JP5322619B2 - Scanning sonar device - Google Patents

Description

  The present invention relates to a scanning sonar device, and mainly to a scanning sonar device that automatically tracks a set target.

  Conventionally, in a scanning sonar device used for fishing or the like, for example, as shown in FIG. 4, a transmitter / receiver 40 provided in a hull or the like and located in water has a constant frequency, for example, a frequency between 20 kHz and 300 kHz. Sound waves are transmitted from the sea surface set by the user to an angle of θ (referred to as depression), and information (sampling values) based on the intensity of received echoes (reflected waves) is converted into an image and displayed.

  Here, as shown in FIG. 4, the transmitter / receiver 40 generates a pencil-shaped received beam P having directivity for receiving reflected waves from a narrow range with respect to a direction perpendicular to the sea surface (z-axis direction). Rotate clockwise or counterclockwise to receive reflected waves from 360 degrees around the circumference and scan the umbrella-shaped surface of the cone. Information based on the intensity distribution of the received reflected wave displays a target school of fish on the display device according to the distance from the transmitter / receiver (Patent Document 1).

In addition, a scanning sonar device that searches and tracks a school of fish extracts a target school of fish from information based on the intensity of reflected waves, and displays a target image T as a target image T as shown in FIG. As an image. Here, FIGS. 5 (a) and 5 (b) show the transducer 40 on the surface of the cone having a depression angle θ with respect to any direction from the center to the periphery in both the vertical and horizontal directions. The distance from is shown.
Furthermore, features such as the position of the target image are detected and stored, and based on these stored features, the target image is extracted from information based on the intensity of the reflected wave in the next transmission.

The above-mentioned scanning sonar device displays the target image on the display device when the distance from the transducer to the nearest point of the target image is the near end and the distance from the transducer to the farthest point of the target image is the far end. When the distance to the far end of the target image (hereinafter referred to as the far end distance) exceeds a predetermined reference range corresponding to the search range (search range) by the reflected wave, the search distance is set. If the distance to the near end of the target image (hereinafter referred to as the near end distance) approaches beyond the reference range, the search range is shortened and the search range is reduced. Processing is in progress. Here, the reference range is a distance range suitable for tracking and displaying the fish school surrounded by the reference distance, and the reference distance is a threshold value for changing the search range according to the movement of the fish school, By changing the search range in accordance with the movement of the school of fish, the target image of the school of fish is always displayed on the display device.
JP 2008-203227 A

However, the reference range is set by the far threshold F (F = fR, f (0 <f ≦ 1)) and the near threshold N (N = nR, n (0 ≦ n <1)) as a reference for changing the search range R. When the distance A from the transducer to the far end of the target image is set to the distance B from the near end, the target image (A, B) is expressed as F>A> B as shown in FIG. When displaying satisfying> N, there are the following problems.
The scanning sonar device reduces the exploration range R when B ≦ N is satisfied by the spread of the fish school after the far end distance exceeds the reference range due to the movement of the fish school and A ≧ F and the exploration range is expanded. In this state, as shown in FIG. 5B, the target image becomes larger with respect to the search range R, and A ≧ F and B ≦ N, and there are a condition for expanding the search range R and a condition for reducing it. The conflicting conditions will be met.
In general, in such a situation, the operation for expanding the search range is performed with priority given to the condition for expanding the search range R. However, in the operation after the search range R is expanded, B ≦ N, and the search range R is The conditions for reduction are satisfied, and the search range R is repeatedly enlarged and reduced.

  FIG. 6 is an example of an image displayed on the display device before and after the change of the search range R when the target image exceeds the reference range. As shown in FIG. 6A, when A ≧ F is satisfied, when the scanning sonar device expands the search range R by increasing the search distance by e (e> 1), the search range eR, the far threshold eF, The neighborhood threshold eN is set as each new value. However, as shown in FIG. 6B, B ≦ eN, and the condition for reducing the search range R may be satisfied. As in the case described above, the scanning sonar device repeatedly performs the expansion and reduction of the search range R.

Further, as shown in FIG. 6C, when B ≦ N is satisfied, when the scanning sonar apparatus reduces the search range R by increasing the search distance by 1 / c (c> 1), the search range R / c, the far threshold F / c, and the neighborhood threshold N / c are set as new values. However, as shown in FIG. 6D, A ≧ F / c, and the condition for expanding the search range R may be satisfied. In this case, as in the case described above, the scanning sonar device repeats the expansion and reduction of the search range R.
As described above, the scanning sonar device repeatedly enlarges and reduces the search range, the target image displayed on the display device is not stable, and there is a problem that it is difficult for the user to recognize the distance to the school of fish.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a scanning sonar apparatus that prevents frequent switching of the search range due to movement of the target image, tracks the target, and displays the target image. There is.

In order to solve the above-described problem, the present invention represents the target from a plurality of sampling values corresponding to the intensity of the reflected wave obtained by transmitting the sound wave from the transmitter / receiver to the target and receiving the reflected wave. A target image extraction unit that extracts a target image, and a target image distance calculation unit that calculates a far-end distance that is a distance from the transducer to the farthest part of the target from the target image extracted by the target image extraction unit And a search range calculation unit that changes a search range by the sound wave according to the far-end distance calculated by the target image distance calculation unit , the search range calculation unit expanding the search range? A scanning sonar device that stores a remote threshold value indicating whether or not and a near threshold value indicating whether or not to reduce the search range .

  Further, in the present invention described above, when the search range calculation unit changes the search range, the search range is such that the far end distance is an intermediate value between the far threshold and the neighborhood threshold. Is set as a new search range.

  Further, the present invention is the invention described in the above, wherein when the search range calculation unit changes the search range, the estimated far end distance estimated from the history of the far end distance is calculated as follows: The search range that is an intermediate value with respect to a threshold value is set as a new search range.

  According to this invention, the scanning sonar device is configured to change the search range according to the far end distance of the target image. As a result, the search range can be changed more stably and the search range is changed according to the far end distance than when the search range is determined using both the near end distance and the far end distance of the target image. Thus, since the target can be included in the search range, the entire target image can always be displayed.

  Hereinafter, a scanning sonar apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic block diagram showing a configuration of a scanning sonar device 1 in the present embodiment. Hereinafter, the case where the scanning sonar apparatus 1 is used for fishing with a fish school as a target will be described as an example.
The scanning sonar device 1 includes an input device 10, an operation control unit 20, a target tracking control unit 30, a transducer 40, a display information conversion unit 50, and a display device 60.
The input device 10 can be input to the scanning sonar device 1 by a user's operation, for example, a keyboard, a mouse, a trackball, or the like. The operation control unit 20 outputs information input from the input device 10 to the target tracking control unit 30 and the display information conversion unit 50. Here, information input from the input device 10 includes operation start information indicating the start of tracking of the target with respect to the scanning sonar device 1, depression information indicating the depression angle at which a sound wave is transmitted, and exploration range information for scanning the target. , Target (fish school) setting information, information indicating the search range displayed on the display device 60, and the like.

  The target tracking control unit 30 includes an exploration range setting unit 31, a target image extraction unit 32, a target image distance calculation unit 33, and an exploration range calculation unit 34, and starts operation from the operation control unit 20 indicating operation start. When the information is input, the operation is started, and the tracking processing of the fish school (target) is started by using the target setting information, the depression angle information, and the information indicating the search range input from the operation control unit 20 as initial values. In addition, the target tracking control unit 30 outputs data including the distance to the target to the transmitter / receiver 40 and receives a plurality of sampling values obtained by receiving reflected waves (echoes) from the transmitter / receiver 40. The Here, the sampling value is a value based on the intensity of the reflected wave reflected by the school of fish.

The search range setting unit 31 sets the search range output by the operation control unit 20 as the initial value of the search range at the start of the tracking operation and outputs it to the transducer 40. During the tracking operation, the search range calculation unit 34 Is set as a new search range and output to the transmitter / receiver 40.
The target image extraction unit 32 extracts, as a target image, a region constituted by a sampling value exceeding the threshold value for each frame with reference to a threshold value specified by the user input via the operation control unit 20. The information is output to the target image distance calculation unit 33 and the display information conversion unit 50. Here, the threshold value designated by the user is a value determined for each fish species or the exploration environment to be fished, and is determined based on the experience of the user. Further, a sampling value over the entire search distance for one round from 0 ° to 360 ° with respect to the angle φ shown in FIG. 4 is referred to as one frame.

The target image distance calculation unit 33 calculates the distance (far end distance A) from the transducer 40 to the farthest part of the target from the target image extracted by the target image extraction unit 32 and outputs the distance to the search range calculation unit 34. .
The search range calculation unit 34 calculates a new search range R from the set search range R and the far end distance A output from the target image distance calculation unit 33, and sets the calculated search range to the search range setting unit 31. Output to. Further, the search range calculation unit 34 stores in advance the coefficients f and n for calculating the far threshold F and the neighborhood threshold N representing the reference range for switching the search range R (where F = fR, N = nR, 0 <n <f ≦ 1).

The wave transmitter / receiver 40 includes a wave transmitter 41 and a wave receiver 42. In accordance with the depression angle and the exploration range input from the exploration range setting section 31, the wave transmission section 41 transmits sound waves in the direction of the depression angle according to the exploration range R in the direction of 360 degrees around, ie, illustrated in FIG. The sound wave is transmitted in the direction of the surface of the cone. The wave receiving unit 42 receives the reflection of the transmitted sound wave reflected by the fish school, and outputs a sampling value based on the intensity of the received reflected wave to the target tracking control unit 30.
Further, as shown in FIG. 4, the wave receiving unit 42 rotates a pencil-shaped wave receiving beam P having directivity for receiving reflection from a narrow range clockwise or in the direction perpendicular to the sea surface (z-axis direction) or Rotate counterclockwise to receive reflected waves.

  Further, the transducer 40 is installed on the bottom of a fishing boat or connected to a buoy or the like and installed in the sea (underwater). Here, the depression angle is an angle represented by an angle θ with respect to the sea surface (water surface) as shown in FIG. 4. The transmission interval is determined based on the speed of sound in water (about 1500 meters per second). For example, in the case of 1500 meters to the target, the time required for the sound wave to propagate from the transmission unit 41 to the school of fish and the reception unit from the school of fish When searching in the range centered on the fish school, about 2 seconds combined with the time required for propagation up to 42, the time depends on the distance to the fish school and the search range.

The display information conversion unit 50 converts the target image output from the target image extraction unit 32 into image information for display on the display device 60 frame by frame and outputs the image information to the display device 60. At this time, the display information conversion unit 50 may display the target image of the fish school in a color that can be easily recognized.
The display device 60 is, for example, a CRT (Cathode Ray Tube) or a liquid crystal display device, and displays and outputs the image information output by the display information conversion unit 50.

Next, FIG. 2 is a flowchart showing the operation of the scanning sonar device 1 in the present embodiment.
First, in the scanning sonar device 1, the input device 10 includes an operation start information indicating the start of fish school tracking by a user's operation, search range information indicating a search depression angle and a search range, and a target image extraction unit 32 as a target. The initial extraction area information including the threshold value used when extracting is input.
The operation control unit 20 outputs the initial extraction area information input to the input device 10 to the target tracking control unit 30 and the display information conversion unit 50. The search range setting unit 31 stores the search range information input from the operation control unit 20 and outputs the search range information to the transducer 40 (step S101).

Subsequently, the operation control unit 20 determines whether or not information indicating that tracking is stopped is input from the input device 10 (step S102).
When the information indicating the tracking stop is input (step S102: Yes), the scanning sonar device 1 stops the tracking operation.
When the information indicating the tracking stop is not input (step S102: No), the transmitter / receiver 40 transmits a sound wave and receives a reflected wave according to the search range information output by the search range setting unit 31. Then, the sampling value is output to the target image extraction unit 32 (step S103).

The target image extraction unit 32 extracts a target image for each frame from the sampling value output by the transceiver 40, and outputs the extracted target image to the target image distance calculation unit 33 and the display information conversion unit 50 (step). S104).
The target image distance calculation unit 33 calculates the far end distance A from the target image output by the target image extraction unit 32 and outputs it to the search range calculation unit 34 (step S105).
The search range calculation unit 34 determines whether the far end distance A output from the target image distance calculation unit 33 is equal to or greater than a predetermined far threshold F (step S106).

When the far end distance A is greater than or equal to the far threshold F (step S106: Yes), the search range calculation unit 34 calculates a new search range R to expand the search range, and searches the calculated new search range R. The search range R output to the range setting unit 31 and stored in the search range setting unit 31 is updated (step S107).
When the far end distance A is less than the far threshold F (step S106: No), the search range calculation unit 34 determines whether the far end distance A is less than the neighborhood threshold N (step S108).

When the far-end distance A is less than the proximity threshold N (step S108: Yes), the search range calculation unit 34 calculates a new search range R to reduce the search range, and uses the calculated new search range R as the search range. The search range R output to the setting unit 31 and stored in the search range setting unit 31 is updated (step S109).
When the far end distance A is equal to or greater than the neighborhood threshold N (step S108: No), the process returns to step S102, and thereafter, the operations from step S102 to step S109 are repeated.

Next, a method by which the search range calculation unit 34 calculates a new search range R will be described. FIG. 3 is an example of an image displayed by the display device before and after updating the search range R when the target image in the present embodiment exceeds the reference range.
First, as shown in FIG. 3A, the case where the far end distance A in step S107 is greater than or equal to the far threshold F (A ≧ F) will be described. The search range R is expanded so that the far end distance A is between the far threshold F and the neighborhood threshold N, that is, N <A <F. For example, when the far end distance A exceeds the far threshold F, if the far end distance A and the far threshold F are close to each other, an expansion coefficient e (e ≧ 1) that is an intermediate value between the far threshold eF and the near threshold eN. ) And a new search range eR shown in FIG. 3B is calculated as follows.

A≈F = (eF + eN) / 2 = e (F + N) / 2
e = F / ((F + N) / 2) = f / ((f + n) / 2),
eR = R · f / ((f + n) / 2) = F / ((f + n) / 2)

  Next, as shown in FIG. 3C, the case where the far end distance A in step S109 is less than the neighborhood threshold N (A <N) will be described. Also in this case, as in the case described above, the search range R is reduced so that the far end distance A is between the far threshold value F and the near threshold value N, that is, N <A <F. For example, when the far-end distance A is less than the neighborhood distance N, if the far-end distance A and the neighborhood threshold N are close to each other, the reduction coefficient c is an intermediate value between the far-field threshold F / c and the neighborhood threshold N / c. (C ≧ 1) is calculated, and a new search range R / c illustrated in FIG. 3D is calculated as follows.

A≈N = (F / c + N / c) / 2 = (1 / c) · (F + N) / 2
1 / c = N / ((F + N) / 2) = n / ((f + n) / 2),
R / c = R · n / ((f + n) / 2) = N / ((f + n) / 2)

  In the explanation of the calculation method of the new search range, the far end distance A and the far threshold value F or the far end distance A and the near threshold value N are treated as close values. In this situation, since the search is always performed, even if the far end distance A goes out of the reference range, it is unlikely that the far threshold value F or the near threshold value N is far away. Even if the calculation process is simplified, the target image can be kept within the search range.

  As described above, the exploration range calculation unit frequently sets the exploration range R as the new exploration range by setting an intermediate value (1/2 value) between the distant threshold value and the near threshold value as the target image moves. Can be prevented, and a stable target image can be displayed, and the entire target image can always be displayed. Further, the scanning sonar device 1 determines whether or not the search range R is changed only by the far end distance A when the search range R is updated, so that the search range R is determined by the far end distance A and the near end distance B. Compared with determining the change, the processing can be simplified and the amount of calculation can be reduced.

  Further, since the search range R is not frequently changed, the transmission interval in the transmitter / receiver 40 is not frequently changed, and the sampling can be stably performed, so that the target can be tracked stably. Further, in order to track the target, the target can be accurately grasped as the target is always within the search range and the number of searches within a certain period is large. Since the scanning sonar device 1 of the present embodiment satisfies the above-described conditions, the target can be tracked efficiently by accurately capturing the target.

The search range calculation unit 34 sets the new search range R to the far end distance A, which is an intermediate value (1/2) between the far threshold F and the neighborhood threshold N. It is good also as a different value according to the moving speed of the fish made into the object of fishing when it goes away or approaches.
The search range calculation unit 34 may use the estimated far end distance A ′ of the target image estimated from the history of the far end distance A, instead of using the far end distance A for the determination of changing the search range R. Thereby, when the transmitter / receiver 40 and the school of fish approach or leave monotonously, the search range R can be changed in advance, and the target image can be displayed stably even if the school of fish is moving. It is possible to prevent frequent changes in the display image due to range switching, and to make the user easily recognize the position and movement of the school of fish.

  Further, the search range calculation unit 34 may select a new search range as a new search range R from a plurality of predetermined search ranges, for example, 200 m, 500 m, 1000 m, 1500 m, and 2000 m. . At this time, a plurality of predetermined search ranges are input from the input device 10 by the user and stored in the search range calculation unit 34 via the operation control unit 20. Thus, for example, by selecting a search range R that is frequently used by the user or a search range R that is easy for the user to recognize, the user can easily recognize the position of the school of fish. Can do.

The coefficients f and n for calculating the reference range are determined according to the moving speed of the fish species to be searched and the search environment.
Further, although the extraction of the target image is performed based on the threshold value input via the input device 10, the user may select the image based on the sampling value displayed on the display device 60.

  The target tracking control unit 30 described above may have a computer system inside. In that case, the processing steps performed by the search range setting unit 31, the target image extraction unit 32, the target image distance calculation unit 33, and the search range calculation unit 34 described above are stored in a computer-readable recording medium in the form of a program. When the computer reads out and executes this program, the above processing is performed. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

It is a block diagram which shows the structure of the scanning sonar apparatus by this embodiment. It is a flowchart which shows operation | movement of the scanning sonar apparatus 1 in this embodiment. When the target image in this embodiment exceeds a reference range, it is an example of the image which the display apparatus before and behind the search range R displays. It is a figure which shows the concept of receiving of the reflected wave in a scanning sonar apparatus. When a target image exceeds a reference range, it is an example of an image displayed on a display device before and after the search range R is changed. When a target image exceeds a reference range, it is an example of an image displayed on a display device before and after the search range R is changed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Scanning sonar apparatus 10 ... Input device, 20 ... Operation control part 30 ... Target tracking control part, 31 ... Search range setting part, 32 ... Target image extraction part 33 ... Target image distance calculation part, 34 ... Search range calculation part 40 DESCRIPTION OF SYMBOLS ... Transmitter / receiver, 41 ... Transmitter, 42 ... Receiver 50 ... Display information converter, 60 ... Display device A ... Far end distance, B ... Near end distance, F ... Far threshold, N ... Near threshold, R ... Exploration range

Claims (3)

A target image extraction unit that extracts a target image representing the target from a plurality of sampling values according to the intensity of the reflected wave obtained by transmitting a sound wave from the transducer to the target and receiving the reflected wave;
A target image distance calculation unit that calculates a far-end distance that is a distance from the transceiver to the farthest part of the target from the target image extracted by the target image extraction unit;
A search range calculation unit that changes a search range by the sound wave according to the far end distance calculated by the target image distance calculation unit , and
The exploration range calculation unit
A remote threshold indicating whether to expand the search range;
A neighborhood threshold indicating whether or not to reduce the search range;
Remember
A scanning sonar device characterized by that . The exploration range calculation unit
When changing the search range, the far-end distance, according to claim 1, characterized in that to set the search range as the intermediate value between the distant threshold and the near threshold value as a new said search range Scanning sonar device. The exploration range calculation unit
When the search range is changed, the search range in which the estimated far end distance estimated from the history of the far end distance is an intermediate value between the far threshold and the neighborhood threshold is set as the new search range. The scanning sonar device according to claim 1 .

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