JP2885989B2 - Scanning sonar and its detection and display method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitter / receiver in which a plurality of transducers are vertically arranged in a plurality of rows or columns and arranged in a cylindrical or arcuate manner. The present invention relates to a scanning sonar capable of detecting and displaying a direction in real time.

[0002]

2. Description of the Related Art A conventional scanning sonar is shown in FIG.
As shown in (a) and (b), a vertically arranged transducer formed by laminating a plurality of transducers as shown in (a) and (b) is used. Transmit beam TB
And receiving is performed at a high speed in the azimuth φ direction over the entire circumference 360 ° every azimuth scanning period T _H within the transmission period T _{X as} shown in FIGS. 5 (b), (c) and (d). done via a reception beam RB that is pivoted scanned, flat screen (hereinafter HG for flat display of the reflector, such as a school of fish F in depression theta ₁ direction (hereinafter simply referred to as fish) reflected signals from the FIG. 5 (c) PPI is displayed on the screen. Next, the depth display of the fish school to be detected is indicated by the fish school F on the HG screen as shown in FIG.
Each time the reception beam passes between the azimuth marks φ _{1 to} φ ₂ appropriately selected in the direction shown in FIG.
Vertical screen (hereinafter referred to as VG screen)
It displayed as fish unit image F (average value or the maximum value) on a scanning line that is swept into the depression angle theta ₁ direction above. The depth of the school of fish is read on a suitable depth scale, which is omitted in the figure. Next, detection and display of the distribution and shape of the school of fish in the depth direction are performed by the depression angle of the transmission beam TB and the reception beam RB and the VG.
The sweep angle (depression angle) of the scanning line on the screen is sequentially switched to θ ₁ , θ _2, ... At an appropriate angle θ _S simultaneously in each transmission cycle, and detection and display are performed. FIGS. 5C and 5D show an example in which the depression angles θ ₁ and θ ₂ are detected in _two transmission cycles, and the fish schools F and F ′ in the two depression angles are displayed. After the plurality of detections in the depression angle direction are performed in each transmission cycle in this manner, the distribution, shape, and the like of the fish school in the depth direction are observed from the entire fish school image on each scanning line on the obtained VG screen. Note that the detection and display method when the vertically arranged transducers of the transducers are arranged in an arc shape is the same as described above except that the detection width in the azimuth direction is different from that for the entire circumference, and thus will be briefly described.

[0003]

To detect and display a three-dimensional space which is wide in the depression angle direction over the entire circumference by the conventional scanning sonar, it is necessary to detect and display a large number of depression angles in one transmission cycle. Since only the detection in one depression angle direction and the received image on the scanning line in one depression angle direction can be obtained, it takes time to detect and display the entire space. Also as in the VG screen shown in FIG. 5 (c) in order to shorten the detection time, the depression angle switching換角degree during transmission θ
_{If S} is made larger than the receiving beam and the switching speed is increased, the gap between the scanning lines will be enlarged, and the school of fish will be displayed sparsely in the depression angle direction, making it difficult to recognize the school of fish and understand the distribution status, and at the same time, the school of fish And discrimination of noise is hindered, and the detection ability is reduced. Since decreasing the depression angle switching換角degree theta _S for the above reasons, there is a disadvantage that it takes time to detect the display of the entire space. In addition, in order to simultaneously detect a plurality of depression angles, using a plurality of receivers separately for each depression angle has the disadvantage of increasing the cost.

SUMMARY OF THE INVENTION It is an object of the present invention to detect a wide space in the direction of depression over the entire circumference as described above by switching the depression angle for each transmission cycle and displaying one scan line at a time, so that it takes time to detect the entire space. Further, if the depression angle switching angle is increased to shorten the detection time, the space between the scanning lines on the VG screen increases, making it difficult to observe the image. In addition, the receiver is required for parallel detection in a plurality of depression angles. In the case where a plurality of are used together, in consideration of the problem that the cost is increased, the azimuth scanning of the reception beam is performed every time the azimuth scanning is performed, and the entire circumference in the plurality of depression angles is sequentially and repeatedly detected, and the adjacent beam is detected. In order to interpolate between a pair of received signals obtained by two depression angle azimuth scans, an appropriate number of multiplexed signals are created by combining the paired received signals at an appropriate distribution ratio. Can be displayed in parallel It is to try to provide a canning sonar.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided a scanning sonar detection and display method, comprising the steps of: arranging a plurality of vertically arranged transducers on a cylindrical surface, the transducers being arranged along a cylinder axis; In a scanning sonar using a transducer in which the vertically arranged transducers cover at least a part of the cylindrical surface on average, in a wide depression angle, the vertically arranged transducer transmits a transmission beam directed to the entire circumference facing the same, The depression angle of the received beam is sequentially changed by a predetermined angle within a predetermined range for each azimuth scanning cycle, azimuth scanning is performed within a predetermined azimuth width, an azimuth scanning output is output, and an adjacent azimuth scanning cycle. A signal for forming an interpolated scan output for compensating for the reception time difference between the azimuth scan outputs and interpolating between the scan outputs is formed, and an image is formed and displayed in real time using the azimuth scan output and the interpolated scan output.

A scanning sonar according to the present invention is characterized in that a plurality of vertically arranged vibrators arranged on a cylindrical surface along a cylindrical axis are arranged in a plurality of rows. In a scanning sonar using a transducer that averagely covers at least a part of the cylindrical surface, a transmitting unit that transmits a transmitting beam directed to the entire circumference with a wide depression angle width,
A depression angle scanning unit that repeatedly changes the depression angle of the reception beam by a predetermined angle within a predetermined range for each azimuth scanning cycle, and a predetermined azimuth width for each depression angle set by the depression angle scanning unit Azimuth scanning means for azimuth scanning, delay means for giving a delay of one azimuth scanning cycle to the azimuth scanning output of the azimuth scanning means, and outputting as a delay output; Signal forming means for outputting an interpolated scan output for interpolating between azimuth scan outputs in a scan cycle, and image display means for forming and displaying an image in real time using the azimuth scan output and the interpolated scan output for each azimuth scan cycle. Have. Further, it is preferable that the signal forming means outputs a multiplexed signal in which the azimuth scan output and the delay output are appropriately distributed as an interpolation scan output.

[0007]

Since the scanning sonar of the present invention is constructed as described above, while receiving the echo of the transmission beam transmitted over the entire circumference with a wide depression angle transmitted by the transmission circuit in each transmission cycle, the depression angle scanning means is used. The azimuth scanning means scans within a predetermined depression angle width and azimuth width. The signal forming means performs interpolation scanning for interpolating between adjacent azimuth scanning outputs, outputs an interpolation scanning output, and the image display means uses the azimuth scanning output and the interpolation scanning output for each azimuth scanning cycle in real time. An image is formed and a detected image is displayed.

For example, reception is performed as shown in FIGS.
Beam RB (: azimuth angle φ, depression angle θ) is azimuth scanning cycle T_H
(Hereinafter simply the period T_HEvery time)
In addition, the depression angle is an appropriate angle θ_S(Example: To prevent missing detection
Angle smaller than half-half angle)₁, Θ_Two, ..., θ
_qAnd the period qT_HIt is repeatedly scanned every depression
Is performed continuously during the transmission cycle,
The entire space is detected in real time, and the received signal is real
Taken out in time. Then the adjacent depression angle (eg: θ₁When
θ_Two), The period T_HBack and forth at intervals
As shown in FIG. 3 (c), two received signals extracted
Period preceding (# 1T_HAngle of depression θ)₁Obtained from
Received signal (S_Two) With period T_HTime delayed for take out
Received signal S₁(Referred to as the first signal) and the following
Period (# 2T_HAngle of depression θ) _TwoReceived signal obtained from
No. S_Two(Referred to as the second signal)
Simultaneously as a pair of time-series signals that equalize the detection directions
Be taken out. Next, as shown in the VG screen of FIG.
Depression angle θ₁And θ_TwoOpening angle θ_SIs divided appropriately (example: m
Depression angle δ set to +1 division)₁, Δ_Two, ...
・, Δ_mSignals to be displayed on the square scanning line (the third signal is
Lower multiplex signal) SS₁, SS_Two, ..., SS_mTo l
= 1, 2,..., M, the first signal S₁And the second
Signal S_Two Is given by the following equation (1).

[0009]

(Equation 1) Are formed by distributing and combining as shown in FIG. Here m = 6 Tosureba multiplexed signals _{SS 1, SS 2, ···,} SS m each equation (2)

[0010]

(Equation 2) It is formed as, and is output as the model of FIG. 2 (d). These multiplexed signals SS ₁ , SS ₂ ,..., SS _m
The received signal S _1, S ₂ and the depression angle _{δ 1, δ 2, ···,} δ m
And the relationship between θ ₁ and θ ₂ is shown in FIGS. 3 (c), (d) and (e). Then the received signal S _1, S ₂ and multiplex signals SS _1, SS _2, ···, from SS _m 2 of (c) HG
Signals between the azimuth width phi ₁ to [phi] ₂ of the screen is appropriately selected view 2
It is displayed like the VG screen of (c). Then depression scanned every cycle T _H as shown in FIG. 3 (b) as above is performed, and sequentially adjacent depression (eg: theta ₁ and theta _2, theta ₂ and theta
₃ ··· _{θ q)} multiplexed signal for multiple display between are formed in real time, V with real-time reception signal S ₂
It is displayed on the G screen and the HG screen. Incidentally received signal S shown in FIG. 3 (c) receiving signals depression angle theta ₁ in cycle # 1T _H
2 and is displayed as shown in the VG screen of FIG.

Since the period is generally about 1 ms,
When the depression angle switching azimuth number q is 4, the entire circumference of each of the four depression angles is detected every 4 ms, and the detection interval in the distance direction is about 3 mS. Therefore, the transmission pulse width when detecting a single fish is set to about 4 mS.

In this manner, a three-dimensional space that is wide in the depression direction over the entire circumference in one transmission cycle is detected in real time by the repetitive scanning of the reception beam that is scanned all around the q depression directions, and adjacent thereto. After time compensation of a pair of reception signals obtained at different times from the depression angle is performed, the reception signals are combined at an appropriate distribution ratio to form m multiplexed signals, and the obtained q time-series reception from the entire circumference is performed. Signal and m (q-1)
The time series reception signals corresponding to the entire circumference are q + m (q-1) scanning lines on the HG screen, and the signals between the azimuth widths φ _{1 and} φ ₂ in the reception signals and the multiplex signals are HG. It is displayed on the VG screen simultaneously with the screen in real time.

As described above, in the conventional method, the detection and the image display for each transmission cycle are the detection in one depression angle direction and the display on one scanning line, whereas in the detection and display method of the present invention, the detection and the image display are performed for each transmission cycle. Since the detection in the q depression angle direction and the parallel display of the q + m (q-1) scanning lines display an image without a blank portion in real time, the detection display does not take much time.

The school of fish that spreads in a three-dimensional space that is wide in the depression angle direction in this way is detected in real time for each transmission cycle, and is displayed on the HG and VG screens in real time by a large number of scanning lines. Recognition of an image and interpretation of a distribution state are easily performed, and noise discrimination is facilitated, thereby improving detection capability.

[0015]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the scanning sonar of the present invention.

Transmitter / receiver having the same structure as that of the transmitter 1
Combination of the container 2 and a wide depression angle θ as shown in FIG._W 
To form and transmit a transmission beam TB pointing in all directions.
N vertical arrangements stacked in k stages of the transducer 2 and directed in the n direction
The row vibrators 3 and 4 receive the signal S ₁₁~ S_1K, ..., S_n1~
S_nkIs output. Where the depression angle θ₁ ~ Θ_q Received signal in
No. S₁₁~ S_n1Received signal S for₁₂~ S_n2, ..., S
_1k~ S_nkPhase difference of each of the 2 to k layers
Angle of depression θ₁ ~ Θ_q Each phase difference when receiving _{twenty one}~
ψ_k1, ..., ψ_2q~ Ψ_kqAnd j = 2 to k and
And p = 1 to q, the phase difference ψ_{twenty one}~ Ψ_k1, ..., ψ_2q
~ Ψ_kqΨ_jpAbbreviated. The oscillator 6 of the depression angle scanner 5 is a station.
Outgoing signal L₁ Is output. The delay circuit 7 is a delay circuit with a tap.
The input signal L from each tap₁ Against
Phase difference ψ_jp(: Ψ_{twenty one}~ Ψ_kq) Signal group L_G Output
I do. The switching matrix 8 includes a signal group L_G Input
Line, local output L to phase shifters 10-11_Two ~ L_k Output
Electronic switch for switching and connecting
Control circuit D for controlling the switches₁~ D_q It is composed of System
Controller 9 has a period of # 1T as shown in FIG._H ~ # QT_H of
Period T_H Control line D for each₁ ~ D_q Are activated sequentially, and
Phase difference from the input line through the control line switches_{twenty one}
~ Ψ_k1, ..., ψ_2q~ Ψ_kqSequentially extract signals with
And the local output L of the output line_Two ~ L_k Each phase of the period T_H 
Switch simultaneously and instantly for each. The phase shifters 10 to 11
As before, the abbreviated modulator and synthesizer respectively
The received signal S₁₁~ S_n1, S₁₂~ S_n2, ...,
S_1k~ S_nk, L₁ , L_Two ~ L_k Changed by
To make them in-phase, and then combine them by each combiner.
And the period qT_H In the period T_H The depression angle is θ₁ ~
θ_q With a receive beam pointing to the n direction switched to
Signal S_V1~ S_VnIs output. Then instantly as described above
Switching depression angle scanning is cycle qT_H Real-time for each
And continue. Direction scanner 12 inputs in parallel
Received signal S from n directions_V1~ S_VnAs before as appropriate
Select, take out, and adjust the phase, as shown in FIGS. 2 (a) and 3 (a).
The horizontal directivity of the receiving beam RB and the period T_H Every
Scans the azimuth of the received signal S_Two In real time
Output. Thus, as shown in FIGS. 3 (a) and 3 (b)
Period qT _H Angle of depression θ₁ ~ Θ_q Full circumference for each direction
The detection is repeated sequentially in real time, and the received signal is
Output in real time. The multiplexing circuit 13 receives the input signal S_Two 
With the period T_H Time delay equivalent to
1 signal S₁ Output as Then the first signal S₁ When
Signal S input in real time_Two (The second signal
) Are input to m signal shapers (1-m) 15-17.
It is. The signal formers (1 to m) 15 to 17 are as described above and in the drawings.
2 (d) and depression angle switching angle θ as shown in FIG. 3 (e)._STo m + 1
Dividing angle δ₁ , Δ_Two , ..., δ_m Table on the scan line
Multiple signal SS shown₁ , SS_Two , ..., SS_m Formation
Each circuit is configured as shown in FIG. Each signal formation
The multipliers 21 and 22 of the multipliers 15 to 17 are calculated by the above equation (1).
Are multiplied by the first and second terms, respectively.
The adder 23 adds the outputs of the multipliers 21 and 22 and multiplexes them.
Signal SS_L(L = 1, 2,..., M) is output. these
The multiplex signal has a period T as shown in FIGS._H Each
Created between depressions and with a period qT_H Is repeated every time.
The converter 20 of the display 18 has a scan converter or the like.
And the multiplexed signal SS from the multiplexing circuit 13._L And received signal
S_Two To raster such as color CRT display for TV
The display screen of the display unit 18 having the display device shown in FIG.
Display on the HG screen,_L When
Received signal S_TwoDirection mark on HG screen from₁~ Φ_Two 
And the signal on the VG screen shown in FIGS.
Angle δ₁ ~ Δ_m And θ_Two Real-time on each scan line
To display an image.

As described above, during the transmission period, the period qT
The full-circumference detection for each q depression direction is repeated by composite scanning for each _H , time-series received signals of all the circumferences for each q depression direction are sequentially taken out in real time, and the period T _H for each adjacent depression angle.
M from the time series signal of the entire circumference for each pair of depression angles obtained before and after
Number of multiplexed signal is created in real time, signals consisting of the received signal and the multiplexed signal for each period _{qT H q + m (q-} 1) is the q + m of HG and VG screen (q-1) pieces of each of the scanning lines Parallel display in real time.

[0018]

As described above, the detection and display method of the present invention transmits to a wide three-dimensional space in the depression angle direction, performs composite scanning of the reception beam, detects in real time, and obtains a reception signal from the three-dimensional space. Since the VG screen is displayed in real time by a multiplex signal created in real time from the received signal, the VG screen is surface-scanned and displayed with a wide depression angle every transmission, the fish school image is drawn precisely, the recognition of the fish school image, It is possible to intuitively and easily discriminate the distribution situation and noise, and to prevent fatigue due to long-term observation of the screen. Therefore, it is highly useful for tracking and investigating fish schools with drastic changes in depth, density distribution and shape.

In the above description, an example of detecting the entire circumference is shown.
When the detection display method for increasing the number of azimuth scans is also used by setting the azimuth scan width of the reception beam to be appropriately narrow, the display screen can be improved together with the increase in the detection depression angle width and the detection display density.

[Brief description of the drawings]

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

FIG. 2A is a plan view showing a method for detecting the scanning sonar of FIG. 1; (B) is a longitudinal sectional view of (a). (C) is a figure which shows the display on a display of (a) and (b). (D) is a figure which shows the interpolation display by (a) and (b).

FIGS. 3A and 3B are diagrams specifically illustrating scanning control of a reception beam; FIGS. (C), (d) and (e) are illustrations of a multiplex signal formed from a received signal.

FIG. 4 is an explanatory diagram of a signal former.

FIG. 5A is a plan view showing a conventional scanning sonar detection method. (B) is a longitudinal sectional view of (a). (C) is a figure which shows the display on a display of (a) and (b). (D) is a waveform diagram showing the scanning operation according to (a) and (b).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmitter 2 Transmitter / receiver 3,4 Vertically-arranged transducer 5 Depressed angle scanner 6 Oscillator 7 Delay circuit 8 Switching matrix 9 Controller 10,11 Phase shifter 12 Azimuth scanner 13 Multiplexer circuit 14 Delay circuit 15,16,17 Signal Former 18 Display 19 Display 20 Converter 21, 22 Multiplier 23 Adder TB Transmit Beam RB Receive Beam HG Plane Screen VG Vertical Screen

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01S 15/96 G01S 7/62 G01S 15/89

Claims (3)

(57) [Claims] 1. A vertically arranged vibrator comprising a plurality of vibrators arranged on a cylindrical surface along a cylindrical axis and arranged in a plurality of rows, and the vertically arranged vibrators arranged in a plurality of rows form at least a part of the cylindrical surface. In a scanning sonar using a transducer that covers an average, a transmitting beam is transmitted with a wide angle of depression to direct the entire circumference facing the vertical arrangement, and the angle of depression of the receiving beam is predetermined for each azimuth scanning cycle. Azimuth scanning within a predetermined azimuth width, outputting azimuth scanning output, compensating for the reception time difference between azimuth scanning outputs of adjacent azimuth scanning periods, and outputting azimuth scanning A method for detecting and displaying a scanning sonar that forms an interpolated scan output for interpolating between signals, and forms and displays an image in real time using an azimuth scan output and an interpolated scan output. 2. A vertically arranged vibrator comprising a plurality of vibrators arranged on a cylindrical surface along a cylindrical axis and arranged in a plurality of rows, and the vertically arranged vibrators arranged in a plurality of rows form at least a part of the cylindrical surface. In a scanning sonar using a transducer that covers an average, a transmitting unit that transmits a transmitting beam directed to the entire circumference facing the vertical arrangement with a wide depression angle width, and a depression angle of the receiving beam is predetermined for each azimuth scanning cycle. Depression angle scanning means for repeatedly changing sequentially by a predetermined angle within a predetermined range, and azimuth scanning for azimuth scanning the azimuth of the reception beam within a predetermined azimuth width for each depression angle set by the depression angle scanning means. Means for delaying the azimuth scanning output of the azimuth scanning means by one azimuth scanning cycle and outputting the result as a delay output; and inputting the azimuth scanning output and the delay output, and azimuth scanning of adjacent azimuth scanning cycles. Signal forming means for outputting an interpolated scan output for interpolating between outputs; and image display means for forming and displaying an image in real time using the azimuth scan output and the interpolated scan output for each azimuth scan cycle. Scanning sonar. 3. The scanning sonar according to claim 2, wherein said signal forming means outputs a multiplexed signal in which the azimuth scan output and the delay output are appropriately distributed as an interpolation scan output.