Ultrasonic sonar device

Abstract

The ultrasonic sonar device 1 has detection result image generation means 16 that generates a horizontal detection result image 22 by projecting a detection result 22a in water onto a plane parallel to the horizontal plane based on a reception signal of a reflected wave of the ultrasonic wave TB reflected from at least a direction set in the azimuth direction. The detection result image generation means 16 generates the horizontal detection result image 22 so as to show a vertical detection result 22b based on a reception signal of a reflected wave of the ultrasonic wave TB reflected from the vertical direction in a region in a part of the azimuth direction in the horizontal detection result image 22, instead of the detection result 22a in water projected onto a plane parallel to the horizontal plane.

Description

Technical Field

[0001] The present invention relates to an ultrasonic sonar device mounted on a ship and performing underwater detection over a predetermined range around the ship.

Background Art

[0002] An ultrasonic sonar device that detects a detection target such as a fish school over a predetermined range in water by transmitting and receiving ultrasonic waves is known. A general fish school detection device detects a detection target in the vertical direction from a ship, while an ultrasonic sonar device can detect a detection target existing around the ship such as horizontal detection and vertical cross-section detection. As the ultrasonic sonar device, for example, a PPI sonar (searchlight sonar) and a scanning sonar are known.

[0003] The PPI sonar irradiates (transmits) a thin beam-shaped ultrasonic wave, and a vibrator that receives a reflected wave from the ultrasonic wave's detection target or the like is configured to be rotatable or pivotable, and performs underwater detection around the ship while changing the irradiation direction of the ultrasonic wave (for example, Patent Document 1). Since the structure of the vibrator of the PPI sonar is simple, it can be configured at low cost, but it takes time until one detection over a predetermined range is completed.

[0004] The scanning sonar forms a plurality of fine vibrators in an array shape on the surface of a cylinder, a sphere, or the like, transmits ultrasonic waves simultaneously from each vibrator, and receives the reflected waves to perform underwater detection around the ship at once (for example, Patent Document 2). The scanning sonar can perform one detection over a predetermined range in a short time, but on the other hand, the vibrator array becomes complicated, and the transmission and reception circuits for transmitting and receiving ultrasonic waves in each vibrator become large-scale, so it becomes expensive.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] When performing horizontal detection in such an ultrasonic sonar device, the transmission and reception directions of ultrasonic waves are generally set in a plurality of directions within a predetermined range with respect to the azimuth direction while being fixed at a predetermined depression angle. That is, horizontal detection in an ultrasonic sonar device generally involves detection from a ship obliquely downward.

[0007] On the other hand, the ultrasonic sonar device displays the detection result of horizontal detection as a circular image projected onto a plane parallel to the horizontal plane. This image can easily show the user the presence or absence of detection targets such as fish schools within a predetermined range, the direction in which the detection target exists, and the position at which the detection target exists at what distance from the ship in the horizontal direction. However, since the image is a projection of the detection result onto a plane parallel to the horizontal plane as described above, there is a problem that it is difficult for the user to intuitively grasp the depth at which the detection target exists.

[0008] The present invention has been made to solve the above problems, and an object thereof is to provide an ultrasonic sonar device that can intuitively grasp the depth of a detection target in horizontal detection. [Means for Solving the Problems]

[0009] To achieve this object, a first aspect of the present invention is a transceiver unit attached to a ship, configured to transmit ultrasonic waves underwater over a predetermined range and at least configured to be able to receive reflected waves of the ultrasonic waves reflected from each position in the water for each predetermined direction including at least a plurality of directions set in the azimuth direction and the vertical direction; a reception signal generation means for generating a reception signal for each of the predetermined directions based on the reflected waves received by the transceiver unit; a detection result image generation means for generating a detection result image showing the detection result in the water projected onto a plane parallel to the horizontal plane based on the reception signal generated by the reception signal generation means at least in the direction set in the azimuth direction; and a display means for displaying the detection result image generated by the detection result image generation means. The detection result image generation means generates the detection result image such that in a region in a part of the azimuth direction in the detection result image, instead of the detection result in the water projected onto a plane parallel to the horizontal plane, the detection result in the vertical direction based on the reception signal generated by the reception signal generation means in the vertical direction is shown.

[0010] A second aspect of the present invention is an ultrasonic sonar device according to the first aspect, wherein the detection result image generation means generates the detection result image such that the distance in the distance direction of the detection result in the water projected onto a plane parallel to the horizontal plane is associated with the distance in the distance direction of the detection result in the vertical direction.

[0011] A third aspect of the present invention is an ultrasonic sonar device according to the first or second aspect, wherein the detection result image generation means generates the detection result image such that in the detection result in the vertical direction, the stronger the intensity of the reception signal, the longer it is displayed in a direction perpendicular to the distance direction.

[0012] A fourth aspect of the present invention is an ultrasonic sonar device according to any one of the first to third aspects, wherein the detection result image generation means generates the detection result image such that the detection result in the vertical direction is shown in a region corresponding to the rear side of the ship in the detection result image.

[0013] A fifth aspect of the present invention is an ultrasonic sonar device according to any one of the first to fourth aspects, comprising storage means for storing the received signals generated by the received signal generation means for each of the predetermined directions in a received signal array indexed by the direction and the distance at which the reflected wave of the ultrasonic wave serving as the basis of the received signal occurred, the detection result image generation means having a conversion table indicating the direction and the distance of the received signal array corresponding to each coordinate of the detection result image, and based on the conversion table, specifying the level of the received signal at each coordinate of the detection result image from the received signal array and then generating the detection result image, the conversion table associating, for each coordinate included in a region showing the detection result in the water projected onto a plane parallel to the horizontal plane in the detection result image, the direction set in the azimuth direction of the received signal array, and for each coordinate included in a region showing the detection result in the vertical direction in the detection result image, associating the vertical direction.

[0014] A sixth aspect of the present invention is an ultrasonic sonar device according to the fifth aspect, in which a virtual direction in which a predetermined value is shown as the level of a virtual received signal is prepared for all distances in the distance direction, the conversion table associating, for each coordinate included in a region showing the detection result in the vertical direction in the detection result image, the vertical direction or a direction between the vertical direction and the virtual direction, and the detection result image generation means, for coordinates in the conversion table in which the direction between the vertical direction and the virtual direction is associated, specifying the level of the received signal at the coordinates by weighted-averaging the level of the received signal in the vertical direction and the predetermined value in the virtual direction based on the respective distances from the vertical direction and the virtual direction.

Advantages of the Invention

[0015] According to the ultrasonic sonar device according to the first aspect of the present invention, ultrasonic waves are transmitted into the water over a predetermined range by a transmitting and receiving unit attached to a ship, and reflected waves of the ultrasonic waves reflected from each position in the water are received for each predetermined direction including at least a plurality of directions set in the azimuth direction and the vertical direction. Based on the reflected waves received by the transmitting and receiving unit, a reception signal is generated by a reception signal generation means for each predetermined direction. Among the reception signals for each predetermined direction generated by the reception signal generation means, a detection result image showing the detection result in the water projected onto a plane parallel to the horizontal plane is generated by a detection result image generation means based on at least the reception signal in the direction set in the azimuth direction, and the detection result image is displayed by a display means. The user can determine the presence or absence of a detection target object, the direction in which the detection target object exists, and the horizontal distance from the detection result image.

[0016] Here, in the detection result image, the detection result image is generated by the detection result image generation means so that in a region in a part of the azimuth direction, instead of the detection result in the water projected onto a plane parallel to the horizontal plane, the detection result in the vertical direction based on the reception signal generated by the reception signal generation means in the vertical direction is shown. As a result, based on the detection result in the vertical direction shown in a region in a part of the azimuth direction, the user can intuitively imagine the depth with respect to the detection result in the water projected onto a plane parallel to the horizontal plane shown in the detection result image. Therefore, there is an effect that the depth of the detection target object in horizontal detection can be intuitively grasped.

[0017] According to the ultrasonic sonar device according to the second aspect, in addition to the effect exhibited by the ultrasonic sonar device according to the first aspect, the following effect is exhibited. That is, the detection result image is generated by the detection result image generation means so that the distance in the distance direction of the detection result in the water projected onto a plane parallel to the horizontal plane and the distance in the distance direction of the detection result in the vertical direction are associated with each other. Here, the distance in the distance direction of the detection result in the vertical direction is the depth. Therefore, there is an effect that the depth in the detection result in the water projected onto a plane parallel to the horizontal plane can be more intuitively grasped from the distance in the distance direction of the detection result in the vertical direction.

[0018] According to the ultrasonic sonar device according to the third aspect, in addition to the effects achieved by the ultrasonic sonar device according to the first or second aspect, the following effects are achieved. That is, in the detection result in the vertical direction, the detection result image is generated by the detection result image generation means so that the stronger the intensity of the received signal, the longer the length in the direction perpendicular to the distance direction is displayed. As a result, there is an effect that the depth at which a strong reaction occurred in the vertical direction can be more clearly conveyed to the user.

[0019] According to the ultrasonic sonar device according to the fourth aspect, in addition to the effects achieved by the ultrasonic sonar device according to any one of the first to third aspects, the following effects are achieved. That is, in the detection result image, the detection result image is generated by the detection result image generation means so as to show the detection result in the vertical direction in a region corresponding to the rear side of the ship to which the transmission / reception wave unit is attached. A ship is provided with a screw propeller that imparts a propulsive force for advancing forward, and a large number of bubbles are generated behind the ship due to the high-speed rotation of the screw propeller. Since the ultrasonic wave transmitted from the transmission / reception wave unit is also reflected by these bubbles, in the underwater detection result projected onto a plane parallel to the horizontal plane, invalid results based on the reflected waves from the bubbles are often displayed on the rear side of the ship. By showing the detection result in the vertical direction instead of the underwater detection result projected onto a plane parallel to the horizontal plane in the region corresponding to the rear side of the ship in such a detection result image, there is an effect that the display of invalid detection results in the detection result image can be suppressed. Further, by effectively utilizing the region where such invalid detection results are displayed to display the detection result in the vertical direction, there is an effect that the depth of the detection object in the horizontal detection can be intuitively grasped.

[0020] According to the ultrasonic sonar device according to the fifth aspect, in addition to the effects exhibited by the ultrasonic sonar device according to any one of the first to fourth aspects, the following effects are exhibited. That is, by the storage means, the reception signals generated by the reception signal generation means for each predetermined direction are stored in a reception signal array indexed by that direction and the distance at which the reflected wave of the ultrasonic wave serving as the basis of the reception signal occurred. Further, a conversion table indicating the direction and the distance of the reception signal array corresponding to each coordinate of the detection result image is provided in the detection result image generation means. Then, based on the conversion table, the level of the reception signal at each coordinate of the detection result image is specified from the reception signal array, and the detection result image generation means generates the detection result image. Here, in the conversion table, for each coordinate included in the region indicating the detection result in water projected onto a plane parallel to the horizontal plane in the detection result image, the direction set in the azimuth direction of the reception signal array is associated, and for each coordinate included in the region indicating the vertical detection result in the detection result image, the vertical direction is associated. Thereby, if the detection result image generation means generates the detection result image based on the conversion table, it can easily generate a detection result image including a region indicating the detection result in water projected onto a plane parallel to the horizontal plane and a region indicating the vertical detection result with only one coordinate conversion process. Therefore, there is an effect that the detection result image can be generated efficiently.

[0021] According to the ultrasonic sonar device according to the sixth aspect, in addition to the effects achieved by the ultrasonic sonar device according to the fifth aspect, the following effects are achieved. That is, a virtual direction in which a predetermined value is shown as the level of a virtual reception signal is prepared for all distances in the distance direction. In the conversion table, for each coordinate included in the region showing the detection result in the vertical direction among the detection result images, a direction in the vertical direction or a direction between the vertical direction and the virtual direction is associated. Then, by the detection result image generation means, for the coordinates associated with the direction between the vertical direction and the virtual direction in the conversion table, the level of the reception signal in the vertical direction and the predetermined value in the virtual direction are weighted-averaged based on the respective distances from the vertical direction and the virtual direction, thereby specifying the level of the reception signal at the coordinate. As a result, the detection result image generation means can, simply by specifying the level of the reception signal according to the conversion table, display the detection result with a long length in the direction perpendicular to the distance direction where the intensity of the reception signal is strong in the vertical direction. Therefore, there is an effect that, while improving the processing efficiency, the depth at which a strong reaction occurred in the vertical direction can be more clearly conveyed to the user.

Brief Description of the Drawings

[0022]

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Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. Note that each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement positions of the components, connection forms, etc. 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, the components not described in the independent claims indicating the most general concept of the present invention are described as optional components. Also, in each figure, substantially the same configuration is denoted by the same reference numeral, and overlapping explanations are omitted or simplified.

[0024] (First Embodiment) First, with reference to FIGS. 1 to 7, an ultrasonic sonar device 1 according to a first embodiment, which is an embodiment of the present invention, will be described. FIG. 1 is a schematic diagram schematically showing the configuration of the ultrasonic sonar device 1, and FIG. 2 is a schematic diagram showing the state when the underwater detection is performed by a ship 71 on which the ultrasonic sonar device 1 is mounted, as viewed from the side.

[0025] As shown in FIGS. 1 and 2, the ultrasonic sonar device 1 is mounted on a ship 71 and has at least a sonar function for horizontally detecting a detection target object GF such as a fish school over a predetermined range around the ship 71 with respect to water such as the sea, lake, or river in which the ship 71 floats. The horizontal detection is to set the entire azimuth direction as a predetermined range with respect to the azimuth direction as viewed from the ship 71, and to detect the detection target object GF included in the predetermined range.

[0026] In the present embodiment, a case where the predetermined range in which the horizontal detection is performed is the entire azimuth direction as viewed from the ship 71 will be described, but it is not necessarily the entire azimuth, and it may be a part of the azimuth direction as viewed from the ship 71. Further, the ultrasonic sonar device 1 may have a sonar function for performing vertical cross-section detection in addition to the horizontal detection, or may have a fish school detection function for detecting a detection target object GF existing in the vertical direction directly below the ship 71 and arranging the detection results in time series for display.

[0027] The ultrasonic sonar device 1 includes a main body 5, an operation button 31 provided on the main body 5, a display device 21 as a display means integrally formed with the main body 5, a transmitting and receiving unit 50 for transmitting and receiving ultrasonic waves TB for detecting a detection target object GF, and a lifting device 41 for lifting the transmitting and receiving unit 50. The main body 5, the operation button 31, and the display device 21 are arranged in the steering room of the ship 71, and the transmitting and receiving unit 50 and the lifting device 41 are arranged inside the bottom of the ship 71. The transmitting and receiving unit 50 can move in and out of the water from the bottom of the ship 71 by being lifted and lowered by the lifting device 41. Note that the ultrasonic sonar device 1 does not necessarily have to have the lifting device 41, and the transmitting and receiving unit 50 may be fixed to the ship 71 at a position where ultrasonic waves TB can be transmitted and received toward the water.

[0028] The operation button 31 is a button that can be operated by the user and is operated when the user gives various instructions and settings to the ultrasonic sonar device 1. For example, turning on / off the power of the ultrasonic sonar device 1, setting the detection mode (horizontal detection, vertical cross-section detection, fish school detection, etc.) and detection range in the ultrasonic sonar device 1, setting the type and brightness of the image displayed on the display device 21, etc. are performed by the user through the operation of the operation button 31.

[0029] As shown in FIG. 2, the ultrasonic sonar device 1 transmits (irradiates) ultrasonic waves TB in a conical shape as a predetermined range from the transmitting and receiving unit 50 with the transmitting and receiving unit 50 protruding from the bottom of the ship 71. Then, the reflected waves of the ultrasonic waves TB reflected from the detection target object GF included in the conical predetermined range, the seabed or the lake bottom (hereinafter, these are collectively referred to as "water bottom SB"), etc. can be received by the transmitting and receiving unit 50. The detailed configuration of the transmitting and receiving unit 50 will be described later with reference to FIGS. 3 and 4.

[0030] The display device 21, together with the display control means 18 described later, constitutes the display means of the present invention. The display device 21 displays the detection result based on the reception signals generated by the reception units 13a to 13g and the filter 14 (see FIG. 5) described later when the transmission / reception unit 50 receives the reflected wave of the ultrasonic wave TB, and is constituted by, for example, a liquid crystal display or an organic EL (Electro-Luminescence) display. When the ultrasonic sonar device 1 executes horizontal detection by the search function, a horizontal detection result image 22 (see FIG. 5) is displayed on the display device 21 as a detection result image. Details of the horizontal detection result image 22 will be described later with reference to FIG. 5.

[0031] Next, with reference to FIGS. 3 and 4, the detailed configuration of the transmission / reception unit 50 will be described. FIG. 3(a) is a schematic cross-sectional view showing the transmission / reception unit 50, and FIG. 3(b) is a schematic perspective view showing the arrangement modes of a plurality of first vibrators 52 (52a to 52f) and the second vibrator 53 constituting the transmission / reception unit 50.

[0032] Further, FIG. 4(a) is a diagram schematically showing the respective first central axes C1a to C1f of the first vibrators 52a to 52f when viewed vertically from above the ship 71, and FIG. 4(b) is a diagram schematically showing the respective first central axes C1a to C1f of the first vibrators 52a to 52f when viewed horizontally from the front side of the ship 71. Further, FIG. 4(c) is a diagram schematically showing the directivity characteristics of the ultrasonic waves TB transmitted from the adjacent first vibrators 52a, 52b, and 52f, and FIG. 4(d) is a diagram showing the directivity characteristics of the ultrasonic waves TB transmitted from the first vibrator 52a and the first vibrator 52d, respectively, when viewed from the front side of the ship 71.

[0033] As shown in FIG. 3, the transmitting and receiving unit 50 has a structure in which a plurality (six in the example shown in FIG. 3) of first vibrators 52 (first vibrator 52a, first vibrator 52b, first vibrator 52c, first vibrator 52d, first vibrator 52e, first vibrator 52f) that transmit ultrasonic wave TB in a predetermined direction and receive the reflected wave thereof, and a second vibrator 53 are molded in a case 51. Each of the individual first vibrators 52 is a disk-shaped structure having the same size and shape as each other. Also, the second vibrator 53 has a shape on a disk similar to that of the first vibrator 52. However, the size of the second vibrator 53 is determined according to the required characteristics. That is, the second vibrator 53 may be of the same size as the first vibrator 52, or may be of a different size from the first vibrator 52.

[0034] Each of the first vibrator 52 and the second vibrator 53 includes a base material 54 and a piezoelectric element 55. The base material 54 is a disk-shaped resin plate material that also serves as an acoustic matching layer. For example, a base material made of glass epoxy is used.

[0035] The piezoelectric element 55 is a plate-shaped object made of piezoelectric ceramics. For example, a disk-shaped plate made of lead zirconate titanate (PZT) is used. The piezoelectric element 55 has a front-side electrode (not shown) formed on the front surface that is entirely joined to the base material 54 via an adhesive layer (not shown), and a back-side electrode (not shown) formed on the back surface facing the front surface. Lead wires are electrically connected to the front-side electrode and the back-side electrode, respectively.

[0036] When a driving voltage is applied to the piezoelectric element 55 by the front-side electrode and the back-side electrode from the transmitting unit 11a or the transmitting unit 11b (see FIG. 5) described later, the piezoelectric element 55 deforms in the thickness direction to vibrate the base material 54. Due to the vibration of this base material 54, each of the first vibrator 52 and the second vibrator 53 generates ultrasonic wave TB.

[0037] Further, when the base material 54 vibrates due to the reflected wave of the ultrasonic wave TB, each of the first vibrator 52 and the second vibrator 53 causes the piezoelectric element 55 to deform due to the vibration, and a voltage is generated between the front-side electrode and the back-side electrode. The first vibrators 52a to 52f and the second vibrator 53 output the voltage generated between the front-side electrode and the back-side electrode to the corresponding reception units 13a to 13g described later, thereby generating reception signals corresponding to the reflected waves received by the respective first vibrators 52a to 52f and the second vibrator 53.

[0038] The case 51 has an opening at one end, and a plurality of first vibrators 52 and second vibrators 53 are housed in the case 51. The second vibrator 53 is disposed at the center of the case 51. Further, six first vibrators 52 are arranged around the second vibrator 53 in the order of the first vibrator 52a, the first vibrator 52b, the first vibrator 52c, the first vibrator 52d, the first vibrator 52e, and the first vibrator 52f, counterclockwise when viewed from the front side of the base material 54. The acoustic radiation surfaces formed on the front surfaces of the base materials 54 of the respective first vibrators 52 and the acoustic radiation surface formed on the front surface of the base material 54 of the second vibrator 53 are all located on one virtual spherical surface.

[0039] In the present embodiment, six first vibrators 52 are provided. However, the number of the first vibrators 52 may be any number of three or more, preferably four or more, and more preferably six or more. However, when the number of the first vibrators 52 increases, the configuration of the ultrasonic sonar device 1 becomes complicated and the size increases, and it also becomes expensive. Therefore, the number of the first vibrators 52 is preferably ten or less, and more preferably eight or less.

[0040] Here, it can be understood that the direction of the first central axis C1a, which is the central axis orthogonal to the front surface (acoustic radiation surface) of the base material 54, of the first vibrator 52a (which can also be said to be the direction of the normal vector of the first vibrator 52a) is the acoustic radiation direction. Similarly to the first vibrator 52a, a first central axis C1b is defined for the first vibrator 52b, a first central axis C1c is defined for the first vibrator 52c, a first central axis C1d is defined for the first vibrator 52d, a first central axis C1e is defined for the first vibrator 52e, and a first central axis C1f is defined for the first vibrator 52f. And it can be understood that each of the first central axes C1b to C1f is the acoustic radiation direction of the corresponding first vibrators 52b to 52f.

[0041] Also, for the second vibrator 53, it can be understood that the direction of the second central axis C2, which is the central axis orthogonal to the front surface (acoustic radiation surface) of the base material 54, (which can also be said to be the direction of the normal vector of the second vibrator 53) is the acoustic radiation direction.

[0042] That is, the first central axes C1a to C1f of each of the first vibrators 52a to 52f and the second central axis C2 of the second vibrator 53 are directions for transmitting the ultrasonic wave TB to a predetermined range, which is the detection range of the detection target GF, and receiving the reflected wave thereof.

[0043] Here, the transmission / reception wave unit 50 is attached to the ship 71 such that the direction of the second central axis C2 of the second vibrator 53 is in the vertical direction. That is, the second vibrator 53 transmits (irradiates) the ultrasonic wave TB in the vertical direction directly below the ship 71. Due to the presence of this second vibrator 53, the ultrasonic sonar device 1 can detect the detection target GF in the vertical direction with high accuracy. Note that the directivity characteristic of the ultrasonic wave TB transmitted from the second vibrator 53 preferably has a small directivity angle and a narrow beam shape. Thereby, the accuracy of detecting the detection target GF in the vertical direction can be further increased.

[0044] On the other hand, as shown in FIG. 3, in the transmitting and receiving wave unit 50, the acoustic radiation surfaces of the respective first vibrators 52a to 52f are inclined so that the first central axes C1a to C1f form a predetermined angle ω with respect to the second central axis C2 (that is, the vertical direction in the situation where the transmitting and receiving wave unit 50 is attached to the ship 71), and the first vibrators 52a to 52f are respectively arranged. As a result, as shown in FIG. 4(b), the acoustic radiation directions of the respective first vibrators 52a to 52f are different from the vertical direction directly below the ship 71.

[0045] In the present embodiment, the respective first vibrators 52a to 52f are inclined and arranged with their acoustic radiation surfaces facing inward (toward the side where the second vibrator 53 is located) (see FIG. 3). At this time, the first central axes C1a to C1f are preferably set to one angle selected from the range of 20° or more and 50° or less as a predetermined angle ω with respect to the second central axis C2. In the present embodiment, the predetermined angle ω is 30°. As shown in FIG. 3(a), the respective first central axes C1a to C1f and the second central axis C2 are in a state of converging at one point.

[0046] Further, when the transmitting and receiving wave unit 50 is attached to the ship 71 and viewed vertically from above the ship 71, the respective first central axes C1a to C1f of the first vibrators 52a to 52f are arranged at equal intervals in the azimuth direction so that the angle formed by adjacent first central axes C1a to C1f is the same angle δ, as shown in FIG. 4(a). When the number of the first vibrators 52 is n, the angle δ is (360 / n)° (when the number of the first vibrators 52 is 6, the angle δ is 60°).

[0047] As a result, the transmitting and receiving wave unit 50 can simultaneously transmit ultrasonic waves TB in each predetermined direction indicated by the first central axes C1a to C1f by at least the first vibrators 52a to 52f over a predetermined range set in all directions of the ship 71, and can receive reflected waves in each predetermined direction.

[0048] In addition, in the present embodiment, as shown in FIGS. 4(a) and (b), when the ship 71 is viewed vertically from above, the first central axis C1a is directed to the right with respect to the longitudinal direction of the ship 71, and the first central axes C1b to C1f are arranged at intervals of an angle δ counterclockwise in order from the first central axis C1a. The transmitting and receiving wave unit 50 is attached to the ship 71. Further, in the present embodiment, an example is shown in which the first oscillators 52a to 52f are arranged so that the first central axes C1a to C1f of the respective first oscillators 52a to 52f are equally spaced in the azimuth direction. However, as long as the ultrasonic wave TB can be transmitted all at once in each predetermined direction indicated by the first central axes C1a to C1f by at least the first oscillators 52a to 52f over a predetermined range set in all directions of the ship 71, there may be variations in the intervals between the first central axes C1a to C1f. The directions of the first central axes C1a to C1f set as described above correspond to the "plurality of directions set in the azimuth direction" of the present invention.

[0049] The directivity characteristics of the ultrasonic wave TB transmitted from each of the first oscillators 52a to 52f are set to include the first central axes C1a to C1f of the adjacent first oscillators 52. For example, as shown in FIG. 4(c), the directivity characteristics of the ultrasonic wave TB transmitted from the first oscillator 52a are set to include the first central axis C1b of the adjacent first oscillator 52b and the first central axis C1f of the first oscillator 52f.

[0050] On the other hand, the directivity characteristics of the ultrasonic wave TB transmitted from the first oscillator 52b and the directivity characteristics of the ultrasonic wave TB transmitted from the first oscillator 52f are also set to include the first central axis C1a of the first oscillator 52a. Although not shown, the directivity characteristics of the ultrasonic wave TB transmitted from the first oscillator 52b are also set to include the first central axis C1c of the first oscillator 52c adjacent to the opposite side of the first oscillator 52a, and the directivity characteristics of the ultrasonic wave TB transmitted from the first oscillator 52f are also set to include the first central axis C1e of the first oscillator 52e adjacent to the opposite side of the first oscillator 52a.

[0051] Furthermore, as shown in Fig. 4(d), the directivity characteristics of the ultrasonic waves TB transmitted from each of the first oscillators 52a to 52f are set to include the vertical direction in the situation where the transmission / reception unit 50 is attached to the ship 71.

[0052] As described above, the ultrasonic waves TB transmitted from each of the first oscillators 52a to 52f include the first central axes C1a to C1f of the adjacent first oscillators 52, and the directivity characteristics are set to include the vertical direction in the situation where the transmission / reception unit 50 is attached to the ship 71. Thereby, the transmission / reception unit 50 drives each of the first oscillators 52a to 52f simultaneously, so that the ultrasonic waves TB are irradiated from each of the first oscillators 52a to 52f in the directions of the respective first central axes C1a to C1f, and due to the directivity characteristics of the ultrasonic waves TB, the ultrasonic waves TB can be transmitted simultaneously to a predetermined range set in all directions of the ship 71 by a small number of first oscillators 52.

[0053] Also, so that the ultrasonic waves TB are irradiated over a predetermined range from the transmission / reception unit 50, the directions of the first central axes C1a to C1f and the directivity characteristics of the ultrasonic waves TB irradiated from each of the first oscillators 52a to 52f are fixed. Therefore, it is possible to eliminate the circuits for controlling the directions of the first central axes C1a to C1f in the first oscillators 52a to 52f and the circuits for controlling the directivity characteristics of the ultrasonic waves TB irradiated from each of the first oscillators 52a to 52f.

[0054] Then, the transmission / reception unit 50 can receive the reflected waves of the ultrasonic waves TB reflected from the detection target GF existing in the predetermined range in each of the first central axes C1a to C1f, which are the predetermined directions, by the first oscillators 52a to 52f corresponding to the respective first central axes C1a to C1f. From the above, the ultrasonic sonar device 1 can be constructed for high-speed detection in a small size and at low cost.

[0055] The transmitting / receiving unit 50 is arranged and housed in the case 51 with the first vibrators 52a to 52f and the second vibrator 53 being densely packed together so that the first central axes C1a to C1f and the second central axis C2 are in the above-described directions, and is fixed by a filling agent. As this filling agent, a resin material (such as urethane resin, etc.) having a lower specific acoustic impedance than the base material 54 which is the acoustic matching layer of the first vibrator 52 and the second vibrator 53 and having waterproofness is used. The outer surface of the filling agent is filled so as to be flush with the opening of the case 51, whereby the opening of the case 51 is blocked.

[0056] Next, with reference to FIG. 5, the horizontal detection result image 22 will be described. FIG. 5 is a diagram schematically showing an example of a display screen displayed on the display device 21 when the ultrasonic sonar device 1 performs horizontal detection as a sonar function.

[0057] As shown in FIG. 5, when the ultrasonic sonar device 1 performs horizontal detection as a sonar device, the horizontal detection result image 22 is mainly displayed on the display device 21. In addition, when the ultrasonic sonar device 1 performs horizontal detection, in addition to the horizontal detection result image 22, one or more detection result images in which the detection results in the distance direction from the transmitting / receiving unit 50 based on the reception signals in at least one direction are arranged in time series may be displayed on the display device 21 (in the example of FIG. 5, each of the two detection result images displayed vertically in the left region of the display device 21 corresponds). Further, the detection result images other than the horizontal detection result image 22 may be displayed or not displayed on the display device 21 by the user operating the operation button 31. Since the detection result images other than the horizontal detection result image 22 are not necessarily required configurations of the present invention, the description thereof is omitted here.

[0058] The horizontal detection result image 22 is a circular (or sector-shaped) detection result image obtained by projecting the latest underwater detection results 22a in each azimuth direction onto a plane parallel to the horizontal plane for the horizontal detection performed from the ship 71 in all azimuths (or some azimuths). Specifically, based on the received signals in the respective directions of the first central axes C1a to C1f of the first vibrators 52a to 52f, the latest underwater detection results 22a (hereinafter also referred to as "underwater detection results 22a projected onto a plane parallel to the horizontal plane") over a predetermined range set in all azimuths of the ship 71 are displayed on the display device 21 as the horizontal detection result image 22 shown by projecting onto a plane parallel to the horizontal plane.

[0059] The user of the ultrasonic sonar device 1 can easily determine, from the underwater detection results 22a projected onto a plane parallel to the horizontal plane in the horizontal detection result image 22 displayed on the display device 21, in which direction the detection target object GF is currently located with respect to the ship 71, and at what position (how far) it is located in the horizontal direction from the ship 71 (what is the horizontal distance), etc.

[0060] Also, the horizontal detection result image 22 shows the vertical detection results 22b from the ship 71 in a region in some azimuth directions (in the example shown in FIG. 5, the region corresponding to the rear side of the ship 71) instead of the underwater detection results 22a projected onto a plane parallel to the horizontal plane. Specifically, based on the received signal in the direction of the second central axis C2 of the second vibrator 53, the vertical detection results 22b of the ship 71 are shown in a region in some azimuth directions of the horizontal detection result image 22.

[0061] Thereby, based on the vertical detection results 22b shown in a region in some azimuth directions with respect to the underwater detection results 22a projected onto a plane parallel to the horizontal plane shown in the horizontal detection result image 22, the user can intuitively visualize the depth. Therefore, the depth of the detection target object GF in the horizontal detection can be intuitively grasped.

[0062] Here, the horizontal detection result image 22 is generated such that the distance in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane (the radiation direction of the ultrasonic wave TB from the first vibrator 52, i.e., the direction along the first central axes C1a to C1f) is associated with the distance in the distance direction of the vertical detection result 22b (the radiation direction of the ultrasonic wave TB from the second vibrator 53, i.e., the direction along the second central axis C2). The underwater detection result 22a projected onto a plane parallel to the horizontal plane mainly reflects the detection result at a deeper depth as it moves away from the ship 71 in the distance direction (away from the center of the circle in the horizontal detection result image 22). On the other hand, the distance in the distance direction of the vertical detection result 22b is the depth itself. The horizontal detection result image 22 displays the respective detection results 22a and 22b such that the depth of the detection result mainly represented at each position in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane matches the depth of the detection result represented at each position in the distance direction of the vertical detection result 22b. Thereby, from the depth which is the distance in the distance direction of the vertical detection result 22b, the user can more accurately grasp the depth of each position in the underwater detection result 22a projected onto a plane parallel to the horizontal plane.

[0063] Note that the horizontal detection result image 22 may display the respective detection results 22a and 22b such that the slant distance (the distance along the radiation direction of the ultrasonic wave TB from the first vibrator 52, i.e., the distance along the first central axes C1a to C1f) at each position in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane matches the distance (depth) in the distance direction of the vertical detection result 22b.

[0064] In this case, although the depth of the detection result mainly represented at each position in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the depth of the detection result represented at each position in the distance direction of the detection result 22b in the vertical direction do not exactly match, it is possible to intuitively make the user imagine the depth of each position in the underwater detection result 22a projected onto a plane parallel to the horizontal plane. Then, by associating the respective received signals in which the time from transmitting the ultrasonic wave TB from the first vibrator 52 until receiving its reflected wave by the first vibrator 52 and the time from transmitting the ultrasonic wave TB from the second vibrator 53 until receiving its reflected wave by the second vibrator 53 match, and generating the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the detection result 22b in the vertical direction, it is possible to easily obtain a horizontal detection result image 22 in which the slant distance at each position in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the distance (depth) in the distance direction of the detection result 22b in the vertical direction match.

[0065] The horizontal detection result image 22 may be generated such that in the detection result 22b in the vertical direction, the stronger the level (intensity) of the received signal of the reflected wave received from each depth, the longer it is displayed in the azimuth direction, which is the direction perpendicular to the distance direction, at the position corresponding to that depth. Thereby, the depth at which a strong reaction occurred in the vertical direction can be conveyed to the user more clearly. Also, a strong reaction is brought about by a large fish or a school of fish formed by many fish. By generating the horizontal detection result image 22 such that in the detection result 22b in the vertical direction, the stronger the level (intensity) of the received signal of the reflected wave received from each depth, the longer it is displayed in the azimuth direction, which is the direction perpendicular to the distance direction, it becomes easier for the user to imagine that there is a large fish or a school of fish formed by many fish at that position.

[0066] In addition, as shown in FIG. 5, the horizontal detection result image 22 may be generated to show the vertical detection result 22b in a region corresponding to the rear side of the ship 71 to which the transmission / reception wave unit 50 is attached. The ship 71 is provided with a screw propeller (not shown) for applying a propulsive force for advancing forward, and a large number of bubbles are generated behind the ship 71 due to the high-speed rotation of the screw propeller. Since the ultrasonic wave TB transmitted from the transmission / reception wave unit 50 is also reflected by these bubbles, in the underwater detection result 22a projected onto a plane parallel to the horizontal plane, invalid results based on the reflected waves from the bubbles are often displayed on the rear side of the ship 71.

[0067] By showing the vertical detection result 22b instead of the underwater detection result 22a projected onto a plane parallel to the horizontal plane in the region corresponding to the rear side of the ship 71 in such a horizontal detection result image 22, it is possible to suppress the display of invalid detection results on the horizontal detection result image 22. Further, by effectively utilizing the region where such invalid detection results are displayed to display the vertical detection result 22b, the depth of the detection object GF in the horizontal detection can be intuitively grasped.

[0068] Next, with reference to FIG. 6, the electrical configuration of the ultrasonic sonar device 1 will be described. FIG. 6 is a block diagram showing the electrical configuration of the ultrasonic sonar device 1. Inside the main body 5 of the ultrasonic sonar device 1, there is a control device 10, and the control device 10 is provided with transmission units 11a, 11b, diodes 12a to 12g, reception units 13a to 13g, a filter 14, a storage means 15, a detection result image generation means 16, and a display control means 18.

[0069] Each of the transmission units 11a, 11b, the reception units 13a to 13g, the filter 14, the detection result image generation means 16, and the display control means 18 may be configured by hardware, may be realized by software, or may be realized by the cooperation of hardware and software.

[0070] Although not shown in the drawings, the control device 10 includes a CPU (Central Processing Unit) which is an arithmetic unit, a flash memory which is a rewritable non-volatile memory for storing programs executed by the CPU and fixed values referred to by those programs, and / or a ROM (Read Only Memory) which is a non-rewritable non-volatile memory, and a RAM (Random Access Memory) which is a readable and writable volatile memory for temporarily storing various data when the CPU executes a program. These are connected via bus lines.

[0071] Among the transmission units 11a and 11b, the reception units 13a to 13g, the filter 14, the detection result image generation means 16, and the display control means 18, the parts realized by software or by the cooperation of hardware and software are realized by the CPU executing a program. Also, the storage means 15 is constructed in the RAM.

[0072] The transmission unit 11a generates one drive signal for causing the ultrasonic wave TB to be transmitted from the first oscillators 52a to 52f based on an instruction from the CPU. The output of the one drive signal generated by the transmission unit 11a is branched between the transmission unit 11a and the diodes 12a to 12f and distributed to each of the first oscillators 52a to 52f. That is, one after branching is input to the first oscillator 52a via the diode 12a, one is input to the first oscillator 52b via the diode 12b, one is input to the first oscillator 52c via the diode 12c, one is input to the first oscillator 52d via the diode 12d, one is input to the first oscillator 52e via the diode 12e, and one is input to the first oscillator 52f via the diode 12f.

[0073] Diodes 12a to 12f allow the drive signals generated by transmission unit 11a to pass through and be input to corresponding first vibrators 52a to 52f, and block the signals (voltages) generated by receiving reflected waves at each of the first vibrators 52a to 52f from being transmitted to the transmission unit 11a or the branch points of the drive signals output from the transmission unit 11a to the respective first vibrators 52a to 52f.

[0074] One drive signal generated by transmission unit 11a is branched and input to first vibrators 52a to 52f via diodes 12a to 12f. Therefore, each of the first vibrators 52a to 52f having the same shape and the same size can be driven simultaneously and output ultrasonic waves TB of the same intensity at the same timing. Thus, ultrasonic waves TB can be uniformly transmitted in a predetermined direction (i.e., the directions of the first central axes C1a to C1f) included in a predetermined range set in all directions with respect to the ship 71, so that the detection sensitivity can be made uniform in all predetermined directions.

[0075] In addition, since one transmission unit 11a is provided for a plurality of first vibrators 52a to 52f, significant cost reduction and miniaturization can be achieved compared to the case where each of the first vibrators 52a to 52f has an individual transmission unit 11a.

[0076] Also, between the transmission unit 11a and each of the first vibrators 52a to 52f, on the subsequent stage side of the branch point where the drive signal output from the transmission unit 11a branches toward each of the first vibrators 52a to 52f, diodes 12a to 12f are respectively provided. Therefore, it is possible to suppress the signals (voltages) output when each of the first vibrators 52a to 52f receives the reflected wave of the ultrasonic wave TB from flowing back to the transmission unit 11a or entering the signal lines of the other first vibrators 52a to 52f through the branch point and causing interference. Thus, even if one transmission unit 11a is provided for a plurality (six) of first vibrators 52a to 52f, the independence of the signals (voltages) output from each of the first vibrators 52a to 52f can be ensured.

[0077] The transmission unit 11b generates a drive signal for transmitting the ultrasonic wave TB from the second vibrator 53 based on an instruction from the CPU. The output of the drive signal generated by the transmission unit 11b is input to the second vibrator 53 via the diode 12g. The diode 12g allows the drive signal generated by the transmission unit 11b to pass through and be input to the second vibrator 53, and blocks the signal (voltage) generated by receiving the reflected wave in the second vibrator 53 from being transmitted to the transmission unit 11b. By this diode 12g, it is possible to suppress the signal (voltage) output when the second vibrator 53 receives the reflected wave of the ultrasonic wave TB from flowing back to the transmission unit 11b.

[0078] The ultrasonic sonar device 1 is provided with a transmission unit 11b that generates a drive signal for the second vibrator 53 that transmits the ultrasonic wave TB in the vertical direction directly below the ship 71, independently of the transmission unit 11a that generates the drive signals for the first vibrators 52a to 52f. Thereby, the ultrasonic sonar device 1 can function as a normal fish finder by turning off the transmission of the ultrasonic wave TB from the first vibrators 52a to 52f and transmitting only the ultrasonic wave TB from the second vibrator 53, or can control the transmission of the ultrasonic wave TB from the second vibrator 53 independently of the transmission of the ultrasonic wave TB from the first vibrators 52a to 52f when performing horizontal detection as a sonar function.

[0079] In this embodiment, the transmission unit 11a corresponding to the first vibrators 52a to 52f and the transmission unit 11b corresponding to the second vibrator 53 are provided separately. However, if the specification of the ultrasonic sonar device 1 is such that the transmission of the ultrasonic wave TB from the second vibrator 53 can always be performed at the same timing as the first vibrators 52a to 52f, only one transmission unit 11a may be provided for the first vibrators 52a to 52f and the second vibrator 53, and one drive signal may be generated from this transmission unit 11a. Thereby, the ultrasonic sonar device 1 can achieve further significant cost reduction and miniaturization.

[0080] The receiving units 13a to 13g are provided for each of a plurality (six) of first oscillators 52a to 52f and a second oscillator 53. The receiving units 13a to 13g capture, at every lapse of a predetermined time after the corresponding first oscillators 52a to 52f and the second oscillator 53 transmit the ultrasonic wave TB, signals (voltages) output according to the intensity of the reflected wave of the ultrasonic wave TB received by the first oscillators 52a to 52f and the second oscillator 53, and perform sampling for subjecting the captured signals to predetermined processing.

[0081] That is, the receiving unit 13a is connected to the first oscillator 52a, captures a signal (voltage) output according to the intensity of the reflected wave received by the first oscillator 52a, and subjects it to predetermined processing. Further, the receiving unit 13b is connected to the first oscillator 52b, the receiving unit 13c is connected to the first oscillator 52c, the receiving unit 13d is connected to the first oscillator 52d, the receiving unit 13e is connected to the first oscillator 52e, the receiving unit 13f is connected to the first oscillator 52f, and the receiving unit 13g is connected to the second oscillator 53. Each of the receiving units 13b to 13g also captures a signal (voltage) output according to the intensity of the reflected wave received by the connected first oscillators 52b to 52f or the second oscillator 53, and subjects it to predetermined processing.

[0082] The receiving units 13a to 13g each have an amplifier circuit and an analog-digital conversion circuit. Each of the receiving units 13a to 13g samples, at every lapse of a predetermined time after the ultrasonic wave TB is transmitted in the corresponding first oscillators 52a to 52f or the second oscillator 53, a signal (voltage) output from the corresponding first oscillators 52a to 52f or the second oscillator 53. Specifically, the receiving units 13a to 13g, at every lapse of a predetermined time, as predetermined processing, amplify a signal (voltage) captured from the corresponding first oscillators 52a to 52f or the second oscillator 53 by the amplifier circuit, and then convert it into a digital signal (digital value) by an analog-digital conversion circuit (AD conversion circuit).

[0083] Then, the receiving unit 13a outputs, as the received signal received by the first vibrator 52a (the received signal of the reflected wave of the ultrasonic wave TB), the digital signal obtained by the AD conversion circuit to the filter 14. Similarly, the receiving unit 13b outputs, as the received signal of the first vibrator 52b, the receiving unit 13c outputs, as the received signal of the first vibrator 52c, the receiving unit 13d outputs, as the received signal of the first vibrator 52d, the receiving unit 13e outputs, as the received signal of the first vibrator 52e, the receiving unit 13f outputs, as the received signal of the first vibrator 52f, and the receiving unit 13g outputs, as the received signal of the second vibrator 53, the digital signals obtained by the respective AD conversion circuits to the filter 14.

[0084] As described above, one transmission unit 11a is prepared for a plurality (six) of the first vibrators 52a to 52f to achieve cost reduction and miniaturization. On the other hand, the receiving units 13a to 13f are provided for each of the plurality of first vibrators 52a to 52f, so that while maintaining the independence of the signals (voltages) output from the respective first vibrators 52a to 52f, predetermined processing can be performed on each signal (voltage). On the other hand, since the ultrasonic sonar device 1 is configured with fewer vibrators than a conventional scanning sonar, even if receiving units 13a to 13f are prepared for each of the first vibrators 52a to 52f, the entire receiving unit can be miniaturized and cost reduction can be achieved as compared with a conventional scanning sonar.

[0085] Note that the received signals output from the receiving units 13a to 13g are original received signals indicating the values of the intensities of the reflected waves of the ultrasonic wave TB received by the corresponding first vibrators 52a to 52f and the second vibrator 53 as they are. This original received signal means the received signal before the filter processing by the filter 14 described below is performed.

[0086] The filter 14 performs predetermined filter processing on the received signals (original received signals) output from the receiving units 13a to 13g for each of the first vibrators 52a to 52f and the second vibrator 53. The predetermined filter processing may include spatial filter processing and may also include temporal filter processing.

[0087] As the spatial filtering process, for the purpose of noise reduction and / or resolution improvement, etc., for each original received signal of the first vibrators 52a to 52f that receive the reflected waves of the ultrasonic wave TB for each predetermined azimuth, filtering processing is performed in the azimuth direction and the distance direction. Further, the spatial filtering process includes those that perform filtering processing in the distance direction for the original received signal of the second vibrator 53 that receives the reflected wave of the ultrasonic wave TB from the vertical direction directly below the ship 71.

[0088] Here, the azimuth direction is the direction in which the respective first central axes C1a to C1f of the first vibrators 52a to 52f, that is, the respective acoustic radiation directions, are arranged. In other words, it is the circumferential direction centered on the ship 71. Also, the distance direction is the direction in which the ultrasonic wave TB is transmitted on each of the respective first central axes C1a to C1f of the first vibrators 52a to 52f and the second central axis C2 of the second vibrator 53, that is, the acoustic radiation directions themselves.

[0089] Note that when the ultrasonic sonar device 1 performs horizontal detection by the sonar function, since detection is performed with a small number (six in this embodiment) of vibrators among the first vibrators 52a to 52f, the azimuth resolution is greatly reduced. Therefore, in the filter 14, in horizontal detection, for each of the first central axes C1a to C1f of the first vibrators 52a to 52f, which are the predetermined directions in which the ultrasonic wave TB is transmitted and received, a virtual direction is set at a position intermediate between the adjacent first central axes C1a to C1f, and a received signal assumed to have virtually transmitted and received the ultrasonic wave TB in that virtual direction may be generated from the respective received signals of the first vibrators 52a to 52f.

[0090] By generating a virtual received signal in the virtual direction, the number of directions in which the ultrasonic wave TB is transmitted and received can be made several times (12 directions in this embodiment) the number of actual first vibrators 52 including the virtual direction, and the azimuth resolution can be improved.

[0091] As the spatial filtering process, for the original reception signals of each of the first vibrators 52a to 52f that receive the reflected waves of the ultrasonic wave TB for each predetermined azimuth, for the purpose of noise reduction and / or resolution improvement, etc., filtering processes are executed in the azimuth direction and the distance direction. Further, the spatial filtering process includes those that execute a filtering process in the distance direction for the original reception signal of the second vibrator 53 that receives the reflected wave of the ultrasonic wave TB from the vertical direction directly below the ship 71.

[0092] On the other hand, the temporal filtering process is to execute a filtering process in combination with at least one reception signal received earlier in time and / or at least one reception signal received later in time in the same direction and at the same distance (or depth) with respect to the reception signal indicating the intensity of the reflected wave reflected from one distance (or depth) in one direction. By this temporal filtering process, the horizontal detection result image 22 described later displayed on the display device 21 can be changed smoothly in time, and the user can visually recognize the horizontal detection result image 22 without discomfort.

[0093] When the filter 14 performs a predetermined filtering process on the original reception signals of each of the first vibrators 52a to 52f and the second vibrator 53, the values obtained by the filtering process are used as the reception signals of each of the first vibrators 52a to 52f and the second vibrator 53, and also, when generating a virtual reception signal for a virtual direction, the virtual reception signal is also included and stored in the storage means 15. Note that the reception units 13a to 13g and the filter 14 correspond to the reception signal generation means of the present invention.

[0094] The storage means 15 stores, for each of the first vibrators 52a to 52f and the second vibrator 53 (that is, for each of the directions of the first central axes C1a to C1f and the second central axis C2), the reception signals of each of the first vibrators 52a to 52f and the second vibrator 53 after the filtering process generated by the filter 14 in the reception signal array 15a. When generating a virtual reception signal for a virtual direction, the virtual reception signal is also stored in the reception signal array 15a for each virtual direction.

[0095] Here, referring to FIG. 7, the details of the received signal array 15a will be described. FIG. 7 is a diagram schematically showing the content of the received signal array 15a. Note that FIG. 7 shows the received signal array 15a when the filter 14 does not generate a virtual received signal in the virtual direction in order to simplify the explanation. When the filter 14 generates a virtual received signal in the virtual direction, the virtual received signals in their respective virtual directions are also stored in the received signal array 15a.

[0096] The received signal array 15a is a two-dimensional array with the direction θ (i.e., the direction of each of the first central axes C1a to C1f and the second central axis C2) in which the reflected wave of the ultrasonic wave TB serving as the basis of the received signal is received, and the distance R from the transmission / reception unit 50 at the position where the reflected wave of the ultrasonic wave serving as the basis of the received signal occurred, as indexes. That is, the received signal array 15a stores the intensity (level) of the reflected wave reflected from each position specified in polar coordinates composed of the direction θ and the distance R as the level of the received signal.

[0097] For the direction θ, with respect to each of the first central axes C1a to C1f which are the directions for receiving the reflected wave of the ultrasonic wave TB set in the azimuth direction, "1" to "6" are assigned clockwise from the front direction of the ship 71 when viewed vertically from above the ship 71. That is, in the direction θ, "1" indicates the direction of the first central axis C1b, "2" indicates the direction of the first central axis C1a, "3" indicates the direction of the first central axis C1f, "4" indicates the direction of the first central axis C1e, "5" indicates the direction of the first central axis C1d, and "6" indicates the direction of the first central axis C1c. Also, for the direction θ, "7" is assigned to the second central axis C2 which is the vertical direction. That is, in the direction θ, "7" indicates the direction of the second central axis C2.

[0098] In addition, when a virtual direction is set one by one between every two first central axes C1, and the filter 14 generates a virtual reception signal in each virtual direction, as the direction θ, for example, the first central axis C1b is "1", the virtual direction between the first central axis C1b and the first central axis C1a is "2", the first central axis C1a is "3", the virtual direction between the first central axis C1a and the first central axis C1f is "4", the first central axis C1f is "5", the virtual direction between the first central axis C1f and the first central axis C1e is "6", the first central axis C1e is "7", the virtual direction between the first central axis C1e and the first central axis C1d is "8", the first central axis C1d is "9", the virtual direction between the first central axis C1d and the first central axis C1c is "10", the first central axis C1c is "11", and the virtual direction between the first central axis C1c and the first central axis C1b is "12" may be assigned. And in this case, "13" may be assigned as the direction θ with respect to the second central axis C2 which is the vertical direction.

[0099] On the other hand, numbers from "1" to "100" are assigned to the distance R. Then, in the first oscillators 52a to 52f or the second oscillator 53 corresponding to each direction θ, when sampling is performed by the corresponding reception units 13a to 13g at every elapse of a predetermined time after the ultrasonic wave TB is transmitted and a reception signal is output, numbers from "1" to "100" are assigned to the output reception signal one by one in ascending order. As is known, the elapsed time after the ultrasonic wave TB is transmitted and the distance to the position where the ultrasonic wave TB is reflected are in a proportional relationship. Therefore, the distance R assigned in this way can indicate the distance from the transmission / reception wave unit 50 to the position where the reflection of the ultrasonic wave TB occurred.

[0100] The memory means 15 stores the level RSL(R,θ) of the received signal of the reflected wave reflected from the position specified by the direction θ and the distance R in the element specified by the direction θ and the distance R of the received signal array 15a. For example, after the first vibrator 52b that transmits and receives the ultrasonic wave TB with respect to the direction of the first central axis C1b transmits the ultrasonic wave TB, the level RSL(1,1) of the received signal sampled first (the first one) with respect to the first vibrator 52b is stored in the element of the received signal array 15a indicated by the index where the direction θ is "1" and the distance R is "1". Also, after the second vibrator 53 that transmits and receives the ultrasonic wave TB with respect to the direction of the second central axis C2 (vertical direction) transmits the ultrasonic wave TB, the level RSL(100,7) of the received signal sampled 100th with respect to the second vibrator 53 is stored in the element of the received signal array 15a indicated by the index where the direction θ is "7" and the distance R is "100".

[0101] Returning to FIG. 6, the description will be continued. The detection result image generation means 16 generates a horizontal detection result image 22 to be displayed on the display device 21 when the ultrasonic sonar device 1 performs horizontal detection as a sonar function, using the received signal array 15a stored in the memory means 15. The detection result image generation means 16 includes a horizontal detection result image generation means 16a and a vertical detection result image generation means 16b. The horizontal detection result image generation means 16a generates a detection result 22a in water projected onto a plane parallel to the horizontal plane among the horizontal detection result images 22.

[0102] Here, the detection result image generation means 16 manages the positions of the pixels of the horizontal detection result image 22 in a rectangular coordinate system composed of an X coordinate and a Y coordinate. The horizontal detection result image generation means 16a has a conversion table that associates the coordinates (R, θ) of a polar coordinate system composed of a direction θ and a distance R, which are the indexes of the received signal array 15a corresponding to the coordinates (X, Y) indicating the positions of the pixels of the horizontal detection result image 22. Here, the direction θ associated in the conversion table satisfies 1 ≤ θ < 7. Here, the direction indicated by 6 ≤ θ < 7 means the direction included from the direction θ (the direction of the first central axis C1c) indicated by "6" to the direction θ (the direction of the first central axis C1b) indicated by "1". That is, only the direction θ in the azimuth direction is associated in this conversion table.

[0103] The horizontal detection result image generation means 16a uses the conversion table to specify, for each pixel, the coordinates (R, θ) of the polar coordinate system corresponding to the coordinates (X, Y) of that pixel. Then, the detection result image generation means 16 specifies, for each pixel, the level of the received signal at the position of the coordinates (R, θ) specified for that pixel from the received signal array 15a stored in the storage means 15, and sets the level of the specified received signal as the level of the received signal of that pixel. Thereby, the horizontal detection result image generation means 16a can specify the level of the received signal of each pixel indicating the underwater detection result 22a projected onto a plane parallel to the horizontal plane from the level of the received signal in the azimuth direction stored in the received signal array 15a.

[0104] Here, the direction θ and the distance R, which are the coordinates of the polar coordinate system corresponding to the coordinates (X, Y), are not necessarily natural numbers used as the indexes of the received signal array 15a, and most often are represented by decimals. In this case, the level of the received signal at the position of the coordinates (R, θ) is specified by weighted-averaging the levels of the received signals of the four elements closest to the position of the coordinates (R, θ) represented by decimals among the elements of the received signal array 15a. The weighted average is calculated such that the level of the received signal of the element of the received signal array 15a closer to the position of the coordinates (R, θ) is more greatly reflected among the four elements.

[0105] For example, the level of the received signal at the position of coordinates (R,θ) = (49.8, 2.3) is calculated by weighted-averaging the levels of the received signals of the elements of the received signal array 15a indicated by the respective indices of (R,θ) = (49, 2), (49, 3), (50, 2), and (50, 3).

[0106] Also, the level of the received signal at the position of coordinates (R,θ) = (19.2, 6.7) is calculated by weighted-averaging the levels of the received signals of the elements of the received signal array 15a indicated by the respective indices of (R,θ) = (19, 6), (19, 1), (20, 6), and (20, 1). The index of "1" is used as the direction θ because the direction adjacent to the direction indicated by θ = "6" is the direction indicated by θ = "1" in the clockwise direction.

[0107] On the other hand, the vertical detection result image generation means 16b generates a vertical detection result 22b among the horizontal detection result images 22. The vertical detection result image generation means 16b specifies the level of the received signal at the position of the coordinates (X, Y) indicating the position of each pixel included in the region (for example, the region corresponding to the rear side of the ship 71) where the vertical detection result 22b is to be displayed instead of the underwater detection result 22a projected onto a plane parallel to the horizontal plane among the horizontal detection result images 22, from the elements of the received signal array 15a in which the direction θ is "7".

[0108] At this time, the vertical detection result image generation means 16b generates the vertical detection result 22b so that the distance in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the distance in the distance direction of the vertical detection result 22b in the horizontal detection result image 22 are associated with each other. Thereby, as described above, the depth in the underwater detection result 22a projected onto a plane parallel to the horizontal plane can be more intuitively grasped from the depth, which is the distance in the distance direction of the vertical detection result 22b.

[0109] Further, the vertical detection result image generation means 16b generates a vertical detection result 22b such that, the stronger the level of the received signal of the reflected wave from the distance R (depth), the longer it is displayed in the azimuth direction, which is a direction perpendicular to the distance direction, at the position corresponding to the distance R. Thereby, the depth at which a strong reaction occurred in the vertical direction can be clearly conveyed to the user. Also, it can make it easier for the user to imagine that there is a fish school formed by large fish or many fish at that position.

[0110] The detection result image generation means 16 replaces the level of the received signal of the underwater detection result 22a projected onto a plane parallel to the horizontal plane where the level of the received signal was specified by the horizontal detection result image generation means 16a, with the level of the received signal of the vertical detection result 22b whose level was specified by the vertical detection result image generation means 16b, for the area where the vertical detection result 22b is to be displayed. Then, the detection result image generation means 16 assigns a color corresponding to the level of the received signal of each pixel of the horizontal detection result image 22. Thereby, the detection result image generation means 16 can generate the horizontal detection result image 22.

[0111] The display control means 18 performs control for causing the display device 21 to display the horizontal detection result image 22 generated by the detection result image generation means 16 and other images. For example, the display control means 18 adjusts the size and display position of the horizontal detection result image 22 and other detection result images, and also synthesizes characters, symbols, graphics, etc. with the horizontal detection result image 22 etc. to cause the display device 21 to display one image.

[0112] Next, a method of performing horizontal detection by the sonar function using the ultrasonic sonar device 1 of the present embodiment configured as described above will be mainly described with reference to FIG. 6.

[0113] When the user turns on the power of the ultrasonic sonar device 1 via the operation button 31, or when an instruction to start the execution of horizontal detection by the sonar function is given while the power is on, first, the ultrasonic sonar device 1 drives the lifting device 41 to cause the transmitting and receiving unit 50 to emerge from the bottom of the ship 71 into the water. In the case of the ultrasonic sonar device 1 that does not have the lifting device 41 and in which the transmitting and receiving unit 50 is fixed to the ship 71 at a position where it can transmit and receive the ultrasonic wave TB toward the water, the driving operation of the lifting device 41 is omitted.

[0114] Next, the ultrasonic sonar device 1 outputs drive signals from the transmission unit 11a and the transmission unit 11b, and transmits ultrasonic waves TB from the first vibrators 52a to 52f and the second vibrator 53 of the transmitting and receiving unit 50 in the directions of the first central axes C1a to C1f and the second central axis C2, respectively. Due to the directivity characteristics of the ultrasonic waves TB transmitted from each of the first central axes C1a to C1f, the ultrasonic waves TB are transmitted in all directions with respect to the ship 71.

[0115] The ultrasonic waves TB transmitted from the first vibrators 52a to 52f and the second vibrator 53 are reflected from a detection target GF, the bottom SB, etc. existing in a predetermined range where the ultrasonic waves TB are transmitted. The reflected waves are received by the first vibrators 52a to 52f and the second vibrator 53, and signals (voltages) are output from the first vibrators 52a to 52f and the second vibrator 53 as the intensities of the reflected waves received in the directions of the first central axes C1a to C1f and the second central axis C2, respectively.

[0116] The signals (voltages) output from the first vibrators 52a to 52f and the second vibrator 53 are amplified by the corresponding receiving units 13a to 13g provided for each of them every time a predetermined time elapses after the transmission of the ultrasonic waves TB, and then sampled by being converted into digital signals (digital values), and output as received signals (original received signals) in the directions of the first central axes C1a to C1f and the second central axis C2.

[0117] These original received signals are spatially (and temporally) filtered by filter 14. Also, by filter 14, for each of the first central axes C1a to C1f, a virtual direction is set at a position intermediate to adjacent first central axes C1a to C1f, and a received signal assuming that ultrasonic wave TB is virtually transmitted and received in that virtual direction may be generated from each of the received signals of the first vibrators 52a to 52f.

[0118] The levels of the received signals in the directions of the first central axes C1a to C1f and the second central axis C2 after the filtering process output by filter 14 are stored by the storage means 15 in each element of the received signal array 15a shown in FIG. 7. When the level of the virtual received signal in the virtually set virtual direction is also output, the level of that virtual received signal is also stored in each element of the received signal array 15a.

[0119] Then, based on the levels of the received signals in the directions of the first central axes C1a to C1f (directions set in the azimuth direction) stored in the received signal array 15a, the underwater detection result 22a projected onto a plane parallel to the horizontal plane is generated by the horizontal detection result image generation means 16a. Also, based on the levels of the received signals in the direction of the second central axis C2 (vertical direction) stored in the received signal array 15a, the vertical detection result 22b is generated by the vertical detection result image generation means 16b. Furthermore, by the detection result image generation means 16, the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the vertical detection result 22b instead of the underwater detection result 22a projected onto a plane parallel to the horizontal plane in a partial region of the underwater detection result 22a projected onto a plane parallel to the horizontal plane are shown in the horizontal detection result image 22 (see FIG. 5). Then, this horizontal detection result image 22 is displayed on the display device 21 by the display control means 18.

[0120] As described above, according to the ultrasonic sonar device 1 according to the first embodiment, when performing horizontal detection by the sonar function, ultrasonic waves TB are transmitted into the water over a predetermined range by the transmitting and receiving unit 50 attached to the ship 71, and for each of a plurality of directions (directions of the first central axes C1a to C1f) set in the azimuth direction and the vertical direction (direction of the second central axis C2), reflected waves of the ultrasonic waves TB reflected from each position in the water are received. Based on the reflected waves received by the transmitting and receiving unit 50, received signals are generated by the receiving units 13a to 13g and the filter 14 for each of the directions of the first central axes C1a to C1f and the second central axis C2. Among the received signals for each of the directions of the generated first central axes C1a to C1f and the second central axis C2, based on at least the received signals in the directions of the first central axes C1a to C1f set in the azimuth direction, a horizontal detection result image 22 including the underwater detection result 22a projected onto a plane parallel to the horizontal plane is generated by the detection result image generation means 16, and the horizontal detection result image 22 is displayed by the display means. The user can determine the presence or absence of the detection target object GF, the direction in which the detection target object GF exists, and the horizontal distance from the underwater detection result 22a projected onto a plane parallel to the horizontal plane shown in this horizontal detection result image 22.

[0121] Here, in the horizontal detection result image 22, in a partial azimuth direction region of the underwater detection result 22a projected onto a plane parallel to the horizontal plane, instead of the underwater detection result 22a projected onto a plane parallel to the horizontal plane, a vertical direction detection result 22b based on the received signal generated by the receiving unit 13g and the filter 14 in the vertical direction is shown, and the horizontal detection result image 22 is generated by the detection result image generation means 16. Thereby, with respect to the underwater detection result 22a projected onto a plane parallel to the horizontal plane shown in the horizontal detection result image 22, the user can intuitively visualize the depth based on the vertical direction detection result 22b shown in a partial azimuth direction region. Therefore, the user can intuitively grasp the depth of the detection target object GF in horizontal detection.

[0122] Further, a horizontal detection result image 22 is generated by the detection result image generation means 16 so that the distance in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the distance in the distance direction of the detection result 22b in the vertical direction are associated with each other. Here, the distance in the distance direction of the detection result 22b in the vertical direction is the depth. Therefore, the depth in the underwater detection result 22a projected onto a plane parallel to the horizontal plane can be more intuitively grasped from the distance in the distance direction of the detection result 22b in the vertical direction.

[0123] (Second Embodiment) Subsequently, with reference to FIGS. 8 to 10, the ultrasonic sonar device 1 according to the second embodiment of the present invention will be described. FIG. 8 is a block diagram showing the electrical configuration of the ultrasonic sonar device 1 according to the second embodiment. FIG. 9 is a diagram schematically showing the content of the received signal array 15b stored in the storage means 15 of the ultrasonic sonar device 1 according to the second embodiment. FIG. 10 is a schematic diagram schematically showing the conversion table 16c included in the detection result image generation means 16 of the ultrasonic sonar device 1 according to the second embodiment.

[0124] Here, when the ultrasonic sonar device 1 according to the first embodiment performs horizontal detection by the sonar function, the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the detection result 22b in the vertical direction are generated separately, and then, in a partial azimuth direction region of the underwater detection result 22a projected onto a plane parallel to the horizontal plane and shown, the horizontal detection result image 22 is generated so that the detection result 22b in the vertical direction is shown instead of the underwater detection result 22a projected onto a plane parallel to the horizontal plane. On the other hand, the ultrasonic sonar device 1 according to the second embodiment generates a horizontal detection result image 22 including the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the detection result 22b in the vertical direction by using one conversion table 16c (see FIG. 10) in a single coordinate conversion process.

[0125] Hereinafter, the ultrasonic sonar device 1 according to the second embodiment will be described centering on the points different from the ultrasonic sonar device 1 according to the first embodiment. The same components as those of the ultrasonic sonar device 1 according to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

[0126] The difference between the ultrasonic sonar device 1 according to the second embodiment and the ultrasonic sonar device 1 according to the first embodiment is that the storage means 15 stores the received signal array 15b shown in FIG. 9 instead of the received signal array 15a (see FIG. 7), and the detection result image generation means 16 has a conversion table 16c instead of the horizontal detection result image generation means 16a and the vertical detection result image generation means 16b.

[0127] The received signal array 15b is the same as the received signal array 15a according to the first embodiment in that it stores the received signals of each of the first vibrators 52a to 52f and the second vibrator 53 (i.e., in the directions of the first central axes C1a to C1f and the second central axis C2 respectively) after being filtered by the filter 14 for each of the first vibrators 52a to 52f and the second vibrator 53.

[0128] However, in the received signal array 15b, "1" to "9" are prepared as indexes in the direction θ. Among these, in the direction θ, "1" to "6" store the received signals of the first vibrators 52a to 52f, that is, the received signals in the directions of the first central axes C1a to C1f set in a plurality of azimuth directions, in the same manner as the received signal array 15a. On the other hand, as shown in FIG. 9, the received signal array 15b stores the received signal of the second vibrator 53, that is, the received signal in the direction of the second central axis C2 which is the vertical direction, not in the element where the direction θ is "7", but in the element where the direction θ is "8". In addition, in the received signal array 15b, elements with directions θ of "7" and "9" are prepared as virtual directions, and for these directions θ, a predetermined value CL is stored in advance as the level of virtual received signals in all elements of the distance R ("1" to "100"). As this predetermined value CL, "0", or a value that can be almost ignored as the level of the received signal (for example, a value of "15" or less), or a value of the level of the received signal to which a color almost the same as the background color in the horizontal detection result image 22 is assigned, is set. Note that the predetermined value CL may be configured to be changeable by the user operating the operation button 31.

[0129] Note that the virtual directions indicated by the directions θ of "7" and "9" are different from the virtual directions set with respect to the azimuth direction described in the first embodiment, and their technical meanings are also different. The technical meanings of the virtual directions indicated by the directions θ of "7" and "9" will be clarified in the following description.

[0130] The conversion table 16c provided in the detection result image generation means 16 shown in FIG. 8 associates the coordinates (X, Y) indicating the positions of the respective pixels of the horizontal detection result image 22 with the coordinates (R, θ) in the polar coordinate system composed of the direction θ and the distance R, which are the indexes of the reception signal array 15b, corresponding to the coordinates (X, Y). In this regard, it is the same as the conversion table described in the first embodiment. However, as shown in FIG. 10, the conversion table 16c of the second embodiment is composed of a horizontal detection conversion table section 16c1 (the white cell portion in FIG. 10) and a vertical detection conversion table section 16c2 (the gray cell portion in FIG. 10).

[0131] The horizontal detection conversion table section 16c1 associates the coordinates (X, Y) of each pixel included in the region indicating the underwater detection result 22a projected onto a plane parallel to the horizontal plane in the horizontal detection result image 22 with the coordinates (R, θ) in the polar coordinate system composed of the direction θ and the distance R, which are the indexes of the reception signal array 15b, corresponding to the coordinates (X, Y). Note that there are locations where null data is associated instead of associating the coordinates (R, θ) in the polar coordinate system with the coordinates (X, Y). This means that the coordinates (X, Y) are outside the region of the circular horizontal detection result image 22.

[0132] The direction θ associated in the horizontal detection conversion table section 16c1 satisfies 1 ≤ θ < 7. Here, the direction indicated by 6 ≤ θ < 7 means the direction included from the direction θ (the direction of the first central axis C1c) indicated by "6" to the direction θ (the direction of the first central axis C1b) indicated by "1".

[0133] On the other hand, the vertical detection conversion table unit 16c2 associates the coordinates (X, Y) of each pixel included in the region indicating the vertical detection result 22b in the vertical direction (for example, the region corresponding to the rear side of the ship 71) of the horizontal detection result image 22 with the coordinates (R, θ) in the polar coordinate system consisting of the direction θ and the distance R, which are the indices of the reception signal array 15b, corresponding to the coordinates (X, Y).

[0134] The direction θ associated in the vertical detection conversion table unit 16c2 satisfies 7 ≤ θ ≤ 9. Specifically, for the coordinates (X, Y) of each pixel located at the center of the region indicating the vertical detection result 22b, "8.00" is associated as the direction θ. As a result, for each pixel located at the center of the region indicating the vertical detection result 22b, the level of the reception signal in the vertical direction (the direction of the second central axis C2), which is stored in the element with the direction θ being "8" in the reception signal array 15b, is assigned. Therefore, the level of the reception signal in the vertical direction (the direction of the second central axis C2) is shown for each pixel located at the center of the region indicating the vertical detection result 22b.

[0135] On the other hand, in the vertical detection conversion table unit 16c2, for the coordinates (X, Y) of each pixel at a position away from each pixel located at the center of the region indicating the vertical detection result 22b, a decimal value closer to "7" or "9" as the direction θ is associated as the distance from the central position increases. That is, the vertical detection conversion table unit 16c2 associates the direction between the vertical direction with the direction θ being "8" or a decimal in the range of "7" to "9" excluding "8" with the coordinates (X, Y) of each pixel included in the region indicating the vertical detection result 22b in the horizontal detection result image 22.

[0136] In addition, the vertical detection conversion table section 16c2 associates the coordinates (R, θ) in the polar coordinate system with the coordinates (X, Y) of each pixel such that the distance in the distance direction (the radiation direction of the ultrasonic wave TB from the first vibrator 52, i.e., the direction along the first central axes C1a to C1f) of the underwater detection result 22a projected onto a plane parallel to the horizontal plane in the horizontal detection result image 22 corresponds to the distance in the distance direction (the radiation direction of the ultrasonic wave TB from the second vibrator 53, i.e., the direction along the second central axis C2) of the vertical detection result 22b. Specifically, the vertical detection conversion table section 16c2 is defined such that the depth of the detection result mainly represented at each position in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane matches the depth of the detection result represented at each position in the distance direction of the vertical detection result 22b.

[0137] In the ultrasonic sonar device 1 configured as described above, it operates as follows. That is, the detection result image generation means 16 uses the conversion table 16c to specify the coordinates (R, θ) in the polar coordinate system corresponding to the coordinates (X, Y) of each pixel. Then, for each pixel, the detection result image generation means 16 specifies the level of the received signal at the position of the coordinates (R, θ) specified for that pixel from the received signal array 15b stored in the storage means 15, and sets the level of the specified received signal as the level of the received signal for that pixel.

[0138] Here, the conversion table 16c is composed of a horizontal detection conversion table section 16c1 corresponding to the area showing the underwater detection result 22a projected onto a plane parallel to the horizontal plane in the horizontal detection result image 22, and a vertical detection conversion table section 16c2 corresponding to the area showing the vertical detection result 22b in the horizontal detection result image 22. By using such a single conversion table 16c, the detection result image generation means 16 can generate a horizontal detection result image 22 having the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the vertical detection result 22b in a single image conversion process.

[0139] In addition, in the conversion table 16c, the direction θ and the distance R, which are the coordinates in the polar coordinate system corresponding to the coordinates (X, Y), are represented as decimals. Also in this case of the second embodiment, the detection result image generation means 16 specifies the reception signal level at the position of the coordinates (R, θ) by weighted-averaging the reception signal levels of four elements adjacent to the position of the coordinates (R, θ) represented as decimals. The weighted average is calculated such that the reception signal level of the element of the reception signal array 15a close to the position of the coordinates (R, θ) among the four elements is greatly reflected.

[0140] On the other hand, as described above, in the vertical detection conversion table section 16c2 of the conversion table 16c, for the coordinates (X, Y) of each pixel at a position away from the center of the region indicating the vertical detection result 22b, the closer the distance from the center position, the closer the decimal value of the direction θ is to "7" or "9". Thereby, the detection result image generation means 16 can specify the reception signal level in the region of the vertical detection result 22b according to the vertical detection conversion table section 16c2 as described above, so that the strong reception signal intensity in the vertical direction can be propagated in the azimuth direction, which is perpendicular to the distance direction (vertical direction). Therefore, it is possible to easily inform the user of the depth at which a strong reaction occurred in the vertical direction from the vertical detection result 22b. Also, it is possible to easily make the user imagine the presence of a large fish or a fish school formed by many fish at that position. This is the technical significance of introducing the virtual directions indicated by the direction θ of "7" and "9".

[0141] Also, as described above, the vertical detection conversion table section 16c2 associates the coordinates (R, θ) in the polar coordinate system with the coordinates (X, Y) of each pixel so that the distance in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the distance in the distance direction of the vertical detection result 22b in the horizontal detection result image 22 are associated with each other. As a result, the horizontal detection result image 22 generated by the detection result image generation means 16 has the distance in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the distance in the distance direction of the vertical detection result 22b associated with each other. Therefore, it is possible to intuitively grasp the depth in the underwater detection result 22a projected onto a plane parallel to the horizontal plane from the distance in the distance direction of the vertical detection result 22b, which is the depth.

[0142] In particular, the vertical detection conversion table section 16c2 associates the coordinates (R, θ) in the polar coordinate system with the coordinates (X, Y) of each pixel so that the depth of the detection result mainly represented at each position in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane in the horizontal detection result image 22 and the depth of the detection result represented at each position in the distance direction of the vertical detection result 22b match. Thus, it is possible to more accurately grasp the depth in the underwater detection result 22a projected onto a plane parallel to the horizontal plane from the distance in the distance direction of the vertical detection result 22b, which is the depth.

[0143] Note that the vertical detection conversion table section 16c2 may associate the coordinates (R, θ) in the polar coordinate system with the coordinates (X, Y) of each pixel so that the slant distance at each position in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane in the horizontal detection result image 22 and the distance (depth) in the distance direction of the vertical detection result 22b match. In this case, the depth of the detection result mainly represented at each position in the distance direction of the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the depth of the detection result represented at each position in the distance direction of the vertical detection result 22b do not exactly match, but it is possible to make the user intuitively imagine the depth in the underwater detection result 22a projected onto a plane parallel to the horizontal plane.

[0144] As described above, according to the ultrasonic sonar device 1 according to the second embodiment, in addition to the effects achieved by the ultrasonic sonar device 1 according to the first embodiment, the following effects are achieved.

[0145] That is, by the storage means 15, for each direction of the first central axes C1a to C1f and the second central axis C2, the received signals generated by the reception units 13a to 13g and the filter 14 are stored in the reception signal array 15b using the direction θ and the distance R at which the reflected wave of the ultrasonic wave TB serving as the basis of the received signal occurred as indexes. Further, a conversion table 16c showing the direction θ and the distance R of the reception signal array 15b corresponding to the coordinates (X, Y) of each position of the horizontal detection result image 22 is provided in the detection result image generation means 16. Then, based on the conversion table 16c, the level of the received signal at the coordinates (X, Y) of each position of the horizontal detection result image 22 is specified from the reception signal array 15b, and the horizontal detection result image 22 is generated by the detection result image generation means 16.

[0146] Here, in the conversion table 16c, for each coordinate (X, Y) included in the region showing the underwater detection result 22a projected onto a plane parallel to the horizontal plane among the horizontal detection result images 22, the direction θ (1 ≤ θ < 7) set in the azimuth direction of the reception signal array 15b is associated, and for each coordinate (X, Y) included in the region showing the vertical detection result 22b among the horizontal detection result images 22, the vertical direction (7 ≤ θ ≤ 9) is associated. Thereby, without considering the region showing the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the region showing the vertical detection result 22b, if the detection result image generation means 16 generates the horizontal detection result image 22 based on the conversion table 16c, the horizontal detection result image 22 including the region showing the underwater detection result 22a projected onto a plane parallel to the horizontal plane and the region showing the vertical detection result 22b can be easily generated with only one coordinate conversion process. Therefore, the horizontal detection result image 22 can be generated efficiently.

[0147] Also, a virtual direction θ (θ = 7, 9) is prepared in which a predetermined value CL is shown as the level of a virtual received signal for all distances in the distance direction. In the conversion table 16c, for each coordinate (X, Y) included in the region showing the vertical detection result 22b among the horizontal detection result images 22, the vertical direction (θ = 8), or a direction between the vertical direction and the virtual direction (7 ≤ θ < 8, 8 < θ ≤ 9) is associated. Then, for the coordinates (X, Y) associated with the direction between the vertical direction and the virtual direction (7 ≤ θ < 8, 8 < θ ≤ 9) in the conversion table 16c by the detection result image generation means 16, the level of the received signal in the vertical direction (θ = 8) and the predetermined value CL of the virtual direction (θ = 7, 9) are weighted-averaged based on the respective distances from the vertical direction (θ = 8) and the virtual direction (θ = 7, 9), thereby specifying the level of the received signal. As a result, the detection result image generation means 16 can display the detection result with a long length in the azimuth direction, which is a direction perpendicular to the distance direction, where the level (intensity) of the received signal is strong in the vertical direction (the direction of the second central axis C2), simply by specifying the level of the received signal according to the conversion table 16c. Therefore, while improving the processing efficiency, the depth at which a strong reaction occurred in the vertical direction (the direction of the second central axis C2) can be more clearly conveyed to the user.

[0148] As described above, the present invention has been described based on the embodiments. However, it can be easily inferred that the present invention is not limited to the above embodiments at all, and various improvements and modifications are possible without departing from the spirit of the present invention. For example, each embodiment may be configured by modifying the embodiment by adding a part or a plurality of parts of the configuration of another embodiment, including the modification examples described below, to the embodiment, or by exchanging a part or a plurality of parts of the configuration of the embodiment. Also, the numerical values given in the above embodiments are examples, and it is natural to adopt other numerical values.

[0149] In the above-described second embodiment, the case where elements in a virtual direction θ (θ = 7, 9) in which a predetermined value CL is shown as the level of a virtual reception signal for all distances in the distance direction are provided in the reception signal array 15b has been described. However, it is not always necessary to provide elements in the virtual direction θ (θ = 7, 9) in the reception signal array 15b. For example, a predetermined value CL to be adapted for all distances R in the virtual direction θ may be configured to be stored in a flash memory or a ROM provided in the control device 10. In this case, in the conversion table 16c, when a direction (7 ≦ θ < 8, 8 < θ ≦ 9) between the vertical direction and the virtual direction is associated with a certain coordinate (X, Y) included in the region indicating the detection result 22b in the vertical direction, the predetermined value CL, which is the level of the reception signal in the virtual direction, may be read from the flash memory or the ROM.

[0150] Also, only elements in one of the virtual directions θ (θ = 7, 9) in which a predetermined value CL is shown as the level of a virtual reception signal for all distances in the distance direction may be prepared in the reception signal array 15b. For example, when only elements in the virtual direction where the direction θ is "7" are prepared in the reception signal array 15b, and in the conversion table 16c, a decimal number where 8 < θ ≦ 9 is associated with a certain coordinate (X, Y) as the direction θ between the vertical direction and the virtual direction, elements in the virtual direction θ = 7 may be read from the reception signal array 15b instead of the virtual direction θ = 9.

[0151] In the above embodiment, the case where the first vibrators 52a to 52f are inclined and arranged with their acoustic radiation surfaces facing inward (toward the side where the second vibrator 53 is located) has been described. However, it is not necessarily limited to this. The first vibrators 52a to 52f may be inclined and arranged with their acoustic radiation surfaces facing outward (toward the side opposite to the side where the second vibrator 53 is located). Also in this case, the first central axes C1a to C1f may each form an angle selected from the range of 20° or more and 50° or less as a predetermined angle ω with respect to the second central axis C2 (the vertical direction when the transmission / reception wave unit 50 is attached to the ship 71).

[0152] In the above-described embodiment, the case where the first oscillators 52a to 52f are provided around the second oscillator 53 in the transmission / reception wave unit 50 has been described. However, regarding the arrangement method of the first oscillators 52a to 52f and the second oscillator 53 in the transmission / reception wave unit 50, overall, when the transmission / reception wave unit 50 is attached to the ship 71, the second central axis C2 is in the vertical direction, the first central axes C1a to C1f form a predetermined angle ω with respect to the second central axis C2 (in other words, the vertical direction), and as long as the first central axes C1a to C1f are in a predetermined direction, the arrangement positions of the first oscillators 52a to 52f and the second oscillator 53 may be arbitrary. For example, the first oscillators 52a to 52f and the second oscillator 53 may be arranged in a row or two rows, or the first oscillators 52a to 52f may be arranged in two rows, and the second oscillator 53 may be arranged at an arbitrary position between the two rows of the first oscillators 52a to 52f.

[0153] In the above-described embodiment, the case where detection is performed over a predetermined range set in all directions of the ship 71 has been described. However, the predetermined range may be one in which detection is performed over a predetermined range set for some azimuths among all directions of the ship 71.

[0154] In the above-described embodiment, the case where the number of the first oscillators 52 in the transmission / reception wave unit 50 is reduced, and ultrasonic waves TB are transmitted and received from the first oscillators 52 all at once over a predetermined range set in all directions of the ship 71 to perform horizontal detection has been described. However, the present invention in which the detection result image generation means 16 generates the horizontal detection result image 22 so as to show the vertical detection result 22b based on the reception signal of the reflected wave of the ultrasonic wave TB reflected from the vertical direction instead of the detection result 22a in the water projected onto a plane parallel to the horizontal plane in a region in a partial azimuth direction in the horizontal detection result image 22 is applicable to detection by a PPI sonar or a scanning sonar as well.

Explanation of Signs

[0155] 1 Ultrasonic sonar device 11a Transmission unit 11b Transmission unit 13a Receiver unit 13b Receiver unit 13c Receiver unit 13d Receiver unit 13e Receiver unit 13f Receiver unit 13g Receiver unit 14 Filter 15 Memory means 15a Received signal array 15b Received signal array 16 Detection result image generation means 16a Horizontal detection result image generation means 16b Vertical detection result image generation means 16c Conversion table 16c1 Horizontal detection conversion table section 16c2 Vertical detection conversion table section 18 Display control means 21 Display device 22 Horizontal detection result image 22a Detection result in water 22b Detection result in the vertical direction 50 Transmission and reception wave unit 52 First oscillator 52a First oscillator 52b First oscillator 52c First oscillator 52d First oscillator 52e First oscillator 52f First oscillator 53 Second oscillator 71 Ship C1 First central axis C1a First central axis C1b First central axis C1c First central axis C1d First central axis C1e First central axis C1f First central axis C2 Second central axis GF Detection target object TB Ultrasonic wave

Claims

1. A transceiver unit attached to a ship, configured to at least be able to transmit ultrasonic waves underwater over a predetermined range and receive reflected waves of the ultrasonic waves reflected from each position in the water for each predetermined direction including at least a plurality of directions set in the azimuth direction and the vertical direction; Receiving signal generation means for generating a receiving signal for each of the predetermined directions based on the reflected waves received by the transceiver unit; Detection result image generation means for generating a detection result image showing the detection result in the water projected onto a plane parallel to the horizontal plane based on the receiving signal generated by the receiving signal generation means at least in the direction set in the azimuth direction; Display means for displaying the detection result image generated by the detection result image generation means, comprising: The detection result image generation means generates the detection result image such that in a region of a part of the azimuth direction in the detection result image, instead of the detection result in the water projected onto a plane parallel to the horizontal plane, the detection result in the vertical direction based on the receiving signal generated by the receiving signal generation means in the vertical direction is displayed longer in a direction perpendicular to the distance direction as the intensity of the receiving signal is stronger. An ultrasonic sonar device characterized by this.

2. Storage means for storing the receiving signal generated by the receiving signal generation means for each of the predetermined directions in a receiving signal array indexed by the direction and the distance at which the reflected wave of the ultrasonic wave serving as the basis of the receiving signal is generated; The detection result image generation means, Has a conversion table showing the direction and the distance of the receiving signal array corresponding to each coordinate of the detection result image, Based on the conversion table, after specifying the level of the receiving signal at each coordinate of the detection result image from the receiving signal array, generates the detection result image, The conversion table, For each coordinate included in the region showing the detection result in the water projected onto a plane parallel to the horizontal plane in the detection result image, associates the direction set in the azimuth direction of the receiving signal array, The ultrasonic sonar device according to claim 1, characterized in that for each coordinate included in the region showing the detection result in the vertical direction in the detection result image, the vertical direction is associated.

3. A virtual direction is prepared in which a predetermined value is shown as the level of a virtual receiving signal for all distances in the distance direction, The conversion table associates, for each coordinate included in the region indicating the detection result in the vertical direction among the detection result images, a direction in the vertical direction or a direction between the vertical direction and the virtual direction. The ultrasonic sonar device according to claim 2, wherein the detection result image generation means specifies the level of the reception signal at the coordinate by weighted-averaging the level of the reception signal in the vertical direction and the predetermined value in the virtual direction for the coordinate associated with the direction between the vertical direction and the virtual direction in the conversion table, based on the respective distances from the vertical direction and the virtual direction.

4. A transceiver unit attached to a ship, configured to at least transmit ultrasonic waves into water over a predetermined range and receive reflected waves of the ultrasonic waves reflected from each position in the water for each predetermined direction including at least a plurality of directions set in the azimuth direction and the vertical direction. Reception signal generation means for generating a reception signal for each of the predetermined directions based on the reflected waves received by the transceiver unit. Storage means for storing the reception signals generated by the reception signal generation means for each of the predetermined directions in a reception signal array using the direction and the distance at which the reflected wave of the ultrasonic wave serving as the basis of the reception signal occurred as indexes. Detection result image generation means for generating a detection result image showing the detection result in the water projected onto a plane parallel to the horizontal plane based on at least the reception signals generated by the reception signal generation means in the directions set in the azimuth direction. Display means for displaying the detection result image generated by the detection result image generation means. A virtual direction is prepared in which a predetermined value is shown as the level of a virtual reception signal for all distances in the distance direction. The detection result image generation means has a conversion table showing the direction and the distance of the reception signal array corresponding to each coordinate of the detection result image, and based on the conversion table, after specifying the level of the reception signal at each coordinate of the detection result image from the reception signal array, the detection result image is generated so as to show, in a partial azimuth direction region of the detection result image, not the detection result in the water projected onto a plane parallel to the horizontal plane, but the detection result in the vertical direction based on the reception signal generated by the reception signal generation means in the vertical direction. The conversion table For each coordinate included in the region showing the detection result in water projected onto a plane parallel to the horizontal plane among the detection result images, associate the direction set in the azimuth direction of the received signal array. For each coordinate included in the region showing the detection result in the vertical direction among the detection result images, associate the vertical direction or a direction between the vertical direction and the virtual direction. The detection result image generation means weights and averages the level of the received signal in the vertical direction and the predetermined value in the virtual direction based on the respective distances from the vertical direction and the virtual direction for the coordinates associated with the direction between the vertical direction and the virtual direction in the conversion table, to specify the level of the received signal at the coordinates. The ultrasonic sonar device is characterized by this.

5. The detection result image generation means generates the detection result image such that the distance in the distance direction of the detection result in water projected onto a plane parallel to the horizontal plane is associated with the distance in the distance direction of the detection result in the vertical direction. The ultrasonic sonar device according to claim 1 or 4 is characterized by this.

6. The detection result image generation means generates the detection result image such that the detection result in the vertical direction is shown in the region corresponding to the rear side of the ship in the detection result image. The ultrasonic sonar device according to claim 1 or 4 is characterized by this.

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