Ultrasonic sonar device

Abstract

An ultrasonic sonar device comprises: a plurality of first vibrators 52a-52f; and a second vibrator 53 that is fixed so as to allow the second central axis to be positioned in the vertical direction. Each of the first vibrators 52a-52f is fixed so as to have the first central axis to be positioned at a prescribed angle with respect to the vertical direction, and has prescribed directional characteristics that include the first central axis of at least the adjacent first vibrator 52a-52f and the vertical direction. When performing underwater detection over a prescribed range, transmission units 11a, 11b either turn off the transmission of ultrasonic waves from the second vibrator 53, or set the intensity of ultrasonic waves to be transmitted from the second vibrator 53 to be lower than the intensity of ultrasonic waves TB to be transmitted from the first vibrators 52a-52f.

Description

Ultrasonic Sonar Device

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

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

[0003] The PPI sonar is configured such that a vibrator that irradiates (transmits) a thin beam-shaped ultrasonic wave and receives a reflected wave from the detection target or the like of the ultrasonic wave can rotate or pivot, 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 a low cost, but it takes time to complete one detection over a predetermined range.

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

[0005] Japanese Unexamined Patent Application Publication No. 2019-066208, Japanese Unexamined Patent Application Publication No. 2019-200204

[0006] Regarding such a conventional ultrasonic sonar device, the inventor has invented an ultrasonic sonar device that can realize high-speed detection at a low cost by transmitting ultrasonic waves simultaneously over a predetermined range and receiving the reflected waves with a small number of vibrators for further popularization of the ultrasonic sonar device. However, further improvement is required to put this into the market as a product.

[0007] This invention has been made in view of the above circumstances, and aims to provide an ultrasonic sonar device that can achieve high-speed detection at low cost and can suppress the detection target from being obscured by reflected waves from the bottom of the sea in the vertical direction.

[0008] To achieve this objective, a first aspect of the present invention provides an ultrasonic sonar device comprising: a transmitter / receiver unit capable of transmitting ultrasonic waves over a predetermined range in water and receiving reflected ultrasonic waves reflected from each position in the water in a predetermined direction; an ultrasonic transmission drive means for driving the transmission of ultrasonic waves from the transmitter / receiver unit; a receiving signal generation means for generating received signals for each predetermined direction based on the reflected waves received by the transmitter / receiver unit; and a detection result image generation means for generating a detection result image showing the latest detection result over the predetermined range based on the received signals for each predetermined direction generated by the receiving signal generation means, wherein the transmitter / receiver unit comprises a plurality of first transducers having predetermined directional characteristics with respect to a central axis, The ultrasonic transmitting drive means includes a second transducer fixed such that its central axis is positioned vertically when the transmitting unit is attached to a ship, wherein each of the plurality of first transducers is fixed such that its central axis is in the predetermined direction and is positioned at a predetermined angle with respect to the vertical when the transmitting unit is attached to a ship, and has predetermined directional characteristics that include at least the central axis of an adjacent first transducer and the vertical direction, and the ultrasonic transmitting drive means turns off the transmission of ultrasonic waves from the second transducer or makes the intensity of ultrasonic waves transmitted from the second transducer less than the intensity of ultrasonic waves transmitted from the first transducer when performing underwater detection over the predetermined range.

[0009] A second aspect of the present invention is an ultrasonic sonar device according to the first aspect, comprising a seabed depth determination means for determining the vertical depth of the seabed of a vessel on which the transmitting and receiving unit is installed, based on the intensity of the reflected waves received by the transmitting and receiving unit, and the detection result image generation means for drawing predetermined marks on the detection result image at the positions of the seabed depth determined by the seabed depth determination means.

[0010] A third aspect of the present invention is an ultrasonic sonar device according to the second aspect, wherein the seabed depth determination means determines the depth of the seabed based on the intensity of the reflected waves transmitted by the second transducer and received by the second transducer.

[0011] According to the ultrasonic sonar device of the first aspect of the present invention, a transmitting and receiving unit is driven by an ultrasonic transmitting and receiving means to transmit ultrasonic waves over a predetermined range in the water. The reflected ultrasonic waves reflected from each position in the water in each predetermined direction are received by the transmitting and receiving unit. Based on the reflected waves received by the transmitting and 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 detection result image showing the latest detection results over the predetermined range is generated by a detection result image generation means. From this detection result image, it is possible to determine whether or not there is a target object in the predetermined range and the direction in which the target object is located.

[0012] Here, multiple first transducers are fixed to the transducer unit such that their central axes are oriented in a predetermined direction, and that when the transducer unit is mounted on a ship, their central axes are positioned at a predetermined angle to the vertical. Each first transducer has predetermined directional characteristics that include at least the central axis of an adjacent first transducer and the vertical direction. This allows for simultaneous transmission of ultrasonic waves over a predetermined range using a small number of first transducers, and detection of objects by receiving the reflected waves. Thus, high-speed detection can be achieved at low cost.

[0013] Furthermore, the transmitter / receiver unit includes a second transducer in addition to the multiple first transducers. This second transducer is fixed to the transmitter / receiver unit so that its central axis is positioned vertically when the transmitter / receiver unit is mounted on a ship. By transmitting and receiving ultrasonic waves in the vertical direction using the second transducer, objects to be detected in the vertical direction can be detected with high precision.

[0014] However, since the first transducer also has directional characteristics in the vertical direction, it will receive reflected waves from the seabed in the vertical direction, transmitted by the second transducer, before it receives reflected waves from the seabed in the direction of its own central axis. If the intensity of the ultrasonic waves transmitted by the second transducer is high, the intensity of the reflected waves received by the first transducer will also be high, which may cause objects to be detected at a distance approximately equal to the vertical depth of the seabed, at an oblique direction from the vessel being detected by the first transducer, to be obscured by the reflected waves and become undetectable.

[0015] In contrast, when performing underwater detection over a predetermined range, the ultrasonic transmission drive means either turns off the transmission of ultrasonic waves from the second transducer, or reduces the intensity of the ultrasonic waves transmitted from the second transducer to less than the intensity of the ultrasonic waves transmitted from the first transducer. This eliminates the vertical reflection of the seabed caused by the ultrasonic waves transmitted from the second transducer, or reduces the intensity of the reflected waves received by the first transducer after the ultrasonic waves transmitted from the second transducer are reflected from the seabed in the vertical direction. Therefore, it is possible to suppress the obscuration of objects being detected by the first transducer that are located at a distance approximately equal to the vertical depth of the seabed at an oblique direction from the vessel being detected, making them easier to detect. Consequently, it is possible to achieve high-speed detection at low cost, and it has the effect of suppressing objects being obscured by reflected waves from the seabed in the vertical direction.

[0016] The ultrasonic sonar device according to the second embodiment provides the following effects in addition to those of the ultrasonic sonar device according to the first embodiment. Specifically, based on the intensity of the reflected waves received by the transmitting and receiving unit, the depth of the seabed in the vertical direction of the vessel on which the transmitting and receiving unit is installed is determined by the seabed depth determination means. Then, a predetermined mark is drawn on the detection result image by the detection result image generation means at the position of the seabed depth determined by the seabed depth determination means. The first transducer will receive reflected waves from the seabed in the vertical direction directly below the vessel before receiving reflected waves from the seabed in the direction of its own central axis. However, the predetermined mark attached to the detection result image has the effect of clearly indicating to the user that detection results displayed beyond the vertical seabed depth are invalid.

[0017] 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, ultrasonic waves are transmitted by a second transducer whose central axis is located in the vertical direction, and the depth of the seabed in the vertical direction of the vessel is determined by a seabed depth determination means based on the intensity of the reflected waves received by the second transducer. This allows for a more accurate determination of the depth of the seabed in the vertical direction of the vessel compared to determining the depth of the seabed in the vertical direction of the vessel using a first transducer whose central axis is located at a predetermined angle with respect to the vertical direction. Therefore, the location of the depth of the seabed in the vertical direction can be clearly indicated to the user with high accuracy by a predetermined mark attached to the detection result image.

[0018] 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 showing the electrical configuration of the ultrasonic sonar device. This is a schematic diagram illustrating the effect of ultrasound transmitted from the second transducer on the first transducer. (a) shows the case where high-intensity ultrasound is transmitted from the second transducer, and (b) shows the case where low-intensity ultrasound is transmitted from the second transducer. (a) is a flowchart showing the transmission process, and (b) is a flowchart showing the bottom guide link generation process. This is a schematic diagram showing an example of a display screen displayed on the display device of the ultrasonic sonar device.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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, and give instructions to start / stop horizontal detection using the sonar function, etc., by operating the operation button 31.

[0024] 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.

[0025] The display device 21 displays the detection result based on the received signal 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 detection result image 22, etc. Details of the detection result image 22 will be described later with reference to Figure 8.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] Furthermore, when the substrate 54 vibrates due to the reflected waves of the ultrasonic TB, the piezoelectric element 55 of each of the first transducer 52 and the second transducer 53 deforms due to the vibration, and a voltage is generated between the front electrode and the back electrode. The first transducers 52a to 52f and the second transducer 53 each output the voltage generated between the front electrode and the back electrode to the corresponding receiving units 13a to 13g, which will be described later, thereby generating a received signal corresponding to the reflected waves received by each of the first transducers 52a to 52f and the second transducer 53.

[0033] The case 51 has an opening at one end, and a plurality of first resonators 52 and second resonators 53 are housed inside the case 51. The second resonator 53 is positioned in the center of the case 51. Six first resonators 52 are arranged around the second resonator 53 in the order of first resonator 52a, first resonator 52b, first resonator 52c, first resonator 52d, first resonator 52e, and first resonator 52f, in a counterclockwise direction when viewed from the front side of the base material 54. The acoustic radiation surfaces formed on the front surface of the base material 54 of each first resonator 52 and the acoustic radiation surfaces formed on the front surface of the base material 54 of the second resonator 53 are all located on a single virtual sphere.

[0034] In this embodiment, six first transducers 52 are used, but the number of first transducers 52 may be any number of three or more, preferably four or more, and more preferably six or more. However, if the number of first transducers 52 increases, the configuration of the ultrasonic sonar device 1 becomes more complex, larger, and more expensive, so it is preferable that the number of first transducers 52 be 10 or less, and more preferably 8 or less.

[0035] Here, for the first transducer 52a, the direction of the first central axis C1a, which is a central axis perpendicular to the center of the front surface (acoustic radiation surface) of the substrate 54 (which can also be called the direction of the normal vector of the first transducer 52a), can be understood as the acoustic radiation direction. Similarly to the first transducer 52a, the first transducer 52b has a first central axis C1b, the first transducer 52c has a first central axis C1c, the first transducer 52d has a first central axis C1d, the first transducer 52e has a first central axis C1e, and the first transducer 52f has a first central axis C1f. Then, each of the first central axes C1b to C1f can be understood as the acoustic radiation direction of the corresponding first transducers 52b to 52f.

[0036] Furthermore, the direction of the second central axis C2, which is a central axis perpendicular to the center of the front surface (acoustic radiation surface) of the substrate 54 (which can also be called the direction of the normal vector of the second transducer 53), can be understood to be the acoustic radiation direction.

[0037] That is, the first central axes C1a to C1f of each of the first transducers 52a to 52f and the second central axis C2 of the second transducer 53 are in a predetermined direction for transmitting ultrasonic waves TB and receiving their reflected waves within a predetermined range which is the detection range of the object GF to be detected.

[0038] Here, the transmitting and receiving unit 50 is mounted on the ship 71 such that the direction of the second central axis C2 of the second transducer 53 is vertical. That is, the second transducer 53 transmits (irradiates) ultrasonic TB in the vertical direction directly below the ship 71. Due to the presence of this second transducer 53, the ultrasonic sonar device 1 can detect objects GF in the vertical direction with high accuracy. It is preferable that the directional characteristics of the ultrasonic TB transmitted from the second transducer 53 be such that its directional angle is small and it forms a narrow beam. This further improves the accuracy of detecting objects GF in the vertical direction.

[0039] 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).

[0040] 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.

[0041] 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°).

[0042] 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.

[0043] In this embodiment, as shown in FIGS. 4(a) and 4(b), when the ship 71 is viewed vertically from above, the first central axis C1a is directed to the right with respect to the longitudinal direction of the ship 71, and the first central axes C1b to C1f of the transmitting and receiving wave units 50 are arranged at intervals of an angle δ counterclockwise in order from the first central axis C1a. Also, in this embodiment, an example is shown in which the first oscillators 52a to 52f are arranged such that the first central axes C1a to C1f of the respective first oscillators 52a to 52f are equally spaced in the azimuth direction. However, as long as the ultrasonic waves TB can be transmitted simultaneously in each predetermined direction indicated by the first central axes C1a to C1f by at least the first oscillators 52a to 52f over a predetermined range set in all directions of the ship 71, there may be variations in the intervals between the first central axes C1a to C1f.

[0044] The directivity characteristics of the ultrasonic waves TB transmitted from the respective first oscillators 52a to 52f are set so as to include the first central axes C1a to C1f of the adjacent first oscillators 52. For example, as shown in FIG. 4(c), the directivity characteristics of the ultrasonic waves TB transmitted from the first oscillator 52a are set so as to include the first central axis C1b of the adjacent first oscillator 52b and the first central axis C1f of the first oscillator 52f.

[0045] On the other hand, the directivity characteristics of the ultrasonic waves TB transmitted from the first oscillator 52b and the directivity characteristics of the ultrasonic waves TB transmitted from the first oscillator 52f are also set so as to include the first central axis C1a of the first oscillator 52a. Although not shown, the directivity characteristics of the ultrasonic waves TB transmitted from the first oscillator 52b are also set so as to include the first central axis C1c of the first oscillator 52c adjacent to the opposite side of the first oscillator 52a, and the directivity characteristics of the ultrasonic waves TB transmitted from the first oscillator 52f are also set so as to include the first central axis C1e of the first oscillator 52e adjacent to the opposite side of the first oscillator 52a.

[0046] Furthermore, as shown in FIG. 4(d), the directivity characteristics of the ultrasonic waves TB transmitted from the respective first oscillators 52a to 52f are set so as to include the vertical direction in any situation where the transmitting and receiving wave unit 50 is attached to the ship 71.

[0047] As described above, the ultrasonic waves TB transmitted from the respective first oscillators 52a to 52f include the first central axes C1a to C1f of the adjacent first oscillators 52, and the directivity characteristics are set so as to include the vertical direction in the situation where the wave transmitting and receiving unit 50 is attached to the ship 71. Thereby, the wave transmitting and receiving unit 50 drives the respective first oscillators 52a to 52f simultaneously, so that the ultrasonic waves TB are irradiated from the respective first oscillators 52a to 52f in the directions of the respective first central axes C1a to C1f, and due to the directivity characteristics of the ultrasonic waves TB, the ultrasonic waves TB can be simultaneously transmitted to a predetermined range set in all directions of the ship 71 by a small number of first oscillators 52.

[0048] Further, so that the ultrasonic waves TB are irradiated over a predetermined range from the wave transmitting and receiving unit 50, the directions of the first central axes C1a to C1f and the directivity characteristics of the ultrasonic waves TB irradiated from the respective first oscillators 52a to 52f are fixed. Therefore, it is possible to eliminate the circuits for controlling the directions of the first central axes C1a to C1f in the first oscillators 52a to 52f and the circuits for controlling the directivity characteristics of the ultrasonic waves TB irradiated from the respective first oscillators 52a to 52f.

[0049] Then, the wave transmitting and receiving unit 50 can receive the reflected waves of the ultrasonic waves TB reflected from the detection target GF existing in the predetermined range for each of the first central axes C1a to C1f in a predetermined direction by the first oscillators 52a to 52f corresponding to the respective first central axes C1a to C1f. From the above, the ultrasonic sonar device 1 can be constructed for high-speed detection in a small size and at a low cost.

[0050] 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.

[0051] 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, detection result image generation means 15, and display control means 18.

[0052] Each of the transmitting units 11a, 11b, receiving units 13a to 13g, filter 14, detection result image generation means 15, and display control means 18 may be configured in hardware, implemented in software, or implemented through the cooperation of hardware and software.

[0053] 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.

[0054] Of the transmitting units 11a, 11b, receiving units 13a to 13g, filter 14, detection result image generation means 15, 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.

[0055] The transmitting unit 11a is one of the ultrasonic transmission driving means of the present invention, and based on instructions from the CPU, it 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. That is, one of the branched signals is input to the first transducer 52a via diode 12a, one is input to the first transducer 52b via diode 12b, one is input to the first transducer 52c via diode 12c, one is input to the first transducer 52d via diode 12d, one is input to the first transducer 52e via diode 12e, and one is input to the first transducer 52f via diode 12f.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] The transmitting unit 11b is one of the ultrasonic transmission driving means of the present invention and 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 makes it possible to suppress the backflow of the signal (voltage) output by the second transducer 53 when it receives the reflected wave of ultrasonic TB to the transmitting unit 11b.

[0061] 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.

[0062] Here, with reference to Figure 6, we will explain the necessity of controlling 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. Figure 6 is a schematic diagram to explain the effect of ultrasonic TB transmitted from the second transducer 53 on the first transducer 52, where (a) shows the case where a high-intensity ultrasonic TB is transmitted from the second transducer 53, and (b) shows the case where a low-intensity ultrasonic TB is transmitted from the second transducer 53.

[0063] As described above, each of the first transducers 52a to 52f has directional characteristics in the vertical direction as well. Therefore, as shown in Figures 6(a) and (b), they receive the reflected waves from the seabed SB located vertically below the ship 71, transmitted by the ultrasonic TB from the second transducer 53, before receiving the reflected waves from the seabed SB located in the direction of their own first central axis C1a to C1f.

[0064] As shown in Figure 6(a), when a high-intensity ultrasonic wave TB is transmitted from the second transducer 53, the reflected wave from the vertical seabed SB of the ultrasonic wave TB transmitted from the second transducer 53 also has a high intensity (energy). If the reflected wave from the vertical seabed SB is received by the first transducer 52 while still at high intensity, there is a risk that the object GF to be detected, which is located at approximately the same distance as the depth of the vertical seabed SB in the direction of the first central axis C1a to C1f (diagonally from the ship 71) where detection is performed by each of the first transducers 52a to 52f, will be buried by the reflected wave from the vertical seabed SB and will become undetectable.

[0065] Therefore, when the control device 10 transmits ultrasonic TB during horizontal detection using the sonar function, it executes the transmission process shown in Figure 7(a) and independently controls the transmission unit 11a and the transmission unit 11b. Figure 7(a) is a flowchart showing the transmission process.

[0066] When the control device 10 starts executing the transmission process, it first controls the transmission unit 11a to output a drive signal to drive the first transducers 52a to 52f so that ultrasonic TB is transmitted from each of the first transducers 52a to 52f at a first intensity (S1). As a result, ultrasonic TB is transmitted from the first transducers 52a to 52f at a first intensity.

[0067] Next, the control device 10 controls the transmission unit 11b to output a drive signal to drive the second transducer 53 so that ultrasonic TB is transmitted from the second transducer 53 at a second intensity weaker than the first intensity (S2), and then terminates the transmission process. As a result, ultrasonic TB is transmitted from the second transducer 53 at a second intensity.

[0068] In other words, when the ultrasonic sonar device 1 performs horizontal detection using its sonar function, it reduces the intensity of the ultrasonic TB transmitted from the second transducer 53 (second intensity) to the intensity of the ultrasonic TB transmitted from the first transducers 52a to 52f (first intensity). As a result, as shown in Figure 6(b), the intensity of the reflected wave received by the first transducers 52a to 52f after the ultrasonic TB transmitted from the second transducer 53 is reflected by the seabed SB in the vertical direction can be reduced.

[0069] Therefore, in the direction of the first central axis C1a to C1f (diagonally from the ship 71) where detection is performed by the first transducers 52a to 52f, it is possible to suppress the merging of the object to be detected GF, which is located at approximately the same distance as the depth of the vertical seabed SB, with reflected waves from the vertical seabed SB, thereby making it easier to detect.

[0070] In addition, during the S2 transmission process, the control device 10 may turn off the transmission of ultrasonic TB from the second transducer 53. By turning off the transmission of ultrasonic TB from the second transducer 53, the reflected waves from the vertical seabed SB caused by the ultrasonic TB transmitted from the second transducer 53 can be eliminated. Therefore, similar to the case where the intensity of the ultrasonic TB transmitted from the second transducer 53 (second intensity) is smaller than the intensity of the ultrasonic TB transmitted from the first transducers 52a to 52f (first intensity), it is possible to suppress the burial of the object to be detected GF located at approximately the same distance as the depth of the vertical seabed SB in the direction of the first central axis C1a to C1f (diagonal direction from the ship 71) where detection is performed by the first transducers 52a to 52f, and make it easier to detect.

[0071] Furthermore, as described above, 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, even if the transmission of ultrasonic TB from the second transducer 53 is turned off during horizontal detection using the sonar function, the detection target object GF located in the vertical direction directly below the ship 71 can be detected using only the first transducers 52a to 52f, although the detection sensitivity and / or accuracy will decrease.

[0072] 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, the specifications of the ultrasonic sonar device 1 can also be realized by always transmitting ultrasonic TB from the second transducer 53 at the same timing as the first transducers 52a to 52f. Furthermore, depending on the configuration of the second transducer 53, even if the drive signal is the same as that of the first transducers 52a to 52f, if the intensity of the ultrasonic TB output from the second transducer 53 (second intensity) is weaker than the intensity of the ultrasonic TB output from the first transducers 52a to 52f (first intensity), then only one transmitting unit 11a may be provided for the first transducers 52a to 52f and the second transducer 53, and one drive signal may be generated from this transmitting unit 11a. This allows for further significant cost reduction and miniaturization of the ultrasonic sonar device 1.

[0073] Returning to Figure 5, let's continue the explanation. Receiving units 13a to 13g are provided for each of the multiple (six) 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.

[0074] 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.

[0075] 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).

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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 from the same direction and depth, and / or at least one received signal received later in time. This temporal filtering allows the detection result image 22, described later, displayed on the display device 21 to change smoothly over time, so that the user can view the detection result image 22 without any discomfort.

[0085] 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 to the detection result image generation means 15, which will be described next, as the received signals of each of the first transducers 52a to 52f and the second transducer 53. If a virtual received signal is generated for a virtual direction, the filter 14 also includes that virtual received signal. The receiving units 13a to 13g and the filter 14 constitute the received signal generation means of the present invention.

[0086] The detection result image generation means 15 generates a detection result image 22 to be displayed on the display device 21 when the ultrasonic sonar device 1 performs horizontal detection as a sonar function. The detection result image 22 will now be explained with reference to Figure 8. Figure 8 is a schematic diagram showing the detection result image 22 displayed on the display device 21 when the ultrasonic sonar device 1 performs horizontal detection as a sonar function.

[0087] As shown in Figure 8, the detection result image 22 is a commonly known image of horizontal detection results, and displays the latest detection results for each direction in a circular format 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 across a predetermined range set for all directions of the ship 71 are displayed on the display device 21 as the detection result image 22.

[0088] The detection result image generation means 15 shown in Figure 5 generates a 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 by looking at the detection result image 22 (see Figure 8) displayed on the display device 21.

[0089] Furthermore, as shown in Figure 8, a seabed guide ring 25 is displayed in the detection result image 22. The seabed guide ring 25 corresponds to a predetermined mark of the present invention and is a ring marker drawn on the detection result image 22 at the depth of the seabed SB in the vertical direction directly beneath the ship 71, with a predetermined width (e.g., 1 cm) and a predetermined color (e.g., white) to indicate the depth of the seabed SB in the detection result image 22.

[0090] The predetermined width of the bottom guide ring 25 may be any width as long as the user can recognize it as a bottom guide ring 25. The predetermined color of the bottom guide ring 25 may also be any color as long as the user can recognize it as a bottom guide ring 25. However, it is preferable that the predetermined color be different from the color used to indicate the intensity level of reflected waves in the detection result image 22.

[0091] The seabed guide ring 25 is drawn on the detection result image 22 by the seabed guide ring generation means 15a provided in the detection result image generation means 15 shown in Figure 5. Now, referring to Figure 7(b), the seabed guide ring generation process performed by the seabed guide ring generation means 15a will be described. Figure 7(b) is a flowchart of the seabed guide ring generation process.

[0092] This seabed guide ring generation process is performed by the seabed guide ring generation means 15a each time the detection result image generation means 15 generates a detection result image 22 in response to the transmission and reception of ultrasonic TB by the first transducers 52a to 52f.

[0093] When the seabed guide ring generation means 15a starts executing the seabed guide ring processing, it first determines the depth of the seabed SB from the received signal input from the filter 14 (S11). This process S11 corresponds to the seabed depth determination means of the present invention.

[0094] The depth of this seabed submersible (SB) is determined by utilizing the fact that when a transducer receives reflected ultrasonic TB waves from a seabed submersible, the level of the signal (voltage) output from the transducer is significantly higher and the rise slope is also steeper than when it receives reflected ultrasonic TB waves from other objects.

[0095] In other words, the seabed guide ring generating means 15a determines that the received signal is due to the reception of reflected waves from the seabed SB when the level indicated by the received signal is above a predetermined level threshold and / or the amount of change in the level indicated by the received signal is above a predetermined change threshold, and identifies the depth determined by the time the determination was made as the vertical depth directly below the vessel 71.

[0096] In the S11 process, the determination of the seabed SB is made based on the intensity of the reflected ultrasonic TB received by the second transducer 53 after the second transducer 53 transmits the ultrasonic TB. As described above, the second transducer 53 has its second central axis C2 located in the vertical direction directly below the ship 71, so it can accurately determine the depth of the seabed SB in the vertical direction directly below the ship 71.

[0097] However, since the directional characteristics of each of the first transducers 52a to 52f include the vertical direction directly below the ship 71, the signals (voltages) output from the first transducers 52a to 52f also include the reflected ultrasonic waves TB from the seabed SB in the vertical direction directly below the ship 71. Therefore, although the accuracy is lower than when using the second transducer 53, the processing in S11 can also determine the depth of the seabed SB in the vertical direction directly below the ship 71 using the received signals from the first transducers 52a to 52f.

[0098] After processing in S11, the seabed guide ring generation means 15a draws a seabed guide ring 25 on the detection result image 22 at the depth of the seabed SB in the vertical direction directly below the vessel 71, as determined in processing S11 (S12), and terminates the seabed guide ring generation process. As a result, the seabed guide ring 25 is displayed on the detection result image 22 as shown in Figure 8.

[0099] Here, we will explain the role of the seabed guide ring 25. As described above, each of the first transducers 52a to 52f also has directional characteristics in the vertical direction. Since the distance to the seabed SB in the vertical direction is shorter than the distance to the seabed SB in the direction of the first central axis C1a to C1f, the first transducers 52a to 52f receive the reflected ultrasonic TB from the seabed SB in the vertical direction before receiving the reflected ultrasonic TB from the seabed SB in the direction of the first central axis C1a to C1f.

[0100] As a result, the detection result image 22 reflects the level of reflected waves from the vertical seabed SB directly beneath the vessel 71, and there is a dead zone beyond the depth of the vertical seabed SB directly beneath the vessel 71. However, it is difficult for the user to determine that a location deeper than the depth of the vertical seabed SB directly beneath the vessel 71 is a dead zone simply by looking at the detection result image 22, which reflects the reflected waves of the ultrasonic TB.

[0101] In contrast, the detection result image 22 displays a seabed guide ring 25 at the depth of the vertical seabed SB directly beneath the vessel 71, clearly indicating to the user that detection results displayed beyond the seabed guide ring 25, i.e., beyond the depth of the vertical seabed SB directly beneath the vessel 71, are invalid.

[0102] Furthermore, in the processing of S11, if the depth of the seabed SB in the vertical direction directly beneath the vessel 71 is determined by transmitting and receiving ultrasonic TB by the second transducer 53, the seabed guide ring 25 can clearly indicate to the user the depth of the seabed SB in the vertical direction directly beneath the vessel 71 in the detection result image 22 with high accuracy.

[0103] Returning to Figure 5, the explanation continues. The display control means 18 controls the display device 21 to display the detection result image 22 generated by the detection result image generation means 15, as well as other images. For example, the display control means 18 adjusts the size and display position of the detection result image 22, and also combines characters, symbols, figures, etc., with the detection result image 22 to display a single image on the display device 21.

[0104] 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.

[0105] 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.

[0106] Then, the ultrasonic sonar device 1 is operated by the control device 10, which performs the transmission process shown in Figure 7(a), outputting drive signals from the transmission unit 11a and the transmission unit 11b, and transmitting ultrasonic TBs from the first transducers 52a to 52f and the second transducer 53 of the transmitting and receiving unit 50 for a predetermined time 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 TBs transmitted from each of the first central axes C1a to C1f, ultrasonic TBs are transmitted to the ship 71 in all directions. At this time, the second intensity of the ultrasonic TBs transmitted from the second transducer 53 is weaker than the first intensity of the ultrasonic TBs transmitted from each of the first transducers 52a to 52f, respectively.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] The filtered received signals from the first central axis C1a to C1f and the second central axis C2, output by the filter 14, and the virtual received signals from the virtual directions virtually set between each of the first central axes C1a to C1f are input to the detection result image generation means 15.

[0111] Then, for the detection of the ship 71 in all directions, a detection result image 22 is generated by the detection result image generation means 15, which displays the latest detection results for each direction as a circle. At this time, the seabed guide ring generation means 15a draws a seabed guide ring 25 at the depth of the seabed SB in the vertical direction directly below the ship 71 in the detection result image 22. Then, the detection result image 22 with the drawn seabed guide ring 25 is displayed on the display device 21 by the display control means 18, as shown in Figure 8.

[0112] With the ultrasonic sonar device 1 configured as described above, the transmitting and receiving unit 50 is driven by the transmitting units 11a and 11b to transmit 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, respectively. 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.

[0113] Based on the received signals generated for each predetermined direction, the detection result image generation means 15 generates a detection result image 22 showing the latest detection results over a predetermined range. From this 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.

[0114] Here, each of the multiple first transducers 52a to 52f is fixed in the transmitting / receiving unit 50 such that its first central axis C1a to C1f is in a predetermined direction, and when the transmitting / receiving unit 50 is attached to the ship 71, its first central axis C1a to C1f is positioned at a predetermined angle θ with respect to the vertical direction. Each of the first transducers 52a to 52f has predetermined directional characteristics that include at least the first central axes C1a to C1f of adjacent first transducers 52a to 52f, and the vertical direction. As a result, with a small number of first transducers 52a to 52f, ultrasonic TB can be transmitted simultaneously over a predetermined range, and the reflected waves can be received to detect the object GF to be detected. Therefore, the ultrasonic sonar device 1 can achieve high-speed detection at low cost.

[0115] Furthermore, the transmitting and receiving unit 50 includes a second transducer 53 in addition to the multiple first transducers 52a to 52f. This second transducer 53 is fixed to the transmitting and receiving unit 50 such that the second central axis C2 is positioned vertically when the transmitting and receiving unit 50 is attached to the ship 71. By transmitting and receiving ultrasonic waves TB in the vertical direction using the second transducer 53, detection of the target object GF in the vertical direction can be performed with high precision.

[0116] Furthermore, when performing underwater detection over a predetermined range using the horizontal detection function of the sonar, the transmission of ultrasonic TB from the second transducer 53 is turned off, or the intensity of the ultrasonic TB transmitted from the second transducer 53 is made less than the intensity of the ultrasonic TB transmitted from the first transducers 52a to 52f. This eliminates the reflected waves from the seabed SB directly below the ship 71 caused by the ultrasonic TB transmitted from the second transducer 53, or reduces the intensity of the reflected waves received by the first transducers 52a to 52f when the ultrasonic TB transmitted from the second transducer 53 is reflected by the seabed SB vertically below the ship 71.

[0117] Therefore, when detecting a vessel 71 using the first transducers 52a to 52f, the detection target object GF located at a distance approximately equal to the depth of the vertical seabed SB directly below the vessel 71 in an oblique direction (direction of the first central axis C1a to C1f) can be prevented from being obscured by reflected waves from the vertical seabed SB, making it easier to detect. Thus, the ultrasonic sonar device 1 can achieve high-speed detection at low cost and can prevent the detection target object GF from being obscured by reflected waves from the vertical seabed SB.

[0118] Furthermore, the ultrasonic sonar device 1 determines the depth of the vertical seabed SB directly beneath the vessel 71, where the transmitting and receiving unit 50 is installed, based on the intensity of the reflected waves received by the transmitting and receiving unit 50, using the seabed guide ring generation means 15a. Then, on the detection result image 22, the seabed guide ring 25 is drawn by the seabed guide ring generation means 15a at the position of the vertical seabed SB depth directly beneath the vessel 71, as determined by the seabed guide ring generation means 15a. The first transducers 52a to 52f will first receive reflected waves from the vertical seabed SB directly beneath the vessel 71 before receiving reflected waves from the seabed SB in the direction of their own first central axes C1a to C1f. However, the seabed guide ring 25 attached to the detection result image 22 makes it possible to clearly indicate to the user that detection results displayed beyond the vertical seabed SB depth directly beneath the vessel 71 are invalid.

[0119] Furthermore, the ultrasonic sonar device 1 according to this embodiment achieves the effects described above through its other configurations.

[0120] 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.

[0121] 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°.

[0122] 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.

[0123] 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.

[0124] 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 Detection result image generation means 15a Seabed guide ring generation means 18 Display control means 21 Display device 22 Detection result image 25 Seabed guide ring 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 Detection target SB Bottom TB Ultrasonic wave θ Angle

Claims

1. 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 in each predetermined direction; an ultrasonic transmission driving means for driving the transmission of ultrasonic waves from the transmitting and receiving unit; a receiving signal generation means for generating received signals for each predetermined direction based on the reflected waves received by the transmitting and receiving unit; and a detection result image generation means for generating a detection result image showing the latest detection result over the predetermined range based on the received signals for each predetermined direction generated by the receiving signal generation means, wherein the transmitting and receiving unit comprises a plurality of first transducers having predetermined directional characteristics with respect to a central axis, and a second transducer fixed such that its central axis is located in the vertical direction when the transmitting and receiving unit is attached to a ship, and each of the plurality of first transducers has its central axis in the predetermined direction and is fixed such that its central axis is located at a predetermined angle with respect to the vertical direction when the transmitting and receiving unit is attached to a ship, and has the predetermined directional characteristics to include at least the central axis of an adjacent first transducer and the vertical direction. The ultrasonic sonar device is characterized in that, when performing detection in water over a predetermined range, the ultrasonic transmission driving means turns off the transmission of ultrasonic waves from the second transducer, or reduces the intensity of ultrasonic waves transmitted from the second transducer to less than the intensity of ultrasonic waves transmitted from the first transducer.

2. The ultrasonic sonar device according to claim 1, comprising a seabed depth determination means for determining the vertical depth of the seabed of a vessel on which the transmitting and receiving unit is installed, based on the intensity of the reflected waves received by the transmitting and receiving unit, wherein the detection result image generation means draws a predetermined mark on the detection result image at the position of the seabed depth determined by the seabed depth determination means.

3. The ultrasonic sonar device according to claim 2, characterized in that the seabed depth determination means determines the depth of the seabed based on the intensity of the reflected waves received by the second transducer after the ultrasonic waves are transmitted by the second transducer.

Images