ultrasonic sonar device

Abstract

The ultrasonic sonar device has a wave transmitting / receiving unit that has a plurality of transducers that transmit and receive ultrasonic waves in specific directions underwater, with the transducers installed so that the specific direction of each transducer is different. The device comprises: a detection result image generating means that generates a detection result image showing the detection results of a detection range set underwater by specifying the intensity of reflected waves from an underwater position corresponding to that pixel by performing a predetermined process using received signals of at least two specific directions out of the received signals stored in the storage means; a setting means that sets a failure determination mode for determining a failure; and an invalidating means that, when the failure determination mode is set by the setting means, executes an invalidating process to invalidate at least the predetermined process, and controls the detection result image generating means to specify, for each pixel of the detection result image, the intensity of the reflected waves from the position corresponding to that pixel using a received signal of one specific direction close to that position stored in the storage means.

Description

[Technical Field]

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

[0002] Ultrasonic sonar devices are known that use ultrasonic waves to detect targets, such as schools of fish, over a predetermined area underwater. While typical fish finders detect targets in a vertical direction from the ship, ultrasonic sonar devices detect targets around the ship using horizontal detection and vertical cross-sectional detection. Known ultrasonic sonar devices include PPI sonar (searchlight sonar) and scanning sonar.

[0003] PPI sonar emits (transmits) a thin beam of ultrasonic waves and receives the reflected waves from the object to be detected, using a single oscillator that is rotatable or pivotable, and performs underwater detection around the ship while changing the direction of ultrasonic wave emission (see, for example, Patent Document 1). PPI sonar can be constructed at low cost because the oscillator has a simple structure, but it takes time to complete a single detection over a specified range.

[0004] Scanning sonars form an array of multiple minute transducers on the surface of a cylinder, sphere, or the like, and simultaneously transmit ultrasonic waves from each transducer and receive the reflected waves, thereby performing simultaneous underwater detection around a ship (see, for example, Patent Document 2). While scanning sonars can perform a single detection over a predetermined range in a short time, the transducer array is complex and the transmitting and receiving circuits for transmitting and receiving ultrasonic waves in each transducer are large, making them expensive.

[0005] In response to this type of conventional ultrasonic sonar device, the inventors have invented a new type of ultrasonic sonar device (Patent Document 3). This new type of ultrasonic sonar device has 3 to 10 transducers with predetermined directional characteristics, and uses a wave transmission / reception unit that transmits ultrasonic waves over a predetermined range underwater at once using these transducers and can receive reflected waves of the ultrasonic waves reflected from various positions underwater in each specific direction. Each of the multiple first transducers is fixed so that its central axis is oriented in a specific direction, and has the predetermined directional characteristics so that it includes the central axes of at least adjacent transducers.

[0006] This new type of ultrasonic sonar device uses a small number of transducers to simultaneously transmit ultrasonic waves over a specified range and simultaneously receive the reflected waves to perform underwater detection. Furthermore, by reducing the number of transducers, the size of the transmission and reception circuitry for transmitting and receiving ultrasonic waves can be reduced.

[0007] On the other hand, this new type of ultrasonic sonar device uses the received signals for each specific direction generated based on the reflected waves received in each specific direction by each transducer, performs filtering in the azimuth and distance directions, and then performs interpolation. This allows the strength of the reflected ultrasonic waves from each position underwater to be estimated, making it possible to generate a detection result image with a predetermined resolution. Therefore, this new type of ultrasonic sonar device can perform underwater detection at high speed, capable of displaying a detection result image with a predetermined resolution, and can be constructed at low cost. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2019-066208 [Patent Document 2] Japanese Patent Application Publication No. 2019-200204 [Patent Document 3] Patent No. 7641685 Summary of the Invention [Problem to be solved by the invention]

[0009] Since PPI sonar performs underwater detection using a single transducer, any malfunctions such as transducer failure or circuit breaks will be displayed directly on the detection result image, making it possible to immediately identify any malfunctions.

[0010] However, in scanning sonars that use multiple transducers to perform underwater detection and the new ultrasonic sonar devices described above, the detection result image is generated by filtering and interpolating the received signals for each specific direction that are generated based on the reflected waves received in each specific direction by each transducer. As a result, even if a fault occurs in a transducer or circuit corresponding to a specific direction, it is difficult to determine from the detection result image which transducer or circuit corresponding to that specific direction has the fault, and it is even difficult to determine whether a fault has occurred at all.

[0011] The present invention has been made to solve the above problems, and aims to provide an ultrasonic sonar device that uses multiple transducers to detect a predetermined range underwater, and that allows malfunctions to be determined at a glance. [Means for solving the problem]

[0012] In order to achieve this object, a first aspect of the present invention is an ultrasonic sonar device comprising a wave transmitting / receiving unit having a plurality of transducers that transmit ultrasonic waves in a specific direction underwater and receive reflected waves of the ultrasonic waves reflected from various positions underwater as reflected waves in the specific direction, the transducers being arranged so that the specific direction of each transducer is different; received signal generating means that generates a received signal for each specific direction based on each transducer receiving the reflected wave in the specific direction of the transducer; storage means that stores the received signals generated by the received signal generating means for each specific direction; and a detection result image showing the detection results of a detection range set underwater, for each pixel of the detection result image, from the underwater position corresponding to that pixel. a detection result image generating means for specifying the intensity of the reflected wave by performing a predetermined process using at least two of the received signals from the specified direction among the received signals stored in the storage means, and generating the detection result image by assigning a mode for expressing the specified intensity of the reflected wave to the pixel; a setting means for setting a failure determination mode for determining a failure; and an invalidating means for, when the failure determination mode is set by the setting means, executing an invalidating process for invalidating at least the predetermined process, and controlling the detection result image generating means to specify, for each pixel of the detection result image, the intensity of the reflected wave from a position corresponding to that pixel using one received signal from the specified direction that is close to that position and stored in the storage means.

[0013] A second aspect of the present invention is the ultrasonic sonar device according to the first aspect, wherein the storage means stores the received signal generated by the received signal generation means for each of the specific directions in association with polar coordinates indicated by information corresponding to the direction and information corresponding to the distance to the position where the reflected wave that is the source of the received signal was generated, and the detection result image generation means specifies each pixel of the detection result image by orthogonal coordinates and includes a conversion table that associates the polar coordinates with the orthogonal coordinates of each pixel, and stores the intensity of the reflected wave from an underwater position corresponding to each pixel in the detection result image in association with the polar coordinates corresponding to the orthogonal coordinates of the pixel specified by the conversion table. The nullifying means performs the nullifying process by setting a virtual direction between adjacent specific directions and storing the received signals of the reflected waves from each position in the virtual direction as a predetermined fixed intensity in the storage means, and the detection result image generating means controls to identify, for each pixel of the detection result image, the intensity of the reflected waves from a position corresponding to the pixel using the received signal of one of the specific directions closest to the position stored in the storage means and the received signal of the virtual direction, with respect to polar coordinates corresponding to the Cartesian coordinates of the pixel specified by the conversion table.

[0014] A third aspect of the present invention is an ultrasonic sonar device according to the second aspect, wherein the received signal generating means applies a first filter to the received signal for each of the specific directions to generate a received signal assuming that ultrasonic waves are virtually transmitted and received in a virtual direction set between adjacent specific directions, the storage means stores the received signals generated by the received signal generating means for each of the specific directions and each of the virtual directions in association with the polar coordinates, the detection result image generating means identifies, for each pixel of the detection result image, the intensity of the reflected wave from an underwater position corresponding to that pixel by performing the predetermined processing using a received signal for one of the specific directions close to that position and a received signal for the virtual direction, which are stored in the storage means in association with polar coordinates corresponding to the orthogonal coordinates of the pixel identified by the conversion table, and the invalidating means executes, as the invalidating processing, a process of storing a predetermined fixed intensity for all of the received signals for the virtual directions stored in the storage means.

[0015] A fourth aspect of the present invention is an ultrasonic sonar device according to any one of the first to third aspects, wherein the received signal generating means applies a second filter to the original received signal obtained by each of the transducers receiving the reflected wave in the specific direction of the transducer to generate a received signal for each of the specific directions, and the disabling means, as the disabling processing, does not apply the second filter to the original received signal by the received signal generating means.

[0016] A fifth aspect of the present invention is an ultrasonic sonar device according to any one of the first to fourth aspects, wherein each of the plurality of transducers provided in the transmitting and receiving unit is fixed so that its central axis is in the specific direction, and has a predetermined directional characteristic so as to include at least the central axis of an adjacent transducer. [Effects of the Invention]

[0017] According to the ultrasonic sonar device of the first aspect of the present invention, ultrasonic waves are transmitted into water by multiple transducers provided in a wave transmitting / receiving unit, each in a different specific direction. The reflected waves of the ultrasonic waves reflected from each position in the water are received as reflected waves in the specific direction from which the ultrasonic waves were transmitted. Based on the reception of the reflected waves in the specific direction by each transducer, a received signal for each specific direction is generated by a received signal generating means, and the generated received signals are stored in a storage means for each specific direction. Then, a detection result image showing the detection results of the detection range set in the water is generated by a detection result image generating means as follows: For each pixel of the detection result image, the intensity of the reflected waves from the underwater position corresponding to that pixel is determined by performing predetermined processing using at least two of the received signals for specific directions stored in the storage means. Then, a detection result image is generated by assigning a mode representing the intensity of the determined reflected waves to that pixel. This allows a detection result image with a predetermined resolution to be presented to the user. On the other hand, when the setting means sets a failure determination mode for determining a failure, the disabling means executes a disabling process to disable at least the predetermined process in the detection result image generating means. The disabling means controls the detection result image generating means to determine, for each pixel of the detection result image, the intensity of the reflected wave from the position corresponding to that pixel using a received signal from one specific direction close to that position stored in the storage means. As a result, when the failure determination mode is set, each pixel of the detection result image does not reflect received signals from multiple specific directions, but only reflects a received signal from one specific direction close to the position corresponding to that pixel. Therefore, if a failure occurs in a transducer or circuit corresponding to a specific direction, the specific direction in which the failure occurs can be easily determined simply by looking at the detection result image. This has the effect of enabling a failure to be determined at a glance in an ultrasonic sonar device that uses multiple transducers to detect a specific underwater range.

[0018] The ultrasonic sonar device according to the second aspect of the present invention achieves the following effect in addition to the effect achieved by the ultrasonic sonar device according to the first aspect. Specifically, the received signal generated by the received signal generating means for each specific direction is stored in the storage means in association with polar coordinates indicated by information corresponding to the direction and information corresponding to the distance to the location where the reflected wave that is the source of the received signal was generated. The detection result image generating means identifies each pixel of the detection result image using Cartesian coordinates. Then, for each pixel of the detection result image, the intensity of the reflected wave from the underwater position corresponding to that pixel is identified using a conversion table. That is, the polar coordinates corresponding to the Cartesian coordinates of the specific pixel are identified using the conversion table. Then, the intensity of the reflected wave at that pixel is determined by performing a predetermined process on the identified polar coordinates using the received signals from two specific directions stored in the storage means. Meanwhile, when the setting means sets the failure determination mode, the disabling means sets a virtual direction between adjacent specific directions as a disabling process, and the received signals of the reflected waves from each position in the virtual direction are stored in the storage means as a predetermined fixed intensity. Then, in the detection result image generating means, when the polar coordinates corresponding to the orthogonal coordinates of each pixel of the detection result image are specified using the conversion table, the intensity of the reflected wave at that pixel is determined using the received signal in one specific direction close to the position stored in the storage means and the received signal in a virtual direction for the specified polar coordinates. This has the effect of making it possible to generate a detection result image that allows a failure to be determined at a glance in the failure determination mode without requiring a major change in processing from normal operations.

[0019] The ultrasonic sonar device according to the third aspect of the present invention achieves the following effect in addition to the effect achieved by the ultrasonic sonar device according to the second aspect. Specifically, the reception signal generating means applies a first filter to the reception signal for each specific direction to generate a reception signal that assumes that ultrasonic waves are virtually transmitted and received in a virtual direction set between adjacent specific directions. The reception signals generated by the reception signal generating means for each specific direction and each virtual direction are stored in a storage means associated with polar coordinates. The detection result image generating means then uses a conversion table to identify, for each pixel in the detection result image, the intensity of the reflected wave from the underwater position corresponding to that pixel. Specifically, the conversion table identifies the polar coordinates corresponding to the orthogonal coordinates of the pixel to be identified, and a predetermined process is performed using the reception signal for one specific direction close to that position and the reception signal for the virtual direction stored in the storage means for the identified polar coordinates to identify the intensity of the reflected wave at that pixel. As a result, the detection result image generating means can generate a detection result image using the conversion table not only the received signals in the specific direction but also the virtual received signals in the virtual direction set between adjacent specific directions, thereby improving the resolution in the direction in which the specific directions are aligned.On the other hand, when the failure determination mode is set by the setting means, the disabling means executes the process of storing predetermined fixed intensities for all received signals in the virtual directions stored in the storage means as disabling process.As a result, in the failure determination mode, by simply storing predetermined fixed intensities for all received signals in the virtual directions stored in the storage means, the detection result image generating means, while using the same conversion table as in normal mode, determines the intensity of the reflected wave from a position corresponding to each pixel in the detection result image using the received signal in one specific direction close to the position and the received signal in the virtual direction stored in the storage means for the polar coordinates corresponding to the Cartesian coordinates of the pixel specified by the conversion table. Therefore, under normal circumstances, a detection result image with improved resolution in the direction in which specific directions are aligned can be generated, while in the failure determination mode, a detection result image that allows a failure determination to be made at a glance can be generated using the same conversion table as under normal circumstances without requiring any significant changes to the processing from under normal circumstances.

[0020] The ultrasonic sonar device according to the fourth aspect of the present invention achieves the following effect in addition to the effect achieved by the ultrasonic sonar device according to any one of the first to third aspects. Specifically, the reception signal generating means applies a second filter to the original reception signal obtained by each transducer receiving a reflected wave from that transducer in a specific direction, thereby generating a reception signal for each specific direction. As a result, the detection result image generating means can generate a detection result image with more appropriate resolution by using the reception signal for each specific direction to which the second filter has been applied. Meanwhile, when the setting means sets the device to the failure determination mode, the disabling means performs a disabling process to disable application of the second filter to the original reception signal generated by the reception signal generating means. As a result, the detection result image generated by the detection result image generating means displays an image based on the reception signal to which the second filter has not been applied for each specific direction. Therefore, it is possible to clearly distinguish between specific directions in which a failure has occurred and specific directions in which no failure has occurred, thereby achieving the effect of generating a detection result image that makes it easier to determine whether a failure has occurred.

[0021] The ultrasonic sonar device according to the fifth aspect of the present invention achieves the following effect in addition to the effect achieved by the ultrasonic sonar device according to any one of the first to fourth aspects. Specifically, each of the multiple transducers provided in the wave transmitting / receiving unit is fixed so that its central axis is oriented in a specific direction and has a predetermined directional characteristic that includes the central axes of at least adjacent transducers. This allows ultrasonic waves to be transmitted simultaneously over a predetermined range using a small number of transducers, and the reflected waves can be received to detect a detection target. This has the effect of enabling an ultrasonic sonar device capable of high-speed detection to be constructed at low cost. Furthermore, even when underwater detection is performed using a small number of transducers, such an ultrasonic sonar device has the effect of being able to present a detection result image with a predetermined resolution to the user under normal conditions through predetermined processing, while in the failure detection mode, being able to determine a failure at a glance. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic diagram illustrating the configuration of an ultrasonic sonar device according to a first embodiment of the present invention. [Figure 2] 1 is a schematic side view showing a state in which underwater detection is performed by a ship equipped with the ultrasonic sonar device. FIG. [Figure 3] 1A is a schematic cross-sectional view showing the wave transmitting and receiving unit of the ultrasonic sonar device, and FIG. 1B is a schematic perspective view showing the arrangement of a plurality of first transducers and second transducers that make up the wave transmitting and receiving unit. [Figure 4] (a) is a diagram showing a schematic diagram of the first central axis of each of the first transducers when viewed vertically from above the ship, (b) is a diagram showing a schematic diagram of the first central axis when viewed horizontally from the front side of the ship, (c) is a diagram showing a schematic diagram of the directional characteristics of the ultrasound transmitted from the first transducer, and (d) is a diagram showing the directional characteristics of the ultrasound transmitted from the first transducer when viewed from the front side of the ship. [Figure 5] FIG. 2 is a block diagram showing the electrical configuration of the ultrasonic sonar device. [Figure 6] (a) is a diagram showing a schematic representation of the contents of the received signal array when the ultrasonic sonar device is operated in normal mode, and (b) is a diagram showing a schematic representation of the contents of the received signal array when the ultrasonic sonar device is operated in fault determination mode. [Figure 7] 3 is a diagram schematically showing a conversion table included in the detection result image generating means of the ultrasonic sonar device. FIG. [Figure 8] 10 is a flowchart showing a horizontal detection result image generation process executed by a control device of the ultrasonic sonar device. [Figure 9] 10 is a diagram showing an example of a horizontal detection result image displayed on the display device when the ultrasonic sonar device is in normal mode. FIG. [Figure 10] The figures show examples of horizontal detection result images displayed on the display device when the ultrasonic sonar device is in fault determination mode, where (a) shows the horizontal detection result image when there is no fault, and (b) shows the horizontal detection result image when a fault has occurred in one specific direction. [Figure 11] FIG. 10 is a block diagram showing the electrical configuration of an ultrasonic sonar device according to a second embodiment. [Figure 12] (a) is a diagram showing a schematic representation of the contents of the received signal array when the ultrasonic sonar device is operated in normal mode, and (b) is a diagram showing a schematic representation of the contents of the received signal array when the ultrasonic sonar device is operated in fault determination mode. [Figure 13] 10 is a flowchart showing a horizontal detection result image generation process executed by a control device of the ultrasonic sonar device. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Each of the embodiments described below illustrates a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component placement and connection configurations, 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, components that are not recited in the independent claims that represent the highest concept of the present invention will be described as optional components. Furthermore, in each drawing, substantially identical components are assigned the same reference numerals, and redundant explanations will be omitted or simplified.

[0024] (First embodiment) An ultrasonic sonar device 1 according to a first embodiment, which is one embodiment of the present invention, will be described with reference to Figures 1 to 10. First, Figure 1 is a schematic diagram showing the configuration of the ultrasonic sonar device 1, and Figure 2 is a schematic diagram showing a side view of a vessel 71 equipped with the ultrasonic sonar device 1 performing underwater detection.

[0025] 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 GF, such as a school of fish, over a predetermined range around the ship 71 in the waters of the sea, lake, river, or other area on which the ship 71 floats. Horizontal detection is performed by detecting a detection target GF within a predetermined range that is diagonally downward from the horizontal plane as viewed from the ship 71 and in all directions in the azimuth direction.

[0026] The predetermined range in which horizontal detection is performed does not necessarily have to be omnidirectional, but may be in a partial direction relative to the azimuth direction as viewed from the ship 71. The ultrasonic sonar device 1 may also have a sonar function that performs vertical cross-sectional detection in addition to or instead of horizontal detection. The ultrasonic sonar device 1 may also have a fish detection function that detects detection targets GF that exist in the vertical direction directly below the ship 71 and displays the detection results in a chronological order.

[0027] The ultrasonic sonar device 1 comprises a main body 5, an operation button 31 provided on the main body 5, a display device 21 as display means formed integrally with the main body 5, a wave transmitting and receiving unit 50 that transmits and receives ultrasonic waves TB for detecting a detection target GF, and an elevator 41 that raises and lowers the wave transmitting and receiving unit 50. The main body 5, operation button 31, and display device 21 are arranged in the wheelhouse of the ship 71, and the wave transmitting and receiving unit 50 and elevator 41 are arranged in the bottom of the ship 71.

[0028] The wave transmitting and receiving unit 50 is raised and lowered by the lifting device 41, so that it can freely appear and disappear underwater from the bottom of the ship 71. Note that the ultrasonic sonar device 1 does not necessarily have to have the lifting device 41, and the wave transmitting and receiving unit 50 may be fixed to the ship 71 at a position where it can transmit and receive ultrasonic waves TB into the water.

[0029] The operation button 31 is a button that can be operated by the user, and is operated when the user issues various instructions or settings to the ultrasonic sonar device 1. For example, the user operates the operation button 31 to turn the power of the ultrasonic sonar device 1 on / off, set the detection mode (horizontal detection, vertical cross-sectional detection, fish detection, etc.) and detection range of the ultrasonic sonar device 1, set the type and brightness of the image displayed by the display device 21, etc.

[0030] In addition, this embodiment has a failure determination mode for determining whether the ultrasonic sonar device 1 has a failure, and the user can turn this failure determination mode on or off by operating the operation button 31.

[0031] 2, the ultrasonic sonar device 1 transmits (radiates) ultrasonic waves TB in a cone shape within a predetermined range from the wave transmitting and receiving unit 50, with the wave transmitting and receiving unit 50 protruding from the bottom of the ship 71. The wave transmitting and receiving unit 50 is configured to be able to receive reflected waves of the ultrasonic waves TB reflected from a detection target GF within the predetermined cone-shaped range, the bottom of the sea or lake (hereinafter collectively referred to as the "bottom SB"), etc. The detailed configuration of the wave transmitting and receiving unit 50 will be described later with reference to FIGS. 3 and 4.

[0032] The display device 21 displays a detection result image, which is the detection result of the detection range set underwater, based on reception signals generated by receiving units 13a to 13g (described later) and a filter 15 (see FIG. 5) when the wave transmitting and receiving unit 50 receives reflected waves of the ultrasonic waves TB. The display device 21 is configured by, for example, a liquid crystal display or an organic EL (Electro-Luminescence) display.

[0033] Next, the detailed configuration of the wave transmitting and receiving unit 50 will be described with reference to Fig. 3 and Fig. 4. Fig. 3(a) is a schematic cross-sectional view showing the wave transmitting and receiving unit 50, and Fig. 3(b) is a schematic perspective view showing the arrangement of a plurality of first vibrators 52 (52a to 52f) and a second vibrator 53 that constitute the wave transmitting and receiving unit 50.

[0034] 4(a) is a diagram schematically showing the first center axes C1a to C1f of the first transducers 52a to 52f when viewed vertically from above the ship 71, and FIG. 4(b) is a diagram schematically showing the first center axes C1a to C1f of the first transducers 52a to 52f when viewed horizontally from the front side of the ship 71. FIG. 4(c) is a diagram schematically showing directional characteristics E1a, E1b, and E1f of ultrasonic waves TB transmitted from adjacent first transducers 52a, 52b, and 52f, and FIG. 4(d) is a diagram showing directional characteristics E1a and E1d of ultrasonic waves TB transmitted from the first transducers 52a and 52d, respectively, when viewed from the front side of the ship 71.

[0035] As shown in FIG. 3, the transmitting and receiving unit 50 has a structure in which a plurality of (six in the example shown in FIG. 3) first vibrators 52 (first vibrators 52a, first vibrators 52b, first vibrators 52c, first vibrators 52d, first vibrators 52e, first vibrators 52f) that transmit ultrasonic waves TB in a specific direction and receive the reflected waves, and a second vibrator 53 are molded and housed within a case 51.

[0036] Each of the first oscillators 52 corresponds to an oscillator of the present invention and is a disk-shaped structure having the same size and shape. Similarly to the first oscillators 52, the second oscillators 53 also have a disk-like shape. However, the size of the second oscillator 53 is determined according to the desired characteristics. That is, the second oscillator 53 may be the same size as the first oscillator 52 or may be a different size from the first oscillator 52.

[0037] 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 circular resin plate material that also serves as an acoustic matching layer, and is made of, for example, glass epoxy.

[0038] The piezoelectric element 55 is a plate-like object made of piezoelectric ceramic, and for example, a disk-shaped plate-like object made of lead zirconate titanate (PZT) is used. The piezoelectric element 55 has a front electrode (not shown) formed on its front surface, which is entirely bonded to the substrate 54 via an adhesive layer (not shown), and a back electrode (not shown) formed on its back surface opposite the front surface. Lead wires are electrically connected to the front electrode and the back electrode, respectively.

[0039] When a drive voltage is applied to the piezoelectric element 55 by a front electrode and a back electrode from the transmitting unit 11a or the transmitting unit 11b (see FIG. 5), which will be described later, the piezoelectric element 55 deforms in the thickness direction and vibrates the base material 54. This vibration of the base material 54 causes the first vibrator 52 and the second vibrator 53 to generate ultrasonic waves TB.

[0040] Furthermore, when the substrate 54 of each of the first oscillator 52 and the second oscillator 53 is vibrated by the reflected waves of the ultrasonic waves TB, the vibrations deform the piezoelectric element 55, generating a voltage between the front electrode and the back electrode. The first oscillators 52a to 52f and the second oscillator 53 output the voltage generated between the front electrode and the back electrode to the corresponding receiving units 13a to 13g, which will be described later, thereby generating a reception signal corresponding to the intensity of the reflected wave received by each of the first oscillators 52a to 52f and the second oscillator 53.

[0041] The case 51 has an opening at one end, and houses a plurality of first vibrators 52 and second vibrators 53 inside the case 51. The second vibrator 53 is disposed at the center of the case 51. Six first vibrators 52 are disposed around the second vibrator 53 in the order of first vibrator 52a, first vibrator 52b, first vibrator 52c, first vibrator 52d, first vibrator 52e, and first vibrator 52f, in a counterclockwise direction as viewed from the front surface of the base material 54. The acoustic radiation surfaces formed on the front surface of the base material 54 of each of the 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 a single imaginary spherical surface.

[0042] In this embodiment, the number of first oscillators 52 is six, but the number of first oscillators 52 may be any number of three or more, preferably four or more, and more preferably six or more. However, if the number of first oscillators 52 is large, the configuration of the ultrasonic sonar device 1 becomes complicated, larger, and more expensive, so the number of first oscillators 52 is preferably ten or less, and more preferably eight or less.

[0043] Here, the direction of the first oscillator 52a's first central axis C1a (which can also be considered the direction of the normal vector of the first oscillator 52a) is the central axis that is perpendicular to the center of the front surface (sound radiation surface) of the base material 54. Similarly to the first oscillator 52a, the first oscillator 52b is defined as having a first central axis C1b, the first oscillator 52c as having a first central axis C1c, the first oscillator 52d as having a first central axis C1d, the first oscillator 52e as having a first central axis C1e, and the first oscillator 52f as having a first central axis C1f. The first central axes C1b to C1f can be understood to be the sound radiation directions of the corresponding first oscillators 52b to 52f. That is, the first central axes C1a to C1f of the first oscillators 52a to 52f respectively correspond to specific directions in which the ultrasonic waves TB are transmitted within a predetermined range that is the detection range of the detection target GF.

[0044] Furthermore, the direction of the second central axis C2 (which can also be said to be the direction of the normal vector of the second oscillator 53), which is a central axis perpendicular to the center of the front surface (acoustic radiation surface) of the base material 54, can be understood to be the acoustic radiation direction of the second oscillator 53.

[0045] Here, the wave transmitting / receiving unit 50 is attached to the vessel 71 so that the direction of the second central axis C2 of the second transducer 53 is vertical. That is, the second transducer 53 transmits (radiates) ultrasonic waves TB in the vertical direction directly below the vessel 71. The presence of this second transducer 53 enables the ultrasonic sonar device 1 to detect the detection target GF in the vertical direction and / or measure the depth of the water bottom SB in the vertical direction with high accuracy. Note that the directional characteristics of the ultrasonic waves TB transmitted from the second transducer 53 are preferably a narrow beam with a small beam angle. This further increases the accuracy of detecting the detection target GF in the vertical direction and measuring the depth of the water bottom SB in the vertical direction.

[0046] 3, in the wave transmitting and receiving unit 50, the first transducers 52a to 52f are arranged with the sound emitting surface of each of the first transducers 52a to 52f inclined such that the first central axes C1a to C1f form a predetermined angle ω with respect to the second central axis C2 (i.e., the vertical direction when the wave transmitting and receiving unit 50 is attached to the ship 71). As a result, the sound emitting direction of each of the first transducers 52a to 52f is oriented in a direction different from the vertical direction directly below the ship 71, as shown in FIG. 4(b).

[0047] In this embodiment, the first transducers 52a to 52f are tilted with their acoustic radiation surfaces facing inward (toward the second transducer 53) (see FIG. 3). Preferably, each of the first central axes C1a to C1f forms a predetermined angle ω with respect to the second central axis C2, the predetermined angle ω being an angle selected from the range of 20° to 50°. In this embodiment, the predetermined angle ω is 30°. As shown in FIG. 3(a), the first central axes C1a to C1f and the second central axis C2 converge at one point.

[0048] 4(a), when the wave transmitting and receiving unit 50 is attached to the ship 71 and viewed vertically from above the ship 71, the first center axes C1a to C1f of the first transducers 52a to 52f are disposed at equal intervals in the azimuth direction so that the angles formed between adjacent first center axes C1a to C1f are the same angle δ. That is, the first transducers 52a to 52f are installed in the wave transmitting and receiving unit 50 so that the first center axes C1a to C1f (specific directions) of the first transducers 52a to 52f are different. When the number of first transducers 52 is n, the angle δ is (360 / n)° (when the number of first transducers 52 is six, the angle δ is 60°).

[0049] As a result, the wave transmitting and receiving unit 50 can simultaneously transmit ultrasonic waves TB in each specific direction indicated by the first central axes C1a to C1f by at least the first transducers 52a to 52f over a predetermined range set in all directions of the ship 71. Furthermore, the wave transmitting and receiving unit 50 receives, in response to the ultrasonic waves TB transmitted over the predetermined range by the first transducers 52a to 52f, reflected waves of the ultrasonic waves TB reflected from detection targets GF and the water bottom SB present at various positions underwater, by each of the first transducers 52a to 52f as reflected waves in the specific direction indicated by the corresponding first central axes C1a to C1f.

[0050] 4(a) and 4(b), when the ship 71 is viewed vertically from above, the wave transmitting and receiving unit 50 is attached to the ship 71 so that the first central axis C1a faces rightward with respect to the longitudinal direction of the ship 71, and the first central axes C1b to C1f are aligned counterclockwise from the first central axis C1a at intervals of an angle δ. In addition, in this embodiment, an example is shown in which the first transducers 52a to 52f are arranged so that the first central axes C1a to C1f of the first transducers 52a to 52f are equally spaced apart in the azimuth direction, but it is sufficient that ultrasonic waves TB can be simultaneously transmitted by at least the first transducers 52a to 52f in each specific direction indicated by the first central axes C1a to C1f over a predetermined range set in all azimuth directions of the ship 71, and the intervals between the first central axes C1a to C1f may vary.

[0051] The directional characteristics of the ultrasonic waves TB transmitted from each of the first transducers 52a to 52f are set to include the first central axes C1a to C1f of the adjacent first transducers 52. For example, as shown in Fig. 4(c), the directional characteristic E1a of the ultrasonic waves TB transmitted from the first transducer 52a is set to include the first central axis C1b of the adjacent first transducer 52b and the first central axis C1f of the first transducer 52f.

[0052] On the other hand, both the directional characteristic E1b of the ultrasonic waves TB transmitted from the first transducer 52b and the directional characteristic E1f of the ultrasonic waves TB transmitted from the first transducer 52f are set to include the first central axis C1a of the first transducer 52a. Although not shown, the directional characteristic E1b of the ultrasonic waves TB transmitted from the first transducer 52b is also set to include the first central axis C1c of the first transducer 52c that is adjacent to the first transducer 52a on the opposite side, and the directional characteristic E1f of the ultrasonic waves TB transmitted from the first transducer 52f is also set to include the first central axis C1e of the first transducer 52e that is adjacent to the first transducer 52a on the opposite side.

[0053] 4(d), the directional characteristic E1a of the ultrasonic waves TB transmitted from the first transducer 52a and the directional characteristic E1d of the ultrasonic waves TB transmitted from the first transducer 52d both include the vertical direction when the wave transmission and reception unit 50 is attached to the ship 71. Although not shown, the directional characteristics of the ultrasonic waves TB transmitted from the first transducers 52b, 52c, 52e, and 52f are also set to include the vertical direction when the wave transmission and reception unit 50 is attached to the ship 71, similar to the first transducers 52a and 52d.

[0054] As described above, the directivity of the ultrasonic waves TB transmitted from each of the first transducers 52a to 52f is set so as to include the first central axes C1a to C1f of the adjacent first transducers 52 and also to include the vertical direction when the transducer unit 50 is attached to the ship 71. As a result, by simultaneously driving each of the first transducers 52a to 52f, the transducer unit 50 irradiates ultrasonic waves TB from each of the first transducers 52a to 52f in the direction of the respective first central axes C1a to C1f, and due to the directivity of the ultrasonic waves TB, it is possible to simultaneously transmit the ultrasonic waves TB to a predetermined range set in all directions of the ship 71 using a small number of first transducers 52.

[0055] Furthermore, the directions of the first central axes C1a to C1f of the first transducers 52a to 52f and the directional characteristics of the ultrasonic waves TB emitted from the first transducers 52a to 52f are fixed so that the ultrasonic waves TB are emitted over a predetermined range from the wave transmitting and receiving unit 50. This eliminates the need for circuits for controlling the directions of the first central axes C1a to C1f of the first transducers 52a to 52f and circuits for controlling the directional characteristics of the ultrasonic waves TB emitted from the first transducers 52a to 52f.

[0056] The wave transmitting and receiving unit 50 receives the reflected waves of the ultrasonic waves TB reflected from the detection target GF and the water bottom SB present at various positions underwater within the predetermined range as reflected waves from the first central axes C1a to C1f, which are specific directions, using the first oscillators 52a to 52f corresponding to each of the first central axes C1a to C1f. As described above, the ultrasonic sonar device 1 can be constructed to perform high-speed detection in a small size and at low cost.

[0057] The wave transmitting / receiving unit 50 is arranged and housed in the case 51 with the first transducers 52a-52f and the second transducer 53 closely spaced so that the first central axes C1a-C1f and the second central axis C2 are oriented in the above-mentioned directions, and is fixed in place by a filler. This filler is made of a waterproof resin material (such as urethane resin) that has a lower specific acoustic impedance than the base material 54, which is the acoustic matching layer for the first transducers 52 and the second transducers 53. The filler is filled so that the outer surface is flush with the opening of the case 51, thereby sealing the opening of the case 51.

[0058] Next, the electrical configuration of the ultrasonic sonar device 1 will be described with reference to Fig. 5. Fig. 5 is a block diagram showing the electrical configuration of the ultrasonic sonar device 1. The ultrasonic sonar device 1 has a control device 10 inside its main body 5, which is provided with transmitting units 11a and 11b, diodes 12a to 12g, receiving units 13a to 13g, setting means 14, a filter 15, storage means 16, detection result image generating means 17, and display control means 18.

[0059] Each of the transmitting units 11a, 11b, receiving units 13a to 13g, setting means 14, filter 15, storage means 16, detection result image generating means 17, and display control means 18 may be configured as hardware, may be realized by software, or may be realized by a combination of hardware and software.

[0060] Although not shown, the control device 10 has a CPU (Central Processing Unit), which is an arithmetic device, a flash memory which is a rewritable non-volatile memory that stores programs executed by the CPU and fixed values ​​referenced by the 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 that temporarily stores various data when the CPU executes a program, and these are connected via a bus line.

[0061] Of the transmitting units 11a and 11b, receiving units 13a to 13g, setting means 14, filter 15, storage means 16, detection result image generating means 17, and display control means 18, those parts that are realized by software or by a combination of hardware and software are realized by the CPU executing a program. Also, a storage area for the failure determination mode flag 14a set by the setting means 14 is provided in flash memory or RAM. A storage area for the received signal array 16a stored by the storage means 16 is provided in RAM.

[0062] Based on instructions from the CPU, the transmission unit 11a generates one drive signal for transmitting ultrasound waves TB from the first transducers 52a to 52f. 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 transducers 52a to 52f. That is, after branching, one signal is input to the first transducer 52a via the diode 12a, one signal is input to the first transducer 52b via the diode 12b, one signal is input to the first transducer 52c via the diode 12c, one signal is input to the first transducer 52d via the diode 12d, one signal is input to the first transducer 52e via the diode 12e, and one signal is input to the first transducer 52f via the diode 12f.

[0063] The diodes 12a to 12f are elements that pass the drive signals generated by the transmitting unit 11a and input them to the corresponding first oscillators 52a to 52f, and also block the signals (voltages) generated by receiving reflected waves in each of the first oscillators 52a to 52f from being transmitted to the transmitting unit 11a or the branching points of the drive signals output from the transmitting unit 11a to each of the first oscillators 52a to 52f.

[0064] A single drive signal generated by the transmission unit 11a is branched and input to the first transducers 52a-52f via the diodes 12a-12f, so that the first transducers 52a-52f, which have the same shape and size, are driven simultaneously and can output ultrasonic waves TB of the same intensity at the same time. Therefore, ultrasonic waves TB can be transmitted uniformly in specific directions (i.e., directions of the first central axes C1a-C1f) included in a predetermined range set in all directions with respect to the ship 71, making it possible to make detection sensitivity uniform in all specific directions.

[0065] Furthermore, since one transmission unit 11a is provided for the plurality of first oscillators 52a to 52f, it is possible to achieve significant cost reduction and size reduction compared to the case where a transmission unit 11a is provided for each of the first oscillators 52a to 52f.

[0066] Furthermore, since the diodes 12a-12f are provided between the transmitting unit 11a and each of the first oscillators 52a-52f and downstream of the branching points where the drive signal output from the transmitting unit 11a branches toward each of the first oscillators 52a-52f, it is possible to prevent the signals (voltages) output by each of the first oscillators 52a-52f upon receiving the reflected waves of the ultrasonic waves TB from flowing back to the transmitting unit 11a or from entering the signal lines of the other first oscillators 52a-52f via the branching points, causing interference. Therefore, even if one transmitting unit 11a is provided for multiple (six) first oscillators 52a-52f, it is possible to ensure the independence of the signals (voltages) output from each of the first oscillators 52a-52f.

[0067] The transmitting unit 11b generates a drive signal for transmitting ultrasonic waves TB from the second oscillator 53 based on instructions from the CPU. The output of the drive signal generated by the transmitting unit 11b is input to the second oscillator 53 via a diode 12g. The diode 12g is an element that passes the drive signal generated by the transmitting unit 11b and inputs it to the second oscillator 53, and also blocks a signal (voltage) generated by receiving a reflected wave at the second oscillator 53 from being transmitted to the transmitting unit 11b. This diode 12g makes it possible to prevent the signal (voltage) output by the second oscillator 53 by receiving a reflected wave of the ultrasonic waves TB from flowing back to the transmitting unit 11b.

[0068] In the ultrasonic sonar device 1, the transmission unit 11b that generates a drive signal for the second transducer 53 that transmits ultrasonic waves TB in the vertical direction directly below the ship 71 is provided separately from the transmission unit 11a that generates drive signals for the first transducers 52a to 52f. This allows the ultrasonic sonar device 1 to function as a normal fish finder by turning off the transmission of ultrasonic waves TB from the first transducers 52a to 52f and transmitting ultrasonic waves TB only from the second transducer 53, or when performing horizontal detection as a sonar function, to control the transmission of ultrasonic waves TB from the second transducer 53 independently of the transmission of ultrasonic waves TB from the first transducers 52a to 52f.

[0069] In this embodiment, separate transmission units 11a corresponding to the first transducers 52a to 52f and transmission unit 11b corresponding to the second transducer 53 are provided, but if the specifications of the ultrasonic sonar device 1 are such that transmission of ultrasonic waves TB from the second transducer 53 can always be performed at the same timing as the first transducers 52a to 52f, then only one transmission unit 11a may be provided for the first transducers 52a to 52f and the second transducer 53, and one drive signal may be generated from this transmission unit 11a. This allows the ultrasonic sonar device 1 to be made even more compact and at a much lower cost.

[0070] The receiving units 13a to 13g are provided for each of the plurality (six) of first oscillators 52a to 52f and second oscillators 53. Each time a predetermined time has elapsed since the corresponding first oscillators 52a to 52f and second oscillators 53 transmitted ultrasonic waves TB, the receiving units 13a to 13g acquire signals (voltages) output in accordance with the intensities of the reflected waves of the ultrasonic waves TB received by the first oscillators 52a to 52f and second oscillators 53, and perform sampling to perform predetermined processing on the acquired signals.

[0071] That is, receiving unit 13a is connected to first oscillator 52a, and receives a signal (voltage) output by first oscillator 52a in accordance with the intensity of the reflected wave received, and performs predetermined processing on the signal. Further, receiving unit 13b is connected to first oscillator 52b, receiving unit 13c is connected to first oscillator 52c, receiving unit 13d is connected to first oscillator 52d, receiving unit 13e is connected to first oscillator 52e, receiving unit 13f is connected to first oscillator 52f, and receiving unit 13g is connected to second oscillator 53. Each of receiving units 13b to 13g also receives a signal (voltage) output by first oscillator 52b to 52f or second oscillator 53 in accordance with the intensity of the reflected wave received, and performs predetermined processing on the signal.

[0072] Each of the receiving units 13a to 13g has an amplifier circuit and an analog-to-digital converter circuit. Each of the receiving units 13a to 13g samples a signal (voltage) output from the corresponding first oscillator 52a to 52f or second oscillator 53 every time a predetermined time has elapsed after an ultrasonic wave TB is transmitted from the corresponding first oscillator 52a to 52f or second oscillator 53. Specifically, each of the receiving units 13a to 13g performs predetermined processing every time a predetermined time has elapsed by amplifying the signal (voltage) taken in from the corresponding first oscillator 52a to 52f or second oscillator 53 using an amplifier circuit, and then converts the amplified signal into a digital signal (digital value) with a predetermined number of bits (7 bits in this embodiment) using an analog-to-digital converter circuit (AD converter circuit).

[0073] The receiving unit 13a then outputs to the filter 15 the digital signal obtained by the AD conversion circuit, using the received signal (received signal of the reflected wave of the ultrasonic wave TB) received by the first oscillator 52a as the received signal of the reflected wave of the ultrasonic wave TB in the direction of the first center axis C1a. Similarly, the receiving unit 13b outputs to the filter 15 the digital signals obtained by the respective AD conversion circuits as the received signal of the reflected wave of the ultrasonic wave TB in the direction of the first center axis C1b of the first oscillator 52b, the receiving unit 13c outputs to the filter 15 the digital signals obtained by the received signal of the reflected wave of the ultrasonic wave TB in the direction of the first center axis C1c of the first oscillator 52c, the receiving unit 13d outputs to the filter 15 the digital signals obtained by the received signal of the reflected wave of the ultrasonic wave TB in the direction of the first center axis C1d of the first oscillator 52d, the receiving unit 13e outputs to the filter 15 the digital signals obtained by the received signal of the reflected wave of the ultrasonic wave TB in the direction of the first center axis C1e of the first oscillator 52e, the receiving unit 13f outputs to the filter 15 the digital signals obtained by the received signal of the reflected wave of the ultrasonic wave TB in the direction of the first center axis C1f of the first oscillator 52f, and the receiving unit 13g outputs to the filter 15 the digital signals obtained by the received signal of the reflected wave of the ultrasonic wave TB in the direction of the second center axis C2 of the second oscillator 53 (vertical direction).

[0074] As described above, the ultrasonic sonar device 1 provides one transmitting unit 11a for multiple (six) first transducers 52a to 52f to reduce costs and size, whereas the receiving units 13a to 13f are provided for each of the multiple first transducers 52a to 52f, allowing predetermined processing to be performed on each signal (voltage) while maintaining the independence of the signals (voltages) output from each of the first transducers 52a to 52f.

[0075] On the other hand, the ultrasonic sonar device 1 is configured with fewer transducers than conventional scanning sonars, so even if a receiving unit 13a to 13f is provided for each of the first transducers 52a to 52f, the entire receiving unit can be made smaller than conventional scanning sonars, thereby reducing costs.

[0076] The reception signals output from the reception units 13a to 13g are original reception signals that indicate the raw intensity values ​​of the reflected waves of the ultrasonic waves TB received by the corresponding first oscillators 52a to 52f and second oscillator 53. These original reception signals are reception signals before filtering by the filter 15, which will be described later.

[0077] The setting means 14 sets whether or not the ultrasonic sonar device 1 should operate in a failure determination mode for determining a failure, and has a failure determination mode flag 14a. The failure determination mode flag 14a is a flag that indicates whether or not the ultrasonic sonar device 1 should operate in the failure determination mode. That is, when the failure determination mode flag 14a is "1," the ultrasonic sonar device 1 operates in the failure determination mode, and when the failure determination mode flag 14a is "0," the ultrasonic sonar device 1 operates in a normal mode for normal underwater detection. The failure determination mode flag 14a is set to "0" as its initial value.

[0078] The setting of the failure determination mode by the setting means 14 is performed by the user of the ultrasonic sonar device 1 (or a repair person such as a service engineer) operating the operation button 31. When the ultrasonic sonar device 1 is in the normal mode (i.e., the failure determination mode flag 14a is "0"), if the user or the like operates the operation button 31 to instruct execution of the failure determination mode, the setting means 14 sets the failure determination mode flag 14a to "1." This causes the ultrasonic sonar device 1 to operate in the failure determination mode.

[0079] Furthermore, when the ultrasonic sonar device 1 is in the failure determination mode (i.e., the failure determination mode flag 14a is "1"), if the user or the like operates the operation button 31 to instruct execution of the normal mode, the setting means 14 sets the failure determination mode flag 14a to "0." This causes the ultrasonic sonar device 1 to return from the failure determination mode to the normal mode and operate.

[0080] The setting value of the failure determination mode flag 14a is input to the filter 15, the storage means 16, and the detection result image generation means 17. The filter 15, the storage means 16, and the detection result image generation means 17 operate according to the setting value of the failure determination mode flag 14a. That is, when the failure determination mode flag 14a is "0," the filter 15, the storage means 16, and the detection result image generation means 17 operate so that the ultrasonic sonar device 1 operates in normal mode. On the other hand, when the failure determination mode flag 14a is "1," the filter 15, the storage means 16, and the detection result image generation means 17 execute disable processing to disable operation in normal mode, and operate so that the ultrasonic sonar device 1 operates in failure determination mode. Details of these will be explained in the explanations of each component.

[0081] The filter 15 performs predetermined filtering on the received signals (original received signals) output from the receiving units 13a to 13g to the first oscillators 52a to 52f and the second oscillator 53. The predetermined filtering includes spatial filtering and may also include temporal filtering.

[0082] As for spatial filtering, filtering is performed in the azimuth direction and the distance direction on the original received signal of each of the first transducers 52a to 52f that receives the reflected wave of the ultrasonic wave TB for each specific direction, for the purpose of reducing noise and / or improving resolution, etc. The spatial filtering also includes filtering in the distance direction on the original received signal of the second transducer 53 that receives the reflected wave of the ultrasonic wave TB from the vertical direction directly below the ship 71.

[0083] Here, the azimuth direction is the direction in which the first central axes C1a to C1f of the first transducers 52a to 52f, i.e., the respective specific directions (acoustic emission directions), are aligned, in other words, it is a circumferential direction centered on the ship 71. Then, performing filtering in the azimuth direction means performing a filter operation on a received signal indicating the intensity of a reflected wave reflected from one distance (or depth) in one specific direction, using original received signals from the same distance (or depth) in multiple specific directions including (or excluding) that one specific direction.

[0084] The distance direction is the direction in which the ultrasonic waves TB are transmitted along the first central axes C1a to C1f of the first transducers 52a to 52f, respectively, and along the second central axis C2 of the second transducer 53, i.e., the respective acoustic emission directions themselves. Performing filtering in the distance direction means performing a filter operation on a received signal indicating the intensity of a reflected wave reflected from one distance (or depth) in one direction, using original received signals for multiple distances (or depths) including (or excluding) that one distance (or depth) in that one direction.

[0085] It should be noted that at least the spatial filtering process on the original reception signals of the first oscillators 52a to 52f, which is the filtering process in the azimuth direction, corresponds to the "second filter" of the present invention.

[0086] On the other hand, temporal filtering refers to filtering a received signal indicating the intensity of a reflected wave reflected from a certain distance (or depth) in a certain direction, together with at least one received signal received earlier in time and / or at least one received signal received later in time from the same direction and the same distance (or depth). This temporal filtering allows the horizontal detection result image 22, which will be described later and is displayed on the display device 21, to change smoothly over time, allowing the user to view the horizontal detection result image 22 without feeling any discomfort.

[0087] The filter 15 performs a predetermined filter process on the original reception signals of each of the first oscillators 52a to 52f and the second oscillator 53, and then stores the values ​​obtained by the filter process in the storage means 16 as reception signals of each of the first oscillators 52a to 52f and the second oscillator 53. The reception units 13a to 13g and the filter 15 correspond to reception signal generating means of the present invention.

[0088] The filter 15 performs the above-described filtering process when the failure determination mode flag 14a is "0," i.e., when the ultrasonic sonar device 1 is operating in normal mode. On the other hand, when the failure determination mode flag 14a is "1" and the ultrasonic sonar device 1 is operating in failure determination mode, the filter 15 does not apply some or all of the above-described filtering process. Specifically, the filter 15 does not apply azimuthal filtering, which is at least part of the spatial filtering process performed on the original received signals of the first oscillators 52a to 52f. This process of not applying filtering corresponds to one of the "invalidation processes" of the present invention, and the means for executing this process corresponds to one of the "invalidation means" of the present invention.

[0089] As a result, in the failure determination mode, it is possible to prevent the mixed-up of the received signals for each specific direction due to the filtering process in the azimuth direction. Therefore, as will be described in detail later, it is possible to prevent the mixed-up display of the received signals for a specific direction that is operating normally from being mixed with the pixels of the specific direction in which a failure has occurred in the horizontal detection result image 22 displayed on the display device 21, so that it is possible to determine at a glance from the horizontal detection result image 22 which specific direction in which a failure has occurred.

[0090] When the failure determination mode flag 14a is "1," the filter 15 may not only not apply the azimuth direction filtering process among the spatial filtering processes, but also not apply the distance direction filtering process. Furthermore, the filter 15 may also not apply the time direction filtering process, or may not apply all filtering processes performed by the filter 15.

[0091] The storage means 16 stores the filtered received signals of the first transducers 52a to 52f and the second transducer 53, generated by the filter 15, for each of the first transducers 52a to 52f and the second transducer 53 (i.e., in the directions of the first central axes C1a to C1f and the second central axis C2), in a received signal array 16a. As will be described next, the received signal array 16a has a different data structure when the ultrasonic sonar device 1 operates in normal mode and when it operates in fault determination mode.

[0092] First, referring to Figure 6(a), we will explain the contents of the received signal array 16a used when the failure determination mode flag 14a is "0" and the ultrasonic sonar device 1 operates in normal mode. Figure 6(a) is a diagram that schematically shows the contents of the received signal array 16a when the ultrasonic sonar device 1 is operated in normal mode.

[0093] The reception signal array 16a in the normal mode is a two-dimensional array that uses as indexes information θ corresponding to the specific direction in which the reflected wave of the ultrasonic wave TB that is the basis of the reception signal was received (i.e., the direction of each of the first center axes C1a to C1f and the direction of the second center axis C2; hereinafter referred to as "direction θ") and information R corresponding to the distance from the wave transmitting / receiving unit 50 to the position where the reflected wave of the ultrasonic wave that is the basis of the reception signal was generated (hereinafter referred to as "distance R"). In other words, the reception signal array 16a stores the intensity (level) of the reflected wave reflected from each position specified by polar coordinates consisting of the direction θ and the distance R as the level of the reception signal.

[0094] In the direction θ, the first center axes C1a to C1f, which are specific directions for receiving reflected waves of the ultrasonic waves TB set in the azimuth direction, are assigned numbers "1" to "6" 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 specific direction of the first center axis C1b. In the direction θ, "2" indicates the specific direction of the first center axis C1a. In the direction θ, "3" indicates the specific direction of the first center axis C1f. In the direction θ, "4" indicates the specific direction of the first center axis C1e. In the direction θ, "5" indicates the specific direction of the first center axis C1d. In the direction θ, "6" indicates the specific direction of the first center axis C1c.

[0095] Furthermore, the direction θ is assigned the number "7" for 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.

[0096] On the other hand, the numbers "1" to "200" are assigned to the distance R. Then, in the first transducers 52a to 52f or the second transducer 53 corresponding to each direction θ, sampling is performed by the corresponding receiving units 13a to 13g at predetermined time intervals after the ultrasonic wave TB is transmitted, and a received signal is output. Then, the numbers "1" to "200" are assigned to the output received signals one by one in ascending order. As is known, there is a proportional relationship between the time elapsed since the ultrasonic wave TB was transmitted and the distance to the position where the ultrasonic wave TB is reflected. Therefore, the distance R assigned in this manner can indicate the distance from the wave transmitting and receiving unit 50 to the position where the ultrasonic wave TB is reflected.

[0097] The memory means 16 stores the level RLn (n=θ+7×(R−1)) 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 16a.

[0098] For example, after a first transducer 52b, which transmits and receives ultrasonic waves TB in a specific direction of the first center axis C1b, transmits the ultrasonic waves TB, the level RL1 of the received signal after filtering by the filter 15 that is sampled for the first transducer 52b for the first time (first time) is stored in an element of the received signal array 16a indicated by an index of "1" for the direction θ and an index of "1" for the distance R. Furthermore, after a first transducer 52c, which transmits and receives ultrasonic waves TB in a specific direction of the first center axis C1c, transmits the ultrasonic waves TB, the level RL1399 of the received signal after filtering by the filter 15 that is sampled for the 200th time is stored in an element of the received signal array 16a indicated by an index of "6" for the direction θ and an index of "200" for the distance R.

[0099] Furthermore, after the second transducer 53, which transmits and receives ultrasonic waves TB in the direction of the second central axis C2 (vertical direction), transmits the ultrasonic waves TB, the level RL21 of the received signal after filtering by the filter 15 sampled third for the second transducer 53 is stored in the element of the received signal array 16a indicated by the index of "7" for the direction θ and "3" for the distance R.

[0100] The received signal array 16a shown in Figure 6(a) stored by this storage means 16 is referenced by the detection result image generation means 17, and a horizontal detection result image 22 showing the underwater detection results as shown in Figure 9 is generated by the method described below.

[0101] Next, referring to Fig. 6(b), the contents of the received signal array 16a used when the failure determination mode flag 14a is "1" and the ultrasonic sonar device 1 operates in the failure determination mode will be described. Fig. 6(b) is a diagram schematically showing the contents of the received signal array 16a when the ultrasonic sonar device 1 is executed in the failure determination mode.

[0102] The received signal array 16a in the failure determination mode is also a two-dimensional array with the direction θ and the distance R as indexes. The distance R is defined in the same way as the received signal array 16a in the normal mode. Meanwhile, the direction θ is defined by the directions of the first center axes C1a to C1f, the first to sixth virtual directions which are virtual directions set at intermediate positions between adjacent first center axes C1a to C1f, and the direction of the second center axis C2.

[0103] That is, for the direction θ, the numbers "1" to "12" are assigned clockwise from the front of the ship 71 when viewed vertically from above the ship 71 to each of the first center axes C1a to C1f, which are directions for receiving reflected waves of ultrasonic waves TB set in the azimuth direction, and the first to sixth virtual directions set at intermediate positions between adjacent first center axes C1a to C1f.

[0104] Specifically, "1" in the direction θ indicates a specific direction of the first central axis C1b. "2" in the direction θ indicates a first virtual direction (referred to as "virtual 1" in FIG. 6) set at a position midway between the first central axis C1b and the first central axis C1a. "3" in the direction θ indicates a specific direction of the first central axis C1a. "4" in the direction θ indicates a second virtual direction set at a position midway between the first central axis C1a and the first central axis C1f. "5" in the direction θ indicates a specific direction of the first central axis C1f. "6" in the direction θ indicates a third virtual direction set at a position midway between the first central axis C1f and the first central axis C1e.

[0105] In the direction θ, "7" indicates a specific direction of the first central axis C1e. "8" in the direction θ indicates a fourth virtual direction set at a position midway between the first central axis C1e and the first central axis C1d. "9" in the direction θ indicates a specific direction of the first central axis C1d. "10" in the direction θ indicates a fifth virtual direction set at a position midway between the first central axis C1d and the first central axis C1c. "11" in the direction θ indicates a specific direction of the first central axis C1c. "12" in the direction θ indicates a sixth virtual direction (referred to as "virtual 6" in Figure 6) set at a position midway between the first central axis C1c and the first central axis C1b.

[0106] Furthermore, the direction θ is assigned the number "13" with respect to the second central axis C2, which is the vertical direction. That is, in the direction θ, "13" indicates the direction of the second central axis C2.

[0107] In the failure determination mode, the storage means 16 stores the received signal of the reflected wave of the ultrasonic wave TB obtained from the specific direction of the first center axes C1a to C1f and the received signal of the reflected wave of the ultrasonic wave TB obtained from the direction of the second center axis C2 in the received signal array 16a of the corresponding direction θ. That is, the storage means 16 stores the level RLn (n=(θ+1) / 2+7×(R−1)) of the received signal of the reflected wave reflected from the position specified by the direction θ and the distance R in the specific direction of the first center axes C1a to C1f and the direction of the second center axis C2 in the element specified by the direction θ and the distance R in the received signal array 16a.

[0108] For example, after a first transducer 52b, which transmits and receives ultrasonic waves TB in a specific direction of the first center axis C1b, transmits the ultrasonic waves TB, a level RL1 of the received signal after filtering by the filter 15 that is sampled for the first transducer 52b for the first time (first time) is stored in an element of the received signal array 16a indicated by an index of "1" for the direction θ and an index of "1" for the distance R. Furthermore, after a first transducer 52c, which transmits and receives ultrasonic waves TB in a specific direction of the first center axis C1c, transmits the ultrasonic waves TB, a level RL1399 of the received signal after filtering by the filter 15 that is sampled for the 200th time is stored in an element of the received signal array 16a indicated by an index of "11" for the direction θ and an index of "200" for the distance R.

[0109] Furthermore, after the second transducer 53, which transmits and receives ultrasonic waves TB in the direction of the second central axis C2 (vertical direction), transmits the ultrasonic waves TB, the level RL21 of the received signal after filtering by the filter 15 sampled third for the second transducer 53 is stored in the element of the received signal array 16a indicated by the index of "13" for the direction θ and "3" for the distance R.

[0110] In the fault judgment mode, the received signals of the reflected waves of the ultrasonic waves TB obtained from a specific direction of the first center axes C1a to C1f and stored in the received signal array 16a are those to which at least azimuth filtering has not been applied, as described above.

[0111] On the other hand, the memory means 16 sets all received signals of reflected waves of ultrasonic waves TB from underwater positions specified at all distances R in directions θ (θ = 2, 4, 6, 8, 10, 12) corresponding to the first to sixth virtual directions in the received signal array 16a to a predetermined fixed intensity (zero in this embodiment), and stores the value of zero, which is the predetermined fixed intensity, for the elements specified by this direction θ and distance R.

[0112] When the ultrasonic sonar device 1 executes the failure determination mode, the received signal array 16a shown in Fig. 6(b) stored in the storage means 16 is referenced by the detection result image generation means 17, and a horizontal detection result image 22 such as that shown in Fig. 10 is generated by a method described later. Details will be described later, but in the failure determination mode, first to sixth virtual directions are set at intermediate positions between the first center axes C1a to C1f, and the received signals of the reflected waves of the ultrasonic waves TB in these virtual directions are set to a predetermined fixed intensity (zero), so that the intensity of the reflected waves of the ultrasonic waves TB from an underwater position corresponding to each pixel of the horizontal detection result image 22 can be determined using the received signal in one specific direction close to that position and the received signal in the virtual direction that has the predetermined fixed intensity (zero).

[0113] Therefore, the horizontal detection result image 22 can be generated that reflects only the received signals from each specific direction without mixing the received signals from two different specific directions, so that the specific direction in which the failure is occurring can be determined at a glance from the horizontal detection result image 22.

[0114] The process of setting the first to sixth virtual directions at intermediate positions between the first center axes C1a to C1f and setting the received signals of the reflected waves of the ultrasonic waves TB in these virtual directions to a predetermined fixed intensity (zero) corresponds to one of the "invalidation processes" of the present invention, and the means for executing this process corresponds to one of the "invalidation means" of the present invention.

[0115] Furthermore, in this embodiment, when the ultrasonic sonar device 1 executes the failure determination mode, the received signals of the reflected waves of the ultrasonic waves TB in the first to sixth virtual directions are all set to a predetermined fixed intensity of zero. However, this predetermined fixed intensity does not necessarily have to be zero and may be, for example, a value that is almost negligible as a level of the received signal. For example, in the detection result image generating means 17 described below, when generating the horizontal detection result image 22, a transparent color (or background color) may be assigned, or no color may be assigned, so that the predetermined fixed intensity is set within a range of the intensity of the reflected waves of the ultrasonic waves TB that does not visualize a reaction to the user (for example, a range of values ​​corresponding to an intensity of 0 dB to 46 dB). As a result, when the failure determination mode is set by the failure determination mode flag 14a of the setting means 14, the horizontal detection result image 22 can be displayed with an emphasized contrast between a specific direction in which a failure has occurred and a specific direction in which no failure has occurred. Therefore, a detection result image that makes it easy to determine whether a failure has occurred can be generated.

[0116] In this case, by increasing the predetermined fixed strength (approaching a value equivalent to the maximum value of the strength of the reflected waves of the ultrasonic waves TB that do not visualize a reaction to the user (46 dB in the above example)), the strength of the reflected waves from each specific direction actually received by the first transducers 52 a to 52 f can be significantly stretched in the azimuth direction (the circumferential direction of the horizontal detection result image 22) (see FIG. 10). This allows the reaction of each of the first transducers 52 a to 52 f to appear larger to the user (or a repair person such as a service engineer). On the other hand, by decreasing the predetermined fixed strength (i.e., by approaching a value equivalent to 0 dB), the stretching in the azimuth direction of the strength of the reflected waves from each specific direction actually received by the first transducers 52 a to 52 f can be reduced. Therefore, in the fault judgment mode, it is preferable that the predetermined fixed intensity be set from within a range of the intensity of the reflected wave of the ultrasonic wave TB that does not make the reaction visible to the user, so that the reaction (intensity of the received reflected wave) of each of the first transducers 52a to 52f shown in the horizontal detection result image 22 is easily visible to the user (or repair person).

[0117] The predetermined fixing strength may be configured to be changeable by the user (or repair person) operating the operation button 31. By making the predetermined fixing strength changeable, the user or the like can adjust the predetermined fixing strength so that the reaction of each of the first oscillators 52a to 52f can be easily seen in the horizontal detection result image 22 shown in Fig. 10 that is displayed in the failure determination mode.

[0118] Returning to Figure 5, the explanation will continue. In normal mode, the detection result image generating means 17 generates a detection result image to be displayed on the display device 21 based on the received signals for each specific direction of the first center axes C1a to C1f generated by the receiving units 13a to 13g and the filter 15, i.e., the received signal array 16a shown in Figure 6(a) stored in the storage means 16. When the ultrasonic sonar device 1 performs horizontal detection as a sonar function in normal mode, the detection result image generating means 17 generates at least a circular horizontal detection result image 22 as shown in Figure 9. This horizontal detection result image 22 corresponds to the "detection result image" of the present invention.

[0119] Furthermore, even in the failure determination mode, the detection result image generating means 17 generates at least the horizontal detection result image 22. However, in the failure determination mode, the detection result image generating means 17 generates at least the horizontal detection result image 22 to be displayed on the display device 21 based on the received signals of the first center axes C1a to C1f to which at least azimuth filtering has not been applied by the filter 15 and the received signals for each of the first to sixth virtual directions in which zero is stored as a predetermined fixed intensity, that is, based on the received signal array 16a shown in Fig. 6(b) stored in the storage means 16. However, the horizontal detection result image 22 generated in the failure determination mode is an image as shown in Fig. 10, as will be described later.

[0120] In both the normal mode and the failure determination mode, the detection result image generating means 17 manages and identifies each pixel of the horizontal detection result image 22 in a Cartesian coordinate system consisting of an X coordinate and a Y coordinate. As shown in Fig. 7, the detection result image generating means 17 has conversion tables 17a and 17b that associate Cartesian coordinates (X, Y) indicating each pixel of the horizontal detection result image 22 with coordinates (R, θ) in a polar coordinate system consisting of a direction θ and a distance R, which are indexes of the received signal array 16a corresponding to the coordinates (X, Y). Fig. 7 is a schematic diagram showing the contents of the conversion tables 17a and 17b.

[0121] As described above, the polar coordinates (R, θ) of the received signal array 16a in the normal mode and the polar coordinates (R, θ) of the received signal array 16a in the failure determination mode have different definitions of the direction θ. Therefore, the detection result image generating means 17 has a normal conversion table 17a used in the normal mode and a failure determination conversion table 17b used in the failure determination mode.

[0122] The directions θ associated in the normal conversion table 17a are in the range of 1≦θ<7. Here, a direction indicated by 6≦θ<7 means a direction included between the direction θ indicated by "6" (first center axis C1c) and the direction θ indicated by "1" (direction of the first center axis C1b). In other words, in this normal conversion table 17a, only the direction θ indicating an azimuth direction is associated, and the direction θ indicating a vertical direction (θ=7) is excluded.

[0123] On the other hand, the directions θ associated in the fault determination conversion table 17b are 1≦θ<13. Here, the directions indicated by 12≦θ<13 refer to directions included between the direction θ indicated by "12" (the sixth virtual direction) and the direction θ indicated by "1" (the direction of the first center axis C1b). In the same way as the normal conversion table 17a, this fault determination conversion table 17b also associates only the direction θ that is the azimuthal direction, and excludes the direction θ that indicates the vertical direction (θ=13).

[0124] The detection result image generating means 17 uses the normal conversion table 17a or the failure determination conversion table 17b to identify, for each pixel of the horizontal detection result image 22, the coordinates (R, θ) in the polar coordinate system corresponding to the coordinates (X, Y) of that pixel. Then, for each pixel, the detection result image generating means 17 identifies the level of the received signal at the position of the coordinates (R, θ) identified for that pixel from the received signal array 16a stored in the storage means 16, and sets the identified received signal level as the intensity of the reflected wave from the underwater position corresponding to that pixel. In this way, the detection result image generating means 17 can identify, for each pixel of the horizontal detection result image 22, which shows the underwater detection result projected onto a plane parallel to the horizontal plane, the intensity of the reflected wave from the underwater position corresponding to that pixel, from the level of the received signal in the azimuth direction stored in the received signal array 16a.

[0125] Here, the direction θ and distance R, which are coordinates in the polar coordinate system corresponding to the coordinates (X, Y), are not necessarily natural numbers used as indices in the received signal array 16a, but are often expressed as decimals. In this case, the received signal level at the coordinate (R, θ) is determined by calculating a weighted average of the received signal levels of four elements of the received signal array 16a that are close to the coordinate (R, θ) expressed as a decimal. The weighted average is calculated so that the received signal level of the element of the received signal array 16a that is closest to the coordinate (R, θ) is largely reflected.

[0126] For example, the level of the received signal at the position of coordinates (R, θ) = (49.8, 2.3) is calculated by taking a weighted average of the received signal levels of the elements of the received signal array 16a indicated by the respective indexes (R, θ) = (49, 2), (49, 3), (50, 2), and (50, 3).

[0127] In the normal conversion table 17a, the level of the received signal at the position of coordinates (R, θ) = (19.6.7) is calculated by taking a weighted average of the levels of the received signals of the elements of the received signal array 16a indicated by the indexes (R, θ) = (19,6), (19,1), (20,6), and (20,1). The index "1" is used as the direction θ because, clockwise, the direction indicated by direction θ = "6" is adjacent to the direction indicated by direction θ = "1".

[0128] On the other hand, in the case of the fault determination conversion table 17b, the level of the received signal at the position of coordinates (R, θ) = (19.6.7) is calculated by taking a weighted average of the levels of the received signals of the elements of the received signal array 16a indicated by the respective indexes (R, θ) = (19,6), (19,7), (20,6), and (20,7). In contrast, the level of the received signal at the position of coordinates (R, θ) = (119.6, 12.4) is calculated by taking a weighted average of the levels of the received signals of the elements of the received signal array 16a indicated by the respective indexes (R, θ) = (119,12), (119,1), (120,12), and (120,1). This is because, in the fault determination mode, the direction indicated by the direction θ = "1" is next to the direction indicated by the direction θ = "12" in the clockwise direction.

[0129] The detection result image generating means 17, upon identifying the intensity of the reflected wave from the underwater position corresponding to each pixel, generates a horizontal detection result image 22 by assigning a color according to the intensity of the reflected wave. This "color" corresponds to the "aspect of expressing the intensity of the reflected wave" of the present invention. The detection result image generating means 17 may represent the identified intensity of the reflected wave with shading or with a different graphic pattern.

[0130] In this way, the detection result image generating means 17 generates the horizontal detection result image 22 using the normal conversion table 17a in the normal mode and the failure determination conversion table 17b in the failure determination mode.

[0131] Here, as shown in Fig. 6(a), the received signal array 16a in the normal mode has an azimuth direction θ that is configured only in the specific direction of the first center axes C1a to C1f. In the normal mode, the detection result image generating means 17 performs coordinate conversion using the normal conversion table 17a based on the levels of the received signals stored in this received signal array 16a, and the intensity of the reflected wave from each pixel of the horizontal detection result image 22 is determined by interpolation processing using received signals from two specific directions that sandwich the underwater position indicated by that pixel. This interpolation processing using received signals from two specific directions corresponds to the "predetermined processing" of the present invention.

[0132] On the other hand, as shown in Fig. 6(b), the received signal array 16a in the failure determination mode has an azimuth direction θ composed of specific directions of the first center axes C1a to C1f and first to sixth virtual directions (virtual directions) set between these specific directions. A predetermined fixed intensity (zero in this embodiment) is stored in each virtual direction for all elements indicated by the distance R. In the failure determination mode, the detection result image generating means 17 performs coordinate conversion using the failure determination conversion table 17b based on the levels of the received signals stored in the received signal array 16a, thereby determining the intensity of the reflected wave from each pixel of the horizontal detection result image 22 by interpolating the received signal from one specific direction close to the underwater position indicated by the pixel and the received signal from one virtual direction to which a predetermined fixed intensity is set. This makes it possible to generate a horizontal detection result image 22 that reflects only the received signals from each specific direction without mixing the received signals from two different specific directions, so that the specific direction in which the failure is occurring can be determined at a glance from the horizontal detection result image 22.

[0133] In the failure judgment mode, the intensity of the reflected wave of each pixel of the horizontal detection result image 22 is determined not by an interpolation process using received signals in two specific directions, but by disabling the interpolation process and performing an interpolation process using a received signal in one specific direction and a received signal in one virtual direction with a predetermined fixed intensity set, which corresponds to one of the "disabling processes" of the present invention, and the means for performing this corresponds to one of the "disabling means" of the present invention.

[0134] The display control means 18 performs control to display the horizontal detection result image 22 generated by the detection result image generation means 17 and other images on the display device 21. 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 combines characters, symbols, figures, etc. with the horizontal detection result image 22, etc., to display one image on the display device 21.

[0135] Next, a method for performing horizontal detection using the sonar function of the ultrasonic sonar device 1 of this embodiment configured as described above will be described, mainly with reference to Fig. 8, but also with reference to Figs. 1, 2, and 5. Fig. 8 is a flowchart showing the horizontal detection result image generation process executed by the control device 10. The horizontal detection result image generation process is a process for performing one underwater horizontal detection by transmitting and receiving ultrasonic waves TB, and generating a horizontal detection result image 22 that shows the detection results of that one underwater horizontal detection.

[0136] Note that, here, we will explain an example in which the ultrasonic sonar device 1 performs horizontal detection, but in each step of the horizontal detection result image generation process described below, by replacing "horizontal detection" with "vertical cross-sectional detection," the present invention can also be applied to cases in which the ultrasonic sonar device 1 performs vertical cross-sectional detection.

[0137] When the user turns on the power to the ultrasonic sonar device 1 via the operation button 31, or when an instruction is given to start performing horizontal detection using the sonar function while the power is on, the ultrasonic sonar device 1 first drives the lifting device 41 to make the wave transmitting and receiving unit 50 appear in the water from the bottom of the ship 71. Note that in an ultrasonic sonar device 1 that does not have the lifting device 41 and in which the wave transmitting and receiving unit 50 is fixed to the ship 71 in a position where it can transmit and receive ultrasonic waves TB into the water, the driving operation of the lifting device 41 is omitted.

[0138] The ultrasonic sonar device 1 then executes the horizontal detection result image generation process at predetermined time intervals by the control device 10 until the power is turned off or the user issues an instruction to end horizontal detection using the sonar function by operating the operation button 31. The predetermined time is set in the range of, for example, 10 milliseconds to 1 second depending on the width or depth of the predetermined range for underwater detection set in advance by the user.

[0139] In addition, while the ultrasonic sonar device 1 is performing underwater detection, it accepts operation of the operation button 31 from the user and performs processing corresponding to the operation button 31, such as setting a predetermined range for horizontal detection and setting a failure determination mode.

[0140] For example, if the failure determination mode flag 14a of the setting means 14 is "0" and the user operates the operation button 31 to set the failure determination mode while horizontal detection is being performed in normal mode, the control device 10 will use the setting means 14 to set the failure determination mode flag 14a to "1" and cause the ultrasonic sonar device 1 to perform horizontal detection in the failure determination mode.

[0141] On the other hand, if the failure determination mode flag 14a of the setting means 14 is "1" and the user operates the operation button 31 to set the normal mode while horizontal detection is being performed in the failure determination mode, the control device 10 sets the failure determination mode flag 14a to "0" using the setting means 14 and operates the ultrasonic sonar device 1 in the normal mode.

[0142] 8, when the control device 10 starts executing the horizontal detection result image generation process, first, as shown in Fig. 8, the control device 10 outputs drive signals from the transmitting unit 11a and the transmitting unit 11b, and transmits ultrasonic waves TB from the first transducers 52a to 52f and the second transducer 53 of the wave transmitting and receiving unit 50 in the specific directions of the first center axes C1a to C1f and the second center axis C2, respectively (S1). Due to the directional characteristics of the ultrasonic waves TB transmitted from the specific directions of the first center axes C1a to C1f, the ultrasonic waves TB are transmitted in all directions to the ship 71.

[0143] In the process of S1, the transmission unit 11b may not output a drive signal, and ultrasonic waves TB may not be transmitted from the second transducer 53 in the direction of the second central axis C2. By transmitting ultrasonic waves TB from at least the first transducers 52a to 52f in the specific directions of the first central axes C1a to C1f, the ultrasonic sonar device 1 can perform horizontal detection in all directions.

[0144] However, by also transmitting ultrasonic waves TB in the direction of the second central axis C2, the ultrasonic sonar device 1 can perform, in addition to horizontal detection, a fish detection function that displays the detection results of the detection target GF located in the vertical direction from the ship 71 in chronological order, and a function that accurately measures the depth of the bottom SB directly below the ship 71 in the vertical direction.

[0145] The ultrasonic waves TB transmitted from the first oscillators 52a to 52f and the second oscillator 53 are reflected from the detection target GF and the water bottom SB present at various positions within a predetermined range underwater through which the ultrasonic waves TB are transmitted. The reflected waves are received by the first oscillators 52a to 52f and the second oscillator 53, and signals (voltages) are output from the first oscillators 52a to 52f and the second oscillator 53 as the intensities of the reflected waves received in the specific directions of the first central axes C1a to C1f and the direction of the second central axis C2.

[0146] After transmitting ultrasonic waves TB through the process of S1, the control device 10 amplifies the signals (voltages) output by the first oscillators 52a-52f and the second oscillator 53 by receiving reflected waves of the ultrasonic waves TB reflected from various positions in the water using receiving units 13a-13g provided corresponding to the first oscillators 52a-52f and the second oscillator 53, respectively, converts the signals into 7-bit digital signals (digital values), and samples them (S2). The receiving units 13a-13g output the digital signals obtained by sampling as original received signals in the specific directions of the corresponding first center axes C1a-C1f and the direction of the second center axis C2.

[0147] After the process of S2, the control device 10 executes different processes depending on the value of the failure determination mode flag 14a set by the setting means 14. That is, the control device 10 references the value of the failure determination mode flag 14a and determines whether or not the control device 10 is in the failure determination mode (S3). As a result, if the value of the failure determination mode flag 14a is "0" and the control device 10 determines that the control device 10 is in the normal mode (S3: No), the control device 10 executes the processes of S4 to S6.

[0148] First, the control device 10 performs spatial (and temporal) filtering using the filter 15 on the original received signals output from the receiving units 13a-13g in the specific directions of the first center axes C1a-C1f and the direction of the second center axis C2 (S4). As described above, spatial filtering includes filtering performed in the azimuth direction on the original received signals for each specific direction of the first center axes C1a-C1f. That is, through the filtering process of S4, a received signal for one specific direction is generated by mixing the original received signals for multiple specific directions. This can reduce noise and / or improve resolution.

[0149] Next, the control device 10 stores the levels of the received signals in each specific direction of the first center axes C1a to C1f and in the direction of the second center axis C2 after filtering by the filter 15 in the processing of S4 in each element of the received signal array 16a of the storage means 16, which is specified by the polar coordinates (R, θ) of the direction θ, which is an index indicating the direction, and the distance R, which is an index indicating the distance to the underwater position where the reflected wave indicated by the received signal was reflected, as shown in Figure 6(a) (S5).

[0150] The control device 10 then generates a horizontal detection result image 22 using the detection result image generation means 17 (S6). Specifically, the control device 10 uses the normal conversion table 17a to identify, for each pixel in the horizontal detection result image 22, the polar coordinates (R, θ) corresponding to the Cartesian coordinates (X, Y) of that pixel. The control device 10 then weighted-averages the levels of the received signals stored in each element of the received signal array 16a near the identified polar coordinates (R, θ) to identify the intensity of the reflected wave from the underwater position corresponding to the pixel indicated by the Cartesian coordinates (X, Y). The control device 10 then generates the horizontal detection result image 22 by assigning a color according to the intensity of the reflected wave from the underwater position corresponding to that pixel, identified for each pixel.

[0151] Thereafter, the control device 10 causes the display control means 18 to display the horizontal detection result image 22 generated in the process of S6 and other images on the display device 21 (S7), and ends the horizontal detection result image generation process.

[0152] 9 is a diagram showing an example of a horizontal detection result image 22 displayed on the display device 21 when the ultrasonic sonar device 1 is in normal mode. As described above, the ultrasonic sonar device 1 performs spatial (and temporal) filtering on the original received signals in each specific direction of the first central axes C1a to C1f using the filter 15. The ultrasonic sonar device 1 then stores the levels of the received signals in each specific direction after filtering in the received signal array 16a in the storage means 16 as shown in FIG. 6(a), and by using the normal conversion table 17a, the intensity of the reflected wave from each pixel of the horizontal detection result image 22 is determined by interpolation using the received signals in two specific directions that sandwich the underwater position indicated by that pixel.

[0153] As a result, when the ultrasonic sonar device 1 is in normal mode, as shown in Figure 9, it can display a horizontal detection result image 22, which is a horizontal detection result image having a predetermined resolution over a predetermined range that is the detection range, on the display device 21 and present it to the user.

[0154] Returning to Fig. 8, the description of the horizontal detection result image generation process will continue. In the judgment of S3, when the control device 10 judges that the value of the failure judgment mode flag 14a is "1" and that it is in the failure judgment mode (S3: Yes), it executes the processes of S8 to S10.

[0155] First, the control device 10 does not apply at least azimuth filtering by the filter 15 to the original received signals in each specific direction of the first center axes C1a to C1f and the direction of the second center axis C2 output from the receiving units 13a to 13g, and then, as shown in Figure 6(b), stores the levels of the received signals in each specific direction of the first center axes C1a to C1f and the direction of the second center axis C2 in each element of the received signal array 16a of the storage means 16, which is specified by the polar coordinates (R, θ) of the direction θ, which is an index indicating the direction, and the distance R, which is an index indicating the distance to the underwater position where the reflected wave indicated by the received signal was reflected (S8).

[0156] In this case, the level of the received signal in the specific direction of the first center axis C1b is stored in the element for direction θ="1", the level of the received signal in the specific direction of the first center axis C1a is stored in the element for direction θ="3", the level of the received signal in the specific direction of the first center axis C1f is stored in the element for direction θ="5", the level of the received signal in the specific direction of the first center axis C1e is stored in the element for direction θ="7", the level of the received signal in the specific direction of the first center axis C1d is stored in the element for direction θ="9", and the level of the received signal in the specific direction of the first center axis C1c is stored in the element for direction θ="11". In addition, the level of the received signal in the direction of the second center axis C2 is stored in the element for direction θ="13".

[0157] Next, the control device 10 sets virtual directions (first virtual direction to sixth virtual direction) at the midpoint between adjacent specific directions for each specific direction indicated by the first central axes C1a to C1f, and stores a value of zero, which is a predetermined fixed intensity, as the level of the virtual received signal from the underwater position corresponding to the direction θ and distance R for elements of the received signal array 16a identified at all distances R in the direction θ (θ = 2, 4, 6, 8, 10, 12) corresponding to the first virtual direction to the sixth virtual direction, as shown in Figure 6(b) (S9).

[0158] At this time, a first virtual direction to which the direction θ="2" is assigned is set between the first central axis C1b and the first central axis C1a, a second virtual direction to which the direction θ="4" is assigned is set between the first central axis C1a and the first central axis C1f, a third virtual direction to which the direction θ="6" is assigned is set between the first central axis C1f and the first central axis C1e, a fourth virtual direction to which the direction θ="8" is assigned is set between the first central axis C1e and the first central axis C1d, a fifth virtual direction to which the direction θ="10" is assigned is set between the first central axis C1d and the first central axis C1c, and a sixth virtual direction to which the direction θ="12" is assigned is set between the first central axis C1c and the first central axis C1b.

[0159] Then, the control device 10 uses the failure determination conversion table 17b to generate a horizontal detection result image 22 by the detection result image generation means 17 (S10). Specifically, the control device 10 uses the failure determination conversion table 17b to identify the intensity of the reflected wave from the underwater position corresponding to each pixel of the horizontal detection result image 22 specified by the Cartesian coordinates (X, Y) based on the level of the received signal stored in each element of the received signal array 16a specified by the polar coordinates (R, θ). The control device 10 then generates the horizontal detection result image 22 by assigning a color according to the intensity of the reflected wave from the underwater position corresponding to each pixel specified for that pixel.

[0160] Thereafter, the control device 10 proceeds to processing S7, and causes the display control means 18 to display the horizontal detection result image 22 generated in the processing of S10 and other images on the display device 21 (S7), thereby terminating the horizontal detection result image generation processing.

[0161] Here, Figure 10 shows an example of a horizontal detection result image 22 displayed on the display device 21 when the ultrasonic sonar device 1 is in fault judgment mode, where (a) shows the horizontal detection result image 22 when there is no fault, and (b) shows the horizontal detection result image 22 when a fault has occurred in one specific direction.

[0162] As described above, the ultrasonic sonar device 1 does not apply at least azimuth-direction filtering to the original received signals in each specific direction of the first center axes C1a to C1f by the filter 15, and then stores the levels of the received signals in each specific direction in directions θ = 1, 3, 5, 7, 9, and 11 of the received signal array 16a in the storage means 16. The ultrasonic sonar device 1 also sets virtual directions (first virtual direction to sixth virtual direction) at positions midway between adjacent specific directions in the received signal array 16a as directions θ = 2, 4, 6, 8, 10, and 12, and stores a predetermined fixed intensity (zero in this embodiment) as the level of the virtual received signal from the virtual direction. The ultrasonic sonar device 1 then generates the horizontal detection result image 22 using the fault determination conversion table 17b corresponding to the thus configured received signal array 16a (i.e., the received signal array 16a in which the direction θ representing the azimuth direction is indicated by 1 to 12).

[0163] As a result, the ultrasonic sonar device 1 determines the intensity of the reflected wave from each pixel of the horizontal detection result image 22 by interpolating the received signal from one specific direction close to the underwater position indicated by that pixel and the received signal from one virtual direction with a predetermined fixed intensity. Furthermore, the received signal from this specific direction is one to which at least azimuth filtering has not been applied. This makes it possible to generate a horizontal detection result image 22 as shown in FIG. 10, which reflects only the received signals from each specific direction, without mixing the received signals from two different specific directions.

[0164] If no fault occurs in any specific direction, responses appear in all of those specific directions in the horizontal detection result image 22, as shown in Fig. 10(a). On the other hand, if a fault occurs in a specific direction, responses appear in the horizontal detection result image 22 in the specific direction in which no fault occurs, as shown in Fig. 10(b), but no response appears in the specific direction in which the fault occurs (diagonally downward to the left from the center in Fig. 10(b)). Therefore, in the fault determination mode, the specific direction in which the fault occurs can be determined at a glance from the horizontal detection result image 22 generated as described above.

[0165] Furthermore, in this embodiment, in the failure determination mode, the strength of the reflected waves from each pixel of the horizontal detection result image 22 is determined by interpolation using a received signal from one specific direction close to the underwater position indicated by that pixel and a received signal from one virtual direction with a predetermined fixed strength. Therefore, the strength of the reflected waves from each specific direction actually received by the first transducers 52a-52f can be extended in the azimuth direction (circumferential direction of the horizontal detection result image 22) as shown in FIG. 10. Therefore, in the failure determination mode, the horizontal detection result image 22 displays responses from specific directions where no failure has occurred as long in the azimuth direction (circumferential direction), emphasizing that the reflected waves are being received normally. This allows the user to more clearly distinguish these from specific directions where a failure has occurred and no response is displayed.

[0166] The ultrasonic sonar device 1 according to the first embodiment described above provides the following advantageous effects.

[0167] (1) The plurality of first transducers 52a-52f provided in the wave transmitting / receiving unit 50 transmit ultrasonic waves TB in different specific directions (the directions of the first central axes C1a-C1f) into the water, and the reflected waves of the ultrasonic waves TB reflected from various positions in the water are received as reflected waves in the specific directions from which the ultrasonic waves TB were transmitted. Based on the reception of the reflected waves in the specific directions (the directions of the first central axes C1a-C1f) by each of the first transducers 52a-52f, received signals for each specific direction are generated by the receiving units 13a-13f and the filter 15, and the generated received signals are stored in the received signal array 16a of the storage means 16 for each specific direction. Then, the detection result image generating means 17 generates a horizontal detection result image 22 showing the detection results of the detection range set in the water as follows: That is, for each pixel of the horizontal detection result image 22, the strength of the reflected waves from the underwater position corresponding to that pixel is determined by performing interpolation processing using received signals from at least two specific directions among the received signals stored in the received signal array 16a of the storage means 16. Then, the horizontal detection result image 22 is generated by assigning different colors to the pixel as a mode of expressing the strength of the determined reflected waves. In this way, the horizontal detection result image 22 with a predetermined resolution can be presented to the user.

[0168] On the other hand, when the failure determination mode flag 14a of the setting means 14 is set to a failure determination mode for determining a failure, a disable process is executed to disable the interpolation process using the received signals from two specific directions in the detection result image generating means 17. Then, the detection result image generating means 17 is controlled to determine, for each pixel of the horizontal detection result image 22, the intensity of the reflected wave from the position corresponding to that pixel using the received signal from one specific direction close to that position stored in the received signal array 16a of the storage means 16. As a result, when the failure determination mode is set, each pixel of the horizontal detection result image 22 reflects only the received signal from one specific direction close to the position corresponding to that pixel, rather than reflecting the received signals from multiple specific directions. Therefore, if a failure occurs in the first transducers 52a-52f or circuit corresponding to a specific direction, it is easy to determine which specific direction the failure occurs in simply by looking at the horizontal detection result image 22. Therefore, in the ultrasonic sonar device 1 that performs detection within a predetermined underwater range using multiple first transducers 52a-52f, a failure can be determined at a glance.

[0169] (2) For each specific direction indicated by the first center axes C1a to C1f, the received signals generated by the receiving units 13a to 13f and the filter 15 are stored in the received signal array 16a of the storage means 16 in association with polar coordinates (R, θ) indicated by the direction θ, which is information corresponding to that direction, and the distance R, which is information corresponding to the distance to the position where the reflected wave that is the source of the received signal was generated. The detection result image generation means 17 also identifies each pixel of the horizontal detection result image 22 by Cartesian coordinates (X, Y). Then, for each pixel of the horizontal detection result image 22, the intensity of the reflected wave from the underwater position corresponding to that pixel is identified using the normal conversion table 17a. That is, the polar coordinates (R, θ) corresponding to the Cartesian coordinates (X, Y) of the specific pixel are identified by the normal conversion table 17a. Then, by performing interpolation processing on the identified polar coordinates (R, θ) using the received signals from two specific directions stored in the received signal array 16a of the storage means 16, the intensity of the reflected wave at that pixel is identified.

[0170] On the other hand, when the failure determination mode is set by the failure determination mode flag 14a of the setting means 14, virtual directions (first to sixth virtual directions) are set between adjacent specific directions (first center axes C1a to C1f) as an invalidation process by the invalidation means, and the received signals of reflected waves from each position in the virtual directions are stored as a predetermined fixed intensity in the received signal array 16a of the storage means 16. Then, in the detection result image generation means 17, when the polar coordinates (R, θ) corresponding to the Cartesian coordinates (X, Y) of each pixel in the horizontal detection result image 22 are identified by the failure determination conversion table 17b, the intensity of the reflected waves at that pixel is identified using the received signal of one specific direction close to that position stored in the received signal array 16a of the storage means 16 for the identified polar coordinates (R, θ) and the received signal of the virtual direction. As a result, in the failure determination mode, it is possible to generate a horizontal detection result image 22 that allows for a failure determination at a glance without requiring a significant change in processing from normal operations.

[0171] (3) In the normal mode, the filter 15 applies spatial (and temporal) filtering to the original received signals obtained by each of the first oscillators 52a to 52f receiving the reflected waves in the specific directions indicated by the corresponding first center axes C1a to C1f, thereby generating received signals for each specific direction. As a result, the detection result image generating means 17 can generate the horizontal detection result image 22 with more appropriate resolution by using the received signals for each specific direction to which this spatial (and temporal) filtering has been applied.

[0172] On the other hand, when the failure determination mode is set by the failure determination mode flag 14a of the setting means 14, the disabling process by the disabling means is to not apply at least spatial filtering in the azimuth direction to the original received signals for each specific direction by the filter 15. As a result, an image based on received signals to which at least spatial filtering in the azimuth direction has not been applied appears for each specific direction in the horizontal detection result image 22 generated by the detection result image generating means 17. Therefore, it is possible to clearly distinguish between specific directions in which a failure has occurred and specific directions in which no failure has occurred, and it is possible to generate a horizontal detection result image 22 that makes it easier to determine whether a failure has occurred.

[0173] (4) Each of the multiple first transducers 52a-52f provided in the wave transmitting / receiving unit 50 is fixed so that its first central axis C1a-C1f is oriented in a specific direction and has a predetermined directional characteristic that includes the central axis of at least adjacent first transducers 52a-52f. This allows the small number of first transducers 52a-52f to simultaneously transmit ultrasonic waves TB over a predetermined range and receive the reflected waves to detect the detection target GF. This has the effect of allowing an ultrasonic sonar device 1 capable of high-speed detection to be constructed at low cost. Furthermore, with such an ultrasonic sonar device 1, even when underwater detection is performed using a small number of first transducers 52a-52f, a horizontal detection result image 22 with a predetermined resolution can be presented to the user through filter processing during normal operation, while in the failure detection mode, failure detection can be performed at a glance.

[0174] (Second embodiment) Next, an ultrasonic sonar device 1 according to a second embodiment of the present invention will be described with reference to FIGS.

[0175] In the ultrasonic sonar device 1 according to the second embodiment, the received signal array 16a stored in the storage means 16 in the normal mode has the same data structure as the received signal array 16a in the failure determination mode according to the first embodiment. That is, even in the normal mode, virtual directions (first virtual direction to sixth virtual direction) are set at midpoints between the specific directions indicated by the first center axes C1a to C1f. However, in the normal mode, the intensities of the reflected waves from each underwater position in the first virtual direction to the sixth virtual direction are calculated by applying a predetermined filter process to the specific directions on both sides, and stored in the received signal array 16a. On the other hand, in the failure determination mode, as in the first embodiment, the intensities of the reflected waves from each underwater position in the first virtual direction to the sixth virtual direction are stored in the received signal array 16a, assuming that they are a predetermined fixed intensity (zero).

[0176] Furthermore, in the ultrasonic sonar device 1 according to the second embodiment, since the structure of the received signal array 16a is the same in the normal mode and the fault judgment mode, the same conversion table 17c is used in the detection result image generating means 17 when generating the horizontal detection result image 22 from the received signal array 16a in the normal mode and the fault judgment mode.

[0177] The ultrasonic sonar device 1 according to the second embodiment will be described below, focusing on the differences from the ultrasonic sonar device 1 according to the first embodiment. The same components as those in the ultrasonic sonar device 1 according to the first embodiment will be assigned the same reference numerals, and their description will be omitted or simplified.

[0178] Fig. 11 is a block diagram showing the electrical configuration of the ultrasonic sonar device 1 according to the second embodiment. Fig. 12(a) is a diagram showing a schematic representation of the contents of the received signal array 16a when the ultrasonic sonar device 1 is operated in the normal mode, and Fig. 12(b) is a diagram showing a schematic representation of the contents of the received signal array 16a when the ultrasonic sonar device 1 is operated in the failure determination mode.

[0179] When performing horizontal detection using the sonar function, the ultrasonic sonar device 1 performs detection using a small number of transducers, first transducers 52a to 52f (six in this embodiment), which results in a significant decrease in azimuth resolution (azimuth resolution). Therefore, in the ultrasonic sonar device 1 according to the second embodiment, when performing horizontal detection in the normal mode in which the failure determination mode flag 14a of the setting means 14 is set to "0," the filter 15 performs the following predetermined filter processing in addition to the filter processing described in the first embodiment.

[0180] That is, the filter 15 sets a virtual direction at a midpoint between adjacent first central axes C1a-C1f of the first transducers 52a-52f, which are specific directions in which the ultrasonic wave TB is transmitted and received. The filter 15 then applies predetermined filter processing to the received signals of the first transducers 52a-52f to generate virtual received signals that would occur if the ultrasonic wave TB (hereinafter referred to as a "virtual beam") were virtually transmitted and received in the set virtual direction.

[0181] An example of the predetermined filtering process will now be described. Assuming that a virtual beam virtually transmitted in one virtual direction is reflected at a position at a distance R from the wave transmitting / receiving unit 50, the filter 15 calculates the level VL(R) of the received signal (hereinafter referred to as "received signal VL(R) in the virtual direction"), which indicates the intensity of the reflected wave, as follows:

[0182] First, the filter 15 calculates the absolute value DRL of the difference between the two received signals, which correspond to the intensity of the reflected waves reflected at a position at a distance R from the wave transmitting / receiving unit 50, for two first center axes C1a to C1f adjacent in the azimuth direction to the virtual direction to be calculated (hereinafter referred to as "received signals RL1(R) and RL2(R) in adjacent specific directions"). That is, the absolute value DRL of the difference between the received signals is calculated by the following equation (1).

[0183] DRL = |RL1(R)-RL2(R)| … (1) For the reception signals RL1(R) and RL2(R) in the specific directions on either side, the level of the original reception signal in each specific direction of the first center axes C1a to C1f may be used as is, or the level of the reception signal after applying the spatial (and temporal) filtering process described in the first embodiment to the original reception signal may be used.

[0184] Next, the filter 15 subtracts half the absolute value DRL of the difference between the received signals from the adjacent specific directions, RL1(R) and RL2(R), as shown in the following equations (2) and (3).

[0185] RL1(R)=RL1(R)-DRL / 2 …(2) RL2(R)=RL2(R)-DRL / 2 …(3) On the other hand, the filter 15 calculates the average value of the received signals RL1(R) and RL2(R) in the specific directions on both sides using the following equation (4), and then adds half the absolute value DRL of the difference to this average value to obtain the received signal VL(R) in the virtual direction. Note that the received signals RL1(R) and RL2(R) in the specific directions on both sides used in equation (4) are values ​​before applying equations (2) and (3).

[0186] VL(R)=(RL1(R)+RL2(R)) / 2+DRL / 2 …(4) In this way, the filter 15 generates the received signal VL(R) in the virtual direction by applying the filter processing expressed by equations (1) to (4) to the received signals RL1(R) and RL2(R) in the specific directions on both sides of the virtual direction. This filter processing corresponds to the "first filter" of the present invention.

[0187] As a result, by generating not only reception signals in the directions of the first center axes C1a to C1f along which the ultrasonic waves TB are actually transmitted and received by the first oscillators 52, but also virtual reception signals in virtual directions intermediate between the first center axes C1a to C1f, the number of directions along which the ultrasonic waves TB are transmitted and received can be increased (in this embodiment, double the number, 12 directions) including the virtual directions to be greater than the actual number of first oscillators 52 (i.e., the number of predetermined directions). Thus, the ultrasonic sonar device 1 can display the horizontal detection result image 22 with improved azimuth resolution.

[0188] In addition, the filter 15 moves a portion of each of the received signals RL1(R) and RL2(R) from the specific directions on either side to the received signal VL(R) in the virtual direction using equations (1) to (4).

[0189] If the received signal VL(R) in the virtual direction is generated by simple interpolation, such as taking the average value of the received signals RL1(R) and RL2(R) in specific directions on either side, the total energy within the screen of the horizontal detection result image 22 may become greater than the total energy of the reflected waves received by the first transducers 52a to 52f.

[0190] In contrast, by applying the predetermined filter processing shown in equations (1) to (4), even if the received signal VL(R) in the virtual direction is generated, the horizontal detection result image 22 can be generated while maintaining the total energy of the reflected waves received by the first transducers 52a to 52f. That is, the ultrasonic sonar device 1 applies a predetermined filter processing that can maintain the total energy of the received reflected waves to the received signals from each of the first transducers 52a to 52f that transmit and receive ultrasonic waves TB in the specific direction of the first center axes C1a to C1f, thereby generating received signals that assume that a virtual beam is transmitted and received in a virtual direction set between the specific directions. This prevents the total energy in the screen from increasing beyond the total energy of the received reflected waves, even if a virtual received signal in the virtual direction is generated. Therefore, by inserting the received signal in the virtual direction into the horizontal detection result image 22, the ultrasonic sonar device 1 can prevent the horizontal detection result image 22 from showing a higher level of response than the actual detection result.

[0191] On the other hand, when the filter 15 is in the failure determination mode in which the failure determination mode flag 14a of the setting means 14 is set to "1", as in the first embodiment, the filter 15 not only does not apply the azimuthal filtering process among at least the spatial filtering processes to the original reception signals of the first transducer 52a to the first transducer 52f, but also does not apply the predetermined filtering processes shown in equations (1) to (4).

[0192] As a result, the filter 15 does not set virtual directions (first virtual direction to sixth virtual direction) at positions midway between adjacent first center axes C1a to C1f, which are specific directions, and does not generate virtual received signals assuming that virtual beams are transmitted and received in each virtual direction.

[0193] Non-application of the specified filter processing shown in equations (1) to (4) also corresponds to one of the "invalidation processes" of the present invention, and the means for non-application of the specified filter processing shown in equations (1) to (4) also corresponds to one of the "invalidation means" of the present invention.

[0194] Next, in the second embodiment, the data structure of the received signal array 16a stored in the storage means 16 is the same as that of the received signal array 16a in the failure judgment mode in the first embodiment, whether the setting means 14 is in the normal mode with the failure judgment mode flag 14a set to "0" or in the failure judgment mode with the failure judgment mode flag 14a set to "1".

[0195] That is, the received signal array 16a is a two-dimensional array with indexes of the direction θ (i.e., the specific direction of each of the first central axes C1a to C1f, the first to sixth virtual directions set at intermediate positions between adjacent first central axes C1a to C1f, and the direction of the second central axis C2), which is information corresponding to the direction in which the reflected wave of the ultrasonic wave TB that is the basis of the received signal was received, including the above-mentioned virtual direction, and the distance R, which is information corresponding to the distance from the wave transmitting and receiving unit 50 to the position where the reflected wave of the ultrasonic wave that is the basis of the received signal was generated. That is, the received signal array 16a stores the intensity (level) of the reflected wave reflected from each position specified by polar coordinates consisting of the direction θ and the distance R, as the level of the received signal.

[0196] In the second embodiment, as shown in Figure 12, in both the normal mode and the failure judgment mode, the direction θ is assigned numbers "1" to "12" clockwise from the front of the ship 71 when viewed vertically from above the ship 71 for each of the specific directions indicated by the first center axes C1a to C1f set in the azimuth direction and each of the first to sixth virtual directions set at intermediate positions between adjacent first center axes C1a to C1f.

[0197] Specifically, the direction θ="1" indicates a specific direction of the first central axis C1b. The direction θ="2" indicates a first virtual direction (referred to as "Virtual 1" in FIG. 12) set at a position midway between the first central axis C1b and the first central axis C1a. The direction θ="3" indicates a specific direction of the first central axis C1a. The direction θ="4" indicates a second virtual direction set at a position midway between the first central axis C1a and the first central axis C1f. The direction θ="5" indicates a specific direction of the first central axis C1f. The direction θ="6" indicates a third virtual direction set at a position midway between the first central axis C1f and the first central axis C1e. The direction θ="7" indicates a specific direction of the first central axis C1e. The direction θ="8" indicates a fourth virtual direction set at a position midway between the first central axis C1e and the first central axis C1d. The direction θ="9" indicates a specific direction of the first central axis C1d. The direction θ="10" indicates a fifth virtual direction set at a position midway between the first central axis C1d and the first central axis C1c. The direction θ="11" indicates a specific direction of the first central axis C1c. The direction θ="12" indicates a sixth virtual direction (referred to as "virtual 6" in FIG. 6) set at a position midway between the first central axis C1c and the first central axis C1b.

[0198] Furthermore, the direction θ is assigned the number "13" with respect to the second central axis C2, which is the vertical direction. That is, in the direction θ, "13" indicates the direction of the second central axis C2.

[0199] Further, the distance R is assigned a number between "1" and "200" as information indicating the distance from the transmitting / receiving unit 50 to the position where the reflected wave of the ultrasonic wave that is the source of the received signal was generated, in the same manner as in the first embodiment.

[0200] In the normal mode, the storage means 16 stores the received signals of the reflected waves of the ultrasonic waves TB obtained from the specific direction of the first central axes C1a to C1f and the received signals of the reflected waves of the ultrasonic waves TB obtained from the direction of the second central axis C2 in the received signal array 16a of the corresponding direction θ (θ=1, 3, 5, 7, 9, 11, 13) after spatial (and temporal) filtering has been applied by the filter 15. That is, the storage means 16 stores the level RLn (n=(θ+1) / 2+7×(R−1)) of the received signals of the reflected waves reflected from the position specified by the direction θ and the distance R in the specific direction of the first central axes C1a to C1f and the direction of the second central axis C2 in the element specified by the direction θ and the distance R in the received signal array 16a.

[0201] In addition, in the normal mode, the storage means 16 stores the levels of the received signals of the virtual reflected waves in the first to sixth virtual directions, which are generated by applying the predetermined filter processing shown in the above equations (1) to (4) to the received signals in each specific direction indicated by the first center axes C1a to C1f by the filter 15, in the received signal array 16a for the corresponding direction θ (θ=2, 4, 6, 8, 10, 12). That is, the storage means 16 stores the levels VLn (n=θ / 2+7×(R−1)) of the received signals of the reflected waves virtually reflected from the position specified by the direction θ and the distance R in the first to sixth virtual directions in the element specified by the direction θ and the distance R in the received signal array 16a.

[0202] On the other hand, in the failure judgment mode, as shown in Figure 12(b), the storage means 16 stores the received signals of the reflected waves of the ultrasonic waves TB obtained from specific directions of the first center axes C1a to C1f and the received signals of the reflected waves of the ultrasonic waves TB obtained from the direction of the second center axis C2 in the received signal array 16a of the corresponding direction θ (θ = 1, 3, 5, 7, 9, 11, 13) in the same manner as in the normal mode, after spatial (and temporal) filtering processing is applied by the filter 15.

[0203] On the other hand, in the failure determination mode, the storage means 16 sets the received signals of the reflected waves of the ultrasonic waves TB from underwater positions specified at all distances R in the directions θ (θ=2, 4, 6, 8, 10, 12) corresponding to the first to sixth virtual directions in the received signal array 16a to a predetermined fixed intensity (zero in this embodiment), as in the first embodiment. That is, the storage means 16 stores the value of zero, which is the predetermined fixed intensity, in the elements of all distances R for the directions θ corresponding to the first to sixth virtual directions. The process of setting the received signals of the reflected waves of the ultrasonic waves TB in these virtual directions to a predetermined fixed intensity (zero) corresponds to one of the "invalidation processes" of the present invention, and the means for executing this process corresponds to one of the "invalidation means" of the present invention.

[0204] As described above, in the second embodiment, the received signal array 16a has the same data structure in both the normal mode and the fault determination mode. However, in the normal mode, for the direction θ corresponding to the virtual direction, the array stores the levels of the received signals of the virtual reflected waves in the first to sixth virtual directions, which are generated by applying the predetermined filter processing shown in the above equations (1) to (4) by the filter 15 to the received signals in each specific direction indicated by the first center axes C1a to C1f. On the other hand, in the fault determination mode, a value of zero, which is a predetermined fixed intensity, is stored for the direction θ corresponding to the virtual direction.

[0205] Therefore, the ultrasonic sonar device 1 can switch between the normal mode and the fault determination mode simply by switching the received signal stored for the direction θ corresponding to the virtual directions from the first virtual direction to the sixth virtual direction in each mode, while using the received signal array 16a configured with the same data structure in both the normal mode and the fault determination mode.

[0206] Next, in the detection result image generating means 17, in the first embodiment, the conversion tables were a normal conversion table 17a used in the normal mode and a fault judgment conversion table 17b used in the fault judgment mode, whereas in the second embodiment, the detection result image generating means 17 has a conversion table 17c that is used in common in both the normal mode and the fault judgment mode.

[0207] In the second embodiment, the received signal array 16a is configured to have the same data structure in both the normal mode and the failure determination mode, so that the same conversion table 17c can be used in each mode.

[0208] The conversion table 17c used is the same as the failure determination conversion table 17b used in the failure determination mode in the first embodiment. That is, the directions θ associated in the conversion table 17c are 1≦θ<13, and the directions indicated by 12≦θ<13 refer to directions included between the direction θ indicated by "12" (the sixth virtual direction) and the direction θ indicated by "1" (the direction of the first center axis C1b). In this conversion table 17c, only the azimuthal direction θ is associated, and the direction θ indicating the vertical direction (θ=13) is excluded.

[0209] Also, in conversion table 17c, the direction θ and distance R, which are coordinates in the polar coordinate system corresponding to the coordinates (X, Y), are not necessarily natural numbers used as indices in received signal array 16a, but are expressed as decimals, similar to the first embodiment. When the direction θ and distance R, which are coordinates in the polar coordinate system corresponding to the coordinates (X, Y) in conversion table 17c, are expressed as decimals, detection result image generating means 17 identifies the level of the received signal at the position of coordinates (R, θ) by calculating a weighted average, similar to the first embodiment, of the levels of the received signals of four elements of received signal array 16a that are close to the position of coordinates (R, θ) expressed as decimals.

[0210] In the second embodiment, the received signal array 16a is configured such that the azimuth direction θ is alternating between specific directions indicated by the first center axes C1a to C1f and virtual directions (first to sixth virtual directions) set at intermediate positions between adjacent first center axes C1a to C1f, as shown in Fig. 12. In the normal mode, virtual received signals, which are assumed to have transmitted and received virtual beams in the virtual directions, are generated by applying the predetermined filter processing shown in the above-described formulas (1) to (4) to the received signals of the first oscillators 52a to 52f.

[0211] In normal mode, the detection result image generating means 17 performs coordinate conversion using the conversion table 17c based on the levels of the received signals stored in the received signal array 16a, and the intensity of the reflected wave from each pixel of the horizontal detection result image 22 is determined by interpolation using the received signal from one specific direction close to the underwater position indicated by that pixel and the received signal from one virtual direction.The received signal from that virtual direction is then determined using the received signals from specific directions on both sides.In other words, the intensity of the reflected wave from each pixel of the horizontal detection result image 22 is determined by interpolation using the received signals from two specific directions close to the underwater position indicated by that pixel.This interpolation process corresponds to the "predetermined process" of this invention.

[0212] As described above, in the second embodiment, the strength of the reflected wave of each pixel of the horizontal detection result image 22 is determined by interpolation processing using not only the received signals in the specific direction in which the ultrasonic waves TB were actually transmitted and received, but also the received signals in the virtual direction generated by applying a predetermined filter process to the received signals of the first oscillators 52a to 52f as described above. This allows the ultrasonic sonar device 1 to display the horizontal detection result image 22 with improved resolution in the direction in which the specific directions are aligned (i.e., the azimuth direction).

[0213] On the other hand, in the failure determination mode, a virtual beam is transmitted in a virtual direction, and a predetermined fixed intensity (zero in this embodiment) is stored in the received signal array 16a as the level of the received signal indicating the reflection intensity of a virtual reflected wave, which is assumed to be received when the virtual beam is reflected from each position in the virtual direction. In the failure determination mode, the detection result image generation means 17 performs coordinate conversion using the conversion table 17c based on the level of the received signal stored in the received signal array 16a, and the intensity of the reflected wave for each pixel of the horizontal detection result image 22 is determined by interpolation using the received signal from one specific direction close to the underwater position indicated by that pixel and the received signal from one virtual direction with the predetermined fixed intensity. This makes it possible to generate a horizontal detection result image 22 that reflects only the received signals from each specific direction without mixing the received signals from two different specific directions, so that the specific direction in which a failure has occurred can be determined at a glance from the horizontal detection result image 22.

[0214] In the failure determination mode, the intensity of the reflected wave of each pixel of the horizontal detection result image 22 is determined not by an interpolation process using the received signal in one specific direction and the received signal in one virtual direction generated by applying a predetermined filter process to the received signals in two adjacent specific directions, but by disabling the interpolation process and performing an interpolation process using the received signal in one specific direction and the received signal in one virtual direction to which a predetermined fixed intensity is set, which corresponds to one of the "disabling processes" of the present invention, and the means for performing this corresponds to one of the "disabling means" of the present invention.

[0215] Next, a method of performing horizontal detection using the sonar function with the ultrasonic sonar device 1 of this embodiment configured as described above will be described, focusing on the differences from the first embodiment, with reference mainly to Fig. 13, but also to Figs. 1, 2, and 11. Fig. 13 is a flowchart showing horizontal detection result image generation processing executed by the control device 10 according to the second embodiment.

[0216] This horizontal detection result image generation process is executed at the same timing as in the first embodiment. In the second embodiment, when the control device 10 starts the execution of the horizontal detection result image generation process, the same processes of S1 to S3 as in the first embodiment are executed. Then, in the judgment of S3, if the control device 10 judges that the value of the failure judgment mode flag 14a is "0" and that the device is in the normal mode (S3: No), it executes the processes of S4, S11, and S12.

[0217] The process of S4 is the same as the process of S4 in the first embodiment. That is, the control device 10 performs spatial (and temporal) filtering using the filter 15 on the original received signals output from the receiving units 13a to 13g in each of the specific directions of the first center axes C1a to C1f and in the direction of the second center axis C2 (S4). This filtering process of S4 generates a received signal in one specific direction by mixing the original received signals in multiple specific directions, thereby reducing noise and / or improving resolution.

[0218] Next, the control device 10 uses the filter 15 to set a virtual direction at a position midway between the first central axes C1a to C1f adjacent to each of the first central axes C1a to C1f of the first transducers 52a to 52f, which is a specific direction in which the ultrasonic waves TB are transmitted and received, and generates received signals indicating the intensity of virtual reflected waves assumed to be reflected from each position in the water in the virtual direction for a virtual beam transmitted in that virtual direction by applying a predetermined filter processing shown in the above-mentioned equations (1) to (4) to each of the received signals of the first transducers 52a to 52f (S11).

[0219] Then, in the process of S4, the control device 10 stores the levels of the received signals of the reflected waves of the ultrasonic waves TB obtained from the specific directions of the first central axes C1a to C1f, the received signals of the reflected waves of the ultrasonic waves TB obtained from the direction of the second central axis C2, and the received signals of the virtual reflected waves in the first virtual direction to the sixth virtual direction generated by the process of S11, after spatial (and temporal) filtering has been applied by the filter 15, in each element of the received signal array 16a of the storage means 16, which is specified by the polar coordinates (R, θ) of the direction θ, which is an index indicating the direction, and the distance R, which is an index indicating the distance to the underwater position where the reflected wave indicated by the received signal was reflected (S12).

[0220] The control device 10 then uses the conversion table 17c to generate a horizontal detection result image 22 using the detection result image generation means 17 (S13). Specifically, the control device 10 uses the conversion table 17c to identify, for each pixel of the horizontal detection result image 22, the polar coordinates (R, θ) corresponding to the Cartesian coordinates (X, Y) of that pixel. The control device 10 then weighted-averages the levels of the received signals stored in each element of the received signal array 16a near the identified polar coordinates (R, θ) to identify the intensity of the reflected wave from the underwater position corresponding to the pixel indicated by the Cartesian coordinates (X, Y). The control device 10 then generates the horizontal detection result image 22 by assigning a color corresponding to the intensity of the reflected wave from the underwater position corresponding to that pixel, identified for each pixel.

[0221] Then, the control device 10 causes the display control means 18 to display the horizontal detection result image 22 generated in the process of S13 and other images on the display device 21 (S7), and ends the horizontal detection result image generation process.

[0222] As a result, when the ultrasonic sonar device 1 is in normal mode, the display device 21 displays a horizontal detection result image 22 as shown in Fig. 9, as in the first embodiment. However, in the second embodiment, coordinate conversion is performed using the conversion table 17c based on the levels of the received signals stored in the received signal array 16a as shown in Fig. 12(a), and the intensity of the reflected wave from each pixel of the horizontal detection result image 22 is determined by interpolation processing using the received signal from one specific direction close to the underwater position indicated by that pixel and the received signal from one virtual direction.

[0223] As a result, the intensity of the reflected wave of each pixel in the horizontal detection result image 22 is determined by performing interpolation processing using not only the received signal in the specific direction in which the ultrasonic wave TB was actually transmitted and received, but also the received signal in the virtual direction generated by applying a predetermined filter processing to the received signal of each of the first transducers 52a to 52f, so that the resolution in the direction in which the specific directions are lined up (i.e., the azimuth direction) in the horizontal detection result image 22 can be improved compared to the first embodiment.

[0224] On the other hand, if the control device 10 determines in S3 that the value of the failure determination mode flag 14a is "1" and that the device is in failure determination mode (S3: Yes), it executes the same processes of S8 and S9 as in the first embodiment, moves on to the above-mentioned process of S13, and after the process of S7, ends the horizontal detection result image generation process.

[0225] In the failure determination mode, the horizontal detection result image 22 is generated by the process of S13, as in the normal mode. However, in the failure determination mode, as shown in Fig. 12(b), a predetermined fixed intensity of zero is stored in the received signal array 16a as the level of the received signal indicating the reflection intensity of the virtual reflected wave in the virtual direction. By performing coordinate conversion using the conversion table 17c based on the level of the received signal stored in this received signal array 16a, the intensity of the reflected wave of each pixel in the horizontal detection result image 22 is determined by interpolation processing using the received signal from one specific direction close to the underwater position indicated by that pixel and the received signal from one virtual direction to which the predetermined fixed intensity is set.

[0226] This makes it possible to generate a horizontal detection result image 22 as shown in Fig. 10, which reflects only the received signals from each specific direction without mixing the received signals from two different specific directions. Therefore, the specific direction in which the failure is occurring can be determined at a glance from the horizontal detection result image 22.

[0227] The ultrasonic sonar device 1 according to the second embodiment described above provides the following advantageous effects.

[0228] (5) The filter 15 applies the predetermined filter processing shown in the above equations (1) to (4) to the received signal for each specific direction, and generates a received signal indicating the intensity of the reflected wave when it is assumed that a virtual beam is virtually transmitted in a virtual direction set between adjacent specific directions and that a reflected wave virtually reflected from each position in the virtual direction is received.The received signals generated for each specific direction and each virtual direction are then stored in the received signal array 16a of the storage means 16, which is associated with the polar coordinates (R, θ).Then, the detection result image generation means 17 uses the conversion table 17c to identify, for each pixel of the horizontal detection result image 22, the intensity of the reflected wave from the underwater position corresponding to that pixel. That is, the polar coordinates (R, θ) corresponding to the Cartesian coordinates (X, Y) of the pixel to be identified are identified by the conversion table 17c, and the intensity of the reflected wave at that pixel is identified by performing interpolation processing on the identified polar coordinates (R, θ) using the received signal from one specific direction close to that position and the received signal from a virtual direction stored in the received signal array 16a of the storage means 16. As a result, the detection result image generation means 17 can generate the horizontal detection result image 22 by the conversion table 17c using not only the received signal from the specific direction but also the virtual received signal from a virtual direction set between adjacent specific directions, thereby improving the resolution in the direction in which the specific directions are lined up (azimuth direction).

[0229] On the other hand, when the failure determination mode is set by setting the failure determination mode flag 14a of the setting means 14 to "1", a process is executed to store zero as a predetermined fixed intensity for all received signals in the virtual direction stored in the received signal array 16a of the storage means 16. As a result, in the failure determination mode, by simply storing zero as a predetermined fixed intensity for all received signals in the virtual direction stored in the received signal array 16a of the storage means 16, the detection result image generating means 17 uses the same conversion table 17c as in the normal mode to identify, for each pixel of the horizontal detection result image 22, the intensity of the reflected wave from a position corresponding to that pixel, using the received signal in one specific direction close to the position of the polar coordinates (R, θ) stored in the received signal array 16a of the storage means 16 and the received signal in the virtual direction, based on the polar coordinates (R, θ) corresponding to the Cartesian coordinates (X, Y) of the pixel identified by the conversion table 17c. Therefore, in normal mode, a horizontal detection result image 22 with improved resolution in the direction in which specific directions are aligned is generated, while in failure judgment mode, a horizontal detection result image 22 that allows failure judgment at a glance can be generated using the same conversion table 17c as in normal mode without requiring any significant changes to processing from normal mode.

[0230] Additionally, the ultrasonic sonar device 1 according to the second embodiment has the same configuration as the ultrasonic sonar device 1 according to the first embodiment, and therefore has the same effects as the ultrasonic sonar device 1 according to the first embodiment.

[0231] (Variation) Although the present invention has been described above based on the embodiments, it is readily apparent that the present invention is not limited to the above embodiments and that various improvements and modifications are possible within the scope of the present invention. For example, each embodiment may be modified by adding or replacing a part or parts of the configuration of another embodiment, including the modifications described below. Furthermore, the numerical values ​​given in the above embodiments are merely examples, and other numerical values ​​may of course be adopted.

[0232] In each of the above embodiments, the case where the transmitting and receiving unit 50 has, in addition to the first transducers 52a to 52f, a second transducer 53 that transmits and receives ultrasonic waves TB in the vertical direction has been described. However, the present invention is also applicable to an ultrasonic sonar device 1 that uses a transmitting and receiving unit 50 that does not have such a second transducer 53.

[0233] In each of the above embodiments, an ultrasonic sonar device 1 that performs horizontal detection using multiple transducers has been described as an example, but the present invention can also be applied to ultrasonic sonar devices that perform underwater detection using multiple transducers within a predetermined range set underwater, such as vertical cross-sectional detection.

[0234] In each of the above embodiments, we have described a case where underwater detection is performed by reducing the number of first oscillators 52 in the transmitter-receiver unit 50 and simultaneously transmitting and receiving ultrasonic waves TB from the first oscillators 52 over a predetermined range set underwater.However, the present invention is also applicable to ultrasonic sonar devices such as scanning sonars that have a transmitter-receiver unit in which multiple oscillators transmit and receive ultrasonic waves TB each in a different specific direction. [Explanation of symbols]

[0235] 1. Ultrasonic sonar device 10 Control device 11a, 11b transmitting unit 13a~13g receiving unit 14 Setting Method 14a Failure judgment mode flag 15 filters 16 Memory means 16a Received signal array 17 Detection result image generation means 17a Normal conversion table 17b Fault judgment conversion table 17c Conversion Table 22 Horizontal detection result image 31 Operation buttons 50 Transmitting and receiving unit 52a~52f First oscillator 71 Ships C1a~C1f First Central Axis E1a Pointer Characteristics E1b pointing characteristics E1d pointing characteristics E1f pointing characteristics GF Detect the target object R distance SB underwater TB ultrasound θ direction

Claims

1. a wave transmitting / receiving unit including a plurality of transducers that transmit ultrasonic waves in a specific direction underwater and receive reflected waves of the ultrasonic waves reflected from various positions underwater as reflected waves in the specific direction, the transducers being installed such that the specific direction of each transducer is different; a reception signal generating means for generating a reception signal for each of the specific directions based on the reception by each of the transducers of the reflected wave in the specific direction of the transducer; a storage means for storing the reception signals generated by the reception signal generating means for each of the specific directions; a detection result image generating means for generating a detection result image showing the detection result of a detection range set underwater by specifying, for each pixel of the detection result image, the intensity of the reflected wave from the underwater position corresponding to that pixel by performing a predetermined process using at least two of the received signals from the specified directions among the received signals stored in the storage means, and assigning a mode of expressing the specified intensity of the reflected wave to that pixel; and a setting means for setting a failure determination mode for determining a failure; and a disabling means for executing a disabling process for disabling at least the predetermined process when the failure determination mode is set by the setting means, and for controlling the detection result image generating means to identify, for each pixel of the detection result image, the intensity of the reflected wave from a position corresponding to that pixel using a received signal from one of the specific directions close to that position stored in the memory means.

2. the storage means stores the received signal generated by the received signal generation means for each of the specific directions in association with polar coordinates indicated by information corresponding to the direction and information corresponding to the distance to a position where the reflected wave that is the source of the received signal was generated; The detection result image generating means Identifying each pixel of the detection result image by Cartesian coordinates; a conversion table that associates the polar coordinates with the rectangular coordinates of each pixel; For each pixel of the detection result image, the intensity of the reflected wave from an underwater position corresponding to the pixel is identified by performing a predetermined process using the received signals in the two specified directions that are associated with polar coordinates corresponding to the orthogonal coordinates of the pixel identified by the conversion table and stored in the storage means, 2. The ultrasonic sonar device according to claim 1, wherein the invalidating means executes, as the invalidation processing, a process of setting a virtual direction between adjacent specific directions and storing the received signals of the reflected waves from each position in the virtual direction as a predetermined fixed intensity in the storage means, and the detection result image generating means controls to identify, for each pixel of the detection result image, the intensity of the reflected waves from a position corresponding to that pixel using the received signals of one of the specific directions closest to that position stored in the storage means and the received signals of the virtual direction, with respect to polar coordinates corresponding to the Cartesian coordinates of the pixel identified by the conversion table.

3. the reception signal generating means applies a first filter to the reception signal for each of the specific directions to generate a reception signal assuming that an ultrasonic wave is virtually transmitted and received in a virtual direction set between adjacent specific directions; the storage means stores the received signals generated by the received signal generation means for each of the specific directions and each of the virtual directions in association with the polar coordinates; the detection result image generating means specifies, for each pixel of the detection result image, the intensity of the reflected wave from an underwater position corresponding to the pixel by performing the predetermined processing using a received signal in the specific direction close to the position and a received signal in the virtual direction that are associated with polar coordinates corresponding to the orthogonal coordinates of the pixel specified by the conversion table and stored in the storage means, 3. The ultrasonic sonar device according to claim 2, wherein the invalidating means executes, as the invalidating process, a process of storing a predetermined fixed intensity for all the received signals in the virtual direction stored in the storage means.

4. the received signal generating means applies a second filter to an original received signal obtained by each of the transducers receiving the reflected wave in the specific direction of the transducer to generate a received signal for each of the specific directions, 2. The ultrasonic sonar device according to claim 1, wherein the nullifying means performs the nullifying process by not applying a second filter to the original received signal generated by the received signal generating means.

5. 2. The ultrasonic sonar device according to claim 1, wherein each of the plurality of transducers provided in the transmitting and receiving unit is fixed so that its central axis is in the specific direction, and has a predetermined directional characteristic so as to include the central axis of at least an adjacent transducer.

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