Underwater positioning device, underwater vehicle, underwater positioning system, underwater positioning method, and underwater positioning program

Abstract

To provide an underwater positioning device, an underwater sailing body, an underwater positioning system, an underwater positioning method, and an underwater positioning program capable of easily separating a positioning object device.SOLUTION: An underwater positioning device 50 includes a grouping section 51 for grouping multiple positioning object devices into multiple groups for each depth and allocating a predetermined, different frequency for each group, a transmission section 52 for transmitting transmission signals having predetermined, different frequencies, a reception section 53 for receiving a response signal that is sent from a positioning object device, and is allocated by the grouping section 51 and has a predetermined frequency, a frequency separation section 54 for performing band separation according to frequencies for a received response signal, and an array processing section 55 for performing array signal processing to the band-separated response signal, and performing simultaneous positioning and communication of multiple positioning object devices included in one group, and response signals having the same frequency are transmitted from a positioning object device for each group from among multiple groups.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This disclosure relates to an underwater positioning device, an underwater vehicle, an underwater positioning system, an underwater positioning method, and an underwater positioning program. [Background technology]

[0002] One positioning method that uses acoustic signals to measure the position of a device underwater is the SSBL (Super Short Base Line) method. In the SSBL method, distance is measured based on the time difference between transmission and reception when the device to be positioned sends a response signal in response to a question signal transmitted by the device itself. At the same time, multiple receivers are placed at short intervals, and the phase difference of the response signals received from the device to be positioned is measured by each receiver to measure the angle of the arriving response signal and calculate the position of the device to be positioned. For example, Patent Document 1 discloses that the received response signal is processed by quadrature detection, downsampling, and low-pass filtering to improve positioning accuracy. In Patent Document 1, the position of the device to be positioned is determined from the time difference that is the time of the maximum value of the correlation function for the processed response signal. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 4968827 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the invention described in Patent Document 1 uses the SBL (Short Base Line) method, and the SBL and SSBL methods have the problem that they cannot accurately measure sound waves arriving simultaneously from multiple directions at the same frequency.

[0005] To simultaneously position multiple target devices using the SSBL method, each device must be assigned a different frequency. The SSBL receiver then needs to individually separate and extract the response signals for each frequency and measure the phase difference for each frequency. However, there is an upper limit to the number of usable frequency bands, which limits the number of devices that can be simultaneously positioned.

[0006] Furthermore, when considering the application of the SSBL method to swarm control where a single receiver (master unit) positions a large number of positioning target devices (slave units) and communicates with a large number of positioning target devices (slave units) to act in a swarm, the number of positioning target devices (slave units) that can be controlled is limited by the number of frequency bands available in the receiver (master unit). If it is necessary to control more positioning target devices (slave units) than the number of frequency bands available in the receiver (master unit), it is conceivable to divide the positioning target devices (slave units) into several groups and measure each group sequentially using time-division multiplexing. However, using time-division multiplexing would require a considerable amount of time to complete the positioning and communication of all positioning target devices (slave units) in one cycle. If the time required to complete the positioning and communication of all positioning target devices (slave units) in one cycle is long, it becomes difficult to respond immediately when the formation of positioning target devices (slave units) is dense or when emergency actions such as obstacle avoidance are performed, making time-division multiplexing disadvantageous.

[0007] This disclosure is made in view of these circumstances and aims to provide an underwater positioning device, an underwater vehicle, an underwater positioning system, an underwater positioning method, and an underwater positioning program that can easily separate multiple positioning target devices. [Means for solving the problem]

[0008] To solve the above problems, the underwater positioning device, underwater vehicle, underwater positioning system, underwater positioning method, and underwater positioning program of this disclosure employ the following means. The underwater positioning device of this disclosure includes: a grouping unit that groups a plurality of positioning target devices by depth and divides them into a plurality of groups, and assigns a different predetermined frequency to each group; a transmitting unit that transmits a plurality of transmission signals of the predetermined frequencies; a receiving unit that receives response signals from a plurality of positioning target devices to the transmission signals, the response signals of the predetermined frequencies assigned by the grouping unit; a frequency separation unit that performs frequency-based band separation on the received response signals; and an array processing unit that performs array signal processing on the band-separated response signals to perform simultaneous positioning of a plurality of positioning target devices included in one of the groups and communication with the plurality of positioning target devices, wherein the same frequency response signal is transmitted from each of the same groups among the plurality of groups.

[0009] The underwater vehicle of this disclosure is equipped with the aforementioned underwater positioning device.

[0010] The underwater positioning system of this disclosure comprises the aforementioned underwater vehicle and a plurality of vehicle-to-position vehicles equipped with positioning target devices.

[0011] The underwater positioning method of this disclosure involves a computer executing the following steps: a grouping step of dividing a plurality of positioning target devices into a plurality of groups by depth and assigning a different predetermined frequency to each group; a transmission step of transmitting multiple transmission signals of the predetermined frequencies; a receiving step of receiving response signals from the plurality of positioning target devices to the transmission signals, the response signals of the predetermined frequencies assigned by the grouping step; a frequency separation step of performing frequency-based band separation on the received response signals; and an array processing step of performing array signal processing on the band-separated response signals to perform simultaneous positioning of the plurality of positioning target devices included in one group and communication with the plurality of positioning target devices, wherein the response signals of the same frequency are transmitted from each of the same groups among the plurality of groups.

[0012] The underwater positioning program of the present disclosure causes a computer to execute the aforementioned underwater positioning method.

Effect of the Invention

[0013] According to the present disclosure, when the underwater positioning device performs simultaneous positioning and communication of the positioning target devices, the limit number of the positioning target devices that can be controlled simultaneously can be increased.

Brief Description of the Drawings

[0014] [Figure 1] It is a diagram showing an underwater positioning system in some embodiments of the present disclosure. [Figure 2] It is a diagram showing an example of the hardware configuration of a control device in some embodiments of the present disclosure. [Figure 3] It is a diagram showing an example of the functions of an underwater positioning device in some embodiments of the present disclosure. [Figure 4] It is a diagram showing the transmission and reception processing of an underwater positioning device in some embodiments of the present disclosure. [Figure 5] It is a diagram showing the processing by a frequency separation unit and an array processing unit in some embodiments of the present disclosure. [Figure 6] It is a diagram showing an example of the installation form of a wave receiver in some embodiments of the present disclosure. [Figure 7] It is a diagram showing an example of the standby state of a wave receiver in some embodiments of the present disclosure. [Figure 8] It is a diagram showing the phase adjustment processing in some embodiments of the present disclosure. [Figure 9] It is a diagram showing the demodulation processing in some embodiments of the present disclosure. [Figure 10] It is a diagram showing the control flow of an underwater positioning device in some embodiments of the present disclosure. [Figure 11] It is a diagram showing the adaptive phase adjustment processing in some embodiments of the present disclosure. [Figure 12] It is a diagram showing an example of the installation form of a wave receiver in some embodiments of the present disclosure. [Figure 13]This figure shows an example of a receiver installation configuration in some embodiments of the present disclosure. [Modes for carrying out the invention]

[0015] An embodiment of the underwater positioning device, underwater vehicle, underwater positioning system, underwater positioning method, and underwater positioning program related to this disclosure will be described below with reference to the drawings. [First Embodiment] The first embodiment of this disclosure will be described below with reference to Figure 1. Figure 1 shows an underwater positioning system in several embodiments of the present disclosure. As shown in Figure 1, the underwater positioning system 1 comprises a master underwater vehicle 10, slave vehicles 21a, 21b, 21c, 21d, 21e, 21f, 22a, 22b, 22c, 22d, 22e, 22f, 23a, 23b, 23c, 23d, 23e, 23f, 24a, 24b, 24c, 24d, 24e, 24f, and an underwater positioning device 50. In the following explanation, when distinguishing between the positioning target vessels 21, 22, 23, and 24, one of a, b, c, d, e, or f will be added to the end of their names. When not distinguishing between the positioning target vessels 21, 22, 23, and 24, a, b, c, d, e, or f will be omitted.

[0016] The underwater vehicle 10 is equipped with an underwater positioning device 50 for measuring the positions of multiple positioning target vehicles 21, 22, 23, and 24, and navigates underwater. The underwater vehicle 10 navigates underwater as shown in Figure 1, but it may also move on the water surface.

[0017] There are multiple positioning target vessels 21, 22, 23, and 24, and each of these vessels 21, 22, 23, and 24 navigates the water in a group. Each positioning target vessel 21, 22, 23, and 24 is equipped with a positioning target device (not shown) that communicates with the underwater positioning device 50 of the underwater vessel 10. Although communication with the underwater positioning device 50 is performed by the positioning target device (not shown), for convenience, the following explanation will assume that the positioning target vessels 21, 22, 23, and 24 equipped with the positioning target device communicate with the underwater positioning device 50.

[0018] The target vehicles 21, 22, 23, and 24 are, for example, UUVs (Unmanned Undersea Vehicles). In UUVs, the depth sensor, which is a sensor that senses and controls the depth, has less drift in its depth sensor value compared to the horizontal position sensor value, making it easy to have multiple UUVs navigate at the same depth. Therefore, groups can be pre-configured for each depth.

[0019] The underwater positioning device 50 is installed on the underwater vehicle 10 and is used to measure the positions of the target vehicles 21, 22, 23, and 24. In this embodiment, the underwater positioning device 50 is installed on the lower part of the underwater vehicle 10 and communicates with the target vehicles 21, 22, 23, and 24 that are navigating at a deeper depth than the underwater vehicle 10. The underwater positioning device 50 may also be installed on the upper part of the underwater vehicle 10, but since the receiver SR of the underwater positioning device 50, which will be described later, is directional, in this case it is desirable that the target vehicles 21, 22, 23, and 24 are navigating at a shallower depth than the underwater vehicle 10. The underwater positioning device 50 may be installed on both the lower and upper parts of the underwater vehicle 10. The underwater positioning device 50 is equipped with a receiver SR, which will be described later, and communicates with the target vehicles 21, 22, 23, and 24 via the receiver SR.

[0020] Figure 2 is a diagram showing an example of the hardware configuration of a control device in some embodiments of the present disclosure. As shown in Figure 2, the underwater positioning device (controller) 50 is equipped with a computer system, which includes, for example, a CPU (Central Processing Unit: processor) 1100, secondary storage (ROM: memory) 1200, main memory (RAM: main memory) 1300, a hard disk drive (HDD) 1400 as a mass storage device, and a communication unit 1500 for connecting to a network, etc. A solid-state drive (SSD) may be used as the mass storage device. These components are connected via a bus 1800.

[0021] The CPU 1100 controls the entire underwater positioning device 50 using an OS (Operating System) stored in a secondary storage device 1200 connected via a bus 1800, and also performs various processes by executing various programs stored in the secondary storage device 1200. One or more CPUs 1100 may be provided and may cooperate with each other to achieve processing.

[0022] The main memory 1300 consists of writable memory such as cache memory and RAM (Random Access Memory), and is used as a work area for reading the CPU 1100's executable program and writing processing data by the executable program.

[0023] The secondary storage device 1200 is a non-transitory computer-readable storage medium. Examples of secondary storage devices 1200 include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memory. Examples of secondary storage devices 1200 include ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), and flash memory. The secondary storage device 1200 stores, for example, an OS for controlling the entire information processing device such as Windows®, iOS®, and Android®, a BIOS (Basic Input / Output System), various device drivers for hardware operation of peripheral devices, various application software, and various data and files. Furthermore, the secondary storage device 1200 stores programs for implementing various processes and various data required to implement those processes. Multiple secondary storage devices 1200 may be provided, and the aforementioned programs and data may be divided and stored in each secondary storage device 1200.

[0024] Furthermore, the underwater positioning device 50 may include an input unit consisting of a keyboard or mouse, and a display unit consisting of a liquid crystal display device or the like for displaying data. It may also include a notification unit that includes a display unit and outputs lights, sounds, and especially alarm sounds, such as a speaker.

[0025] Figure 3 is a diagram illustrating an example of the function of an underwater positioning device in several embodiments of the present disclosure. As shown in Figure 3, the underwater positioning device 50 includes a grouping unit 51, a transmitting unit 52, a receiving unit 53, a frequency separation unit 54, and an array processing unit 55.

[0026] A series of processes for realizing the functions of the underwater positioning device 50 are stored in the form of a program in a secondary storage device 1200 (see Figure 2), for example. The CPU (processor) 1100 (see Figure 2) reads this program into the main memory 1300 (see Figure 2) and performs information processing and calculations to realize various functions. The program may be pre-installed in the secondary storage device 1200, provided stored in other non-temporary computer-readable storage media, or distributed via wired or wireless communication. Examples of non-temporary computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memory.

[0027] The grouping unit 51 shown in Figure 3 divides multiple positioning target devices into multiple groups by depth, and assigns a different predetermined frequency to each group. Multiple navigational objects 21, 22, 23, and 24 are grouped by depth by the grouping unit 51. As shown in Figure 1, navigational objects 21a, 21b, 21c, 21d, 21e, and 21f are assumed to be traveling at approximately the same depth as a single group, as described above, and are designated as group 31. Similarly, navigational objects 22a, 22b, 22c, 22d, 22e, and 22f are assumed to be traveling at approximately the same depth and are designated as group 32, navigational objects 23a, 23b, 23c, 23d, 23e, and 23f are assumed to be traveling at approximately the same depth and are designated as group 33, and navigational objects 24a, 24b, 24c, 24d, 24e, and 24f are assumed to be traveling at approximately the same depth and are designated as group 34.

[0028] The grouping unit 51 assigns a different predetermined frequency to each of the groups 31, 32, 33, and 34. That is, for example, the positioning target vessels 21a, 21b, 21c, 21d, 21e, and 21f in group 31 are assigned the same predetermined frequency. The positioning target vessels 21a, 21b, 21c, 21d, 21e, and 21f communicate with the underwater positioning device 50 using the same predetermined frequency.

[0029] The predetermined frequencies assigned to each group 31, 32, 33, and 34 can be any frequency. Since lower frequencies travel longer distances, in this embodiment, the lowest frequency among the multiple frequencies to be assigned may be assigned to group 34, which is the longest distance from the underwater positioning device 50. Furthermore, other predetermined frequencies may be assigned to the other groups 31, 32, and 33, respectively, depending on their distance from the underwater positioning device 50. In addition, the bandwidths of the multiple frequencies to be assigned may be made wider and each bandwidth may be divided into larger sections. By making each bandwidth wider and dividing it into larger sections, the amount of information in each bandwidth can be increased.

[0030] In this way, by assigning frequencies in advance to each depth in which the target vessels 21, 22, 23, and 24 navigate, the depth can be automatically determined when the frequency band is separated in the frequency separation unit 54 described later. Therefore, the underwater positioning device 50 does not need to perform positioning of the target vessels 21, 22, 23, and 24 in three dimensions. Since the underwater positioning device 50 only needs to perform two-dimensional processing in the horizontal plane, there is no need to array the receivers described later in the elevation direction, and the device configuration can be simplified.

[0031] The transmitting unit 52 transmits multiple transmission signals of different predetermined frequencies. In this embodiment, the transmitting unit 52 transmits a transmission signal that includes questions and information to be distributed to multiple positioning target vehicles 21, 22, 23, and 24, for example. The transmission signal is also referred to as a question signal. The transmitting unit 52 anticipates the time required for receiving response signals by the receiving unit 53 (described later) and processing by the frequency separation unit 54 and array processing unit 55 (described later), and transmits the next transmission signal at an appropriate interval.

[0032] The receiving unit 53 receives response signals from the positioning target vessels 21, 22, 23, and 24 to the transmitted signal, which are response signals of a predetermined frequency assigned by the grouping unit 51. The positioning target vessels 21, 22, 23, and 24 respond to the transmitted signal from the underwater positioning device 50 with a response signal. The response signal includes an answer to a question and may include, for example, the status (identifier, etc.) of the positioning target vessels 21, 22, 23, and 24. The positioning target vessels 21, 22, 23, and 24 can add information to the response signal by modulating it.

[0033] Figure 4 shows the transmission and reception processing of an underwater positioning device in several embodiments of the present disclosure. In Figure 4, the signals and timings transmitted by the underwater positioning device 50 are shown by thick lines, the signals and timings transmitted by each positioning target vessel 21 in group 31 are shown by dashed lines, the signals and timings transmitted by each positioning target vessel 22 in group 32 are shown by solid lines, and the signals and timings transmitted by each positioning target vessel 23 in group 33 are shown by dashed lines.

[0034] For example, suppose that each positioning target vehicle 21 in group 31 is assigned a frequency in the f1 band, each positioning target vehicle 22 in group 32 is assigned a frequency in the f2 band, each positioning target vehicle 23 in group 33 is assigned a frequency in the f3 band, and each positioning target vehicle 24 in group 34 is assigned a frequency in the f4 band.

[0035] As shown in Figure 4, at time t1, the underwater positioning device 50 transmits a transmission signal containing questions and information to be distributed to the target vessels 21, 22, 23, and 24. Upon receiving the transmission signal, the target vessels 21, 22, 23, and 24 each transmit a response signal to the underwater positioning device 50 using a predetermined frequency assigned by the grouping unit 51, providing answers to the questions, including their status.

[0036] Each positioning target vessel 21 in group 31 transmits a response signal to the underwater positioning device 50 using a frequency in the f1 band, as shown by the dashed line. Similarly, each positioning target vessel 22 in group 32 transmits a response signal to the underwater positioning device 50 using a frequency in the f2 band, as shown by the solid line. Each positioning target vessel 23 in group 33 transmits a response signal to the underwater positioning device 50 using a frequency in the f3 band, as shown by the dashed line. Each response signal transmitted from each positioning target vessel 21, 22, and 23 may be a sound wave, ultrasound, or radio wave.

[0037] Each response signal transmitted from each of the positioning target vessels 21, 22, and 23 is transmitted in a specific direction and arrives at the underwater positioning device 50 at approximately the same time, where it is received by the receiving unit 53. At time t2, which is an appropriate interval from time t1, the underwater positioning device 50 transmits the next transmission signal, to which each of the positioning target vessels 21, 22, and 23 transmits a response signal.

[0038] The frequency separation unit 54 in Figure 3 performs frequency-based bandwidth separation on the response signals from the positioning target vessels 21, 22, 23, and 24 received by the receiving unit 53. The response signals from multiple positioning target vessels 21, 22, 23, and 24 are received simultaneously by the underwater positioning device 50 at approximately the same time. Furthermore, the response signals from the multiple positioning target vessels 21, 22, 23, and 24 are assigned different predetermined frequencies for each group 31, 32, 33, and 34. The frequency separation unit 54 uses the predetermined frequencies assigned to each group 31, 32, 33, and 34 to perform bandwidth separation of the response signals from each group 31, 32, 33, and 34.

[0039] The array processing unit 55 performs array signal processing on the response signals from multiple positioning target vessels 21, 22, 23, and 24 that have been band-separated by the frequency separation unit 54, and performs simultaneous positioning of multiple positioning target vessels 21, 22, 23, and 24 included in one group, and communication with multiple positioning target vessels 21, 22, 23, and 24. In array signal processing, the array processing unit 55 performs phase adjustment processing and demodulation processing.

[0040] Figure 5 shows the processing performed by the frequency separation unit and the array processing unit in some embodiments of the present disclosure. As shown in Figure 5, the response signal received by the receiving unit 53 is subjected to band separation processing by the frequency separation unit 54, and array processing, specifically phase adjustment and demodulation processing, is performed by the array processing unit 55 to acquire information on each of the positioning target vehicles 21, 22, 23, and 24.

[0041] The receiving unit 53 is equipped with multiple receivers SR. The receiving unit 53 is equipped with M receivers SR (receiver array) from receiver SR1 to receiver SRM. The multiple receivers SR in this embodiment function as a phased array. In the following explanation, when distinguishing between receivers SR, a number or symbol will be added to the end; when not distinguishing between receivers SR, the number or symbol will be omitted.

[0042] Figure 6 shows an example of a receiver installation configuration in some embodiments of the present disclosure. As shown in Figure 6, in this embodiment, the receivers SR are arranged sequentially in a circular pattern. Each receiver SR is positioned to face outwards from the circle and receives multiple signals coming from various directions in the direction of the outer circle. As mentioned above, response signals of predetermined frequencies that differ for each group are received simultaneously at approximately the same time.

[0043] The receivers SR1, SR2 to SRM of the receiving unit 53 in Figure 5 each receive a response signal. Each received response signal is subjected to band separation processing by the frequency separation unit 54. The frequency separation unit 54 separates the signals into bands that differ for each group, which in this embodiment are the f1 band, f2 band, f3 band, and f4 band.

[0044] Figure 7 shows an example of the standby state of a receiver in some embodiments of the present disclosure. As shown in Figure 7, in this embodiment, each receiver SR is θ1, θ2, ..., θ s1 , , , θ s2, ···, θ K Forms beams (waiting beams) at each of these angles and awaits response signals from each of the positioning target vessels 21, 22, 23, 24.

[0045] Each receiver SR is for the angle θ s1 Assume that in the beam of, it receives the response signal from the positioning target vessel 21a, and in the beam of the angle θ s2 Assume that it receives the response signal from the positioning target vessel 21b. Since the response signals of the positioning target vessels 21a and 21b received by each receiver SR belong to group 31, they are separated into the f1 band in the frequency separation unit 54.

[0046] The response signals separated by band in the frequency separation unit 54 of FIG. 5 are subjected to array processing (phasing processing) in the array processing unit 55. The underwater positioning device 50 performs phasing processing, which is a process for imparting directivity using a receiver array. By performing phasing processing, waves from a desired direction can be emphasized and waves from directions other than the desired direction can be reduced.

[0047] FIG. 8 is a diagram showing phasing processing in some embodiments of the present disclosure. As shown in FIG. 8, receivers SR1, SR2, ···, SRM each receive a response signal. In this embodiment, for example, assume that the response signals received by each receiver SR are separated into the f1 band.

[0048] Let the distances from the reference positions of the receivers SR1, SR2, ···, SRM be d1, d2, ···, d M respectively. Also, let the array signals, which are the observation signals of the receivers SR1, SR2, ···, SRM, be x1(t), x2(t), ···, x M (t) respectively. Here, t represents time.

[0049] In phasing processing, the phases of the array signals x m (t) (m = 1, 2, ···, M) input from each receiver SR are displaced by the phase shift amounts e jΦs,m corresponding to each, and the array signals whose phases are displaced and phased are output to the adder 81.

[0050] Each phase-corrected array signal is added by the adder 81, and the array output signal b s (t)(s=1, 2, ..., K) is output.

[0051] The above phase-alignment process (delayed sum phase-alignment process) is represented by equation (1).

[0052]

number

[0053] The response signal, after phase adjustment processing in the array processing unit 55 in Figure 5, is output as an array output signal, followed by demodulation processing. The array output signal is demodulated into beam signals equal to the number of positioning target vehicles 21, 22, 23, and 24 in the same bandwidth.

[0054] Figure 9 shows the demodulation process in some embodiments of the present disclosure. In Figure 9, the upward axis (vertical axis) represents the array output signal, the horizontal axis (horizontal axis) represents time, and the forward axis represents the phase alignment direction.

[0055] In phase alignment processing, the angle (phase alignment direction) θ of the waiting beam of each receiver SR s Array output signal b for each (s=1, 2, ..., K) s (t)(s=1, 2, ..., K) is output. In Figure 9, the beam signal is the array output signal b s1 (t) and b s2 (t) is shown by a dashed line.

[0056] As shown in Figure 9, the array output signal b s1 (t) and b s2 (t) has different arrival times at each receiver SR. Each array output signal b s The time difference in the arrival times of (t) represents the distance between the positioning target vessels 21, 22, 23, and 24 and each receiver SR (i.e., underwater positioning device 50). The array processing unit 55 processes each array output signal b sThe time difference in the arrival times of (t) is measured, and the time difference is converted into distance to derive the distance to the positioning target vehicles 21, 22, 23, and 24.

[0057] As shown in Figure 9, the array output signal b s1 (t) and b s2 (t) is a beam signal with amplitude. Each array output signal b s The amplitude of (t) corresponds to each array output signal b s (t) indicates the direction of arrival, that is, it represents the direction of the positioning target vehicles 21, 22, 23, and 24. The array processing unit 55 processes each array output signal b s The bearings of the target vehicles 21, 22, 23, and 24 are derived from the amplitude of (t).

[0058] The array processing unit 55 in Figure 5 processes each array output signal b s Demodulation processing is performed on (t) to demodulate the response signals from the positioning target vessels 21, 22, 23, and 24. The array processing unit 55 obtains the status of the positioning target vessels 21, 22, 23, and 24 from the response signals demodulated into digital signals. Existing methods can be used for demodulation in the demodulation processing.

[0059] By performing the above processing, the underwater positioning device 50 can simultaneously determine the location of each of the positioning target vessels 21, 22, 23, and 24 at the time of observation, as well as the three-dimensional position and information of a large number of positioning target vessels 21, 22, 23, and 24.

[0060] Figure 10 shows the control flow of an underwater positioning device in several embodiments of the present disclosure. In step S101, the grouping unit 51 of the underwater positioning device 50 divides the multiple positioning target vessels 21, 22, 23, and 24 into multiple groups by depth, and assigns a different predetermined frequency to each group.

[0061] In step S102, the transmitting unit 52 transmits a transmission signal (question signal), which is a signal containing questions and information to be distributed to the multiple positioning target vehicles 21, 22, 23, and 24.

[0062] In step S103, the receiving unit 53 receives response signals from the positioning target vehicles 21, 22, 23, and 24 to the transmission signal transmitted by the transmitting unit 52, and the response signals use predetermined frequencies assigned by the grouping unit 51.

[0063] In step S104, the frequency separation unit 54 performs frequency-based band separation on the response signals from the positioning target vehicles 21, 22, 23, and 24 received by the receiving unit 53.

[0064] In step S105, the array processing unit 55 performs phase adjustment and demodulation processing on the response signals from the multiple positioning target vessels 21, 22, 23, and 24 that have been band-separated by the frequency separation unit 54, and performs simultaneous positioning of the multiple positioning target vessels 21, 22, 23, and 24 included in one group, and communicates with the multiple positioning target vessels 21, 22, 23, and 24.

[0065] [Second Embodiment] A second embodiment of this disclosure will be described below with reference to Figure 11. In the first embodiment, phase shaping was performed using delayed summing, but the same process can be performed in the case of adaptive phase shaping if MVDR (Minimum Variance Distortionless Response) is used. In this embodiment, adaptive phase shaping using MVDR will be described.

[0066] When using fixed beamforming, a commonly used phase-shaping technique, the beam width is wide and does not meet the desired resolution, which can make it impossible to distinguish between multiple simultaneous response signals, especially adjacent response signals. In this case, the bit error rate (BER; the ratio of incorrect data to all data received by the receiver) may deteriorate.

[0067] The ability to separate multiple simultaneous response signals, especially adjacent ones, depends on the beam width. Narrow beams tend to have strong directivity and intensity, resulting in higher discrimination capabilities.

[0068] Therefore, in this embodiment, adaptive phase shaping is used. Adaptive phase shaping narrows the beam width, which improves the separation rate and resolution of the orientations of multiple response signals, thereby increasing the accuracy regarding the orientation from which the response signals arrive.

[0069] Figure 11 shows an adaptive phase adjustment process in several embodiments of the present disclosure. As shown in Figure 11, the response signals received by each receiver SR are s1(t), s2(t), ..., s M Let (t) be the time. Here, t represents time.

[0070] Each response signal s1(t), s2(t),...,s M For (t), the phaser has weights w1*, w2*, ..., w M * is set. Weights w1*, w2*, ..., w M By setting *, the directivity of multiple receiver SRs can be arbitrarily set. Weights w1*, w2*, ..., w M * is set by applying the weight generation algorithm 92 to the array output signal according to the angle of the response signal in order to adjust the amplitude and phase of the received signal by the receiver SR. Weights w1*, w2*, ..., w are set for the received signal. M Applying * gives the signal weights for the corresponding angles. Thus, weights w1*, w2*, ..., w M * acts as an adjustment element for the signal reception angle by receiver SR, which can improve accuracy at the relevant angle. Each weighted response signal is output to adder 91.

[0071] Each weighted response signal is added by the adder 91, and the array output signal b(t) is output.

[0072] [Third Embodiment] A third embodiment of this disclosure will be described below with reference to Figure 12. In the first and second embodiments, the receivers SR were arranged in a circular pattern and positioned to face outwards from the circle. However, in this embodiment, they are arranged in a shape other than a circle.

[0073] Figure 12 shows an example of a receiver installation configuration in some embodiments of the present disclosure. As shown in Figure 12, in this embodiment, the receivers SR are arranged in a linear array in a straight line. Each receiver SR is positioned to face a direction perpendicular to the direction in which the straight lines of the linear array extend (perpendicular direction).

[0074] Each receiver SR detects waves arriving from within a range of ±45 degrees in the front direction on the edge of the linear array. If the front direction of receiver SR1 is the direction of the dashed line in the diagram extending from receiver SR1, then receiver SR1 will detect waves in the range represented by the solid lines, which is 45 degrees to the right of the dashed line and 45 degrees to the left of the dashed line. By setting it in this way, for the edge on which receiver SR1 is placed, the point where two virtual extensions passing through each end of the linear array (shown as dashed lines passing through each end of the linear array in Figure 12) intersect perpendicularly is defined as the vertex, and the direction perpendicular to the edge on which receiver SR1 is placed (the direction perpendicular to the edge) from the vertex is defined as the front of the edge, and waves arriving from a range of 45 degrees to the left and right, a total range of 90 degrees, can be detected. If the underwater positioning device 50 is only positioned in a specific direction, the receiver SR has high sensitivity in the forward direction and is more likely to pick up waves in that direction. Therefore, each receiver SR should be positioned to cover the relevant direction.

[0075] The number of receiver SRs can be any number, but a larger number is preferable to improve accuracy. Preferably, the number of receiver SRs is the number of positioning target vehicles 21, 22, 23, and 24 included in group 1 plus 1 or more.

[0076] The arrangement of the receiver SR may be a polygon, for example, a quadrilateral. Figure 13 shows an example of a receiver installation configuration in some embodiments of the present disclosure. As shown in Figure 13, in this embodiment, the receivers SR are arranged in a linear array, and these arrays are arranged on each side of a quadrilateral polygon formed by combining them. Each receiver SR is positioned to face outwards from the polygon.

[0077] Each receiver SR detects waves arriving from within ±45 degrees in the front direction on each side. If the front direction of receiver SR1 is the direction of the dashed line in the diagram extending from receiver SR1, then receiver SR1 will detect waves within the range represented by the solid lines, which is 45 degrees to the right of the dashed line and 45 degrees to the left of the dashed line. With this setting, for each side where receiver SR1 is placed, waves arriving from within a range of 45 degrees to the left and right of the center of the quadrilateral, totaling 90 degrees, can be detected, with the direction perpendicular to the side where receiver SR1 is placed (the direction perpendicular to the side) being considered the front of the side. Furthermore, the same arrangement and settings are applied to each other side. This allows for a detection range of 360 degrees with the center of the quadrilateral as the center of the circle.

[0078] It is known that receiver SRs have high sensitivity in the forward direction and are good at picking up waves coming from that direction, but are not good at picking up waves coming from the rear direction. Therefore, by arranging the receiver SRs in a quadrilateral shape, the receiver SRs only need to process signals coming from the forward direction, thus reducing the processing load on the receiver SRs.

[0079] The number of receiver SRs can be any number, but a larger number is preferable to improve accuracy. Preferably, the number of receiver SRs is the number of positioning target vehicles 21, 22, 23, and 24 included in group 1 plus 1 or more.

[0080] The arrangement of the receiver SR may be a polygon other than a quadrilateral. In this case, the range of incoming waves to be detected by the receiver SR may be set according to the shape of the polygon, such that the detection range is a 360-degree range with the center of the polygon as the center of the circle.

[0081] Although several embodiments of this disclosure have been described in detail above with reference to the drawings, the specific configurations are not limited to these embodiments. For example, in some embodiments of the present disclosure described above, the response signals of the positioning target vessels 21, 22, 23, and 24 include answers to questions and, for example, the status of the positioning target vessels 21, 22, 23, and 24, but they may also include information regarding the depth of the positioning target vessels 21, 22, 23, and 24. This allows the underwater positioning device 50 to obtain the precise depth of each positioning target vessel 21, 22, 23, and 24.

[0082] <Note> The underwater positioning device, underwater vehicle, underwater positioning system, underwater positioning method, and underwater positioning program described in the embodiments above can be understood, for example, as follows.

[0083] A first aspect of the present disclosure of an underwater positioning device (50) includes: a grouping unit (51) that groups a plurality of positioning target devices by depth and divides them into a plurality of groups, and assigns a different predetermined frequency to each group; a transmitting unit (52) that transmits a plurality of transmission signals of the predetermined frequency; a receiving unit (53) that receives response signals from a plurality of positioning target devices to the transmission signals, the response signals of the predetermined frequency assigned by the grouping unit; a frequency separation unit (54) that performs frequency-based band separation on the received response signals; and an array processing unit (55) that performs array signal processing on the band-separated response signals to perform simultaneous positioning of a plurality of positioning target devices included in one group and communication with a plurality of positioning target devices, wherein the same frequency response signal is transmitted from each of the same groups among the plurality of groups.

[0084] By dividing multiple positioning devices into several groups in the depth direction using frequency multiplexing, and performing simultaneous positioning and communication in the horizontal direction using array signal processing, the number of positioning devices that can be simultaneously controlled by the underwater positioning device can be increased. Furthermore, since the depth direction can be determined by frequency, the underwater positioning device only needs to perform horizontal processing. This reduces the number of processes compared to 3D processing, and simplifies the device configuration.

[0085] In the second embodiment of the present disclosure, the underwater positioning device may, in the first embodiment, perform a delay summing and phase shaping process in the array signal processing to determine the horizontal direction and distance of the positioning target device.

[0086] In the third aspect of the present disclosure, the underwater positioning device may, in the first aspect, perform adaptive phase adjustment processing in the array signal processing to determine the horizontal direction and distance of the positioning target device.

[0087] In the underwater positioning device of the fourth aspect of this disclosure, in any of the first to third aspects, the receiving unit may be a linear array in which receivers are arranged in a straight line.

[0088] The receiving section has a linear array of receivers arranged in a straight line, which simplifies its configuration.

[0089] In the fifth aspect of the present disclosure, the underwater positioning device may, in any of the first to third aspects, have receivers arranged in a circular pattern and positioned so that they face outwards from the circle.

[0090] Because the receivers are arranged in a circular pattern, they can accurately receive response signals coming from all directions.

[0091] In the sixth aspect of the present disclosure, the underwater positioning device, in any of the first to third aspects, may have a receiving unit that is a polygonal type formed by combining a linear array of receivers arranged in a straight line, wherein the receivers are arranged so as to face the direction perpendicular to each side of the polygonal type.

[0092] Linear arrays have high sensitivity in the forward direction, and since each linear array only needs to process in the forward direction, the processing load on each linear array can be reduced.

[0093] The underwater vehicle (10) of the seventh aspect of this disclosure is equipped with an underwater positioning device according to any of the first to sixth aspects.

[0094] An underwater positioning system (1) according to the eighth aspect of this disclosure comprises an underwater vehicle according to the seventh aspect and a plurality of positioning target vehicles (21, 22, 23, 24) equipped with the positioning target device.

[0095] A ninth aspect of the present disclosure is an underwater positioning method in which a computer is made to perform the following steps: a grouping step of dividing a plurality of positioning target devices into a plurality of groups by depth and assigning a different predetermined frequency to each group; a transmission step of transmitting a plurality of transmission signals of the predetermined frequencies; a receiving step of receiving response signals from a plurality of positioning target devices to the transmission signals, the response signals of the predetermined frequencies assigned by the grouping step; a frequency separation step of performing frequency-based band separation on the received response signals; and an array processing step of performing array signal processing on the band-separated response signals to perform simultaneous positioning of a plurality of positioning target devices included in one group and communication with a plurality of positioning target devices, wherein the response signals of the same frequency are transmitted from each of the same groups among the plurality of groups.

[0096] The underwater positioning program of the tenth aspect of this disclosure causes a computer to execute the underwater positioning method of the ninth aspect. [Explanation of Symbols]

[0097] 1. Underwater positioning system 10 Underwater vehicle 21, 21a, 21b, 21c, 21d, 21e, 21f, 22, 22a, 22b, 22c, 22d, 22e, 22f, 23, 23a, 23b, 23c, 23d, 23e, 23f, 24, 24a, 24b, 24c, 24d, 24e, 24f Positioning target vehicle 50 Underwater positioning device 51 Grouping section 52 Transmitter 53 Receiving Unit 54 Frequency separation section 55 Array Processing Unit

Claims

1. A grouping unit that divides multiple positioning target devices into multiple groups by depth and assigns a different predetermined frequency to each group, A transmitting unit that transmits multiple transmission signals of the predetermined frequencies, A receiving unit that receives response signals from a plurality of positioning target devices to the transmission signal, wherein the response signals have a predetermined frequency assigned by the grouping unit, A frequency separation unit performs frequency-based bandwidth separation on the received response signal, An array processing unit performs array signal processing on the band-separated response signal and performs simultaneous positioning of multiple positioning target devices included in one group and communication with multiple positioning target devices, Includes, An underwater positioning device in which a response signal of the same frequency is transmitted from the positioning target device to each of the multiple groups.

2. The underwater positioning device according to claim 1, wherein in the array signal processing, a delay summing and phase shaping process is performed to determine the horizontal direction and distance of the positioning target device.

3. The underwater positioning device according to claim 1, wherein adaptive phase shaping is performed in the array signal processing to determine the horizontal direction and distance of the positioning target device.

4. The underwater positioning device according to claim 1, wherein the receiving unit is a linear array of receivers arranged in a straight line.

5. The receiving unit is an underwater positioning device according to claim 1, in which the receivers are arranged in a circular pattern and positioned so as to face outwards from the circle.

6. The receiving unit is a polygonal type, consisting of a linear array of receivers arranged in a straight line. The underwater positioning device according to claim 1, wherein the receiver is arranged to face the direction perpendicular to each side of the polygonal shape.

7. An underwater vehicle equipped with the underwater positioning device described in claim 1.

8. The underwater vehicle according to claim 7, An underwater positioning system comprising: a plurality of positioning target vehicles equipped with the aforementioned positioning target devices;

9. A grouping step involves dividing multiple positioning devices into multiple groups based on depth, and assigning a different predetermined frequency to each group. A transmission step of transmitting multiple transmission signals of predetermined frequencies, A receiving step of receiving response signals from a plurality of positioning target devices to the transmission signal, wherein the response signals have a predetermined frequency assigned by the grouping step, A frequency separation step is performed on the received response signal by performing frequency-based bandwidth separation, An array processing step which involves performing array signal processing on the band-separated response signal to perform simultaneous positioning of multiple positioning target devices included in one group and communication with multiple positioning target devices, Have the computer run it, An underwater positioning method wherein, for each of the multiple groups, the same response signal is transmitted from the positioning target device.

10. An underwater positioning program for causing a computer to execute the underwater positioning method described in claim 9.

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