by inclining a transducer at a predetermined depression angle θ with respect to a rotation center axis and changing a turning angle 回 り around the rotation center axis, except for the center in the detection direction. The turning angle ψ ₁ from the detection state at the depression angle θ ₀ so that the transducer
Lower the new depression angle θ _F to change the detection direction to
Half type scanning sonar, characterized in that it comprises an arithmetic control unit for driving the transducer is calculated based on the formula ^{_{θ F = tan -1 (tanθ 0}} · cosψ 1).