JPH0719020Y2 - Target tracking system scanning sonar - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an improvement of a scanning sonar equipped with a means for tracking a target such as a school of fish.

(Prior art) An ultrasonic wave transmitter / receiver installed on the bottom of a ship, etc. emits an ultrasonic beam toward a target such as a school of fish, processes echo signals from the target, and displays a target detection image on a color CRT display. Scanning sonars are well known. In recent years, this type of device is provided with a depression angle tracking means for changing the depression angle of an ultrasonic beam by following the movement of a target.

This depression angle tracking means attaches a target mark to the target position of the target detection image at a certain time point obtained from the echo, that is, an event mark is added, and the event mark is correct with respect to the hull according to the navigation amount and the navigation direction of the hull. The relative position is obtained by calculation, etc., and the depression angle of the ultrasonic beam is changed by following the relative movement of the event mark with respect to the hull. That is, the aim is to track the target by always directing the depression angle of the ultrasonic beam toward the event mark.

(Problems to be Solved by the Invention) In the above-mentioned conventional apparatus, when the target is a stationary body, the target and the event mark are always integrated, so that if the depression angle of the ultrasonic beam is directed toward the event mark, it will be long. Track time targets without losing sight. However, when the target is a moving object such as a school of fish, the target will move from the event mark over time, so
There is the inconvenience of losing sight of the target even if the depression angle is directed toward the event mark. Therefore, when using the conventional device, the operator had to recapture the target at regular intervals and re-attach the event mark to the captured target.

The present invention has been made to solve the above conventional problems, and its purpose is to track the position of an event mark to the movement of a target even if the target is a moving object such as a school of fish. The present invention is to provide a scanning sonar of a target tracking system that can be automatically corrected by the above method.

(Means for Solving Problems) The present invention is configured as follows to achieve the above object. That is, the present invention comprises a main storage unit for storing a target detection signal obtained by an ultrasonic wave transmitter / receiver mounted on a hull; and a display device for reading the information in the main storage unit and displaying the image of the target detection signal. In the target tracking type scanning sonar provided, a marker area setting section that marks a target position in the main memory section and variably sets a tracking detection area in a predetermined range centered on the mark; A gate circuit that takes in only the signal of the tracking detection region among the target detection signals read from the main storage unit by the region setting signal; an auxiliary storage unit that stores the target detection signal of the tracking detection region added from the gate circuit; The pixel information in the auxiliary storage unit is read, the storage pixel position having the highest target level is detected by the comparison calculation of the signal level of the pixel information, and the detection signal is obtained. A scanning Sohna target tracking scheme with; and level comparison determination circuit is added to the marker area setting unit as a correction signal over click position.

(Operation) In the present invention having the above configuration, target tracking is performed as follows. First, while looking at the target detection image displayed on the display device, a target mark, for example, an event mark is put on the target by a known means. That is, this event mark is attached to the target storage pixel (pixel storing the target) among the pixels in the main storage unit. On the other hand, the marker area setting unit sets a tracking detection area in a predetermined range around the event mark in the main storage unit. Then, the stored information of the tracking detection area is, for example,
The data is read out to the auxiliary storage unit via the gate circuit for each ultrasonic wave transmission / reception cycle.

The level comparison determination circuit reads out the signal of the tracking detection area stored in the auxiliary storage unit, and the storage pixel position having the highest target level is set in the tracking detection area by the comparison operation of the signal level of the pixel information. The target position is detected and this target position information is added as a correction signal to the marker area setting unit. The marker area setting unit receives the correction signal, changes the event mark from the previously set target position to the newly detected target position, and sets a new tracking detection area centered on the changed event mark. To do. Then, the old tracking detection area is updated to the new tracking detection area. Thus, by repeating the detection of the target position and the correction of the event mark position and the update of the tracking detection region at every ultrasonic wave transmission / reception cycle or at constant time intervals, the event mark can be matched with the target position. . Therefore, by following the movement of the event mark, the moving target can be captured on the display screen without losing sight of it.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment according to the present invention. In the figure, the device of the present embodiment includes a transmission / reception unit 1, a coordinate conversion circuit 2, a main storage unit 3, a display device 4, a marker area setting unit 5, an auxiliary storage unit 16, and a level comparison / determination circuit 17. And the write / read control circuit 7,
It has a timing controller 8 for outputting a timing signal and an operation controller 9.

The transmission / reception unit 1 receives a timing signal from the timing controller 8 and issues an ultrasonic wave transmission / reception command to an ultrasonic wave transmitter / receiver (not shown) mounted on a ship bottom or the like. The ultrasonic wave transmitter / receiver emits ultrasonic waves toward a designated depression angle, that is, a target such as a school of fish, in accordance with a transmission / reception command of the transmission / reception unit 1,
Receive echo from target. Then, the received signal is converted from a sound wave signal into a reception signal as an electric signal, and the analog reception signal is further converted into a digital signal and subjected to predetermined signal processing such as amplification and the like as a signal in a spiral scan polar coordinate system. It is sent to the conversion circuit 2. The coordinate conversion circuit 2 converts the signal in the polar coordinate system into a signal in the orthogonal coordinate system for raster scanning, and adds the converted signal to the main storage unit 3.

The main memory unit 3 has a memory element composed of a pixel array corresponding to the pixels of the color CRT display 10 in a one-to-one relationship.
The signal sent from the coordinate conversion circuit 2 is written and stored in the storage element as a target detection signal.

By the way, the display device 4 includes a D / A converter 11, a color CRT display 10, and a sweep circuit 12. D / A converter 1
Reference numeral 1 converts the digital target detection signal read from the main storage unit 3 into an analog target detection signal, and further performs coloring according to the signal level.

The coloring of this signal is performed, for example, by using a combination of the three primary colors of the color signal and changing the ratio of the combination according to the signal strength. This colored target detection signal is applied to the color cathode ray tube display 10. .

The sweep circuit 12 sweeps the screen of the color cathode ray tube display 10 to specify the display device of the target detection signal applied from the D / A converter 11.

A color image of the target detection signal is displayed on the screen of the color cathode-ray tube display 10 by this continuous position designation, that is, sweeping.

The coordinate conversion operation of the coordinate conversion circuit 2, the writing / reading operation of the main storage unit 3, and the sweeping operation of the sweep circuit 12 are performed by operation signals applied from the write / read control circuit 7, and the timing of each operation. Is performed in synchronization with the scanning timing of the raster scan of the coordinate conversion circuit 2 by the timing signal applied from the timing controller 8.

On the other hand, as shown in FIG. 2, the marker region setting unit 5 displays the display image of the target detection signal, that is, the target A of the target detection image.
The tracking detection area 14 is set in a predetermined range centered on the mark, that is, the event mark 13, placed on the top. In this case, first of all, the color CRT display 10
The event mark 13 is attached to the target A on the target detection image of the above using a known means (not shown), for example, a joystick or the like. Event mark 13 by this well-known means
Is input to the marker area setting unit 5 from the operation controller 9 via the level comparison / determination circuit 17. The marker area setting unit 5 receives the input signal of the event mark 13 and sets a tracking detection area within a predetermined range around the event mark 13.
14 is set, and the area setting signal is added to the main memory unit 3 and the gate circuit 15.

In response to the area setting signal, in the main memory 3, the event mark 13 is provided at the target pixel position of the target detection image (the target memory pixel position of the main memory 3 corresponding to the target display pixel position of the color CRT display 10). The tracking detection area 14 centered on the event mark 13 is stored. In this way, the event mark 13 and the tracking detection area 14 centered on the event mark 13 are set on the target detection image in the main storage unit 3.

The gate circuit 15 receives the area setting signal from the marker area setting unit 5 and the target detection signal of the next cycle which is read by branching from the main storage unit 3 to the D / A converter 11 (after setting the input of the event mark 13, The target detection signal obtained by the next ultrasonic transmission / reception) and the tracking detection area 4 within the target detection signal 1
Only the signal of is added to the auxiliary storage unit 16.

The auxiliary storage unit 16 stores the signal of the tracking detection area 14 and reads the stored signal to the level comparison / determination circuit 17. The level comparison / judgment circuit 17 compares the levels of the signals read from the auxiliary storage unit 16 and calculates the pixel having the highest signal level in the tracking detection area 14 (the pixel at the center position having the highest signal level). Is detected as a target memory pixel (target memory position).

For example, as shown in FIG. 3, when each pixel of the tracking detection area 14 has an array of 7 columns from X ₀ to X _{6 in the} horizontal direction and 7 rows from Y ₀ to Y _{6 in the} vertical direction, Pixel signal level strength is 0
Numerical values from 1 to 9 (the higher the value, the higher the signal level). The level comparison / determination circuit 17 starts from the X ₀ column to X ₆
The level values of each pixel are added for each column up to the column, and the column with the largest added value, column X _{4 in the} figure, is found from the comparison of the added values.

Similarly, the column Y _{1 is found} as the column with the maximum added value by comparing the added values of columns Y ₀ to Y ₆ .

Then, the level comparison / determination circuit 17 determines the pixel at the position (X ₄ , Y ₁ ) where the X ₄ column and the Y ₁ column where the added value is maximum intersect, as the target storage pixel. In this case, for example, if the event mark 13 attached one cycle before is at the pixel position of (X ₃ , Y ₃ ), the target A will be (X ₃ ,
The position S of Y ₃ ) is moved to the position S ′ of (X ₄ , Y ₁ ), and the position S of the first event mark 13 and the position of the target A ′ after the movement are displaced.

The level comparison / determination circuit 17 uses the detection signal of the newly determined target storage position (X ₄ , Y ₁ ) as a correction signal for the operation controller 9
And to the marker area setting unit 5. Upon receiving the correction signal, the marker area setting unit 5 changes the event mark from the position (X ₃ , Y ₃ ) to a new target storage position (X ₄ , Y ₁ ) and changes the target A'and the event mark 13 '. And a new tracking detection area 14 ′ (not shown) is set around the position of (X ₄ , Y ₁ ) as a center, and the old tracking detection area 14 provided in the main storage unit 3 is updated. The tracking detection area 14 'is updated.

According to the present embodiment, the level comparison / determination circuit 17 detects the target position and outputs the correction signal, and the marker area setting unit 5 replaces the event marks 13 and 13 'and the tracking detection areas 14 and 14 respectively. As a result of the updating of ′ every cycle or every predetermined time interval, it becomes possible to cause the event marks 13 and 13 ′ to follow the moving target A and the same A ′ without deviation, and to check this event mark. It is possible to readjust the depression angle of the ultrasonic beam according to the movement of the target without losing sight of the moving target.

By the way, shaking of the hull, bubbles in the water, floating materials such as dust,
In rare cases, it may not be possible to correctly capture the target position due to sudden temperature changes or other severe changes in ultrasonic wave propagation conditions. In such a case, the tracking purpose of the depression angle cannot be sufficiently achieved by the automatic tracking method.

In the present embodiment, in consideration of such an abnormal situation, the automatic tracking method of the depression angle and the conventional depression angle tracking method can be switched and used.

In the present embodiment, hull navigation information such as ship speed information and hull movement direction (navigation direction) information is added to the motion controller 9, and the motion controller 9 is moving the hull based on this hull navigation information. , The correct relative position of the stationary target with respect to the hull is calculated, and the calculated position is added to the level comparison / determination circuit 17.

Then, the information on the calculated position is further added to the marker area setting unit 5 as a correction signal.

Since the marker area setting unit 5 repositions the event mark 13 at the calculation position sent at a constant time interval, the event mark 13 attached to the stationary target is changed in accordance with the movement of the hull as in the conventional method. It can be displayed in a position that maintains the correct relative position with the hull. Since the information on the calculated position of the stationary target calculated by the motion controller 9 is added to the transmitting / receiving unit 1 as a depression angle change command, the depression angle of the ultrasonic beam is determined by the event mark 13, that is,
It will be controlled to face the stationary target.

The changeover between the automatic tracking method of these depression angles and the conventional method is performed by a changeover switch. When the position is abnormally distant, it is detected as an abnormal situation of the ultrasonic wave propagation condition, and the changeover switch is operated to switch the depression angle control to the conventional method, and after a lapse of a predetermined time, the abnormality of the ultrasonic wave propagation condition is resolved. It is configured to switch to the automatic tracking method again.

(Effect of the Invention) Since the present invention has the configuration and operation as described above, even when the target is a moving object such as a school of fish, it is possible to change the event mark on the moving target. This makes it possible to readjust the depression angle of the ultrasonic beam according to the movement of the target without losing sight of the moving target.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment according to the present invention, FIG. 2 is a mode diagram of image display of a target detection signal, and FIG. 3 is a storage state diagram of a signal level in a tracking detection area. 1 ... Transmitting / receiving unit, 2 ... Coordinate conversion circuit, 3 ... Main storage unit, 4 ... Display device, 5 ... Marker area setting unit, 7 ...
Writing / reading control circuit, 8 ... Timing controller, 9 ... Operation controller, 10 ... Color CRT display, 11 ... D / A converter, 12 ... Sweep circuit, 13, 13 '...
Event mark, 14, 14 '... Tracking detection area, 15 ... Gate circuit, 16 ... Auxiliary storage unit, 17 ... Level comparison / determination circuit, A, A' ... Target, S, S '... Target position.

Claims (1)

[Scope of utility model registration request] 1. A main storage unit for storing a target detection signal obtained by an ultrasonic wave transmitter / receiver mounted on a hull; and a display device for reading out the information in the main storage unit and displaying an image of the target detection signal; And a marker area setting section for variably setting a tracking detection area in a predetermined range centered on the mark at the target position of the main storage section in the target tracking type scanning sonar; A gate circuit that takes in only the signal of the tracking detection region among the target detection signals read from the main storage unit by the region setting signal from; and an auxiliary storage unit that stores the target detection signal of the tracking detection region added from the gate circuit. The pixel information in the auxiliary storage unit is read out, the storage pixel position having the highest target level is detected by the comparison operation of the signal level of the pixel information, and the detection signal is marked. A level comparing and determining circuit is added to the marker area setting unit as a correction signal of the position;
A tracking sonar using a target tracking method. _