Ultrasonic sonar device

Abstract

An ultrasonic sonar device 1 comprises first oscillators 52a-52f and a second oscillator 53 capable of transmitting an ultrasonic wave over a predetermined range in water and receiving a reflected wave of the ultrasonic wave reflected from each position in water for each predetermined direction, reception units 13a-13g and a filter 14 that generate a reception signal for each predetermined direction on the basis of the reflected wave received by each of the first oscillators 52a-52f and the second oscillator 53, a first detection result image generation means 15 that generates a first detection result image indicating the latest detection result over the predetermined range on the basis of the generated reception signals for each predetermined direction, and a second detection result image generation means 16 that generates a second detection result image in which the detection results in a first range in the predetermined range are arranged in time series on the basis of the reception signals in a predetermined direction included in the first range.

Description

Ultrasonic sonar device

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

[0002] Ultrasonic sonar devices that detect detection targets such as fish schools over a predetermined range in water by transmitting and receiving ultrasonic waves are known. While general fish school detection devices detect detection targets in the vertical direction from a ship, ultrasonic sonar devices can detect detection targets existing around the ship, such as horizontal detection and vertical cross-section detection. As ultrasonic sonar devices, for example, PPI sonars (searchlight sonars) and scanning sonars are known.

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

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

[0005] Japanese Patent Application Laid-Open No. 2019-066208, Japanese Patent Application Laid-Open No. 2019-200204

[0006] In ultrasonic sonar systems, when performing horizontal detection, the detection results for each azimuth direction are displayed as a circular detection result image, and when performing vertical cross-sectional detection, the detection results for each elevation angle direction are displayed as a fan-shaped (or triangular) detection result image. In the case of PPI sonar, each time ultrasonic waves are transmitted and reflected waves are received in a particular direction, the detection result for that direction is overwritten on the detection image. That is, with PPI sonar, the latest detection result for each direction is shown on the detection image. In the case of scanning sonar, each time ultrasonic waves are transmitted and reflected waves are received simultaneously in each direction, the detection results for all directions are overwritten on the detection image.

[0007] Thus, ultrasonic sonar devices only contain detection results for a specific point in time, at least for each direction, leading to frequent missed detections of fish. Traditionally, to solve this problem, vertical detection has also been performed, and the devices have been used in conjunction with general fish finders that retain a history of detection results. However, because general fish finders and sonar (PPI sonar and scanning sonar) detect different locations, the above problem has not been fundamentally solved.

[0008] This invention was made to solve these problems and aims to provide an ultrasonic sonar device that can reduce the chance of overlooking objects being detected.

[0009] To achieve this objective, a first aspect of the present invention is an ultrasonic sonar device comprising: a transmitting and receiving unit capable of transmitting ultrasonic waves over a predetermined range in water and receiving reflected ultrasonic waves reflected from each position in the water for each predetermined direction; a receiving signal generation means that generates a received signal for each predetermined direction based on the reflected waves received by the transmitting and receiving unit; a first detection result image generation means that generates a first detection result image showing the latest detection results over the predetermined range based on the received signals for each predetermined direction generated by the receiving signal generation means; and a second detection result image generation means that 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 the predetermined directions included in the first range within the predetermined range.

[0010] A second aspect of the present invention is an ultrasonic sonar device according to the first aspect, wherein the second detection result image generation means, when the first range includes a plurality of predetermined directions, synthesizes the received signals for each of the plurality of predetermined directions and generates a 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 synthesis of the received signals is performed by selecting the maximum level from among a plurality of levels of the received signals to be synthesized for each depth.

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

[0013] A fifth aspect of the present invention is an ultrasonic sonar device according to any of the first to fourth aspects, comprising a third detection result image generation 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 signals in the predetermined direction that are included in the second range which is different from the first range among the predetermined ranges.

[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 the vessel on which the transmitting and receiving unit is installed, and the second range covers the port side of the vessel.

[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 area in front of the vessel on which the transmitting and receiving unit is installed, and the second range covers the area in rear of the vessel.

[0016] An eighth aspect of the present invention is an ultrasonic sonar device according to any of the first to seventh aspects, wherein the transmitting and receiving unit comprises a plurality of first transducers having predetermined directional characteristics, each of the plurality of first transducers having its central axis in the predetermined direction and fixed such that, when the transmitting and receiving unit is attached to a ship, its central axis is positioned at a predetermined angle with respect to the vertical direction, and has the predetermined directional characteristics to include at least the central axis of an adjacent first transducer 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 comprises a second transducer fixed such that its central axis is positioned vertically when attached to a ship.

[0018] A tenth aspect of the present invention is an ultrasonic sonar device according to the eighth or ninth aspect, comprising: a transmitting unit that simultaneously drives a plurality of first transducers of the transmitting and receiving unit by distributing a drive signal for transmitting the ultrasonic waves from the plurality of first transducers to the plurality of first transducers via a diode; and a receiving unit provided corresponding to each of the plurality of first transducers of the transmitting and receiving unit, which receives a signal output when the corresponding first transducer receives the reflected wave and performs predetermined processing.

[0019] According to the ultrasonic sonar device of the first aspect of the present invention, ultrasonic waves are transmitted over a predetermined range in the water by a transmitting / receiving unit. Reflected ultrasonic waves reflected from each position in the water in each predetermined direction are received by the transmitting / receiving unit. Based on the reflected waves received by the transmitting / receiving unit, a received signal is generated by a received signal generation means for each predetermined direction. Based on the generated received signals for each predetermined direction, a first detection result image showing the latest detection results over the predetermined range is generated by a first detection result image generation means. From this first detection result image, it is possible to determine the presence or absence of a target object in the predetermined range and the direction in which the target object is located. On the other hand, based on the received signals in a predetermined direction included in the first range within the predetermined range, a second detection result image is generated by a second detection result image generation means, which arranges the detection results of the first range in chronological order. As a result, the history of detection results of targets that were present in the first range remains in the second detection result image. Therefore, there is an effect in suppressing the oversight of targets.

[0020] The ultrasonic sonar device according to the second embodiment provides the following effects in addition to the effects of the ultrasonic sonar device according to the first embodiment. Specifically, when the first range includes a plurality of predetermined directions, the received signals for each of the plurality of predetermined directions are combined, and a second detection result image is generated by the second detection result image generation means based on the combined received signals. Therefore, the detection results of the objects to be detected based on the transmission and reception of ultrasound performed for each of the plurality of predetermined directions included in the first range are included without omission in the second detection result image, and furthermore, the history of the detection results is retained in the second detection result image, which has the effect of more reliably suppressing the oversight of objects to be detected.

[0021] The ultrasonic sonar device according to the third embodiment provides the following effects in addition to the effects of the ultrasonic sonar device according to the second embodiment. Specifically, the synthesis of received signals performed by the second detection result image generation means is carried out by selecting the maximum level from among the levels of multiple received signals to be synthesized for each depth. As a result, reflected waves with high reflection intensity, which are likely to be those of the object to be detected, can be reliably represented in the second detection result image. Therefore, there is an effect in which the oversight of the object to be detected can be more reliably suppressed.

[0022] The ultrasonic sonar device according to the fourth embodiment provides the following effect in addition to the effect of the ultrasonic sonar device according to any of the first to third embodiments. 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. As a result, the history of the detection results of objects that were present in the detection range of the detection result shown in the first detection result image (i.e., the predetermined range) is recorded in the second detection result image, which has the effect of suppressing the oversight of objects that extend over that predetermined range.

[0023] The ultrasonic sonar device according to the fifth embodiment provides the following effects in addition to the effects of the ultrasonic sonar device according to any of the first to fourth embodiments. Specifically, a third detection result image is generated by the third detection result image generation means, which arranges the detection results of the second range in chronological order based on the received signal in a predetermined direction included in a second range that is different from the first range within a predetermined range. As a result, not only is the history of the detection results of objects present in the first range preserved in the second detection result image, but the history of the detection results of objects present in the second range is also preserved in the third detection result image. Therefore, it is possible to suppress the oversight of objects while making it easier to understand which ranges objects have been present in, including in the past.

[0024] The ultrasonic sonar device according to the sixth embodiment provides the following effects in addition to the effects of the ultrasonic sonar device according to the fifth embodiment. Specifically, the second detection result image retains the history of detection results of objects that were located in the starboard side range of the vessel where the transmitting and receiving unit is installed, as the first range, and the third detection result image retains the history of detection results of objects that were located in the port side range of the vessel, as the second range. This has the effect of making it easy to determine whether the object was located on the starboard side or the port side of the vessel, including in the past.

[0025] The ultrasonic sonar device according to the seventh embodiment provides the following effects in addition to the effects of the ultrasonic sonar device according to the fifth or sixth embodiment. Specifically, the second detection result image retains the history of detection results of objects that were located in the forward range of the vessel where the transmitting and receiving unit is installed, as the first range, and the third detection result image retains the history of detection results of objects that were located in the aft range of the vessel, as the second range. This has the effect of making it easy to determine whether the object was located in the forward or aft range of the vessel, including in the past.

[0026] The ultrasonic sonar device according to the eighth embodiment provides the following effects in addition to the effects of the ultrasonic sonar device according to any of the first to seventh embodiments. Specifically, a plurality of first transducers are fixed in the transmitting and receiving unit such that their central axes are in a predetermined direction and, when the transmitting and receiving unit is attached to a ship, their central axes are positioned at a predetermined angle with respect to the vertical direction. Each first transducer has predetermined directional characteristics that include at least the central axis of an adjacent first transducer and the vertical direction. As a result, ultrasonic waves can be transmitted simultaneously over a predetermined range with a small number of first transducers, and the reflected waves can be received to detect objects. 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 embodiment provides the following effects in addition to those of the ultrasonic sonar device according to the eighth embodiment. Specifically, in addition to the first transducer, a second transducer is provided on the transducer unit, which is fixed so that its central axis is located vertically when the transducer unit is attached to a ship. This has the effect of enabling detection of objects in the vertical direction with high accuracy.

[0028] The ultrasonic sonar device according to the tenth embodiment provides the following effects in addition to the effects of the ultrasonic sonar device according to the eighth or ninth embodiment. Specifically, the drive signal for transmitting ultrasonic waves from multiple first transducers of the transmitting / receiving unit is distributed to multiple first transducers via diodes by the transmitting unit, and the multiple first transducers are driven simultaneously. Furthermore, the signal output by the corresponding first transducer when it receives the reflected wave is captured by a receiving unit provided in conjunction with each of the multiple first transducers of the transmitting / receiving unit, and a predetermined processing is performed. As a result, multiple first transducers can be driven by a single transmitting unit, while the signals output from each first transducer can be processed individually, resulting in significant cost reduction and miniaturization.

[0029] This is a schematic diagram illustrating the configuration of an ultrasonic sonar device according to one embodiment of the present invention. This is a schematic diagram showing the state when a ship equipped with the ultrasonic sonar device performs underwater detection, viewed from the side. (a) is a schematic cross-sectional view showing the transducer unit of the ultrasonic sonar device, and (b) is a schematic perspective view showing the arrangement of a plurality of first transducers and second transducers constituting the transducer unit. (a) is a schematic diagram showing the first central axis of each of the first transducers when viewed vertically from above the ship, (b) is a schematic diagram showing the first central axis when viewed horizontally from the front of the ship, (c) is a schematic diagram showing the directional characteristics of the ultrasonic waves transmitted from the first transducers, and (d) is a diagram showing the directional characteristics of the ultrasonic waves transmitted from the first transducers when viewed from the front of the ship. This is a block diagram illustrating the electrical configuration of the ultrasonic sonar device. This is a schematic diagram showing an example of a display screen displayed on the display device of the ultrasonic sonar device. This is a flowchart showing the second detection result image generation process.

[0030] Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. The embodiments described below are all preferred specific examples of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement positions of components, and connection configurations shown in the following embodiments are examples and are not intended to limit the present invention. Accordingly, among the components in the following embodiments, those not described in the independent claims representing the highest-level concept of the present invention will be described as optional components. Furthermore, in each figure, substantially identical components are denoted by the same reference numerals, and redundant explanations are omitted or simplified.

[0031] First, an ultrasonic sonar device 1 according to one 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 the state when underwater detection is performed by a ship 71 equipped with the ultrasonic sonar device 1, viewed from the side.

[0032] As shown in Figures 1 and 2, the ultrasonic sonar device 1 is mounted on a vessel 71 and has at least a sonar function that horizontally detects objects GF, such as schools of fish, in a predetermined range around the vessel 71 in the water such as the sea, lake, or river in which the vessel 71 is floating. Horizontal detection involves detecting objects GF that are included in a predetermined range, with the entire direction as viewed from the vessel 71 being considered. In addition to horizontal detection, the ultrasonic sonar device 1 may also have a sonar function that performs vertical cross-sectional detection, or it may have a fish finder function that detects objects GF that are located in the vertical direction directly below the vessel 71 and displays the detection results in chronological order.

[0033] The ultrasonic sonar device 1 comprises a main body 5, an operation button 31 provided on the main body 5, a display device 21 integrally formed on the main body 5, a transmitter / receiver unit 50 for transmitting and receiving ultrasonic waves TB for detecting the object GF, and a lifting device 41 for raising and lowering the transmitter / receiver unit 50. The main body 5, the operation button 31, and the display device 21 are located in the wheelhouse of the ship 71, while the transmitter / receiver unit 50 and the lifting device 41 are located in the bottom of the ship 71. The transmitter / receiver unit 50 can be raised and lowered by the lifting device 41, allowing it to extend and retract from the bottom of the ship 71 into the water.

[0034] The operation button 31 is a button that can be operated by the user, and is used when the user gives various instructions or settings to the ultrasonic sonar device 1. For example, the user can turn the power of the ultrasonic sonar device 1 on / off, set the brightness of the image displayed by the display device 21, give instructions to start / stop the execution of horizontal detection by the sonar function, and set the detection range shown by the second detection result image 23 (hereinafter referred to as the "first range") and the detection range shown by the third detection result image 24 (hereinafter referred to as the "second detection range"), etc., via operation of the operation button 31.

[0035] As shown in Figure 2, the ultrasonic sonar device 1 transmits (irradiates) ultrasonic waves TB in a conical shape over a predetermined range from the transmitting / receiving unit 50, with the transmitting / receiving unit 50 protruding from the bottom of the ship 71. The transmitting / receiving unit 50 is configured to receive reflected ultrasonic waves TB reflected from objects to be detected GF, or from the seabed or lakebed (hereinafter collectively referred to as "seabed SB"), etc., within that predetermined conical range. The detailed configuration of the transmitting / receiving unit 50 will be described later with reference to Figures 3 and 4.

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

[0037] Next, the detailed configuration of the transmitting / receiving unit 50 will be described with reference to Figures 3 and 4. Figure 3(a) is a schematic cross-sectional view showing the transmitting / receiving unit 50, and Figure 3(b) is a schematic perspective view showing the arrangement of the multiple first transducers 52 (52a to 52f) and the second transducer 53 that constitute the transmitting / receiving unit 50.

[0038] Furthermore, Figure 4(a) schematically shows the first central axes C1a to C1f of the first transducers 52a to 52f as viewed vertically from above the ship 71, and Figure 4(b) schematically shows the first central axes C1a to C1f of the first transducers 52a to 52f as viewed horizontally from the front side of the ship 71. Furthermore, Figure 4(c) schematically shows the directional characteristics of the ultrasonic TB transmitted from adjacent first transducers 52a, 52b, and 52f, and Figure 4(d) shows the directional characteristics of the ultrasonic TB transmitted from the first transducer 52a and the first transducer 52d as viewed from the front side of the ship 71.

[0039] As shown in Figure 3, the transmitting and receiving unit 50 has a structure in which multiple (six in the example shown in Figure 3) first transducers 52 (first transducer 52a, first transducer 52b, first transducer 52c, first transducer 52d, first transducer 52e, first transducer 52f) and second transducers 53, which transmit ultrasonic TB in a predetermined direction and receive the reflected waves, are housed in a case 51 and molded. Each first transducer 52 is a disc-shaped structure having the same size and shape as the others. The second transducer 53 also has a disc shape similar to the first transducers 52. 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 it may be a different size from the first transducer 52.

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

[0041] The piezoelectric element 55 is a plate-shaped object made of piezoelectric ceramics, and for example, a disc-shaped plate-shaped object made of lead zirconate titanate (PZT) is used. The piezoelectric element 55 has a front side electrode (not shown) formed on the front surface, which is fully bonded to the substrate 54 via an adhesive layer (not shown), and a back side electrode (not shown) formed on the back surface facing the front surface. Lead wires are electrically connected to the front side electrode and the back side electrode, respectively.

[0042] When a driving voltage is applied to the piezoelectric element 55 by the front electrode and back electrode from the transmitting unit 11a or transmitting unit 11b (see Figure 5), which will be described later, it deforms in the thickness direction and vibrates the substrate 54. This vibration of the substrate 54 causes the first transducer 52 and the second transducer 53 to each generate ultrasonic TB.

[0043] Further, when the base material 54 vibrates due to the reflected wave of the ultrasonic TB, each of the first vibrator 52 and the second vibrator 53 causes the piezoelectric element 55 to deform due to the vibration, and a voltage is generated between the front-side electrode and the back-side electrode. The first vibrators 52a to 52f and the second vibrator 53 output the voltage generated between the front-side electrode and the back-side electrode to the corresponding reception units 13a to 13g described later, respectively, thereby generating reception signals corresponding to the reflected waves received by the respective first vibrators 52a to 52f and the second vibrator 53.

[0044] The case 51 has an opening at one end, and a plurality of first vibrators 52 and second vibrators 53 are housed in the case 51. The second vibrator 53 is disposed at the center of the case 51. Further, six first vibrators 52 are arranged around the second vibrator 53 in the counterclockwise order of the first vibrator 52a, the first vibrator 52b, the first vibrator 52c, the first vibrator 52d, the first vibrator 52e, and the first vibrator 52f as viewed from the front side of the base material 54. The acoustic radiation surfaces formed on the front surfaces of the base materials 54 of the respective first vibrators 52 and the acoustic radiation surface formed on the front surface of the base material 54 of the second vibrator 53 are all located on one virtual spherical surface.

[0045] In the present embodiment, the number of the first vibrators 52 is six, but the number of the first vibrators 52 may be any number of three or more, preferably four or more, more preferably six or more. However, when the number of the first vibrators 52 increases, the configuration of the ultrasonic sonar device 1 becomes complicated and the device becomes large-sized and expensive. Therefore, the number of the first vibrators 52 is preferably ten or less, and more preferably eight or less.

[0046] Here, it can be understood that the direction of the first central axis C1a, which is the central axis orthogonal to the front surface (acoustic radiation surface) of the base material 54, of the first oscillator 52a (which can also be said to be the direction of the normal vector of the first oscillator 52a) is the acoustic radiation direction. Similarly to the first oscillator 52a, a first central axis C1b is defined for the first oscillator 52b, a first central axis C1c is defined for the first oscillator 52c, a first central axis C1d is defined for the first oscillator 52d, a first central axis C1e is defined for the first oscillator 52e, and a first central axis C1f is defined for the first oscillator 52f. And it can be understood that the respective first central axes C1b to C1f are the acoustic radiation directions of the corresponding first oscillators 52b to 52f.

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

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

[0049] Here, the transmission / reception wave unit 50 is attached to the ship 71 such that the direction of the second central axis C2 of the second oscillator 53 is in the vertical direction. That is, the second oscillator 53 transmits (irradiates) ultrasonic waves TB toward the vertical direction directly below the ship 71. Due to the presence of this second oscillator 53, the ultrasonic sonar device 1 can detect the detection target GF in the vertical direction with high accuracy. The directivity characteristic of the ultrasonic wave TB transmitted from the second oscillator 53 preferably has a small directivity angle and a narrow beam shape. Thereby, the accuracy of detecting the detection target GF in the vertical direction can be further increased.

[0050] On the other hand, in the transmitting and receiving unit 50, as shown in Figure 3, the first transducers 52a to 52f are arranged with their acoustic radiation surfaces tilted such that the first central axes C1a to C1f make a predetermined angle θ with respect to the second central axis C2 (i.e., the vertical direction when the transmitting and receiving unit 50 is attached to the ship 71). As a result, the acoustic radiation direction of each of the first transducers 52a to 52f is oriented in a direction different from the vertical direction directly below the ship 71, as shown in Figure 4(b).

[0051] In this embodiment, each of the first transducers 52a to 52f is inclined so that their acoustic radiating surfaces face inward (towards the side where the second transducer 53 is located) (see Figure 3). In this case, each of the first central axes C1a to C1f is preferably at a predetermined angle θ with respect to the second central axis C2, selected from a range of 20° to 50°. In this embodiment, the predetermined angle θ is 30°. As shown in Figure 3(a), each of the first central axes C1a to C1f and the second central axis C2 are converged at a single point.

[0052] Furthermore, the first central axes C1a to C1f of the first transducers 52a to 52f are arranged at equal intervals in the azimuthal direction, as shown in Figure 4(a), so that the angles between adjacent first central axes C1a to C1f are the same angle δ when viewed vertically from above the ship 71 with the transmitting and receiving unit 50 attached to the ship 71. When there are n first transducers 52, the angle δ is (360 / n)° (when there are 6 first transducers 52, the angle δ is 60°).

[0053] As a result, the transmitting and receiving unit 50 can simultaneously transmit ultrasonic waves TB in each predetermined direction indicated by the first central axis 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 those predetermined directions.

[0054] In this embodiment, as shown in Figures 4(a) and (b), when viewing the ship 71 from above in a vertical direction, the first central axis C1a is oriented to the right with respect to the front-to-back direction of the ship 71, and the first central axes C1b to C1f are arranged in order counterclockwise from the first central axis C1a at intervals of angle δ. In this embodiment, an example is shown in which the first transducers 52a to 52f are arranged so that their respective first central axes C1a to C1f are evenly spaced in the azimuthal direction. However, it is sufficient that the ultrasonic TB can be transmitted simultaneously by at least the first transducers 52a to 52f in each predetermined direction indicated by the first central axes C1a to C1f over a predetermined range set in all directions of the ship 71, and there may be variations in the spacing of the first central axes C1a to C1f.

[0055] The directional characteristics of the ultrasonic TB transmitted from each of the first transducers 52a to 52f are set to include the first central axes C1a to C1f of adjacent first transducers 52. For example, as shown in Figure 4(c), the directional characteristics of the ultrasonic 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 TB transmitted from the first transducer 52b and the directional characteristics of the ultrasonic TB transmitted from the first transducer 52f are set to include the first central axis C1a of the first transducer 52a. Although not shown in the figures, the directional characteristics of the ultrasonic TB transmitted from the first transducer 52b are also set to include the first central axis C1c of the first transducer 52c adjacent on the opposite side from the first transducer 52a, and the directional characteristics of the ultrasonic TB transmitted from the first transducer 52f are also set to include the first central axis C1e of the first transducer 52e adjacent on the opposite side from the first transducer 52a.

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

[0058] As described above, the ultrasonic TB transmitted from each of the first transducers 52a to 52f is set to have directional characteristics that include the first central axes C1a to C1f of adjacent first transducers 52, and also include the vertical direction when the transmitting / receiving unit 50 is attached to the ship 71. As a result, the transmitting / receiving unit 50 drives each of the first transducers 52a to 52f simultaneously, so that ultrasonic TB is irradiated from each of the first transducers 52a to 52f in the direction of their respective first central axes C1a to C1f, and the directional characteristics of the ultrasonic TB allow the ultrasonic TB to be transmitted simultaneously to a predetermined range set in all directions of the ship 71 with a small number of first transducers 52.

[0059] Furthermore, each of the first transducers 52a to 52f has a fixed direction of the first central axis C1a to C1f and a fixed directional characteristic of the ultrasonic TB emitted from each of the first transducers 52a to 52f, so that ultrasonic TB is irradiated from the transmitting / receiving unit 50 over a predetermined range. Therefore, circuits for controlling the direction of the first central axis C1a to C1f in the first transducers 52a to 52f, and circuits for controlling the directional characteristic of the ultrasonic TB emitted from each of the first transducers 52a to 52f, can be eliminated.

[0060] Furthermore, the transmitting and receiving unit 50 can receive the reflected waves of ultrasonic waves TB reflected from the object GF to be detected within a predetermined range, for each of the first central axes C1a to C1f, which are in a predetermined direction, using the first transducers 52a to 52f corresponding to each of the first central axes C1a to C1f. As a result, the ultrasonic sonar device 1 can be constructed to perform high-speed detection in a compact and low-cost manner.

[0061] The transmitting and receiving unit 50 is arranged and housed in a case 51 with the first transducers 52a to 52f and the second transducer 53 closely packed together, such that the first central axes C1a to C1f and the second central axis C2 are oriented in the directions described above, and are fixed in place with a filler. The filler used is a resin material (for example, urethane resin) that has a lower inherent acoustic impedance than the base material 54, which is the acoustic matching layer of the first transducer 52 and the second transducer 53, and is waterproof. The outer surface of the filler is filled so that it 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 Figure 5. Figure 5 is a block diagram showing the electrical configuration of the ultrasonic sonar device 1. Inside the main body 5 of the ultrasonic sonar device 1 is a control device 10, which is equipped with transmitting units 11a, 11b, diodes 12a to 12g, receiving units 13a to 13g, a filter 14, a first detection result image generation means 15, a second detection result image generation means 16, a third detection result image generation means 17, and a display control means 18.

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

[0064] Although not shown in the diagram, the control device 10 includes a CPU (Central Processing Unit), a flash memory (a rewritable, non-volatile memory) and / or a ROM (Read Only Memory) (a non-rewritable, non-volatile memory) that stores programs executed by the CPU and fixed values ​​referenced by those programs, and a RAM (Random Access Memory) (a read-write, volatile memory) that temporarily stores various data when the CPU executes a program. These are connected via a bus line.

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

[0066] Based on instructions from the CPU, the transmitting unit 11a generates a single drive signal to transmit ultrasonic TB from the first transducers 52a to 52f. The output of the single drive signal generated by the transmitting unit 11a is branched between the transmitting unit 11a and diodes 12a to 12f and distributed to each of the first transducers 52a to 52f. Specifically, one branch is input to the first transducer 52a via diode 12a, one via diode 12b to the first transducer 52b, one via diode 12c to the first transducer 52c, one via diode 12d to the first transducer 52d, one via diode 12e to the first transducer 52e, and one via diode 12f to the first transducer 52f.

[0067] Diodes 12a to 12f each allow the drive signal generated by the transmitting unit 11a to pass through and input to the corresponding first oscillators 52a to 52f, and are also elements that block the signal (voltage) generated by receiving the reflected wave in each of the first oscillators 52a to 52f from being transmitted to the transmitting unit 11a or to the branching point of the drive signal output from the transmitting unit 11a to each of the first oscillators 52a to 52f.

[0068] A single drive signal generated by the transmitting unit 11a is branched and input to the first transducers 52a to 52f via diodes 12a to 12f. As a result, each of the first transducers 52a to 52f, which have the same shape and size, are driven simultaneously and can output ultrasonic TB of the same intensity at the same timing. Therefore, ultrasonic TB can be transmitted uniformly in a predetermined direction (i.e., the direction of the first central axis C1a to C1f) within a predetermined range set in all directions relative to the ship 71, making the detection sensitivity uniform in all predetermined directions.

[0069] Furthermore, since one transmitting unit 11a is provided for multiple first transducers 52a to 52f, significant cost reduction and miniaturization can be achieved compared to the case where each first transducer 52a to 52f has its own transmitting unit 11a.

[0070] Furthermore, diodes 12a to 12f are provided at the downstream side of the branching point between the transmitting unit 11a and each of the first transducers 52a to 52f, where the drive signal output from the transmitting unit 11a branches out toward each of the first transducers 52a to 52f. This prevents the signals (voltages) output by each of the first transducers 52a to 52f upon receiving the reflected waves of the ultrasonic TB from flowing back to the transmitting unit 11a or from interfering with the signal lines of other first transducers 52a to 52f via the branching point. Therefore, even if one transmitting unit 11a is provided for multiple (six) first transducers 52a to 52f, the independence of the signals (voltages) output from each of the first transducers 52a to 52f can be ensured.

[0071] The transmitting unit 11b generates a drive signal to transmit ultrasonic TB from the second transducer 53 based on instructions from the CPU. The output of the drive signal generated by the transmitting unit 11b is input to the second transducer 53 via the diode 12g. The diode 12g is an element that allows the drive signal generated by the transmitting unit 11b to pass through and input to the second transducer 53, and also blocks the signal (voltage) generated when the second transducer 53 receives the reflected wave from being transmitted to the transmitting unit 11b. This diode 12g prevents the signal (voltage) output by the second transducer 53 when it receives the reflected wave of ultrasonic TB from flowing back to the transmitting unit 11b.

[0072] The ultrasonic sonar device 1 is provided with a transmitting unit 11b that generates a drive signal for the second transducer 53, which transmits ultrasonic TB in the vertical direction directly below the ship 71, independently of the transmitting 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 TB from the first transducers 52a to 52f and transmitting ultrasonic TB only from the second transducer 53, or to control the transmission of ultrasonic TB from the second transducer 53 independently of the transmission of ultrasonic TB from the first transducers 52a to 52f when performing horizontal detection as a sonar function.

[0073] In this embodiment, a transmitting unit 11a corresponding to the first transducers 52a to 52f and a transmitting unit 11b corresponding to the second transducer 53 are provided separately. However, if the specifications of the ultrasonic sonar device 1 allow for the transmission of ultrasonic TB from the second transducer 53 to always occur at the same timing as the first transducers 52a to 52f, then only one transmitting unit 11a may be provided for the first transducers 52a to 52f and the second transducer 53, and a single drive signal may be generated from this transmitting unit 11a. This would allow for further significant cost reduction and miniaturization of the ultrasonic sonar device 1.

[0074] Receiving units 13a to 13g are provided for each of the multiple (6) first transducers 52a to 52f and second transducer 53. The corresponding first transducers 52a to 52f and second transducer 53 receive the reflected waves of the ultrasonic TB, and the receiving units capture a signal (voltage) output according to the intensity of the reflected waves, and perform predetermined processing on the captured signal.

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

[0076] Each receiving unit 13a to 13g has an amplification circuit and an analog-to-digital conversion circuit. As a predetermined process, the received signal (voltage) is amplified by the amplification 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 the digital signal obtained by the AD conversion circuit to the filter 14 as the received signal (received signal of the reflected wave of the ultrasonic TB) received by the first transducer 52a. Similarly, the receiving unit 13b outputs the digital signal obtained by the respective AD conversion circuit to the filter 14 as the received signal of the first transducer 52b, the receiving unit 13c outputs the digital signal obtained by the first transducer 52c, the receiving unit 13d outputs the digital signal obtained by the first transducer 52d, the receiving unit 13e outputs the digital signal obtained by the first transducer 52e, the receiving unit 13f outputs the digital signal obtained by the first transducer 52f, and the receiving unit 13g second transducer 53.

[0078] As described above, one transmitting unit 11a is provided for each of the multiple (six) first transducers 52a to 52f to reduce costs and miniaturize the device. In contrast, by providing a receiving unit 13a to 13f for each of the multiple first transducers 52a to 52f, the independence of the signals (voltages) output from each of the first transducers 52a to 52f can be maintained while applying predetermined processing to each signal (voltage). On the other hand, since the ultrasonic sonar device 1 has fewer transducers than conventional scanning sonars, even if a receiving unit 13a to 13f is provided for each of the first transducers 52a to 52f, the overall receiving unit can be made smaller and costs can be reduced compared to conventional scanning sonars.

[0079] The received signals output from the receiving units 13a to 13g are original received signals that represent the raw intensity values ​​of the reflected ultrasonic TB waves received by the corresponding first transducers 52a to 52f and the second transducer 53, respectively. This means that the original received signals are the received signals before filtering by the filter 14, which will be described next.

[0080] The filter 14 performs a predetermined filtering process on the received signals (original received signals) output from the receiving units 13a to 13g for each of the first oscillators 52a to 52f and the second oscillator 53. The predetermined filtering process may include spatial filtering and / or temporal filtering.

[0081] As for spatial filtering, for the purpose of reducing noise and / or improving resolution, filtering is performed in the azimuth and distance directions on the original received signals of each first transducer 52a to first transducer 52f that have received reflected ultrasonic TB waves for each predetermined direction. Furthermore, spatial filtering also includes filtering in the distance direction on the original received signal of the second transducer 53 that has received reflected ultrasonic TB waves 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 transducers 52a to 52f, that is, the direction in which their respective acoustic radiation directions are aligned, or in other words, the circumferential direction centered on the ship 71. The distance direction is the direction in which the ultrasonic TB is transmitted at the first central axes C1a to C1f of the first transducers 52a to 52f, and at the second central axis C2 of the second transducer 53, that is, the respective acoustic radiation directions themselves.

[0083] Furthermore, when the ultrasonic sonar device 1 performs horizontal detection using its sonar function, it uses a small number of transducers (six in this embodiment), namely the first transducers 52a to 52f, which significantly reduces the azimuth resolution. Therefore, in horizontal detection, the filter 14 sets a virtual direction at an intermediate position between adjacent first central axes C1a to C1f of the first transducers 52a to 52f, which are predetermined directions in which ultrasonic TB is transmitted and received. The filter then generates a received signal from the received signals of the first transducers 52a to 52f, assuming that ultrasonic TB was virtually transmitted and received in that virtual direction.

[0084] By generating a virtual received signal in a virtual direction, the number of directions in which ultrasonic TB is transmitted and received, including the virtual direction, can be double the actual number of first transducers 52 (12 directions in this embodiment), thereby improving the azimuth resolution.

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

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

[0087] The first detection result image generation 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 generation 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 horizontal detection is performed. The third detection result image generation 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 horizontal detection is performed.

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

[0090] The first detection result image 22 is a commonly known detection result image for horizontal detection, and displays the latest detection results for each direction in a circular detection result image for omnidirectional detection of the ship 71. Specifically, based on the received 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 virtual received signals for each direction virtually set between those directions, the latest detection results over a predetermined range set for omnidirectional detection of the ship 71 are displayed on the display device 21 as the first detection result image 22.

[0091] The first detection result image generation means 15 generates a first detection result image 22 using the filtered received signals from the first transducers 52a to 52f, which are input from the filter 14, and virtual received signals for each virtually set direction. The user can determine the current direction of the detected object GF relative 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 a time-series arrangement of the detection results for the first range, similar to a fish finder, based on the received signals from the first transducers 52a to 52f that have the first central axes C1a to C1f included in the first range, within a predetermined range set in all directions relative to the ship 71.

[0093] Furthermore, the third detection result image 24 is a time-series arrangement of detection results in the second range, similar to a fish finder, based on the received signals of the first transducers 52a to 52f that have the first central axes C1a to C1f included in the second range, which is a predetermined direction included in the second range, which is different from the first range, among the first central axes C1a to C1f that are included in the second range.

[0094] The first detection result image 22 only includes the detection result at a certain point in time for at least each predetermined direction (first central axis C1a to C1f), so there is a risk of frequently overlooking the target object GF. In response to this, a second detection result image 23 is generated by the second detection result image generation means 16, which arranges the detection results of the first range in chronological order based on the received signals of a predetermined direction included in the first range of the predetermined range, and is displayed on the display device 21. Furthermore, a third detection result image 24 is generated by the third detection result image generation means 17, which arranges the detection results of the second range in chronological order based on the received signals of a predetermined direction included in the second range of the predetermined range, and is displayed on the display device 21.

[0095] As a result, the detection history of objects GF present in the first range is recorded in the second detection result image 23, and the detection history of objects GF present in the second range is recorded in the third detection result image 24. Therefore, it is possible to suppress the oversight of objects GF that would be easily missed if only the first detection result image 22 were used. 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 suppress the oversight of objects GF while making it easier to understand which ranges objects GF have been present in, including in the past.

[0096] The first range may be set to, for example, the half range on the starboard side of the vessel 71 out of all bearings relative to the vessel 71, and the second range may be set to the half range on the port side of the vessel 71 out of all bearings relative to the vessel 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 Figure 4(a)).

[0097] Therefore, in this case, the second detection result image generation means 16 synthesizes the received signals from the first transducers 52b, 52a, and 52f for each depth to generate one detection result line, and arranges them in chronological order so that the oldest detection result line is on the right and the newest detection result line is on the left, thereby generating a second detection result image 23 that is equivalent to the detection result image of a fish finder. Furthermore, the third detection result image generation means 17 synthesizes the received signals from the first transducers 52c, 52d, and 52e for each depth to generate one detection result line, and arranges them in chronological order so that the oldest detection result line is on the right and the newest detection result line is on the left, thereby generating a third detection result image 24 that is equivalent to the detection result image of a fish finder.

[0098] As a result, the second detection result image 23 retains the detection history of object GF that was located within the range of the starboard side of the vessel 71, and the third detection result image 24 retains the detection history of object GF that was located within the range of the port side of the vessel 71. Therefore, it is easy to determine whether object GF was located on the starboard side or the port side of the vessel 71, including in the past.

[0099] Furthermore, the first range may be set to the forward half of the range of all directions relative to the vessel 71, and the second range may be set to the aft half of the range of all directions relative to the vessel 71. In this case, the predetermined directions included in the first range are the first central axes C1b and C1c, and the predetermined directions included in the second range are the first central axes C1e and C1f (see Figure 4(a)).

[0100] Therefore, in this case, the second detection result image generation means 16 synthesizes the received signals from the first transducers 52b and 52c for each depth to generate one detection result line, 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, thereby generating a second detection result image 23 that is equivalent to the detection result image of the fish finder. Furthermore, the third detection result image generation means 17 synthesizes the received signals from the first transducers 52e and 52f for each depth to generate one detection result line, 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, thereby generating a third detection result image 24 that is equivalent to the detection result image of the fish finder.

[0101] As a result, the second detection result image 23 retains the detection history of object GF that was located in the forward area of ​​the vessel 71, and the third detection result image 24 retains the detection history of object GF that was located in the rear area of ​​the vessel 71. This makes it easy to determine whether object GF was located in the forward area of ​​the vessel 71 or in the rear area, including in the past.

[0102] In this case, the predetermined directions included in the first range may be defined as the first central axes C1a, C1b, C1c, and C1d, and the second detection result image 23 may be generated using the received signals of the first transducers 52a, 52b, 52c, and 52d. Alternatively, the predetermined directions included in the second range may be defined as the first central axes C1d, C1e, C1f, and C1a, and the third detection result image 24 may be generated using the received signals of the first transducers 52d, 52e, 52f, and 52a. In this case, the received signals of the first transducers 52a and 52d may be included in either the second detection result image 23 or the third detection result image 24, or the received signals of the first transducers 52a and 52d may be included in either the second detection result image 23 or the third detection result image 24. These features allow the detection results from all directions in which the reflected waves of the ultrasonic TB are received to be included in at least one of the second detection result image 23 and the third detection result image 24.

[0103] Furthermore, the first range may be set to encompass all directions relative to the vessel 71, and may be a predetermined direction in which all 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 generation means 16 synthesizes the received signals from all first transducers 52a to 52f for each depth to generate one detection result line, 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, thereby generating a second detection result image 23 that is equivalent to the detection result image of a fish finder.

[0104] As a result, the detection history of the target object GF that was present within the detection range (i.e., a predetermined range) of the detection result shown in the first detection result image 22 is recorded in the second detection result image 23, thereby suppressing the oversight of target objects GF within that predetermined range.

[0105] Furthermore, if the first range is set to all directions relative to the ship 71, the second detection result image generation means 16 may synthesize the received signals from all the first transducers 52a to 52f, as well as the received signal from the second transducer 53, for each depth to generate a single detection result line, and generate a second detection result image 23 that is equivalent to the detection result image of a fish finder. The received signals from the first transducers 52a to 52f also include the detection results in the vertical direction directly below the ship 71, but by including the received signal from the second transducer 53 in the generation of the second detection result image 23, the vertical detection results can be reflected in the second detection result image 23 with high sensitivity.

[0106] Furthermore, if the first range is set to all directions relative to the vessel 71, the third detection result image generation means 17 may not generate the third detection result image 24 and may hide the third detection result image 24 on the display device 21. Alternatively, the third detection result image generation means 17 may generate a detection result image of the vertical direction directly below the vessel 71 as the third detection result image 24 based on the received signal from the second transducer 53, and display the third detection result image 24 on the display device 21. In the latter case, the user can, through the third detection result image 24, determine the presence or absence of a detected object GF in the vertical direction directly below the vessel 71, going back in time.

[0107] Furthermore, when the ultrasonic sonar device 1 is set to include the detection results of the second transducer 53 in the second detection result image 23, if the first range shown in the second detection result image 23 is set to cover all directions relative to the vessel 71, the user may set whether or not to include the detection results of the second transducer 53 in the second detection result image 23. Also, when the ultrasonic sonar device 1 is set to include the first range shown in the second detection result image 23 is set to cover all directions relative to the vessel 71, the user may set whether or not to display the third detection result image 24 as the detection result in the vertical direction directly below the vessel 71.

[0108] Furthermore, the ultrasonic sonar device 1 may allow the user to set whether the first range shown in the second detection result image 23 and the second range shown in the third detection result image 24 are on the starboard / port side of the vessel 71, or on the forward / stern side of the vessel 71, or whether the first range shown in the second detection result image 23 is omnidirectional relative to the vessel 71.

[0109] The display control means 18 controls the display device 21 to display the first detection result image 22 generated by the first detection result image generation means 15, the second detection result image 23 generated by the second detection result image generation means 16, and the third detection result image 24 generated by the third detection result image generation means 17. For example, the display control means 18 adjusts the size and display position 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 a single image on the display device 21.

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

[0111] When the user turns on the power to the ultrasonic sonar device 1 via the operation button 31, or when the user is instructed to start horizontal detection using the sonar function while the power is on, the ultrasonic sonar device 1 first drives the lifting device 41 to bring the transmitting and receiving unit 50 out of the water from the bottom of the ship 71.

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

[0113] The ultrasonic TB transmitted from the first transducers 52a to 52f and the second transducer 53 is reflected from the detection target object GF, seabed SB, etc., that are present in a predetermined range from which the ultrasonic TB is transmitted. The reflected waves are received by the first transducers 52a to 52f and the second transducer 53, and signals (voltages) are output from the first transducers 52a to 52f and the second transducer 53 as the intensity of the reflected waves received in each direction of the first central axis C1a to C1f and the second central axis C2, respectively.

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

[0115] These original received signals are subjected to spatial (and temporal) filtering by filter 14. Furthermore, filter 14 sets a virtual direction for each of the first central axes C1a to C1f at a position midway between adjacent first central axes C1a to C1f, and generates received signals from the respective received signals of the first transducers 52a to 52f, assuming that ultrasonic TB was virtually transmitted and received in that virtual direction.

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

[0117] Then, for the omnidirectional detection of the vessel 71, a first detection result image 22 is generated by the first detection result image generation means 15, which displays the latest detection results for each direction as a circular detection result image. Furthermore, based on the received signals in a predetermined direction included in the first range within a predetermined range set omnidirectionally for the vessel 71, a second detection result image 23 is generated by the second detection result image generation means 16, which arranges the detection results of the first range in chronological order, similar to a fish finder. Furthermore, based on the received signals in a predetermined direction included in the second range within a predetermined range set omnidirectionally for the vessel 71, a third detection result image 24 is generated by the third detection result image generation means 17, which arranges the detection results of the second range in chronological order, similar to a fish finder.

[0118] These first detection result images 22, second detection result images 23, and third detection result images 24 are displayed on the display device 21 by the display control means 18, as shown in Figure 6.

[0119] Now, with reference to Figure 7, the method for generating the second detection result image 23 in the second detection result image generation means 16 will be explained. Figure 7 is a flowchart showing the second detection result image generation process performed by the second detection result image generation means 16. Note that the method for generating the third detection result image 24 in the third detection result image generation means 17 is simply the same as the method for generating the second detection result image 23 in the second detection result image generation means 16, but with the first range replaced by the second range, so its explanation will be omitted.

[0120] When the second detection result image generation means 16 receives received signals from the filter 14 in the directions of the first central axis C1a to C1f and the second central axis C2 after filtering, it starts the execution of the second detection result image generation process. When the second detection result image generation means 16 starts the execution of the second detection result image generation process, it first identifies the first range (S1). The first range is set to either the starboard side, the forward side, or all directions of the vessel 71. In the third detection result image generation process, the second range is set to either the port side, the aft side, or the vertical direction directly below the vessel 71.

[0121] Next, the second detection result image generation means 16 identifies a predetermined direction included in the first range identified in the processing of S1 from among the first central axes C1a to C1f (S2). For example, if the starboard side of the ship 71 is identified as the first range, the first central axes C1b, C1a, and C1f are identified as predetermined directions included in the first range. Also, if the forward 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 predetermined directions included in the first range. Also, if all directions relative 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 predetermined directions included in the first range.

[0122] In the third detection result image generation process, if the port side of the vessel 71 is specified as the second range, the first central axes C1c, C1d, and C1e are specified as predetermined directions included in the second range. If the aft side of the vessel 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 predetermined directions included in the second range. If the vertical direction directly below the vessel 71 is specified as the second range, the second central axis C2 is specified as predetermined directions included in the first range.

[0123] Next, the second detection result image generation means 16 sets the variable i to 0 (S3). The variable i is a variable that represents the depth position. When the variable i is 0, it indicates the shallowest depth among the received signals in each predetermined direction. As the value of the variable i increases, it indicates a deeper depth. When the variable i is at its maximum value, imax, it indicates the deepest depth among the received signals in each predetermined direction. Subsequent processing is performed for all received signals at all depths, increasing the variable i by 1 each time.

[0124] Specifically, the second detection result image generation means 16 acquires received signals of depths specified by variable i in all predetermined directions included in the first range identified in S2 (S4). Then, the second detection result image generation means 16 combines the received signals of depths specified by variable i in all predetermined directions included in the first range into one by selecting the maximum level among the received signals of depths specified by variable i acquired by the processing in S4 (S5).

[0125] Next, the second detection result image generation means 16 adds 1 to the variable i to advance the depth to which processing in S4 and S5 is to be performed (S6). Then, the second detection result image generation means 16 determines whether the variable i after processing in S6 (after addition) is greater than the maximum value imax (S7). If the variable i is less than or equal to the maximum value imax (S7: No), it performs processing in S4 and S5 on the received signal at the depth specified by the variable i after addition. In other words, processing in S4 and S5 is performed on all 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, the received signals from each predetermined direction included in the first range are combined into one.

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

[0127] In the process of S2, if there is only one predetermined direction included in the first range (for example, in the second range, only the second central axis C2 may be the predetermined direction. Also, depending on the setting ranges of the first and second ranges and the arrangement of the first transducers 52a to 52f, there may be cases where both the first and second ranges contain only one predetermined direction), there is no need to synthesize the received signals from each predetermined direction, so the processes of S3 to S7 may be skipped and the process may proceed from S2 to S8. In this case, the process of S8 generates the detection result line directly from the received signal 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 such that the oldest detection result line is on the right and the newest detection result line is on the left, thereby generating a second detection result image 23 that is equivalent to the detection result image of the fish finder (S9), and ends the second detection result image generation process.

[0129] With the ultrasonic sonar device 1 configured as described above, the transmitting and receiving unit 50 transmits ultrasonic TB into the water from the first transducers 52a to 52f and the second transducer 53 in all directions relative to the vessel 71 set within a predetermined range. Then, for each predetermined direction, the first central axis C1a to C1f and the second central axis C2, the reflected waves of ultrasonic TB reflected from each position in the water are received by the first transducers 52a to 52f and the second transducer 53 of the transmitting and receiving unit 50. Based on the reflected waves received by the transmitting and receiving unit 50, a received signal is generated for each predetermined direction by the receiving units 13a to 13g and the filter 14.

[0130] Based on the received signals generated for each predetermined direction, the first detection result image generation means 15 generates a first detection result image 22 showing the latest detection results over a predetermined range. From this first detection result image 22, it is possible to determine at least whether or not there is a target object GF in the predetermined range and the direction in which the target object GF is currently located.

[0131] Meanwhile, based on the received signals in a predetermined direction included in the first range within a predetermined range, the second detection result image 23 is generated by the second detection result image generation means 16, which arranges the detection results of the first range in chronological order. As a result, the history of the detection results of the target object GF that was present in the first range is recorded in the second detection result image 23. Therefore, it is possible to suppress the oversight of the target object GF.

[0132] Furthermore, based on the received signals in a predetermined direction included in a second range different from the first range within a predetermined range, a third detection result image 24 is generated by the third detection result image generation means 17, which arranges the detection results of the second range in chronological order. As a result, not only is the history of detection results of objects GF present in the first range preserved in the second detection result image 23, but the history of detection results of objects GF present in the second range is also preserved in the third detection result image 24. Therefore, it is possible to suppress the oversight of objects GF while making it easier to understand which ranges objects GF have been present in, including in the past.

[0133] Furthermore, if the first range and / or second range includes a plurality of predetermined directions, the received signals for each of those predetermined directions are combined, and based on the combined received signals, the second detection result image generation means 16 generates the second detection result image 23, and the third detection result image generation means 17 generates the third detection result image 24. Therefore, the detection results of the object GF to be detected based on the transmission and reception of ultrasonic TB performed for each of the plurality of predetermined directions included in the first range and / or second range are all included in the second detection result image 23 or the third detection result image 24, and furthermore, the history of the detection results is recorded in the second detection result image 23 or the third detection result image 24, so that the oversight of the object GF to be detected can be more reliably suppressed.

[0134] Furthermore, the synthesis of received signals performed by the second detection result image generation means 16 or the third detection result image generation means 17 is carried out by selecting the maximum level among the levels of multiple received signals to be synthesized for each depth. This ensures that reflected waves with high reflection intensity, which are likely to be detected objects GF, are reliably represented in the second detection result image 23 or the third detection result image 24. Thus, the oversight of detected objects GF can be more reliably suppressed.

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

[0136] Although the present invention has been described above based on embodiments, it is easy to infer that the present invention is not limited in any way to the above embodiments, and that various improvements and modifications are possible without departing from the spirit of the present invention. For example, each embodiment may be modified by adding or replacing some or more parts of the configuration of other embodiments with parts or more parts of the configuration of other embodiments, including the modifications described below. Furthermore, the numerical values ​​given in the above embodiments are merely examples, and it is naturally possible to use other numerical values.

[0137] In the above embodiment, the case in which the transmitter / receiver unit 50 is equipped with a second transducer 53 whose second central axis C2 is in the vertical direction directly below the ship 71 was described. However, at least when performing horizontal detection as a sonar function, detection in the vertical direction directly below the ship 71 may not always be necessary. Also, in the above embodiment, since the directional characteristics of the ultrasonic TB transmitted from the first transducers 52a to 52f include the vertical direction directly below the ship 71, it is possible to detect an object GF located in the vertical direction directly below the ship 71 using only the first transducers 52a to 52f, although the detection sensitivity and / or accuracy will decrease. Therefore, the second transducer 53 may be omitted from the transmitter / receiver unit 50.

[0138] In the above embodiment, the case in which the first transducers 52a to 52f are inclined to face inward (towards the side where the second transducer 53 is located) has been described. However, the invention is not limited to this, and the first transducers 52a to 52f may also be inclined to face outward (towards the side opposite to the side where the second transducer 53 is located) with respect to each other. In this case as well, it is preferable that the first central axes C1a to C1f each form a predetermined angle θ with respect to the second central axis C2 (the vertical direction when the transmitting / receiving unit 50 is attached to the ship 71), selected from a range of 20° to 50°.

[0139] In the above embodiment, the case in which the first transducers 52a to 52f are provided around the second transducer 53 in the transmitting and receiving unit 50 was described. However, the arrangement of the first transducers 52a to 52f and the second transducer 53 in the transmitting and receiving unit 50 can be arbitrary, as long as, when the 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 make 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 or two rows, or the first oscillators 52a to 52f may be arranged in two rows and the second oscillator 53 may be placed at any position between the two rows of the first oscillators 52a to 52f.

[0140] In the above embodiment, the case in which detection is performed over a predetermined range set in all directions of the vessel 71 was described. However, the predetermined range may be a predetermined range set for a part of the direction of the vessel 71. In this case as well, the first range may be set to a part or all of the predetermined range. Furthermore, the second range may be set to a part or all of the predetermined range, insofar as it differs from the first range.

[0141] In the above embodiment, a case was described in which the number of first transducers 52 in the transmitting / receiving unit 50 is reduced, and ultrasonic TB is transmitted and received simultaneously from the first transducers 52 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, is also applicable to detection using PPI sonar and scanning sonar.

[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 Filter 15 First detection result image generation means 16 Second detection result image generation means 17 Third detection result image generation means 18 Display control means 21 Display device 22 First detection result image 23 Second detection result image 24 Third detection result image 50 Transmitting and receiving unit 52 First transducer 52a First transducer 52b First transducer 52c First transducer 52d First transducer 52e First transducer 52f First transducer 53 Second transducer 71 Ship C1a First central axis C1b First central axis C1c First central axis C1d: First central axis; C1e: First central axis; C1f: First central axis; C2: Second central axis; GF: Object to be detected; TB: Ultrasound

Claims

1. An ultrasonic sonar device comprising: a transmitting and receiving unit capable of transmitting ultrasonic waves over a predetermined range in water and receiving reflected ultrasonic waves reflected from each position in the water for each predetermined direction; a receiving signal generation means that generates a received signal for each predetermined direction based on the reflected waves received by the transmitting and receiving unit; a first detection result image generation means that generates a first detection result image showing the latest detection results over the predetermined range based on the received signals for each predetermined direction generated by the receiving signal generation means; and a second detection result image generation means that 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 the predetermined direction included in the first range within the predetermined range.

2. The ultrasonic sonar device according to claim 1, wherein the second detection result image generation means synthesizes the received signals for each of the plurality of predetermined directions when the first range includes a plurality of predetermined directions, and generates a second detection result image based on the synthesized received signals.

3. The ultrasonic sonar apparatus according to claim 2, characterized in that the synthesis of the received signals is performed by selecting the maximum level from among the levels of a plurality of received signals to be synthesized for each depth.

4. The ultrasonic sonar device according to claim 1, characterized in that the first range is the same as the predetermined range.

5. The ultrasonic sonar device according to claim 1, further comprising a third detection result image generation 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 predetermined direction that is included in the second range which is different from the first range among the predetermined ranges.

6. The ultrasonic sonar device according to claim 5, characterized in that the first range covers the starboard side of the vessel on which the transmitting and receiving unit is installed, and the second range covers the port side of the vessel.

7. The ultrasonic sonar device according to claim 5, characterized in that the first range extends to the front side of the vessel on which the transmitting and receiving unit is installed, and the second range extends to the rear side of the vessel.

8. The ultrasonic sonar device according to claim 1, wherein the transmitting and receiving unit comprises a plurality of first transducers having predetermined directional characteristics, and each of the plurality of first transducers is fixed such that its central axis is in the predetermined direction and, when the transmitting and receiving unit is attached to a ship, its central axis is positioned at a predetermined angle with respect to the vertical direction, and has predetermined directional characteristics that include at least the central axis of an adjacent first transducer and the vertical direction.

9. The ultrasonic sonar device according to claim 8, wherein the transmitting and receiving unit further comprises a second transducer fixed such that its central axis is positioned vertically when attached to a ship.

10. The ultrasonic sonar device according to claim 8, comprising: a transmitting unit that simultaneously drives a plurality of first transducers by distributing a drive signal for transmitting the ultrasonic waves from the plurality of first transducers of the transmitting and receiving unit to the plurality of first transducers via a diode; and a receiving unit provided corresponding to each of the plurality of first transducers of the transmitting and receiving unit, which receives a signal output when the corresponding first transducer receives the reflected wave and performs predetermined processing.

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