Ultrasonic sonar device

Abstract

To provide an ultrasonic sonar device capable of grasping azimuth and depth of a spot where an object to detect exists.SOLUTION: An ultrasonic sonar device performs: top image generation processing which generates top image information representing a top image 22 that projects an underwater detection result onto a surface parallel to a horizontal surface on the basis of a reception signal caused by receiving reflection waves of ultrasonic beam transmitted by a vibrator and stores it to a RAM; and side image generation processing which generates side image information representing a side image 23 projecting the underwater detection result onto a surface vertical to the horizontal surface for indication. The ultrasonic sonar device displays the top image 22 corresponding to the top image information stored to the RAM to a display device 21 together with the side image 23 corresponding to the side image information.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic sonar device that is mounted on a ship and performs underwater detection over a predetermined range by rotating the azimuth angle of ultrasonic waves transmitted in the form of a beam. [Background technology]

[0002] Ultrasonic sonar devices, such as fish finders, are known as devices that detect underwater targets, such as schools of fish, by transmitting and receiving ultrasonic waves (see, for example, Patent Document 1). Ultrasonic sonar devices are configured to transmit (irradiate) a thin beam of ultrasonic waves from a transducer placed on the bottom of a ship, and the transducer receives the reflected waves of the beam of ultrasonic waves.

[0003] The ultrasonic sonar device has a mechanism that allows the depression and azimuth angles of the transducer that transmits and receives ultrasonic waves to be freely changed. For example, by setting the depression angle of the transducer and then changing the azimuth angle of the transducer, the ultrasonic sonar device sequentially transmits and receives ultrasonic waves while rotating the transducer at predetermined angles around the ship, thereby realizing a sonar function that detects underwater objects over a predetermined range. This sonar function transmits ultrasonic beams, receives reflected waves of the ultrasonic beams from the detection target, etc., and generates detection images as detection results from the received signals and displays them sequentially on a display device.

[0004] Conventional ultrasonic sonar devices display a top image shown from above the ship as the detection image, which allows users to see at a glance the direction of the detected object relative to the ship. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-023594 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the top image is displayed in two dimensions, so it does not contain depth information, making it difficult to grasp at a glance the depth at which the detected object is located.

[0007] SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an ultrasonic sonar device that can grasp both the direction and depth of a detection target. [Means for solving the problem]

[0008] In order to achieve this object, a first aspect of the present invention is an ultrasonic sonar device comprising: a transducer that transmits a beam of ultrasonic waves into water and is capable of receiving the reflected waves; depression angle setting means that sets the depression angle of the ultrasonic waves transmitted from the transducer; azimuth angle changing means that changes the azimuth angle of the ultrasonic waves transmitted from the transducer; control means that controls the depression angle setting means to set the depression angle of the ultrasonic waves to a predetermined depression angle, and then controls the azimuth angle changing means to rotate the azimuth angle of the ultrasonic waves over a predetermined range, thereby controlling the transducer to transmit and receive the ultrasonic waves sequentially; and The device is equipped with a top image generation means that generates top image information representing a top image showing the underwater detection results projected onto a plane parallel to the horizontal plane based on a received signal generated by receiving the reflected waves of the ultrasonic waves transmitted from the vibrator under control and stores the generated information in a storage means, a side image generation means that generates side image information representing a side image showing the underwater detection results projected onto a plane perpendicular to the horizontal plane and stores the generated information in a storage means, and a display means that displays the top image corresponding to the top image information stored in the storage means and the side image corresponding to the side image information together.

[0009] In a second aspect of the present invention, in the ultrasonic sonar device according to the first aspect, the side image generating means generates the side image information by performing coordinate transformation on the top image information generated by the top image generating means based on the predetermined depression angle.

[0010] In a third aspect of the present invention, in the ultrasonic sonar device according to the first aspect, the side of the predetermined range closer to the viewpoint of the side image is defined as a first range, and the side farther from the viewpoint is defined as a second range, and the side image generating means generates the side image information so that detection results included in the first range are represented in a first color and detection results included in the second range are represented in a second color different from the first color.

[0011] In a fourth aspect of the present invention, in the ultrasonic sonar device according to the first aspect, the side image generating means, each time receiving a reflected wave of the ultrasonic wave transmitted from the transducer under the control of the control means, overwrites the previous side image information at that position with new side image information to be displayed at a position corresponding to the newly received received signal and stores the new side image information in the memory means.

[0012] In a fifth aspect of the present invention, in the ultrasonic sonar device according to the first aspect, the side of the predetermined range closer to the viewpoint of the side image is defined as a first range, and the side farther from the viewpoint is defined as a second range, and each time the side image generating means receives a reflected wave of the ultrasonic wave transmitted from the transducer toward either the first range or the second range under the control of the control means, it overwrites the previous side image information of the position corresponding to the newly received received signal with new side image information to be displayed at that position and stores the new side image information in the storage means, and each time it receives a reflected wave of the ultrasonic wave transmitted from the transducer toward the other of the first range or the second range under the control of the control means, it overwrites the previous side image information of the position only with the side image information of the newly received received signal at a position where the intensity of the reflected wave is equal to or greater than a predetermined level and stores the new side image information in the storage means.

[0013] In a sixth aspect of the present invention, in the ultrasonic sonar device of the first aspect, the predetermined range is composed of a third range and a fourth range, and the side image generation means generates third range side image information representing a third range side image showing the underwater detection results included in the third range projected onto a plane perpendicular to the horizontal plane, and fourth range side image information representing a fourth range side image showing the underwater detection results included in the fourth range projected onto a plane perpendicular to the horizontal plane, and stores these in a memory means, and the display means displays the top image corresponding to the top image information stored in the memory means, the third range side image corresponding to the third range side image information, and the fourth range side image corresponding to the fourth range side image information together. [Effects of the Invention]

[0014] According to the ultrasonic sonar device of the first aspect of the present invention, under the control of the control means, the depression angle setting means sets the depression angle of the ultrasonic waves to a predetermined depression angle, and the azimuth angle changing means rotates the azimuth angle of the ultrasonic waves over a predetermined range, while the transducer transmits and receives ultrasonic beams. Based on the received signals generated by receiving the reflected waves of the ultrasonic waves, the top image generating means generates top image information representing a top image showing the underwater detection results projected onto a plane parallel to the horizontal plane and stores it in the storage means. The side image generating means also generates side image information representing side images showing the underwater detection results projected onto a plane perpendicular to the horizontal plane and stores it in the storage means. The top image corresponding to the top image information stored in the storage means and the side image corresponding to the side image information are then displayed together on the display means. This allows the user to determine the direction of the detection target from the top image and the depth at which the detection target is located from the side image displayed together. This provides the advantage of being able to simultaneously determine the direction and depth at which the detection target is located.

[0015] The ultrasonic sonar device according to the second aspect of the present invention has the following effect in addition to the effect of the ultrasonic sonar device according to the first aspect: Side screen information can be easily generated simply by converting the coordinates of the top image information using the depression angle.

[0016] The ultrasonic sonar device according to the third aspect of the present invention achieves the following effect in addition to the effect achieved by the ultrasonic sonar device according to the first aspect. Specifically, in the side image information generated by the side image information generating means, detection results included in a first range, which is within a predetermined range in which ultrasonic waves are transmitted and received and which is closer to the viewpoint of the side image, are displayed in a first color. Furthermore, in the side image information, detection results included in a second range, which is within the predetermined range and farther from the viewpoint of the side image, are displayed in a second color different from the first color. Because the side image does not provide information on the depth direction relative to the viewpoint, it is difficult to determine whether the displayed detection results are from the first range, which is closer to the viewpoint, or the second range, which is farther from the viewpoint. In contrast, by displaying the detection results for the first range in a first color and the detection results for the second range in a second color, the user can easily determine whether the displayed detection results are from the first range or the second range.

[0017] The ultrasonic sonar device according to the fourth aspect of the present invention achieves the following effect in addition to the effect achieved by the ultrasonic sonar device according to the first aspect. That is, each time a reflected wave of an ultrasonic wave transmitted from the transducer is received under the control of the control means, new side image information to be displayed at a position corresponding to the newly received received signal is overwritten by the side image generation means on the previous side image information at that position and stored in the storage means. This has the effect of always being able to display a side image based on the most recent detection result.

[0018] The ultrasonic sonar device according to the fifth aspect of the present invention achieves the following effect in addition to the effect achieved by the ultrasonic sonar device according to the first aspect. Specifically, under the control of the control means, each time a reflected wave of ultrasonic waves transmitted from the transducer toward either a first range, which is closer to the viewpoint of the side image, or a second range, which is farther from the viewpoint, is received, new side image information to be displayed at a position corresponding to the newly received received signal is overwritten by the side image generation means on previous side image information for that position and stored in the storage means. Meanwhile, under the control of the control means, each time a reflected wave of ultrasonic waves transmitted from the transducer toward the other of the first and second ranges is received, only new side image information to be displayed at a position corresponding to a newly received received signal whose reflected wave intensity is equal to or greater than a predetermined level is overwritten by the side image generation means on previous side image information for that position and stored in the storage means. This has the effect of allowing the newly detected detection results for the first and second ranges to be simultaneously displayed in the side image, while side images based on previous detection results for the predetermined range are sequentially erased.

[0019] The ultrasonic sonar device according to the sixth aspect of the present invention achieves the following effect in addition to the effect achieved by the ultrasonic sonar device according to the first aspect. Third range side image information representing a third range side image showing underwater detection results included in a third range of the predetermined ranges projected onto a plane perpendicular to the horizontal, and fourth range side image information representing a fourth range side image showing underwater detection results included in a fourth range of the predetermined ranges projected onto a plane perpendicular to the horizontal, are generated by side image generation means and stored in storage means. Then, a top image corresponding to the top image information stored in storage means, the third range side image corresponding to the third range side image information, and the fourth range side image corresponding to the fourth range side image information are displayed together on display means. In one side image, the detection results from the third range and the detection results from the fourth range are displayed in the same position, making it difficult to determine which range the detected object is included in, or only one range being displayed. However, the third range side image showing the underwater detection results included in the third range and the fourth range side image showing the underwater detection results included in the fourth range are displayed clearly separated, so the third range side image and the fourth range side image can clearly show not only the depth of the detected object, but also whether it is located in at least the third range or the fourth range. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic diagram illustrating the configuration of an ultrasonic sonar device according to a first embodiment of the present invention. [Figure 2] 1 is a schematic side view showing a state in which underwater detection is performed by a ship equipped with the ultrasonic sonar device. FIG. [Figure 3] FIG. 10 is a perspective schematic diagram illustrating the state when the detection is performed. [Figure 4] FIG. 2 is a cross-sectional view schematically showing a cross section of a wave transmitting and receiving unit of the ultrasonic sonar device. [Figure 5] FIG. 2 is a block diagram showing the electrical configuration of the ultrasonic sonar device. [Figure 6]10 is a flowchart showing sonar processing executed by a CPU of the ultrasonic sonar device. [Figure 7] 10A and 10B are diagrams for explaining coordinate conversion from top image information to side image information, which is performed in a side image generation process that is one process of the sonar process. [Figure 8] FIG. 2 is a diagram showing a simplified example of a display on a display device of the ultrasonic sonar device. [Figure 9] FIG. 10 is a diagram showing a side image displayed on a display device of the ultrasonic sonar device according to the second embodiment. [Figure 10] (a) is a diagram showing an example of a third range side image showing underwater detection results in the range behind the ship, and a fourth range side image showing the underwater detection range in the range forward of the ship, displayed on the display device of the ultrasonic sonar device of the third embodiment; (b) is a diagram showing another example of a third range side image showing underwater detection results in the range behind the ship, and a fourth range side image showing the underwater detection range in the range forward of the ship, displayed on the display device of the ultrasonic sonar device; and (c) is a diagram showing an example of a third range side image showing underwater detection results in the range port side of the ship, and a fourth range side image showing the underwater detection range in the range starboard side of the ship, displayed on the display device of the ultrasonic sonar device. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Each of the embodiments described below represents a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component placement positions, and connection configurations shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components that are not recited in the independent claims that represent the highest concept of the present invention will be described as optional components. Furthermore, in each drawing, substantially identical components are designated by the same reference numerals, and redundant descriptions will be omitted or simplified.

[0022] (First embodiment) First, an ultrasonic sonar device 1 according to a first embodiment of the present invention will be described with reference to Figures 1 to 8. Figure 1 is a schematic diagram showing the configuration of the ultrasonic sonar device 1 of this embodiment, Figure 2 is a schematic diagram showing a side view of the state when underwater detection is performed by a ship 71 equipped with the ultrasonic sonar device 1, and Figure 3 is a schematic perspective view of the state when the same detection is performed.

[0023] 1 to 3, the ultrasonic sonar device 1 is mounted on a ship 71 and has a sonar function for detecting a detection target GF, such as a school of fish, in the water over a predetermined range around the ship 71. The ultrasonic sonar device 1 also has one wave transmitting and receiving unit 51 (more specifically, a transducer 521 shown in FIG. 4), which will be described later, that is provided to realize the sonar function.

[0024] The ultrasonic sonar device 1 comprises a main body 11, an operation button 31 provided on the main body 11, a display device 21 integrally formed with the main body 11, a transmission / reception unit 51 for transmitting and receiving an ultrasonic beam TB, and an elevating device 41 for raising and lowering the transmission / reception unit 51.

[0025] The main body 11, operation buttons 31, and display device 21 are disposed in the wheelhouse of the ship 71, while the wave transmitting and receiving unit 51 and the lifting device 41 are disposed in the bottom of the ship 71. The wave transmitting and receiving unit 51 is raised and lowered by the lifting device 41, so that it can freely appear and disappear into the water from the bottom of the ship 71. The display device 21 corresponds to the display means of the present invention.

[0026] The operation button 31 is a button that can be operated by the user, and is operated when the user makes various settings for the ultrasonic sonar device 1. For example, the range to be detected underwater by the sonar function (hereinafter referred to as the "predetermined range"), the depression angle θ to be set when rotating the ultrasonic beam TB, etc. are set by the user using the operation button.

[0027] As shown in Figure 2, the ultrasonic sonar device 1 transmits (irradiates) a thin beam-shaped ultrasonic beam TB from the transmission and reception unit 51 in one direction while the transmission and reception unit 51 is protruding from the bottom of the ship 71, and receives the reflected waves of the ultrasonic beam TB reflected from the detection object GF, the seabed or lakebed (hereinafter collectively referred to as the "bottom"), etc., by the transmission and reception unit 51.

[0028] The wave transmitting and receiving unit 51 is configured by a full-circle sonar, and can change the azimuth angle δ (scan angle, see FIG. 3) and depression angle θ (tilt angle, see FIG. 2) of the ultrasonic beam TB transmitted and received by the wave transmitting and receiving unit 51.

[0029] Here, the azimuth angle δ (scan angle) is an angle that represents the transmission and reception direction of the ultrasonic beam TB when viewed from above the ship 71. In this embodiment, when the ship 71 is viewed from above, the azimuth angle δ is defined as 0 degrees when the ultrasonic beam TB is transmitted and received in the forward direction of the ship 71 (toward the bow), and the magnitude of the azimuth angle δ is defined so that the azimuth angle δ increases as the transmission and reception direction of the ultrasonic beam TB changes clockwise around the ship 71.

[0030] In addition, the depression angle θ (tilt angle) is the angle between the transmission and reception direction of the ultrasonic beam TB and the water surface (horizontal plane) on which the ship 71 floats, and the magnitude of the depression angle θ is defined so that the depression angle θ increases as the transmission and reception direction of the ultrasonic beam TB moves away from the water surface (horizontal plane) and points in a direction perpendicular to the water surface, with 0 degrees being the angle.

[0031] As shown in FIG. 3, the ultrasonic sonar device 1 sequentially transmits the ultrasonic beam TB at a predetermined feed angle over a predetermined range set by the user using the operation button 31 (in FIG. 3, the predetermined range is shown as the entire circumference), while rotating the azimuth angle δ, for example, clockwise (to the right), while keeping the depression angle θ of the transmission direction of the ultrasonic beam TB fixed at a set value.

[0032] The ultrasonic sonar device then performs underwater detection over a predetermined range by receiving reflected waves of the ultrasonic beams TB transmitted in each transmission direction. The underwater detection results are displayed on the display device 21 as a top image 22 formed based on the reception signals generated by receiving the reflected waves. The top image 22 is an image in which the underwater detection results are projected onto a plane parallel to the horizontal plane with the viewpoint set above the ship 71. In other words, the top image 22 can be said to be an image of the underwater detection results viewed from above the ship 71.

[0033] The ultrasonic sonar device 1 also generates side image information 63d (see FIG. 5), which is data for displaying the side image 23, based on top image information 63c (see FIG. 5), which is data for displaying the top image 22. Here, the side image 23 is an image projected onto a plane perpendicular to the horizontal plane, and the viewpoint is set in a direction perpendicular to the perpendicular plane. In this embodiment, a side image 23 is formed with the viewpoint set rearward relative to the front, rear, left, and right of the ship 71. The ultrasonic sonar device 1 displays this side image 23 together with the top image 22 on the display device 21. A method for generating the side image information will be described later.

[0034] Next, the detailed configuration of the wave transmitting and receiving unit 51 will be described with reference to Fig. 4. Fig. 4 is a cross-sectional view that schematically shows the cross section of the wave transmitting and receiving unit 51. The wave transmitting and receiving unit 51 is composed of a cylindrical lower case 511 with a bottom that is open at the top end and has a hemispherical lower end, a cylindrical upper case 512 with a lid that is open at the bottom end and has a disk-shaped upper end, and a disk-shaped lid 513 that closes the bottom opening of the upper case 512 and the top opening of the lower case 511. An upper storage space 514 is formed by the top surface of the lid 513 and the upper case 512, and a lower storage space 515 is formed by the bottom surface of the lid 513 and the lower case 511.

[0035] A through-hole 516 is formed in the center of the lid 513. A scan motor 517 formed by a stepping motor is fixed to the center of the top of the lid 513, and an output shaft of the scan motor 517 extends directly downward from the underside of the scan motor 517 while being rotatably inserted into the through-hole. The tip (lower end) of the output shaft reaches the top of the lower storage space 515.

[0036] A circular support plate 518 is provided at the tip of the output shaft, and the center of the upper surface of support plate 518 is connected to the tip of the output shaft. A roughly inverted U-shaped support frame 519 is provided on the lower surface of support plate 518, and a horizontally extending rotation shaft 520 is rotatably mounted between the lower ends of support frame 519.

[0037] Vibrator 521, which transmits a thin ultrasonic beam TB (see FIG. 2) in one direction and can receive the reflected wave of the transmitted ultrasonic beam TB, is fixed to the center of rotating shaft 520. Approximately semicircular tilt gear 522 is fixed to a position on rotating shaft 520 adjacent to vibrator 521, and rotating shaft 520, vibrator 521, and tilt gear 522 are configured to rotate integrally with one another.

[0038] Tilt motor 523, which is made up of a stepping motor, is fixed to the upper end of support frame 519. Tilt motor 523 has output shaft 524 extending toward tilt gear 522. Pinion gear 525 is provided at the tip of output shaft 524, and pinion gear 525 meshes with tilt gear 522.

[0039] When the scan motor 517 is driven, the output shaft of the scan motor 517 rotates, and as a result, the support plate 518, support frame 519, and rotating shaft 520 rotate together around the output shaft of the scan motor 517, causing the vibrator 521 fixed to the rotating shaft 520 to also rotate around the output shaft of the scan motor 517.

[0040] As a result, the transmission direction of the ultrasonic beam TB from the transducer 521 can be changed clockwise or counterclockwise when the water surface on which the ship 71 floats is viewed from above. That is, by driving the scan motor 517, the azimuth angle (scan angle) δ of the ultrasonic beam TB transmitted by the transducer 521 is changed.

[0041] On the other hand, when tilt motor 523 is driven, output shaft 524 rotates, which in turn rotates small gear 525, causing tilt gear 522 meshing with small gear 525 to rotate, causing rotating shaft 520 to which tilt gear 522 is fixed to rotate in accordance with the rotation of tilt gear 522, and vibrator 521 fixed to rotating shaft 520 to rotate around rotating shaft 520.

[0042] As a result, the depression angle (tilt angle) θ, which is the angle between the direction in which the transducer 521 is facing (the transmission direction of the ultrasonic beam TB transmitted from the transducer 521) and the water surface on which the ship 71 floats, is changed by driving the tilt motor 523.

[0043] Next, the electrical configuration of the ultrasonic sonar device 1 will be described with reference to Fig. 5. Fig. 5 is a block diagram showing the electrical configuration of the ultrasonic sonar device 1.

[0044] The main body of the ultrasonic sonar device 1 has a control device 6 which corresponds to the control means of the present invention. The control device 6 controls the operation of the ultrasonic sonar device 1. As shown in Fig. 5, the control device 6 has a CPU (Central Processing Unit) 61, a flash memory 62, and a RAM (Random Access Memory) 63, which are connected via a bus line.

[0045] The bus line is also connected to the above-mentioned operation button 31, display device 21, and lifting device 41. The above-mentioned scan motor 517 and tilt motor 523 are also connected to the bus line via a motor driver 65, and the vibrator 521 is connected to the bus line via a transmitting / receiving circuit 66.

[0046] The CPU 61 is a computing device that executes various calculations for controlling the operation of the ultrasonic sonar device 1 in accordance with program data 62 a stored in the flash memory 62 .

[0047] The flash memory 62 is a rewritable nonvolatile memory for storing program data 62a as well as fixed value data such as various setting values. The program data 62a may be stored in a separately prepared non-rewritable ROM instead of the flash memory.

[0048] The program data 62a includes, for example, a program that causes the CPU 61 to execute the sonar processing shown in Fig. 6. When this program is executed, the CPU 61 executes the program data 62a to raise and lower the wave transmitting and receiving unit 51 using the elevator device 41, set the depression angle θ of the ultrasonic beam TB by driving the tilt motor 523 via the motor driver 65, rotate the ultrasonic beam TB at an azimuth angle δ within a predetermined range by driving the scan motor 517 via the motor driver 65, transmit the ultrasonic beam TB by the transducer 521 via the transmitter / receiver circuit 66 and receive its reflected waves, and generate and display a top image 22 and a side image 23 showing underwater detection results based on the received signals. Details will be described later with reference to Fig. 6.

[0049] The program data 62a also includes a top image generation program 62a1 that causes the CPU 61 to execute a top image generation process, which is one of the processes in the sonar processing, and a side image generation program 62a2 that causes the CPU 61 to execute a side image generation process, which is also one of the processes in the sonar processing.

[0050] The top image generation program 62a1, when executed by the CPU 61, constitutes the top image generation means of the present invention, and is a program that generates top image information 63c, which is data for displaying a top image 22 showing underwater detection results on the display device 21, based on the received signal of the reflected wave of the ultrasonic beam TB received by the transducer 521, and stores the information in the RAM 63.

[0051] The side image generation program 62a2, when executed by the CPU 61, constitutes the side image generation means of the present invention, and is a program that executes a process of generating side image information 63d, which is data for displaying a side image 23 showing underwater detection results on the display device 21, based on the received signal of the reflected wave of the ultrasonic beam TB received by the transducer 521, and saving the generated side image information 63d in the RAM 63.

[0052] In addition, the program data 62a includes a program that determines, based on a signal input from the operation button 31, that the user has operated the operation button 31, and executes control in accordance with the operation of the operation button 31. For example, when various setting values are changed by operating the operation button 31, the program executes processes such as displaying a screen related to the setting change, accepting input of the changed setting values, and storing the changed setting values in the flash memory 62.

[0053] The various setting values stored in the flash memory 62 include setting values for setting a predetermined range for underwater detection in the sonar function.

[0054] In the sonar function, the set value for defining a predetermined range for underwater detection is set by the azimuth angle δ of the ultrasonic beam TB. For example, if the predetermined range is set to 45 degrees to 135 degrees, underwater detection within that range is performed by rotating the transmission direction of the ultrasonic beam TB within the azimuth angle range of 45 degrees to 135 degrees. If the predetermined range is set to 0 degrees to 0 degrees, the transmission direction of the ultrasonic beam TB is rotated within the full azimuth angle range. In other words, the ultrasonic beam TB is transmitted while rotating all around. This allows underwater detection to be performed all around the ship 71 (the wave transmitting and receiving unit 51).

[0055] The RAM 63 is a rewritable volatile memory that temporarily stores various data when the program data 62a is executed by the CPU 61. The RAM 63 corresponds to the storage means of the present invention, and stores the above-mentioned top image information 63c and side image information 63d, as well as at least azimuth angle data 63a and depression angle data 63b, for example.

[0056] The azimuth angle data 63a is the azimuth angle δ of the current transmission / reception direction of the ultrasonic beam TB.

[0057] The depression angle data 63b is a setting value for setting the depression angle θ in the transmission / reception direction of the ultrasonic beam TB in the sonar function. The depression angle data 63b stores the depression angle θ set by the user by operating the operation button 31. In the depression angle data 63b, the closer the value of the depression angle θ is set to 0 degrees, the wider the underwater detection range becomes, and the closer the value of the depression angle θ is set to 90 degrees, the narrower the underwater detection range becomes directly below the ship 71.

[0058] In the sonar function, the direction of transmission and reception of the ultrasonic beam TB is such that the azimuth angle δ changes sequentially while the depression angle θ is fixed at the angle set in the depression angle data 63b. The azimuth angle δ of the ultrasonic beam TB currently being transmitted and received is stored in the azimuth angle data 63a.

[0059] The depression angle data 63b may be stored in the flash memory 62 instead of the RAM 63.

[0060] The contents of the top image information 63c and the side image information 63d are as described above, but when the CPU 61 starts sonar processing to realize the sonar function, the top image and side image are initialized with the color information so that they are displayed in the color that is displayed when the intensity level of the reflected wave of the ultrasonic beam TB is 0.

[0061] Based on the output signal from the CPU 61, the motor driver 65 transmits a step control signal for operating the scan motor 517 or tilt motor 523 of the wave transmitting and receiving unit 51. The scan motor 517 and tilt motor 523 are driven based on this step control signal, causing the vibrator 521 to rotate.

[0062] The transmission / reception circuit 66 is a circuit for controlling the transmission and reception of the ultrasonic beam TB in the transducer 521. The transmission / reception circuit 66 transmits a drive signal to the transducer 521 based on an output signal from the CPU 61, and controls the transducer 521 to transmit the ultrasonic beam TB based on the drive signal. The transmission / reception circuit 66 also receives and outputs a reception signal (analog signal) of the ultrasonic beam TB transmitted by the transducer 521, the reflected wave of which is reflected from a detection target GF, the bottom of the water, etc., and converts the reception signal (digital signal) into a digital signal, and transmits the reception signal (digital signal) to the control device 6. The control device 6 temporarily stores the reception signal (digital signal) in the RAM 63, and then generates top image information 63c for displaying the top image 22 based on the reception signal (digital signal).

[0063] Next, referring to Fig. 6, the main processing executed by the CPU 61 to realize the functions of the ultrasonic sonar device 1 will be described. Fig. 6 is a flowchart showing the sonar processing executed by the CPU 61. The sonar processing is processing executed when the ultrasonic sonar device 1 performs the sonar function. Note that the description here is based on the assumption that the setting value of the predetermined range for underwater detection in the sonar function is set to 0 degrees to 0 degrees, i.e., the entire circumference.

[0064] When the CPU 61 executes sonar processing, it first drives the elevator device 41 to lower the wave transmitting and receiving unit 51 (S11). This causes the wave transmitting and receiving unit 51 to protrude into the water from the bottom of the ship 71, enabling the transducer 521 to transmit and receive the ultrasonic beam TB.

[0065] Next, the CPU 61 reads out the depression angle data 63b set by the user, and transmits a motor position signal to the motor driver 65 so that the depression angle θ of the ultrasonic beam TB becomes the depression angle θ indicated by the depression angle data 63b (S12). As a result, the tilt motor 523 of the wave transmitting and receiving unit 51 is driven by the motor driver 65, and the ultrasonic beam TB transmitted and received by the transducer 521 is set to have the depression angle θ. The processing of S12 corresponds to the depression angle setting means of the present invention.

[0066] Next, the CPU 61 updates the azimuth angle δ of the ultrasonic beam TB (S13). Specifically, when the CPU 61 executes the process of S13 for the first time since starting sonar processing, it initializes the value of the azimuth angle data 63a to 0°. In other cases, the CPU 61 adds a predetermined feed angle (for example, 1°) to the value stored in the azimuth angle data 63a and stores the added value in the azimuth angle data 63a. The CPU 61 then transmits a motor position signal to the motor driver 65 so that the azimuth angle δ of the ultrasonic beam TB becomes the azimuth angle δ indicated by the updated (initialized or added) azimuth angle data 63a. This causes the motor driver 65 to drive the scan motor 517 of the wave transmitting and receiving unit 51, and the ultrasonic beam TB transmitted and received by the transducer 521 is updated to have the azimuth angle δ. This process of S13 corresponds to the azimuth angle changing means of the present invention.

[0067] Next, the CPU 61 transmits and receives the ultrasonic beam TB (S14). Specifically, the CPU 61 transmits a control signal to the transmission / reception circuit 66 to cause the transducer 521 to transmit the ultrasonic beam TB. The transmission / reception circuit 66 drives the transducer 521 based on this control signal, causing the transducer 521 to transmit the ultrasonic beam TB. At this time, the orientation of the transducer 521 has been set to the direction of depression angle θ by the processing of S12, and has been updated to the direction of azimuth angle δ by the processing of S13, so the ultrasonic beam TB is transmitted in the direction of depression angle θ and azimuth angle δ.

[0068] The ultrasonic beam TB transmitted from the transducer 521 is reflected by the detection target GF, the water bottom, etc., and the reflected wave is received by the transducer 521. The received signal (analog signal) is input from the transducer 521 to the transmission / reception circuit 66 and converted into a digital signal by the transmission / reception circuit 66. The converted digital received signal is temporarily stored in the RAM 63.

[0069] When the reception signal (digital signal) of the reflected wave received by the transducer 521 is stored in the RAM 63, the CPU 61 then executes the top image generation program 62a1 and performs top image generation processing (S15). In the top image generation processing, top image information 63c for displaying the top image 22 is generated based on the reception signal stored in the RAM 63. Specifically, based on the reception signal stored in the RAM 63, a color corresponding to the intensity level of the reflected wave from each depth in the direction in which the ultrasonic beam TB is transmitted and received is determined from the first color, and the determined color information is overwritten in the top image information 63c at the coordinates of the top image corresponding to the position where the reflected wave is reflected. This allows the latest underwater detection results obtained by transmitting and receiving the ultrasonic beam TB to be reflected in the top image 22.

[0070] Next, the CPU 61 executes the side image generation program 62a2 to execute a side image generation process (S16). In the side image generation process, the top image information 63c newly generated in the top image generation process (S15) is subjected to coordinate conversion based on the depression angle θ set in the depression angle data 63b, thereby generating side image information 63d for displaying the side image 23.

[0071] Here, a method of coordinate conversion from top image information 63c to side image information 63d will be described with reference to Fig. 7. Fig. 7 is a diagram for explaining this coordinate conversion, with (a) showing top image 22 and (b) showing side image 23. For convenience, in the following description and Fig. 7, azimuth angle δ is converted to angle α (= δ - 180°), and depression angle θ is converted to angle β (= 90° - θ).

[0072] In Figure 7(a), the line segment LT shows the position of the top image 22 (i.e., the position in the top image 22 detected by the transmission and reception of the ultrasonic beam TB) for which new top image information 63c was generated by the top image generation process of S15 based on the underwater detection results using the ultrasonic beam TB transmitted and received in the direction of angle α (azimuth angle δ) and angle β (depression angle θ) by the processing of S14.

[0073] The side image generation process identifies the position in the side image 23 that the line segment LT in the top image 22 corresponds to. In Fig. 7(b), the position in the side image 23 that corresponds to the line segment LT in the top image 22 is indicated by the line segment LS. That is, the line segment LS indicates the position in the side image 23 that was detected by transmitting and receiving the ultrasonic beam TB in the directions of angle α (azimuth angle δ) and angle β (depression angle θ).

[0074] The line segment LS is identified by calculating the angle X shown in FIG. 7(b) and the range value RM at that angle X. The angle X is the angle when the direction of the ultrasonic beam TB transmitted and received at the angle α (azimuth angle δ) and the angle β (depression angle θ) is shown in the side image 23. The range value RM is the length of the detection range of the ultrasonic beam TB transmitted and received at the angle α (azimuth angle δ) and the angle β (depression angle θ) when displayed in the side image 23. The range value in the top image 22 (the length of the detection range of the ultrasonic beam TB when displayed in the top image 22) is not limited to the angle α (azimuth angle δ) and is constant at the radius r shown in FIG. 7(a). On the other hand, the range value RM becomes the maximum range value RA when the angle α is −90° or 90° (the azimuth angle δ is 90° or 180°), i.e., when the ultrasonic beam TB is transmitted and received so as to travel straight within the plane of the side image 23. That is, the range value RM takes a value equal to or less than the maximum range value RA.

[0075] The angle X can be calculated as follows: First, the radius r, which is the range value in the top image 22, and the maximum range value RA in the side image 23 have the relationship of the following equation (1) from FIG. 7(b).

[0076] r=RA·sinβ …(1) On the other hand, the minimum range value RB, which is the minimum value of the range values in the side image 23, occurs when the angle α is 0 or -180° (the azimuth angle δ is 180° or 0°), and the angle formed between the maximum and minimum range values in the side image 23 coincides with the angle β. Therefore, from FIG. 7(b), the minimum range value RB and the maximum range value RA have the relationship shown in the following equation (2).

[0077] RB=RA·cosβ …(2) Furthermore, the length x shown in the top image 22 in FIG. 7(a) and the side image 23 in FIG. 7(b) is expressed by the following equation (3) from FIG. 7(a) and equation (1).

[0078] x=r·sinα =RA·sinα·sinβ···(3) From FIG. 7(b) and equations (2) and (3), the angle X is expressed by the following equation (4).

[0079] X=tan -1 (x / RB) =tan -1 (RA sinα sinβ / RA cosβ) =tan -1 (sinα·sinβ / cosβ)…(4) Furthermore, the range value RM at the angle X can be expressed by the following equation (5) from FIG. 7(b) and equations (2) and (4).

[0080] RM=RB / cosX =RA·cosβ / cos(tan -1 (sinα·sinβ / cosβ))…(5) The side image generation process first expands the top image information 63c (color information) corresponding to the line segment LT of the top image 22 to the maximum range value range of the side image 23, and then reduces it to the range value range of the line segment LS. The side image generation process then expands the obtained color information to the position of the line segment LS represented by the angle X, and stores this as side image information 63d in RAM 63 as a detection result obtained by new detection.

[0081] In the side image generation process of this embodiment, all color information at the position of the line segment LS obtained by coordinate transformation is overwritten onto previous color information at the corresponding position, and this is saved as new side image information 63d in RAM 63. This allows the ultrasonic sonar device 1 to always display on the display device 21 a side image 23 based on the most recent underwater detection results.

[0082] Furthermore, in the side image generation process of this embodiment, when the bottom half of the top image 22 is transformed into the side image 23, that is, when the ultrasonic beam TB is transmitted and received on the rear side of the ship 71 (in this embodiment, the viewpoint of the side image 23 is set on the rear side of the ship 71, and this is the side close to that viewpoint; that is, this corresponds to the first range of the present invention), the color information on the line segment LS uses the color information associated with the line segment LT before the coordinate transformation as is. That is, in this case, the side image 23 on the line segment LS is expressed in the first color used in the top image 22.

[0083] On the other hand, in the side image generation process of this embodiment, when the top image 22 is converted into the side image 23 from the upper half side, i.e., when the ultrasonic beam TB is transmitted and received forward relative to the ship 71 (the side farther from the viewpoint of the side image 23, which corresponds to the second range of the present invention), the color information of the line segment LS is converted from the color information associated with the line segment LT before the coordinate conversion into different color information in a one-to-one relationship with that color information. This different color information represents a second color different from the first color. For example, the second color used is a color that is lighter than the first color.

[0084] The side image 23 is a two-dimensional image and does not have information about the depth direction relative to the viewpoint, making it difficult to determine whether the displayed underwater detection results are from the rear side of the ship 71, which is closer to the viewpoint, or from the front side of the ship 71, which is farther from the viewpoint. In contrast, by displaying the underwater detection results behind the ship 71 in a first color and the underwater detection results ahead of the ship 71 in a second color, the user can easily determine whether the displayed underwater detection results are from the rear side or the front side of the ship 71.

[0085] Next, we will return to Fig. 6 to continue the explanation of the sonar processing. When the CPU 61 completes the side image generation process (S16), it displays both the top image 22 based on the top image information 63c and the side image 23 based on the side image information on the display device 21 (S17), as shown in Fig. 8. Fig. 8 is a simplified diagram showing an example of a display on the display device 21 of the ultrasonic sonar device 1 according to this embodiment.

[0086] In this way, the ultrasonic sonar device 1 displays the underwater detection results using the ultrasonic beam TB on the display device 21 not only as the top image 22 but also as the side image 23. This allows the user of the ultrasonic sonar device 1 to determine the direction in which the detection target GF is located from the top image 22, and also to determine the depth at which the detection target GF is located from the side image 23 that is also displayed. Therefore, the direction and depth at which the detection target GF is located can be determined together.

[0087] Next, the CPU 61 determines whether the termination condition for the sonar function is met (S18), and if the termination condition is not met (S18: No), the process returns to S13. Then, in the process of S13, the azimuth angle δ of the ultrasonic beam TB is updated so as to advance by a predetermined feed angle, and the CPU 61 again executes the processes of S14 to S18. The CPU 61 repeatedly executes the processes of S13 to S18 until the termination condition for the sonar function is met.

[0088] If the CPU 61 determines in S18 that the condition for terminating the sonar function is met (S18: Yes), it terminates the sonar process. Examples of conditions for terminating the sonar function include when the user operates the operation button 31 to instruct the sonar function to be stopped, or when the user instructs the ultrasonic sonar device 1 to be powered off.

[0089] The ultrasonic sonar device 1 according to the first embodiment described above has the following advantages. Specifically, under the control of the CPU 61, the tilt motor 523 sets the depression angle θ of the ultrasonic beam TB to the depression angle θ indicated by the depression angle data 63b, and the scan motor 517 rotates the azimuth angle δ of the ultrasonic beam TB over a predetermined range, while the transducer 521 transmits and receives the beam-like ultrasonic beam TB. Based on a reception signal generated by receiving the reflected wave of the ultrasonic beam TB, top image information 63c representing a top image 22 showing the underwater detection results projected onto a plane parallel to the horizontal plane is generated by a top image generation process (S15) and stored in the RAM 63. Furthermore, side image information 63d representing a side image 23 showing the underwater detection results projected onto a plane perpendicular to the horizontal plane is generated by a side image generation process (S16) and stored in the RAM 63. Then, the top image 22 corresponding to the top image information 63c stored in the RAM 63 and the side image 23 corresponding to the side image information 63d are displayed together on the display device 21. This allows the user to grasp the direction in which the detection target GF exists from the top image 22, and the depth at which the detection target GF exists from the side image 23 that is also displayed. Therefore, the direction and depth at which the detection target GF exists can be grasped together.

[0090] (Second embodiment) Next, the operation of the ultrasonic sonar device 1 according to the second embodiment of the present invention will be described with reference to Fig. 9. Fig. 9 is a diagram showing a side image 23 displayed on the display device 21 of the ultrasonic sonar device 1 according to the second embodiment. Note that Fig. 9 does not show the top image 22, but the ultrasonic sonar device 1 according to the second embodiment also displays both the top image 22 and the side image 23 on the display device 21.

[0091] In the ultrasonic sonar device 1 according to the first embodiment, in the side image generation process (S16) executed each time an ultrasonic beam TB is transmitted or received, all color information at the position of the line segment LS obtained by coordinate transformation is overwritten over previous color information at the corresponding position, and this is stored as new side image information 63d in the RAM 63. In this case, the most recent underwater detection result is always displayed on the side image 23. However, since the side image 23 is a two-dimensional image and does not have depth information relative to the viewpoint, the underwater detection result (rear-side detection result) when the ultrasonic beam TB is transmitted or received behind the vessel 71 (first range of the present invention) and the underwater detection result (front-side detection result) when the ultrasonic beam TB is transmitted or received ahead of the vessel 71 (second range of the present invention) are displayed in the same position. Therefore, even if the side image 23 according to the first embodiment displays a rear-side detection result based on a rear-side detection, the rear-side detection result is sequentially erased by the display of a front-side detection result based on a subsequent front-side detection.

[0092] In contrast, the ultrasonic sonar device 1 according to the second embodiment updates the side image information 63d in the side image generation process (S16) as follows: When the bottom half of the top image 22 is converted into the side image 23, that is, when the ultrasonic beam TB is transmitted and received rearward (first range of the present invention) relative to the ship 71, the color information at the position of the line segment LS is overwritten on the previous color information at the corresponding position, and this is saved in the RAM 63 as new side image information 63d.

[0093] On the other hand, when the top image 22 is converted into the side image 23, that is, when the ultrasonic beam TB is transmitted and received forward of the ship 71 (the second range of the present invention), instead of overwriting all of the color information at the position of the line segment LS with the past color information at the corresponding position, only the color information at the position of the line segment LS where the intensity level of the reflected wave is above a predetermined level is overwritten with the past color information at the corresponding position, assuming that the detected object GF was at the depth corresponding to that position, and this is saved in RAM 63 as new side image information 63d.

[0094] As a result, when rearward detection is performed, the side image 23 displays new rearward detection results while past underwater detection results are sequentially erased, and when forward detection is subsequently performed, new frontward detection results can also be displayed in the side image 23 at positions where it is estimated that there was no reflection from the detection target GF, while the rearward detection results remain at positions where it is estimated that there was no reflection from the detection target GF. Therefore, the newly detected rearward detection results and frontward detection results can be displayed simultaneously in the side image 23.

[0095] In this case, by setting the color indicating the rear side detection result in the side image 23 to a first color and the color indicating the front side detection result to a second color different from the first color, even if the rear side detection result and the front side detection result are displayed simultaneously in the side image 23, the user can tell at a glance whether the underwater detection result is due to a rear side detection or a front side detection.

[0096] In the side image generation process (S16), when the ultrasonic beam TB is transmitted and received forward of the vessel 71 (second range of the present invention), color information at the position of the line segment LS is overwritten on previous color information at the corresponding position, and this is stored as new side image information 63d in the RAM 63. When the ultrasonic beam TB is transmitted and received backward of the vessel 71 (first range of the present invention), only color information at a position where the intensity level of the reflected wave is equal to or higher than a predetermined level among the color information at the position of the line segment LS may be overwritten on previous color information at the corresponding position, and this may be stored as new side image information 63d in the RAM 63. In this way, when forward detection is performed, previous underwater detection results are sequentially erased from the side image 23, and a new side image 23 based on the forward detection result is displayed. When a subsequent rearward detection is performed, the forward detection result remains at a position where it is estimated that there was no reflection from the detection target GF, and new rearward detection results can also be displayed in the side image 23 at a position where it is estimated that there was reflection from the detection target GF. Therefore, in this case as well, the newly detected front side detection result and rear side detection result can be displayed simultaneously on the side image 23.

[0097] (Third embodiment) Next, an ultrasonic sonar device 1 according to a third embodiment of the present invention will be described with reference to FIG.

[0098] The ultrasonic sonar devices 1 according to the first and second embodiments have been described with reference to the case where one side image 23 is displayed on the display device 21. In contrast, the ultrasonic sonar device 1 according to the third embodiment divides the predetermined range for transmitting and receiving the ultrasonic beam TB into two ranges, a third range and a fourth range, and displays third range side images 23a and 23c showing the third range detection results based on the transmission and reception of the ultrasonic beam TB in the third range, and fourth range side images 23b and 23d showing the fourth range detection results based on the transmission and reception of the ultrasonic beam TB in the fourth range, on the display device 21. Third range side image information for displaying the third range side images 23a and 23c and fourth range side image information for displaying the fourth range side images 23b and 23d are stored in the RAM 23.

[0099] Note that, like FIG. 9, none of the figures in FIGS. 10(a) to (c) show the top image 22, but in all cases, the third range side images 23a, 23c and the fourth range side images 23b, 23d are displayed on the display device 21 together with the top image 22.

[0100] 10(a) is a diagram showing the third range side image 23a and the fourth range side image 23b when the side image 23 showing the underwater detection result when the ultrasonic beam TB is transmitted and received within the predetermined range, with the range behind the ship 71 as the third range, is the third range side image 23a, and the side image 23 showing the underwater detection result when the ultrasonic beam TB is transmitted and received within the predetermined range, with the range ahead of the ship 71 as the fourth range side image 23b, is the fourth range side image 23b, when displayed on the display device 21. In FIG. 10(a), the viewpoint of the third range side image 23a and the viewpoint of the fourth range side image 23b are both set behind the ship 71.

[0101] In this case, the ultrasonic sonar device 1 converts the lower half of the top image 22 into a third range side image 23a in the side image generation process (S16) and generates third range side image information from the top image information 63c. That is, when the ultrasonic beam TB is transmitted and received in the range (third range) behind the ship 71, the color information at the position of the line segment LS, which is coordinate-transformed from the line segment LT in the top image 22 showing the underwater detection result, is overwritten on the previous color information at the corresponding position, and this is saved in the RAM 63 as new third range side image information.

[0102] On the other hand, the side image generation process (S16) converts the upper half of the top image 22 into a fourth range side image 23b and generates fourth range side image information from the top image information 63c. That is, when an ultrasonic beam TB is transmitted and received in the range (fourth range) forward of the ship 71, color information at the position of a line segment LS, which is coordinate-transformed from the line segment LT in the top image 22 showing the underwater detection result, is overwritten on the previous color information at the corresponding position, and this is saved in the RAM 63 as new fourth range side image information.

[0103] As a result, the top image 22 corresponding to the top image information 63c stored in RAM 63, the third range side image 23a corresponding to the third range side image information, and the fourth range side image 23b corresponding to the fourth range side image information are all displayed together on the display device 21. In one side image 23, the underwater detection results from the third range and the underwater detection results from the fourth range are displayed in the same position, making it difficult to determine which range the detection target GF is included in, or only one of the ranges being displayed. However, in this embodiment, the third range side image 23a showing the underwater detection results included in the third range and the fourth range side image 23b showing the underwater detection results included in the fourth range are displayed clearly separated from each other. Therefore, the third range side image 23a and the fourth range side image 23b can clearly indicate not only the depth of the detection target GF but also whether it is present in at least the third range or the fourth range.

[0104] 10(b) is a diagram showing the third range side image 23a and the fourth range side image 23b when the fourth range side image 23b in FIG. 10(a) is turned upside down and displayed on the display device 21. In this case, the viewpoint of the third range side image 23a is set behind the ship 71, while the viewpoint of the fourth range side image 23b is set in front of the ship 71.

[0105] In this case, the ultrasonic sonar device 1 operates in the same manner as in the case of Fig. 10(a), except that the fourth range side image 23b is upside down compared to the fourth range side image 23b in Fig. 10(a), thereby achieving the same effects as in the case of Fig. 10(a).

[0106] 10(c) is a diagram showing a third range side image 23c and a fourth range side image 23d when the side image 23 showing the underwater detection result when the ultrasonic beam TB is transmitted and received within the predetermined range, with the range on the port side of the ship 71 as the third range, is a third range side image 23c, and the side image 23 showing the underwater detection result when the ultrasonic beam TB is transmitted and received within the predetermined range, with the range on the starboard side of the ship 71 as the fourth range, is a fourth range side image 23d, when displayed on the display device 21. In FIG. 10(c), the viewpoint of the third range side image 23c is set on the port side of the ship 71, and the viewpoint of the fourth range side image 23b is set on the starboard side of the ship 71.

[0107] In this case, the ultrasonic sonar device 1 converts the left half of the top image 22 into a third range side image 23c in the side image generation process (S16) and generates third range side image information from the top image information 63c. That is, when an ultrasonic beam TB is transmitted and received to the port side range (third range) of the ship 71, color information at the position of a line segment LS, which is coordinate-transformed from the line segment LT of the top image 22 showing the underwater detection result, is overwritten on the previous color information at the corresponding position, and this is saved in the RAM 63 as new third range side image information.

[0108] On the other hand, the side image generation process (S16) converts the right half of the top image 22 into a fourth range side image 23b and generates fourth range side image information from the top image information 63c. That is, when an ultrasonic beam TB is transmitted and received in the range (fourth range) on the starboard side of the ship 71, color information at the position of a line segment LS, which is coordinate-transformed from the line segment LT of the top image 22 showing the underwater detection result, is overwritten on the previous color information at the corresponding position, and this is saved in the RAM 63 as new fourth range side image information.

[0109] As a result, although the third and fourth ranges are different from those in the cases of FIGS. 10(a) and 10(b), the case of FIG. 10(c) also achieves the same effects as those in FIGS. 10(a) and 10(b).

[0110] Although the present invention has been described above based on the embodiments, it is readily apparent that the present invention is not limited to the above embodiments, and various improvements and modifications are possible within the scope of the present invention. For example, each embodiment may be modified by adding or replacing a part or parts of the configuration of another embodiment, including the modifications described below. Furthermore, the numerical values given in the above embodiments are merely examples, and other numerical values may of course be adopted.

[0111] In the above embodiment, the case where the side image 23 is generated from the top image 22 using coordinate transformation has been described, but the side image 23 may also be generated using a received signal that is a reflected wave of the ultrasonic beam TB and that has been converted into a digital signal.

[0112] In the ultrasonic sonar device 1 of the first and second embodiments described above, the rear-side detection result is represented in a first color in the side image 23, and the front-side detection result is represented in a second color different from the first color, but the side image 23 may also be one in which the rear-side detection result and the front-side detection result are represented in the same color.

[0113] Furthermore, in the ultrasonic sonar device 1 of each of the above embodiments, the color (at least the first color) used to display the side image 23 is the same as the color used to display the top image 22, but it may be different from the color used to display the top image 22. For example, the color (first color) used to display the side image 23 may be darker than the color used to display the top image 22. In this case, the second color used to display the side image 23 may be the same as or different from the color used to display the top image 22. In either case, the first color and second color used in the side image 23 may be different. [Explanation of symbols]

[0114] 1. Ultrasonic sonar device 6 Control device (control means) 21 Display device (display means) 22 Top Images 23 Side image 23a Third Range Side Image 23b 4th range side image 23c Third Range Side Image 23d 4th range side image 62a1 Top image generation program (top image generation means) 62a2 Side image generation program (side image generation means) 63 RAM (memory means) 63a Azimuth data 63b Depression data 63c Top image information 63d side image information 65 Motor Driver 66 Transmitting and receiving circuit 71 Ship 517 Scan Motor 521 Oscillator 523 Tilt Motor GF Detected object TB Ultrasonic Beam

Claims

1. A transducer that transmits a beam of ultrasonic waves into water and receives the reflected waves; a depression angle setting means for setting the depression angle of the ultrasonic wave transmitted from the transducer; An azimuth angle changing means for changing the azimuth angle of the ultrasonic wave transmitted from the transducer; a control means for controlling the depression angle setting means to set the depression angle of the ultrasonic waves to a predetermined depression angle, and controlling the azimuth angle changing means to rotate the azimuth angle of the ultrasonic waves over a predetermined range, while controlling the transducer to sequentially transmit and receive the ultrasonic waves; a top image generating means for generating top image information representing a top image showing the underwater detection results projected onto a plane parallel to the horizontal plane based on a reception signal generated by receiving the reflected waves of the ultrasonic waves transmitted from the transducer under the control of the control means, and storing the generated top image information in a storage means; a side image generating means for generating side image information representing a side image that shows the underwater detection result projected onto a plane perpendicular to the horizontal plane, and storing the side image information in a storage means; An ultrasonic sonar device characterized by comprising a display means for displaying the top image corresponding to the top image information stored in the memory means and the side image corresponding to the side image information together.

2. 2. The ultrasonic sonar device according to claim 1, wherein the side image generating means generates the side image information by performing coordinate transformation on the top image information generated by the top image generating means based on the predetermined depression angle.

3. 2. The ultrasonic sonar device according to claim 1, wherein the side of the predetermined range closer to the viewpoint of the side image is defined as a first range and the side farther from the viewpoint is defined as a second range, and the side image generating means generates the side image information so that detection results included in the first range are represented in a first color and detection results included in the second range are represented in a second color different from the first color.

4. 2. The ultrasonic sonar device according to claim 1, wherein the side image generating means, each time receiving a reflected wave of the ultrasonic wave transmitted from the transducer under the control of the control means, overwrites the previous side image information at that position with new side image information to be displayed at a position corresponding to the newly received received signal and stores the new side image information in the storage means.

5. A side of the predetermined range that is closer to the viewpoint of the side image is defined as a first range, and a side that is farther from the viewpoint is defined as a second range, each time the side image generating means receives a reflected wave of the ultrasonic wave transmitted from the transducer toward either the first range or the second range under the control of the control means, the side image generating means overwrites the previous side image information at that position with new side image information to be displayed at a position corresponding to the newly received received signal, and stores the new side image information in the storage means; 2. The ultrasonic sonar device according to claim 1, wherein, each time a reflected wave of the ultrasonic wave transmitted from the transducer toward either the first range or the second range under the control of the control means is received, only the side image information of a position where the intensity of the reflected wave is equal to or greater than a predetermined level is overwritten on the previous side image information of that position and stored in the memory means.

6. Assuming that the predetermined range is composed of a third range and a fourth range, the side image generating means generates third range side image information representing a third range side image in which the underwater detection results included in the third range are projected onto a plane perpendicular to the horizontal plane, and fourth range side image information representing a fourth range side image in which the underwater detection results included in the fourth range are projected onto a plane perpendicular to the horizontal plane, and stores the information in a storage means; The ultrasonic sonar device according to claim 1, characterized in that the display means displays the top image corresponding to the top image information stored in the memory means, the third range side image corresponding to the third range side image information, and the fourth range side image corresponding to the fourth range side image information.

Images