JPH10186029A - Underwater position detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a position with good accuracy over a wide range by measuring the coarse azimuth of a target with an inside array pair, then making high- accuracy measurement with an outside array pair. SOLUTION: A transceiver 20 transmits acoustic waves and receives the reflected waves from a target, and a phase difference measuring instrument 40 measures the phase difference of the acoustic waves. A detector 10 controls the operation of the transceiver 20 and calculates the position of the target from the phase difference. A third and fourth array pair having the center distance larger than that of a first and second array pair and making the straight lines connecting their centers nonparallel are provided on the transceiver 20 provided with the first and second array pair making the straight lines connecting their centers nonparallel. The coarse azimuth θof the target is measured by the inside first and second array pair, then the position of the target is measured with high accuracy by the outside third and fourth may pair.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a target underwater position by a split beam method.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing an example of the configuration of a conventional underwater position detecting device. FIG. 4 is a block diagram showing a sound wave transmitted from the underwater position detecting device shown in FIG. FIG. 4 is a sectional view of a sound wave in a vertical direction.

As shown in FIGS. 3 and 4, this conventional example is composed of two pairs of arrays, front and rear, left and right, and transmits and receives a sound wave to a target and receives a reflected wave from the target. , A phase difference measuring device 140 for measuring a phase difference of a sound wave received by the transducer 120,
Detector 110 that controls the operation of the device and calculates the position of the target from the phase difference measured by phase difference measuring device 140, CRT 130 that displays the phase difference measured by phase difference measuring device 140, and phase difference measuring device And a recorder 150 for recording the phase difference measured at 140.

In the underwater position detecting device configured as described above, the phase difference between the transmitted and received sound waves is measured by two sets of front, rear, left and right arrays, and the target position is calculated from the phase difference.

If the distance between the centers of the arrays is d and the direction of the target is θ, the difference between the distance between each array and the target is d · sin θ. The phase difference is (d · sin θ / λ) · 2π, where λ is the wavelength.

Here, if the condition of -π <d · sin θ / λ <π is satisfied, the position of the target can be measured.

[0007]

However, in the prior art as described above, the response is improved by increasing the value of d. However, in order to satisfy the above condition, θ
Range becomes narrow.

If the value of d is reduced, the range of θ is widened, but the response of the phase difference is deteriorated, and the measurement error is increased.

Therefore, there is a problem that one of the target detection range and the position detection accuracy must be sacrificed in the measurement.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has an underwater position detection method capable of performing accurate position detection without narrowing a target detection range. It is intended to provide a device.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention comprises a first and a second array pair in which straight lines connecting their centers are not parallel to each other. A transducer for transmitting a sound wave and receiving a reflected wave from the target, a phase difference measuring instrument for measuring a phase difference of the sound wave received by the transducer, and controlling the transducer to control the phase difference. A detector that calculates the position of the target from the phase difference measured by the measuring device, a display that displays the phase difference measured by the phase difference measuring device, and a phase difference measured by the phase difference measuring device And a recorder for recording, wherein the transducer has a larger center-to-center distance than the first and second array pairs and connects the centers of the two. The third and fourth lines are not parallel to each other
Characterized by having an array pair of

(Operation) In the present invention configured as described above, the first and second transducers provided with the first and second array pairs in which the straight lines connecting the centers thereof are not parallel to each other are provided. Third and fourth array pairs having a larger center-to-center distance than the two array pairs and straight lines connecting the centers thereof are not parallel to each other are provided, and the first and second inner array pairs are provided. The rough direction θ of the target is measured by the array pair of (1), and then the third and fourth array pairs (outer array pairs) measure the position of the target with high accuracy.

In this manner, accurate position detection is performed without narrowing the target detection range.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an underwater position detecting device according to the present invention. FIG. 2 is a diagram showing a sound wave transmitted from the underwater position detecting device shown in FIG. FIG. 4 is a sectional view of a sound wave in a vertical direction.

As shown in FIGS. 1 and 2, the present embodiment is composed of two pairs of arrays having different center-to-center distances in the front, rear, left and right directions, transmits a sound wave to a target, and generates a reflected wave from the target. The receiving transducer 20, the phase difference measuring device 40 for measuring the phase difference of the sound wave received by the transducer 20, and controlling the operation of the transducer 20 and from the phase difference measured by the phase difference measuring device 40 A detector 10 for calculating the position of the target; and a CRT 3 as a display for displaying the phase difference measured by the phase difference measuring device 40
0 and a recorder 50 for recording the phase difference measured by the phase difference measuring device 40. Here, in the array of the transducers 20, two array pairs, that is, a first array pair and a third array pair having different center-to-center distances are arranged so as to be arranged in the left-right direction. Two sets of array pairs, the second and fourth array pairs having different center-to-center distances, are arranged.

In the underwater position detecting device constructed as described above, of the two array pairs of the front, rear, left and right, first, the first and second array pairs, which are the inner array pairs, are roughly θ. Is measured, and then a highly accurate measurement is performed on the outer and third array pairs.

In this case, the phase difference between the outer arrays is ±
The phase difference between the inner arrays is not limited to ± π but is limited to ± π.

Therefore, highly accurate position detection can be performed over a wide range.

In the present embodiment, the third array pair is arranged so as to be aligned with the first array pair, and the fourth array pair is arranged so as to be aligned with the second array pair. The present invention is not limited to this, and the straight lines connecting the centers of the third array pair and the fourth array pair may not be parallel to each other.

[0021]

As described above, in the present invention,
A transducer provided with first and second array pairs in which straight lines connecting the respective centers are not parallel to each other is provided with a larger center-to-center distance than the first and second array pairs. The straight lines connecting are not parallel to each other
And the fourth array pair is provided, and the rough direction θ of the target is measured in the first and second array pairs which are the inner array pairs, and thereafter, the third array which is the outer array pair.
In addition, since highly accurate measurement of the position of the target is performed by the fourth array pair, highly accurate position detection can be performed over a wide range.

Further, by measuring a plurality of continuous pings, the swimming direction and speed of the target can be accurately calculated.

Further, the accuracy of position detection is improved, so that the accuracy of TS (target strength) estimation is also improved. These can be large parameters for fish species discrimination.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram showing an embodiment of an underwater position detection device according to the present invention.

FIG. 2 is a cross-sectional view of a sound wave in a direction perpendicular to a sending direction of the sound wave sent from the underwater position detecting device shown in FIG.

FIG. 3 is a block diagram showing a configuration example of a conventional underwater position detection device.

FIG. 4 is a cross-sectional view of a sound wave in a direction perpendicular to a sending direction of the sound wave sent from the underwater position detecting device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Detector 20 Transceiver 30 CRT 40 Phase difference measuring device 50 Recorder

Claims (1)

[Claims] 1. A transmission / reception system comprising: a first and a second array pair in which straight lines connecting centers thereof are not parallel to each other, for transmitting a sound wave to a target existing in water and receiving a reflected wave from the target. A wave detector, a phase difference measuring device for measuring a phase difference between sound waves received by the transducer, and a position of the target calculated from the phase difference measured by the phase difference measuring device while controlling the transducer. An underwater position detection device comprising: a detector that detects the phase difference; a display that displays the phase difference measured by the phase difference measuring device; and a recorder that records the phase difference measured by the phase difference measuring device. The transducer has a larger center-to-center distance than the first and second array pairs, and a third and fourth array pair in which straight lines connecting the respective centers are not parallel to each other. Underwater position detecting device characterized by.