Ultrasonic Sonar Device

Abstract

The device comprises a plurality of first transducers 52a-52f and a second transducer 53 fixed so that its second central axis is positioned in the vertical direction, and each of the plurality of first transducers 52a-52f is fixed so that its first central axis is positioned at a predetermined angle with respect to the vertical direction and has a predetermined directional characteristic so as to include at least the first central axis of adjacent first transducers 52a-52f and the vertical direction, and when performing underwater detection over a predetermined range, the transmitting unit 11a and the transmitting unit 11b turn off the transmission of ultrasonic waves from the second transducer 53, or make the intensity of the ultrasonic waves transmitted from the second transducer 53 smaller than the intensity of the ultrasonic waves TB transmitted from the first transducers 52a-52f.

Description

[Technical field]

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

[0002] There is known an ultrasonic sonar device that detects a detection target such as a school of fish over a predetermined range underwater by transmitting and receiving ultrasonic waves. A general fish detection device detects a detection target in a vertical direction from a ship, whereas an ultrasonic sonar device can detect a detection target present around a ship by horizontal detection, vertical cross-sectional detection, etc. Known examples of ultrasonic sonar devices include PPI sonar (searchlight sonar) and scanning sonar.

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

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

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

[0006] In contrast to such conventional ultrasonic sonar devices, the inventor has invented an ultrasonic sonar device that can achieve high-speed detection at low cost by simultaneously transmitting ultrasonic waves over a specified range using a small number of transducers and receiving the reflected waves, with the aim of further popularizing ultrasonic sonar devices. However, further improvements are necessary before this device can be brought to market as a product.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an ultrasonic sonar device that can achieve high-speed detection at low cost and can prevent the object to be detected from being buried in waves reflected from the water bottom in the vertical direction. [Means for solving the problem]

[0008] In order to achieve this object, a first aspect of the present invention is an ultrasonic sonar device comprising: a transceiver unit capable of transmitting ultrasonic waves over a predetermined range underwater and receiving reflected waves of the ultrasonic waves reflected from each position underwater for each predetermined direction; an ultrasonic transmission drive means for driving the transmission of ultrasonic waves from the transceiver unit; a reception signal generation means for generating a reception signal for each of the predetermined directions based on the reflected waves received by the transceiver unit; 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 reception signal for each of the predetermined directions generated by the reception signal generation means, wherein the transceiver unit comprises a plurality of first transducers having a predetermined directional characteristic with respect to a central axis; and a second transducer fixed so that its central axis is positioned in the vertical direction when the transmission and reception unit is attached to the ship, each of the plurality of first transducers has its central axis in the predetermined direction and is fixed so that the central axis is positioned at a predetermined angle relative to the vertical direction when the transmission and reception unit is attached to the ship, and has the predetermined directional characteristic to include at least the central axis of an adjacent first transducer and the vertical direction, and the ultrasonic transmission driving means turns off the transmission of ultrasonic waves from the second transducer or makes the intensity of the ultrasonic waves transmitted from the second transducer smaller than the intensity of the 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 bottom depth determination means for determining the vertical bottom depth of the ship on which the transmitting and receiving unit is installed based on the intensity of the reflected wave received by the transmitting and receiving unit, and the detection result image generation means draws a predetermined mark on the detection result image at the position of the bottom depth determined by the bottom depth determination means.

[0010] A third aspect of the present invention is an ultrasonic sonar device according to the second aspect, wherein the water bottom depth determination means determines the depth of the water bottom based on the intensity of the reflected wave received by the second transducer after the ultrasonic wave is transmitted by the second transducer. Effect of the Invention

[0011] According to the ultrasonic sonar device of the first aspect of the present invention, the ultrasonic transmission drive means drives the transceiver unit so as to transmit ultrasonic waves over a predetermined range underwater. Then, the reflected waves of the ultrasonic waves reflected from each position underwater for each predetermined direction are received by the transceiver unit. Based on the reflected waves received by the transceiver unit, a received signal is generated for each predetermined direction by the received signal generation means. Based on the generated received signals for each predetermined direction, a detection result image showing the latest detection result over the predetermined range is generated by the detection result image generation means. From this detection result image, it is possible to determine the presence or absence of a detection target within the predetermined range and the direction in which the detection target is present.

[0012] Here, a plurality of first transducers are fixed to the transducer unit so that their central axes are oriented in a predetermined direction and are positioned at a predetermined angle with respect to the vertical direction when the transducer unit is attached to the ship. Each first transducer has a predetermined directional characteristic that includes at least the central axis of the adjacent first transducer and the vertical direction. This allows a small number of first transducers to simultaneously transmit ultrasonic waves over a predetermined range and receive the reflected waves to detect the detection target. This allows high-speed detection to be achieved at low cost.

[0013] The wave transmitting and receiving unit further includes a second transducer in addition to the plurality of first transducers. The second transducer is fixed to the wave transmitting and receiving unit such that its central axis is positioned in the vertical direction when the wave transmitting and receiving unit is attached to the ship. By transmitting and receiving ultrasonic waves in the vertical direction using the second transducer, it is possible to detect the detection target in the vertical direction with high accuracy.

[0014] However, since the first transducer also has directional characteristics in the vertical direction, it receives the reflected wave from the bottom of the water in the vertical direction due to the ultrasonic waves transmitted from the second transducer before receiving the reflected wave from the bottom of the water in the direction of its central axis. If the strength of the ultrasonic waves transmitted from the second transducer is large, the strength of the reflected wave received by the first transducer will also be large, so there is a risk that a detection target that exists in a diagonal direction from the ship performing detection by the first transducer at a distance equal to the depth of the bottom of the water in the vertical direction will be buried in the reflected wave and will not be detectable.

[0015] On the other hand, when detecting underwater over a predetermined range, the ultrasonic transmission drive means turns off the transmission of ultrasonic waves from the second transducer, or makes the intensity of the ultrasonic waves transmitted from the second transducer smaller than that of the ultrasonic waves transmitted from the first transducer. This can eliminate the reflected waves from the bottom of the water in the vertical direction caused by the ultrasonic waves transmitted from the second transducer, or can reduce the intensity of the reflected waves received by the first transducer after the ultrasonic waves transmitted from the second transducer are reflected from the bottom of the water in the vertical direction. Therefore, it is possible to prevent a detection target that exists in the vicinity of the same distance as the depth of the bottom of the water in the vertical direction in an oblique direction from the ship where detection is performed by the first transducer from being buried in the reflected waves from the bottom of the water in the vertical direction, making it easier to detect. Therefore, there is an effect that high-speed detection can be realized at low cost, and the detection target can be prevented from being buried in the reflected waves from the bottom of the water in the vertical direction.

[0016] The ultrasonic sonar device according to the second aspect has the following effect in addition to the effect of the ultrasonic sonar device according to the first aspect. That is, the depth of the bottom in the vertical direction of the ship on which the wave transmitting and receiving unit is provided is determined by the bottom depth determination means based on the intensity of the reflected wave received by the wave transmitting and receiving unit. Then, a predetermined mark is drawn by the detection result image generation means at the position of the bottom depth determined by the bottom depth determination means on the detection result image. Before receiving the reflected wave from the bottom in the direction of its central axis, the first transducer first receives the reflected wave from the bottom in the vertical direction directly below the ship, but the predetermined mark added to the detection result image has the effect of clearly indicating to the user that the detection result displayed beyond the depth of the bottom in the vertical direction is invalid.

[0017] The ultrasonic sonar device according to the third aspect has the following effect in addition to the effect of the ultrasonic sonar device according to the second aspect. That is, ultrasonic waves are transmitted by the second transducer whose central axis is located in the vertical direction, and the depth of the bottom of the ship in the vertical direction is determined by the bottom depth determination means based on the intensity of the reflected wave received by the second transducer. This makes it possible to determine the depth of the bottom of the ship in the vertical direction with higher accuracy than when the depth of the bottom of the ship in the vertical direction is determined using the first transducer whose central axis is located at a predetermined angle with respect to the vertical direction. Therefore, there is an effect that the position of the depth of the bottom of the ship in the vertical direction can be clearly indicated to the user with high accuracy by the predetermined mark attached to the detection result image. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic diagram showing a configuration of an ultrasonic sonar device according to an embodiment of the present invention; [Diagram 2] 2 is a schematic side view showing the state in which the ultrasonic sonar device is mounted on a ship and used for underwater detection. FIG. [Diagram 3] FIG. 2A is a schematic cross-sectional view showing a wave transmitting and receiving unit of the ultrasonic sonar device, and FIG. 2B is a schematic perspective view showing an arrangement of a plurality of first transducers and a second transducer that constitute the wave transmitting and receiving unit. [Figure 4] (a) is a diagram showing a schematic diagram of the first central axis of each of the first transducers when viewed vertically from above the ship, (b) is a diagram showing a schematic diagram of the first central axis when viewed horizontally from the front side of the ship, (c) is a diagram showing a schematic diagram of the directional characteristics of ultrasound transmitted from the first transducers, and (d) is a diagram showing the directional characteristics of ultrasound transmitted from the first transducers when viewed from the front side of the ship. [Diagram 5] FIG. 2 is a block diagram showing the electrical configuration of the ultrasonic sonar device. [Figure 6] 5A and 5B are schematic diagrams for explaining the effect of ultrasound transmitted from the second transducer on the first transducer, where (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. [Figure 7] 10A is a flowchart showing a transmission process, and FIG. 10B is a flowchart showing a bottom guide link generation process. [Figure 8] 2 is a diagram showing an example of a display screen displayed on a display device of the ultrasonic sonar device. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, the embodiments for carrying out the present invention will be described with reference to the accompanying drawings. Note that each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components that are not described in the independent claims showing the highest concept of the present invention will be described as optional components. In addition, in each drawing, substantially the same configuration is given the same reference numeral, and duplicated explanations will be omitted or simplified.

[0020] First, an ultrasonic sonar device 1 according to an embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram showing the configuration of the ultrasonic sonar device 1, and Figure 2 is a schematic diagram showing a side view of a ship 71 equipped with the ultrasonic sonar device 1 performing underwater detection.

[0021] 1 and 2, the ultrasonic sonar device 1 is mounted on a ship 71 and has at least a sonar function of horizontally detecting detection targets GF, such as schools of fish, over a predetermined range around the ship 71 in the waters of the sea, lake, river, or the like on which the ship 71 floats. Horizontal detection is a predetermined range in all directions as seen from the ship 71, and detects detection targets GF included in the predetermined range. The ultrasonic sonar device 1 may have a sonar function of performing vertical cross-sectional detection in addition to horizontal detection, and may also have a fish detection function of detecting detection targets GF present in the vertical direction directly below the ship 71 and displaying the detection results in a chronological order.

[0022] The ultrasonic sonar device 1 includes a main body 5, an operation button 31 provided on the main body 5, a display device 21 formed integrally with the main body 5, a wave transmission / reception unit 50 that transmits and receives ultrasonic waves TB for detecting a detection target GF, and a lifting device 41 that raises and lowers the wave transmission / reception unit 50. The main body 5, the operation button 31, and the display device 21 are disposed in the wheelhouse of the ship 71, while the wave transmission / reception unit 50 and the lifting device 41 are disposed in the bottom of the ship 71. The wave transmission / reception unit 50 is raised and lowered by the lifting device 41, so that it can freely appear and disappear underwater from the bottom of the ship 71.

[0023] The operation button 31 is a button that can be operated by the user, and is operated when the user issues various instructions or settings to the ultrasonic sonar device 1. For example, the user operates the operation button 31 to turn the ultrasonic sonar device 1 on / off, set the brightness of the image displayed by the display device 21, and issue instructions to start / end execution of horizontal detection using the sonar function.

[0024] 2, the ultrasonic sonar device 1 transmits (radiates) ultrasonic waves TB in a cone shape within a predetermined range from the wave transmitting and receiving unit 50 with the wave transmitting and receiving unit 50 protruding from the bottom of the ship 71. The wave transmitting and receiving unit 50 is configured to be able to receive reflected waves of the ultrasonic waves TB reflected from a detection target GF included in the predetermined cone-shaped range, the bottom of the sea or lake (hereinafter collectively referred to as the "bottom SB"). The detailed configuration of the wave transmitting and receiving unit 50 will be described later with reference to FIGS. 3 and 4.

[0025] The display device 21 displays the detection result based on the reception signal generated by receiving units 13a-13g, which will be described later, and a filter 14 (see FIG. 5) when the transmitting / receiving unit 50 receives the reflected wave of the ultrasonic wave TB, and is configured, for example, by a liquid crystal display or an organic EL (Electro-Luminescence) display. When the ultrasonic sonar device 1 executes horizontal detection using the search function, a detection result image 22 and the like are displayed on the display device 21. Details of the detection result image 22 will be described later with reference to FIG. 8.

[0026] Next, a detailed configuration of the wave transmitting and receiving unit 50 will be described with reference to Fig. 3 and Fig. 4. Fig. 3(a) is a schematic cross-sectional view showing the wave transmitting and receiving unit 50, and Fig. 3(b) is a schematic perspective view showing an arrangement of a plurality of first transducers 52 (52a to 52f) and a second transducer 53 that constitute the wave transmitting and receiving unit 50.

[0027] 4(a) is a diagram showing the first central axes C1a-C1f of the first transducers 52a-52f when viewed vertically from above the ship 71, and FIG. 4(b) is a diagram showing the first central axes C1a-C1f of the first transducers 52a-52f when viewed horizontally from the front side of the ship 71. FIG. 4(c) is a diagram showing the directional characteristics of ultrasonic waves TB transmitted from adjacent first transducers 52a, 52b, and 52f, and FIG. 4(d) is a diagram showing the directional characteristics of ultrasonic waves TB transmitted from the first transducers 52a and 52d when viewed from the front side of the ship 71.

[0028] As shown in FIG. 3, the wave transmitting / receiving unit 50 has a structure in which a plurality of (six in the example shown in FIG. 3) first transducers 52 (first transducer 52a, first transducer 52b, first transducer 52c, first transducer 52d, first transducer 52e, first transducer 52f) that transmit ultrasonic waves TB in a predetermined direction and receive the reflected waves are housed in a case 51 and molded. Each of the first transducers 52 is a disk-shaped structure having the same size and shape. Similarly to the first transducer 52, the second transducer 53 also has a disk-shaped shape. However, the size of the second transducer 53 is determined according to the required characteristics. That is, the second transducer 53 may be the same size as the first transducer 52, or may be a different size from the first transducer 52.

[0029] Each of the first transducer 52 and the second transducer 53 includes a base material 54 and a piezoelectric element 55. The base material 54 is a disk-shaped resin plate material that also serves as an acoustic matching layer, and is made of, for example, glass epoxy.

[0030] The piezoelectric element 55 is a plate-like object made of piezoelectric ceramics, and for example, a disk-shaped plate-like object made of lead zirconate titanate (PZT) is used. The piezoelectric element 55 has a front electrode (not shown) formed on its front surface, which is entirely bonded to the base material 54 via an adhesive layer (not shown), and a rear electrode (not shown) formed on its rear surface opposite the front surface. Lead wires are electrically connected to the front electrode and the rear electrode, respectively.

[0031] When a driving voltage is applied from a transmitting unit 11a or a transmitting unit 11b (see FIG. 5) described later via a front electrode and a back electrode, the piezoelectric element 55 deforms in the thickness direction to vibrate the base material 54. This vibration of the base material 54 causes each of the first oscillator 52 and the second oscillator 53 to generate an ultrasonic wave TB.

[0032] In addition, when the reflected wave of the ultrasonic wave TB vibrates the substrate 54 of each of the first transducer 52 and the second transducer 53, the vibration deforms the piezoelectric element 55, generating a voltage between the front electrode and the back electrode. The first transducers 52a-52f and the second transducer 53 output the voltage generated between the front electrode and the back electrode to the corresponding receiving units 13a-13g, which will be described later, to generate reception signals corresponding to the reflected wave received by each of the first transducers 52a-52f and the second transducer 53.

[0033] The case 51 has an opening at one end. Yes A plurality of first transducers 52 and second transducers 53 are housed in the case 51. The second transducer 53 is disposed at the center of the case 51. Six first transducers 52 are disposed around the second transducer 53 in the order of first transducer 52a, first transducer 52b, first transducer 52c, first transducer 52d, first transducer 52e, and first transducer 52f in a counterclockwise direction as viewed from the front surface side of the base material 54. The acoustic radiation surface formed on the front surface of the base material 54 of each of the first transducers 52 and the acoustic radiation surface formed on the front surface of the base material 54 of the second transducer 53 are all located on one imaginary spherical surface.

[0034] In this embodiment, the number of first transducers 52 is six, but the number of first transducers 52 may be any number of three or more, preferably four or more, and more preferably six or more. However, if the number of first transducers 52 is large, the configuration of the ultrasonic sonar device 1 becomes complicated, large, and expensive, so the number of first transducers 52 is preferably ten or less, and more preferably eight or less.

[0035] Here, the direction of the first central axis C1a (which can also be said to be the direction of the normal vector of the first oscillator 52a) that is the central axis perpendicular to the center of the front surface (sound radiation surface) of the base material 54 can be understood as the sound radiation direction of the first oscillator 52a. Similarly to the first oscillator 52a, the first oscillator 52b is defined as the first central axis C1b, the first oscillator 52c is defined as the first central axis C1c, the first oscillator 52d is defined as the first central axis C1d, the first oscillator 52e is defined as the first central axis C1e, and the first oscillator 52f is defined as the first central axis C1f. Each of the first central axes C1b to C1f can be understood as the sound radiation direction of the corresponding first oscillator 52b to 52f.

[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 base material 54 (which can also be said to be the direction of the normal vector of the second oscillator 53), can be understood to be the acoustic radiation direction of the second oscillator 53.

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

[0038] Here, the wave transmitting / receiving unit 50 is attached to the ship 71 so that the direction of the second central axis C2 of the second transducer 53 is vertical. That is, the second transducer 53 transmits (irradiates) ultrasonic waves TB in the vertical direction directly below the ship 71. Due to the presence of this second transducer 53, the ultrasonic sonar device 1 can detect the detection target GF in the vertical direction with high accuracy. Note that it is preferable that the directional characteristics of the ultrasonic waves TB transmitted from the second transducer 53 are a narrow beam with a small directional angle. This can further increase the accuracy of detection of the detection target GF in the vertical direction.

[0039] On the other hand, in the wave transmitting and receiving unit 50, the first transducers 52a-52f are arranged with the sound emitting surface of each of the first transducers 52a-52f inclined such that the first central axes C1a-C1f form a predetermined angle θ with respect to the second central axis C2 (i.e., the vertical direction when the wave transmitting and receiving unit 50 is attached to the ship 71), as shown in Fig. 3. As a result, the sound emitting direction of each of the first transducers 52a-52f faces in a direction different from the vertical direction directly below the ship 71, as shown in Fig. 4(b).

[0040] In this embodiment, the first transducers 52a-52f are inclined with their acoustic radiation surfaces facing inward (toward the side where the second transducer 53 is located) (see FIG. 3). In this case, it is preferable that each of the first central axes C1a-C1f forms a predetermined angle θ with respect to the second central axis C2, the angle being selected from a range of 20° or more and 50° or less. In this embodiment, the predetermined angle θ is 30°. As shown in FIG. 3(a), each of the first central axes C1a-C1f and the second central axis C2 are converged at one point.

[0041] 4(a), when the wave transmitting / receiving unit 50 is attached to the ship 71 and viewed vertically from above the ship 71, the first central axes C1a to C1f of the first transducers 52a to 52f are disposed at equal intervals in the azimuth direction so that adjacent first central axes C1a to C1f form the same angle δ. When the number of first transducers 52 is n, the angle δ is (360 / n)° (when the number of first transducers 52 is six, the angle δ is 60°).

[0042] As a result, the transmitting and receiving unit 50 can transmit ultrasonic waves TB simultaneously in each of the predetermined directions indicated by the first central axes C1a to C1f using at least the first transducers 52a to 52f over a predetermined range set in all directions of the ship 71, and can also receive reflected waves in each of the predetermined directions.

[0043] 4(a) and 4(b), the wave transmitting / receiving unit 50 is attached to the ship 71 so that, when the ship 71 is viewed vertically from above, the first central axis C1a faces the rightward direction with respect to the longitudinal direction of the ship 71, and the first central axes C1b to C1f are arranged counterclockwise from the first central axis C1a at intervals of an angle δ. In addition, in the present embodiment, an example is shown in which the first transducers 52a to 52f are arranged so that the first central axes C1a to C1f of the first transducers 52a to 52f are equally spaced apart in the azimuth direction, but it is only necessary that the first transducers 52a to 52f can transmit ultrasonic waves TB simultaneously in each of the predetermined directions indicated by the first central axes C1a to C1f over a predetermined range set in all azimuth directions of the ship 71, and the intervals between the first central axes C1a to C1f may vary.

[0044] The directional characteristics of the ultrasonic waves TB transmitted from each of the first transducers 52a to 52f are set to include the first central axes C1a to C1f of the adjacent first transducers 52. For example, as shown in Fig. 4(c), the directional characteristics of the ultrasonic waves TB transmitted from the first transducer 52a are set to include the first central axis C1b of the adjacent first transducer 52b and the first central axis C1f of the first transducer 52f.

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

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

[0047] As described above, the ultrasonic waves TB transmitted from each of the first transducers 52a-52f include the first central axes C1a-C1f of the adjacent first transducers 52, and the directivity is set so as to include the vertical direction when the transducer unit 50 is attached to the ship 71. As a result, by simultaneously driving each of the first transducers 52a-52f, the transducer unit 50 irradiates ultrasonic waves TB from each of the first transducers 52a-52f in the direction of the respective first central axes C1a-C1f, and due to the directivity of the ultrasonic waves TB, it is possible to simultaneously transmit the ultrasonic waves TB to a predetermined range set in all directions of the ship 71 using a small number of first transducers 52.

[0048] Furthermore, the directions of the first central axes C1a-C1f of the first transducers 52a-52f and the directional characteristics of the ultrasonic waves TB radiated from the first transducers 52a-52f are fixed so that the ultrasonic waves TB are radiated over a predetermined range from the wave transmitting / receiving unit 50. This makes it possible to eliminate the need for circuits for controlling the directions of the first central axes C1a-C1f of the first transducers 52a-52f and circuits for controlling the directional characteristics of the ultrasonic waves TB radiated from the first transducers 52a-52f.

[0049] The wave transmitting / receiving unit 50 can receive the reflected waves of the ultrasonic waves TB reflected from the detection target GF present within the predetermined range by the first transducers 52a-52f corresponding to each of the first central axes C1a-C1f, which are predetermined directions. As described above, the ultrasonic sonar device 1 can be constructed to perform high-speed detection in a small size at low cost.

[0050] The wave transmitting / receiving unit 50 is arranged and housed in the case 51 with the first transducers 52a-52f and the second transducer 53 closely packed together so that the first central axes C1a-C1f and the second central axis C2 are respectively in the above-mentioned directions, and is fixed by a filler. As the filler, a waterproof resin material (e.g., urethane resin, etc.) is used, which has a lower specific acoustic impedance than the base material 54 that is the acoustic matching layer of the first transducer 52 and the second transducer 53. The filler is filled so that the outer surface is flush with the opening of the case 51, thereby closing the opening of the case 51.

[0051] Next, the electrical configuration of the ultrasonic sonar device 1 will be described with reference to Fig. 5. Fig. 5 is a block diagram showing the electrical configuration of the ultrasonic sonar device 1. The ultrasonic sonar device 1 has a control device 10 inside its main body 5, which is provided with transmitting units 11a, 11b, diodes 12a-12g, receiving units 13a-13g, a filter 14, a detection result image generating means 15, and a display control means 18.

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

[0053] The control device 10 includes a CPU (Centre), which is a computing device (not shown). tr The main components of the CPU are the flash memory (a non-volatile processing unit), the program to be executed by the CPU and fixed values ​​referenced by the program, and / or the ROM (Read Only Memory), a non-volatile memory that cannot be rewritten; and the RAM (Random Access Memory), a volatile memory that can be read and written and that temporarily stores various data when the CPU is executing the program. e These are connected via a bus line.

[0054] Among the transmitting units 11a, 11b, the receiving units 13a to 13g, the filter 14, the detection result image generating means 15, and the display control means 18, the parts that are realized by software or by a combination of hardware and software are realized by the CPU executing a program.

[0055] The transmission unit 11a corresponds to one of the ultrasonic transmission driving means of the present invention, and generates one driving signal for transmitting ultrasonic waves TB from the first transducers 52a to 52f based on an instruction from the CPU. The output of one driving signal generated by the transmission unit 11a is branched between the transmission unit 11a and the diodes 12a to 12f, and distributed to each of the first transducers 52a to 52f. That is, after branching, one is input to the first transducer 52a via the diode 12a, one is input to the first transducer 52b via the diode 12b, one is input to the first transducer 52c via the diode 12c, one is input to the first transducer 52d via the diode 12d, one is input to the first transducer 52e via the diode 12e, and one is input to the first transducer 52f via the diode 12f.

[0056] The diodes 12a to 12f are elements that pass the drive signals generated by the transmitting unit 11a and input them to the corresponding first oscillators 52a to 52f, and also block the signals (voltages) generated by receiving reflected waves in each of the first oscillators 52a to 52f from being transmitted to the transmitting unit 11a or the branching points of the drive signals output from the transmitting unit 11a to each of the first oscillators 52a to 52f.

[0057] A single drive signal generated by the transmission unit 11a is branched and input to the first transducers 52a-52f via the diodes 12a-12f, so that the first transducers 52a-52f, which have the same shape and size, are driven simultaneously and can output ultrasonic waves TB of the same intensity at the same timing. Therefore, ultrasonic waves TB can be transmitted uniformly in a predetermined direction (i.e., the direction of the first central axes C1a-C1f) included in a predetermined range set in all directions with respect to the ship 71, so that the detection sensitivity can be made uniform in all predetermined directions.

[0058] Furthermore, since one transmission unit 11a is provided for the plurality of first transducers 52a to 52f, it is possible to achieve significant cost reduction and size reduction compared to the case where a transmission unit 11a is provided for each of the first transducers 52a to 52f.

[0059] In addition, the diodes 12a-12f are provided between the transmission unit 11a and each of the first transducers 52a-52f, downstream of the branching point where the drive signal output from the transmission unit 11a branches toward each of the first transducers 52a-52f, so that the signal (voltage) output by each of the first transducers 52a-52f receiving the reflected wave of the ultrasonic wave TB can be prevented from flowing back to the transmission unit 11a or from entering the signal line of the other first transducers 52a-52f via the branching point, causing interference. Therefore, even if one transmission unit 11a is provided for the multiple (six) first transducers 52a-52f, the independence of the signals (voltages) output from each of the first transducers 52a-52f can be ensured.

[0060] The transmission unit 11b corresponds to one of the ultrasonic transmission drive means of the present invention, and generates a drive signal for transmitting ultrasonic waves TB from the second transducer 53 based on an instruction from the CPU. The output of the drive signal generated by the transmission unit 11b is input to the second transducer 53 via the diode 12g. The diode 12g is an element for passing the drive signal generated by the transmission unit 11b and inputting it to the second transducer 53, and for blocking a signal (voltage) generated by receiving a reflected wave at the second transducer 53 so as not to be transmitted to the transmission unit 11b. This diode 12g can suppress the signal (voltage) output by the second transducer 53 by receiving a reflected wave of the ultrasonic wave TB from flowing back to the transmission unit 11b.

[0061] In the ultrasonic sonar device 1, the transmission unit 11b that generates a drive signal for the second transducer 53 that transmits ultrasonic waves TB in the vertical direction directly below the ship 71 is provided separately from the transmission unit 11a that generates drive signals for the first transducers 52a to 52f. This allows the ultrasonic sonar device 1 to function as a normal fish finder by turning off the transmission of ultrasonic waves TB from the first transducers 52a to 52f and transmitting ultrasonic waves TB only from the second transducer 53, or to control the transmission of ultrasonic waves TB from the second transducer 53 independently of the transmission of ultrasonic waves TB from the first transducers 52a to 52f when performing horizontal detection as a sonar function.

[0062] Here, when performing horizontal detection as a sonar function, the necessity of controlling the transmission of ultrasonic waves TB from the second transducer 53 independently of the transmission of ultrasonic waves TB from the first transducers 52a to 52f will be described with reference to Fig. 6. Fig. 6 is a schematic diagram for explaining the influence of ultrasonic waves TB transmitted from the second transducer 53 on the first transducer 52, in which (a) shows a case where ultrasonic waves TB with high intensity are transmitted from the second transducer 53, and (b) shows a case where ultrasonic waves TB with low intensity are 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, so before receiving a reflected wave from the bottom of the water SB in the direction of its own first central axis C1a to C1f, it will receive a reflected wave from the bottom of the water SB in the vertical direction directly below the ship 71 due to the ultrasonic waves TB transmitted from the second transducer 53, as shown in Figures 6(a) and (b).

[0064] 6(a), when ultrasonic waves TB with high intensity are transmitted from the second transducer 53, the reflected waves reflected from the water bottom SB in the vertical direction of the ultrasonic waves TB transmitted from the second transducer 53 also have high intensity (energy). If the reflected waves reflected from the water bottom SB in the vertical direction while maintaining their high intensity are received by the first transducer 52, the detection target GF existing in the vicinity of the same distance as the depth of the water bottom SB in the vertical direction in the direction of the first central axes C1a-C1f (diagonal direction from the ship 71) where detection is performed by each of the first transducers 52a-52f may be buried in the reflected waves from the water bottom SB in the vertical direction and may not be detectable.

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

[0066] When the control device 10 starts the execution of the transmission process, first, the control device 10 controls the transmission unit 11a to output a drive signal for driving the first transducers 52a-52f so that the first transducers 52a-52f transmit ultrasonic waves TB at a first intensity (S1). As a result, the first transducers 52a-52f transmit ultrasonic waves TB at the first intensity.

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

[0068] That is, when performing horizontal detection using the sonar function, the ultrasonic sonar device 1 sets the intensity (second intensity) of the ultrasonic waves TB transmitted from the second transducer 53 to be smaller than the intensity (first intensity) of the ultrasonic waves TB transmitted from the first transducers 52a to 52f. This makes it possible to reduce the intensity of the reflected waves received by the first transducers 52a to 52f after the ultrasonic waves TB transmitted from the second transducer 53 are reflected by the water bottom SB in the vertical direction, as shown in Fig. 6(b).

[0069] Therefore, 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, the detection target GF located at approximately the same distance as the depth of the vertical water bottom SB can be prevented from being buried in the reflected waves from the vertical water bottom SB, making it easier to detect.

[0070] In the process of S2 of the transmission process, the control device 10 may turn off the transmission of the ultrasonic waves TB from the second transducer 53. By turning off the transmission of the ultrasonic waves TB from the second transducer 53, it is possible to eliminate the reflected waves of the ultrasonic waves TB transmitted from the second transducer 53 in the vertical direction from the bottom SB of the water. Therefore, in the same manner as in the case where the intensity (second intensity) of the ultrasonic waves TB transmitted from the second transducer 53 is made smaller than the intensity (first intensity) of the ultrasonic waves TB transmitted from the first transducers 52a to 52f, it is possible to suppress the detection target GF present in the vicinity of the same distance as the depth of the bottom SB in the vertical direction in the direction of the first central axes C1a to C1f (diagonal direction from the ship 71) where detection is performed by the first transducers 52a to 52f from being buried in the reflected waves from the bottom SB in the vertical direction, making it easier to detect.

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

[0072] In this embodiment, the transmission unit 11a corresponding to the first transducers 52a to 52f and the transmission unit 11b corresponding to the second transducer 53 are provided separately, but the specifications of the ultrasonic sonar device 1 can be realized even if the transmission of the ultrasonic wave TB from the second transducer 53 is always performed at the same timing as the first transducers 52a to 52f, and even if the drive signal is the same as that of the first transducers 52a to 52f, if the intensity (second intensity) of the ultrasonic wave TB output from the second transducer 53 is weaker than the intensity (first intensity) of the ultrasonic wave TB output from the first transducers 52a to 52f due to the configuration of the second transducer 53, only one transmission unit 11a may be provided for the first transducers 52a to 52f and the second transducer 53, and one drive signal may be generated from this transmission unit 11a. This allows the ultrasonic sonar device 1 to be further significantly reduced in cost and size.

[0073] Returning to Fig. 5, the description will be continued. Receiving units 13a to 13g are provided for each of the multiple (six) first transducers 52a to 52f and second transducers 53, and when the corresponding first transducers 52a to 52f and second transducers 53 receive the reflected waves of the ultrasonic waves TB, they acquire signals (voltages) output according to the intensities of the reflected waves, and perform predetermined processing on the acquired signals.

[0074] That is, the receiving unit 13a is connected to the first oscillator 52a, and performs a predetermined process on a signal (voltage) outputted according to the intensity of the reflected wave received by the first oscillator 52a. The receiving unit 13b is connected to the first oscillator 52b, the receiving unit 13c is connected to the first oscillator 52c, the receiving unit 13d is connected to the first oscillator 52d, the receiving unit 13e is connected to the first oscillator 52e, the receiving unit 13f is connected to the first oscillator 52f, and the receiving unit 13g is connected to the second oscillator 53. Each of the receiving units 13b to 13g also performs a predetermined process on a signal (voltage) outputted according to the intensity of the reflected wave received by the connected first oscillator 52b to 52f or the second oscillator 53.

[0075] The receiving units 13a to 13g are each It has an amplifier circuit and an analog-to-digital conversion circuit, and as a specified process, the input signal (voltage) is amplified by the amplifier circuit and then converted into a digital signal (digital value) by the analog-to-digital conversion circuit (AD conversion circuit).

[0076] Then, the receiving unit 13a outputs a digital signal obtained by an AD conversion circuit as a reception signal received by the first transducer 52a (a reception signal of a reflected wave of the ultrasonic wave TB) to the filter 14. Similarly, the receiving unit 13b outputs a digital signal obtained by each AD conversion circuit as a reception signal of the first transducer 52b, the receiving unit 13c outputs a digital signal obtained by the first transducer 52c, the receiving unit 13d outputs a digital signal obtained by the first transducer 52d, the receiving unit 13e outputs a digital signal obtained by the first transducer 52e, the receiving unit 13f outputs a digital signal obtained by the first transducer 52f, and the receiving unit 13g outputs a digital signal obtained by the second transducer 53 to the filter 14.

[0077] As described above, one transmitting unit 11a is provided for the multiple (six) first transducers 52a-52f to reduce costs and size, whereas receiving units 13a-13f are provided for each of the multiple first transducers 52a-52f, making it possible to perform predetermined processing on each signal (voltage) while maintaining the independence of the signal (voltage) output from each of the first transducers 52a-52f. Meanwhile, since the ultrasonic sonar device 1 is configured with fewer transducers than conventional scanning sonars, even if receiving units 13a-13f are provided for each of the first transducers 52a-52f, the overall receiving unit can be made smaller and costs can be reduced compared to conventional scanning sonars.

[0078] The reception signals output from the reception units 13a to 13g are original reception signals that indicate the raw intensity values ​​of the reflected waves of the ultrasonic waves TB received by the corresponding first transducers 52a to 52f and second transducer 53. The original reception signals are reception signals before filtering by the filter 14, which will be described next.

[0079] The filter 14 performs a predetermined filtering process on the reception signals (original reception signals) output from the reception units 13a to 13g to each of the first transducers 52a to 52f and the second transducer 53. The predetermined filtering process includes spatial filtering and may also include temporal filtering.

[0080] As the spatial filtering process, filtering is performed in the azimuth direction and the distance direction on the original reception signal of each of the first transducers 52a to 52f that receives the reflected wave of the ultrasonic wave TB for each predetermined direction, for the purpose of reducing noise and / or improving the resolution, etc. The spatial filtering process also includes filtering in the distance direction on the original reception signal of the second transducer 53 that receives the reflected wave of the ultrasonic wave TB from the vertical direction directly below the ship 71.

[0081] Here, the azimuth direction is the direction in which the first central axes C1a to C1f of the first transducer 52a to first transducer 52f, i.e., the respective acoustic emission directions, are aligned, in other words, the circumferential direction centered on the ship 71. Moreover, the distance direction is the direction in which ultrasonic waves TB are transmitted from the first central axes C1a to C1f of the first transducer 52a to first transducer 52f and the second central axis C2 of the second transducer 53, i.e., the respective acoustic emission directions themselves.

[0082] Furthermore, when performing horizontal detection using the sonar function, the ultrasonic sonar device 1 performs detection using a small number of transducers, the first transducers 52a to 52f (six in this embodiment), and therefore the azimuth resolution is significantly reduced. Therefore, in the horizontal detection, the filter 14 sets a virtual direction at a midpoint between the first central axes C1a to C1f adjacent to the first central axes C1a to C1f of the first transducers 52a to 52f, which are the predetermined direction in which the ultrasonic wave TB is transmitted and received, and generates a reception signal, which is assumed to have been virtually transmitted and received in the virtual direction, from the reception signals of the first transducers 52a to 52f.

[0083] By generating virtual reception signals in virtual directions, the number of directions in which ultrasonic waves TB are transmitted and received, including the virtual directions, can be doubled (12 directions in this embodiment) as the actual number of first transducers 52, thereby improving the azimuth resolution.

[0084] On the other hand, the temporal filtering process is a process in which a received signal indicating the intensity of a reflected wave reflected from a certain depth in a certain direction is filtered together with at least one received signal received earlier in time from the same direction and the same depth and / or at least one received signal received later in time. This temporal filtering process allows a detection result image 22, which will be described later and is displayed on the display device 21, to be changed smoothly over time, allowing the user to visually recognize the detection result image 22 without feeling any discomfort.

[0085] The filter 14 performs a predetermined filter process on the original reception signals of each of the first transducer 52a to 52f and the second transducer 53, and outputs the values ​​obtained by the filter process as the reception signals of each of the first transducer 52a to 52f and the second transducer 53, and also outputs the virtual reception signals, if any, in a virtual direction to a detection result image generating means 15 described next. The receiving units 13a to 13g and the filter 14 correspond to the reception signal generating means of the present invention.

[0086] The detection result image generating 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. Here, the detection result image 22 will be described with reference to Fig. 8. Fig. 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] 8, the detection result image 22 is a generally known horizontal detection result image, and is a circular display of the latest detection results in each azimuth direction for the omnidirectional detection of the ship 71. Specifically, the latest detection results over a predetermined range set in all azimuth directions of the ship 71 are displayed on the display device 21 as the detection result image 22 based on the reception signals for each direction of the first central axes C1a to C1f of the first transducers 52a to 52f output from the filter 14 and the virtual reception signals for each direction virtually set between those directions.

[0088] The detection result image generating means 15 shown in Fig. 5 generates a detection result image 22 using the filtered reception signals of the first transducers 52a to 52f input from the filter 14 and virtual reception signals for each virtually set direction. The user can determine in which direction the detection target GF currently exists with respect to the ship 71 by the detection result image 22 (see Fig. 8) displayed on the display device 21.

[0089] 8, a water bottom guide ring 25 is displayed on the detection result image 22. The water bottom 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 position of the water bottom SB with a predetermined width (e.g., 1 cm) and a predetermined color (e.g., white) to indicate the depth position of the water bottom SB in the vertical direction directly below the ship 71 in the detection result image 22.

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

[0091] The water bottom guide ring 25 is drawn on the detection result image 22 by the water bottom guide ring generating means 15a provided in the detection result image generating means 15 shown in Fig. 5. Here, the water bottom guide ring generating process executed by the water bottom guide ring generating means 15a will be described with reference to Fig. 7(b). Fig. 7(b) is a flowchart showing the water bottom guide ring generating process.

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

[0093] When the water-bottom guiding ring generating means 15a starts executing the water-bottom guiding ring process, it first determines the depth of the water bottom SB from the received signal input from the filter 14 (S11). This process of S11 corresponds to the water-bottom depth determining means of the present invention.

[0094] The depth of the bottom SB is determined by utilizing the fact that when the transducer receives a reflected ultrasonic wave TB from the bottom SB, the level of the signal (voltage) output from the transducer is much higher than when a reflected ultrasonic wave TB is received from another object, and the rising slope is also steeper.

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

[0096] The determination of the water bottom SB in the process of S11 is performed based on the intensity of the reflected wave of the ultrasonic wave TB received by the second transducer 53 when the second transducer 53 transmits the ultrasonic wave TB. As described above, the second transducer 53 has its second central axis C2 positioned in the vertical direction directly below the ship 71, so that the depth of the water bottom SB in the vertical direction directly below the ship 71 can be determined with high accuracy.

[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 reflected waves of ultrasonic waves TB from the water bottom SB in the vertical direction directly below the ship 71. Therefore, although the accuracy is lower than when the second transducer 53 is used, the process of S11 can also determine the depth of the water bottom SB in the vertical direction directly below the ship 71 using the received signals from the first transducers 52a to 52f.

[0098] After the process of S11, the water bottom guide ring generating means 15a draws the water bottom guide ring 25 on the detection result image 22 at the depth of the water bottom SB in the vertical direction directly below the ship 71 determined in the process of S11 (S12), and ends the water bottom guide ring generating process. As a result, the water bottom guide ring 25 is displayed on the detection result image 22 as shown in FIG.

[0099] Here, the role of the water bottom guide ring 25 will be described. As described above, each of the first transducers 52a-52f has directional characteristics in the vertical direction as well. Since the distance to the water bottom SB in the vertical direction is shorter for each of the first transducers 52a-52f than the distance to the water bottom SB in the direction of each of the first central axes C1a-C1f, the first transducers 52a-52f receive the reflected wave of the ultrasonic wave TB from the water bottom SB in the vertical direction before receiving the reflected wave of the ultrasonic wave TB from the water bottom SB in the direction of the first central axes C1a-C1f.

[0100] As a result, the detection result image 22 reflects the level of the reflected waves from the water bottom SB in the vertical direction directly below the ship 71, and the area beyond the depth of the water bottom SB in the vertical direction directly below the ship 71 becomes a dead zone. However, it is difficult for a user to determine that a position deeper than the depth of the water bottom SB in the vertical direction directly below the ship 71 is a dead zone just by looking at the detection result image 22 that reflects the reflected waves of the ultrasonic waves TB.

[0101] In contrast, the detection result image 22 displays a bottom guide ring 25 at the depth of the bottom SB in the vertical direction directly below the ship 71, thereby clearly indicating to the user that the detection result displayed beyond the bottom guide ring 25, i.e., beyond the depth of the bottom SB in the vertical direction directly below the ship 71, is invalid.

[0102] Furthermore, in the processing of S11, if the depth of the water bottom SB in the vertical direction directly below the ship 71 is determined by transmitting and receiving ultrasonic waves TB by the second transducer 53, the water bottom guide ring 25 can clearly show the user the depth of the water bottom SB in the vertical direction directly below the ship 71 in the detection result image 22 with high accuracy.

[0103] Returning to Fig. 5, the explanation will be continued. The display control means 18 performs control for displaying the detection result image 22 generated by the detection result image generation means 15 and other images on the display device 21. 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 one image on the display device 21.

[0104] Next, the ultrasonic sonar device 1 of the present embodiment configured as described above is used to detect horizontal Detect This article explains how to do this.

[0105] When a user turns on the power to the ultrasonic sonar device 1 via the operation button 31, or when the power is turned on and an instruction is given to start performing horizontal detection using the sonar function, the ultrasonic sonar device 1 first drives the lifting device 41 to make the transmitting and receiving unit 50 appear underwater from the bottom of the ship 71.

[0106] 7(a), the control device 10 of the ultrasonic sonar device 1 outputs drive signals from the transmission unit 11a and the transmission unit 11b, and transmits ultrasonic waves TB from the first transducers 52a-52f and the second transducer 53 of the wave transmitting / receiving unit 50 in the directions of the first central axes C1a-C1f and the second central axis C2, respectively, for a predetermined time. Due to the directional characteristics of the ultrasonic waves TB transmitted from each of the first central axes C1a-C1f, the ultrasonic waves TB are transmitted in all directions to the ship 71. At this time, the ultrasonic waves TB are transmitted such that the second intensity of the ultrasonic waves TB transmitted from the second transducer 53 is weaker than the first intensity of the ultrasonic waves TB transmitted from each of the first transducers 52a-52f.

[0107] The ultrasonic waves TB transmitted from the first transducers 52a-52f and the second transducer 53 are reflected from the detection target GF and the water bottom SB present within a predetermined range from which the ultrasonic waves TB are transmitted. The reflected waves are received by the first transducers 52a-52f and the second transducer 53, and signals (voltages) are output from the first transducers 52a-52f and the second transducer 53 as the intensities of the reflected waves received in the directions of the first central axes C1a-C1f and the second central axis C2, respectively.

[0108] The signals (voltages) output from the first oscillators 52a to 52f and the second oscillator 53 are amplified by the corresponding receiving units 13a to 13g, converted into digital signals (digital values), and output as received signals (original received signals) in each direction of the first center axes C1a to C1f and the second center axis C2.

[0109] These original reception signals are subjected to spatial (and temporal) filtering by the filter 14. In addition, the filter 14 sets a virtual direction at a midpoint between adjacent first center axes C1a-C1f with respect to each of the first center axes C1a-C1f, and generates reception signals from the reception signals of the first transducers 52a-52f, on the assumption that an ultrasonic wave TB is virtually transmitted and received in the virtual direction.

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

[0111] Then, a detection result image 22 in which the latest detection results in each azimuth direction are displayed as circles for the omnidirectional detection of the ship 71 is generated by the detection result image generating means 15. At this time, a water-bottom guide ring 25 is drawn by the water-bottom guide ring generating means 15a at the depth position of the water bottom SB in the vertical direction directly below the ship 71 in the detection result image 22. Then, the display control means 18 displays the detection result image 22 with the water-bottom guide ring 25 drawn on the display device 21 as shown in FIG.

[0112] According to the ultrasonic sonar device 1 configured as above, the transmitting units 11a and 11b drive the wave transmitting and receiving unit 50 so that ultrasonic waves TB are transmitted from the first transducers 52a-52f and the second transducer 53 into the water in all directions relative to the ship 71 set in a predetermined range. Then, the reflected waves of the ultrasonic waves TB reflected from each position in the water for each of the first central axes C1a-C1f and the second central axis C2, which are predetermined directions, are received by the first transducers 52a-52f and the second transducer 53 of the wave transmitting and receiving unit 50, respectively. Based on the reflected waves received by the wave transmitting and receiving unit 50, reception signals are generated for each predetermined direction by the receiving units 13a-13g and the filter 14.

[0113] Based on the generated reception signals for each predetermined direction, a detection result image 22 showing the latest detection result over a predetermined range is generated by the detection result image generating means 15. From this detection result image 22, it is possible to determine at least the presence or absence of a detection target GF within the predetermined range and the direction in which the detection target GF currently exists.

[0114] Here, the first transducers 52a-52f are fixed to the transducer unit 50 so that their first central axes C1a-C1f are in a predetermined direction and are positioned at a predetermined angle θ with respect to the vertical direction when the transducer unit 50 is attached to the ship 71. Each of the first transducers 52a-52f has a predetermined directional characteristic so as to include at least the first central axes C1a-C1f of the adjacent first transducers 52a-52f and the vertical direction. This allows the small number of first transducers 52a-52f to simultaneously transmit ultrasonic waves TB over a predetermined range and receive the reflected waves to detect the detection target GF. Therefore, the ultrasonic sonar device 1 can achieve high-speed detection at low cost.

[0115] Furthermore, the wave 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 wave transmitting and receiving unit 50 such that the second central axis C2 is positioned in the vertical direction when the wave 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, it is possible to detect the detection target GF in the vertical direction with high accuracy.

[0116] Furthermore, when performing underwater detection over a predetermined range by horizontal detection of the sonar function, the transmission of ultrasonic waves TB from the second transducer 53 is turned off, or the intensity of the ultrasonic waves TB transmitted from the second transducer 53 is made smaller than the intensity of the ultrasonic waves TB transmitted from the first transducers 52a to 52f. This makes it possible to eliminate reflected waves of the ultrasonic waves TB transmitted from the second transducer 53 from the bottom SB in the vertical direction directly below the ship 71, or to reduce the intensity of the reflected waves received by the first transducers 52a to 52f after the ultrasonic waves TB transmitted from the second transducer 53 are reflected from the bottom SB in the vertical direction of the ship 71.

[0117] Therefore, in an oblique direction (the direction of the first central axes C1a-C1f) from the ship 71 where detection is performed by the first transducers 52a-52f, a detection target GF present at a distance approximately the same as the depth of the water bottom SB in the vertical direction directly below the ship 71 can be prevented from being buried in the reflected waves from the water bottom SB in the vertical direction, making it easier to detect. Therefore, the ultrasonic sonar device 1 can achieve high-speed detection at low cost, and can prevent the detection target GF from being buried in the reflected waves from the water bottom SB in the vertical direction.

[0118] In addition, in the ultrasonic sonar device 1, the depth of the bottom SB in the vertical direction directly below the ship 71 on which the wave transmitting and receiving unit 50 is provided is determined by the bottom guide ring generating means 15a based on the intensity of the reflected wave received by the wave transmitting and receiving unit 50. Then, the bottom guide ring 25 is drawn by the bottom guide ring generating means 15a on the detection result image 22 at the position of the depth of the bottom SB in the vertical direction directly below the ship 71 determined by the bottom guide ring generating means 15a. Before receiving the reflected wave from the bottom SB in the direction of the first central axes C1a to C1f, the first transducers 52a to 52f first receive the reflected wave from the bottom SB in the vertical direction directly below the ship 71, but the bottom guide ring 25 attached to the detection result image 22 can clearly indicate to the user that the detection result displayed beyond the depth of the bottom SB in the vertical direction directly below the ship 71 is invalid.

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

[0120] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and it can be easily assumed that various improvements and modifications are possible within the scope of the present invention. For example, each embodiment may be modified by adding a part or a plurality of parts of the configuration of each other embodiment to the embodiment, or by replacing a part or a plurality of parts of the configuration of the embodiment, including the modified examples described below. In addition, the numerical values ​​given in the above embodiments are merely examples, and other numerical values ​​can be naturally adopted.

[0121] In the above embodiment, the first transducers 52a-52f are inclined with their acoustic radiation surfaces facing inward (towards the side where the second transducer 53 is located), but this is not necessarily limited to the above, and the first transducers 52a-52f may be inclined with their acoustic radiation surfaces facing outward (towards the side opposite to the side where the second transducer 53 is located). In this case, too, it is preferable that each of the first central axes C1a-C1f forms a predetermined angle θ with the second central axis C2 (the vertical direction when the wave transmitting and receiving unit 50 is attached to the ship 71) selected from the range of 20° or more and 50° or less.

[0122] In the above embodiment, the case has been described in which the first transducers 52a to 52f are arranged around the second transducer 53 in the wave transmitting and receiving unit 50. However, the method of arranging the first transducers 52a to 52f and the second transducer 53 in the wave transmitting and receiving unit 50 may be arbitrary, as long as, from a broad perspective, when the wave transmitting and receiving unit 50 is attached to the ship 71, the second central axis C2 is in the vertical direction, the first central axes C1a to C1f form a predetermined angle θ with respect to the second central axis C2 (in other words, the vertical direction), and the first central axes C1a to C1f are in a predetermined direction. For example, the first oscillators 52a to 52f and the second oscillator 53 may be arranged in one row or two rows, or the first oscillators 52a to 52f may be arranged in two rows and the second oscillator 53 may be arranged at any position between the two rows of the first oscillators 52a to 52f.

[0123] In the above embodiment, a case has been described in which detection is performed over a predetermined range set in all directions of the ship 71, but the predetermined range may be set in a portion of all directions of the ship 71. In this case, the first range may be set to a portion or the entirety of the predetermined range. Furthermore, the second range may be set to a portion or the entirety of the predetermined range as long as it is different from the first range. [Explanation of symbols]

[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 Filters 15 Detection result image generation means 15a Bottom guide ring generating means 18 Display control means 21 Display device 22 Detection result image 25 Bottom guide ring 50 Transmitter / receiver unit 52 First transducer 52a First transducer 52b First transducer 52c 1st transducer 52d First transducer 52e First transducer 52f 1st transducer 53 Second transducer 71 Ship C1a 1st central axis C1b 1st central axis C1c 1st central axis C1d 1st central axis C1e 1st center axis C1f 1st central axis C2 2nd central axis GF Detectable object SB underwater TB ultrasound θ angle

Claims

1. A wave transmitting / receiving unit that is attached to a vessel and capable of transmitting ultrasonic waves over a predetermined range underwater set in all or some directions from the vessel, and receiving reflected waves of the ultrasonic waves reflected from each position underwater for each predetermined direction; an ultrasonic transmission driving means for driving the transmission of ultrasonic waves from the wave transmitting / receiving unit; a reception signal generating means for generating a reception signal for each of the predetermined directions based on the reflected wave received by the wave transmitting / receiving unit; a detection result image generating means for generating a detection result image showing the latest detection result over the predetermined range based on the reception signal for each of the predetermined directions generated by the reception signal generating means, The wave transmitting and receiving unit includes: A plurality of first transducers having a predetermined directional characteristic with respect to a central axis; a second transducer fixed so that a central axis of the second transducer is positioned in a vertical direction when the wave transmitting and receiving unit is attached to the vessel; each of the plurality of first transducers is fixed such that its central axis is in the predetermined direction and is at a predetermined angle with respect to a vertical direction when the wave transmission / reception unit is attached to the ship; and the plurality of first transducers have the predetermined directional characteristics so as to include at least the central axes of adjacent first transducers and the vertical direction; The ultrasonic sonar device is characterized in that the ultrasonic transmission driving means turns off the transmission of ultrasonic waves from the second transducer or makes the intensity of the ultrasonic waves transmitted from the second transducer smaller than the intensity of the ultrasonic waves transmitted from the first transducer during the period when underwater detection over the specified range is performed.

2. a bottom depth determining means for determining a bottom depth in a vertical direction of a ship on which the wave transmitting and receiving unit is provided, based on the intensity of the reflected wave received by the wave transmitting and receiving unit; 2. The ultrasonic sonar device according to claim 1, wherein the detection result image generating means draws a predetermined mark on the detection result image at the position of the depth of the water bottom determined by the water bottom depth determining means.

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

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