Ultrasonic Sonar Device

Abstract

The ultrasonic sonar device 1 comprises first transducers 52a-52f and a second transducer 53 capable of transmitting ultrasonic waves over a predetermined range underwater and receiving reflected waves of the ultrasonic waves reflected from each position underwater for each predetermined direction, receiving units 13a-13g and a filter 14 which generate received signals for each predetermined direction based on the reflected waves received by each transducer, a first detection result image generating means 15 which generates a first detection result image showing the latest detection result over the predetermined range based on the generated received signals for each predetermined direction, and a second detection result image generating means 16 which generates a second detection result image in which the detection results of the first range are arranged in chronological order based on the received signals of a predetermined direction included in a first range of the predetermined range.

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] There is known an ultrasonic sonar device that detects a detection target such as a school of fish over a predetermined range underwater by transmitting and receiving ultrasonic waves. A general fish detection device detects a detection target in a vertical direction from a ship, whereas an ultrasonic sonar device can detect a detection target present around a ship by horizontal detection, vertical cross-sectional detection, etc. Known examples of ultrasonic sonar devices include PPI sonar (searchlight sonar) and scanning sonar.

[0003] PPI sonar emits (transmits) a thin beam of ultrasonic waves and has a transducer that can rotate or pivot to receive the reflected waves from the object to be detected, and detects the underwater area around the ship while changing the direction of ultrasonic emission (for example, Patent Document 1). Because the transducer has a simple structure, it can be constructed at low cost, but it takes time to complete one detection over a specified range.

[0004] Scanning sonar forms multiple minute transducers in an array on the surface of a cylinder, sphere, etc., and simultaneously transmits ultrasonic waves from each transducer and receives the reflected waves to perform a single underwater detection around a ship (for example, Patent Document 2). While a single detection over a given range can be performed in a short time, the transducer array is complex and the transmission and reception circuitry for transmitting and receiving ultrasonic waves in each transducer is large, making it expensive. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-066208 A [Patent Document 2] JP 2019-200204 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the case of horizontal detection, an ultrasonic sonar device displays the detection results in each azimuth direction in a circular detection result image, and in the case of vertical cross-sectional detection, the detection results in each elevation angle direction are displayed in a sector-shaped (or triangular) detection result image. In the case of PPI sonar, each time ultrasonic waves are transmitted in a direction and their reflected waves are received, the detection results in that direction are overwritten on the detection image. In other words, in PPI sonar, the latest detection results in each direction are shown on the detection image. Also, in the case of scanning sonar, each time ultrasonic waves are transmitted in all directions at once and their reflected waves are received, the detection results in all directions are overwritten on the detection image.

[0007] In this way, ultrasonic sonar devices often miss fish shadows because they only contain detection results for at least one point in time for each direction. Conventionally, to solve this problem, vertical detection has been performed in addition to general fish detection, which keeps a history of detection results. However, general fish detection and sonar (PPI sonar and scanning sonar) detect different locations, so the above problem has not been fundamentally solved.

[0008] The present invention has been made to solve such problems, and has an object to provide an ultrasonic sonar device that can reduce the risk of overlooking a detection target. [Means for solving the problem]

[0009] In order to achieve this object, a first aspect of the present invention is an ultrasonic sonar device comprising: a transmit / receive unit capable of transmitting ultrasonic waves over a predetermined range underwater and receiving reflected waves of the ultrasonic waves reflected from each position underwater for each predetermined direction; a received signal generating means for generating a received signal for each of the predetermined directions based on the reflected waves received by the transmit / receive unit; a first detection result image generating means for generating a first detection result image showing the latest detection result over the predetermined range based on the received signals for each of the predetermined directions generated by the received signal generating means; and a second detection result image generating means for generating a second detection result image in which the detection results of the first range are arranged in chronological order based on the received signals for the predetermined direction included in a first range of the predetermined range.

[0010] A second aspect of the present invention is an ultrasonic sonar device according to the first aspect, wherein when the first range includes a plurality of the specified directions, the second detection result image generating means synthesizes the received signals for each of the plurality of the specified directions and generates the second detection result image based on the synthesized received signals.

[0011] A third aspect of the present invention is an ultrasonic sonar device according to the second aspect, wherein the combination of the received signals is performed by selecting, for each depth, the maximum level among the levels of the multiple received signals to be combined.

[0012] A fourth aspect of the present invention is the ultrasonic sonar device according to any one of the first to third aspects, wherein the first range is the same range as the predetermined range.

[0013] A fifth aspect of the present invention is an ultrasonic sonar device according to any one of the first to fourth aspects, comprising a third detection result image generating means for generating a third detection result image in which the detection results of the second range are arranged in chronological order based on the received signal in the specified direction included in a second range different from the first range among the specified range.

[0014] A sixth aspect of the present invention is an ultrasonic sonar device according to the fifth aspect, wherein the first range covers the starboard side of a ship on which the transmitting and receiving unit is provided, and the second range covers the port side of the ship.

[0015] A seventh aspect of the present invention is an ultrasonic sonar device according to the fifth or sixth aspect, wherein the first range covers the front side of the ship on which the transmitting and receiving unit is provided, and the second range covers the rear side of the ship.

[0016] An eighth aspect of the present invention is an ultrasonic sonar device according to any one of the first to seventh aspects, wherein the transmitting and receiving unit comprises a plurality of first transducers having a predetermined directional characteristic, each of the plurality of first transducers being fixed so that its central axis is in the predetermined direction and is positioned at a predetermined angle relative to the vertical direction when the transmitting and receiving unit is attached to the ship, and having the predetermined directional characteristic so as to include at least the central axes of adjacent first transducers and the vertical direction.

[0017] A ninth aspect of the present invention is an ultrasonic sonar device according to the eighth aspect, wherein the transmitting and receiving unit further has a second transducer fixed so that its central axis is positioned in the vertical direction when mounted on a ship.

[0018] A tenth aspect of the present invention is an ultrasonic sonar device according to the eighth or ninth aspect, comprising a transmission unit which distributes a drive signal for transmitting ultrasonic waves from the plurality of first transducers of the wave transmitting and receiving unit to the plurality of first transducers via diodes to simultaneously drive the plurality of first transducers, and a transmission unit which distributes a drive signal for transmitting ultrasonic waves from the plurality of first transducers of the wave transmitting and receiving unit to the plurality of first transducers via diodes to simultaneously drive the plurality of first transducers, Setting and a receiving unit configured to receive the reflected wave and output a signal from the corresponding first oscillator and to perform predetermined processing on the signal. Effect of the Invention

[0019] According to the ultrasonic sonar device according to the first aspect of the present invention, ultrasonic waves are transmitted by the wave transmitting / receiving unit over a predetermined range in water. Then, the reflected waves of the ultrasonic waves reflected from each position in water for each predetermined direction are received by the wave transmitting / receiving unit. Based on the reflected waves received by the wave transmitting / receiving unit, a reception signal is generated for each predetermined direction by the reception signal generating means. Based on the generated reception signals for each predetermined direction, a first detection result image showing the latest detection result over the predetermined range is generated by the first detection result image generating means. From this first detection result image, it is possible to determine the presence or absence of a detection target in the predetermined range and the direction in which the detection target exists. On the other hand, based on the reception signals for a predetermined direction included in the first range of the predetermined range, a second detection result image in which the detection results of the first range are arranged in chronological order is generated by the second detection result image generating means. As a result, the history of the detection results of the detection target that existed in the first range remains in the second detection result image. Therefore, there is an effect that it is possible to suppress overlooking of the detection target.

[0020] The ultrasonic sonar device according to the second aspect has the following effect in addition to the effect of the ultrasonic sonar device according to the first aspect. That is, when the first range includes a plurality of predetermined directions, the reception signals for each of the plurality of predetermined directions are synthesized, and the second detection result image is generated by the second detection result image generating means based on the synthesized reception signals. Therefore, the detection results of the detection target based on the transmission and reception of ultrasonic waves performed for each of the plurality of predetermined directions included in the first range are included in the second detection result image without omission, and further, the history of the detection results remains in the second detection result image, so that there is an effect that the overlooking of the detection target can be more reliably suppressed.

[0021] The ultrasonic sonar device according to the third aspect has the following effect in addition to the effect of the ultrasonic sonar device according to the second aspect. That is, the synthesis of received signals performed by the second detection result image generating means is performed by selecting the maximum level from the levels of the multiple received signals to be synthesized for each depth. This makes it possible to reliably display reflected waves with high reflection intensity that are likely to be the detection target in the second detection result image. This has the effect of more reliably preventing the detection target from being overlooked.

[0022] The ultrasonic sonar device according to the fourth aspect has the following effect in addition to the effect of the ultrasonic sonar device according to any one of the first to third aspects. That is, the first range, which is the detection range of the detection result shown in the second detection result image, is the same as the predetermined range, which is the detection range of the detection result shown in the first detection result image. This allows the history of the detection results of the detection targets that existed in the detection range (i.e., the predetermined range) of the detection result shown in the first detection result image to remain in the second detection result image, thereby having the effect of suppressing overlooking the detection targets over the predetermined range.

[0023] According to the ultrasonic sonar device of the fifth aspect, in addition to the effects of the ultrasonic sonar device of any one of the first to fourth aspects, the following effect is achieved. That is, a third detection result image in which the detection results of the second range are arranged in chronological order is generated by the third detection result image generating means based on a received signal in a predetermined direction included in a second range different from the first range among the predetermined ranges. As a result, not only the history of the detection results of the detection target that existed in the first range remains in the second detection result image, but also the history of the detection results of the detection target that existed in the second range remains in the third detection result image. Therefore, there is an effect that it is possible to easily grasp in which range the detection target existed, including in the past, while suppressing overlooking of the detection target.

[0024] The ultrasonic sonar device according to the sixth aspect has the following effect in addition to the effect of the ultrasonic sonar device according to the fifth aspect. That is, the second detection result image retains the history of detection results of detection objects that existed in the range on the starboard side of the ship on which the wave transmitting and receiving unit is provided as the first range, and the third detection result image retains the history of detection results of detection objects that existed in the range on the port side of the ship as the second range. This has the effect of making it easy to know whether the detection object was on the starboard side or the port side of the ship, including in the past.

[0025] The ultrasonic sonar device according to the seventh aspect has the following effect in addition to the effect of the ultrasonic sonar device according to the fifth or sixth aspect. That is, the second detection result image retains the history of detection results of detection objects that existed in the range on the front side of the ship where the wave transmitting / receiving unit is provided as the first range, and the third detection result image retains the history of detection results of detection objects that existed in the range on the rear side of the ship as the second range. This has the effect of making it easy to know whether a detection object has existed on the front side or rear side of the ship, including in the past.

[0026] According to the ultrasonic sonar device of the eighth aspect, in addition to the effects of the ultrasonic sonar device of any one of the first to seventh aspects, the following effects are achieved. That is, a plurality of first transducers are fixed to the transceiver unit so that their central axes are in a predetermined direction and are located at a predetermined angle with respect to the vertical direction when the transceiver unit is attached to the ship. Each first transducer has a predetermined directional characteristic that includes at least the central axis of the adjacent first transducer and the vertical direction. This makes it possible to simultaneously transmit ultrasonic waves over a predetermined range with a small number of first transducers and to detect the detection target by receiving the reflected waves. Therefore, there is an effect that an ultrasonic sonar device capable of high-speed detection can be constructed at low cost.

[0027] The ultrasonic sonar device according to the ninth aspect has the following effect in addition to the effect of the ultrasonic sonar device according to the eighth aspect. That is, in addition to the first transducer, the wave transmitting and receiving unit is provided with a second transducer fixed so that its central axis is positioned in the vertical direction when the wave transmitting and receiving unit is attached to the ship. This has the effect of enabling detection of a detection target in the vertical direction with high accuracy.

[0028] According to the ultrasonic sonar device of the tenth aspect, in addition to the effects of the ultrasonic sonar device of the eighth or ninth aspect, the following effects are achieved. That is, a driving signal for transmitting ultrasonic waves from the multiple first transducers of the wave transmitting and receiving unit is distributed to the multiple first transducers via diodes by the transmitting unit, and the multiple first transducers are driven simultaneously. Also, a receiving unit provided corresponding to each of the multiple first transducers of the wave transmitting and receiving unit takes in a signal output by the corresponding first transducer receiving a reflected wave, and performs a predetermined process. As a result, while driving the multiple first transducers by one transmitting unit, the signals output from each first transducer can be processed individually, which has the effect of significantly reducing costs and size. [Brief description of the drawings]

[0029] [Figure 1] 1 is a schematic diagram showing a configuration of an ultrasonic sonar device according to an embodiment of the present invention; [Diagram 2] 2 is a schematic side view showing the state in which the ultrasonic sonar device is mounted on a ship and used for underwater detection. FIG. [Diagram 3] FIG. 2A is a schematic cross-sectional view showing a wave transmitting and receiving unit of the ultrasonic sonar device, and FIG. 2B is a schematic perspective view showing an arrangement of a plurality of first transducers and a second transducer that constitute 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 ultrasound transmitted from the first transducers, and (d) is a diagram showing the directional characteristics of ultrasound transmitted from the first transducers when viewed from the front side of the ship. [Diagram 5] FIG. 2 is a block diagram showing the electrical configuration of the ultrasonic sonar device. [Figure 6] 2 is a diagram showing an example of a display screen displayed on a display device of the ultrasonic sonar device. FIG. [Figure 7] 13 is a flowchart showing a second detection result image generating process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, the embodiments for carrying out the present invention will be described with reference to the accompanying drawings. Note that each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement positions and connection forms of the components 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 described in the independent claims showing the highest concept of the present invention will be described as optional components. In addition, in each drawing, substantially the same configuration is given the same reference numeral, and duplicated explanations will be omitted or simplified.

[0031] First, an ultrasonic sonar device 1 according to an embodiment of the present invention will be described with reference to Figures 1 and 2. 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 ship 71 equipped with the ultrasonic sonar device 1 performing underwater detection.

[0032] 1 and 2, the ultrasonic sonar device 1 is mounted on a ship 71 and has at least a sonar function of horizontally detecting detection targets GF, such as schools of fish, over a predetermined range around the ship 71 in the waters of the sea, lake, river, or the like on which the ship 71 floats. Horizontal detection is a predetermined range in all directions as seen from the ship 71, and detects detection targets GF included in the predetermined range. The ultrasonic sonar device 1 may have a sonar function of performing vertical cross-sectional detection in addition to horizontal detection, and may also have a fish detection function of detecting detection targets GF present in the vertical direction directly below the ship 71 and displaying the detection results in a chronological order.

[0033] The ultrasonic sonar device 1 includes a main body 5, an operation button 31 provided on the main body 5, a display device 21 formed integrally with the main body 5, a wave transmission / reception unit 50 that transmits and receives ultrasonic waves TB for detecting a detection target GF, and a lifting device 41 that raises and lowers the wave transmission / reception unit 50. The main body 5, the operation button 31, and the display device 21 are disposed in the wheelhouse of the ship 71, while the wave transmission / reception unit 50 and the lifting device 41 are disposed in the bottom of the ship 71. The wave transmission / reception 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.

[0034] 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 on / off the power of the ultrasonic sonar device 1, set the brightness of the image displayed by the display device 21, issue an instruction to start / end the execution of horizontal detection by the sonar function, set the detection range indicated by the second detection result image 23 (hereinafter referred to as the "first range") and the detection range indicated by the third detection result image 24 (hereinafter referred to as the "second detection group"), which will be described later, and the like.

[0035] 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 included in the predetermined cone-shaped range, the bottom of the sea or lake (hereinafter collectively referred to as the "bottom SB"). The detailed configuration of the wave transmitting and receiving unit 50 will be described later with reference to FIGS. 3 and 4.

[0036] The display device 21 displays the detection result based on the reception signal generated by receiving units 13a-13g (described later) and a filter 14 (see FIG. 5) when the transmitting / receiving unit 50 receives the reflected wave of the ultrasonic wave TB, and is configured, for example, by a liquid crystal display or an organic EL (Electro-Luminescence) display. When the ultrasonic sonar device 1 executes horizontal detection using the search function, a first detection result image 22, a second detection result image 23, and a third detection result image 24 are displayed as detection result images on the display device 21. Details of these detection result images will be described later with reference to FIG. 6.

[0037] Next, a 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 an arrangement of a plurality of first transducers 52 (52a to 52f) and a second transducer 53 that constitute the wave transmitting and receiving unit 50.

[0038] 4(a) is a diagram showing the first central axes C1a-C1f of the first transducers 52a-52f when viewed vertically from above the ship 71, and FIG. 4(b) is a diagram showing the first central axes C1a-C1f of the first transducers 52a-52f when viewed horizontally from the front side of the ship 71. FIG. 4(c) is a diagram showing the directional characteristics of ultrasonic waves TB transmitted from adjacent first transducers 52a, 52b, and 52f, and FIG. 4(d) is a diagram showing the directional characteristics of ultrasonic waves TB transmitted from the first transducers 52a and 52d when viewed from the front side of the ship 71.

[0039] As shown in FIG. 3, the wave transmitting / receiving unit 50 has a structure in which a plurality of (six in the example shown in FIG. 3) first transducers 52 (first transducer 52a, first transducer 52b, first transducer 52c, first transducer 52d, first transducer 52e, first transducer 52f) that transmit ultrasonic waves TB in a predetermined direction and receive the reflected waves are housed in a case 51 and molded. Each of the first transducers 52 is a disk-shaped structure having the same size and shape. Similarly to the first transducer 52, the second transducer 53 also has a disk-shaped shape. However, the size of the second transducer 53 is determined according to the required characteristics. That is, the second transducer 53 may be the same size as the first transducer 52, or may be a different size from the first transducer 52.

[0040] Each of the first transducer 52 and the second transducer 53 includes a base material 54 and a piezoelectric element 55. The base material 54 is a disk-shaped resin plate material that also serves as an acoustic matching layer, and is made of, for example, glass epoxy.

[0041] The piezoelectric element 55 is a plate-like object made of piezoelectric ceramics, 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 base material 54 via an adhesive layer (not shown), and a rear electrode (not shown) formed on its rear surface opposite the front surface. Lead wires are electrically connected to the front electrode and the rear electrode, respectively.

[0042] When a driving voltage is applied from a transmitting unit 11a or a transmitting unit 11b (see FIG. 5) described later via a front electrode and a back electrode, the piezoelectric element 55 deforms in the thickness direction to vibrate the base material 54. This vibration of the base material 54 causes each of the first oscillator 52 and the second oscillator 53 to generate an ultrasonic wave TB.

[0043] In addition, when the reflected wave of the ultrasonic wave TB vibrates the substrate 54 of each of the first transducer 52 and the second transducer 53, the vibration deforms the piezoelectric element 55, generating a voltage between the front electrode and the back electrode. The first transducers 52a-52f and the second transducer 53 output the voltage generated between the front electrode and the back electrode to the corresponding receiving units 13a-13g, which will be described later, to generate reception signals corresponding to the reflected wave received by each of the first transducers 52a-52f and the second transducer 53.

[0044] The case 51 has an opening at one end, and a plurality of first transducers 52 and second transducers 53 are housed in the case 51. The second transducer 53 is disposed at the center of the case 51. Six first transducers 52 are disposed around the second transducer 53 in the order of the first transducer 52a, the first transducer 52b, the first transducer 52c, the first transducer 52d, the first transducer 52e, and the first transducer 52f, in a counterclockwise direction as viewed from the front surface side of the base material 54. The acoustic radiation surface formed on the front surface of the base material 54 of each of the first transducers 52 and the acoustic radiation surface formed on the front surface of the base material 54 of the second transducer 53 are all located on one imaginary spherical surface.

[0045] In this embodiment, the number of first transducers 52 is six, but the number of first transducers 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 transducers 52 is large, the configuration of the ultrasonic sonar device 1 becomes complicated, large, and expensive, so the number of first transducers 52 is preferably ten or less, and more preferably eight or less.

[0046] Here, the direction of the first central axis C1a (which can also be said to be the direction of the normal vector of the first oscillator 52a) that is the central axis perpendicular to the center of the front surface (sound radiation surface) of the base material 54 can be understood as the sound radiation direction of the first oscillator 52a. Similarly to the first oscillator 52a, the first oscillator 52b is defined as the first central axis C1b, the first oscillator 52c is defined as the first central axis C1c, the first oscillator 52d is defined as the first central axis C1d, the first oscillator 52e is defined as the first central axis C1e, and the first oscillator 52f is defined as the first central axis C1f. Each of the first central axes C1b to C1f can be understood as the sound radiation direction of the corresponding first oscillator 52b to 52f.

[0047] Furthermore, the direction of the second central axis C2, which is a central axis perpendicular to the center of the front surface (acoustic radiation surface) of the base material 54 (which can also be said to be the direction of the normal vector of the second oscillator 53), can be understood to be the acoustic radiation direction of the second oscillator 53.

[0048] That is, the first central axes C1a to C1f of the first transducers 52a to 52f and the second central axis C2 of the second transducer 53 are in a predetermined direction for transmitting ultrasonic waves TB to a predetermined range, which is the detection range of the detection target GF, and for receiving the reflected waves.

[0049] Here, the wave transmitting / receiving unit 50 is attached to the ship 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 (irradiates) ultrasonic waves TB in the vertical direction directly below the ship 71. Due to the presence of this second transducer 53, the ultrasonic sonar device 1 can detect the detection target GF in the vertical direction with high accuracy. Note that it is preferable that the directional characteristics of the ultrasonic waves TB transmitted from the second transducer 53 are a narrow beam with a small directional angle. This can further increase the accuracy of detection of the detection target GF in the vertical direction.

[0050] On the other hand, in the wave transmitting and receiving unit 50, the first transducers 52a-52f are arranged with the sound emitting surface of each of the first transducers 52a-52f inclined such that the first central axes C1a-C1f form a predetermined angle θ 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 shown in Fig. 3. As a result, the sound emitting direction of each of the first transducers 52a-52f faces in a direction different from the vertical direction directly below the ship 71, as shown in Fig. 4(b).

[0051] In this embodiment, the first transducers 52a-52f are inclined with their acoustic radiation surfaces facing inward (toward the side where the second transducer 53 is located) (see FIG. 3). In this case, it is preferable that each of the first central axes C1a-C1f forms a predetermined angle θ with respect to the second central axis C2, the angle being selected from a range of 20° or more and 50° or less. In this embodiment, the predetermined angle θ is 30°. As shown in FIG. 3(a), each of the first central axes C1a-C1f and the second central axis C2 are converged at one point.

[0052] 4(a), when the wave transmitting / receiving unit 50 is attached to the ship 71 and viewed vertically from above the ship 71, the first central axes C1a to C1f of the first transducers 52a to 52f are disposed at equal intervals in the azimuth direction so that adjacent first central axes C1a to C1f form the same angle δ. 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°).

[0053] As a result, the transmitting and receiving unit 50 can transmit ultrasonic waves TB simultaneously in each of the predetermined directions indicated by the first central axes C1a to C1f using at least the first transducers 52a to 52f over a predetermined range set in all directions of the ship 71, and can also receive reflected waves in each of the predetermined directions.

[0054] 4(a) and 4(b), the wave transmitting / receiving unit 50 is attached to the ship 71 so that, when the ship 71 is viewed vertically from above, the first central axis C1a faces the rightward direction with respect to the longitudinal direction of the ship 71, and the first central axes C1b to C1f are arranged counterclockwise from the first central axis C1a at intervals of an angle δ. In addition, in the present 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 the first transducers 52a to 52f can transmit ultrasonic waves TB simultaneously in each of the predetermined directions 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.

[0055] 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 characteristics of the ultrasonic waves TB transmitted from the first transducer 52a are 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.

[0056] On the other hand, the directional characteristics of the ultrasonic waves TB transmitted from the first transducer 52b and the directional characteristics of the ultrasonic waves TB transmitted from the first transducer 52f are both set to include the first central axis C1a of the first transducer 52a. Although not shown in the figure, the directional characteristics of the ultrasonic waves TB transmitted from the first transducer 52b are also set to include the first central axis C1c of the first transducer 52c adjacent to the first transducer 52a on the opposite side, and the directional characteristics of the ultrasonic waves TB transmitted from the first transducer 52f are also set to include the first central axis C1e of the first transducer 52e adjacent to the first transducer 52a on the opposite side.

[0057] Furthermore, the directional characteristics of the ultrasonic waves TB transmitted from each of the first transducers 52a to 52f are set so as to include the vertical direction when the wave transmitting and receiving unit 50 is attached to the ship 71, as shown in FIG. 4(d).

[0058] As described above, the ultrasonic waves TB transmitted from each of the first transducers 52a-52f include the first central axes C1a-C1f of the adjacent first transducers 52, and the directivity is set so as 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-52f, the transducer unit 50 irradiates ultrasonic waves TB from each of the first transducers 52a-52f in the direction of the respective first central axes C1a-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.

[0059] Furthermore, the directions of the first central axes C1a-C1f of the first transducers 52a-52f and the directional characteristics of the ultrasonic waves TB radiated from the first transducers 52a-52f are fixed so that the ultrasonic waves TB are radiated over a predetermined range from the wave transmitting / receiving unit 50. This makes it possible to eliminate the need for circuits for controlling the directions of the first central axes C1a-C1f of the first transducers 52a-52f and circuits for controlling the directional characteristics of the ultrasonic waves TB radiated from the first transducers 52a-52f.

[0060] The wave transmitting / receiving unit 50 can receive the reflected waves of the ultrasonic waves TB reflected from the detection target GF present within the predetermined range by the first transducers 52a-52f corresponding to each of the first central axes C1a-C1f, which are predetermined directions. As described above, the ultrasonic sonar device 1 can be constructed to perform high-speed detection in a small size at low cost.

[0061] 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 packed together so that the first central axes C1a-C1f and the second central axis C2 are respectively in the above-mentioned directions, and is fixed by a filler. As the filler, a waterproof resin material (e.g., urethane resin, etc.) is used, which has a lower specific acoustic impedance than the base material 54 that is the acoustic matching layer of the first transducer 52 and the second transducer 53. The filler is filled so that the outer surface is flush with the opening of the case 51, thereby closing the opening of the case 51.

[0062] 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, 11b, diodes 12a-12g, receiving units 13a-13g, a filter 14, a first detection result image generating means 15, a second detection result image generating means 16, a third detection result image generating means 17, and a display control means 18.

[0063] Each of the transmitting units 11a, 11b, the receiving units 13a to 13g, the filter 14, the first detection result image generating means 15, the second detection result image generating means 16, the third detection result image generating means 17, and the display control means 18 may be configured in hardware, may be realized by software, or may be realized by a combination of hardware and software.

[0064] Although not shown in the figure, 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.

[0065] Of the transmitting units 11a, 11b, the receiving units 13a to 13g, the filter 14, the first detection result image generating means 15, the second detection result image generating means 16, the third detection result image generating means 17, and the display control means 18, the parts that are realized by software or by a combination of hardware and software are realized by the CPU executing a program.

[0066] The transmission unit 11a generates one drive signal for transmitting ultrasonic waves TB from the first transducers 52a to 52f based on an instruction from the CPU. The output of 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 is input to the first transducer 52a via the diode 12a, one is input to the first transducer 52b via the diode 12b, one is input to the first transducer 52c via the diode 12c, one is input to the first transducer 52d via the diode 12d, one is input to the first transducer 52e via the diode 12e, and one is input to the first transducer 52f via the diode 12f.

[0067] 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.

[0068] 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 timing. Therefore, ultrasonic waves TB can be transmitted uniformly in a predetermined direction (i.e., the direction of the first central axes C1a-C1f) included in a predetermined range set in all directions with respect to the ship 71, so that the detection sensitivity can be made uniform in all predetermined directions.

[0069] Furthermore, since one transmission unit 11a is provided for the plurality of first transducers 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 transducers 52a to 52f.

[0070] In addition, the diodes 12a-12f are provided between the transmission unit 11a and each of the first transducers 52a-52f, downstream of the branching point where the drive signal output from the transmission unit 11a branches toward each of the first transducers 52a-52f, so that the signal (voltage) output by each of the first transducers 52a-52f receiving the reflected wave of the ultrasonic wave TB can be prevented from flowing back to the transmission unit 11a or from entering the signal line of the other first transducers 52a-52f via the branching point, causing interference. Therefore, even if one transmission unit 11a is provided for the multiple (six) first transducers 52a-52f, the independence of the signals (voltages) output from each of the first transducers 52a-52f can be ensured.

[0071] The transmission unit 11b generates a drive signal for transmitting the ultrasonic wave TB from the second transducer 53 based on an instruction from the CPU. The output of the drive signal generated by the transmission unit 11b is input to the second transducer 53 via a diode 12g. The diode 12g is an element for passing the drive signal generated by the transmission unit 11b and inputting it to the second transducer 53, and for blocking a signal (voltage) generated by receiving a reflected wave at the second transducer 53 so as not to be transmitted to the transmission unit 11b. This diode 12g can prevent the signal (voltage) output by the second transducer 53 by receiving a reflected wave of the ultrasonic wave TB from flowing back to the transmission unit 11b.

[0072] 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 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 when performing horizontal detection as a sonar function.

[0073] In this embodiment, the transmission unit 11a corresponding to the first transducers 52a-52f and the transmission unit 11b corresponding to the second transducer 53 are provided separately, but if the specifications of the ultrasonic sonar device 1 are such that the transmission of ultrasonic waves TB from the second transducer 53 can always be performed at the same timing as the first transducers 52a-52f, then only one transmission unit 11a may be provided for the first transducers 52a-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 further significantly reduced in cost and size.

[0074] The receiving units 13a to 13g are provided for each of the multiple (six) first transducers 52a to 52f and second transducers 53, and when the corresponding first transducers 52a to 52f and second transducers 53 receive the reflected waves of the ultrasonic waves TB, they capture a signal (voltage) output according to the intensity of the reflected waves, and perform a predetermined processing on the captured signal.

[0075] That is, the receiving unit 13a is connected to the first oscillator 52a, and performs a predetermined process on a signal (voltage) outputted according to the intensity of the reflected wave received by the first oscillator 52a. The receiving unit 13b is connected to the first oscillator 52b, the receiving unit 13c is connected to the first oscillator 52c, the receiving unit 13d is connected to the first oscillator 52d, the receiving unit 13e is connected to the first oscillator 52e, the receiving unit 13f is connected to the first oscillator 52f, and the receiving unit 13g is connected to the second oscillator 53. Each of the receiving units 13b to 13g also performs a predetermined process on a signal (voltage) outputted according to the intensity of the reflected wave received by the connected first oscillator 52b to 52f or the second oscillator 53.

[0076] Each of the receiving units 13a to 13g has an amplifier circuit and an analog-to-digital conversion circuit, and as a predetermined process, the received signal (voltage) is amplified by the amplifier circuit and then converted into a digital signal (digital value) by the analog-to-digital conversion circuit (AD conversion circuit).

[0077] Then, the receiving unit 13a outputs a digital signal obtained by an AD conversion circuit as a reception signal received by the first transducer 52a (a reception signal of a reflected wave of the ultrasonic wave TB) to the filter 14. Similarly, the receiving unit 13b outputs a digital signal obtained by each AD conversion circuit as a reception signal of the first transducer 52b, the receiving unit 13c outputs a digital signal obtained by the first transducer 52c, the receiving unit 13d outputs a digital signal obtained by the first transducer 52d, the receiving unit 13e outputs a digital signal obtained by the first transducer 52e, the receiving unit 13f outputs a digital signal obtained by the first transducer 52f, and the receiving unit 13g outputs a digital signal obtained by the second transducer 53 to the filter 14.

[0078] As described above, one transmitting unit 11a is provided for the multiple (six) first transducers 52a-52f to reduce costs and size, whereas receiving units 13a-13f are provided for each of the multiple first transducers 52a-52f, making it possible to perform predetermined processing on each signal (voltage) while maintaining the independence of the signal (voltage) output from each of the first transducers 52a-52f. Meanwhile, since the ultrasonic sonar device 1 is configured with fewer transducers than conventional scanning sonars, even if receiving units 13a-13f are provided for each of the first transducers 52a-52f, the overall receiving unit can be made smaller and costs can be reduced compared to conventional scanning sonars.

[0079] 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 transducers 52a to 52f and second transducer 53. The original reception signals are reception signals before filtering by the filter 14, which will be described next.

[0080] The filter 14 performs a predetermined filtering process on the reception signals (original reception signals) output from the reception units 13a to 13g to each of the first transducers 52a to 52f and the second transducer 53. The predetermined filtering process includes spatial filtering and may also include temporal filtering.

[0081] As the spatial filtering process, filtering is performed in the azimuth direction and the distance direction on the original reception signal of each of the first transducers 52a to 52f that receives the reflected wave of the ultrasonic wave TB for each predetermined direction, for the purpose of reducing noise and / or improving the resolution, etc. The spatial filtering process also includes filtering in the distance direction on the original reception 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.

[0082] Here, the azimuth direction is the direction in which the first central axes C1a to C1f of the first transducer 52a to first transducer 52f, i.e., the respective acoustic emission directions, are aligned, in other words, the circumferential direction centered on the ship 71. Moreover, the distance direction is the direction in which ultrasonic waves TB are transmitted from the first central axes C1a to C1f of the first transducer 52a to first transducer 52f and the second central axis C2 of the second transducer 53, i.e., the respective acoustic emission directions themselves.

[0083] Furthermore, when performing horizontal detection using the sonar function, the ultrasonic sonar device 1 performs detection using a small number of transducers, the first transducers 52a to 52f (six in this embodiment), and therefore the azimuth resolution is significantly reduced. Therefore, in the horizontal detection, the filter 14 sets a virtual direction at a midpoint between the first central axes C1a to C1f adjacent to the first central axes C1a to C1f of the first transducers 52a to 52f, which are the predetermined direction in which the ultrasonic wave TB is transmitted and received, and generates a reception signal, which is assumed to have been virtually transmitted and received in the virtual direction, from the reception signals of the first transducers 52a to 52f.

[0084] By generating virtual reception signals in virtual directions, the number of directions in which ultrasonic waves TB are transmitted and received, including the virtual directions, can be doubled (12 directions in this embodiment) as the actual number of first transducers 52, thereby improving the azimuth resolution.

[0085] On the other hand, the temporal filtering process is a process in which a received signal indicating the intensity of a reflected wave reflected from a certain depth in a certain direction is filtered together with at least one received signal received earlier in time from the same direction and the same depth and / or at least one received signal received later in time. This temporal filtering process allows detection result images (first detection result image 22, second detection result image 23, and third detection result image 24) to be described later and displayed on the display device 21 to be changed smoothly over time, allowing the user to visually recognize the detection result images without any sense of discomfort.

[0086] The filter 14 performs a predetermined filter process on the original reception signals of each of the first transducer 52a to 52f and the second transducer 53, and outputs the values ​​obtained by the filter process as the reception signals of each of the first transducer 52a to 52f and the second transducer 53, and also outputs the virtual reception signals, when a virtual reception signal is generated for a virtual direction, to a first detection result image generating means 15, a second detection result image generating means 16, and a third detection result image generating means 17, which will be described next. The receiving units 13a to 13g and the filter 14 correspond to the reception signal generating means of the present invention.

[0087] The first detection result image generating means 15 generates a first detection result image 22 which is one of the detection result images to be displayed on the display device 21 when the ultrasonic sonar device 1 performs horizontal detection as a sonar function. The second detection result image generating means 16 generates a second detection result image 23 which is one of the detection result images to be displayed on the display device 21 together with the first detection result image 22 when the horizontal detection is performed. The third detection result image generating means 17 generates a third detection result image 24 which is one of the detection result images to be displayed on the display device 21 together with the first detection result image 22 and the second detection result image 23 when the horizontal detection is performed.

[0088] Here, the first detection result image 22, the second detection result image 23, and the third detection result image 24 will be described with reference to Fig. 6. Fig. 6 is a diagram showing a schematic example of a display screen displayed on the display device 21 when the ultrasonic sonar device 1 performs horizontal detection as a sonar function.

[0089] As shown in FIG. 6, when the ultrasonic sonar device 1 performs horizontal detection as a sonar function, a first detection result image 22, a second detection result image 23, and a third detection result image 24 are displayed on a display device 21.

[0090] The first detection result image 22 is a generally known detection result image as a result image of horizontal detection, and is a circular detection result image that displays the latest detection results in each azimuth direction for the omnidirectional detection of the ship 71. Specifically, the latest detection results over a predetermined range set in all azimuth directions of the ship 71 are displayed on the display device 21 as the first detection result image 22 based on the reception signals for each direction of the first central axes C1a to C1f of the first transducers 52a to 52f output from the filter 14 and the virtual reception signals for each direction virtually set between those directions.

[0091] The first detection result image generating means 15 generates a first detection result image 22 using the filtered reception signals of the first transducers 52a to 52f input from the filter 14 and virtual reception signals for each virtually set direction. The user can determine in which direction the detection target GF currently exists with respect to the ship 71 from the first detection result image 22 displayed on the display device 21.

[0092] The second detection result image 23 is an image in which the detection results of the first range are arranged in chronological order like a fish finder, based on the received signals of the first transducers 52a-52f having the first central axes C1a-C1f in a predetermined direction included in the first range out of a predetermined range set in all directions around the ship 71, i.e., out of the first central axes C1a-C1f, which are included in the first range.

[0093] In addition, the third detection result image 24 is an image in which the detection results of the second range are arranged in chronological order like a fish finder, based on the received signals of the first transducers 52a-52f having the first central axes C1a-C1f in a predetermined direction included in a second range different from the first range among the predetermined ranges set in all directions around the ship 71, i.e., among the first central axes C1a-C1f, a range included in the second range.

[0094] Since the first detection result image 22 includes only detection results at a certain time point for at least each of the predetermined directions (first central axes C1a to C1f), there is a risk that the detection target GF will be frequently overlooked. In response to this, a second detection result image 23 in which the detection results of the first range are arranged in time series based on the received signal in a predetermined direction included in the first range of the predetermined range is generated by the second detection result image generating means 16 and displayed on the display device 21. Also, a third detection result image 24 in which the detection results of the second range are arranged in time series based on the received signal in a predetermined direction included in the second range of the predetermined range is generated by the third detection result image generating means 17 and displayed on the display device 21.

[0095] As a result, the detection result history of the detection target GF that was present in the first range remains in the second detection result image 23, and the detection result history of the detection target GF that was present in the second range remains in the third detection result image 24. This makes it possible to prevent the detection target GF from being overlooked, which would be the case if only the first detection result image 22 was displayed. In addition, since both the second detection result image 23 corresponding to the first range and the third detection result image 24 corresponding to the second range are generated and displayed on the display device 21, it is possible to easily grasp in which range the detection target GF was present, including in the past, while preventing the detection target GF from being overlooked.

[0096] The first range may be set to, for example, half of the range on the starboard side of the ship 71 among all directions relative to the ship 71, and the second range may be set to half of the range on the port side of the ship 71 among all directions relative to the ship 71. In this case, the predetermined directions included in the first range are the first central axes C1b, C1a, and C1f, and the predetermined directions included in the second range are the first central axes C1c, C1d, and C1e (see FIG. 4(a)).

[0097] Therefore, in this case, the second detection result image generating means 16 generates one detection result line by combining the reception signals of the first transducers 52b, 52a, 52f for each depth, and arranges them in chronological order so that the right side is the oldest detection result line and the left side is the newest detection result line to generate a second detection result image 23 similar to the detection result image of a fish finder. Also, the third detection result image generating means 17 generates one detection result line by combining the reception signals of the first transducers 52c, 52d, 52e for each depth, and arranges them in chronological order so that the right side is the oldest detection result line and the left side is the newest detection result line to generate a third detection result image 24 similar to the detection result image of a fish finder.

[0098] As a result, the second detection result image 23 retains the history of the detection results of the detection target GF that was present in the range on the starboard side of the ship 71, and the third detection result image 24 retains the history of the detection results of the detection target GF that was present in the range on the port side of the ship 71. Therefore, it is possible to easily grasp whether the detection target GF was present on the starboard side or the port side of the ship 71, including in the past.

[0099] Moreover, the first range may be set to a half of the range on the forward side of the ship 71 among all directions relative to the ship 71, and the second range may be set to a half of the range on the rearward side of the ship 71 among all directions relative to the ship 71. In this case, the predetermined direction included in the first range is the first central axes C1b and C1c, and the predetermined direction included in the second range is the first central axes C1e and C1f (see FIG. 4(a)).

[0100] Therefore, in this case, the second detection result image generating means 16 generates one detection result line by combining the reception signals of the first transducers 52b, 52c for each depth, and arranges them in chronological order so that the right side is the oldest detection result line and the left side is the newest detection result line to generate a second detection result image 23 similar to the detection result image of a fish finder. Also, the third detection result image generating means 17 generates one detection result line by combining the reception signals of the first transducers 52e, 52f for each depth, and arranges them in chronological order so that the right side is the oldest detection result line and the left side is the newest detection result line to generate a third detection result image 24 similar to the detection result image of a fish finder.

[0101] As a result, the second detection result image 23 retains the detection result history of the detection target GF that was present in the range on the front side of the ship 71, and the third detection result image 24 retains the detection result history of the detection target GF that was present in the range on the rear side of the ship 71. As a result, it is possible to easily grasp whether the detection target GF was present on the front side of the ship 71 or on the rear side, including in the past.

[0102] In this case, the second detection result image 23 may be generated using the reception signals of the first transducers 52a, 52b, 52c, and 52d, with the first central axes C1a, C1b, C1c, and C1d being the predetermined directions included in the first range. Also, the third detection result image 24 may be generated using the reception signals of the first transducers 52d, 52e, 52f, and 52a, with the first central axes C1d, C1e, C1f, and C1a being the predetermined directions included in the second range. In this case, either the second detection result image 23 or the third detection result image 24 may include the reception signals of the first transducers 52a and 52d, or both the second detection result image 23 and the third detection result image 24 may include the reception signals of the first transducers 52a and 52d. With these, the detection results in all directions in which the reflected waves of the ultrasonic waves TB are received can be included in at least one of the second detection result image 23 and the third detection result image 24.

[0103] The first range may be set in all directions relative to the ship 71, and may be a predetermined direction in which all the first central axes C1a to C1f are included in the first range. That is, the first range, which is the detection range of the detection result shown in the second detection result image 23, may be the same as the predetermined range, which is the detection range of the detection result shown in the first detection result image 22. In this case, the second detection result image generating means 16 generates one detection result line by synthesizing the reception signals of all the first transducers 52a to 52f for each depth, and arranges the detection result lines in chronological order so that the right side is the oldest detection result line and the left side is the latest detection result line, thereby generating the second detection result image 23 equivalent to the detection result image of the fish finder.

[0104] As a result, the detection result history of the detection target GF that existed within the detection range (i.e., a specified range) of the detection result shown by the first detection result image 22 remains in the second detection result image 23, thereby preventing the detection target GF from being overlooked within that specified range.

[0105] When the first range is set to all directions relative to the ship 71, the second detection result image generating means 16 may generate one detection result line by combining not only the reception signals of all the first transducers 52a-52f but also the reception signal of the second transducer 53 for each depth, and generate a second detection result image 23 similar to the detection result image of a fish finder. The reception signals of the first transducers 52a-52f also include detection results in the vertical direction directly below the ship 71, but by generating the second detection result image 23 including the reception signal of the second transducer 53, the detection results in the vertical direction can be reflected in the second detection result image 23 with high sensitivity.

[0106] Furthermore, when the first range is set to all directions relative to the ship 71, the third detection result image generating means 17 may not generate the third detection result image 24 and may not display the third detection result image 24 on the display device 21. Furthermore, the third detection result image generating means 17 may generate a detection result image of the vertical direction directly below the ship 71 as the third detection result image 24 based on the received signal of the second transducer 53 and display the third detection result image 24 on the display device 21. In the latter case, the user can grasp the presence or absence of a detection target GF in the vertical direction directly below the ship 71 going back to the past through the third detection result image 24.

[0107] When the first range indicated by the second detection result image 23 is set in all directions relative to the ship 71, the ultrasonic sonar device 1 may allow the user to set whether or not to include the detection result of the second transducer 53 in the second detection result image 23. When the first range indicated by the second detection result image 23 is set in all directions relative to the ship 71, the ultrasonic sonar device 1 may allow the user to set whether or not to display the third detection result image 24 as the detection result in the vertical direction directly below the ship 71.

[0108] In addition, the ultrasonic sonar device 1 may allow the user to set whether the first range shown by the second detection result image 23 and the second range shown by the third detection result image 24 are on the starboard / port side of the ship 71, or the front / rear side of the ship 71, and also whether the first range shown by the second detection result image 23 is in all directions relative to the ship 71.

[0109] The display control means 18 performs control for displaying the first detection result image 22 generated by the first detection result image generating means 15, the second detection result image 23 generated by the second detection result image generating means 16, and the third detection result image 24 generated by the third detection result image generating means 17 on the display device 21. For example, the display control means 18 adjusts the sizes and display positions of the first detection result image 22, the second detection result image 23, and the third detection result image 24, and also combines characters, symbols, figures, etc. with these images to display one image on the display device 21.

[0110] Next, a method of performing horizontal detection using the sonar function of the ultrasonic sonar device 1 of this embodiment configured as described above will be described.

[0111] When a user turns on the power to the ultrasonic sonar device 1 via the operation button 31, or when the power is turned on and an instruction is given to start performing horizontal detection using the sonar function, the ultrasonic sonar device 1 first drives the lifting device 41 to make the transmitting and receiving unit 50 appear underwater from the bottom of the ship 71.

[0112] The ultrasonic sonar device 1 outputs drive signals from the transmission units 11a and 11b to transmit ultrasonic waves TB in the directions of the first central axes C1a to C1f and the second central axis C2, respectively, from the first transducers 52a to 52f and the second transducer 53 of the wave transmitting and receiving unit 50 for a predetermined time. Due to the directional characteristics of the ultrasonic waves TB transmitted from each of the first central axes C1a to C1f, the ultrasonic waves TB are transmitted in all directions to the ship 71.

[0113] The ultrasonic waves TB transmitted from the first transducers 52a-52f and the second transducer 53 are reflected from the detection target GF and the water bottom SB present within a predetermined range from which the ultrasonic waves TB are transmitted. The reflected waves are received by the first transducers 52a-52f and the second transducer 53, and signals (voltages) are output from the first transducers 52a-52f and the second transducer 53 as the intensities of the reflected waves received in the directions of the first central axes C1a-C1f and the second central axis C2, respectively.

[0114] The signals (voltages) output from the first oscillators 52a to 52f and the second oscillator 53 are amplified by the corresponding receiving units 13a to 13g, converted into digital signals (digital values), and output as received signals (original received signals) in each direction of the first center axes C1a to C1f and the second center axis C2.

[0115] These original reception signals are subjected to spatial (and temporal) filtering by the filter 14. In addition, the filter 14 sets a virtual direction at a midpoint between adjacent first center axes C1a-C1f with respect to each of the first center axes C1a-C1f, and generates reception signals from the reception signals of the first transducers 52a-52f, on the assumption that an ultrasonic wave TB is virtually transmitted and received in the virtual direction.

[0116] The filtered received signals in the directions of the first center axes C1a to C1f and the second center axis C2 output by the filter 14, and virtual received signals in virtual directions virtually set between each of the first center axes C1a to C1f, are input to a first detection result image generating means 15, a second detection result image generating means 16, and a third detection result image generating means 17.

[0117] Then, a first detection result image 22 in which the latest detection results in each azimuth direction are displayed as a circular detection result image for the omnidirectional detection of the ship 71 is generated by the first detection result image generating means 15. Also, a second detection result image 23 in which the detection results in the first range are arranged in chronological order like a fish finder based on the received signals in a predetermined direction included in the first range among the predetermined ranges set in omnidirectional directions for the ship 71 is generated by the second detection result image generating means 16. Furthermore, a third detection result image 24 in which the detection results in the second range are arranged in chronological order like a fish finder based on the received signals in a predetermined direction included in the second range among the predetermined ranges set in omnidirectional directions for the ship 71 is generated by the third detection result image generating means 17.

[0118] The first detection result image 22, the second detection result image 23, and the third detection result image 24 are displayed on the display device 21 by the display control means 18 as shown in FIG.

[0119] Here, a method for generating the second detection result image 23 in the second detection result image generating means 16 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the second detection result image generating process executed by the second detection result image generating means 16. Note that a method for generating the third detection result image 24 in the third detection result image generating means 17 is the same as the method for generating the second detection result image 23 in the second detection result image generating means 16, except that the first range is replaced with the second range, and therefore a description thereof will be omitted.

[0120] The second detection result image generating means 16 starts execution of a second detection result image generating process when it receives filtered reception signals in the directions of the first center axes C1a to C1f and the second center axis C2 from the filter 14. When the second detection result image generating means 16 starts execution of the second detection result image generating process, it first specifies a first range (S1). As the first range, any one of the starboard side, the front side, and all directions of the ship 71 is set. In addition, in the third detection result image generating process, any one of the port side, the rear side, and the vertical direction directly below the ship 71 is set as the second range.

[0121] Next, the second detection result image generating means 16 identifies a predetermined direction included in the first range identified in the process of S1 from among the first central axes C1a to C1f (S2). For example, when the starboard side of the ship 71 is identified as the first range, the first central axes C1b, C1a, and C1f are identified as the predetermined direction included in the first range. When the front side of the ship 71 is identified as the first range, the first central axes C1b and C1c, or the first central axes C1a, C1b, C1c, and C1d are identified as the predetermined direction included in the first range. When all directions with respect to the ship 71 are identified as the first range, all of the first central axes C1a to C1f, or all of the first central axes C1a to C1f and the second central axis C2 are identified as the predetermined direction included in the first range.

[0122] In the third detection result image generation process, when the port side of the ship 71 is specified as the second range, the first central axes C1c, C1d, and C1e are specified as the predetermined direction included in the second range. When the rear side of the ship 71 is specified as the second range, the first central axes C1e and C1f or the first central axes C1d, C1e, C1f, and C1a are specified as the predetermined direction included in the second range. When the vertical direction directly below the ship 71 is specified as the second range, the second central axis C2 is specified as the predetermined direction included in the first range.

[0123] Next, the second detection result image generating means 16 sets the variable i to 0 (S3). The variable i is a variable that indicates a depth position, and when the variable i is 0, it indicates the shallowest depth among the received signals in each predetermined direction, and as the value of the variable i increases, it indicates a deeper depth, and when the variable i is at the maximum value imax, it indicates the deepest depth among the received signals in each predetermined direction. Subsequent processing is performed on the received signals at all depths while incrementing the variable i by 1.

[0124] That is, the second detection result image generating means 16 acquires reception signals at the depth specified by the variable i in all predetermined directions included in the first range specified in S2 (S4).Then, the second detection result image generating means 16 selects the maximum level among the levels of the reception signals at the depth specified by the variable i acquired by the process of S4, thereby synthesizing the reception signals at the depth specified by the variable i in all predetermined directions included in the first range into one (S5).

[0125] Next, the second detection result image generating means 16 adds 1 to the variable i to advance the depth to be processed in S4 and S5 (S6). The second detection result image generating means 16 then determines whether the variable i after the process of S6 (after the addition) is greater than the maximum value imax (S7), and if the variable i is equal to or less than the maximum value imax (S7: No), executes the processes of S4 and S5 on the received signal at the depth specified by the variable i after the addition. That is, the processes of S4 and S5 are performed on the received signals at all depths specified by the variable i=0 to imax in all predetermined directions included in the first range specified in S2, and by selecting the maximum level among the levels of the received signals at each depth, each received signal in the predetermined direction included in the first range is synthesized into one.

[0126] Then, if the result of the judgment in S7 is that the variable i is greater than the maximum value imax (S7: Yes), this means that synthesis of received signals has been performed at all depths within the first range, so the second detection result image generating means 16 generates a detection result line in which the synthesized received signals are arranged in the depth direction (S8).

[0127] In the process of S2, if the first range contains only one predetermined direction (for example, in the second range, only the second central axis C2 may occur as the predetermined direction. Also, depending on the setting ranges of the first and second ranges and the arrangement of the first transducers 52a-52f, there may be cases where the first and second ranges contain only one predetermined direction), there is no need to combine the received signals of each predetermined direction, so the processes of S3-S7 may be skipped and the process of S2 may proceed to the process of S8. In this case, the process of S8 generates a detection result line directly from the received signals in that one direction.

[0128] Then, the second detection result image generation means 16 arranges the detection result lines generated in the processing of S8 in chronological order with the oldest detection result line on the right side and the most recent detection result line on the left side, to generate a second detection result image 23 similar to the detection result image of a fish finder device (S9), and terminates the second detection result image generation processing.

[0129] According to the ultrasonic sonar device 1 configured as above, ultrasonic waves TB are transmitted from the first transducers 52a-52f and the second transducer 53 into the water in all directions relative to the ship 71 set in a predetermined range by the wave transmitting and receiving unit 50. Then, the reflected waves of the ultrasonic waves TB reflected from each position in the water for each of the first central axes C1a-C1f and the second central axis C2, which are predetermined directions, are received by the first transducers 52a-52f and the second transducer 53 of the wave transmitting and receiving unit 50, respectively. Based on the reflected waves received by the wave transmitting and receiving unit 50, reception signals are generated for each predetermined direction by the reception units 13a-13g and the filter 14.

[0130] Based on the generated reception signals for each predetermined direction, a first detection result image 22 showing the latest detection result over a predetermined range is generated by the first detection result image generating means 15. From this first detection result image 22, it is possible to determine at least the presence or absence of a detection target GF within the predetermined range and the direction in which the detection target GF currently exists.

[0131] Meanwhile, a second detection result image 23 in which the detection results of the first range are arranged in chronological order is generated by the second detection result image generating means 16 based on a received signal in a predetermined direction included in a first range of the predetermined range. This leaves a history of the detection results of the detection target GF that existed in the first range in the second detection result image 23. This makes it possible to prevent the detection target GF from being overlooked.

[0132] Further, a third detection result image 24 in which the detection results of the second range are arranged in chronological order is generated by the third detection result image generating means 17 based on a received signal in a predetermined direction included in a second range different from the first range among the predetermined ranges. As a result, not only does the history of the detection results of the detection target GF that existed in the first range remain in the second detection result image 23, but the history of the detection results of the detection target GF that existed in the second range remains in the third detection result image 24. Therefore, it is possible to easily grasp in which range the detection target GF has existed, including in the past, while suppressing overlooking the detection target GF.

[0133] Furthermore, when the first range and / or the second range includes a plurality of predetermined directions, the reception signals for each of the plurality of predetermined directions are combined, and based on the combined reception signals, the second detection result image generating means 16 generates the second detection result image 23, and the third detection result image generating means 17 generates the third detection result image 24. Therefore, the detection results of the detection target GF based on the transmission and reception of ultrasonic waves TB performed for each of the plurality of predetermined directions included in the first range and / or the second range are included without omission in the second detection result image 23 or the third detection result image 24, and further the history of the detection results remains in the second detection result image 23 or the third detection result image 24, so that it is possible to more reliably prevent the detection target GF from being overlooked.

[0134] Furthermore, the synthesis of received signals performed by the second detection result image generating means 16 or the third detection result image generating means 17 is performed by selecting the maximum level from the levels of the multiple received signals to be synthesized for each depth. This makes it possible to reliably display reflected waves with high reflection intensity that are likely to be a detection target GF in the second detection result image 23 or the third detection result image 24. This makes it possible to more reliably prevent the detection target GF from being overlooked.

[0135] Furthermore, the ultrasonic sonar device 1 according to this embodiment achieves the above-mentioned effects through other configurations.

[0136] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and it can be easily assumed that various improvements and modifications are possible within the scope of the present invention. For example, each embodiment may be modified by adding a part or a plurality of parts of the configuration of each other embodiment to the embodiment, or by replacing a part or a plurality of parts of the configuration of the embodiment, including the modified examples described below. In addition, the numerical values ​​given in the above embodiments are merely examples, and other numerical values ​​can be naturally adopted.

[0137] In the above embodiment, the case where the second transducer 53 having the second central axis C2 in the vertical direction directly below the ship 71 has been described, but when performing horizontal detection as at least a sonar function, there may be cases where detection in the vertical direction directly below the ship 71 is not necessarily required. In addition, in the above embodiment, since the directional characteristics of the ultrasonic waves TB transmitted from the first transducers 52a to 52f include the vertical direction directly below the ship 71, the detection target GF present in the vertical direction directly below the ship 71 can be detected only by the first transducers 52a to 52f, although the detection sensitivity and / or accuracy is reduced. Therefore, the second transducer 53 may be omitted from the wave transmission and reception unit 50.

[0138] In the above embodiment, the first transducers 52a-52f are inclined with their acoustic radiation surfaces facing inward (towards the side where the second transducer 53 is located), but this is not necessarily limited to the above, and the first transducers 52a-52f may be inclined with their acoustic radiation surfaces facing outward (towards the side opposite to the side where the second transducer 53 is located). In this case, too, it is preferable that each of the first central axes C1a-C1f forms a predetermined angle θ with the second central axis C2 (the vertical direction when the wave transmitting and receiving unit 50 is attached to the ship 71) selected from the range of 20° or more and 50° or less.

[0139] In the above embodiment, the case has been described in which the first transducers 52a to 52f are arranged around the second transducer 53 in the wave transmitting and receiving unit 50. However, the method of arranging the first transducers 52a to 52f and the second transducer 53 in the wave transmitting and receiving unit 50 may be arbitrary, as long as, from a broad perspective, when the wave transmitting and receiving unit 50 is attached to the ship 71, the second central axis C2 is in the vertical direction, the first central axes C1a to C1f form a predetermined angle θ with respect to the second central axis C2 (in other words, the vertical direction), and the first central axes C1a to C1f are in a predetermined direction. For example, the first oscillators 52a to 52f and the second oscillator 53 may be arranged in one row or two rows, or the first oscillators 52a to 52f may be arranged in two rows and the second oscillator 53 may be arranged at any position between the two rows of the first oscillators 52a to 52f.

[0140] In the above embodiment, a case has been described in which detection is performed over a predetermined range set in all directions of the ship 71, but the predetermined range may be set in a portion of all directions of the ship 71. In this case, the first range may be set to a portion or the entirety of the predetermined range. Furthermore, the second range may be set to a portion or the entirety of the predetermined range as long as it is different from the first range.

[0141] In the above embodiment, a case has been described in which the number of first transducers 52 in the transmitting / receiving unit 50 is reduced, and ultrasonic waves TB are transmitted and received from the first transducers 52 simultaneously over a predetermined range set in all directions of the ship 71 to perform horizontal detection. However, the present invention, which displays not only the first detection result image 22 but also the second detection result image 23 and the third detection result image 24 on the display device 21, can also be applied to detection using PPI sonar or scanning sonar. [Explanation of symbols]

[0142] 1. Ultrasonic sonar device 11a Transmitting unit 11b Transmitting unit 13a Receiving unit 13b Receiving unit 13c Receiving unit 13d Receiving unit 13e Receiving unit 13f Receiving unit 13g receiving unit 14 Filters 15 First detection result image generating means 16 Second detection result image generating means 17 Third detection result image generating means 18 Display control means 21 Display device 22 First detection result image 23 Second detection result image 24 Third detection result image 50 Transmitter / receiver unit 52 First transducer 52a First transducer 52b First transducer 52c 1st transducer 52d First transducer 52e First transducer 52f 1st transducer 53 Second transducer 71 Ship C1a 1st central axis C1b 1st central axis C1c 1st central axis C1d 1st central axis C1e 1st center axis C1f 1st central axis C2 2nd central axis GF Detectable object TB ultrasound

Claims

1. a wave transmitting / receiving unit capable of transmitting ultrasonic waves over a predetermined range underwater and receiving reflected waves of the ultrasonic waves reflected from each position underwater in each predetermined direction; a reception signal generating means for generating a reception signal for each of the predetermined directions based on the reflected wave received by the wave transmitting / receiving unit; a first detection result image generating means for generating a first detection result image showing the latest detection result over the predetermined range based on the reception signals for each of the predetermined directions generated by the reception signal generating means; a second detection result image generating means for generating a second detection result image in which detection results in the first range are arranged in time series based on the received signal in the predetermined direction included in a first range of the predetermined range, The second detection result image generating means includes: When the first range includes a plurality of the predetermined directions, the reception signals for the plurality of the predetermined directions are synthesized, and the second detection result image is generated based on the synthesized reception signals, An ultrasonic sonar device characterized in that the synthesis of the received signals is performed by selecting, for each depth, the maximum level from among the levels of the plurality of received signals to be synthesized.

2. 2. The ultrasonic sonar device according to claim 1, wherein the first range is the same as the predetermined range.

3. 2. The ultrasonic sonar device according to claim 1, further comprising a third detection result image generating means for generating a third detection result image in which detection results of the second range are arranged in chronological order based on the received signal in the specified direction included in a second range different from the first range among the specified ranges.

4. the first range is a range on the starboard side of the ship on which the wave transmitting and receiving unit is provided, 4. The ultrasonic sonar device according to claim 3, wherein the second range is a range on the port side of the ship.

5. the first range is a range on a front side of the ship on which the wave transmitting and receiving unit is provided, 4. The ultrasonic sonar device according to claim 3, wherein the second range is a range on the rear side of the ship.

6. The wave transmitting and receiving unit includes: A plurality of first transducers having a predetermined directional characteristic are provided, The ultrasonic sonar device according to claim 1, characterized in that each of the multiple first transducers has a central axis that is in the predetermined direction and is fixed so that the central axis is positioned at a predetermined angle with respect to the vertical direction when the transmitting and receiving unit is attached to the ship, and has the predetermined directional characteristic so as to include at least the central axes of adjacent first transducers and the vertical direction.

7. The wave transmitting and receiving unit includes:

7. The ultrasonic sonar device according to claim 6, further comprising a second transducer fixed so that its central axis is positioned in a vertical direction when the sonar device is attached to a ship.

8. a transmission unit that distributes a drive signal for transmitting the ultrasonic waves from the first transducers of the wave transmitting and receiving unit to the first transducers via a diode, thereby simultaneously driving the first transducers; The ultrasonic sonar device according to claim 6, further comprising: a receiving unit provided corresponding to each of the plurality of first transducers of the transmitting and receiving unit, which captures the signal output by the corresponding first transducer receiving the reflected wave and performs predetermined processing on the signal.