JP7419086B2 - Underwater detection device and how to display underwater detection images - Google Patents

Description

The present invention relates to an underwater detection device that transmits sound waves underwater and detects underwater conditions based on the reflected waves, and an underwater detection image display that displays an image on a display based on the signal strength of the reflected waves. Regarding the method.

2. Description of the Related Art Conventionally, underwater detection devices are known that transmit sound waves underwater and detect underwater conditions based on the reflected waves. In this type of device, for example, a transmitter and a receiver for transmitting and receiving ultrasonic waves are installed on the bottom of a ship, and the signal strength (volume data) of reflected waves is acquired in a three-dimensional detection range. Then, a surface image (three-dimensional image) of signal strength is generated based on the acquired volume data, and the generated surface image is displayed on a monitor or the like as a detection image of the detection range. By referring to the displayed detection images, the user can grasp the status of underwater targets such as schools of fish and shipwrecks.

Here, volume data can be obtained by various methods. For example, volume data is acquired by transmitting a flat, fan-shaped transmission beam directly below the bottom of the ship, acquiring intensity data of reflected waves, and accumulating the acquired intensity data in time series. With this configuration, underwater conditions can be displayed three-dimensionally using volume data accumulated over a predetermined period of time.

Patent Document 1 below describes this type of underwater detection device.

US Patent Application Publication No. 2016/0018515

Although underwater detection devices such as those described above can display the signal strength of the target object surface existing in the detection range in three dimensions from a predetermined viewpoint, the density inside the target object (signal strength distribution) and the distance It is not easy to understand the intensity distribution of other targets hidden in the displayed image.

In view of such problems, the present invention provides an underwater detection device and an underwater detection image that can easily grasp the intensity distribution inside the target object and the intensity distribution of other targets hidden in the back from images generated by volume data. The purpose is to provide a display method for

A first aspect of the present invention relates to an underwater detection device. The underwater detection device according to this aspect slices volume data indicating the distribution of signal strength of reflected waves in a three-dimensional detection range on a slice plane according to an operation on the operation unit, and slices volume data indicating the distribution of signal intensity of reflected waves in a three-dimensional detection range, and based on the volume data on the slice plane. , a signal processing section that causes a display section to display a cross-sectional image showing a distribution of signal intensity.

According to the underwater detection device according to this aspect, the user can grasp the signal strength at the slice position (on the slice plane) by referring to the cross-sectional image. Further, the user can move the slice position of the cross-sectional image according to the operation on the operation unit. By moving the slice position of the cross-sectional image in this way, the user can easily grasp the intensity distribution inside the target object and the intensity distribution inside other targets hidden behind the target object.

In the underwater detection device according to this aspect, the signal processing unit generates a detection image indicating the distribution of signal strength when viewed from a predetermined viewpoint based on the volume data, and causes the display unit to display the generated detection image. It can be configured as follows.

According to this configuration, the user can understand the distribution of signal intensity at a predetermined slice position using the cross-sectional image, and can also understand the distribution of signal intensity over the entire detection range using the detection image.

In this case, the signal processing unit may be configured to display the cross-sectional image superimposed on the detection image.

According to this configuration, the user can grasp the signal strength at the cross-sectional position using the cross-sectional image, and at the same time grasp the signal strength at positions other than the cross-sectional position using the detection image. Therefore, the user can also grasp whether there are other targets such as a school of fish at a location other than the cross-sectional image, and can smoothly find the school of fish to be confirmed.

In this case, the signal processing unit may be configured to set the detected image closer to the viewpoint than the slice plane of the cross-sectional image to non-display.

According to this configuration, it is possible to prevent the cross-sectional image from becoming difficult to see due to the detected image on the viewpoint side of the cross-sectional image. Therefore, the user can confirm the cross-sectional image more clearly.

Alternatively, the signal processing unit may be configured to set the detected image closer to the viewpoint than the slice plane of the cross-sectional image to transparent display.

According to this configuration, the user can check the signal strength in the cross-sectional image and also check the signal strength in the detection image on the viewpoint side than the cross-sectional image.

In the underwater detection device according to this aspect, the signal processing section may display the cross-sectional image on the display section separately from the detection image.

According to this configuration, the user can satisfactorily understand the entire detected image as well as the cross-sectional image.

In the underwater detection device according to this aspect, the signal processing section may be configured to accept selection of the moving direction of the slice plane via the operation section.

According to this configuration, the moving direction of the cross-sectional image can be changed in a direction desired by the user. Therefore, the user can proceed with the signal strength confirmation work more efficiently.

Here, it is preferable that the moving direction of the slice plane includes a vertical direction.

In this case, the user can move the cross-sectional image in the direction of water depth, thereby smoothly confirming schools of fish etc. that gather at a predetermined water depth.

Alternatively, the moving direction of the slice plane may include the viewing direction.

In this case, the direction in which the user refers to the detected image can be matched with the direction in which the cross-sectional image moves in response to the operation. As a result, the user can intuitively visualize the movement of the cross-sectional image, and can smoothly move the cross-sectional image and confirm the school of fish.

In addition, the moving direction of the slice plane may include other directions such as a horizontal direction.

In the underwater detection device according to this aspect, the signal processing section may be configured to set a signal intensity measurement position on the cross-sectional image in response to an operation on the operation section.

According to this configuration, the user can easily specify, for example, a position where the signal intensity is high on the cross-sectional image as the measurement position.

In this case, the signal processing unit may be configured to set a predetermined three-dimensional range including the measurement position as the signal strength measurement range.

According to this configuration, the signal strength of a target object such as a school of fish included in the measurement range can be smoothly extracted and measured.

In this case, the signal processing section may be configured to display the measurement range on the detection image and change the size of the measurement range in accordance with an operation on the operation section.

According to this configuration, the user can smoothly adjust the measurement range to the range of the school of fish, etc., while referring to the detection image and the display of the measurement range, for example. Thereby, the user can appropriately measure the signal strength of the measurement target.

In the above configuration, the signal processing section may be configured to display a histogram of signal intensities included in the measurement range on the display section.

Alternatively, the signal processing unit may be configured to display information regarding the amount of fish included in the measurement range on the display unit based on the signal strength included in the measurement range.

According to these configurations, the user can easily grasp the density of the fish school and the total amount of fish in the fish school.

A second aspect of the present invention relates to a method for displaying underwater detection images. The method for displaying an underwater detection image according to this aspect is to slice volume data indicating the distribution of signal strength of reflected waves in a three-dimensional detection range on a slice plane according to an operation on the operation unit, and display the volume data on the slice plane. A cross-sectional image showing the distribution of signal intensity is displayed on the display unit based on the cross-sectional image.

According to the underwater detection image display method according to this aspect, the same effects as in the first aspect can be achieved.

As described above, according to the present invention, an underwater detection device and an underwater detection device are capable of easily grasping the intensity distribution inside a target object and the intensity distribution of other targets hidden in the background from an image generated by volume data. A method for displaying images can be provided.

The effects and significance of the present invention will become clearer from the following description of the embodiments. However, the embodiment shown below is merely one example of implementing the present invention, and the present invention is not limited to what is described in the embodiment below.

FIG. 1 is a block diagram showing the configuration of an underwater detection device according to an embodiment. FIG. 2 is a diagram schematically showing a voxel setting method according to the embodiment. FIG. 3 is a diagram schematically showing the relationship between volume data and slice planes according to the embodiment. FIG. 4 is a flowchart illustrating processing for measuring the amount of fish and the like using detected images and cross-sectional images, according to the embodiment. FIG. 5 is a flowchart illustrating processing for measuring the amount of fish and the like using detected images and cross-sectional images, according to the embodiment. FIG. 6 is a diagram showing a screen displayed on the display unit during measurement processing according to the embodiment. FIG. 7 is a diagram showing a screen displayed on the display unit during measurement processing according to the embodiment. FIG. 8 is a diagram showing a screen displayed on the display unit during measurement processing according to the embodiment. FIG. 9 is a diagram showing a screen displayed on the display unit during measurement processing according to the embodiment. FIG. 10 is a diagram showing a screen displayed on the display unit during measurement processing according to the embodiment. FIG. 11A is a diagram showing a subroutine executed in cross-sectional image display processing according to the embodiment. FIG. 11(b) is a diagram illustrating a subroutine executed in a cross-sectional image display process according to modification example 1. FIGS. 12(a) and 12(b) are diagrams each schematically showing the relationship between the volume data and the slice plane when the slice plane is moved in the horizontal direction according to Modification Example 2. FIG. 13 is a diagram schematically showing the relationship between the volume data and the slice plane when the slice plane is moved in the viewing direction according to Modification Example 2. FIG. 14 is a diagram showing a screen displayed on the display unit in measurement processing according to modification example 2. FIG. 15 is a diagram showing the configuration of a screen displayed on the display unit in measurement processing according to modification example 3.

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

FIG. 1 is a block diagram showing the configuration of an underwater detection device 10. As shown in FIG.

The underwater detection device 10 includes a wave transmitter 11 and a wave receiver 12. The wave transmitter 11 and the wave receiver 12 may be installed on the bottom of the ship so as to face underwater, or the wave transmitter 11 and the wave receiver 12 may be installed as a unit on the bottom of the ship.

The transmitter 11 and the receiver 12 are, for example, ultrasonic transducers. For example, the transmitter 11 has a configuration in which a plurality of ultrasonic transducers are lined up in a row. A sinusoidal transmission signal is applied to each ultrasonic transducer. As a result, ultrasonic waves are transmitted from each ultrasonic transducer. By controlling the phase of the transmission signal applied to each ultrasonic transducer, a transmission beam with a predetermined thickness is formed. The transmitted beam spreads out in a fan shape with a predetermined apex angle (eg, 120°) when viewed in the thickness direction. In this embodiment, the transmission beam is transmitted vertically downward. That is, the transmission beam is transmitted into the water so that the straight line that bisects the apex angle of the fan shape of the transmission beam is parallel to the vertical direction.

The receiver 12 has, for example, a configuration in which a plurality of ultrasonic transducers are arranged in a row. For example, the direction in which the ultrasonic transducers of the receiver 12 are arranged is perpendicular to the direction in which the ultrasonic transducers of the transmitter 11 are arranged. That is, the ultrasonic transducers of the receiver 12 are aligned in the direction in which the transmission beam spreads (in the direction in which the fan shape spreads). The directions in which the ultrasonic transducers of the transmitter 11 and the receiver 12 are arranged do not necessarily have to be perpendicular, but may be directions that intersect with each other.

The reflected waves of the ultrasonic waves transmitted from the wave transmitter 11 are received by each ultrasonic transducer of the wave receiver 12 . Each ultrasonic transducer of the wave receiver 12 outputs a received signal of a magnitude corresponding to the intensity of the reflected wave. By performing phase control (beamforming) on the received signal, a plurality of receiving beams are formed that are aligned in the direction of the spread angle (the apex angle of the sector) of the transmitted beam. Thereby, a received signal of a reflected wave is generated for each receiving beam, that is, for each predetermined angle in the direction of the spread angle (vertical angle of the sector) of the transmitting beam. As the pitch of the receive beams is reduced and the number of receive beams is increased, the resolution of underwater detection in the direction of the spread angle (vertical fan angle) of the transmit beams increases.

The rotation drive unit 13 rotates the wave transmitter 11 and the wave receiver 12 integrally about an axis parallel to the vertical direction. Thereby, the above-mentioned transmitting beam and receiving beam rotate integrally about the above-mentioned axis. In this way, by rotating each beam, it is possible to obtain received signals all around the ship in the horizontal direction, and to detect underwater conditions all around the ship. The rotation drive unit 13 includes a motor as a drive source and a rotary encoder for detecting a rotational position. The detection signal of the rotary encoder is optionally input to the signal processing section 17.

Further, the underwater detection device 10 includes a transmission control section 14 , a reception beam forming section 15 , a drive control section 16 , a signal processing section 17 , an operation section 18 , and a display section 19 . The transmission control section 14, reception beam forming section 15, drive control section 16, signal processing section 17, operation section 18, and display section 19 are installed in a ship's wheelhouse or the like. These components may be unitized into one housing, or some components such as the display section 19 may be separated. The transmission control section 14, reception beam forming section 15, and drive control section 16 are communicably connected to the wave transmitter 11, the wave receiver 12, and the drive control section 16, respectively, by signal cables.

The transmission control section 14 outputs a transmission signal to the transmitter 11 under control from the signal processing section 17 . As described above, the transmission control unit 14 supplies a transmission signal to the ultrasonic transducer of the wave transmitter 11 so that a flat transmission beam that spreads in a fan shape is formed.

As described above, the reception beam forming unit 15 applies beamforming processing to the reception signals inputted from each ultrasonic transducer of the wave receiver 12, and converts the transmission beam in the angular direction of the fan-shaped apex angle. Forms multiple receive beams lined up. Then, the reception beam forming section 15 outputs the reception signal to the signal processing section 17 for each reception beam.

The drive control section 16 controls the rotation drive section 13 under control from the signal processing section 17 . As a result, as described above, the transmitter 11 and the receiver 12 rotate integrally, and accordingly, the transmitting beam and the receiving beam rotate integrally.

The signal processing section 17 controls each section according to a pre-held program. Further, the signal processing unit 17 processes the reception signal input from the reception beam forming unit 15 to generate an image of the detection range (the range in which the transmission beam rotates once), and causes the display unit 19 to display the image. The signal processing unit 17 includes an arithmetic processing circuit such as a CPU (Central Processing Unit), and a storage medium such as a ROM (Read Only Memory), a RAM (Random Access Memory), and a hard disk. The above program is held in a storage medium. The signal processing unit 17 may be configured with an integrated circuit such as an FPGA (Field-Programmable Gate Array).

Note that the signal processing section 17 does not necessarily have to be composed of one integrated circuit, and may be composed of a combination of a plurality of integrated circuits or arithmetic processing circuits. For example, the signal processing unit 17 includes an arithmetic processing circuit for controlling the transmitter 11 and the rotation drive unit 13, and an arithmetic processing circuit for processing the received signal input from the receiving beam forming unit 15 to generate a detection image. A processing circuit may be provided separately.

The operation unit 18 is a user interface that accepts input from the user. The operation unit 18 includes input means such as a mouse and a keyboard. The operation unit 18 may include a touch panel integrated into the display unit 19. In this embodiment, the operation unit 18 includes a mouse 100, and as described later, the mouse 100 is used to input operations on the detected image and the cross-sectional image. A wheel 101, a left-click operator 102, and a right-click operator 103 are arranged on the top surface of the mouse 100. In addition, a sensor for detecting movement of the mouse 100 is arranged on the bottom surface of the mouse 100.

The display unit 19 displays the image generated by the signal processing unit 17. The display unit 19 includes a display such as a monitor or a liquid crystal panel. As described later, a detected image and a cross-sectional image are displayed on the display unit 19. In addition, the underwater detection device 10 includes a configuration for detecting direction and position, such as GPS (Global Positioning System).

The signal processing unit 17 acquires the signal strength (volume data) of the reflected waves for the three-dimensional detection range in which the transmission beam rotates. Specifically, the signal processing unit 17 divides the fan-shaped transmission beam into each angular range (angular range of each receiving beam formed by the receiving beam forming unit 15) with a predetermined resolution in the angular direction of the apex angle. , refer to the received signal. Here, half of the time difference between the timing of transmitting the transmission beam and the timing of receiving the reflected wave corresponds to the distance to the target object that reflected the reflected wave. The signal processing unit 17 associates the elapsed time from the timing of transmitting the transmission beam with the strength of the reception signal for each reception beam. That is, the signal processing unit 17 acquires the strength of the received signal at regular time intervals from the timing at which the transmission beam is transmitted.

In this way, a data group is obtained that associates the elapsed time (distance) with the strength of the received signal for each angular range of each received beam. The signal processing unit 17 repeatedly performs the above processing at every predetermined rotation angle while the transmission beam makes one rotation in the horizontal direction. As a result, a data group is acquired that associates elapsed time (distance) with received signal strength for the entire detection range surrounding the entire circumference of the ship. The signal processing unit 17 maps the data group obtained through this processing to predefined voxels by linear interpolation processing.

FIG. 2 is a diagram schematically showing a method of setting voxel B1. For convenience, XYZ axes that are orthogonal to each other are shown in FIG. The XY plane is parallel to the horizontal plane. The Y-axis positive direction is the traveling direction of the ship 20, and the Z-axis positive direction is the water depth direction.

As shown in FIG. 2, a rectangular parallelepiped area (the entire area from which volume data VD is acquired) is set directly below the ship 20 (directly below the transmitter 11 and receiver 12), and this area is One voxel B1 is set evenly divided into the following. Voxel B1 has a cubic shape. For convenience of explanation, the rectangular parallelepiped area and the fineness of the voxels that define the range of the volume data VD are set as shown in FIG. 2, but the setting method is not limited to this. The size of the rectangular parallelepiped area in the XYZ axis directions may be larger than the size shown in FIG. 2 . The rectangular parallelepiped region may extend to near the sea surface where the ship 20 floats. Furthermore, the size of the voxel B1 in the XYZ axis directions is actually smaller than the size shown in FIG.

The signal processing unit 17 maps the signal strength data around the entire circumference of the ship 20 obtained through the above processing to each voxel B1 by linear interpolation processing. As a result, data indicating the strength of the received signal is mapped to all voxels B1 set in the rectangular parallelepiped area, and volume data VD of the entire area is acquired. The volume data VD is updated as needed as the transmission beam rotates. In this way, the latest volume data VD is acquired as the ship 20 advances.

Returning to FIG. 1, the signal processing unit 17 generates a detection image based on the volume data VD acquired through the above processing, and causes the display unit 19 to display the detected image. For example, the signal processing unit 17 performs processing such as volume rendering on the volume data VD to generate a three-dimensional image (detection image) showing the distribution of signal strength when the detection range is referred to from a predetermined viewpoint. The detection image is colored according to the signal strength of the reflected waves. The bottom of the water may be given a color different from the color corresponding to the signal strength. The viewpoint of the detected image may be changeable by operating the operating unit 18.

Furthermore, in this embodiment, a cross-sectional image obtained by slicing the detected image along a slice plane parallel to the horizontal plane is displayed. The slice plane can be moved in the vertical direction by operating the operating unit 18 (mouse 100). The cross-sectional image displays the distribution of signal intensity of reflected waves in the cross-section.

FIG. 3 is a diagram schematically showing the relationship between the volume data VD and the slice plane S1.

As described above, the slice plane S1 is parallel to the horizontal plane (XY plane). The cross-sectional image reflects the signal intensity of the voxel B1 (see FIG. 2) that intersects the slice plane S1. The slice plane S1 can be moved in the vertical direction D1 by operating the operating unit 18 (mouse 100). Therefore, the user can refer to a cross-sectional image of a cross-section that changes in the vertical direction D1 by operating the operation unit 18 (mouse 100).

In addition, in this embodiment, a measurement range can be set within the detection range, and the amount of fish included in the measurement range can be measured. The user can set the measurement range at a desired position while referring to the cross-sectional image. Furthermore, the user can arbitrarily adjust the size of the measurement range. In this embodiment, the measurement range has a cubic shape. However, the shape of the measurement range is not limited to a cube, and may be other shapes such as a sphere or a rectangular parallelepiped.

FIGS. 4 and 5 are flowcharts showing processing for measuring the amount of fish and the like using a detection image and a cross-sectional image, respectively. Further, FIGS. 6 to 10 are diagrams showing screens displayed on the display unit 19 during the measurement process.

First, referring to FIG. 6, the signal processing unit 17 displays a screen 30 including a detection image 31 generated based on the volume data VD. As described above, the detection image 31 is a three-dimensional image that shows the distribution of signal strength when the detection range is referred to from a predetermined viewpoint. In addition to the detection image 31 , the screen 30 includes a ship image 32 , a ship's bow and stern object 33 , and an operation area 34 . The operation area 34 includes an item 34a for measuring the amount of fish. When the user operates the item 34a via the mouse 100, the measurement process shown in FIG. 4 is started.

Referring to FIG. 4, the signal processing unit 17 changes the viewing direction of the detected image to the moving direction of the slice plane S1 and displays the detected image (S101). Further, the signal processing unit 17 sets the slice plane S1 to an initial position (eg, water surface position) (S102). As a result, the screen 40 in FIG. 7 is displayed instead of the screen 30 in FIG. 6. Here, as a result of the process in step S101 in FIG. 4, the screen 40 includes a detected image 41 when the viewing direction is vertically downward.

The screen 40 also includes a ship image 42 and an area 43 indicating the position of the slice plane. In area 43, an image of the slice plane viewed in the horizontal direction is shown. The area 43 includes a bar 43a indicating the position of the slice plane, a ship image 43b, water depth information 43c of the slice plane, and a measurement frame 43d. Here, since the slice surface is set to the water surface position by the process of step S102 in FIG. 4, the bar 43a and the water depth information 43c are set to positions and information corresponding to the water surface position, respectively. In addition, the screen 40 includes an operation area 44 and an item 44a, similar to the screen 30 of FIG.

Returning to FIG. 4, when the wheel 101 of the mouse 100 is operated, the signal processing unit 17 moves the slice plane S1 in the vertical direction D1 according to the rotation direction and rotation amount of the wheel 101, and converts the cross-sectional image into a cross-sectional image. It is displayed on the screen 40 (S103). Further, when the cursor overlaps the detection range due to movement of the mouse 100 with respect to the mounting surface, the signal processing unit 17 displays a measurement frame indicating the measurement range at the cursor position (S104).

In this way, by executing steps S103 and S104 in FIG. 4, the screen 40 in FIG. 7 changes as shown in FIG. 8, for example. That is, as the slice plane S1 moves by operating the wheel 101, the bar 43a of the region 43 and the water depth information 43c change. Here, it is shown that the slice plane S1 has moved to a position at a depth of 78 m. Furthermore, the measurement frame 43d in the area 43 is positioned at a position on the slice plane S1 according to the movement of the mouse 100. In addition, the area 43 includes an image 43e showing the bottom of the water.

Further, the signal processing unit 17 causes the cross-sectional image 45 of the volume data VD sliced at the slice plane S1 to be displayed superimposed on the detection image 41 through the process of step S103 in FIG.

In this embodiment, the detected image 41 on the viewpoint side (vertically above) the slice plane S1 is set to be hidden. Furthermore, in the volume data VD on the slice plane S1, the detection image 41 is displayed with a mesh that reduces the clarity attached to the position of the voxel B1 whose signal strength is lower than the level at which the display color is applied. be done. That is, in the volume data VD on the slice plane S1, a display color corresponding to the signal strength is assigned to the position of the voxel B1 whose signal strength is equal to or higher than the lower limit level to which the display color is assigned, thereby forming the cross-sectional image 45. The detection image 41 is displayed in a range other than the cross-sectional image 45 with a mesh that reduces the clarity attached. As a result, the cross-sectional image 45 is displayed more clearly than the detected image 41. The user can easily distinguish between the cross-sectional image 45 and the detected image 41 due to the difference in sharpness.

Furthermore, the signal processing unit 17 displays the measurement frame 46 superimposed on the detection image 41 and the cross-sectional image 45, as shown in FIG. 8, through the process of step S104 in FIG. The measurement frame 46 moves on the slice plane S1 as the mouse 100 moves.

Returning to FIG. 4, the signal processing unit 17 repeats the processing of steps S103 and S104 until the user performs a decision operation (S105) or an end operation (S106) via the mouse 100. Here, the decision operation (S105) is an operation of left-clicking the mouse 100 (an operation of pressing the operator 102 in FIG. 1). Further, the termination operation (S106) is an operation in which the user operates item 44a in FIG. 8 to switch item 44a to measurement OFF. When the termination operation is performed (S106: YES), the signal processing unit 17 terminates the process of FIG. 4 and returns the screen to the screen 30 of FIG. 6.

The user operates the wheel 101 of the mouse 100 to refer to the cross-sectional images 45 at each water depth and confirm the presence of schools of fish and the like. Then, the user moves the mouse 100 while displaying a desired cross-sectional image 45 including a school of fish, and positions the measurement frame 46 at the position of the school of fish on the cross-sectional image 45. Thereafter, the user operates the operator 102 of the mouse 100 (left click) to determine the position of the measurement frame 46.

When the user performs the determination operation (S105: YES), the signal processing unit 17 advances the process to step S107 in FIG. 5. The signal processing unit 17 ends the display processing of the cross-sectional image 45 (S107), and displays the detected image on the display unit 19 from the normal display viewpoint (S108). Then, the signal processing unit 17 displays a three-dimensional measurement frame at the water depth position and horizontal position of the measurement frame 46 determined in step S105 of FIG. 4 (S109). Further, the signal processing unit 17 measures the total amount of fish in the school of fish included in the measurement frame based on the signal strength of voxel B1 included in the three-dimensional measurement frame, and displays the measurement result on the display unit 19. (S110).

Through steps S107 to S110 in FIG. 5, for example, the screen 50 in FIG. 9 is displayed.

The screen 50, like the screen 30 in FIG. 6, includes a detection image 51, a ship image 52, a bow and stern object 53, an operation area 54, and an item 54a. The line of sight direction of the detection image 51 is the same as in the case of FIG. Furthermore, the screen 50 includes a three-dimensional measurement frame 55 and an area 56 showing measurement results. As described above, the measurement frame 55 is displayed at the water depth position and horizontal position of the measurement frame 46 determined in step S105 of FIG. 4. The measurement frame 55 is displayed in a size set by default.

In the area 56, the fish amount 56a of the school of fish included in the measurement frame 55 is displayed in tons. The signal processing unit 17 calculates the fish amount 56a by multiplying the total volume of each signal strength of voxel B1 included in the measurement frame 55 by a predetermined coefficient for each signal strength. This coefficient can be selected depending on the type of fish, etc. Further, in the area 56, frame information 56b including the length, width, and height dimensions of the measurement frame 55 and the water depth position of the measurement frame 55 is displayed. Further, in the area 56, a histogram 56c indicating the frequency distribution of the signal intensity of the voxel B1 included in the measurement frame 55 is displayed. The user can roughly grasp the density of the fish school included in the measurement frame 55 by referring to the histogram 56c. The user can change the size of the measurement frame 55 by operating the wheel 101 of the mouse 100.

Returning to FIG. 5, when the user operates the wheel 101 of the mouse 100, the signal processing unit 17 similarly increases or decreases the measurement frame 55 according to the rotation direction and rotation amount of the wheel 101 (S111). That is, when the wheel 101 rotates in one direction, the measurement frame 55 becomes larger according to the amount of rotation, and when the wheel 101 rotates in the other direction, the measurement frame 55 becomes smaller depending on the amount of rotation. The measurement frame 55 can be changed between a preset maximum size and a preset minimum size.

FIG. 10 shows the screen 50 when the measurement frame 55 becomes larger from the state shown in FIG. 9 due to the operation on the wheel 101. As the size of the measurement frame 55 changes, the amount of fish 56a in the area 56, the frame information 56b, and the histogram 56c change. The user can adjust the measurement frame 55 to a desired size and check the amount of fish included in the measurement frame 55.

Returning to FIG. 5, the signal processing unit 17 repeats the processing of steps S110 and S111 until the user performs a cancel operation (S112) or an end operation (S113) via the mouse 100. Here, the cancellation operation (S112) is an operation of right-clicking the mouse 100 (an operation of pressing the operator 103 in FIG. 1). Further, the end operation (S113) is an operation in which the user operates the item 54a in FIGS. 9 and 10 to switch the item 54a to measurement OFF. When the end operation is performed (S113: YES), the signal processing unit 17 ends the process of FIG. 5 and returns the screen to the screen 30 of FIG. 6.

After referring to the measurement results in FIGS. 9 and 10, the user performs a cancellation operation (right-click) using the mouse 100 when measuring schools of fish at other water depths. Thereby, the signal processing unit 17 makes the determination in step S112 of FIG. 5 YES, and returns the process to step S103 of FIG. 4. This returns the screen to the screen shown in FIG. Thereafter, the user operates the wheel 101 in the same manner as described above to display the cross-sectional image 45 at the desired water depth. Then, the user moves the mouse 100, positions the measurement frame 46 at the position of the school of fish on the cross-sectional image 45, and performs a left-click operation (decision operation) on the mouse 100. As a result, a measurement frame 55 similar to that shown in FIG. 9 is set at the position of the school of fish, and the school of fish is measured. As a result, information regarding the school of fish is displayed in the area 56. In this way, the user can smoothly obtain information regarding other fish schools.

<Effects of embodiment>
According to the above embodiment, the following effects can be achieved.

The user can understand the signal intensity at the cross-sectional position by referring to the cross-sectional image 45 shown in FIG. Further, the user can move the slice position of the cross-sectional image 45 in the vertical direction D1 according to an operation on the operation unit 18 (mouse 100). By moving the cross-sectional image 45 in this manner, the user can easily grasp the intensity distribution inside the target object and the intensity distribution inside other targets hidden behind the target object.

Further, the signal processing unit 17 further displays the detected image 41 on the display unit 19. Thereby, the user can understand the distribution of signal intensity at a predetermined slice position using the cross-sectional image 45, and can also understand the distribution of signal intensity in the entire detection range using the detection image 41.

As shown in FIG. 8, the signal processing unit 17 displays the cross-sectional image 45 superimposed on the detection image 41. As a result, the user can grasp the signal strength at the cross-sectional position using the cross-sectional image 45 and the signal strength farther from the cross-sectional position using the detection image 41. Therefore, the user can also know whether there are further targets such as a school of fish behind the cross-sectional position, and can smoothly find the school of fish to be measured.

Furthermore, in this embodiment, as shown in FIG. 8, the detection image 41 on the viewpoint side of the slice plane of the cross-sectional image 45 is set to be hidden. This can prevent the cross-sectional image 45 from becoming difficult to see due to the detection image 41 located closer to the viewpoint than the cross-sectional image 45. Therefore, the user can see the cross-sectional image 45 more clearly.

Further, as shown in FIG. 3, in this embodiment, the slice plane S1 is moved in the vertical direction D1 in response to the operation of the operation unit 18 (mouse 100), and the cross-sectional image 45 is generated. Thereby, the user can move the cross-sectional image 45 in the water depth direction, and can smoothly confirm schools of fish etc. that gather at a predetermined water depth.

Further, as shown in FIG. 8, the signal processing unit 17 sets a signal intensity measurement position (measurement frame 46) on the cross-sectional image 45 in response to an operation on the operation unit 18 (mouse 100). Thereby, the user can easily specify, for example, a position with high signal strength (position of a school of fish) on the cross-sectional image 45 as a measurement position.

Further, as shown in FIG. 9, the signal processing unit 17 sets a predetermined three-dimensional range (measurement frame 55) including the measurement position (measurement frame 46) set on the screen 40 of FIG. Set. Thereby, the signal strength of a target object such as a school of fish included in the measurement range (measurement frame 55) can be smoothly extracted and measured.

Further, as shown in FIGS. 9 and 10, the signal processing unit 17 displays the measurement range (measurement frame 55) on the detection image 51, and displays the measurement range in accordance with the operation on the operation unit 18 (mouse 100). Change the size of (measurement frame 55). Thereby, the user can smoothly adjust the measurement range (measurement frame 55) to a range such as a school of fish while referring to the display of the detection image 51 and the measurement range (measurement frame 55). Thereby, the user can appropriately measure the signal strength of the measurement target.

Further, as shown in FIGS. 9 and 10, the signal processing unit 17 causes the display unit 19 to display a histogram 56c of the signal strength included in the measurement range (measurement frame 55), and further displays the histogram 56c of the signal strength included in the measurement range (measurement frame 55). ), information regarding the amount of fish (amount of fish 56a) included in the measurement range (measurement frame 55) is displayed on the display unit 19. These displays allow the user to easily grasp the density of the fish school and the total amount of fish in the fish school.

<Change example 1>
The present invention is not limited to the above embodiments. Furthermore, the embodiments of the present invention can be modified in various ways in addition to the above configuration.

For example, in the above embodiment, in step S103 in FIG. 4, the detected image 41 on the viewpoint side of the slice plane S1 is set to be hidden, but the detected image 41 on the viewpoint side of the slice plane S1 is set to be transparently displayed. may be done.

11(a) is a subroutine showing the process in step S103 of FIG. 4 according to the above embodiment, and FIG. 11(b) is a subroutine showing the process in step S103 of FIG. 4 according to modification example 1. be.

First, the processing in the above embodiment will be described with reference to FIG. 11(a). In step S103 of FIG. 4, the signal processing unit 17 assigns a display color corresponding to the signal strength to the position of the voxel B1 whose signal strength is equal to or higher than the lower limit level for assigning a display color, among the voxels B1 included in the slice plane S1. Then, the cross-sectional image 45 is displayed (S201). Here, the signal processing unit 17 excludes other voxels B1 included in the slice plane S1 from the display target. In addition, the signal processing unit 17 sets the detection image 41 on the viewpoint side of the slice plane S1 to be hidden (S202), and displays the area other than the cross-sectional image 45 in the area of the detection image 41 on the back side of the slice plane. The detected image 41 of this area is displayed by applying mesh processing to reduce the clarity (S203). Here, the signal processing unit 17 sets the detected image 41 to be hidden in the area that overlaps the cross-sectional image 45 among the areas of the detected image 41 on the back side of the slice plane.

Next, processing in modification example 1 will be described with reference to FIG. 11(b). In step S103 of FIG. 4, the signal processing unit 17 displays a cross-sectional image through the process of step 201, as in FIG. 11(a). Then, the signal processing unit 17 sets the detection image 41 on the viewpoint side of the slice plane S1 to transparent display (S211), and displays the area other than the cross-sectional image 45 in the area of the detection image 41 on the back side of the slice plane. The detected image 41 of this area is displayed by applying mesh processing to reduce the clarity (S203). In step S211, the signal processing unit 17 sets the detected image 41 to be transparently displayed by setting the parameter α that defines the degree of transparency in the video signal to a predetermined value. Thereby, the cross-sectional image 45 can be displayed while the detection image 41 on the viewpoint side is displayed faintly.

According to the process of modification example 1, since the detected image 41 on the viewpoint side of the slice plane S1 of the cross-sectional image 45 is set to transparent display, the cross-sectional image 45 becomes somewhat difficult to see, the user can check the signal strength in the cross-sectional image 45 and also check the signal strength in the detection image 41 on the viewpoint side of the cross-sectional image 45. Therefore, the user can also grasp whether there are any other targets such as a school of fish in front of the cross-sectional image 45, and can smoothly confirm the school of fish to be confirmed.

<Change example 2>
In the embodiment described above, the moving direction of the slice surface S1 was only the vertical direction D1. In contrast, in Modification Example 2, a plurality of directions of movement of the slice plane are prepared, and the user can select a desired direction of movement.

12(a) and 12(b) schematically show the relationship between the volume data VD and the slice planes S2 and S3 when the slice planes S2 and S3 are moved in the horizontal direction, respectively, according to modification example 2. FIG.

In the case of FIG. 12(a), the slice plane S2 is parallel to the vertical plane (YZ plane). The cross-sectional image reflects the signal intensity of the voxel B1 (see FIG. 2) that intersects the slice plane S2. The slice plane S2 is moved in a horizontal direction D2 parallel to the X-axis by an operation on the operation unit 18 (mouse 100). Therefore, the user can refer to a cross-sectional image of a cross-section that changes in the horizontal direction D2 by operating the operation unit 18 (mouse 100).

In the case of FIG. 12(b), the slice plane S3 is parallel to the vertical plane (XZ plane). The cross-sectional image reflects the signal intensity of the voxel B1 (see FIG. 2) that intersects the slice plane S3. The slice plane S3 is moved in the horizontal direction D3 parallel to the Y axis by operation on the operation unit 18 (mouse 100). Therefore, the user can refer to a cross-sectional image of a cross-section that changes in the horizontal direction D3 by operating the operation unit 18 (mouse 100).

FIG. 13 is a diagram schematically showing the relationship between the volume data VD and the slice plane S4 when the slice plane S4 is moved in the viewing direction according to modification example 2.

In FIG. 13, the viewing direction is indicated by a dashed arrow. P1 is a virtually set viewpoint position. The viewing direction is, for example, the same as the viewing direction for the detected image 31 shown in FIG.

In the case of FIG. 13, the slice plane S4 is perpendicular to the viewing direction. The cross-sectional image reflects the signal intensity of the voxel B1 (see FIG. 2) that intersects the slice plane S4. The slice plane S4 is moved in the line-of-sight direction D4 by operating the operation unit 18 (mouse 100). Therefore, the user can refer to a cross-sectional image of a cross-section that changes in the line-of-sight direction D4 by operating the operation unit 18 (mouse 100).

FIG. 14 is a diagram showing a screen 40 according to modification example 2.

Screen 40 in FIG. 14 is a screen that is displayed immediately after the user operates item 34a on screen 30 in FIG. 6 and measurement processing is started. Here, the screen 40 for moving the slice plane S1 in the vertical direction is displayed as the default screen, similar to FIG. 7. The operation area 44 of the screen 40 includes an item 44b for changing the moving direction of the cross section (slice plane). By operating item 44b, the user can arbitrarily change the moving direction of the cross section from the vertical direction shown in FIG. 14 to the horizontal direction shown in FIGS. Can be switched.

When the moving direction of the cross section is changed, the detected image 41 is changed to the detected image when viewed in the changed moving direction. Along with this, the display form of the ship image 42 is also changed. Further, the orientation of the bar 43a and the orientation of the ship image 43b displayed in the area 43 are changed to correspond to the moving direction of the cross section. Furthermore, the position of the measurement frame 43d on the bar 43a moves as the mouse 100 moves.

The processing after the cross-section moving direction is changed differs from the above embodiment only in the moving direction of each slice plane and the screen display format, and the processing content itself is the same as the processing in FIGS. 4 and 5. be. After moving the measurement frame 43d, the direction of the cross-sectional image may be switched according to the operation of the item 44b.

According to the configuration of Modification Example 2, the moving direction of the cross-sectional image can be changed in a direction desired by the user. Therefore, the user can proceed with the signal strength confirmation work more efficiently.

Furthermore, as shown in FIG. 13, by including the line of sight direction in the moving direction of the cross-sectional image, the direction in which the detected image is referred to can be matched with the direction in which the cross-sectional image moves in accordance with the operation. As a result, the user can intuitively visualize the movement of the cross-sectional image, and can smoothly move the cross-sectional image and confirm the school of fish.

Note that the selectable movement direction of the cross-sectional image (the movement direction of the slice plane) is not limited to the movement directions of FIGS. 3, 12(a), 12(b), and 13. For example, the line-of-sight direction may be arbitrarily set, and the cross-sectional image (slice plane) may be moved in the set line-of-sight direction. Further, the direction of horizontal movement of the slice plane may also be a direction inclined from the X-axis direction and the Y-axis direction.

<Change example 3>
In the above embodiment, the cross-sectional image 45 is displayed superimposed on the detected image 41, but the cross-sectional image 45 may be displayed separately from the detected image 41.

FIG. 15 is a diagram showing the configuration of the screen 40 according to modification example 3.

In the display form of FIG. 15, a cross-sectional image display area 47 is set apart from the detected image 41. The display area 47 includes a cross-sectional image 47a, a ship image 47b, and water depth information 47c. Water depth information 47c indicates the water depth position of the slice surface. As in the above embodiment, the user can change the water depth position of the slice surface S1 by operating the wheel 101 of the mouse 100.

In this display form, a measurement frame is displayed in the display area 47. The detection image 41 does not necessarily have to be a detection image viewed vertically downward, but may be a detection image viewed in the normal line of sight direction as in FIG. 6.

According to modification example 3, since no hidden area or transparent area is set in the detected image 41, the user can clearly see the entire detected image 41 along with the cross-sectional image 47a.

<Other change examples>
In the embodiment described above, various operation inputs are performed using the mouse 100 during measurement processing, but the method of operation input is not limited to this. For example, in the case of a configuration in which inputs to the screen of the display unit 19 are accepted by a touch panel, operation inputs during measurement processing may be received by operations on the screen. For example, the measurement frame 46 shown in FIG. 8 may be moved by a drag operation on the screen, and the position of the measurement frame 46 may be determined by a tap operation on the measurement frame 46.

Further, the layout of each screen is not limited to the layout shown in the above embodiment, and other layouts may be used as long as the detected image and the cross-sectional image are appropriately displayed.

Further, the method of acquiring the volume data VD is not limited to the method of the above embodiment, and other methods may be used. For example, a method of acquiring volume data VD by transmitting a flat, fan-shaped transmission beam so as to spread perpendicularly to the ship's traveling direction, and integrating received signals in time series as the ship moves. may be used. Further, the volume data VD may be acquired by scanning a flat fan-shaped transmission beam similar to the above embodiment in the elevation/depression angle direction. Alternatively, the volume data VD may be acquired by transmitting an umbrella-shaped transmission beam all around the ship.

Further, in the above embodiment, the size of the measurement frame 55 is changed in a similar manner, but the shape of the measurement frame 55 itself, such as the aspect ratio of the measurement frame 55, may be changed according to the operation. For example, by moving the mouse 100 while clicking on the vertex of the measurement frame 55, the shape of the measurement frame 55 may be changed so as to stretch in the direction of movement of the mouse 100.

Further, the measurement method for the measurement frame 55 is not limited to the above embodiment, and other measurement methods that can appropriately indicate information regarding the density and number of fish schools included in the measurement frame 55 may be used. Information acquired for a school of fish can also be changed as appropriate.

Further, in the above embodiment and modification example 3, the detection image when viewed in the direction in which the cross-sectional image is moved is displayed on the cross-sectional image display screen, but the detected image displayed on the screen is the cross-sectional image. The detection image does not have to be a detection image when viewed in the moving direction, and may be a detection image from a normal viewpoint as shown in FIG. 6, for example.

Further, the cross-sectional image does not necessarily have to be displayed at the same time as the detected image; for example, only the cross-sectional image may be displayed on the display unit 19.

In addition, the embodiments of the present invention can be modified in various ways within the scope of the claims.

10 Underwater detection device 17 Signal processing section 18 Operation section 19 Display section 31, 41, 51 Detection image 45, 47a Cross-sectional image 46 Measurement frame (measurement position)
55 Measurement frame (measurement range)
56a Fish amount (information regarding fish amount)
56c Histogram 100 Mouse S1~S4 Slice plane VB Volume data

Claims (16)

Volume data indicating the distribution of signal strength of reflected waves in a three-dimensional detection range is sliced on a slice plane according to an operation on the operation unit, and the distribution of the signal strength is determined based on the volume data on the slice plane. a signal processing unit that causes a display unit to display a cross-sectional image shown in FIG.
An underwater detection device characterized by: The underwater detection device according to claim 1,
The signal processing unit generates a detection image showing the distribution of the signal intensity when viewed from a predetermined viewpoint based on the volume data, and displays the generated detection image on the display unit. . The underwater detection device according to claim 2,
The signal processing unit is an underwater detection device that displays the cross-sectional image superimposed on the detection image. The underwater detection device according to claim 3,
In the underwater detection device, the signal processing unit sets the detection image closer to the viewpoint than the slice plane of the cross-sectional image to non-display. The underwater detection device according to claim 3,
In the underwater detection device, the signal processing unit sets the detection image closer to the viewpoint than the slice plane of the cross-sectional image to a transparent display. The underwater detection device according to claim 2,
In the underwater detection device, the signal processing section causes the display section to display the cross-sectional image separately from the detection image. The underwater detection device according to any one of claims 1 to 6,
The signal processing unit is an underwater detection device that receives a selection of a moving direction of the slice plane via the operation unit. The underwater detection device according to any one of claims 1 to 7,
In the underwater detection device, the moving direction of the slice plane includes a vertical direction. The underwater detection device according to any one of claims 1 to 8,
The moving direction of the slice plane includes the line-of-sight direction. The underwater detection device according to any one of claims 1 to 9,
In the underwater detection device, the moving direction of the slice plane includes a horizontal direction. The underwater detection device according to any one of claims 1 to 10,
In the underwater detection device, the signal processing section sets a signal strength measurement position on the cross-sectional image in response to an operation on the operation section. The underwater detection device according to claim 11,
In the underwater detection device, the signal processing unit sets a predetermined three-dimensional range including the measurement position as a signal strength measurement range. The underwater detection device according to claim 12,
The signal processing unit generates a detection image showing the distribution of the signal strength when viewed from a predetermined viewpoint based on the volume data, displays the measurement range on the generated detection image, and performs the operation. An underwater detection device that changes the size of the measurement range according to an operation on the part. The underwater detection device according to claim 12 or 13,
In the underwater detection device, the signal processing section causes the display section to display a histogram of the signal strength included in the measurement range. The underwater detection device according to any one of claims 12 to 14,
In the underwater detection device, the signal processing section causes the display section to display information regarding the amount of fish included in the measurement range based on the signal strength included in the measurement range. Volume data indicating the distribution of signal strength of reflected waves in a three-dimensional detection range is sliced at slice planes according to operations on the operation unit,
A method for displaying an underwater detection image, comprising displaying a cross-sectional image showing the distribution of the signal intensity on a display unit based on the volume data on the slice plane.

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