JPH05288854A - Scanning sonar and its detection display method - Google Patents

Abstract

PURPOSE:To obtain a scanning sonar which can read a target to be detected from a display screen easily. CONSTITUTION:A transmitter 1 transmits a transmission beam TB which has a wide depression angle width and where vertical arrangement is directed toward opposing entire peripheries, an depression angle scanner 5 changes the depression angle of a reception beam RB for each azimuth scanning period in sequence, and then an azimuth scanner 12 performs azimuth scanning within a predetermined azimuth width and then outputs azimuth scanning output. A multiplex circuit 13 forms an interpolation scanning output for interpolating between azimuth scanning outputs of adjacent azimuth scanning periods and then forms and displays an image in real time using the azimuth scanning output and interpolation scanning output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of detecting a wide azimuth and a wide depression angle by using a transducer in which a plurality of vertically arranged oscillators in which a plurality of oscillators are vertically arranged are arranged in a plurality of columns in a cylindrical shape or an arc shape. The present invention relates to a scanning sonar that can detect and display 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 transducer 2 having a vertically-arranged transducer formed by stacking a plurality of transducers in a cylindrical shape is used and has a depression angle θ and is directed to the entire circumference. Transmit beam TB
As shown in FIGS. 5 (b), 5 (c) and 5 (d), the signal is transmitted at the depression angle θ and the entire circumference is 360 ° at a high speed in the azimuth φ direction at every azimuth scanning period T _H within the transmission period T _X. A plane signal (hereinafter referred to as HG) in which a reflection signal from a reflector such as a school of fish F (hereinafter simply referred to as a school of fish) in a depression angle θ ₁ direction (hereinafter simply referred to as a school of fish) is displayed through a reception beam RB that is rotationally scanned. PPI is displayed on the screen. Next, as for the depth display of the detected school of fish, the school of fish F on the HG screen is displayed as shown in FIG.
Each time the reception beam passes between the azimuth marks φ _{1 and} φ ₂ which are appropriately selected in the direction of FIG.
Vertical screen that is displayed vertically like below (hereinafter referred to as VG screen)
A fish school image F (average value, maximum value, etc.) is displayed on the scanning line swept in the upper depression angle θ ₁ . The depth of the school of fish is read by an appropriate depth scale not shown in the figure. Next, the detection and display of the distribution and shape of the fish school in the depth direction are performed by detecting the depression angle of the transmission beam TB and the reception beam RB and the VG.
The scanning angle (depression angle) of the scanning line on the screen is sequentially switched to proper angles θ _S, θ ₁ , θ _2, ... At the same time for each transmission cycle to perform detection and display. 5C and 5D show an example in which the fish angles F 1 and F 2 in the two depression angles are displayed by detecting the depression angles θ ₁ and θ ₂ by two transmission cycles. In this way, after a plurality of detections in the depression angle direction are performed for each transmission cycle, the distribution and shape 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. The detection display method in the case where the vertically arranged transducers of the wave transmitter / receiver are arranged in an arc shape is the same as the above except that the detection width in the azimuth direction is different from that for the entire circumference, and therefore is omitted.

[0003]

The detection and display of a three-dimensional space wide in the depression direction over the entire circumference by the conventional scanning sonar requires detection and display in a large number of depression angles, but in one transmission cycle. Since only the detection in the depression angle direction and the received image on the scanning line in the depression angle direction can be obtained, it takes time to detect and display the entire space. In addition, in order to shorten the detection time, as shown in the VG screen of FIG.
_{When S} is made larger than the receiving beam and the switching speed is increased, the blank area between scanning lines expands, and the school of fish is displayed sparsely in the depression angle direction, making it difficult to recognize the school of fish and interpret the distribution status and the school of fish. And the noise discrimination is hindered and the detection ability is reduced. Since the depression angle switching angle θ _S is made small for the above reason, there is a drawback that it takes time to detect and display the entire space. Further, in order to detect a plurality of depression angles at the same time, using a plurality of receivers for each depression angle causes a cost increase.

An object of the present invention is to detect a wide space in the depression direction over the entire circumference by switching the depression angle for each transmission cycle as described above and display one scanning line at a time. Further, if the depression angle switching angle is widened to shorten the detection time, the blank area between the scanning lines of the VG screen increases, making it difficult to observe the image, and the receiver for parallel detection in a plurality of depression angles. In the case of using a plurality of combinations, the problem of increasing the cost is omitted, and the depression beam is scanned each time the azimuth scanning of the reception beam is performed, and the entire circumference in the plurality of depression angles is sequentially and repeatedly detected, and adjacent 2 In order to interpolate between the received signals of a pair obtained by azimuth scanning of one depression angle, the received signals and the multiplexed signals are combined in real time by combining the received signals of a pair at an appropriate distribution ratio and creating an appropriate number of multiplexed signals. Can be displayed side by side It is to try to provide a canning sonar.

[0005]

According to the detection display method of the scanning sonar of the present invention, a plurality of columns of vertically arranged transducers, each of which is composed of a plurality of transducers arranged along a cylindrical axis on a cylindrical surface, are arranged. In a scanning sonar using a transducer in which the arranged vertical array transducer covers at least a part of the cylindrical surface evenly, in a wide depression angle width, the vertical array transmits a transmission beam directed to the entire circumference facing each other, For each azimuth scanning cycle, the depression angle of the reception beam is sequentially changed by a predetermined angle within a predetermined range, azimuth scanning is performed within a predetermined azimuth width, azimuth scanning output is output, and adjacent azimuth scanning cycles The interpolating scan output for compensating for the reception time difference between the azimuth scanning outputs and interpolating the scanning outputs is formed into a signal, and an image is formed and displayed in real time by using the azimuth scanning output and the interpolation scanning output.

Further, the scanning sonar of the present invention comprises a plurality of vertically arranged transducers arranged on a cylindrical surface along a cylinder axis, and a plurality of vertically arranged transducers are arranged. In a scanning sonar that uses a transducer that evenly covers at least a part of the cylindrical surface, a transmitting means that transmits a transmission beam that directs the entire circumference with a wide depression angle width,
Depression angle scanning means that repeats sequentially changing 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 means Azimuth scanning means for azimuthally scanning the inside, 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, and azimuth scanning output and delay output are input, and adjacent azimuths are inputted. A signal forming means for outputting an interpolating scan output for interpolating between azimuth scanning outputs of the scanning cycle, and an image display means for forming and displaying an image in real time by using the azimuth scanning output and the interpolating scan output for each azimuth scanning cycle. Have. Further, it is preferable that the signal forming means outputs a multiplexed signal in which the azimuth scanning output and the delay output are appropriately distributed as an interpolation scanning output.

[0007]

Since the scanning sonar of the present invention is configured as described above, the scanning sonar is provided with the depression angle scanning means while receiving the echo of the transmission beam which is transmitted by the transmission circuit for each transmission cycle and which is directed over the entire circumference with a wide depression angle width. 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 before and after, and 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 the detected image is displayed.

For example, reception as shown in FIGS. 3 (a) and 3 (b)
Beam RB (: azimuth angle φ, depression angle θ) is azimuth scanning cycle T_H
(Hereinafter simply cycle T_HWhen the whole circumference is scanned every
Anyway, the depression angle is an appropriate angle θ_S(Example: To prevent detection omission
Angle smaller than half-width half angle)₁, Θ₂, ..., θ
_qAnd the cycle qT_HDepression scan is repeated every
Multi-angle scanning is performed continuously during the transmission cycle
The whole space is detected in real time, and the received signal is real
Taken out in time. Next is the adjacent depression angle (eg, θ₁When
θ₂), The period T_HBack and forth at intervals of
As shown in Fig. 3 (c) among the two received signals
Cycle preceding (# 1T_H) In depression angle θ₁Got from
Received signal (S₂) With period T_HTaken out after a delay
Received signal S₁(Referred to as the first signal), followed by
Cycle (# 2T_H) In depression angle θ ₂Received from
Issue S₂(It is called the second signal)
Simultaneously as a pair of time-series signals that make the respective detection directions equal
Taken out. Next, as shown in Fig. 2 (c),
Depression angle θ₁And θ₂Opening angle θ_SIs appropriately divided (example: m
Depression angle δ set to +1 division)₁, Δ₂・ ・ ・
., Δ_mThe signal to be displayed on the corner scanning line of
Lower multiplexed signal) SS₁, SS₂・ ・ ・ ・ ・ ・ SS_mL
= 1, 2, ..., M, the first signal S₁And the second
Signal S₂ The following equation (1)

[0009]

[Equation 1] It is formed by allocating and combining as described below. If m = 6, the multiplexed signals SS ₁ , SS ₂ , ..., SS _m are expressed by the following equation (2).

[0010]

[Equation 2] And is output like the model of FIG. These multiple signals SS ₁ , SS ₂ , ..., SS _m
And received signals S ₁ , S ₂ and depression angles δ ₁ , δ ₂ , ..., δ _m
And the relationship between θ ₁ and θ ₂ are shown as (c), (d), and (e) in the same figure. Then, from the received signals S ₁ , S ₂ and the multiplexed signals SS ₁ , SS ₂ , ..., SS _m , the HG of FIG.
A signal between the azimuth widths φ _{1 and} φ ₂ of the screen is appropriately selected and displayed as in the VG screen of FIG. Then, as in the above, as shown in FIG. 3 (b), the depression angle scan is performed for each cycle T _H , and the depression angles are successively adjacent (eg, θ ₁ and θ ₂ , θ ₂ and θ).
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 in the figure in the receiving signal of the depression angle theta ₁ is cycle # 1T _H (c)
_It is taken out as ₂ and displayed as in the VG screen of FIG.

Since the cycle 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 for detecting a single unit is set to about 4 mS.

In this way, the three-dimensional space 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 beams, which are q circumferentially scanned in each depression direction, and are adjacent to each other. Time compensation of a pair of received signals obtained at different times from the depression angle is performed, and then combined at an appropriate allocation ratio to form m multiplexed signals, and the obtained q time-series reception from all circumferences. Signal and m (q-1)
The time-series received signals corresponding to all the circumferences are displayed on the HG screen by q + m (q-1) scanning lines, and the signals between the azimuth widths φ _{1 and} φ ₂ in the received signals and the multiplexed signals are HG. It is displayed in real time on the VG screen at the same time as the screen.

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 the detection and display method of the present invention is performed for each transmission cycle. Since the detection in the q-angle direction and the parallel image display of the scanning lines of q + m (q-1) are performed in real time to display an image without a blank portion, the detection display does not take time.

As described above, a school of fish that spreads in a three-dimensional space with a wide circumference in the depression direction is detected in real time for each transmission cycle and is displayed in real time by a large number of scanning lines on the HG and VG screens. The image can be easily recognized and the distribution situation can be easily understood, and the noise can be easily discriminated to improve the detection ability.

[0015]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the scanning sonar of the present invention.

A transmitter / receiver configured in the transmitter 1 in a conventional manner
As shown in Fig. 2 (a), a wide depression angle θ_W 
At, the transmission beam TB that directs the entire circumference is formed and transmitted.
N vertical stacks that are stacked in k stages of the transducer 2 and face the n direction
The row oscillators 3 to 4 receive the received signal S ₁₁~ S_1K・ ・ ・ ・ ・ ・ S_n1~
S_nkIs output. Angle of depression θ₁ ~ Θ_q Received in
Issue S₁₁~ S_n1Received signal S for₁₂~ S_n2・ ・ ・ ・ ・ ・ S
_1k~ S_nkEach phase difference of the
Depression angle θ of the pendulum₁ ~ Θ_q Ψ for 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_jpIs abbreviated. The oscillator 6 of the depression scanner 5 is a station
Signal L₁ Is output. The delay circuit 7 is a delay circuit with a tap
Input signal L from each tap₁ Against
Phase difference ψ_jp(: Ψ_{twenty one}~ Ψ_kq) With signal group L_G Output
To do. Switching matrix 8 is signal group L_G Input
Local output L to line and phase shifters 10-11₂ ~ L_k Output of
Electronic switch for switching connection between line and input-output line
Control circuit D for controlling the group₁~ D_q It is composed of Control
The controller 9 has a cycle # 1T as shown in FIG._H ~ #QT_H of
Cycle T_H Control line D for each₁ ~ D_q Sequentially operate each
Phase difference ψ from the input line via the switch group of the control line_{twenty one}
~ Ψ_k1・ ・ ・ ・ ・ ・ Ψ_2q~ Ψ_kqSequentially extract signals with
And the local output L of the output line₂ ~ L_k Cycle of each phase of_H 
Switch simultaneously and instantly for each. Phase shifters 10-11
As in the past, the abbreviated modulator and synthesizer
Configured, received signal S₁₁~ S_n1, S₁₂~ S_n2・ ・ ・ ・ ・ ・
S_1k~ S_nkIs the local L₁ , L₂ ~ L_k Due to
Adjust to the same phase, and then synthesize by each synthesizer
And the cycle qT_H At period T_H The depression angle is θ₁ ~
θ_q Receiving by receiving beam pointing in n direction
Signal S_V1~ S_VnIs output. Then instantly as above
The depression angle scan that can be switched is the cycle qT._H Every real time
It repeats at and continues. Direction scanner 12 inputs in parallel
Received signal S from n direction_V1~ S_VnAs appropriate as before
Select it, take it out, and phase it.
Of horizontal directivity of reception beam RB and period T_H Every
Azimuth scanning of the entire circumference of the received signal S₂ In real time
Output. In this way, as shown in Fig. 3 (a) and (b)
Cycle qT _H Depression angle θ₁ ~ Θ_q All around each direction
The detection is sequentially repeated in real time, and the received signal is
It is output in real time. The multiplexing circuit 13 receives the input signal S₂ 
The delay circuit 14_H Delay time equivalent to
Signal S of 1₁ Output as. Then the first signal S₁ When
Signal S input in real time₂ (The second signal
U) is input to m signal shapers (1 to m) 15 to 17.
Be done. The signal formers (1 to m) 15 to 17 are as described above and
2 (d), the depression angle switching angle θ as shown in FIG. 3 (e)_SM + 1
Dividing angle δ₁ , Δ₂ ・ ・ ・ ・ ・ ・ Δ_m Table on the scan line
Show multiple signal SS₁ , SS₂ ・ ・ ・ ・ ・ ・ SS_m Formation of
Each circuit is configured as shown in FIG. Each signal formation
The multipliers 21 and 22 of the units 15 to 17 are the above formula (1).
The first and second terms of
The calculator 23 adds the outputs of the multipliers 21 and 22 and multiplexes them.
Signal SS_L(L = 1,2, ..., m) is output. these
The multiplexed signal has a period T as shown in FIGS._H For each
Created between depression angles and the cycle qT_H It is repeated every time.
The converter 20 of the display 18 has a scan converter or the like.
Then, the multiplexed signal SS from the multiplexing circuit 13_L And received signal
S₂ For color cathode-ray tube display for TV
2C of the display screen of the display unit 18 having a display device.
Such as the HG screen and the multiple signal SS_L When
Received signal S₂Direction mark φ on the HG screen from inside₁~ Φ₂ 
The signal between the two is taken out, and the VG screen of FIG.
Angle δ₁ ~ Δ_m And θ₂ Real time on each scan line
To display the image.

As described above, during the transmission cycle, the cycle qT
The entire circumference detection for each q depression angle direction is repeated for each _H by compound scanning, the time-series received signals of the entire circumference for each q depression angle direction are sequentially extracted in real time, and the cycle T _{H is} calculated for each adjacent depression angle.
M from the time series signals 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 It is displayed side by side in real time.

[0018]

As described above, the detection and display method of the present invention transmits signals to a wide three-dimensional space in the depression angle direction, performs complex scanning with a reception beam to detect in real time, and obtains a received signal from the three-dimensional space. And, since the VG screen is displayed in real time by the multiplex signal created in real time from the received signal, the VG screen is surface-scanned and displayed with a wide depression angle width for each transmission, and the fish school image is drawn finely to recognize the fish school image. The distribution status and noise can be discriminated intuitively and easily, and fatigue due to long-term observation of the screen can be prevented. Therefore, it has a high utility value for tracking and surveying a school of fish with drastic changes in depth, density distribution, and shape.

Further, although the above has shown an example of detecting the entire circumference,
When the detection display method for increasing the number of azimuth scannings is used together by appropriately setting the azimuth scanning width of the reception beam, the detection depression angle width and the detection display density can be increased and the display screen can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a scanning sonar according to the present invention.

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

FIG. 3A and FIG. 3B are diagrams for specifically explaining scanning control of a reception beam. (C), (d) and (e) are explanatory views of a multiplexed 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 method for detecting a scanning sonar. (B) is a longitudinal sectional view of (a). (C) is a figure which shows the display on the display of (a) and (b). (D) is a waveform diagram showing the scanning operation according to (a) and (b).

[Explanation of symbols]

 1 transmitter 2 wave transmitter / receiver 3,4 vertical array transducer 5 depression angle scanner 6 oscillator 7 delay circuit 8 switching matrix 9 controller 10, 11 phase shifter 12 azimuth scanner 13 multiplex circuit 14 delay circuit 15, 16, 17 Signal forming device 18 Display device 19 Display unit 20 Converter 21,22 Multiplier 23 Adder TB Transmit beam RB Receive beam HG Flat screen VG Vertical screen

Claims (3)

[Claims] 1. A vertical array vibrator comprising a plurality of vibrators arranged on a cylindrical surface along a cylinder axis is arranged in a plurality of rows, and the vertically arranged vibrators arranged in a plurality of rows cover at least a part of the cylindrical surface. In a scanning sonar that uses a transducer that covers evenly, it transmits a transmission beam that has a wide depression angle and directs the entire circumference facing the vertical array, and the depression angle of the reception beam is set in a predetermined range for each azimuth scanning period. Within a predetermined azimuth width, azimuth scanning is performed within a predetermined azimuth width, azimuth scanning output is output, and the azimuth scanning output is compensated for the reception time difference between azimuth scanning outputs of adjacent azimuth scanning cycles. A detection and display method for a scanning sonar, which forms an interpolated scan output for interpolating a signal and forms and displays an image in real time using the azimuth scan output and the interpolated scan output. 2. A vertical array transducer comprising a plurality of vibrators arranged on a cylindrical surface along a cylindrical axis is arranged in a plurality of rows, and the vertically arranged vibrators arranged in a plurality of rows cover at least a part of the cylindrical surface. In a scanning sonar that uses a transducer that covers evenly, in a wide depression angle width, a transmitting means that transmits a transmission beam that directs the entire circumference facing the vertical array, and the depression angle of the reception beam is determined in advance for each azimuth scanning cycle. Depression angle scanning means that repeats sequentially changing only a predetermined angle within a predetermined range, and azimuth scanning that azimuthally scans the azimuth of the reception beam within a predetermined azimuth width for each depression angle set by the depression angle scanning means. Means, delay means for giving a delay for one azimuth scanning cycle to the azimuth scanning output of the azimuth scanning means, and outputting as a delay output, and azimuth scanning output and delay output for inputting azimuth scanning of adjacent azimuth scanning cycles. A signal forming means for outputting an interpolation scan output for interpolating between outputs, and an image display means for forming and displaying an image in real time using the azimuth scan output and the interpolation scan output for each azimuth scan cycle. Scanning sonar. 3. The scanning sonar according to claim 2, wherein the signal forming means outputs a multiplexed signal in which the azimuth scanning output and the delay output are appropriately distributed as an interpolation scanning output.